Because of the EPA-mandated phase-down in the use of leaded gasoline, lead contamination in air has significantly reduced over the past 20 years. EPA reports that total atmospheric lead emissions dropped 94 percent between 1978 and 1987 because of its phase-down of leaded gasoline, the introduction of unleaded gasoline in new cars, and a decrease in the number of vehicles that burn leaded gasoline.
This reduction of lead in air correlates very well with declines in childhood blood lead levels between 1976 and 1991, as documented by the second and third National Health and Nutrition Examination Surveys (NHANES II and III).
However, leaded gasoline is not the only source of lead contamination in air. Air can also be contaminated by emissions from stationary sources, such as smelters and battery factories, and from the combustion of oil, coal, waste oil, and municipal wastes. Windblown dust is another source of air contamination.
Studies in Ohio (University of Cincinnati and Case-Western Reserve University) have demonstrated that dust from the demolition of old buildings is a major contributor to neighborhood dust and soil lead levels. Lead emissions from industrial and other stationary sources have declined because of compliance with state plans and regulations aimed at achieving national air quality standards.
Lead contamination in air remains a significant problem at many worksites, especially where renovation, lead abatement, and recoating of bridges or other steel structures are conducted. The National Institute of Occupational Safety and Health (NIOSH) reports that workers are frequently poisoned by lead while working on bridges (a high percentage of bridges are painted with lead-based paint).
Operations such as abrasive blasting, sanding, burning, or welding on steel structures coated with lead-containing paints may produce very high concentrations of lead dust and fumes, If there activities are not properly contained, the dusts and fumes generated can drift and contaminate waterways and adjacent neighborhoods.
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