HEAVY METALS CONTAMINATION IN DAVAO REGION by yhz16267

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									HEAVY METALS CONTAMINATION IN
        DAVAO REGION


                   Ed. B. Prantilla*
                          and
                 Carmelita Martinez **
 *RECORD Foundation and School of Applied Economics, USEP
 **School of Government and Management, USEP
Introduction

 The relevance of heavy metals
 contamination in Davao Region to
 Caraga Region is due to the fact that
 Naboc River, which drains the gold rush
 area at Diwalwal, is a tributary of
 Agusan River. The Diwalwal gold rush
 area uses about 6 metric tons of
 mercury annually.
Objectives of the Study

 Using available monitoring reports and
 studies, present a consolidated report
 on:
 The extent of heavy metals
 contamination of rivers and lake in
 Davao Region.
Objectives (cont’d)

 Extent of heavy metals contamination
 of fish and shellfish in Davao Gulf and
 in Lake Leonard.
 Effects of mercury contamination in
 human population, and
 Recommends possible actions.
Sources of Heavy Metals
Contamination in Davao Region

  Mercury – mainly from gold processing:
  Estimated annual mercury consumption
  by gold rush area:
Diwalwal --- 5,724 kgs.
Boringot ---- 720 kgs.
Biasong ---- 600 kgs.
Diat --------- 2,388 kgs.
Sources of heavy metals
contamination (cont’d)
Panganason ----- 588 kgs.
Gumayan -------- 1,980 kgs.
Bango ------------ 888 kgs.
Lumanggang, Maco – 84 kgs.
Lumanggang, Pantukan – 252 kgs.
Inopuan-Saravan -------- 300 kgs.
Total annual Hg consumption = 13,524 kgs.
Source of Basic Data: MGB, DENR XI
Sources of heavy metals
contamination (cont’d)

 Lead – possible sources are from the
 natural deposits of this metal in rocks
 leached through weathering process
 and from small-scale mining.
 Cadmium – same as lead.
Extent of heavy metals
contamination in rivers and lake
 Naboc River – A tributary of Agusan River,
 heavily contaminated with mercury. Water in
 all nine sampling stations reported mercury
 contents much higher that standard set by
 DAO 34 for Class C water in 2006. Lead
 content of 5 out of 9 sampling stations
 registered lead content higher that standard
 set by DAO 34. Cadmium content below
 critical level for Class C water.
Extent of heavy metals contamination in
rivers and lake (cont’d)

  Kingking River – Discharges directly to
  Davao Gulf. Six (6) sampling stations
  registered mercury content higher that
  the standard set by DAO 34 for Class C
  water in 2006. Cadmium is below
  critical level, but lead registered high
  level over the standard in 2004 for all 6
  sampling stations. Lead analysis is not
  available for 2006.
Extent of heavy metals contamination in
rivers and lake (cont’d)

  Hijo River – Mercury content of water
  from 9 sampling stations exhibited
  below critical level for Class C water in
  2005. No sediment study conducted.
  Lead content of water was very high in
  sampling stations 4 to 9 in 2001 and in
  6 to 9 in 2003. Below critical level from
  2004 to 2005 in all sampling stations.
Extent of heavy metals contamination in
rivers and lake (cont’d)

  Matiao River – Water from one
  sampling station registered mercury
  content higher that the limit set by DAO
  34 in 2006. Cadmium content below the
  limit, lead analysis is not available.
Extent of heavy metals contamination in
rivers and lake (cont’d)

  Batoto River – Mercury content of water
  from 6 sampling stations exhibited
  mercury content below the limit set by
  DAO 34. No analysis for lead and
  Cadmium available.
Extent of heavy metals contamination in
rivers and lake (cont’d)

  Masara River – Water monitoring
  reports cover only lead and cadmium.
  Cadmium content was below the limit
  set by DAO 34. Lead content of water
  from 7 stations in 2005 gave an
  unambiguous result, i.e. they could be
  higher or lower than the limit set by
  DAO 34.
Extent of heavy metals contamination in
rivers and lake (cont’d)

  Manat River – the 2005 available report
  showed that cadmium, lead and
  mercury content of water from 6
  sampling stations were all below the
  limits set by DAO 34.
Extent of heavy metals contamination in
rivers and lake (cont’d)

  Lake Leonard – water samples from 12
  stations revealed the following: Hg
  below critical level; Pb beyond critical
  level in 2001, and Cd beyond critical
  level for stations 3, 5, 7 and 10. Soil
  samples registered Pb content beyond
  tolerable level in all stations; Cd in
  stations 7, 8, 9, 10 and 12.
Extent of heavy metals contamination in
rivers and lake (cont’d)

  Lake Leonard (cont’d) – an analysis of
  fish captured in the lake in 2001
  showed lead, cadmium and copper
  contents higher than the critical
  tolerable limits (standard used was EU
  guidelines for fish).
Mercury in Davao Coastal Waters

The 1982 study:
 Mercury content of coastal waters from
 Godo and Guinoo were highest during
 the Month of June. Tibungco coastal
 water has the highest mercury content
 in the Month of July.
Mercury in Davao Coastal Waters
(cont’d.)

 The 1982 study (cont’d)
 Mercury levels in Fish – found mercury
 levels in Tangigue; Barilis; Tulingan;
 and Diwit exceeded the 0.500 ppm limit
 set by WHO.
Mercury in Davao Coastal Waters
(cont’d)

 The 1982 study (cont’d):
 Mercury level in Shellfish – Hg level in
 shellfish caught in Tibungko (Anadara
 cepoides; Gafrarium tumidium;
 Terebralia sp.; Turbo sp.; Nerita sp.)
 have mercury content higher than the
 limit set by WHO.
Mercury in Davao Coastal Waters
(cont’d.)

 Mercury levels in shellfish (cont’d) –
 shellfish (Tivela sp.) caught at Bucana,
 and shellfish (Haliotis sp.) caught at
 Godo registered mercury content higher
 than the limit set by WHO.
Mercury in Davao Coastal Waters
(cont’d.)

 The DOH XI study (2006):
 Examined fish samples from Davao del
 Sur, Davao Oriental and Davao City
 markets and found out that “talakitok;
 “mayamaya”, “bariles” and “malasugue”
 have methyl mercury content higher
 than the allowable limit of 0.3 micro
 gram per gram.
Mercury Levels in Human Population

 The Maramba and Dablo 1996 study:
 Examined 114 school children with ages
 ranging from 5 to 15 years all residents
 of Apokon, Tagum City. Results showed
 24 school children with elevated Hg
 blood levels more than 10 ppb, and 13
 school children with urinary Hg levels
 more than 5 ppb.
Mercury Levels in Human Population
(cont’d)

 The Maramba-Dablo study (cont’d):
 Examined 70 miners, field health
 personnel and residents in Diwalwal,
 results of laboratory analysis showed 6
 respondents with blood mercury levels
 greater than 20 ppb, and 3 respondents
 with urinary mercury levels greater than
 50 ppb.
Mercury Levels in Human Population
(cont’d)
  The DOH XI study (2006)
  Total blood mercury level ranges from 3.51
  to 299.99 micro gram per liter with an
  average of 21.44 micro gram per liter.
  Forty-five individuals or 60% of those
  individuals directly involved in gold mining
  were found to have high levels of mercury
  at more than 15 ug/L while three individuals
  or 12% of those with no direct exposure
  were also found to have high levels of
  mercury at more than 15 ug/L.
Mercury in Pregnant Women

 The Ramirez, et al studies (2000,
 2003): The study was conducted at
 Apokon, Tagum City. Observed that
 “the problem of exposure to Hg in this
 area is particularly serious for the
 pregnant women because there are no
 barriers to the transfer of Hg from the
 mother to the fetus”
Mercury in Pregnant Women (cont’d)
 The Ramirez, et al study (2000, 2003)
 (cont’d): The study showed: “The
 prevalence of Hg in the fetal
 compartments was higher than in the
 maternal fluid compartments. Hg was
 present in 6.4% of maternal blood and
 6.4% of breast milk, as compared with
 16.7% of cord blood, 31.6% of infants'
 hair, and 46.1% of meconium.”
Mercury in Pregnant Women (cont’d)
 The Ramirez, et al study (2000, 2003)
 (cont’d): Regression analysis showed Hg
 levels in meconium to be correlated with
 prevalence of Hg in infants' hair, length of
 stay in Tagum, and meconium-stained
 amniotic fluid. Fisher's Exact probability test
 showed that the prevalence of Hg in
 meconium was significantly related to the
 prevalence of Hg in the mothers' blood and
 length of stay in Tagum:
Mercury in Pregnant Women (cont’d)
 The Ramirez, et al study (2000, 2003)
 (cont’d): “The prevalence of Hg in cord blood
 was significantly related to the prevalence in
 the mothers' blood. Regression analysis of
 levels of Hg in cord blood showed a
 significant relation to levels in mothers' blood
 (.0001), prevalence in infants' hair (.0126),
 gestational age (GA) (.0091), and head
 circumference (HC) (.0469)”
Mercury in Pregnant Women (cont’d)

 The Ramirez, et al study (2000, 2003)
 (cont’d): The 2000 study concluded that
 “Adverse effects may not be evident at
 birth but sub-clinical toxicity of the fetus
 is a possibility. Therefore, long-term
 developmental and neurobehavioral
 assessments are needed”
Mercury in Pregnant Women
(cont’d)
 The Ramirez, et al follow-up 2003
 study:
 The study used 47 of the original
 infants from Tagum and 88 infants of
 the same age from Sarangani as
 control. The tests used are: cognitive
 adaptive test and clinical linguistic
 auditory milestone scale (CAT/CLAMS)
Mercury in Pregnant Women
(cont’d)
 The Ramirez, et al follow-up 2003 study
 (cont’d): The following were found higher in
 the control group compared to Tagum infants
 (a) expressive language quotient; (b) CLAMS,
 and (c) Full-scale developmental quotient.
 Fifteen percent of Tagum infants had global
 delay (full-scale developmental quotient).
Mercury in Pregnant Women
(cont’d)
 The Ramirez, et al follow-up 2003 study
 (cont’d): The study concluded that “that
 prenatal Hg exposure is correlated with
 lower scores in neuro-developmental
 screening, but more so in the linguistic
 pathway. Other confounding factors
 cannot be eliminated”.
Recommendations
  Strict control should be imposed on
  the use of mercury and other heavy
  metals in the region. This include
  registration of users, the monitoring of
  amount of heavy metals used per day
  by establishments, approved
  safeguards and control/management
  and disposal of mine tailings or
  effluents.
Recommendations (cont’d)

  Eradication of illegal trade of mercury
  in the region. Mercury could only be
  used by licensed users with the
  government imposing strict
  compliance with environmental laws
  concerning the use of mercury.
Recommendations (cont’d)
  The use of mercury in gold processing is
  prevalent only with small scale miners or
  artisanal miners. If the government will opt
  therefore to maintain the operation of small
  scale or artisanal mining, it should impose a
  condition that small scale or artisanal
  miners should use an alternative gold
  extraction technology that does not involve
  mercury.
Recommendations (cont’d)
  The presence of high mercury level in the rivers of
  Compostela Valley province needs immediate
  attention, not only in controlling or completely
  stopping the use of mercury in the mining areas of
  the province, but also to determine the extent of
  the damage suffered by the environment and the
  affected population. Accordingly, appropriate
  remediation process should be undertaken by the
  government including the compensation of the
  population whose health have been compromised
  or affected by mercury contamination.
Recommendations (cont’d)
  Government action on the presence of high levels
  of mercury in certain species of fish caught in
  Davao Gulf is long overdue. This inaction of the
  government may have very serious health
  implications because those fishes with high level of
  mercury are eaten by a large portion of the Davao
  Region population. It is therefore recommended
  that the government immediately warn the public
  about the danger of eating Tangigue, Barilis,
  Tulingan, Diwit, Talakitok, Mayamaya, and
  Malasugui.
Recommendations (cont’d)
  A study which compared two year infants whose
  mothers were exposed to mercury in Tagum City
  with that of a control group showed that prenatal
  mercury exposure is correlated with lower scores in
  neuro-developmental screening, but more so in the
  linguistic pathway. This study has serious
  implications on the future human resource
  capabilities of the region. It is recommended that
  an expanded study should be conducted to include,
  among others, the incidence of autism which is
  related to mercury poisoning in other countries.
Recommendations (cont’d)
  The studies conducted so far on heavy
  metals contamination in the region do not
  include sediment analysis, heavy metals in
  aquifers, and presence of heavy metals in
  plants and fresh water fish and farm
  animals. This situation should be
  immediately remedied in order to map out
  the short and long-term response of the
  government to heavy metals pollution in the
  region.
Recommendations (cont’d)
  It has been observed that the population at large is
  inadequately informed on the dangers of heavy
  metals pollution and in particular the effect of
  mercury on the health status of a person. It is
  therefore recommended that a broad-based
  intensive information, education and
  communication program be formulated and
  implemented by the local government units and
  national government agencies, the academe and
  non-government organizations in the region.
Recommendations (cont’d)
 The government should impose a condition that
 polluters should pay for the damage they have
 incurred on the environment and on human
 population. In view of the possibility of large scale
 health degradation of human population exposed to
 mercury pollution in the region, the government
 should also seriously consider imposing an
 appropriate pollution tax to miners and gold
 processors to pay for those whose health have been
 impaired and for the economic cost of polluting the
 sea and water system of the region
Recommendations (cont’d)
  An expanded study should be conducted on
  heavy metals contamination of fish and
  shellfish in the Davao Gulf and in freshwater
  fish in rivers and lakes of the region. This
  study will validate and update the past
  studies and provide policy makers the
  current status and extent of heavy metals
  contamination in the food chain.
Recommendations (cont’d)

  Include heavy metals as priority
  parameter in calculating wastewater
  discharge fee.
END OF PRESENTATION




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