17 PRESENT GROUNDWATER ARSENIC CONTAMINATION by yaofenjin

VIEWS: 15 PAGES: 63

									      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




PRESENT GROUNDWATER ARSENIC CONTAMINATION STATUS IN
                WEST BENGAL, INDIA


Dipankar Chakraborti, Ph.D., Mohammad Mahmudur Rahman, M.Sc., Uttam Kumar
Chowdhury, Ph.D., Kunal Paul, M.Sc., Mrinal Sengupta, M.Sc., Dilip Lodh,
PGDCA., Gautam Kumar Basu, Ph.D., Chitta Ranjan Chanda, Ph.D., Kshitish
Chandra Saha, MD, Subhash Chandra Mukherjee, MD, School of Environmental
Studies, Jadavpur University


Arsenic contamination in groundwater and consequent human suffering in West
Bengal, India was first reported in December 1983 when 63 arsenic patients from 3
villages were identified. At present 3000 villages are arsenic affected. Even after 14
years of our field survey we believe our study reflects only the tip of the iceberg in
identifying the extent of arsenic contamination. The area and population of these 9
arsenic affected districts of West Bengal are 38865 km2 and 42.7 million
respectively. Till to-date, we have analyzed by FI-HG-AAS 1,10,000 hand tube well
water samples from 9 arsenic affected districts. Out of them, 51% are unsafe to drink
according to the WHO recommended value of arsenic in drinking water (10 µg/L).
In our preliminary study, 95000 people were clinically examined from arsenic
affected districts of West Bengal and 10100 people (9.4% including 2% children)
were registered with arsenical skin lesions. At least 100 cancer and few hundreds
suspected Bowens disease were detected. Peripheral neuropathy is a common
finding to those having arsenical skin lesions. We have analyzed around 35000
biological samples collected from the arsenic affected villages and on average 85%
of the samples contain arsenic above normal level. Thus many people in the affected
villages may be sub-clinically affected. Children are more susceptible to arsenic
toxicity. Approximately 90% of the children below 11 years, living in arsenic
affected villages show elevated level of arsenic in hair and nails. Infants and children
might be at greater risk from arsenic toxicity due to more water consumption on body
weight basis. Villagers are using arsenic contaminated water not only for drinking
and cooking but also in agricultural field. Our study during last two years reveals the
presence of elevated level of inorganic arsenic in food chain and in those consumer
products where groundwater is used in affected villages. To combat this deadly
arsenic menace we need to increase awareness and educate our villagers about the
problem and instead of reckless use of groundwater we should preferably utilize our
vast available surface water, rain water with people’s participation.

CORRESPONDING AUTHOR: Dipankar Chakraborti, Ph.D., School of Environmental
Studies, Jadavpur University, Kolkata- 700 032, India, Tel: 91 33 4735233, Fax: 91
33 4734266, E-mail: dcsoesju@vsnl.com




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




  ARSENIC CONTAMINATION IN GROUNDWATER AND DRINKING
   WATER OF THE RED RIVER DELTA, VIETNAM – A PLEA FOR
               EARLY MITIGATION ACTIONS

Michael Berg, Roland Schertenleib, Walter Giger, EAWAG Switzerland; Hong
Con Tran, Thi Chuyen Nguyen, Hung Viet Pham, Hanoi University of Science

     Arsenic contaminated aquifers were discovered in late 1998 in the Red River
Delta of northern Vietnam through a cooperative project between Vietnam and
Switzerland aiming at building environmental sciences capacity in Vietnam. A
comprehensive survey on arsenic in ground and drinking water of the city of Hanoi,
and of the surrounding rural districts was conducted in 1999 and 2000.
      The study revealed arsenic concentrations in the groundwaters ranging from
1–3050 :g/L. Groundwater pumped through family-based tubewells contained a total
average of 159 :g/L arsenic. While 48% of the samples were above the Vietnamese
guideline value of 50 :g/L, an alarming fraction of 20% were even above 150 :g/L.
The tap water of Hanoi city, piped by the Hanoi water works, was less contaminated
(25–91 :g/L). The situation in the Red River Delta will be presented and discussed
considering the hydrogeological properties of both, natural and anthropogenic
influences.
       Our results indicate that several million people in the Red River Delta are at a
considerable risk of chronic arsenic poisoning. Interestingly, arsenic related health
symptoms have not been reported in Vietnam so far. We attribute this fact to the local
water use habits and the relatively short time of exposure of the people. The first
tubewells exploiting groundwater for direct consumption have been installed in the
last 6-8 years. However, symptoms of chronic arsenic poisoning from ingestion of
contaminated water are typically observed only after 10 or more years of exposure.
     To reduce the risk of chronic arsenic poisoning for people in Vietnam, we
urgently propose early mitigation actions and further evaluation of the extent of the
ground and drinking water contamination by arsenic in the alluvial deltas of Vietnam.

CORRESPONDING AUTHOR: Michael Berg, Water Resources and Drinking
Water Dept, Swiss Federal Institute for Environmental Science and Technology
(EAWAG), CH-8600 Duebendorf, Switzerland.
michael.berg@eawag.ch, www.eawag.ch/~berg/arsenic, www.eawag.ch/arsenic




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




         GROUNDWATER ARSENIC CONTAMINATION IN NEPAL:
           A NEW CHALLENGE FOR WATER SUPPLY SECTOR


Roshan R. Shrestha, Ph.D., Arinita Maskey B.Sc., Environment & Public Health
Organization (ENPHO) and Padam K. Khadka MA., Nepal Red Cross Society


Groundwater is the major drinking water source for the Terai population of southern Nepal
where 47% of total population of 23 million people lives. About 200,000 shallow tube-
wells are installed in the 20 districts that comprise the Terai region serving about 11
million people. Recently, arsenic contamination of the shallow groundwater aquifer has
become a big issue in Nepal., although it is not as severe as in Bangladesh and West
Bengal. To date, water samples from about 13,000 tube-wells have been tested with 29%
of samples exceeding the World Health Organization guideline of 10 ppb and 5% of
samples exceeding the “Nepal Interim Arsenic Guideline” of 50 ppb. This gives an
estimate of around 0.5 million people exposed to arsenic levels in drinking water above
50 ppb. Some recent studies have reported on the accumulation of arsenic in the human
body above toxic levels in arsenic-exposed areas. Government, national and international
non-governmental organizations are well aware of the situation now, but to date, the
government has not yet able to come up with concrete mitigation plans. Nepal still needs
more research work on arsenic occurrence and affects and, at the same time, a mitigation
program should be conducted in parallel. This paper highlights the details of the arsenic
studies conducted thus far by different agencies and the pros and cons of the current
measures to mitigate the arsenic problem in Nepal.


CORRESPONDING AUTHOR: Roshan R. Shrestha Ph.D., Environment & Public Health
Organization (ENPHO). P.O.Box 4102 Kathmandu Nepal. Fax : 977 1 491376. Email :
rshrestha@mos.com.np




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




 ENVIRONMENTAL IMPACTS, EXPOSURE ASSESSMENT AND HEALTH
  EFFECTS RELATED TO ARSENIC EMISSIONS FROM A COAL-FIRED
   POWER PLANT IN CENTRAL SLOVAKIA; THE EXPASCAN STUDY.

Thornton I., Farago M.E., Keegan T, Nieuwenhuijsen M. J., Pesch B., and the
EXPASCAN study group.

The coal-fired power plant at Novaky in the Prievidza district of Central Slovakia has
emitted in excess of 3,000 tonnes As since commencing operations in the 1950’s. This
resulted from the combustion of brown coal containing up to 1500:g/g As. Pollution
control measures reduced emissions from around 200-2 tonnes per year in the 1980’s. This
paper presents a) the results of environmental monitoring undertaken in 1999-2000, based
on the analysis of soils and dusts from 550 households comprising a population- based
case-control study of non-melanoma skin cancer, b) data on As levels in coal currently
used for power generation and in fly ash dumped within the district, c) estimates of As
exposure in the population in relation to distance from the plant, and d) a summary of
health statistics.

Although arsenic levels in soils and house dusts fell with distance from the plant, actual
concentrations were low with soils averaging around 40:g/g within 5km and 20-25:g/g
over 5km from the plant, and dusts 18 and 11:g/g As respectively. Total urine arsenic
concentrations were low, averaging 6.4mg/g creatinine and showed a weak correlation
with soil arsenic.

Predictions of As deposition rates from air dispersion modelling (ADMS) based on current
and historical levels of air borne As indicated soil As concentrations considerably in excess
of current levels. Possible losses due to leaching and biogeochemical cycling are
discussed together with the implications of these losses to human exposure.

Exposure to environmental arsenic in the study area was associated with an increased risk
of non-melanoma skin cancer, as was distance to the source of the arsenic. Exposure to
arsenic via locally grown food was associated, but not significantly, with increased risk
of non-melanoma skin cancer.

Arsenic emissions were highest 20 years ago and current environmental levels might not
reflect past exposure. The epidemiological exposure model included historical emissions
data but past and present industrial emissions from other sources and lack of accurate
exposure assessment of arsenic in the local diet could have confounded the distance- and
food-related exposure variables.




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




       ASSESSING POTENTIAL ARSENIC EXPOSURE PATHWAYS IN
                         BANGLADESH

Ravi Naidu1, Imamul Huq2, Euan Smith1, Ray Correll3, Lester Smith1, Julie Smith1,
Tapas Biswas1, the late Mushtaq Ahmed2, the late Shibtosh Roy4 and Mary Barnes3
1
  CSIRO Land and Water, Waite Road, Urrbrae, Adelaide SA 5064,
2
  Department of Soil Science, Dhaka University, Dhaka, Bangladesh
3
  CSIRO Mathematical and Information Sciences, Waite Road, Urrbrae, Adelaide, SA
5064
4
  Dhaka Community Hospital, Dhaka, Bangladesh

Background

Since the first report on possible arsenic (As) poisoning of people in the Indian
subcontinent, many incidences of chronic As toxicity has been identified in a number of
countries in the SE Asia region. Almost all of these cases have been related to the
ingestion of As-contaminated groundwater. The As concentrations in groundwater
exceed the Bangladesh recommended value of 0.05 mg L-1 in 52 of the 64 districts in
Bangladesh and 560 villages in West Bengal, India. (Note that the WHO standard is
0.01 mg L-1 ). Given the lack of detailed studies on possible pathways of As exposure,
it has been assumed that poisoning is through the consumption of water per se.
However, the chronic As toxicity symptoms recorded indicate that the exposure to As
may involve a number of pathways. Arsenic contaminated groundwater is used for
irrigation as well as for cooking and it is likely that the last 30 years of irrigation have
led to diffuse contamination of land throughout the districts relying on As contaminated
groundwater. This indicates that soil-crop-food transfer, as well as cooking and direct
ingestion of drinking water may be the major exposure pathways of As transfer. This
paper explores several pathways of inadvertent exposure including ingestion of food.
Future studies are planned to investigate As exposure through ingestion of dust and soil
and dermal absorption, especially in the Asian region where wetland farming is a major
activity amongst the farming community. Only data on As content of food crops are
presented here.




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




   CHILDREN’S EXPOSURE TO ARSENIC IN CHROMATED COPPER
 ARSENATE (CCA)-TREATED WOOD AND CCA-CONTAMINATED SOIL

   Tim F. McMahon, Ph.D., Doreen Aviado, B.S., Winston Dang, Ph.D., Siroos
Mostaghimi, Ph.D., Jonathan Chen, Ph.D. U.S. Environmental Protection Agency,
Office of Pesticide Programs, Washington D.C.

   The Office of Pesticide Programs (OPP) is aware of increased concerns by the
public regarding the safety of CCA-treated wood and children’s exposure to the
arsenic component of this wood. Therefore, an exposure assessment is currently
being conducted by the Antimicrobials Division (AD), OPP, to determine potential
non-dietary exposures of children that may occur from contact with CCA-treated
wood playground structures and CCA-contaminated soils. Dermal and oral exposure
may occur from contact with dislodgeable surface residues of arsenic as well as with
contaminated soil. As part of the development of this assessment, specific exposure
data issues were presented by AD scientists to the FIFRA Scientific Advisory Panel
(SAP) in October of 2001 for discussion. The SAP provided recommendations to
AD in several areas of the exposure assessment. The most significant of these was
the recommendation to use probabilistic exposure modeling for assessment of
children’s exposures. AD is now in the process of implementing this approach to
assessment of children’s exposure to arsenic from CCA-treated wood, and hopes to
use the results of this approach, when available, in the risk assessment for CCA-
treated wood.


CORRESPONDING AUTHOR: Tim F. McMahon, Ph.D. , U.S. Environmental
Protection Agency, Office of Pesticide Programs, 1200 Pennsylvania Ave. N.W.,
Ariel Rios Building, Mail Code 7510C, Washington, D.C. 20460




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




 TRIVALENT ARSENIC COMPOUNDS: SPECIATION, PRESERVATION,
             AND INTERACTION WITH PROTEINS

X. Chris Le, Ph.D., Zhilong Gong, Ph.D., Guifeng Jiang, Ph.D., Xiufen Lu, M.Sc.,
University of Alberta
William R. Cullen, Ph.D., University of British Columbia

         Trivalent arsenic compounds, including arsenite (AsIII), monomethylarsonous
acid (MMAIII), and dimethylarsinous acid (DMAIII), are now known to be more toxic
than their pentavalent counterparts, namely arsenate (AsV), monomethylarsonic acid
(MMAV), and dimethylarsinic acid (DMAV). We describe the speciation analysis of
these trivalent arsenic compounds in biological systems and examination of
interactions between trivalent arsenic species with proteins.
         The speciation analysis of arsenic was carried out by using high performance
liquid chromatography (HPLC) separation with hydride generation atomic
fluorescence detection (HGAFS). MMAIII and DMAIII were found to be unstable in
urine samples and therefore a method for preserving these arsenic species was
developed. Several complexing agents were tested as additives to preserve MMAIII
and DMAIII in human urine samples. Diethylammonium diethyldithiocarbamate
(DDDC) was found to be most suitable for this purpose.
         Both inductively coupled plasma mass spectrometry (ICPMS) and
electrospray quadrupole time-of-flight mass spectrometry (Q-TOF MS) were used to
study the binding between a model protein metallothionein and various arsenic
compounds. Size exclusion chromatography with ICPMS analysis of reaction
mixtures between trivalent arsenic compounds and metallothionein demonstrated the
formation of complexes of arsenic with metallothionein. Analysis of the complexes
using Q-TOF tandem mass spectrometry revealed the detailed binding stoichiometry
between arsenic and the 20 thiol groups in the metallothionein molecule. AsIII and two
methylation metabolites, MMAIII and DMAIII, showed different binding stoichiometry
with the metallothionein. Each metallothionein molecule could bind with up to 6
AsIII, 10 MMAIII, and 20 DMAIII molecules, consistent with the available binding sites
on these arsenicals. Tandem mass spectrometry detection of the fragment ions from
the intact protein provided further evidence for the As-S bond formation in the
arsenic-metallothionein complex.


CORRESPONDING AUTHOR: X. Chris Le, Ph.D., Department of Public Health Sciences, Faculty of
Medicine, University of Alberta, 10-102 CSB, Edmonton, Alberta, Canada T6G 2G3




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




  ARSENIC SPECIATION IN PROBLEMATIC SEAFOOD MATRICES:
   THE IMPORTANCE OF A SPECIES SPECIFIC MASS BALANCE

John T. Creed, Ph.D., Patricia A. Gallagher, Ph.D., Jody Shoemaker, Ph.D.,
Carol A., Schwegel, US EPA; Bryan M. Gamble, Ph.D., Amy N. Parks, Oakridge
Research Fellows

         Arsenic has two major exposure routes: dietary and drinking water
ingestion. Dietary exposures can easily exceed those typically associated with
drinking water but the risk associated with these exposures are strongly influenced
by the toxicity of the arsenicals present in the sample. For instance, a major
source of dietary arsenic is seafood but 90+% of the “extractable” arsenicals can
be non-toxic; therefore, species specific information is essential in estimating the
risk associated with dietary exposures. A source of uncertainty associated with
estimating dietary risks is the limited availability of species specific data on target
foods.
        One of the analytical problems associated with arsenic speciation (species
specific detection) in dietary samples is the need to extract the arsenicals from the
solid dietary matrix. In many cases, the predominant “extractable” arsenical
associated with seafood has been non-toxic arsenobetaine, but in certain seafood
matrices the “extractable” arsenicals may be less than 50% of the total arsenic.
This raises questions about the toxicity of the “unextractable” arsenicals and the
potential for underestimating the risk (i.e., exposure) based on this analytical
extraction bias. These low extraction efficiencies can be further complicated by
unchromatographable arsenicals. The net result is the unextractable and
unchromatographable fraction sequentially decrease the available speciation
information.
        This presentation will focus on the use of tetramethylammonium
hydroxide as an extraction solvent in seafood samples collected in the Pacific
Northwest (clams, mussels, and oysters). This presentation will address the
conversion of unchromatographable species to chromatographable arsenosugars
and how this influences the overall speciation recovery and in turn the ability to
assess the risk from these matices.

CORRESPONDING AUTHOR: John T. Creed, Ph.D., US EPA, Mail Stop 564,
26 W. Martin Luther King Drive, Cincinnati, OH 45268, USA.




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




                  ARSENIC IN YELLOWKNIFE, CANADA

William. R. Cullen, Ph.D., Lixia Wang, B.Sc., Vivian W.-M. Lai, M.Sc., Elena
Polishchuk, Ph.D., Environmental Chemistry Group, University of British Columbia;
Iris Koch, Ph.D., Christopher A. Ollson, M.Sc., Kenneth J. Reimer, Ph.D.,
Environmental Sciences Group, Royal Military College of Canada

        The arsenic levels in soil from the City of Yellowknife, Canada, range from
4 ppm to 148 ppm and at some mine sites from 2125 ppm to 87,000 ppm. In such
an arsenic rich environment there are problems in determining what are the natural,
pre-mining, concentrations that could be considered to be a remediation objective.
We have applied principal component analysis (PCA) to this problem and conclude
that the background arsenic concentrations are in the range 3 ppm to 150 ppm with
an average value of 42 ppm, far higher that the Canadian guideline of 12 ppm.
        About 260,000 tones of arsenic trioxide (ca. 80% pure) are stored
underground in old mine workings and in specially constructed vaults. The options
for safe management of this material will be discussed. Some promising results are
being obtained from mine-dust/bitumen materials. Many fungi such as Aleurodiscus
farlowii grow underground: these are being isolated and identified by using 28S
RNA analysis. We are studying how they prosper in such an arsenic–rich
environment. Sequential extraction and gastric fluid models are being developed to
determine the bioavailability of arsenic from local soils, vegetables, and country
food.

CORRESPONDING AUTHOR: William R. Cullen, Ph.D., Environmental
Chemistry Group, Chemistry Department, University of British Columbia,
Vancouver, B. C., Canada, V6T 1Z1.




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




           POTENTIAL FOR ADVERSE EFFECTS OF SOIL AS

Rufus L. Chaney, USDA-ARS, Animal Manure and Byproducts Lab, Bldg. 007,
BARC-West, Beltsville, MD. 20705-2350. USA.
    As is a natural constituent of soils and plants. The low soil As limit suggested
by some (3.0 mg As/kg soil) is below natural background levels in US soils; thus
validity of such limits is being questioned. Background As levels in US soils are
5-10 mg/kg, with range exceeding 20 mg/kg for acid sulfate soils; background As
exceeds suggested soil As limits. Extensive contamination of soils with As by
historic agricultural uses (orchard, cotton, and potato soils; tick treatment soils),
mining, smelting, and the extensive use of Cr-Cu-As-treated lumber, indicate that
over 50% of US surface soils would need to be replaced. It seems irrational to
conclude that median background soils are causing human As risk thru soil
ingestion.
    Rice accumulates As well compared to most plant foods. Rice accumulation
of As from soils irrigated with As-rich water over decades was not increased in
either As-sensitive or -resistant rice cultivars in a collaborative field test in
Bulgaria indicating lower potential food-chain As risk than some suggest.
    Soil ingestion comprises greater risk than eating garden foods. The
assumptions in soil As risk assessment are known to be faulty; one assumes that
children consume soil at the rate of a 2-year-old child for one’s lifetime;
adjustment of risk estimates is needed for short term exposure of children by soil
ingestion. Raised urinary As in children exposed to As in soil and dust found that
soil As had to exceed 40-100 mg As/kg before there was a significant increase in
urinary As from inorganic sources, suggesting that soil As would have to exceed
this level before any increase in absorbed As would occur.




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




    ARSENIC MOBILIZATION IN BANGLADESH GROUNDWATER

Y. Zheng, Ph.D., R. K. Dhar, Queens College and Lamont-Doherty Earth
Observatory of Columbia University, M. Stute, Ph.D., A. van Geen Ph.D., A.
Horneman, LDEO, I. Gavrieli, Ph.D., Israeli Geological Survey, S. Goodbred,
Ph.D., Stony Brook University, R. Versteeg, Ph.D., M. Steckler, Ph.D., H. J.
Simpson, Ph.D., Z. Cheng, Ph.D., LDEO, K. M. Ahmed, Ph.D., M.
Shamsudduha, and M. Shahnewaz, Dhaka University.

    In the Ganges-Brahmaputra Delta, concentrations of arsenic in groundwater can
vary from < 5 mg/L to > 1000 mg/L within lateral and vertical scales of tens of
meters. The main objectives of our study are to understand the factors that contribute
to such spatial variability of arsenic at the local scale (# 1 km) and to investigate any
potential temporal variability of groundwater arsenic concentrations in order to
illustrate the origin of As.
    Multi-disciplinary investigation to date has focused on several villages within a
20-km2 region in Araihazar Upazila, about 20 km east of Dhaka. Extreme spatial
variability of arsenic concentrations (< 5 to ~ 800 mg/L) is observed in the shallow,
presumed Holocene sedimentary aquifers. A suite of redox-indicators measured in
parallel with arsenic indicate that As mobilization generally follows the reduction of
Fe-oxyhyroxides, and, in some cases, even extends into sulfate-reducing state.
Drilling at several locations identified clay formations of various thickness at various
depth interval that separates the shallow, As-containing aquifer from the deep, low
As aquifer that is chemically distinct. Despite the extensive spatial variability, we
observed little temporal variability of arsenic concentrations in both the shallow and
the deep aquifers. Only one of ~ 50 shallow groundwater wells (< 50 ft) in a village
that were sampled in March-June 2001, January, June and September 2001 showed
a difference of As concentration greater than the analytical uncertainty. Monitoring
wells installed at various depths were sampled at monthly interval and showed little
variation of arsenic concentrations throughout 2001.

CORRESPONDING AUTHOR: Yan Zheng, Ph.D., Queens College, City
University of New York, Flushing, NY 11367 and Lamont-Doherty Earth
Observatory of Columbia University, Palisades, NY 10964.




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      5TH International Conference on Arsenic Exposure and Health Effects
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     A LONG-TERM FOLLOW-UP STUDY ON DOSE-RESPONSE
    RELATIONSHIP BETWEEN INGESTED ARSENIC AND MAJOR
        CANCERS AND VASCULAR DISEASES IN TAIWAN

Chien-Jen Chen, Sc.D., Chi-Ling Chen, Ph.D., Chih-Hao Wang, M.D., Lin-I Hsu,
Ph.D., Chin-Hsiao Tseng, Ph.D., National Taiwan University; Hung-Yi Chiou,
Ph.D., Yu-Mei Hsueh, Ph.D., Taipei Medical University; Shu-Yuan Chen, Ph.D.,
National Health Research Institutes; Meei-Mann Wu, Ph.D., Academia Sinica

     We have recently documented the biological gradient between ingested arsenic
and risk of various cancers, peripheral vascular disease, ischemic heart disease,
cerebral infarction, microcirculation retardation, diabetes mellitus and hypertension
through ecological, cross-sectional or case-control studies. The specific aim of this
study is to follow-up three cohorts of study subjects in arseniasis-endemic and non-
endemic areas to compare their risk of major cancers and vascular diseases. The first
cohort included 2,905 residents in the southwestern arseniasis-endemic area recruited
from1984 to 1992. The second cohort included 8,102 residents in the northeastern
arseniasis-endemic area recruited from 1994 to 1996. The third cohort included
23,943 resident in seven non-arseniasis-endemic townships recruited from 1991 to
1992. History of exposures to ingested arsenic and various risk factors was obtained
through standardized questionnaire interview. The occurrence of major cancers and
vascular diseases of cohort members was ascertained by home visit/telephone
interview and double-check with medical chart review and by data linkage with
National Death Certification and National Cancer Registry profiles. Cox
proportional hazards regression analysis was used to assess the relative risk of
developing major diseases and its 95% confidence interval for each risk factor.
Residents in arseniasis-endemic areas had a significantly higher risk of major cancers
and vascular diseases than residents in non-endemic areas. There was a significant
dose-response relationship between major cancers and vascular diseases and ingested
arsenic at levels ranging from <10 to >700:g/L, with a clearly increased risk at the
level of 10-50:g/L.

CORRESPONDING AUTHOR: Chien-Jen Chen, Sc.D., Graduate Institute of
Epidemiology, College of Public Health, National Taiwan University, 1 Jen-Ai Road
Section 1, Taipei 10018, TAIWAN.




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       EXPOSURE TO ARSENIC IN DRINKING WATER DURING
                       PREGNANCY

Claudia Hopenhayn, M.P.H., Ph.D., Bin Huang, M.S., Steven R. Browning, Ph.D.,
Cecilia Peralta, University of Kentucky, USA; Catterina Ferreccio, M.D., M.P.H.,
Pontificia Universidad Católica de Chile; Irva Hertz-Picciotto, M.P.H., Ph.D.,
University of California, Davis, USA; Herman Gibb, Ph.D., Environmental
Protection Agency, USA; Jose Centeno, Ph.D., American Registry of Pathology,
Armed Forces Institute of Pathology, U.S.A.

        The current evidence indicates that arsenic increases the risk of various
cancers, and is also associated with non-cancer health effects such as diabetes,
hypertension and other cardiovascular events. Although limited, the existing
evidence also suggests that arsenic may have adverse reproductive effects in humans.
The purpose of this study is to investigate pregnancy and birth outcomes in relation
to arsenic exposure from drinking water.
        We conducted a prospective cohort study, enrolling pregnant women in two
Chilean cities: 454 in Antofagasta (arsenic water level of 40 ug/L), and 468 in
Valparaíso (As level <1 ug/L). Study subjects completed in-depth interviews,
providing information on demographics characteristics, medical and reproductive
history, diet, fluid intake, lifestyle habits, and other factors. We obtained pregnancy
and birth related data from prenatal and hospital records. All births took place from
12/29/98 to 3/19/00. Biological samples including urine, placenta and cord blood
were obtained for different sub-groups of the cohort. We also used the Perinatal
Information System (SIP) from the Pan-American Health Organization to collect a
detailed database of all births occurring at each city’s main hospital, from July, 1999
to July, 2000, totaling over 8,000 births.
        We will present the overall results of the study, focusing the analysis on
birthweight from both the cohort and the SIP data, which show consistent and similar
results, with an overall decrease in mean birthweight of about 50 grams in the
arsenic-exposed city after controlling for relevant covariates. We will also present
results of the analysis of biological samples, currently being completed.

Corresponding author: Claudia Hopenhayn, M.P.H., Ph.D., Department of Preventive
Medicine and Environmental Health, University of Kentucky, 1141 Red Mile Road,
Suite 201, Lexington, KY 40504.




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          CRITERIA FOR CASE DEFINITION OF ARSENICOSIS

                         DN Guha Mazumder, MD., FAMS

     Institute of Post Graduate Medical Education & Research, Kolkata, India

In spite of availability of large number of publications based on studies on health
aspect of chronic As toxicity, no standard definition is available to characterize fully
the clinical effects of chronic As exposure in man. Only small number of reports are
based on validation of diagnosis on proper As exposure data, blinding of cases and
controls, total assessment of clinical effect, and correlation of these effects with As
level in water, and various biomarkers. It was therefore felt necessary to prepare a
clinical case definition of chronic arsenicosis.

Thirty six papers on As related health effects were reviewed directly and numerous
cross references consulted. Giving weightage on the quality of these papers,
diagnostic criteria of chronic arsenicosis have been prepared.

On the basis of review of literature, a minimum period of six months of ingestion of
As have been considered for the diagnosis of arsenicosis. Normal As values of urine,
hair and nails determined by proper techniques, e.g. AAS or NAA have also been
reviewed. Mean +2SD of the normal values of the acceptable published reports have
been calculated. From these the upper limit of normal As level in urine, hair and nail
was considered to be as 0.05 mg/l, 0.8 mg/kg and 1.3 mg/kg, respectively.

Skin lesions, simulating arsenical dermatosis, but caused by other systemic or skin
diseases simulating As induced skin lesion have been reviewed. These conditions
need to be considered in the differential diagnosis of arsenicosis. Over and above
skin lesions, criteria related to systemic manifestation and various As related cancers
were also considered for the preparation of case definition of chronic Arsenicosis. A
simplified algorithm of case definition, using dermatological criteria as major clinical
diagnostic parameter, has been prepared and will be presented in the conference.

Corresponding Author : Dr. DN Guha Mazumder, Instt. Post. Grad. Med. Edu. &
Res., 244, AJC Bose Road, Kolkata – 700 020. India. Email- dngm@apexmail.com




                                          32
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




 A COHORT STUDY OF HEALTH EFFECTS OF ARSENIC EXPOSURE
   IN BANGLADESH: PROGRESS AND PRELIMINARY FINDINGS

Habibul Ahsan, M.D., M.Med.Sc., Faruque Parvez, M.P.H., Columbia University;
A.Z.M. Iftikhar Hussain, M.B.B.S., M.P.H., Hassina Momotaj, M.B.B.S., M.P.H.,
National Institute of Social and Preventive Medicine (NIPSOM); Yu Chen,
M.P.H., Geoffrey Howe, Ph.D., Wei-Yan Tsai, Ph.D., Regina Santella, Ph.D.,
Paul Brandt-Rauf, M.D., Ph.D., Jack Longley, M.D., Alexander van-Geen, Ph.D.,
and Joseph Graziano, Ph.D., Columbia University.

        We are conducting a large epidemiologic cohort study of 10,000 men and
women to comprehensively examine prospectively the health effects of arsenic
exposure in Bangladesh with an initial emphasis on the full dose-response
relationships of arsenic exposure with the incidence rates of skin lesions, skin
cancers, and total and cancer-related mortalities. In addition, using cross-sectional
and case-cohort designs within the main cohort, the interrelationships among
urinary arsenic metabolites, a number of biomarkers and health outcomes are also
being examined.
       To build a sampling frame for the cohort study, 6,000 tube-wells in a
contiguous area were surveyed and analyzed enumerating and characterizing
60,000 residents. Using predetermined sampling criteria, 10,000 men and women
(from the 60,000 residents) were recruited in the cohort. Extensive interview,
clinical data, and biological samples have been collected from the cohort
members. The cohort members are being actively followed to ascertain the study
outcomes. Overall, data from this comprehensive study will provide information
on the interrelationships between arsenic doses, intermediate biomarkers, and
other host and lifestyle factors including the genetics and nutrition in the etiology
of arsenic-induced cancers and other health outcomes. Design and progress of
this comprehensive epidemiologic study, preliminary baseline data, and a
preliminary analysis of cancer burden in Bangladesh based on the baseline data
will be presented.


CORRESPONDING AUTHOR: Habibul Ahsan, M.D., Med.Sc.,
Department of Epidemiology, Columbia University, 600 West 168th Street,
PH 18, New York, NY 10032




                                         33
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




  RELATIONS OF URINARY TRIVALENT METHYLATED ARSENIC
SPECIES WITH ARSENIC-SKIN LESIONS AND URINE CYTOLOGY IN
POPULATION CHRONICALLY EXPOSED TO INORGANIC ARSENIC.

Olga L. Valenzuela BSc, Luz M Del Razo Ph D Toxicology Section,
CINVESTAV-IPN, México. Jesús Aguirre BSc, Hospital General de México,
Martha B Cruz BSc, Diana Lechuga MSc. and Betzabet Calderon BSc,
Secretaria de Salud de Hidalgo, México.

        Biomethylation is the major metabolic process for inorganic As in humans.
Inorganic As undergoes metabolic conversion that include reduction of pentavalent
arsenicals to trivalency and oxidative methylation of trivalent species that yields to
methylarsenic (MAs) and dimethylarsenic (DMAs) species. Thus, both pentavalent
and trivalent arsenicals are intermediates or final products of this pathway that can
be found in human urine. Due to increased recognition of the role of methylated
arsenicals that contain AsIII in the toxicity and metabolism of As, our objective was
to study the relationship of trivalent methylated metabolites with toxicity signs in
humans chronically exposed to As.
        Some habitants of Zimapan area located in Hidalgo state, Mexico (about 220
km north-east of Mexico City), have been exposed to very high levels of arsenic (As)
in drinking water (150 to 1,350 ppb) at least from 1993. The highest ground water
As concentrations appear to come from dissolution of the As bearing rocks. In
Zimapan area, many people present characteristic skin lesions related with chronic
As exposure, such as keratosis, hyperpigmentation and hypopigmentation.
        A group of 104 exposed residents from endemic As-area of Zimapan were
asked to answer a questionnaire and allow to be physically examined. 51 participants
displayed severe skin injuries, 24 presented discreet dermal injuries and 29 did not
presented skin lesions. Collected spot urine samples were frozen in dry ice and
trivalent As species were analyzed approximately four hrs after collection,
additionally exfoliated bladder cells were obtain from urine samples for cytology
analysis. Trivalent methylated arsenic species were present in almost all the urine
samples (96 %), being DMAIII the major trivalent metabolite. The relationship
between trivalent arsenic species in urine and frequency of transformed epithelial
bladder cells will be investigate.
        Characterization of the urinary excretion of arsenicals that contain AsIII may
provide a new biomarker of the effects of chronic exposure to As.
Supported by Conacyt-Mexico 38471-M


CORRESPONDING AUTHOR: Luz M. Del Razo, Ph.D. Toxicologia,
CINVESTAV-IPN, P.O.Box 14-740, Mexico D.F., email:
ldelrazo@mail.cinvestav.mx




                                         35
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




THE DISTRIBUTION OF ARSENIC CONCENTRATION IN WATER OF
          CHINA AND THE RELATION TO PATIENTS


Guifan Sun, Ph.D., China Medical University; Yang Hao, Ph.D., Division of
Endemic and Parasitic Diseases Control, Department of Diseases Control,
Ministry of Health, China; Quanmei Zheng, Prof., China Medical University;
Jihong Yin, Prof., Renmin University of China; Hiroshi Yamauchi, Ph.D., School
of Medicine, St. Marianna University, Japan


    From 2001, we had been carrying out a nationwide survey of arsenicosis in
China. Besides the known epidemic areas, i.e. Xinjiang, Inner Mongolia, Shanxi
and Guizhou, new areas have been found in Jinlin, Ningxia and Qinghai
provinces. In order to obtain further information about the distribution of arsenic
concentration in water of China, two severe epidemic areas, i.e. Shanxi province
and Inner Mongolia were selected as the investigation bases. Arsenic
concentration in water were measured by field-test kit purchased from Merk
Company of Germany. Epidemiological investigations were carried out
meanwhile.
    35 villages of Shanxi province were investigated. 1612 out of total 3079 wells
were unsafe (arsenic concentration was above 0.05mg/L), with the ratio of 52 per
cent. Among the 9656 examined persons, 1561 were found to be patients. The
examination rate and prevalence rate among the examined persons were 53 and 16
per cent, respectively. 5885 wells of 64 villages were detected in Inner Mongolia.
Wells of arsenic concentration between 0.05~0.1, 0.1~0.5, and above 0.5mg/L
were 396, 267 and 2, respectively. 665 out of total 5885 wells were unsafe, with
the ratio of 11 per cent.
    The investigation base of Shanxi was selected from the areas that had not
undertaken water mitigation, and occupied only a very small fraction compared
with the capacious epidemic areas. Therefore, large-scale investigation should be
needed so as to find new areas. As regard Inner Mongolia, the base was selected
from near the known epidemic areas, and was not officially considered to be areas
of arsenicosis. It can be concluded that the epidemic areas tend to expand
gradually now. Water samples are detected for the concentration of fluoride and
iodin in lab now.




                                        36
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




 RISK ANALYSIS OF NON-MELANOMA SKIN CANCER INCIDENCE
            IN ARSENIC EXPOSED POPULATION

Vladimír Bencko, M.D., Ph.D., JiÍí Rameš, D.Sc., Charles University of Prague,
Czech Republic; Miloslav Götzl, M.D., Department of Oncology District Hospital
of Bojnice, Slovak Republic; Petr Frank, EuroMISE Centre, Charles University
of Prague & Czech Academy of Sciences, Czech Republic; Marián Jakubis, State
Institute of Health, Prievidza, Slovak Republic

         The subject of our analysis was a database of 1024 nonmelanoma skin
cancer cases collected within 20 years (4 five year intervals) in a region polluted
by emissions from burning of coal with high arsenic content ranging between 900
to 1,500 g per metric ton of dry coal. The standardized incidence of nonmelanoma
skin cancer (each confirmed by biopsy or autopsy histological examination) in a
district with population ~125,000 in non-occupational settings ranged from 45.9
to 93.9 in men and from 34.6 to 81.4 in women per 100,000 (study base 1,328
thousands man/year and 1,334 thousands woman/year) while relevant data for
occupational settings (male workers of power plant burning arsenic reach coal)
ranged from 44.6 to 10 317 per 100,000 (study base 27 thousands man/year).
Smoking habit was carefully registered in all cancer patients including non-
melanoma skin cancer cases and potential contribution of the both factors was
analyzed. Exposure assessment was based on biological monitoring.
Determination of arsenic was done in groups of 10 year old boys (in non –
occupational settings) by analyzing of hair and urine samples at different localities
situated up to the distances of 30 km from the local power plant.
         Analysis of our database demonstrates a positive correlation of human
cumulative arsenic exposure and incidence of non-melanoma skin cancer.

Key words: cancer epidemiology, biological monitoring, arsenic toxicity, and non-
melanoma skin cancer incidence
     Acknowledgement: The presented data resulted from EC supported INCO
COPERNICUS EXPASCAN project .

CORRESPONDING AUTHOR: Prof. Vladimír Bencko, M.D., Ph.D., Institute of
Hygiene & Epidemiology, First School of Medicine, Charles University of Prague,
Studni…kova 7, CZ 128 00 Praha 2, Czech Republic.




                                         37
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




                          U.S. Arsenic Exposure Data


Floyd J. Frost, Ph.D.
Center for Pharmacoeconomic and Outcomes Research
Lovelace Respiratory Research Institute
2425 Ridgecrest Dr. SE
Albuquerque, NM 87108



This report summarizes the completeness and accuracy of drinking water arsenic
occurrence data in the United States and to identify arsenic-exposed populations
suitable for epidemiological studies of arsenic health effects. Using data from the
U.S. E.P.A. Arsenic Occurrence and Exposure Database, data we obtained from
state health or environment departments, and data we obtained directly from water
utilities, we identified 33 counties in 11 states with a mean drinking water arsenic
concentration greater that 10 parts per billion (ppb). Eleven counties had a mean
arsenic concentration greater than 20 ppb, and 2 counties had a mean arsenic
concentrations greater than 50 ppb. Between 1950 and 1999 there were 51
million person-years of exposure to drinking water with more than 10 ppb arsenic,
8.2 million to more than 20 ppb arsenic and 0.9 million to more than 50 ppb
arsenic. Death rates in these counties from potentially arsenic-related causes
should be examined as part of a comprehensive assessment of arsenic health
effects in U.S. populations.




                                        38
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




EXAMINATION OF THE NRC BLADDER CANCER RISK FROM ARSENIC IN
    DRINKING WATER ESTIMATE, USING US DATA WITH 75 MILLION
                      PERSON-YEARS OF OBSERVATION
Steven H. Lamm, Arnold Engel, Richard Wilson, and Manning Feinleib
Consultants in Epidemiology and Occupational Health, Inc.
Harvard University Department of Physics
Johns Hopkins School of Public Health

      The NRC (2000) estimate for bladder cancer risk from arsenic in drinking water is
based on the data from the Blackfoot Disease Endemic area of SW Taiwan where increased
risks of bladder cancer mortality were found in villages with 400 (+) ug/l arsenic in their
drinking water. Those data have been adjusted and analyzed in order to predict the arsenic
in drinking water bladder cancer risk in the United States where drinking water arsenic
levels may go as high as 50 ug/l but are generally in the 3-12 ug/l or lower range. We now
present US data on bladder cancer mortality (1950-1979) in 133 US counties known to
depend on ground water as their drinking water source (per state departments of the
environment) and with ground water median arsenic concentrations of 3 ug/l or greater (US
Geological Survey). The bladder cancer mortality for these 133 US counties, which
includes a population of 2.5 million white males (1960 census), has been observed for 30
years (1950-1979) by the National Cancer Institute for a total observation of 75 million
person-years of observation.




Overall, the lifetime risk of bladder cancer mortality for white males is seen to be 0.005
(1/200) and no increase with increased level of arsenic in the drinking water is observed.
Linear regression shows a slope indistinguishable from zero, revealing no evidence of an
arsenic-dependent risk in this exposure range. The R-squared is 0.0002, and the slope
(lifetime increased risk per 1 ug/L arsenic exposure) is –4 E-06 with 95 % confidence limits
of –5 E-05 to+4.2 E-05. The NRC predicted risk of 4.6 E-05, based on extrapolation and
adjustment from the southwest Taiwan data, is outside of the range that is consistent with
the US experience shown here in the 75 million person-year study. New toxicological
studies provide explanations as to why the increased bladder cancer risk from certain
villages in SW Taiwan is not predictive of the US experience with arsenic in the drinking
water and bladder cancer mortality.

                                            39
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




ARSENIC CONCENTRATIONS IN WELL WATER AND RISK OF SKIN
        CANCER IN WISCONSIN’S FOX RIVER VALLEY


Lynda M. Knobeloch, Ph.D., Henry A. Anderson M.D., and Lawrence P.
Hanrahan, Ph.D. Wisconsin Department of Health and Family Services.

        In 1987, elevated arsenic levels were discovered in several private
drinking water wells located in Wisconsin’s Fox River Valley. A follow-up
investigation identified a large vein of arsenic-bearing mineral deposits at the
interface of the St. Peter Sandstone and Sinnipee Dolomite. This formation
stretches more than 100 miles and threatens more than 20,000 private water
supplies. Nearly 2,000 wells were sampled between 1992 and 1993.
Concentrations ranged from below detection to 12,000 :g/L, and exceeded the
new federal standard of 10 ug/L in 20 percent of the wells.
        Since June 2000, 18 townships in this area have sponsored voluntary water
testing programs for their residents. As part of these programs, water use and
health history questionnaires were distributed along with water collection kits to
families that participated in the arsenic testing. More than 2,000 families
completed these providing arsenic exposure and health outcome information for
nearly 7,000 individuals. Residents who ingested water that contained more than
5 ug of arsenic per liter for 10 years or longer were more likely to report a
diagnosis of skin cancer than others. Residents over the age of 64 years who
reported both a history of cigarette use and long-term exposure to arsenic-
contaminated water had the highest skin cancer rate.

CORRESPONDING AUTHOR: Lynda M. Knobeloch, Ph.D., Department of
Health and Family Services, 1 West Wilson St, Rm 150, Madison, WI 53701,
USA.




                                       40
         5TH International Conference on Arsenic Exposure and Health Effects
                                SPEAKERS ' ABSTRACTS




    HEALTH EFFECTS OF CHRONIC EXPOSURE TO ARSENIC VIA
   DRINKING WATER IN INNER MONGOLIA: I. BIOMARKERS FOR
             ASSESSING EXPOSURE AND EFFECTS

Judy L. Mumford, Ph.D., Mike Schmitt, M.S.P.H., Richard K. Kwok, M.S.P.H.,
Rebecca Calderon, Ph.D., National Health and Environmental Effects Research
Laboratory, U.S. Environmental Protection Agency; Yajuan Xia, M.D. Ke Kong
Wu, M.D., Inner Mongolia Center for Endemic Disease Control and Research,
Kuan Yang, Li He Anti-epidemic Station, X. Chris Le, University of Alberta,
Tong-cun Zhang, National Research Council

       The residents of Ba Men, Inner Mongolia have been exposed to high
concentrations of arsenic via drinking water and showed health effects. We
conducted studies to assess health effects of arsenic, including dermal, DNA and
chromosome damage, in Ba Men and to identify biomarkers useful for assessing
arsenic exposure and health effects. A total of 321 Ba Men residents, exposed to low
(<21 µg/L), medium (100-300 µg/L), or high (450-690 µg/L) concentrations of
arsenic were examined for the presence of skin hyperkeratosis, hyperpigmentation
or depigmentation. Samples of well water, toenail, and urine were collected and
analyzed for arsenic content. Buccal cells were collected and assayed for DNA
fragmentation (by TUNEL assay) and micronuclei to assess chromosome damage.
Results showed that skin hyperkeratosis and alterations in skin pigmentation were
highly associated with arsenic concentrations in water, nails and urine (p<0.001).
Increased micronucleus frequency and DNA fragmentation in buccal cells were
associated with arsenic concentrations in water and nails (p<0.01). In urine, the
percent of methylated arsenicals in relation to total urinary arsenic was decreased
(83% for low dose group to 79% for high dose group) as the arsenic concentration
in drinking water increased, suggesting limiting capacity for methylation in humans.
Nail arsenic was a better exposure biomarker than urinary arsenic for assessing
chronic health effects. This study showed that exposure to arsenic was associated
with dermal effects as well as DNA and chromosome damage. These biomarkers are
potentially useful in early detection of health effects from chronic exposure to
arsenic.

CORRESPONDING AUTHOR: Judy L. Mumford, Ph.D. Human Studies
Division, National Health and Environmental Effects Research Laboratory, U.S.
Environmental Protection Agency; Research Triangle Park, NC 27711, U.S.A.
(This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.)




                                                           42
        5TH International Conference on Arsenic Exposure and Health Effects
                               SPEAKERS ' ABSTRACTS




  HEALTH EFFECTS OF CHRONIC EXPOSURE TO ARSENIC IN
DRINKING WATER IN INNER MONGOLIA: II. VIBROTACTILE AND
                   VISUAL MEASURES

David Otto, Ph.D., Judy Mumford, Ph.D., Richard K. Kwok, M.S.P.H., Ken
Hudnell, Ph.D., U.S. Environmental Protection Agency; Yanhong Li, M.D.,
Yajuan Xia, M.D. and Kegong Wu, M.D., Inner Mongolia Center for Endemic
Disease Control and Research; Ling Ling He, B.S., BaMen Anti-epidemic Station,
Biaxiao Zhao, B.S., Lin He Anti-epidemic Station

        Exposure to arsenic via inhalation, oral or dermal pathways is known to
produce peri-pheral neuropathy in humans. A variety of neurotoxic symptoms
including auditory, visual and somatosensory were reported (Ma et al, 1995) in
Mongolian farmers living in the Yellow River Valley (YRV) where the drinking
water is contaminated by arsenic. In the present study, a brief sensory battery
including tests of visual acuity, contrast sensitivity, color discrimination
(Lanthony D-15) and tactile sensitivity was administered to 321 YRV residents.
Tactile thresholds in the 2nd and 5th fingers of both hands were assessed using a
biothesiometer and as-cending method of limits. Participants were divided into 3
exposure groups: low (<21 ug/L); medium (100-300 ug/L) and high (400-700
ug/L) arsenic in well water. Three measures of As exposure were obtained: water,
urinary and toe nail. Results indicate significantly higher vibrotactile thresholds
in the high exposure group compared to low and medium groups. Similar effects
were observed with the three measures of exposure, although the associations
were strongest with urinary and weakest with nail measures. No significant
differences were found in any visual measures. Arsenic is presently regulated as a
carcinogen. Results of the current study indicate neurosensory effects of arsenic
exposure at concentrations well below the 1000 ug/L level specified by NRC
(1999) and suggest that non-carcinogenic end-points such as tactile thresholds are
useful in the risk assessment of exposure to arsenic in drinking water.

CORRESPONDING AUTHOR: David Otto, EPA/Human Studies Division
(MD-58B), Research Triangle Park, NC 27711, USA.
DISCLAIMER: This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.




                                                        43
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




    ARSENIC INDUCED CARCINOGENESIS: PERTURBATIONS IN
   GLOBAL AND HA RAS METHYLATION PATTERNS IN METHYL-
    DEFICIENT C57BL/6 MICE; RESULTS OF A CHRONIC ANIMAL
                          BIOASSAY


John R. Froines Ph.D, University of California, Los Angeles


Abstract: We have studied the effect of arsenic and methyl-deficiency on the
methylation patterns of genomic and Ha-ras specific DNA. We hypothesize that
increased susceptibility to arsenic induced carcinogenesis results from a depletion of
methyl group reserves and a subsequent reduction in intracellular DNA methylation
reactions. Cellular methyl groups are depleted by chronic administration and
metabolism of inorganic arsenic. Nutritional depletion of methyl groups further
contributes to the deficiency resulting in a compromised DNA methylation process.
We demonstrate that coadministration of sodium arsenite and a methyl-deficient diet
to C57BL/6 mice results in global DNA and Ha-ras specific hypomethylation.
Methylation changes in DNA are associated with abnormal gene expression, cell
growth and possibly cancer. A 90-day subchronic animal bioassay conducted by our
laboratory indicates that animals administered arsenic and a methyl-deficient diet
display a dose-dependent increase in hypertrophy and hyperplasia of the bladder
epithelium as well as fatty changes and microgranulomas in livers. The association
between the observed hypomethylation and the histological changes has not been
determined. A chronic animal bioassay was conducted to examine the long-term
effects of arsenic and methyl-deficiency on C57BL/6 mice. Methyl-deficient mice
were administered sodium arsenite at 1.0 and 2.0 mg/kg/day. Exposure occurred for
18 months after which animals were necropsied and tissues analyzed for
histopathological changes. Preliminary results will be discussed.

CORRESPONDING AUTHOR: John R. Froines, Ph.D., Department of
Environmental Health Sciences, University of California, Los Angeles, Box
951772, Los Angeles, CA 90095-1772




                                         44
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




  LOW DOSE ARSENATE IN DRINKING WATER PREVENTS SKIN
TUMOR FORMATION IN A DMBA/TPA DEPENDENT MOUSE MODEL

Catherine B. Klein, Ph.D., NYU School of Medicine, Liza Snow, Ph.D., New
York University School of Medicine and Deakin University, Australia; Maarten
C. Bosland, D.V.M., Ph.D. NYU School of Medicine

         Although arsenic is an established human carcinogen, animal models of
arsenic carcinogenesis have had limited success. We have used the classic
DMBA/TPA mouse skin tumour model to assess the ability of arsenic to act as a
co-promoter or progressor of tumour formation in (C57Bl/6 X CBA) F1 mice.
The mice were given arsenic, as sodium arsenate, in their drinking water at one of
two sub-toxic doses, 0.2 mg/L or 2.0 mg/L starting two days prior to tumour
initiation with dimethylbenzanthracene (DMBA), followed by a standard
promotion regime using the phorbol ester, TPA, with continued exposure to
arsenic in the water. Several groups of mice were given an antioxidant, N-acetyl
cysteine (NAC), rather than As(V) in their water and other groups were given
both As(V) and NAC. Our results have shown, much to our surprise, that arsenic
produced a significant dose-dependent (41 to 63%) reduction in the papilloma
formation caused by the DMBA/TPA treatment. NAC alone also reduced tumour
formation by over 30% and the low dose of As(V) plus NAC together gave an
additive response that equalled the 60% reduction in tumour formation produced
by 2.0 mg/L As(V) alone. This result is consistent with our in vitro data that show
that chronic exposure to As(III) causes decreased AP-1 and NF-kB binding and a
decrease in the cellular response to TPA. Evaluation of the tumour pathology and
As levels in tissues is ongoing and results will be presented along with assays of
cellular response after long-term As exposure.

CORRESPONDING AUTHOR: Elizabeth T. Snow, Ph.D., Centre for Cellular
and Molecular Biology, School of Biological and Chemical Sciences, Deakin
University, 221 Burwood Highway, Burwood VIC 3125 AUSTRALIA




                                        45
     5TH International Conference on Arsenic Exposure and Health Effects
                            SPEAKERS ' ABSTRACTS




  MOLECULAR MECHANISM OF TRANSFORMATION IN MOUSE
      FIBROBLASTS INDUCED BY LOW DOSE OF ARSENIC

Yu Hu 1,2 MPH, Ph.D, Ximei Jin 1,2 M.D, Guoquan Wang M.D 2,
Elizabeth T Snow1 Ph.D. 1.School of Biological and Chemical
Sciences, Deakin University, Australia. 2. School of Public Health,
Xinjiang Medical University, China

         Arsenic is an important environmental chemical because it is
not only a critical compound for some medicine, especially in
leukemia treatment but also associated with the occurrence of adverse
health effects in human exposed by drinking water as well as
occupational exposure. However, mechanism of action of Arsenic is
still unclear. Alteration in intracellular redox status has been proposed
as one of major actions by arsenic. The purpose of this investigation
is to study the effect of As (III) on regulation of redox gene such as
Ref-1, GR, TRX and TR as well as prot-oncogene and tumor suppress
gene expression both in short-term and long-term treatment in mouse
fibroblast 3T3 cell. The interaction between As (III) and TPA and
H2O2 on these genes expression was also investigated. The results
showed that As (III) up-regulates the expression of TRX, TR, GR and
Ref-1, especially after long-term exposed to sub-micromolar dose As
(III), which is paralleled with cells morphology changes and
malignant transformation after long-term treatment with no toxic dose
As (III). Our results suggested that up-regulation of TRX and TR and
down-regulation of c-jun, c-fos as well as p53 after long-term As (III)
exposure may be required for induction of regeneration hyperplasia
which is close related to tumorigenesis through redox-regulate protein
kinases and modulate enzyme activities, cell surface or intercellular
receptors and transcription factors.

CORRESPONDING AUTHOR: Yu Hu MPH, Ph.D School of Public Health,
Xinjiang Medical University, 8 XinYi Rd,Urumqi, Xinjiang, 830054 China




                                     46
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




        HEALTH EFFECT MONITORING TO DNA DAMAGE OF
                    ARSENIC EXPOSURE

Hiroshi Yamauchi, Ph.D., Masahito Aminaka, Katusmi Yoshida, M.D., Ph.D., Dept.
of Preventive Medicine, St. Marianna University School of Medicine, Kawasaki,
JAPAN
Guifan Sun, M.D., Ph.D., School of Public Health, China Medical University,
Shenyang, CHINA

     The DNA damage is generated by the exposure of oxidized stress. This research
introduces the biological health effect monitoring method, which evaluates the DNA
damage caused to the arsenic exposure by 8-hydroxydeoxyguanosine (8-OHdG)
concentration in urine.
     The research subjects are five group: 1) 248 Japanese healthy people, 2) 95
Chinese healthy people, 3) 52 patients of acute arsenic poisoning, 4) 165 patients of
chronic arsenic poisoning in China, 5) 31 Japanese fishermen.
     The average concentrations of arsenic in urine of Japanese healthy people, acute
arsenic poisoning patients, chronic arsenic poisoning patients and Japanese fishermen
is 45.6136.6, 11481703 (after 10 days), 2581326 and 173174.0 mg As/g
creatinine, respectively. The average concentrations of 8-OHdG in urine of Japanese
healthy people, Chinese healthy people, acute arsenic poisoning patients, chronic
arsenic poisoning patients and Japanese fishermen is 15.415.6, 14.519.0, 25.219.8,
17.719.6 and 21.316.4 ng/mg creatinine, respectively.
    As for the excretion of 8-OHdG in urine from acute arsenic poisoning patients,
the tendency to actualize after the day tenth when arsenic had been taken was
observed. On the other hand, 8-OHdG concentrations in urine were recovered by the
spontaneous recovery within the range of a normal value one year from about half
a year later.
     8-OHdG concentrations in urine of the patient with chronic arsenic poisoning rise
by the inorganic arsenic exposure. When one year has passed since the arsenic
exposure was stopped, 8-OHdG concentrations in urine has been recovered within the
range of a normal value.
     For a general healthy person, in people who took the arsenic of excessive from
meal, the upturned of 8-OHdG concentrations in urine was observed.
     It is thought that the measurement of 8-OHdG concentrations in urine is an
effective, biological health effect monitoring method of the arsenic exposure.

CORRESPONDING AUTHOR: Hiroshi Yamauchi, Ph.D., Department of
Preventive Medicine, St. Marianna University School of Medicine, Kawasaki 216-
8511, JAPAN.




                                         47
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




 LABORATORY AND FIELD EVALUATION OF POTENTIAL ARSENIC
    EXPOSURE FROM MINE TAILINGS TO GRAZING CATTLE

Scott Bruce, BSc(Hons)., Barry Noller, PhD., Jack C. Ng, PhD., National Research
Centre for Environmental Toxicology, The University of Queensland, Australia

         In Australia, a main future use of rehabilitated mine-land is to stock grazing
animals. Criteria for environmental management and rehabilitation of mine sites have
become more stringent with the increasing awareness of the potential of harmful
elements including arsenic in tailings. Bioavailability data are lacking to provide
realistic health risk assessment of arsenic from mine tailings in Australian conditions.

         For the evaluation of comparative bioavailability, groups of 3 cattle were fed
5 days a week a diet spiked with mine tailings or sodium arsenate or arsenite for 8
months. Blood, biopsy of the muscle and liver were periodically collected to monitor
arsenic accumulation. At necropsy, blood, muscle, liver, kidney and other saleable
tissues were measured for arsenic concentrations.
         For the field validation, cattle were allowed to graze on rehabilitated tailings
facilities over 8-9 months. Our results indicated that although the concentrations of
arsenic in the tissues were higher than those of the control site, the levels were below
the Australian maximum permissible concentrations for beef intended for human
consumption. The rehabilitated mine tailings under the test conditions appear to be
suitable for grazing animals with no foreseen adverse health effects.
           Results obtained from this animal model should be a useful tool for
rehabilitation design of mined land in order to minimise health effects for animals and
humans. More data of this type will help regulatory agencies to develop guideline
values and policy in relationship to mine closure.

CORRESPONDING AUTHOR: Jack C. Ng, PhD., National Research Centre for
Environmental Toxicology, The University of Queensland, 39 Kessels Road, Coopers
Plains, Brisbane, Australia 4108. Email: j.ng@uq.edu.au




                                          49
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




 EVIDENCE FROM MOUSE CARCINOGENESIS STUDIES SUGGESTS
     THAT ARSENIC REQUIRES A CARCINOGENIC PARTNER

Toby G. Rossman, Ph.D., Ahmed N. Uddin, MD, Ph.D., Fredric J. Burns, Ph.D. and
Maarten C. Bosland, DVM, Ph.D. , New York University School of Medicine

Epidemiological studies show an association between inorganic arsenic in drinking
water and increased risk of cancers, yet animal models for arsenic carcinogenesis have
not been successful. This lack hinders mechanistic studies of arsenic carcinogenesis.
Previously, we found that low concentrations of arsenite are not mutagenic, but can
enhance the mutagenicity of other agents. This comutagenic effect appears to result
from inhibition of DNA repair by arsenite, but not via inhibition of DNA repair
enzymes. Rather, arsenite disrupts p53 function and enhances proliferative signaling
(Vogt and Rossman, Mutation Res. 478:159,2001). Failure to find animal models for
arsenic carcinogenesis might indicate that arsenite is not a complete carcinogen, but
rather acts as an enhancing agent (not a promoter, but a cocarcinogen). To test this
hypothesis, Skh1 mice were given 10 mg/l sodium arsenite in drinking water (or not)
and irradiated with 1.7 KJ/m2 solar UVR 3 times weekly. After 26 weeks, no tumors
appeared in any organs in control mice or in mice given arsenite alone, but irradiated
mice given arsenite had a 2.4-fold higher skin tumor yield than mice given UVR
alone. The tumors were mostly squamous cell carcinomas, and were larger and more
invasive in mice given UVR plus arsenite. These results support the hypothesis that
arsenic acts as a cocarcinogen with a second (genotoxic) agent by inhibiting DNA
repair and/or enhancing positive growth signaling. Similar experiments are being
carried out in a lung cancer model. The shape of the dose/response curve for skin
carcinogenesis is also being determined.

CORRESPONDING AUTHOR: Toby G. Rossman, Ph.D., Nelson Institute of
Environmental Medicine, New York University School of Medicine, 57 Old Forge
Road, Tuxedo, NY 10987, USA rossman@env.med.nyu.edu




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                             SPEAKERS ' ABSTRACTS




     MECHANISMS INVOLVED IN SODIUM ARSENITE-INDUCED
               CYTOGENETIC ALTERATIONS

Te-Chang Lee, Ph.D., Institute of Biomedical Sciences, Academia Sinica and Institute
of Pharmacology, National Yang-Ming University; Ling-Huei Yih, Ph.D., Graduate
Institute of Pharmacology and Toxicology, Tzu Chi University

       Multistep carcinogenesis requires a number of genetic changes. Inorganic
arsenic has been well documented to induce cytogenetic alterations such as
endoreduplication (diplochromosomes), chromosome aberrations, sister chromatid
exchanges, and aneuploidy in both in vivo and in vitro systems. We have demonstrated
that treatment of human fibroblasts (HFW) with 5 µM arsenite for 24 h resulted in
18% of subclones with one chromosome loss. The aneugenic activity of arsenite was
confirmed by formation of kinetochore positive micronuclei. Our recent data
demonstrated that arsenite could mimic spindle poisons to induce mitotic arrest in
several human cell lines. The interference of mitotic spindles by arsenite would lead
to the appearance of c-anaphase. Since arsenite-induced mitotic arrest and c-anaphase
were abrogated by staurosporine, a kinase inhibitor, an unidentified cascade for
protein phosphorylation and dephosphorylation was possibly involved in arsenite-
induced mitotic disturbance and cytogenetic alterations. Cytogenetic alterations and
chromosomal instability are frequently reported to be due to the failure of spindle-
assembly checkpoints.
     Evidence to date shows that most cancers manifest the genetic instability. In
most cancers, the instability is observed at the chromosome level, resulting in losses
and gains of whole chromosomes or large portions thereof. In our studies, we have
demonstrated that arsenic may cause DNA strand breaks, induce p53 accumulation,
and exert its aneugenic and/or clastogenic effects through disturbance of mitotic
events and attenuation of spindle dynamics.

CORRESPONDING AUTHOR: Te-Chang Lee. Ph. D., Institute of Biomedical
sciences, Academia Sinica, Taipei 115, Taiwan and Institute of Pharmacology,
National Yang-Ming University, Taipei 112, Taiwan.




                                         51
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                             SPEAKERS ' ABSTRACTS




 CARCINOGENICITY OF DIMETHYLARSINIC ACID AND RELEVANT
                      MECHANISMS

Shoji Fukushima, M.D., Hideki Wanibuchi, M.D., Min Wei, M.D., and
Keiichirou, Morimura, M.D. Department of Pathology, Osaka City University
Medical School, Japan

  Precise mechanisms by which arsenic induces cancer are unknown, in large part
due to the lack of an appropriate animal mode. In the present set of experiments,
we focused on a major organic metabolite of arsenic, dimethylarsinic acid
(DMA), found in most mammals including humans. We examined carcinogenicity
of DMA in male F344 rats in a 2-year carcinogenicity test, in addition to assessing
genetic alteration patterns in the induced tumors. Furthermore, to test the
hypothesis that ROS may play a role in DMA carcinogenesis, 8-hydroxy-2'-
deoxyguanosine (8-OHdG) formation in urinary bladder was examined.
  From weeks 97-104, urinary bladder tumors were observed in rats treated with
DMA at doses of 50 ppm (incidence, 29%) and 200 ppm (incidence, 36%), but
not at doses of 0 and 12.5 ppm. Mutation analysis showed these tumors to have a
low rate of H-ras mutations. No alterations of the p53, K-ras or _-catenin genes
were found, whereas aberrant protein expression of p27kip1, cyclin D1 and COX-2
could be demonstrated in the urinary bladder lesions by immunohistochemistry. 8-
OHdG formation level in urinary bladder DNA was significantly increased after
treatment with 200 ppm DMA in the drinking water for 2 weeks, as compared
with the controls.
  In conclusion, the present work provides unequivocal evidence that DMA is a
complete carcinogen for the rat urinary bladder. DMA-induced urinary bladder
tumors may occur as the result of accumulations of diverse genetic alterations.
Furthermore, generation of ROS is likely to play an important role in DMA
carcinogenesis.




                                        52
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




 TRANSPLACENTAL CARCINOGENICITY OF INORGANIC ARSENIC
 IN MICE: INDUCTION OF HEPATIC, OVARIAN, PULMONARY AND
                    ADRENAL TUMORS

Michael P. Waalkes, Ph.D., Jie Liu, Ph.D., NCI at NIEHS; Jerrold M. Ward,
D.V.M., Ph.D., NCI at Frederick; Bhalchandra A. Diwan, Ph.D., SAIC-Frederick

         Since gestation is a period of high sensitivity to chemical carcinogenesis,
we performed a transplacental carcinogenicity study where groups (n = 10) of
pregnant C3H mice received drinking water containing sodium arsenite at 0, 42.5
and 85 ppm arsenite ad libitum from day 8 to18 of gestation. Dams were allowed
to give birth, offspring were weaned (4 weeks) and put into gender-based groups
(n = 25) according to maternal exposure. During the study, which lasted up to 90
weeks, survival and body weights of the offspring were not reduced by the arsenic
exposure compared to control. A complete necropsy was performed on all mice
and tissues were examined by light microscopy in a blind fashion. In male
offspring, there was a marked, dose-related increase in hepatocellular carcinoma
incidence (control, 12%; 42.5 ppm, 38%; 85 ppm, 61%) and in liver tumor
multiplicity (tumors/liver; 5.6-fold over control at 85 ppm). A dose-related
increase in adrenal tumor incidence and multiplicity also occurred. In female
offspring, dose-related increases occurred in ovarian tumors (control, 8%; 42.5
ppm, 26%; 85 ppm, 38%), and in uterine proliferative lesions (hyperplasia plus
tumors; control, 16%; 42.5 ppm, 56%; 85 ppm, 63%). Arsenic also induced lung
carcinoma and oviduct proliferative lesions in females. In non-neoplastic areas of
liver from arsenic exposed animals there was a marked over-expression of
estrogen receptor-" and cyclin D1, a suspected hepatic oncogene. These results
demonstrate that inorganic arsenic exposure, as a single agent, can be carcinogenic
in mice. (Supported in part by NO1-CO-56000).

CORRESPONDING AUTHOR: Michael P. Waalkes, Ph.D., Inorganic
Carcinogenesis Section, Laboratory of Comparative Carcinogenesis, NCI at
NIEHS, 111 Alexander Drive, MD F0-09, PO Box 12233, Research Triangle
Park, NC 27709, USA.




                                        53
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




    CHARACTERIZATION OF THE ENZYMES INVOLVED IN THE
   BIOTRANSFORMATION OF INORGANIC ARSENIC BY HUMANS

H. Vasken Aposhian, Ph.D., Robert A Zakharyan, M.D., Ph.D., Adriana
Sampayo-Reyes, Ph.D., Timothy R. Radabaugh, B.S., and Dean E. Carter,
University of Arizona

        The biotransformation of inorganic arsenate to DMA involves a series of
enzymatic steps. We have previously reported that the enzyme responsible for the
reduction of arsenate to arsenite is human liver arsenate reductase. Our recent studies
based on amino acid homology and other properties demonstrate that human liver
arsenate reductase and human purine nucleoside phosphorylase (PNP) are identical
proteins. The reaction requires inosine and dihydrolipoic acid which is the most
potent naturally occurring dithiol. GSH is relatively inactive. PNP is an essential
enzyme involved in purine and thus nucleic acid metabolism. Arsenate
reductase/PNP will not reduce MMA(V).
The reduction of MMA(V) to the very toxic and reactive MMA(III) is catalyzed
by human liver MMA(V) reductase which our lab has demonstrated to be
identical to the new omega member of the glutathione S-transferase superfamily.
MMA(V) reductase has an absolute requirement for GSH. Most of the other
members of the glutathione-S-transferase superfamily will not reduce MMA(V).
Although at the time of this writing, the sequence of the human arsenic
methyltransferase is not known, in vitro and in vivo studies will be correlated to
compile a scaffold for the interactions of inorganic arsenic and its methylated
metabolites, including MMA(III) and DMA(III), with body constituents to attempt
an explanation for the toxicity of ingested inorganic arsenic.

CORRESPONDING AUTHOR: H. Vasken Aposhian, Ph.D., Department of
Molecular and Cellular Biology, University of Arizona, Life Sciences South
Building, P.O. Box 210106, Tucson, AZ, 85721-0106, USA.




                                          55
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




     PATHWAYS OF ARSENIC TRANSPORT AND DETOXIFICATION IN
               PROKARYOTES AND EUKARYOTES

Barry P. Rosen, Department of Biochemistry and Molecular Biology, Wayne State
University, School of Medicine.

  Life may have first arisen in deep oceanic hydrothermal vents that were rich in toxic
metals including arsenic. Maintaining suitable intracellular concentrations of essential
metals while excluding toxic metals such as arsenic was one of the earliest challenges of
the first cells. This ancient environmental challenge has been the driving force for the
evolution of mechanisms for metal ion homeostasis and detoxification. Even today toxic
metals such as arsenic enter the ecosphere from geochemical sources
(http://co.water.usgs.gov/trace/arsenic/). It is little wonder that in every organism
examined there are transport systems that detoxify metal ions by catalyzing extrusion
from the cytosol (1,2).
  This presentation will focus on the mechanisms of arsenic transport and detoxification
in the Escherichia coli and Saccharomyces cerevisiae (3). In both As(V) is taken up by
phosphate transporters, and aquaglyceroporins GlpF (4) and Fps1p facilitate As(III) entry
into cells. The first step in arsenate detoxification is biotransformation to As(III) by an
arsenite reductase, ArsC (5) or Acr2p (6). In both organisms, the next step involves
extrusion of As(III) from the cytosol. In E. coli extrusion is catalyzed by the ArsAB
ATPase (7). In yeast this is carried out by the arsenite carrier, Acr3p (8). In addition,
Ycf1p, a homologues of the human MRP drug pump, transports glutathione conjugates
of As(III) into the yeast vacuole (8).
  Identification of the routes of arsenic uptake and efflux in humans is of importance for
understanding its action as a human carcinogen and as a chemotherapeutic drug in the
treatment of leukemia. While at least one extrusion system has been identified, where
arsenic is pumped into bile by MRP2 in the form of As(GS)3, the pathways for arsenite
uptake are unknown. Recently we have shown that the mammalian aquaglyceroporin
AQP9 facilitates arsenite uptake into cells, suggesting that this protein could be a
pathway for arsenite uptake in humans. Supported by NIH grants GM52216 and
ES10344.
REFERENCES :
1. Rensing, C., Ghosh, M., and Rosen, B. P. (1999) J Bacteriol 181, 5891-5897
2. Gatti, D., Mitra, B., and Rosen, B. P. (2000) J Biol Chem 275, 34009-34012
3. Rosen, B. P. (1999) Trends Microbiol 7, 207-212
4. Sanders, O. I., Rensing, C., Kuroda, M., Mitra, B., and Rosen, B. P. (1997) J Bacteriol
179, 3365-3367
5. Shi, J., Vlamis-Gardikas, A., Åslund, F., Holmgren, A., and Rosen, B. P. (1999) J Biol
Chem 274, 36039-36042
6. Mukhopadhyay, R., Shi, J., and Rosen, B. P. (2000) J Biol Chem 275, 21149-21157
7. Rosen, B. P., Bhattacharjee, H., Zhou, T., and Walmsley, A. R. (1999) Biochim
Biophys Acta 1461, 207-215
8. Ghosh, M., Shen, J., and Rosen, B. P. (1999) Proc. Natl. Acad. Sci. USA 96, 5001-
5006
CORRESPONDING AUTHOR: Barry P. Rosen, Ph.D., Department of Biochemistry
& Molecular Biology, Wayne State University, School of Medicine, Detroit, MI 48201,
USA.



                                            56
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




             THE PATHWAY OF ARSENIC METHYLATION

David J. Thomas, Experimental Toxicology Division, National Health and
Environmental Effects Research Laboratory, Office of Research and
Development, U.S. Environmental Protection Agency, Research Triangle Park,
NC

        Understanding the metabolic processes that convert inorganic arsenic into
its methylated metabolites is central to understanding the mechanistic bases of the
toxicity and carcinogenicity of this metalloid. We purified a novel S-adenosyl-L-
methionine: arsenic(III) methyltransferase from liver cytosol of adult male Fischer
344 rats that catalyzes transfer of a methyl group from S-adenosyl-L-methionine
to trivalent arsenicals producing methylated and dimethylated arsenicals. The
mRNA for this protein predicts a 369 amino acid-residue protein (molecular mass
41056 D) that contains common methyltransferase sequence motifs. Based on
similarities in the sequence of the rat protein and other predicted protein
sequences, this enzyme is designated as rat Cyt19. Rat Cyt19 mRNA is expressed
in many rat tissues and human Cyt19 mRNA is expressed in HepG2 cells, a
human hepatoma cell line that methylates arsenic. However, Cyt19 mRNA is not
found in UROTsa cells, a human urothelial cell line that does not methylate
arsenic. Recombinant rat Cyt19 is fully active as an arsenic methyltransferase.
Human Cyt19 is a 375 amino acid-residue protein that is quite similar in sequence
to rat Cyt19 and recombinant human Cyt19 is also an arsenic methyltransferase.
The catalytic functions of both rat and human Cyt19 have an absolute requirement
for a dithiol-containing molecule. (This abstract does not necessarily reflect EPA
policy).




                                        57
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




  ARSENIC-INDUCED CHANGES IN CELL ADHESION MOLECULES
   (CAMS), E-SELECTIN AND MONOCYTE-CHEMOATTRACTANT
   PROTEIN-1 (MCP-1) EXPRESSION IN HUMAN UMBILICAL VEIN
                ENDOTHELIAL CELLS (HUVEC)

Michael W. Lieberman, Subbarao V. Kala, Geeta Kala, C. Wayne Smith, and
Haiyun Y. Cheng.
Departments of Pathology and Pediatrics, Baylor College of Medicine, Houston,
TX 77019

Arsenic is a risk factor in cardiovascular disease, yet relatively little is known
about the molecular mechanisms responsible for arsenic-induced cardiovascular
disease. Because CAMs, and Selectins are believed to be involved in
atherogenesis, we are evaluating the effects of arsenic (sodium arsenite) and its
methylated products, monomethylarsonic acid (MMAV), dimethylarsenic acid
(DMAV) and monomethylarsonous acid (MMAIII) on the expression of ICAM-1,
VCAM, E-selectin and MCP-1 in HUVEC. Sodium arsenite, MMAV and DMAV
do not alter the basal expression of these molecules when added to passage 2
HUVEC as determined by ELISA. TNFα or LPS stimulate the expression of
these molecules 3 to 8 fold within 6 hrs. Sodium arsenite inhibits the TNFα- or
LPS- stimulated expression of ICAM, VCAM, E-Selectin and MCP-1 in these
cells at relatively low concentrations (5-10 µM), while MMAV and DMAV are
without effect. Since NFκB activation is known to be important in TNFα- or LPS-
induced expression of CAMs and Selectins, we have examined the effects of
sodium arsenite on NFκB activity (determined by EMSA) as well as the
phosphorylation of IκB (Western blot). Sodium arsenite inhibits TNFα- or LPS-
stimulated IκB phosphorylation and NFκB activation in these cells. It is
postulated that arsenite inhibits TNFα- or LPS- stimulated synthesis of ICAM,
VCAM and E-selectin by preventing phosphorylation of IκB and NFκB
activation.

(Supported by NIH grant ENVIRONMENTAL SCIENCES-10289)




                                       58
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




        ENZYMATIC REDUCTION OF ARSENATE IN HEPATIC
               MITOCHONDRIA AND CYTOSOL

Zoltán Gregus, M.D., Ph.D., D.Sc. and Balázs Németi, M.D., University of Pécs,
Medical School

        Arsenate (AsV), a typical form of environmental arsenic, is converted in
the body into more toxic trivalent forms, primarily arsenite (AsIII). We have
studied reduction of AsV to AsIII in isolated rat liver mitochondria and cytosol.
        AsV-exposed mitochondria, which take up AsV like phosphate, rapidly
formed and exported AsIII. Mitochondrial AsIII formation depended on the
functional integrity of mitochondria and was sensitive to inhibitors of oxidative
phosphorylation. Solubilization of mitochondria abolished their AsV reductase
activity even in the presence of glutathione and NAD(P)H, precluding isolation of
mitochondrial AsV reductase.
        Rat liver cytosol also reduced AsV, provided an appropriate thiol, e.g.,
dithiothreitol (DTT), dimercaptopropanol or dimercaptopropanesulfonate, was
present. Based on the following findings, we have identified this thiol-dependent
cytosolic AsV reductase as purine nucleoside phosphorylase (PNP), an enzyme
that normally uses phosphate to cleave purine nucleosides (inosine or guanosine)
into bases (hypoxanhine or guanine) and ribose-1-phosphate, but can also use AsV
instead of phosphate. Cytosolic DTT-supported AsV reduction was increased up
to 100-fold by inosine or guanosine, but was inhibited by phosphate,
hypoxanhine, guanine and PNP inhibitors. AsV reductase and PNP activities
perfectly coeluted during chromatography of cytosol. Purified PNP exhibited AsV
reductase activity provided both DTT and inosine were present. The AsV
reductase activity of PNP exhibited a chemical responsiveness similar to that of
the cytosolic AsV reductase.
         Although mitochondria and cytosolic PNP can reduce AsV, their in vivo
role in formation of AsIII from AsV remains to be clarified. (For more
information see Toxicol. Sci. 66(1-S): 83-84, 2002.)

CORRESPONDING AUTHOR: Zoltán Gregus, M.D., Ph.D., D.Sc., Dept. of
Pharmacology, Univ. of Pécs, Med. School, Szigeti út 12, H-7643 Pécs, Hungary.




                                       59
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




ROLE OF MITOCHONDRIA IN THE GENOTOXICITY OF ARSENIC IN
                 MAMMALIAN CELLS


Su-Xian Liu1, Mercy M. Davidson2, Mohammad Athar3 and Tom K. Hei1,4,
1
  Center for Radiological Research, 2Department of Neurology, 3Department of
Dermatology, College of Physicians & Surgeons and, 4Department of
Environmental Health Sciences, Joseph Mailman School of Public Health,
Colombia University, New York, NY., 10032

        Although arsenic is a well established human carcinogen, its carcinogenic
mechanism is not clear. Using the human hamster hybrid (AL) cell assay that is
proficient in the recovery of deletion mutants, we showed previously that arsenic
is a potent gene and chromosomal mutagen and that reactive oxygen species
mediate its genotoxic response (PNAS 95:8103, 1998; PNAS 98: 1643, 2001). To
ascertain if mitochondria contributed to the genotoxicity of the trivalent sodium
arsenite, we used two complementary approaches. Treatment of enucleated cells
with arsenic followed by rescue fusion with karyoplasts resulted in a mutant yield
that was 3 fold higher than untreated cells. In contrast, arsenic treatment of
mitochondrial function/DNA depleted cells, generated by pretreatment with
Rhodamine-6G, followed by rescue fusion with cytoplasts resulted in few
mutations. These data illustrate that nucleus is not the only target of the
carcinogenic metal and that mitochondria may also play an important role in the
genotoxic response of mammalian cells to the metalloid metal as well.


CORRESPONDING AUTHOR: Tom K. Hei, Ph.D., Center for Radiological
Research, Columbia University, Vanderbilt Clinic 11-205, 630 West 168th Street,
New York, NY., 10032




                                        60
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




      METHYLATED ARSENICALS AND GENE TRANSCRIPTION
                      REGULATION

Miroslav Styblo, Ph.D., Zuzana Drobná, Ph.D., Ilona Jaspers, Ph.D., University of
North Carolina at Chapel Hill

Methylated arsenicals that contain either trivalent or pentavalent arsenic are products
of the enzymatic methylation of inorganic arsenic (iAs) in humans. Unlike their
pentavalent counterparts, methylated trivalent arsenicals, methylarsonous acid
(MAsIII) and dimethylarsinous acid (DMAsIII), are more cytotoxic, genotoxic and
more potent enzyme inhibitors than iAs. Previous studies on molecular mechanisms
of carcinogenic effects of iAs indicated that this arsenical does not act through classic
genotoxic or mutagenic mechanisms, but rather is a tumor promoter that interferes
with signal transduction pathways. Trivalent iAs, arsenite (iAsIII), has been shown to
modify expression and/or DNA binding activities of several transcription factors,
thereby modulating cell growth and proliferation. However, effects of methylated
arsenicals on gene transcription regulation have not been thoroughly characterized.
We have examined the composition and DNA binding activity of one of the major
transcription factors, activating protein-1 (AP-1), in several types of human cells
exposed to iAsIII, or to methylated trivalent arsenicals. All trivalent arsenicals, iAsIII,
MAsIII and DMAsIII, induced phosphorylation of c-Jun, DNA binding activity of AP-
1, and/or AP-1-dependent gene transcription in human primary hepatocytes, HepG2,
and urinary bladder cell lines, UROtsa and T24. Regardless of cell type, MAsIII and
DMAsIII were considerably more potent inducers of c-Jun phosphorylation and AP-1
activation than was iAsIII. Among cell types examined, UROtsa cells, a normal
human urothelium cells line, were the most sensitive to trivalent arsenicals, especially
to MAsIII. These results indicate that methylated trivalent arsenicals are more potent
than iAsIII in inducting AP-1-dependent gene transcription in human tissues,
particularly in bladder urothelium. (Supported by NIH grant ES09941.)

CORRESPONDING AUTHOR: Miroslav Styblo, Ph.D., Department of Pediatrics
and the Center for Environmental Medicine and Lung Biology, University of North
Carolina at Chapel Hill, CB# 7220, Chapel Hill, NC 27599-7220, USA.




                                           62
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




 ALTERED GENE EXPRESSION IN KERATINOCYTES FOLLOWING
                  ARSENIC EXPOSURE

Dori R. Germolec, Ph.D., Kevin J. Trouba, Ph.D., Hisham K. Hamadeh, Ph.D.,
Rupesh P. Amin, Ph.D., Kristen Geisenhoffer and Cynthia A. Afshari, Ph.D.,
National Institute of Environmental Health Sciences

Previous studies in our laboratory suggest that arsenic modulates neoplastic
disease in the skin by inducing overexpression of genes encoding specific
cytokines and growth factors. Using cDNA microarrays, we have determined that
non-toxic concentrations of arsenic modulate gene expression (e.g., oxidative
stress, glutathione metabolism, heat shock/stress response, cell proliferation, and
DNA damage) in normal human epidermal keratinocytes (NHEK). Based on
microarray data, cyclooxygenase-2 (Cox-2), a pro-inflammatory protein that is
regulated by oxidative stress, is robustly induced by arsenic in a dose- and time-
dependent manner. Northern blotting confirms increases in gene expression.
Arsenic influences Cox-2 expression posttranscriptionally at the protein level,
suggesting a functional relationship between arsenic exposure and prostaglandin
synthesis. The mechanism(s) by which arsenic regulates Cox-2 expression
appears to be mediated in part by mitogen and stress-related signal transducers.
PD98095 and SB202190, two specific inhibitors of mitogen and stress-related
signal transduction, respectively, serve to partially attenuate the ability of arsenic
to upregulate Cox-2 expression. Arsenic-induced Cox-2 expression in NHEK is
associated with cellular stress, demonstrated by the robust induction of Serine
threonine kinase 25 and NADPH oxidoreductase: two markers of oxidative stress.
Additional studies in our laboratory using the Tg.AC mouse in vivo indicate that
both inorganic and methylated arsenicals can modulate cell proliferation and
cytokine expression, an effect that may be directly or indirectly associated with
Cox-2 expression. Future studies will examine the relationship between arsenic-
induced pro-inflammatory cytokines, Cox-2, and stress-related gene expression
and the molecular mechanisms through which arsenic regulates Cox-2 expression.


Corresponding Author: Dori R. Germolec, Ph.D., Environmental Immunology
Laboratory, National Institute of Environmental Health Sciences, PO Box 12233,
RTP, NC, 27709




                                         63
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




  MULTIDRUG RESISTANCE TRANSPORT PROTEINS IN ARSENIC
                    TOXICOLOGY

Jie Liu, Ph.D., Michael P. Waalkes, Ph.D., NCI at NIEHS;
Yaping Liu, M.D. and Curtis D. Klaassen, Ph.D., University of Kansas Medical
Center

        We have shown that cultured rodent cells chronically exposed to inorganic
arsenic (As) develop tolerance to the metalloid associated with increased As efflux.
These As-tolerant cells show increased expression of several transporters including
multidrug resistance protein Mrp1 and Mrp2, as well as the multidrug resistance gene
MDR1. Mrp inhibitor MK571 and P-glycoprotein inhibitor PSC833 increased As
cytotoxicity in these cells by increasing cellular As accumulation. However, whether
such phenomena are relevant in vivo is not known. Thus, the mdr1a/1b(-/-) mice,
which lack mdr1-type P-glycoproteins, were examined for sensitivity to As toxicity
and accumulation. The mdr1a/1b(-/-) and wild-type mice were given a single dose of
sodium arsenite (12-19 mg/kg, sc), and toxicity was examined 24 hr later. The
mdr1a/1b(-/-) mice were more sensitive than wild-type mice to As-induced lethality.
Histologically, As produced more frequent and more severe lesions in the liver and
kidney of mdr1a/1b(-/-) mice than in wild-type mice. Serum alanine aminotransferase
activity and blood urea nitrogen levels, indicative of hepatic and renal damage
respectively, were increased 4-6 fold in the mdr1a/1b(-/-) mice as compared to 1-2
fold increases in wild-type mice. The mdr1a/1b(-/-) mice accumulated more As in
the liver (15.3 vs 5.2 µg/g), kidney (7.23 vs 3.22 µg/g), small intestine (3.98 vs 1.57
µg/g), and brain (0.45 vs 0.17 µg/g), as compared to wild-type mice 24 hr after
sodium arsenite (14 mg/kg, sc) administration. These data indicate multidrug-
resistance proteins and P-glycoproteins could function together to reduce cellular As
accumulation and thus make animals resistant to acute As toxicity.

Corresponding Author: Jie Liu, Ph.D., Inorganic Carcinogenesis Section, Laboratory
of Comparative Carcinogenesis, NCI at NIEHS, 111 Alexander Drive, Research
Triangle Park, NC 27709, USA




                                          64
      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




    GENE REGULATION BY LOW DOSE ARSENIC IN CULTURED
                     HUMAN CELLS

Liza Snow, Ph.D., Michael Schuliga, Ph.D., Yu Hu, M.D., Deakin University,
Australia

        We have evaluated the molecular responses of human epithelial cells to
low dose arsenic to ascertain how target cells may respond to physiologically
relevant concentrations of arsenic. Data gathered in numerous experiments in
different cell types all point to the same conclusion: low dose arsenic induces a
protective response against subsequent exposure to oxidative stress or DNA
damage, whereas higher doses often provoke synergistic toxicity. In particular,
exposure to low, sub-toxic doses of As(III) causes coordinate up-regulation of
multiple redox and redox-related genes including thioredoxin, thioredoxin
reductase, glutathione reductase, and γ-glutamylcysteine synthetase (required for
GSH synthesis). Glutathione peroxidase is down-regulated in fibroblasts, but up-
regulated in keratinocytes. The maximum effect on these redox genes occurs after
24 hours exposure to 5 to 10 :M As(III). This is 10-fold higher than the
maximum As concentrations required for induction of DNA repair genes (Sykora
and Snow), but within the dose region where DNA repair genes are coordinately
down regulated. Although arsenic toxicity may be caused, in part, by the transient
formation of reactive oxygen species (ROS), the observed effects on redox gene
expression are, to a large extent, independent of ROS formation. These changes in
gene regulation are brought about in part by changes in DNA binding activity of
the transcription factors AP-1 and NF-κB. Although sub-acute exposure to
micromolar As(III) up-regulates transcription factor binding, chronic exposure to
nanomolar As causes persistent down-regulation of this response. Altered
response patterns after long exposure to As may play a significant role in As
toxicology.

CORRESPONDING AUTHOR: Elizabeth T. Snow, Ph.D., Centre
for Cellular and Molecular Biology, School of Biological and
Chemical Sciences, Deakin University, 221 Burwood Highway,
Burwood VIC 3125 AUSTRALIA




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     CARCINOGENICITY OF DIMETHYLARSINIC ACID IN RATS

Samuel M. Cohen, M.D., Ph.D., Lora L. Arnold, M.S., University of Nebraska
Medical Center; X.C. Le, Ph.D., University of Alberta, Edmonton

        Dimethylarsinic acid (DMA) produces an increased incidence of bladder
tumors in rats when administered in a two-year bioassay either in the diet or in the
drinking water, with females being more susceptible than males. There is no
carcinogenic effect of DMA administered to mice, and there are no pre-neoplastic
changes in the hamster urinary tract when administered in the diet for 10 weeks.
In addition, DMA enhances the incidence of bladder tumors in male rats
administered after treatment with the bladder carcinogen, N-butyl-N-(4-
hydroxybutyl)nitrosamine (BBN). Evidence of urothelial cytotoxicity is present
within six hours after administration begins. By seven days, there is a consequent
regenerative hyperplasia, as evident by light and scanning electron microscopy
and by increased bromodeoxyuridine (BrdU) labeling index. The dose response
for toxicity and regeneration is the same as the dose response for tumorigenicity.
Co-administration of DMA with 2,3-dimercaptopropane-1-sulfonic acid (DMPS)
inhibits the toxicity and regeneration. The principal urinary metabolites following
DMA administration at 100 ppm of the diet are DMA and trimethylarsine oxide
(TMAO), but dimethylarsinous acid (DMAIII) is present in the urine at
concentrations of approximately 1-5 :M. In vitro, trivalent arsenicals, including
DMAIII, are cytotoxic at micromolar or lower concentrations whereas the
pentavalent organic arsenicals are cytotoxic to rat and human urothelial cells at
millimolar concentrations. Assessment of the carcinogenic risk of DMA to
humans must take into account the extraordinary doses required to produce the
effect in rats, the markedly different metabolism of DMA in rats compared to
humans, and the generally low levels to which humans are exposed.




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     ARSENIC-INDUCED CONGENITAL MALFORMATIONS IN
    GENETICALLY SUSCEPTIBLE FOLATE BINDING PROTEIN-2
                    KNOCKOUT MICE
1
  Ofer Spiegelstein, 2Xiufen Lu, 2Chris X. Le, 3Bogdan Wlodarczyk and 1Richard H.
Finnell
1
  Center for Environmental and Genetic Medicine, Institute of Biosciences and
Technology, Texas A&M University Health Science Center, Houston, TX;
2
  Department of Public Health Sciences, University of Alberta, Edmonton, Alberta,
Canada; 3University of Nebraska Medical Center, Omaha, NE.

Arsenic has been long suspected of being a human teratogen, although there is
currently insufficient and inadequate supportive data to make any definitive
judgments. In addition, the significance of individual genetic differences on
pregnancy outcomes following in utero exposure to arsenic is currently unknown. In
order to better understand the role of intracellular folate transport mechanisms in
arsenic-induced neural tube defects, we examined the effect of in utero exposure to
sodium arsenate in a genetically altered murine model in which the folate binding
protein 2 (Folbp2) gene has been inactivated by homologous recombination.
Administration of 40 mg/kg sodium arsenate by intraperitoneal injection at
gestational days 7½ and 8½, induced exencephaly in 40.6% of Folbp2-/- embryos,
compared to 24.0% in wild-type controls. The differences in response frequencies
were further exacerbated when the dams were fed a diet with decreased folate
content. Under these conditions, exencephaly was observed in 64.0% of Folbp2-/-
embryos, compared with 25.7% in controls. To test whether the differences in
susceptibility are due to differences in exposure, we performed a 24-h urinary
speciation analysis following a 30 mg/kg ip injection of sodium arsenate. The data
indicated that there were no significant differences in excretion of arsenicals between
the two genotypes, suggesting that the increased in utero susceptibility of Folbp2-/-
mice to arsenate may not be due to differences in biomethylation and exposure. We
are currently studying the effect of nutritional folic acid intake on arsenate
biotransformation in several folate transport knockout mouse strains.
This work was supported in part by grants DE13613, HD35396, ES09106 and
ES04917




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         THE REACTIVE OXYGEN SPECIES (ROS) THEORY
                OF ARSENIC CARCINOGENESIS.


Kirk T. Kitchin, Ph.D., US Environmental Protection Agency; Sarfaraz Ahmad
Ph.D., Mercer University

        At this time, there is not a scientific consensus on the mechanisms/modes of
action for arsenic carcinogenesis. Proposed mechanisms/modes of action for arsenic
carcinogenesis include but are not limited to clastogenic effects, mutation, oxidative
stress (via ROS and other chemical species), gene amplification, altered DNA
methylation, cell proliferation, promotion of carcinogenesis, effects on the
progression stage, inhibition of DNA repair and interaction with important cellular
proteins.
        Oxidative stress from arsenic exposure might result either (a) from arsenic
species such as dimethylarsenic radical and dimethylarsenic peroxy radical, (b) from
release of from ferritin (by dimethylarsinous acid (DMA(III)) and dimethylarsinic
acid (DMA(V))) or from induction of heme oxygenase (by arsenite), (c) from redox
cycling of trivalent to pentavalent arsenic forms or (d) from ROS such as superoxide,
hydrogen peroxide, hydroxy radical or singlet oxygen. Arsenic carcinogenesis may
proceed via hydroxy radical production by the Haber-Weiss reaction.
        Various investigators have shown that arsenic exposures increase 8-hydroxy-
2'-deoxyguanosine concentrations in mouse urine, rat liver and human skin.
Elevations in ROS concentrations can lead to increased 8-hydroxy-2'-
deoxyguanosine concentration, single strand breaks in DNA and G-->T mutations in
DNA.
        Arsenic is a human carcinogen in skin, lung, liver, urinary bladder and
kidney. Elucidating the mechanisms/modes of arsenic carcinogenesis would
contribute to a more quantitative and scientifically based risk assessment for arsenic,
a major world public health problem.
(Disclaimer: This is an abstract of a proposed presentation and does not necessarily
reflect EPA policy.)


CORRESPONDING AUTHOR: Kirk T. Kitchin, PhD., DABT,
MD-68, Cancer Biology Branch, Environmental Carcinogenesis Division, NHEERL,
US EPA, 86 Alexander Drive, Research Triangle Park, NC 27711, USA.




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  ARSENIC METABOLISM IN EISAI HYPERBILIRUBINEMIC (EHB)
    RATS: DISTRIBUTION AND EXCRETION IN RELATION TO
                    TRANSFORMATION

Kazuo T. Suzuki, Ph.D., Takayuki Tomita and Yasumitsu Ogra, Ph.D., Graduate
School of Pharmaceutical Sciences, Chiba University, Chiba, Japan

        Diverse chemical species of arsenic can be taken up by humans through
dietary foods and water. However, the most probable and toxic form of arsenic
exposed to humans is arsenite (iAsIII). Arsenite absorbed by the body is taken up by
the liver, and then transformed by consecutive methylation and reduction reactions
to the commonest final urinary metabolite, dimethylated arsenic (DMA). Namely,
iAsIII is oxidatively methylated to monomethylarsonic acid (MMAV), and then
reduced to monomethylarsonous acid (MMAIII) for further oxidative methylation to
dimethylarsinic acid (DMAV). In rats, DMAV is further reduced efficiently to
dimethylarsinous acid (DMAIII), and then excreted into the bloodstream, where
DMAIII is sequestered by red blood cells (RBCs), resulting in the preferential
accumulation of arsenic in rats.
        During the metabolic transformation of arsenic, substantial amount of iAsIII
injected intravenously (iv) into rats disappeared from both bloodstream and major
organs, and then reappeared after 6 hr mostly in the RBCs. The arsenic disappeared
from the bloodstream and major organs was assumed to be excreted into the bile, i.e.,
get into the hepato-enteric circulation in the form conjugated with glutathione (GSH)
(iAsIII(SG)3) during the metabolic transformation. However, substantial amount of
arsenic also disappeared in EHB rats, where arsenic is not excreted into the bile.
Nevertheless, the arsenic accumulating in the RBCs was much higher in EHB rats.
Then, the arsenic disappeared during the first 6 hr after the injection was traced and
explained by the distribution in the liver, muscle and other organs, and excretion to
urine and bile followed by the later redistribution to and accumulation in the RBCs.
It was not confirmed whether the arsenic distributed to organs other than liver
redistributes to RBCs after transformation to DMA or in the form of arsenite. MMA
is partly excreted into the bile in the GSH-conjugated form, a part of it being
reabsorbed. Further, MMA is partly excreted from the liver into the bloodstream.
DMA was not excreted into the bile.

Corresponding author: Kazuo T. Suzuki, Graduate School of Pharmaceutical
Sciences, Chiba 263-8522, Japan. E-mail: ktsuzuki@p.chiba-u.ac.jp




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  MOLECULAR APPROACHES TO DISSECT ARSENIC-DEPENDENT
                SIGNALING MECHANIMS


Deanna G. Adams, Ph.D., and Richard R. Vaillancourt, Ph.D., Department of
Pharmacology & Toxicology, University of Arizona College of Pharmacy


    Recent studies have demonstrated that arsenite activates the family of Mitogen-
Activated Protein (MAP) kinases that include c-Jun amino-terminal kinase (JNK),
p38 MAPK, and extracellular signal-regulated kinase (ERK). In transfection studies
of HEK293 cells, dominant-negative MEKK3 (MAPK/ERK Kinase Kinase)
inhibited arsenite-dependent activation of JNK, suggesting that endogenous MEKK3
is involved in arsenite signaling. The objective of this study was to identify and
characterize kinases that function upstream of MEKK3 in arsenite signal
transduction. We demonstrate that the stress-activated protein kinase, MEKK3, is
phosphorylated in vivo and in vitro in response to arsenite and activation of protein
kinase A (PKA). When (His)6FLAG•MEKK3 was expressed in Sf9 insect cells and
purified with Ni-Sepharose, we identified 14-3-3 protein by liquid chromatography
and electrospray tandem mass spectrometry (LC-MS) as co-purifying with
recombinant MEKK3. Since 14-3-3 proteins have been reported to interact with
proteins through phosphoserine, we sequenced (His)6FLAG•MEKK3 by LC-MS to
identify phosphorylated amino acids. Of the tryptic peptides sequenced, two
consisted of amino acids 164-174 and 335-349 and serines 166 and 337 were
phosphorylated within the respective peptides. Phosphorylation of both serines was
localized within two consensus PKA phosphorylation sites, RXX(S/T). Phospho-
specific antibodies were developed to recognize phosphorylated serine 166 of
MEKK3. These antibodies detected phosphorylation of MEKK3 at serine 166 in
response to arsenite and activation of PKA with forskolin. These results suggest that
arsenite regulates MEKK3 phosphorylation through a mechanism that involves PKA.


CORRESPONDING AUTHOR: Richard R. Vaillancourt, Ph.D., Department of
Pharmacology & Toxicology, University of Arizona College of Pharmacy, Tucson,
AZ 85721-0207, USA




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  INCORPORATING MECHANISTIC INSIGHTS IN A PBPK MODEL
                    FOR ARSENIC

Elaina M. Kenyon, Michael F. Hughes, Marina V. Evans, David J. Thomas, U.S.
EPA; Miroslav Styblo, University of North Carolina; Michael Easterling, Analytical
Sciences, Inc.

        A physiologically based pharmacokinetic (PBPK) model for arsenic provides
an integrated framework for addressing issues related to risk assessment, as well as
being a tool for hypothesis testing and experimental design. This is because a PBPK
model defines the relationship between external exposure and an internal measure of
(biologically effective) dose. The arsenic PBPK model is necessarily complex
because of the existence of multiple biologically-active forms and uncertainty
concerning their roles in producing toxic effects. Functionally, for arsenic this
requires a minimum of 4 submodels linked by reduction/oxidation and methylation
as well as incorporation of urinary excretion for each metabolite and tissue binding
for certain trivalent forms. This is necessary since the availability of arsenate,
arsenite and methylated forms for tissue interactions is a balance between rates of
excretion, binding, redox cycling and methylation. Our current PBPK model
structure will be reviewed in this presentation and unique mechanistic features,
together with their experimental basis, will be highlighted. These include
dimethylarsinic acid accumulation in lung, inhibition of the second methylation step
by arsenite, and assumptions regarding transport and partitioning into tissues. Our
modeling experiments and sensitivity analysis have also suggested several important
lines of research. Critical information to gather in human populations include data
on differences in methylation capacity, improved temporal data on exposure and
urinary excretion of arsenic metabolites, and speciated tissue distribution data from
autopsy samples. [This abstract does not reflect EPA policy.]

CORRESPONDING AUTHOR: Elaina M. Kenyon, Ph.D., U.S. EPA,
NHEERL/ETD/PKB, MD-74, Research Triangle Park, NC 27711, USA.




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       ARSENIC, DRINKING WATER, AND HEALTH: A REVIEW

Kenneth G. Brown, Ph.D., KBinc; Gilbert L. Ross, M.D., American Council on
Science and Health

        This presentation reviews issues and sources of uncertainty related to
assessment of health risks from arsenic in drinking water in the U.S. and how they
have arisen. It also chronicles some of the major arsenic-related regulatory activities
of U.S. EPA. EPA is directed by the Safe Drinking Water Act (SDWA) of 1974 to
establish national standards for contaminants in public drinking-water supplies.
Almost coincidental with an EPA draft risk assessment in 1984 related to skin
cancer, new epidemiological and other scientific articles began to proliferate, linking
arsenic in drinking water to cancer at internal sites and to additional non-cancer
effects, and reporting results related to biomarkers of exposure and mode-of-action.
It also came to light that arsenic toxicity from drinking water was of severe-to-
epidemic proportions in several regions of the world, fueling further concern for
public health in the U.S. EPA and stakeholders were motivated to fund workshops
and further research, producing still more scientific reports. Definitive resolution of
some risk-related controversies remained stymied, however, by limitations of
observational data and incomplete knowledge of complex issues related to kinetics
and mechanisms of toxicity. EPA finally commissioned the National Research
Council to evaluate the scientific evidence, and set a "final" rule of 10 :g/L in
January, 2001. A nine-month delay followed the appointment of the new EPA
administrator, however, to have three committees reconsider the evidence on health
risks, economics, and cost-benefit, before the "final" rule became the final rule.

CORRESPONDING AUTHOR: Kenneth G. Brown, 511 Palafox Drive, Chapel
Hill, NC 27516, USA.




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PROGRESS TOWARD A BIOLOGICALLY REALISTIC CANCER RISK
          ASSESSMENT FOR INORGANIC ARSENIC

Harvey J. Clewell, ENVIRON Int’l Corp.; Melvin E. Andersen, Colorado State
University; Janice W. Yager, EPRI.

        Trivalent arsenic species bind avidly to cellular proteins, especially those
containing vicinal dithiols, disrupting cellular function. For an arsenic mode of
action involving inhibition of critical cellular proteins, a sharp transition can be
expected from concentrations of arsenic with little effect to those at which
inhibition of one or more key cellular proteins becomes sufficient to cause
toxicity or carcinogenicity. However, nutritional, pharmacokinetic, and genetic
factors also alter the quantitative relationship between drinking water
concentrations of arsenic and the expression of specific tissue responses across
individuals. Physiologically based pharmacokinetic and biologically based dose-
response modeling will play a crucial role in integrating dosimetric and
mechanistic information into a quantitative framework suitable for conducting a
scientifically plausible risk assessment for arsenic. These same modeling
approaches can also be used in the context of Monte Carlo analysis to evaluate the
impact of inter-individual variability on the aggregate dose-response for the
population. This presentation will reviews recent progress, ongoing efforts, and
needed research to (1) characterize the dose-response for the cellular effects of
arsenic, (2) establish the metabolism and distribution of the various arsenic
species at high, tumorigenic and lower environmental exposures, and (3) develop
biologically based dose-response modeling approaches for linking tissue exposure
to one or more of the arsenic species with the eventual production of tumors. The
potential for using a biologically based dose-response model to conduct a
quantitative, nonlinear cancer risk assessment for arsenic that considers human
inter-individual variability will be discussed.

CORRESPONDING AUTHOR: Harvey Clewell, ENVIRON Int’l Corp., 602
E. Georgia Ave., Ruston, LA 71270, USA.




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                                SPEAKERS ' ABSTRACTS




     NATURAL HISTORY OF ARSENICOSIS IN AN ARSENIC ENDEMIC
     AREA OF WEST BENGAL, INDIA : A 5 YEAR FOLLOW UP STUDY.

DN Guha Mazumder1, M.D., FAMS, Nilima Ghose1, MBBS, Kunal Mazumder1,
MD, Allan H Smith2, PhD, Amal K Santra1, PhD, Sarbari Lahiri1, PhD, & Subhankar
Das1, MSc
1
    Institute of Post Graduate Medical Education & Research, Kolkata, India
2
    University of California, Berkeley, USA

Introduction:

Information on natural history of chronic arsenic toxicity following drinking As free
water is scanty. Medical treatment of arsenicosis to modify the health effects, is
unsatisfactory. Result of long term intake of arsenic free water in the affected people
in an Arsenic endemic area need to be fully ascertained to understand the effect of
intervention programme of providing safe water to the affected community. A cohort
follow up study was therefore conducted on 1074 people in the year 2000, 5 years
after initial clinical epidemiological study carried out in the year 1995 with past
history of drinking safe (As level ≤ 0.05 mg) (n=451) and unsafe water (As level >
0.05 mg/L) (n=623).

Inspite of availability of safe water 568 out of 623 people were found to be taking
safe water (As level < 0.05 mg/L). In the previous study 217 (38.2%) had skin lesion
(Pigmentation, Keratosis or both) out of which 18 people died. In the follow up study
47 people (8.27%) had new appearance of skin lesion. Out of 199 people whose skin
lesions were reexamined, the lesions cleared in 40 (20.1%), decreased in 59 (29.6%),
remained same in 95 (47.7%) and increased in 5 (2.5%). Urine arsenic was measured
in 474 i.e. 83.4% of participants out of which 156 i.e. 32.9% had urine arsenic level
≤ 50 :gm/L and 318 i.e. 67.1% had urine arsenic level > 50 mg/L. It was intriguing
to note that 67% of participants apparently taking safe water at present showed urine
arsenic > 50 mg/L, indicating exposure of arsenic from other sources besides water
in the surveyed area. Some study indicate that food may be another source.

Major causes of morbidity and mortality in the previously arsenic exposed population
were chronic lung disease, cerevrovascular accident and various cancers.

There was significant difference in morbidity and mortality in people having history
of drinking unsafe water compared to the control population studied. Detail data will
be presented in the conference.

Corresponding Author : Dr. DN Guha Mazumder, Instt. Post. Grad. Med. Edun &
Res., 244, AJC Bose Road, Kolkata – 700 020. India. Email- dngm@apexmail.com




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      SAHA'S GRADING OF ARSENICOSIS PROGRESSION AND PATIENT
                                       TREATMENT
Kshitish C. Saha, MD, DTM&H, D.Dermat.
Ex Professor and Head of Dermatology, The School of Tropical Medicine, Kolkata
West Bengal, India
Abstract:
         ARSENICOSIS in West Bengal, India and Bangladesh was discovered by the
author in 1982 and 1984 respectively. Since 1983, periodical field survey showed
increasing severity of ARSENICOSIS. The disease due to ARSENICOSIS was
confirmed by high arsenic level in consumed water, urine, nails, hair and skin scales.
The arsenic content was initially estimated by silver diethyl dithio carbazine method at
the School of Tropical Medicine and much later by flow injection hydride generation
atomic absorption spectrometry method at the School of Environmental Studies,
Jadavpur University, Kolkata, India.
         According to severity, progression of ARSENICOSIS has been classified by the
author into 4 stages, 7 grades and 20 sub-grades. The 4 stages are I) Pre-clinical, II)
Clinical, III) Complication and IV) Malignancy. Each stage is further graded as follows.
Pre-clinical (stage I) is graded 0 with 2 sub-grades; 0a (labile or blood phase) and 0b
(stable or tissue phase). Clinical stage (stage II) has been subdivided to four grades, 1)
Melanosis 2) Spotted keratosis on palms or soles, 3) Diffuse keratosis on palms and
soles and 4) Dorsal keratosis. Each of the four grades has been further subdivided into
three sub-grades, a, b, and c according to severity. Complications (stage III) and
Malignancy (stages 1V) are graded 5 and 6 respectively; each of the grades has been
further subdivided to a, b, and c.
         The features of different sub-grades are as follows, Diffuse Melanosis on palms
(1a), Spotted Melanosis on trunk (1b), Generalized Melanosis (1c), Number of Keratotic
nodules 0-6 (2a), Number of Keratotic nodules more than 6 (2b), Large Keratotic
nodules (2c), Diffuse keratosis on palms or soles (3a), Diffuse keratosis on both palms
and soles (3b), Diffuse keratosis complete on whole palms and soles (3c), Nodular
lesions on hands or feet (4a), Nodular lesions on hands and feet (4b), Nodular lesions on
hands and feet along with extension of keratosis all over the body (4c), Palpable liver
(5a), Jaundice (5b), Ascitis (5c), Malignancy with single lesion (6a), Malignancy having
two lesions (6b), and Malignancy having more than two lesions (6c).
         The various stages of ARSENICOSIS can be clinically treated as follows. Grade
0 can be eliminated by replacing arsenic contaminated with arsenic free water. Also
other treatment is applied on the patients of advanced grades along with supply of
arsenic free water. The chelating agent, dimercapto propane sulphonate (DMPS), therapy
is carried out at grade 2b onwards; the complication may be prevented however, there is
little improvement of Keratosis. The prognosis of grades 5b onwards is poor. At the
stage of malignancy, i.e. stage 4 (grades 6a, 6b, and 6c), surgical removal can only help
patients of grade 6a and 6b provided glands are not affected.
         Such differentiation of various stages of ARSENICOSIS is helpful to detect
asymptomatic cases in pre-clinical or sub-clinical phase and to find the severity of the
disease in order to prevent its further progress to complication and malignancy stages.
Corresponding Author: Dr Kshitish C                 Calcutta- 700064, West Bengal, India.
Saha, MD, DTM&H, D. Dermat.                         Ph-91-33-337-5090 and 91-33-241-
Ex. Professor and Head of Dermatology               3023
The School of Tropical Medicine,                    E mail debasaha@yahoo.com, and
Calcutta                                            sukantapoddar@yahoo.com
EC-21, Sector-1, Salt-Lake City,


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             UNICEF AND ARSENIC MITIGATION
     A REPORT OF THE THIRD PHASE WORK IN BANGLADESH

         Since UNICEF supported its long term counterpart, the Department of
Public Health Engineering, to conduct the first and so far largest national random
survey for arsenic contamination in Bangladesh between 1996 -1998, the
organisation has used every available resource to work to develop and implement
arsenic mitigation activities.
         While these efforts center on Bangladesh because that is by far where the
most widespread and severe contamination exists by today’s understanding, the
organisation is also leading efforts in other countries where arsenic has been
discovered. Mitigation programmes are also being supported in Nepal, Cambodia,
India, Vietnam, Thailand and China. Using its global reach and experience, the
organisation is able to quickly share successes and experiences not only from and
between those countries where mitigation projects are being implemented, but
also from its headquarters where new knowledge and ideas are being transmitted
frequently to the field. Thus a global sized “learning by doing” is taking place.
         In Bangladesh, the magnitude of the task and the consequent size of the
effort needed, have being growing rapidly as new understanding becomes
available with regard to the consequences of not treating this problem as a race
against time. For example the Columbia University discovered in its study area
that over 50% of the contaminated hand pumps had actually only been installed
for less than 5 years. If this is indicative of the other hand pumps in the country
then this could well be an explanation as to why the number of arsencicosis
patients is not yet in the hundreds of thousands as might be expected . It might
also mean that perhaps the programme is in a window of opportunity now to
prevent those many thousands of cases from occurring; but certainly with no time
to lose.
         UNICEf’s responsibility has been growing since the first random national
survey. Work has been developed in four phases so far, as ten per cent of the
nations upazilas have been entrusted to the organisation in partnership with
DPHE, most of these being in the “hot spot” upazilas. The first phase was the
random national survey. The second was the five upazila action research project.
The third phase was a additional fifteen upazila expansion and the fourth phase
will be implemented in 2002, a further 25 upazilas making a project area of 45
upazilas in all.
         So far over 450,000 tube wells have been tested by the UNICEF-DPHE
Project work. In 2002 another 500,000 will be tested making almost one million
in all. This work has discovered hundreds of villages that have no safe source at
all. More than 1,600 new arsenicosis patients have been diagnosed just in the
third phase upazilas. In addition to the testing programme, the project must divert
some resources and ingenuity to helping people to obtain a safe water source; for
until all people have access to safe water the job will not be complete.

Author: Colin Davis, UNICEF: cdavis@unicef.org




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 THE WORLD HEALTH ORGANIZATION NORMATIVE ROLES IN
MITIGATING HEALTH IMPACTS OF ARSENIC IN SOUTH EAST ASIA
                       REGION


Deoraj Caussy, Ph.D., Evidence for Information and Policy, World Health
Organization, Office of the South East Asia Region.


Ground water contamination, in excess of the World Health Organization (WHO)
guideline value of 0.01 mg/L, has been observed in many parts of the world
including India, Bangladesh, Thailand, Myanmar, Nepal, China, Taiwan and
Vietnam among others. In the South East Asia Region of WHO, it is currently
estimated that about 30 million persons may have been exposed to contaminated
ground water at various concentrations of arsenic and almost a quarter of a million
exposed subjects are already showing overt symptoms of chronic arsenic
poisoning. A review of the epidemiological data shows that there is a need for
internationally accepted criteria based on evidence in the following areas:
Exposure assessment, case-definition and case management. This paper reviews
the existing epidemiological evidence for standard case definition and
management and presents WHO strategic goals to meet these objectives. Efforts
are on the way to define a regional protocol for case definition and case
management. The availability of such guidelines will remove the wide variation
between studies describing prevalence rates or efficacy of a medical treatment and
ensure consistency of training for health care workers.

CORRESPONDING AUTHOR: Deoraj Caussy, Ph.D., Department of Evidence
for Information and Policy, World Health Organization, Office of the South East
Asia, World Health House, Ring Road, New Delhi 110 002, INDIA




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  ONLY PAINTING TUBEWELLS RED OR GREEN, DOES NOT HELP
                  ARSENICOSIS PATIENTS


Quazi Quamruzzaman, FRCS, Mahmuder Rahman, FRCP, M. A. Salam, Ph.D.,
A. I. Joarder, MBBS, Dip.Orth, M. Shahjahan, MBBS Dip.IH, S. U. Mollah,
MBBS, Dhaka Community Hospital


         The problem of the arsenic contamination of hand-pump shallow
tubewells in Bangladesh became known in 1993. As 97% of the population drink
tubewell water, various studies have predicted that nearly 85 million people are at
risk from arsenic poisoning.
         The experience of working at the field level in Bangladesh shows that the
present mitigation programmes may not be effective due to faulty design. These
programmes are mainly centred on identifying contaminated tubewells by field
test kits and then painting the tubewell red or green for unsafe or safe. Some
programmes include models of alternative water supply options and some include
field level patient identification with the provision of vitamins and ointments for
lesions.
         The Dhaka Community Hospital experience of treating hundreds of
affected patients demonstrates that investigation, diagnosis, appropriate treatment,
physical and socio-economic rehabilitation and cost analysis should be essential
components of any arsenic mitigation programme.
         The current emphasis of programmes and funds on safe water supply only,
ignores the human dimension of the arsenic problem. Safe water supplies are
essential but the management of those already affected by arsenicosis should be
the main focus of any arsenic mitigation programme.


CORRESPONDING AUTHOR: Quazi Quamruzzaman, FRCS, Dhaka
Community Hospital, 190/1 Wireless Railgate, Boro Maghbazaar, Dhaka 1219,
Bangladesh.




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




 WEB SITE ARSENIC REMEDIATION DATABASE OF > 50 OPTIONS


              Susan Murcott, Massachusetts Institute of Technology

         Knowledge of the extent of arsenic occurrence and its effect on public
health has not kept pace with remediation efforts. Arsenic contamination was
discovered in West Bengal in the early 1980s and in neighboring Bangladesh in
the early 1990s. Ten to twenty years have passed without adequate solutions
becoming generally available. This gap – between knowledge and action to
provide safe, alternatives to contaminated tubewells - has real-life impacts,
especially for the poor in West Bengal, Bangladesh and other arsenic-impacted
countries.
         The first step to action is to know the alternatives. To date, the World
Wide Web has not been used to its potential to provide and exchange information
specifically about arsenic remediation options. To help remedy this information
gap, this paper begins by reviewing the major Web sites that cover multiple
arsenic remediation options, then it presents the author’s arsenic remediation
Web site: http://web.mit.edu/murcott/www/arsenic. This site discusses the
universe of arsenic remediation methods, beginning with alternatives to
contaminated tubewells, then covering over 50 tubewell treatment technologies.
Applying a common template, each technology in the database is described in
detail, including its performance, the analytic method used to determine
performance, and the sites of lab, pilot, or full-scale tests. All tubewell treatment
options are categorized according to the dominant treatment process: oxidation,
coagulation/precipitation, filtration, adsorption, ion exchange, membrane
processes, biological and “other,” so that similar technologies and approaches can
be compared. We learn what equipment is needed, step-by-step procedures used
to carry out lab and field tests, capital and O&M costs, sludge issues, and which
options are promoted by which agencies, companies, and academic institutions.
Links and email addresses are given wherever possible. Finally, published
references are listed. This Web site serves as a knowledge base and educational
tool. Hopefully, this information will facilitate speedier mitigation efforts and
actions.


CORRESPONDING AUTHOR: Susan Murcott, Department of Civil and
Environmental Engineering, Massachusetts Institute of Technology, 77
Massachusetts Avenue, 1-138, Cambridge, Ma. 02139 Email: murcott@mit.edu




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




      ARSENIC MITIGATION: CHALLENGES OF BANGLADESH


Chowdhury M. Ahmed, Ministry of Local Government Rural Development &
Co-operatives, Government of the Peoples Republic of Bangladesh.


        Bangladesh has been facing multifarious challenges in addressing the
problem of arsenic contamination of ground water, which has become a public
health problem of catastrophic proportion.
        Lack of adequate knowledge about the cause, nature and scale of the
problem made the designing of mitigation measures a difficult job. Drinking
water supply in Bangladesh, particularly in rural areas, is predominantly based on
an estimated 8-9 million individual tube wells, a substantial portion of which is
believed to be contaminated with arsenic above acceptable limits.
        The intricate distribution pattern of arsenic contaminated aquifers and the
spatial variability of arsenic concentration from well to well have made testing of
each and every tube well in potential arsenic contaminated areas essential.
However, the scarcity of testing facilities including adequate field test kits with
required efficiency has made this task even more complicated. But the toughest
challenge comes in providing safe drinking water supply in affected areas.
Alternative water sources are not always easy to identify as alternative options,
may be expensive or not yet proven as safe and effective.
        Absence of any known treatment for arsenicosis patients has made patient
management a delicate business. Lack of established patient identification and
management protocols make the situation more awkward. Creating social
awareness and building necessary capacity at various levels to tackle the impact of
the problem are demanding tasks.
        Developing an appropriate institutional arrangement with redefined role of
various stakeholders for sustainable management of the problem is also a tricky
job, given the differing interest and orientation of various stakeholders.


CORESPONDING AUTHOR: Chowdhury Mufad Ahmed, Coordinator, Arsenic
Policy Support Unit and Senior Assistant Secretary, Local Government Division,
Ministry of Local Government Rural Development & Co-operatives, Government
of the Peoples Republic of Bangladesh. Bangladesh Secretariat, Dhaka,
Bangladesh.




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       5TH International Conference on Arsenic Exposure and Health Effects
                              SPEAKERS ' ABSTRACTS




  INVESTIGATION OF ARSENIC REMOVING TECHNOLOGIES FOR
              DRINKING WATER IN VIETNAM

Viet H. Pham, Ph.D., Con H. Tran, Ph.D., Ha T. Cao, Ph.D., Hanoi University of Science;
Michael Berg, M.Sc., Walter Giger, Ph.D., Roland Schertenleib, Swiss Federal Institute for
Environmental Science and Technology

         The arsenic contamination in groundwater was discovered in many areas of
Vietnam. It is a challenge to spur scientists and technologists to find out suitable
technologies and equipments for arsenic removal from drinking water. The first thing we
have investigated focused on arsenic removal for supply water of main water treatment
plants in cities. The research methodology was based on the existing water treatment
process of water treatment plants and made advantages of their available technology. There
were investigations on adsorption kinetics of As (III) and As (V) species onto iron (III)
hydroxide formed during the aeration step. The obtaained results showed that adsorption
ability of arsenate was more better than arsenite species and active chlorine using for
disinfection could totally oxidize arsenite (III) into arsenate (V). The minimal amount of
iron in groundwater needed for 0.5 mg/L arsenate removal was found out approximate 5
mg/L, while those for arsenite was more than 25 mg/L. The investigation suggested that it
should be changed disinfection step from the end point of water treatment process to the site
of coagulation or after aeration step.
         The above-mentioned arsenic removal technology could not be applied for families
where they used to take arsenic contaminated groundwater directly from tubewells as
drinking water. At present, there are millions of people using the contaminated groundwater.
To save people from potential arsenic infection, we suggested to use adsorption-columns
filled by arsenic removing materials such as denaturated oxidic iron’s ores (such as
Limonite and Laterite). Laterite and Limonite (local people called as Bee-Nest-Stone and
Vermilion) are abundant minerals in Northern Vietnam. Many authors affirmed the
adsorption ability of iron oxide and iron hydroxide but there was no serious investigation
on laterite and limonite.
         The iron ores were firstly dried, grained and sieved to particles with size of 0.1-1.0
mm. Then they were thermally pretreated at 500, 700, 800 and 900O C in order to remove
water-trace and vapor components including sublimate arsenous component. X-ray
diffraction measurement of limonite showed that the iron oxide (α-Fe2O3) composition was
not changed after calcination even at 900oC. But Fe2O3.H2O species were not almost existent
at 700oC. All kinds of the pretreated samples and the untreated samples (it was only dried
at 150oC) were tested for their arsenic adsorption ability. It was interesting that the untreated
limonite and laterite were of higher adsorption ability than the treated ones. The Langmuir
adsorption isotherms were determined for kinetic investigation of adsorption process. The
maximal adsorption capacity of limonite was approximately 900 mg/kg for As(V) and 500
mg/kg for As(III) based on its equilibration with aquous solutions of arsenic concentrations
lower than 1000 ppb.
         An important aspect of this research was that full adsorbed sorbent could be totally
regenerated simply by using sodium hydroxide solution. Beside that, it showed clearly that
the water after arsenic removal by those ores were not containing secondary pollution
substances.
CORRESPONDING AUTHOR: Viet H. Pham, Ph.D., Centre for Environmental
Chemistry, Hanoi University of Science, 334 Nguyen Trai Road, Thanh Xuan District,
Hanoi, Vietnam


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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




REMOVING ARSENIC FROM DRINKING WATER: A BRIEF REVIEW
  OF SOME LESSONS LEARNED AND GAPS ARISED IN CHILEAN
                   WATER UTILITIES.

Ana María Sancha F., Associate Professor, Universidad de Chile

        Theoretically, Arsenic removal from water can be achieved by using different
technologies. Application at full scale of each one might not be as successful as at
laboratory tests. The difference between the laboratory and full scale performances
may reflect the control over different variables involved in the Arsenic removal
proccess.At full scale some variables are difficult to control and these may interfere
in the removal process. These interferences may not be detected when working at
laboratory tests with analito (As) solutions in distilled water.
        The selection of the best available technology for Arsenic removal should be
based on some key factors, such as: removal goals,quality of the water matrix, water
quantity, skill operator requirements, operational water treatment costs, arsenic
speciation,availability of analytical methods ,sludge management, and others.
        Some of these issues may play an important role in the feasability of
Arsenic removal practices and therefore must be considered and assesed before the
selection of any Arsenic removal technology.Small water utilities may face more
challenges than larger systems.The situation for family systems is even worst.
        This paper addresses a critical review of some of this issues and the lessons
learned about Arsenic removal in Chilean water utilities in the last 30 years.Solutions
for an As- water-dependant society should be not so hard to find when experience
and creative knowledge are used.

CORRESPONDING AUTHOR:Ana María Sancha, División de Recursos Hídricos
y Medio Ambiente, Facultad de Ciencias Físicas y Matemáticas, Universidad de
Chile, P.O.Box 228/3 Santiago, Chile.
 e-mail:amsancha @ing.uchile.cl




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




     ARSENIC REMOVAL TECHNOLOGIES IN THE FINAL RULE

Jeffrey B. Kempic & Amit Kapadia, United States Environmental Protection Agency

         In developing drinking water regulations, the United States Environmental
Protection Agency (EPA) is required to identify technologies that can be used to
meet the maximum contaminant level (MCL). EPA is required to identify treatment
technologies for large systems (called best available technologies or BATs) and small
systems (called small system compliance technologies) that can be used by systems
to meet the MCL. EPA evaluated the available treatment technologies and developed
cost estimates for thirteen treatment technology/residuals management combinations.
These findings were summarized in the December 2000 support document entitled
“Technologies and Costs for Removal of Arsenic from Drinking Water.”

         The treatment technology unit cost estimates are one component used to
develop national costs for the arsenic rule. Other major components include
occurrence projections, system categorization, and a compliance forecast (decision
tree). The annual compliance cost estimate for systems to meet the 10 µg/L standard
is just under $200 Million per year. This analysis is described in the December 2000
support document entitled “Arsenic in Drinking Water Rule Economic Analysis.”

        This paper will provide an overview of the process EPA used to identify
treatment technology/residuals management combinations for the final rule. It will
also discuss some additional technologies for arsenic removal that may play a
significant role in compliance with the MCL. The performance data for some of these
technologies became available after the January 22, 2001 final rule.




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




                DISPOSAL OF WASTES RESULTING FROM
                    ARSENIC REMOVAL PROCESSES


Michael J. MacPhee, Ph.D., McGuire Environmental Consultants, Inc.;
John T. Novak, Ph.D., Virginia Tech;
Rodney N. Mutter, P.E., EE&T, Inc.


        The new USEPA drinking water arsenic MCL of 10 ug/L will require
improved arsenic treatment at some locations and new treatment plants at many
others. Until recently, little attention has been given to the issue of management of
residuals from arsenic removal processes. This research showed that liquid residuals
generated by some treatment processes such as ion exchange (IX) and regenerable
activated alumina (AA) will have problems meeting state and local discharge limits.

         The research demonstrated that storage of semi-liquid or solid residuals
containing arsenic for even brief periods could result in re-release of arsenic to the
environment due to reducing conditions. Such conditions occur in landfills and other
places where residuals accumulate, including settling basins and clarifiers within
water treatment plants.
         Release of arsenic that occurred under reducing conditions was typically not
predicted by the TCLP test. In fact, all aged residuals had arsenic TCLP levels of
less than 10 times the 5 mg/L limit, but still leached appreciable quantities of arsenic.
When the same residuals were evaluated using California WET toxicity leaching test,
several were close to or exceeded the 5 mg/L limit for that state. This suggests that
utilities using coagulation (or perhaps even iron removal processes) for arsenic
removal may generate residuals that would be deemed hazardous in California. Such
a situation would have major cost and operational implications for affected utilities,
and may be a key driver for arsenic treatment process selection. The status of other
types of water treatment residuals with respect to meeting the Ca WET test is not
well known. Toxicity characterization could also have an important national cost
impact if USEPA proceeds with a review of the TCLP and makes the test more
aggressive for arsenic leaching.



CORRESPONDING AUTHOR: Michael J. MacPhee, Ph.D., McGuire
Environmental Consultants, Inc., 1620 Market Street, Suite 3E, Denver, CO
80202, USA.




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




 DEVELOPMENT OF A LOW-WASTE TECHNOLOGY FOR ARSENIC
               REMOVAL FROM WATER

József Hlavay, D.Sc., Ph.D., Mónika Szilvási, Klára Polyák, Ph.D., University of
Veszprém; János Molnár, Kornél Gruber, WEDECO Ltd.; Pál Medgyesi, Flóra
Bende, Makó Water Works; Márta Hódi, Ph.D., Hydra Ltd.


      The purification of drinking water containing inorganic arsenic compounds
causes important problems in Hungary. The new regulation of European Union sets
a limit of 10 mg As/L. Today more than 400 settlements are served with tap water
containing higher arsenic content in the country. Arsenic ions are accompanied by
high amounts of ammonium-, Fe-, and Mn-ions, humic acids (about 10-15 mg/L),
dissolved gases, and has high temperature, >30 /C. This contamination arises from
natural leaching of arsenic rocks by the percolating water. To keep this new standard
a huge effort has to be done.
      New low-waste technology was developed by combination of ion exchange and
adsorption methods. It is appropriate for selective removal of ammonium, iron,
manganese and arsenic ions, as well as humic acids from drinking water. Processes
were applied in laboratory and field experiments. Natural ion exchangers and
adsorbents were used for the experimental work as sodium-form natural
clinoptilolite, (Na-Cli), manganese-form natural clinoptilolite, (Mn-Cli), granulated
activated carbon, (GAC), and granulated Al2O3/Fe(OH)3. Optimal exhaustion-
regeneration cycles were estimated and pilot-plant set-up was designed.


CORRESPONDING AUTHOR: József Hlavay, D.Sc., PhD., Department of Earth
and Environmental Sciences, University of Veszprém, 8201 Veszprém, P. O. Box
158, Hungary, e-mail: hlavay@almos.vein.hu




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      5TH International Conference on Arsenic Exposure and Health Effects
                             SPEAKERS ' ABSTRACTS




  REPORTS FROM SOME EPA OFFICES DEALING WITH ARSENIC
                       ISSUES

Charles O. Abernathy1, Erik Winchester1, Andrew E. Schulman1, John B. Bennett1,
T. McMahon2 and Peter Grevatt3. Office of Water (OW)1, Office of Pesticides
Program (OPP)2 and Offices of Solid Waste (OSWER)3, US EPA, Washington, DC


      Arsenic (As) exposure, both natural and anthropomorphic, has affected many
people in the US and the world. Since As occurs in the water, soil and food and is
used in pesticides and industry, different Offices in the EPA are currently working
on various aspects of this problem. After considering the health effects, practical
quantitation limits, technical feasibility and cost benefits of As, the EPA promulgated
a final rule on As in drinking water on January 22, 2001. The EPA had the health
effects, treatment costs and cost benefits reviewed and on October, 30, 2001, EPA
announced that there would be no delay in implementation of the new As rule. OW
is also pursuing a more robust benefits model(s), which accounts age-specific and
phase-in of risk reductions over time following reductions in As exposure. It is also
in the process of developing a Human Health Criterion (HHC) for As. One area
requiring an new analysis is the bioaccumulation factor (BAF) for As. Although it
may bioaccumulate, primarily as organoarsenicals, in various fish and shellfish,
many of the forms seem to pose little or no health risks. Thus, the EPA is
considering the level of accumulation of various arsenicals versus the potential
toxicity of the those forms to derive a BAF for use in the As HHC. OPP held a
FIFRA Science Advisory Panel meeting in October, 2001 to consider hazard and
exposure issues related to potential risks from exposure to the inorganic As in
chromated copper arsenate (CCA)-treated lumber. The recommendations of the Panel
will be considered in completing the risk assessment currently being conducted for
inorganic As as a component of CCA-treated lumber. In addition, As is among the
most frequently identified contaminants at waste areas, including mining sites and
pesticide formulation facilities. OSWER/EPA is working in partnership with other
federal agencies and the private sector to better understand the bioavailability of As
in the contaminated soil at these sites.(The opinions expressed in this abstract are
those of the authors and do not necessarily represent the opinions or policies of the
US EPA.)

CORRESPONDING AUTHOR: Charles O. Abernathy, HECD (4304T), US EPA,
1200 Pennsylvania Ave, NW, Washington, DC 20460, USA




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