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Lead
Sources of
Lead
Health Effects
National Ambient Air Quality Standards
Sources of Lead
Lead gasoline additives, nonferrous smelters, and battery plants are the most significant contributors to atmospheric Pb emissions. The highest concentrations of lead are found in the vicinity of nonferrous smelters and other stationary sources of lead emissions.
Health Effects
Exposure to lead mainly occurs through inhalation of air and ingestion of lead in food, paint, water, soil, or dust. Lead accumulates in the body in blood, bone, and soft tissue. Because it is not readily excreted, lead can also affect the kidneys, liver, nervous system, and other organs. Excessive exposure to lead may cause anemia, kidney disease, reproductive disorders, and neurological impairments such as seizures, mental retardation, and/or behavioral disorders. Even at low doses, lead exposure is associated with changes in fundamental enzymatic, energy transfer, and other processes in the body. Fetuses and children are especially susceptible to low doses of lead, often suffering central nervous system damage or slowed growth. Recent studies show that lead may be a factor in high blood pressure and subsequent heart disease in middle-aged white males. Lead may also contribute to osteoporosis in post-menopausal women.
A National Health and Nutrition Examination Survey reported a 78% decrease in blood lead levels from 12.8 to 2.8 µg/dL between 1976 and 1980 and from 1988 to 1991. This dramatic decline can be attributed to the reduction of leaded gasoline and to the removal of lead from soldered cans. Although this study shows great progress, infants and young children are especially susceptible to low doses of Pb, and this age group still shows the highest levels.
National Ambient Air Quality Standards
National primary (health-related) and secondary (welfare-related) Ambient Air Quality Standards for lead are: 1.5 micrograms per cubic meter (µg/m3), maximum arithmetic mean averaged over a calendar quarter. All areas in Region 5 are attaining the NAAQS for lead.