Presented by
Internal Medicine Residency Program
Morehouse School of Medicine, Atlanta, GA
May 15 th , 2007
Mary Jean Brown, PhD
Peter Kowalski, MPH
NCEH/ATSDR/CDC, Atlanta, GA

Lead is the most abundant of the heavy metals in the Earth’s crust. It has been used since prehistoric times, and has become widely distributed and mobilized in the environment. Exposure to and uptake of this non-essential element have consequently increased. Both occupational and environmental exposures to lead remain a serious problem in many developing and industrializing countries, as well as in some developed countries. In most developed countries, however, introduction of lead into the human environment has decreased in recent years, largely due to public health campaigns and a decline in its commercial usage, particularly in petrol. Acute lead poisoning has become rare in such countries, but chronic exposure to low levels of the metal is still a public health issue, especially among some minorities and socioeconomically disadvantaged groups. At high levels of human exposure there is damage to almost all organs and organ systems, most importantly the central nervous system, kidneys and blood, culminating in death at excessive levels. The demand for Lead is steadily increasing world wide. Many communities are still exposed to lead from past and present lead smelting activities.
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. Much work needs to be done to identify and treat children with elevated blood lead levels and reduce lead exposure in the community. 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.
This article reviews the nature and importance of environmental exposure to lead
in developing and developed countries as well as policies and guidelines
from Stakeholders.

Lead metal is described as being either primary or secondary. Primary lead is produced directly from mined lead ore. Secondary lead is produced from scrap lead products which have been recycled.
The most common lead ore is galena or lead sulphide. Other elements frequently present include zinc and silver. In fact lead ores constitute the main sources of silver, contributing substantially towards the world's total output.
Lead is obtained from galena by a process called smelting. This involves roasting the ore to remove the sulphur and to obtain lead oxide which is then reacted with coke in a furnace. The resulting lead bullion contains many impurities such as silver and gold
(hence the name bullion) as well as antimony, arsenic, copper, tin and zinc. These impurities are then removed by various refining steps to obtain pure lead.
The process is extremely costly financially and to the environment.
A typical primary lead smelting and refining

Lead in Galena
Lead Mine pit
Blast operation to form mine pit

Galena is taken to a mill and crushed in a rod and ball machine
Crushed Galena from lead mine

Large, uncovered trucks transport crushed galena to the lead smelting plant
Crushed galena put in suspension tank with water and dithiophosphate chemical. Chemical reaction creates froth separating lead from ores (sulfides). Lead clings to froth which hardens and is skimmed off resulting in 90% lead concentrate

Around 3 million tonnes of lead are mined in the world each year. Lead is found all over the world but the largest mining countries are Australia, China and the United States, which between them account for more than 50% of primary production.
United States
Australia
Canada
China
India
Ireland
Kazakhstan
Mexico
Morocco
Peru
Poland
South Africa
Sweden
48
42
61
Other countries 198
World total (rounded) 3,270
Mine production
2005 2006
426
776
430
780
73
1,000
58
64
44
130
31
319
79
1,050
60
65
55
140
42
320
60
50
61
170
3,360
US Geological Survey, Mineral Commodity Summaries, January 2007
Data in thousand metric tons of lead content
Top Mining Countries Largest Lead Producers
Australia
China
USA
Peru
Mexico
654,000
618,000
464,000
308,000
152,000
China
USA
Germany
UK
Australia
1,533,000
1,338,000
352,000
338,000
304,000
Major Users of Lead
USA
China
Germany
Korea Rep
UK
1,488,000
1,050,000
392,000
342,000
330,000
Main Recyclers of Lead
USA
Germany
Japan
UK
Italy
1,098,000
222,000
190,000
176,000
153,000
Reserves
8,100
15,000
2,000
11,000
NA
NA
5,000
1,500
500
3,500
NA
400
500
19,000
67,000
Reserve base
20,000
28,000
9,000
36,000
NA
NA
7,000
2,000
1,000
4,000
5,400
700
1,000
30,000
140,000
KEY WORLD STATISTICS 2003 (Values shown in tones)

Lead –Major Uses
Batteries largest use by far (78%) for motor vehicles and back up power generators
Lead compounds (8%)
–petrol anti-knock additives
–stabilizers for PVC, crystal glass, ceramic glazes
–pigments
Rolled sheets for construction (5%)
Use of lead in petrol has been largely discontinued and is being phased out where use continues
Material left over after mining is called tailings which are composed of waste water, dithiophosphate, zinc ore and sulfides. Garbage from mine workers is discarded on landscape as well. Tailings accumulate and are dumped along with waste water into tailing ponds. Heavy metals and chemicals leech into the soil and migrate into the water supply especially when it rains. The amount of waste dumped into pond could be outrageous. Doe
Run Mine alone in 1998 generated 4.9 million metric tons of process water into unlined surface impoundments. Even after mine/smelters close waste continue to contaminate the land and remains a source of exposure in the community. This leads to tremendous geological damage. Contaminated water flows into streams and wells. Animals drink the water, humans use it for recreation and fishing. The aquatic life becomes contaminated.

Leftovers called tailings
Lead contaminating nearby system

Waste water
Man-made lake filled with contaminated water

Health consequences are more devastating in children especially those less than 6yrs of age. They are more exposed as a result of picking up lead from playgrounds/soil and ingesting (hands to mouth). Even trace amounts can damage a child’s still developing body (affects nervous system, stunt growth, attention span, behavioral problems etc).
Fetuses exposed suffer low birth weight and altered gestation age.

These include multinational organizations (e.g. WHO, World bank), NGOs, country health agencies, lead industries and communities.
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.
Much work needs to be done to identify and treat children with elevated blood lead levels and reduce lead exposure in the community. 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.
The most immediate priority is to reduce exposure to lead and other contaminants. This is best accomplished by building the environmental public health infrastructure needed to develop and implement a comprehensive and integrated intervention plan. Stakeholders need to unite and collaborate systemically to reduce emissions, remediate soil contamination, and operate a sustainable monitoring system
Public health measures to reduce and prevent exposure to lead by reducing the use of the metal and its compounds and by minimizing lead-containing emissions that result in human exposures. This can be achieved by:
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.
4. Identifying, reducing and eliminating lead used in traditional 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.
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 analytical quality control programmes (36).
Environmental lead exposure: a public health problem of global dimensions
Bulletin of World Health Organization, 2000, 78 Refs No. 0686

Lead Air Quality Guidelines
Guidelines for lead in air will be based on the concentration of lead in blood. Critical effects to be considered in the adult organism include elevation of FEP, whereas for children cognitive deficit, hearing impairment and disturbed vitamin D metabolism are taken as the decisive effects. All of these effects are considered adverse. A critical level of lead in blood of 100 μg/l is proposed. It should be stressed that all of these values are based on population studies yielding group averages, which apply to the individual child only in a probabilistic manner.
1. Currently measured “baseline” blood lead levels of minimal anthropogenic origin are probably in the range 10–30 μg/l.
2. Various international expert groups have determined that the earliest adverse effects of lead in populations of young children begin at 100–150 μg/l. Although it cannot be excluded that population effects may occur below this range, it is assumed to be prudent to derive a guideline value based on the lowest value of this range (100 μg/l).
3. It can be assumed that inhalation of airborne lead is a significant route of exposure for adults (including pregnant women) but is of less significance for young children, for whom other pathways of exposure such as ingested lead are generally more important.
4. It appears that 1 μg lead per m3 air directly contributes approximately 19 μg lead per liter blood in children and about 16 μg per liter blood in adults, although it is accepted that the relative contribution from air is less significant in children than in adults. These values are approximations, recognizing that the relationships are curvilinear in nature and will apply principally at lower blood lead levels.
5. It must be taken into account that, in typical situations, an increase of lead in air also contributes to increased lead uptake by indirect environmental pathways. To correct for uptake by other routes as well, it is assumed that 1 go lead per m3 air would contribute to
50 μg lead per liter blood.
6. It is recommended that efforts be made to ensure that at least 98% of an exposed population, including preschool children, have blood lead levels that do not exceed
100 μg/l. In this case, the median blood lead level would not exceed 54 μg/l. On this basis, 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. These estimates are assumed to protect adults also.
7. 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.
Since both direct and indirect exposure of young children to lead in air occurs, the air guidelines for lead should be accompanied by other preventive measures. These should specifically take the form of monitoring the lead content of dust and soils arising from lead fallout. The normal hand-to-mouth behavior of children with regard to dust and soil defines these media as potentially serious sources of exposure. A specific monitoring value is not recommended. Some data indicate that lead fallout in excess of 250 μg/m² per day will increase blood lead levels.
Chapter 6.7 Lead Air Quality Guidelines - Second Edition
WHO Regional Office for Europe, Copenhagen, Denmark, 2001 13

Lead and Zinc Smelting – Industry Sector Guidelines
Key Issues
The key production and control practices that will lead to compliance with emissions requirements can be summarized as follows:
1. Give preference to the flash-smelting process where appropriate.
2. Choose oxygen enrichment processes that allow 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 usage and associated emissions; use
Low NOx burners; give preference to natural gas as fuel.
4. Reduce air emissions of toxic metals to acceptable levels.
5. Maximize the recovery of dust and minimize fugitive emissions; 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.
Monitoring and Reporting
Frequent sampling may be required during startup and upset conditions. Once a record of consistent performance has been established, sampling for the parameters listed in this document should be as described below.
Air emissions should be monitored continuously for sulfur dioxide and particulate matter.
Other air emissions parameters should be monitored monthly. Fugitive emissions should be monitored annually.
Liquid effluents should be monitored daily for pH and total suspended solids and at least weekly for all other parameters.
All solid waste, tailings, and leachates should be monitored for toxic metals. Contamination of groundwater and surface waters should be avoided.
Monitoring data should be analyzed and reviewed at regular intervals and compared with the operating standards so that any necessary corrective actions can be taken. 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

Environmental, Health, and Safety Guidelines
Base Metal Smelting and Refining
1. Environmental
1.1 Air Emissions and Ambient Air Quality
1.2 Energy Conservation
1.3 Wastewater and Ambient Water Quality
1.4 Water Conservation
1.5 Hazardous Materials Management
1.6 Waste Management
1.7 Noise
1.8 Contaminated Land
2. Occupational Health and Safety
2.1 General Facility Design and Operation
2.2 Communication and Training
2.3 Physical Hazards
2.4 Chemical Hazards
2.5 Biological Hazards
2.6 Radiological Hazards
2.7 Personal Protective Equipment (PPE)
2.8 Special Hazard Environments
2.9 Monitoring
3. Community Health and Safety
3.1 Water Quality and Availability
3.2 Structural Safety of Project Infrastructure
3.3 Life and Fire Safety (L&FS)
3.4 Traffic Safety
3.5 Transport of Hazardous Materials
3.6 Disease Prevention
3.7 Emergency Preparedness and Response
4. Construction and Decommissioning
4.1 Environment
4.2 Occupational Health and Safety
4.3 Community Health and Safety
World Bank Group, April 2007
- The International Lead Zinc Research Organization
ILZRO's sponsors include most of the major producers of lead, zinc and silver, and significant numbers of end-users of these metals from among the steel, automotive, die casting, battery, galvanizing and other industries.
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.

- The International Lead Zinc Study Group
The International Lead and Zinc Study Group (ILZSG) is an intergovernmental organization which regularly brings together twenty-eight member countries in an international forum to exchange information on lead and zinc. ILZSG provides a unique and globally recognized source of industry statistics and organizes twice yearly meetings between producing and consuming countries, industry and government representatives.
The International Lead and Zinc Study Group (ILZSG) represents one of the few international forums for the lead and zinc business where Governments and Industry can exchange views through its Economic and Environmental Committee and its Secretariat, on the consequences of international environmental and health related initiatives on the trade in lead and zinc. Moreover, the ILZSG Secretariat may attend committee meetings of relevant international organizations such as the OECD, the European Commission and the World Bank, as well as private industry associations.
The ILZSG's Economic and Environment Committee follows all environmental aspects relevant to lead and zinc mines and smelters and end uses. This 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 2007"
- The International Lead Management Center
The ILMC, LLC, is a lead risk reduction project administered by the International Lead
Zinc Research Organization (ILZRO).
The international lead industry recognizes that exposure to lead can result in risk to human health and the environment. The industry is committed, through the International Lead Management Center (ILMC), to work with governments, industries and the international community to manage the risk of lead exposure.
The International Lead Management Center is thus charged with the implementation of a voluntary Industry Lead Management Project.
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.
The Center welcomes inquiries and requests for either advice or assistance.
The Center is sponsored by the following major mining and lead-producing corporations:
• 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
Guidance and direction on priorities, project feasibility and action programs are provided by a Policy Advisory Group that includes independent experts with international experience and expertise in:
• Lead mining, smelting, refining and recycling
• Occupational and public health
• Risk reduction programs
• Technology transfer
• Social policy and economic issues
Activities of the ILMC
Pilot Programs
ILMC will assist and cooperate with government agencies interested in assessing and reducing the risk of lead exposure.
These Pilot Programs address distinct lead exposure issues unique to each country’s cultural, technical, geographic and socio-economic circumstances
Pilot Programs:
ILMC and the Philippines
ILMC and Mexico
ILMC and Russia
ILMC and Peru
Risk Management Teams
When ILMC receives a request for assistance from a government agency or industry sector wishing to initiate a lead risk management program, a “Risk
Management Team” will be assigned to collect, collate and analyze all the available data.
Worker Health and Hygiene Training Programs
Good operating practices and hygiene procedures are the most important factors in reducing occupational lead exposure. Experience has shown that those companies with the lowest levels of exposure have invariably the highest operating standards and the best hygiene procedures.
Outreach To Consumer Industries
ILMC has established liaison with relevant industry and consumer organizations in order to ensure a cooperative approach to minimize exposure
Information Resources and Databases
ILMC has established an extensive database covering such issues as:
• International inventory of standards and best practice - for
occupational exposure
• Occupational and environmental case studies - for risk
management projects
• Usage, properties, risks and options - for lead bearing products

• International inventory of standards and control - for industrial
emissions
• Research results assessing risk reduction benefits - for exposure
reduction
• Exposure assessments and environmental sampling - for
abatements
• Material collection systems, recycling technology - for recycling
• Community-based risk management programs - an inventory of
risk reduction experience
Internet Services
Information is available electronically on the Internet at http://www.ILMC.org on the following:
• Risk Management and Control Protocols
• Environmental Management Systems
• International Lead Exposure Standards
• Testing Methods and Procedures
• Product Definitions
• Codes of Practice
• News Casting
• Pilot Programs
• Fact Sheets
• Diary of ILMC Activities
• An electronic inquiry and comment hotline to the ILMC office.
News Casting
News Casting is the quarterly bulletin of ILMC and features articles covering all the international activities of the Center.
There are regular Pilot Program updates and features explaining the role and achievements of the lead industry’s voluntary risk management strategy.
Product and Application Information
Risk Management Information for products and applications are available for the following:
• Ceramics - Pottery and Glass
• Communication and Power Cables
• Fishing Sinkers
• Lead Coatings, Piping and Sheet
• Lead Pigments - including paints and children’s toys
• Lead Shot
• Lead Solder – food cans and electronics
• Leaded Gasoline
• Life Cycle Inventory for Lead-Acid battery
• Miscellaneous - including modeling and wheel weights
• Noise Insulation
• Plumbing
• Radiation Shielding
• Stabilizers

- Lead Development Association International
LDAI is dedicated to encouraging the responsible use of lead and its compounds.
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.
As lead acid batteries account for about 75% of lead consumption, it seemed logical to initially focus on the stewardship of lead acid batteries.
In principle, this means that a Green Lead Program would direct all sectors in the life cycle of a Lead Acid Battery, that is, 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.
Green Lead Cycle
Firstly, primary lead is dispatched to the battery manufacturer and subsequently Lead
Acid Batteries are delivered to the retailer. As we know, the bulk of battery sales are to the automotive sector, but some will be sold for other uses.
Used batteries are usually returned to the retailer for either a refund or a purchase discount and in turn, the retailer will send the ULAB to a collection center for sorting and packaging. Some consumers will also send their ULAB directly to a collection center.
The collection center ships ULAB in bulk to a secondary smelter for recycling and the refined ingots will be sold to the battery manufacturer for the cycle to begin again.
In those instances where there are unregulated smelters or “informal” battery reconditioners operating, there is the distinct possibility that by offering a premium for a
ULAB above that offered under a deposit/refund scheme, that ULAB will find there way into the “informal in the informal sector, where possible, the ULAB will be reconditioned and returned to customers looking for a cheap battery.
Used battery plates and those ULAB deemed beyond repair will be recycled without much recourse to environmental and health controls. In many cases, the lead bullion produced is often marketed to battery manufacturers for use as terminal posts.
It is envisaged that under a Green Lead license, battery manufacturers will only be able to purchase lead ingots from a primary or secondary Green Lead supplier and an outlet for the informal sector will be eliminated .

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
It is anticipated that in this way those working in the informal sector will either get out of the ULAB business or become legitimate collectors of ULAB.
So a 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.

The demand for lead is increasing worldwide
Communities need to be educated about exposure and health effects of Lead
Communities are still exposed to lead from present and past mining and smelting activities worldwide (esp. in developing countries.
Multinational companies appear to be taking some positive steps but more needs to be done to prevent continuous exposure
Stakeholders need to unite and collaborate systemically to reduce emissions, remediate soil contamination, and operate a sustainable monitoring system.
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.
Concerted efforts on a worldwide basis can overcome this menace.
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.

1.
Pollution Prevention and Abatement Handbook: Lead and Zinc Smelting
WORLD BANK GROUP, Effective July 1998
2.
Smith MA. Lead in history. In: Lansdown R, Yule W, eds. Thelead 7. Winder C.
The developmental neurotoxicity of lead. Lancaster, debate: the environmental toxicology and childhealth. London, England, MTP Press, 1984. Croom Helm,
1984: 7–24. 8.
3.
Inorganic lead. Geneva, World Health Organization, 1995
The Centers for Disease Control and Prevention. Atlanta, GA,
(Environmental Health Criteria, No. 165).
4.
Development of an integrated Intervention plan in La Oroya, Peru
http://www.cdc.gov/nceh/ehs/Docs/la_oroya_report.pdf
5.
Lead: Statistics and Information
http://minerals.usgs.gov/minerals/pubs/commodity/lead/
6.
Lead Production and its uses:
http://www.globalleadnet.org/pdf/5.pdf
7.
US Geological Survey
http://minerals.usgs.gov/ds/2005/140/lead.pdf
8.
Base Metal smelting and Refinery: World bank
Environmental Health and Safety Guidelines: April 2007
9.
International Lead Management Center
http://www.ilmc.org/
10.
The Green Lead Initiative - http://www.greenlead.com
11. Chapter 6.7 Lead Air Quality Guidelines - Second Edition
WHO Regional Office for Europe, Copenhagen, Denmark, 2001 13
13.
Health Impacts of Lead Poisoning
E:\who\Health Impacts of Lead Poisoning.htm
14.
Lead Development Association International
http://www.Idaint.org/default.htm
15.
International Lead Zinc Research Organization
http://www.ilzro.org
16.
World Health Organization - www.who.int
17.
The world bank - www.worldbank.org