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 Air Current Former + _ 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 (g/dL) 150 Children Encephalopathy Nephropathy Death Encephalopathy Nephropathy Frank Anemia Colic 100 Frank Anemia Male Reproductive Effects 50 Hemoglobin Synthesis Vitamin D Metabolism Hemoglobin Synthesis and Female Reproductive Effects 40 30 Nerve Conduction Velocity Elevated Blood Pressure 20 Nerve Conduction Velocity Erythrocyte Protoporphyrin Vitamin D Metabolism(?) Developmental Toxicity IQ, Hearing, Growth 10 Transplacental Transfer Note: = increased function and Adults = decreased function. Source: ATSDR, 1992 Erythrocyte Protoporphyrin (men) Erythrocyte Protoporphyrin (women) 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 analytical 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 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. 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 Sulfur dioxide 400 Arsenic 0.1 Cadmium 0.05 Copper 0.5 Lead Mercury Zinc Particulates 0.5 0.05 1.0 20 Parameter Maximum value pH 6–9 TSS 20 Arsenic 0.1 Cadmium 0.1 Copper 0.5 Iron 3.5 Lead 0.1 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, costeffective 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.