EPA has proposed to revise the nation's air quality standards for lead for the first time in 30 years.

The proposal recommends tightening the primary standard to protect public health by 80 percent to 93 percent. It would revise the existing standard of 1.5 micrograms per cubic meter of air to a level within the range of 0.10 to 0.30 micrograms per cubic meter. The agency is taking comment on alternative levels within a range from less than 0.10 to 0.50 micrograms per cubic meter.

Since 1980, emissions of lead to the air have dropped nearly 98 percent nationwide, largely the result of the agency's phaseout of lead in gasoline. And average levels of lead in the air are far below the level of the 1978 standard. Lead in the air today comes from a variety of sources, including smelters, iron and steel foundries, and general aviation gasoline. About 1,300 tons of lead are emitted to the air each year, according to EPA's most recent estimates.

EPA will accept public comment for 60 days after the proposal is published in the Federal Register. The agency will hold two public hearings on June 12, 2008: one in St. Louis and one in Baltimore. EPA must issue a final decision on the lead standard by September 15, 2008.