First the good news: the amount of lead in America's air has dropped 93 percent since 1980, when the U.S. phased lead out of consumer automobile gasoline. Now the bad: The EPA this week identified 21 areas in 11 states that have levels of lead pollution above agency standards.
Those include Chicago's Pilsen neighborhood, Southern Los Angeles County, and Tampa, Florida. A full list of "non-attainment" areas is available here (pdf).
The 11 states have until June, 2013, to submit cleanup plans, which may include stricter controls on industry, and the areas must be brought into compliance by Dec. 31, 2016.
Lead continues to enter the atmosphere from stationary sources including smelters, power plants, and iron and steel foundries. And there is still lead in the fuel burned by piston-engine aircraft.
In Pilsen, a neighborhood on Chicago's near south side, the EPA monitors air at an elementary school near two stationary sources: the Fisk Power Generating Station, a coal-burning power plant that dates from 1903, and H. Kramer and Co., a brass and copper ingot foundry that has operated since 1888. Although both are cited in EPA reports as sources of lead, EPA points the finger at Kramer:
There are two facilities in the State recommended nonattainment area that emit at, or above, 0.1 tpy of lead. Kramer is one of these facilities, as is the Fisk Electric Generating Station. Analysis performed by IEPA indicates that the Kramer facility is primarily responsible for the elevated levels of lead in the State recommended nonattainment area.
The EPA also identifies steel foundries in northwest Indiana as sources of lead pollution in Chicago.
Smelters and battery plants produce most of the lead air pollution in Southern Los Angeles County, according to EPA, which has also fingered two lead smelters in Tampa.
In addition to exposure to lead in air, people ingest lead in drinking water and contaminated food, as well as incidental ingestion of lead-contaminated soil and dust. Lead-based paint remains a major exposure source in older homes and backyard gardens.
Once taken into the body, lead distributes throughout the body in the blood and is accumulated in the bones. Depending on the level of exposure, lead can adversely affect the nervous system, kidney function, immune system, reproductive and developmental systems and the cardiovascular system. Lead exposure also affects the oxygen carrying capacity of the blood. The lead effects most commonly encountered in current populations are neurological effects in children and cardiovascular effects (e.g., high blood pressure and heart disease) in adults. Infants and young children are especially sensitive to even low levels of lead, which may contribute to behavioral problems, learning deficits and lowered IQ.
In 2008 the U.S. limit for airborne lead pollution became 10 times more stringent, from 1.5 tons per year to .15. The EPA has also designated three areas as unclassifiable because high lead levels are suspected there, but more data is needed. Those areas are Knox County, TN; an area surrounding Hayden, AZ; and Orange County, NY.