LEAD SMELTING
International Review
Nicole Fobi, MD
Internal Medicine Residency Program
Morehouse School Of Medicine
Atlanta, Georgia
Mentor:
Dr. Mary Jean Brown
Peter Kowalski, MPH
NCEH /ATSDR / CDC, Atlanta, GA
“The findings and conclusions in this presentation have not been formally disseminated by the Centers
for Disease Control and Prevention/the Agency for Toxic Substances and Disease Registry and should
not be construed to represent any agency determination or policy.”
Objectives
Background of Lead
Mining/ Smelting and environmental effects
Demographics , Statistics and Uses
Environment and Health Effects
Stakeholders and Policies/Guidelines
Recommendations
Lead in Galena
Mineral
Lead Mine pit
“Blasting operation” to form mine pit
Truck in open mine pit
Mining and Smelting
The galena is taken to a mill and
crushed in a “rod and ball”
machine
“Rod and Ball” machine
and crushed Galena
from lead mine
Large, uncovered trucks transport crushed
galena to the lead smeltering plant
– Dust flies off of truck
– Truck uses a lead-acid battery
Mining and Smelting
Crushed Galena put into suspension tank with water and
Dithiophosphate chemical
Chemical reaction creates froth, separating lead from
other ores (sulfides). Lead clings to froth which hardens
and is skimmed of resulting in 90% lead concentrate
Lead roasted, forms clumps called sinter which is melted
with coke (made from coal) and blasted with hot air
Result from chemical reaction is lead bullion
Froth flotation cell
Lead froth waiting
to be skimmed off
Statistics
Global Demand
6.98 million tonnes in 2004, 7.13 million tonnes in
2005
US largest user (1.47 million tonnes)
China next largest (1.18 million tonnes) increased
by more than 8% over 2004-5, and doubled since
2000
Rises in demand forecast for Germany, Czech
Republic and India
Statistics
Supply Sources
3.15 million tonnes from primary mining in 2004
Sources in U.S. Australia, Canada, China, Ireland,
Mexico, Peru and Portugal
Remainder from secondary recycling
Recycling rates higher for developed countries (60
to 70%) and lower for developing countries (<
30%)
Statistics
Major smelting companies:
25 smelters and refineries in
Europe, 23 in North America
and 18 in China accounted for
two-thirds of world production
in 2005
Secondary and cottage smelting companies
need to be addressed !! CRU
Uses
Environment and Health
Material leftover is
called tailings
– Tailings composed of:
. Wastewater
. Dithiophosphate
. Zinc ore
. Sulfides
– Garbage from mine
workers discarded on
landscape as well
EPA
Lead contaminating
nearby stream
Accumulation of
tailings
Waste water
Man-made lake filled with contaminated water
Environment and Health
Mining activities leave
huge holes in landscape
Holes filled in by the
mining company usually
with material containing
tailings and waste
Devastating geological effects
Environment and Health
Exposure Pathway
Current Former
Air + _
Soil + +
Water + +
Environment and Health
- Over exposure to lead is the leading cause of
workplace illness!!!!
- Lead mine/smelter workers may be exposed to lead
when:
1. Handling/cleaning the dust collection system
2. Improperly maintained collection systems
3. Settled dust in the area
4. Liquid containing lead that may have splashed onto
a worker or an object and has turned into lead dust
5. Bringing contaminated clothing home
OSHA
Occupations That Expose
Workers to Lead
– Removal of lead coatings
striping of old paint, demolition of old structures, home renovation
– Heating, machining or spraying lead products
radiator and battery repair, welding, cutting, machining,
grinding lead alloys, repair or removal of water lines using lead
piping/solder, electricians, stained glass window repair, ammunition
– Making of lead products
lead-acid battery, glaze, pottery, cable, stained glass, paint/ink, mixing
/weighing of lead powders, lead sheeting, ammunitions, glass blowing,
housing and construction
Health Consequences of
Lead Exposure
Most humans are not adequately
informed of the health risks!
Blood Lead Levels Associated with Adverse Health Effects
Lead Concentration in Blood
Children (g/dL) Adults
150
Death Encephalopathy
Nephropathy
100
Encephalopathy
Nephropathy Frank Anemia
Frank Anemia
Colic Male Reproductive Effects
50 Hemoglobin Synthesis and
Female Reproductive Effects
Hemoglobin Synthesis 40 Nerve Conduction Velocity
30
Vitamin D Metabolism Elevated Blood Pressure
Erythrocyte Protoporphyrin
20 (men)
Nerve Conduction Velocity Erythrocyte Protoporphyrin
Erythrocyte Protoporphyrin (women)
Vitamin D Metabolism(?)
Developmental Toxicity 10
IQ, Hearing, Growth
Transplacental Transfer
Note: = increased function and = decreased function. Source: ATSDR, 1992
Stakeholders
Multi-nation Organizations
NGOs
Country Health Agencies
Lead Industries
Communities
Stakeholders
In developing countries, awareness of the
public health impact of exposure to lead is
growing but relatively few of these countries
have introduced policies and regulations for
significantly combating the problem.
Stakeholders
Stakeholders need to unite and
collaborate systemically to reduce
emissions, remediate soil
contamination, and operate a
sustainable monitoring system.
WHO
Public health measures to reduce and prevent
exposure to lead :
1. Phasing out lead additives in fuels and removing
lead from petrol as soon as is practicable.
2. Reducing and phasing out the use of lead-based
paints.
3. Eliminating the use of lead in food containers.
Bulletin of World Health Organization, 2000, 78 Ref No. 0686
Environmental lead exposure: a public health problem of global dimensions
4. Identifying, reducing and eliminating lead used in
additional medicines and cosmetics.
5. Minimizing the dissolving of lead in water
treatment and water distribution Systems.
6. Improving control over exposure to lead in
workplaces.
7. Improving identification of populations at high
risk of exposure on the basis of monitoring systems.
Bulletin of World Health Organization, 2000, 78 Ref No. 0686
Environmental lead exposure: a public health problem of global dimensions
8. Improving procedures of health risk assessment.
9. Improving promotion of understanding and
awareness of exposure to lead.
10. Increasing emphasis on adequate nutrition,
health care and attention to socioeconomic
conditions that may exacerbate the effects of lead
11. Developing international monitoring and
analy-tical quality control programmes.
Bulletin of World Health Organization, 2000, 78 Ref No. 0686
Environmental lead exposure: a public health problem of global dimensions
WHO-Lead Air Quality Guidelines
Guidelines for lead in air will be
based on the concentration of lead
in blood.
A critical level of lead in blood of
100 μg/l is proposed. (based group
averages)
Chapter 6.7 Lead Air Quality Guidelines - Second Edition
WHO Regional Office for Europe, Copenhagen, Denmark, 2001 13
WHO-Lead Air Quality Guidelines
1. Currently measured baseline blood lead levels of
minimal anthropogenic origin probably range 10–30
μg/l.
2. Various international expert groups - earliest
adverse effects of lead in populations of young
children begin at 100–150 μg/l
3. Inhalation of airborne lead is a significant route of
exposure for adults but is of less significance for
young children, for whom other pathways of
exposure such as ingested lead are generally more
important.
Chapter 6.7 Lead Air Quality Guidelines - Second Edition
WHO Regional Office for Europe, Copenhagen, Denmark, 2001 13
WHO-Lead Air Quality Guidelines
4. 1 μg lead per m3 air directly contributes approx 19
μg lead per liter blood in children and about 16 μg
per liter blood in adults
5. In typical situations, an increase of lead in air also
contributes to increased lead uptake by indirect
environmental pathways - 1 μg lead per m3 air
would contribute to 50 μg lead per liter blood.
6. To prevent further increases of lead in soils and
consequent increases in the exposure of future
generations, air lead levels should be kept as low as
possible.
Chapter 6.7 Lead Air Quality Guidelines - Second Edition
WHO Regional Office for Europe, Copenhagen, Denmark, 2001 13
WHO-Lead Air Quality Guidelines
7. Efforts be made to ensure that at least 98%
of an exposed population, have blood lead
levels that do not exceed 100 μg/l.
- The median blood lead level would not
exceed 54 μg/l.
- The annual average lead level in air should
not exceed 0.5 μg/m3.
- This proposal is based on the assumption
that the upper limit of non-anthropogenic
lead in blood is 30 μg/l.
Chapter 6.7 Lead Air Quality Guidelines - Second Edition
WHO Regional Office for Europe, Copenhagen, Denmark, 2001 13
WHO-Lead Air Quality Guidelines
LOAEL : lowest observed adverse effect levels
ALA: Delta Aminolevulinic Acid Dehydrate
FEP: Free Erythrocyte Protoporphyrin
World Bank
Lead and Zinc Smelting: Industry sector guidelines
The key production and control practices that will lead to compliance
with emissions requirements :
1. Give preference to the flash-smelting process where appropriate.
2. Choose oxygen enrichment processes that al-low higher SO2
concentrations in Smelter gases to assist in sulfur recovery, use the
double-con-tact, double-absorption process.
3. Improve energy efficiency to reduce fuel us-age and associated
emissions; use low NOx burners; give preference to natural gas as
fuel.
Pollution Prevention and Abatement Handbook
WORLD BANK GROUP Effective July 1998
World Bank
Lead and Zinc Smelting: Industry sector guidelines
4. Reduce air emissions of toxic metals to acceptable levels.
5. Maximize the recovery of dust and minimize fugitive missions;
use hoods and doghouse enclosures.
6. Reduce effluent discharge by maximizing wastewater
recycling.
7. Avoid contamination of groundwater and surface waters by
leaching of toxic metals from tailings, process residues, slag,
and other wastes.
Pollution Prevention and Abatement Handbook
WORLD BANK GROUP Effective July 1998
World Bank
Monitoring:
Air Emissions
Liquid affluent
Solid Wastes
Ground water
Surface water
World Bank
Emissions Effluents
Parameter Maximum value Parameter Maximum value
Sulfur dioxide 400 pH 6–9
Arsenic 0.1 TSS 20
Cadmium 0.05 Arsenic 0.1
Copper 0.5 Cadmium 0.1
Lead 0.5 Copper 0.5
Mercury 0.05 Iron 3.5
Zinc 1.0 Lead 0.1
Particulates 20 Mercury 0.01
Zinc 2.0
Total metals 5
Temperature increase less than 3
(milligrams per normal cubic meter)
World Bank
Monitoring data should be analyzed and reviewed at
regular intervals and compared with the operating
standards
Records of monitoring results should be kept in an
acceptable format.
The results should be reported to the responsible
authorities and relevant parties as required
Pollution Prevention and Abatement Handbook
WORLD BANK GROUP Effective July 1998
World Bank
Environmental, Health, and Safety Guidelines
BASE METAL SMELTING AND REFINING
Environment
Occupational health and safety
Community health and safety
Construction and decommissioning
Performance indicators and monitoring
APRIL 30, 2007
World Bank Group
ILZRO
The INTERNATIONAL LEAD ZINC RESEARCH ORGANIZATION
Sponsors include most of the major producers of lead, zinc
and silver
ILZRO's R&D portfolio for 2007 encompasses the primary
applications of lead, zinc and silver, as well as significant work
in the areas of the environment and human health.
The results of ILZRO R&D efforts are communicated through
a variety of forums, including research reports, technical
seminars, expert consulting, internet sites and printed
publications.
ILZSG
The International Lead and Zinc
Study Group
Represents one of the few
international forums for the lead and
zinc business where Governments and
Industry can exchange views on the
consequences of international
environmental and health related
initiatives on the trade in lead and
zinc.
ILZSG
The ILZSG's Economic and Environment Committee follows all
environmental aspects relevant to lead and zinc mines and smelters
and end uses which entails:
• monitoring of environmental issues
• Informing Study Group member countries on particular issues
relating to
- ecotoxicity
- transboundary movements of waste
- transboundary air pollution
- international co-ordination of activities on chemicals
ILZSG has already released environmental studies such as
"Environmental and Health Controls on Lead”
ILMC
International Lead Management Center
The international lead industry is committed, through
the ILMC to work with governments, industries and the
international community to manage the risk of
lead exposure.
ILMC complements and supports existing international
risk management activities and responds to the
individual needs of countries who wish to introduce
such projects in either industry or their local
communities.
ILMC
Sponsors:
• Aberfoyle Ltd., Australia
• ASARCO, Inc., United States of America
• Boliden, Sweden
• Cominco Ltd., Canada
• Doe Run Company, United States of America
• Met-Mex Pen˜oles S.A. de C.V., Mexico
• Mount Isa Mines Holdings, Australia
• Noranda Mining and Smelting, Inc., Canada
• Pasminco Ltd., Australia
• Union Miniere, Belgium
ILMC
Action Programs :
• Lead mining, smelting, refining and recycling
• Occupational and public health
• Risk reduction programs
• Technology transfer
• Social policy and economic issues
Activities of The ILMC
1. Pilot Programs (e.g.. Philippines, Mexico, Russia, Peru)
2. Risk Management Teams
3. Worker Health and Hygiene Training Programs
4. Outreach To Consumer Industries
5. Information Resources and Databases
6. Internet Services
7. News Casting
8. Product and Application Information
LDAI
Lead Development Association International
LDAI is dedicated to encouraging
the responsible use of lead and
its compounds
LDAI - Objectives
1. Promote the responsible use of lead throughout its life cycle
2. Increase lead's competitiveness with alternative materials
3. Provide cost-effective co-ordination of sustainable initiatives for the benefit
of the lead industry and society
4. Contribute to the identification of appropriate ways to manage risks to
health or the environment attributable to lead
5. Address legislative or other scientific issues which may affect the lead
industry
6. Communicate with members and with outside parties as appropriate on
issues of relevance to the lead industry.
The Green Lead Initiative
The Green Lead Initiative
Lead acid batteries account for about 75% of lead
consumption.
Green Lead Program would direct all sectors in the
life cycle of a Lead Acid Battery, ( the Mines, the
Smelters, the Battery manufacturers, Consumers and
the Recyclers) in practices and procedures that
minimize or negate any potential adverse impacts on
either the environment or the population.
The Green Lead Initiative
Those working in the informal sector will either get out of the
ULAB business or become legitimate collectors of ULAB.
Green Lead regime has tremendous potential in the developing
world (already in Salvador, Philippines and Venezuela ) as model
to assist in the elimination of poor recovery practices.
The Green Lead initiative, once in place, will facilitate the
development of environmentally sound practices, safe working
conditions and create a level of product stewardship at the
forefront of any commodity.
London Workshop
April 2005.
The Green Lead Initiative
Green Lead™ Standards Currently Available
1. Medical surveillance – Blood Leads
2. Solid Waste Management
3. Effluent treatment and discharges
4. Emission Control Systems
5. ULAB Collection, transport and shipping
6. Battery Labels
7. Public Communications and awareness
8. Site Sustainability
9. Community Outreach
London Workshop
April 2005.
The Green Lead Initiative
Certification Standards
Biological Monitoring and Medical Surveillance
• Lead smelting, ULAB and scrap recovery, refining, alloying and casting
• Lead-acid battery manufacture and breaking
• Manufacturing lead compounds, including pigments and colors.
• working with metallic lead and alloys containing lead, e.g. soldering
• Manufacturing leaded-glass and certain ceramics
• Some painting of buildings; some spray-painting of vehicles
• Hot cutting in demolition and dismantling operations
• Certain jewelry and badge enameling techniques
London Workshop
April 2005.
Summary
1. The demand for Lead is increasing worldwide
2. Communities are still exposed to lead from present and
past mining and smelting activities worldwide (esp. in
developing countries)
3. Communities need to be educated about exposure and
health effects of Lead
4. Multi-national companies appear to be taking some
positive steps but more needs to be done to prevent
continuous exposure
Summary
Stakeholders need to unite and
collaborate systemically to reduce
emissions, remediate soil
contamination, and operate a
sustainable monitoring system.
Summary
Because of their experience, many
international bodies are well equipped
to provide assistance with tackling the
various dimensions of exposure to
lead in the environment.
Summary
Screening, monitoring, intervention and evaluation
are critical for the development of rational, cost-
effective and science-based public health policies
aimed at achieving these goals.
Success in this endeavor requires government
commitment, incentive policies, a broad
consensus among stakeholders and public
understanding, acceptance and support
Acknowledgements
Mentors:
Dr Mary Jean Brown
Peter Kowalski, MPH
Jerome Carter, PhD
George Prince
Erica Brantley, MSA
Carla Durham, EMRP Program coordinator
ATSDR / CDC & Association of Minority Health
Professions Schools, INC.