Lead in the Environment

Environmental Standards. Lead in the environment is regulated in the United States because of its potential occupational impact, as well as concern about the impact lead may have on the cognitive and physical development of young children. Standards have been set for lead in air, water, and other environmental media. 

Preventive Measures. The intake uptake biokinetic model (lUBK) projects the impact of lead in the environment on blood lead. This model assumes conservatively high levels of intake and cannot account for chemical speciation, thus over-predictions of blood lead levels often occur. Nonetheless, because of the allegations of the impact of blood lead and neurobehavioral development, blood lead levels in children are being reduced adrninistratively to below 10 //g/dL. In order to do so, soil leads are being reduced to a level of between 500—1000 ppm where remediation is required. 

Patterson felt he had no choice. He would have to focus on lead in the environment. He would have to demonstrate that the preindustrial world had been virtually free of lead pollution. He would have to challenge the giants of American industry carmakers, petroleum companies, lead producers, and chemical corporations. 

Despite the attacks on Patterson s Archives article, it marked the beginning of a major change in USPHS s attitude toward lead in the environment. In response to the article, the agency sponsored the Symposium on... 

Patterson needed every ounce of cantankerousness that he could muster in order to maintain his battle against lead in the environment. A series of three prestigious scientific reports encapsulate his decades-long campaign. In 1971, the first comprehensive study of lead levels in 30 years was issued by a National Research Council panel for the National Academy of Sciences. The committee, which included six representatives from the lead industry, excluded Patterson entirely because he was considered too extreme and unwilling to compromise. The report concluded that the concentration of lead in urban air was rising slowly. 

The levels of lead may build up in plants and animals from areas where air, water, or soil are contaminated with lead. If animals eat contaminated plants or animals, most of the lead that they eat will pass through their bodies. Chapters 4 and 5 contain more information about what happens to lead in the environment. 

The primary source of lead in the environment has historically been anthropogenic emissions to the atmosphere. In 1984, combustion of leaded gasoline was responsible for approximately 90% of all anthropogenic lead emissions. EPA phased out the use of lead alkyls in gasoline, however, and by 1990, auto emissions accounted for only 33% of the annual lead emissions (EPA 1996h). Use of lead additives in motor fuels was totally banned after December 31, 1995 (EPA 1996f). The ban went into effect on February 2, 1996. Atmospheric deposition is the largest source of lead found in soils. Lead is transferred... 

Reliable monitoring data for the levels of lead in contaminated media at hazardous waste sites are needed so that the information obtained on levels of lead in the environment can be used in combination with the known body burdens of lead to assess the potential risk of adverse health effects in populations living in the vicinity of hazardous waste sites. 

Getz LL, Haney AW, Larimore RW, et al. 1977. Transport and distribution in a watershed ecosystem. In Boggess WR, ed. Lead in the environment Chapter 6. Washington, DC National Science Foundation. Report No. NSF/RA-770214, 105-133. 

NriaguJO. 1978. Lead in soils, sediments and major rock types. In Nriagu JO, ed. The biogeochemistry of lead in the environment. Part A. Ecological cycles. New York, NY Elsevier/North-Holland Biomedical Press, 15-72. 

NSF. 1977. Lead in the environment. (Boggess WR, ed.) Washington, DC National Science Foundation. NSFIRA-770214. 

Modified from Nriagu, J.O. (ed.). 1978a. The Biogeochemistry of Lead in the Environment. Part A. Ecological Cycles. Elsevier/North Holland Biomedical Press, Amsterdam. 422 pp. 

The presence of elements known to have adverse health effects in humans such as lead and arsenic is obviously undesirable in food. Environmental sources are the main contributors to contamination of food with most metals and other elements. Some elements (e.g. arsenic) are present naturally but the major sources of other elements (e.g. lead) in the environment are from pollution from industrial and other human activities. The presence of metals and other elements in food can also be the result of contamination from certain agricultural practices (e.g. cadmium from phosphate fertilisers) or manufacturing processes (e.g. tin in canned foods). 

In addition to manufactured organolead compounds, the possibility exists of biological meth-ylation of lead, such as occurs with mercury (see Section 12.7). However, there is a great deal of uncertainty regarding biological methylation of lead in the environment. 

Royal Commission on Environmental Pollution, Ninth Report Lead in the Environment , HMSO, London, 1983. 

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