EPA Finalizes New NAAQS For Lead At 0.15 ug/m3 (10 Times Lower)

Oct 15: U.S. EPA announced it would "dramatically strengthened the nation's air quality standards for lead," which it said would improve public health protection, especially for children [See WIMS 5/1/08]. The new national ambient air quality standards (NAAQS) will tighten the allowable lead level 10 times to 0.15 micrograms of lead (Pb) per cubic meter of air (ug/m3). EPA Administrator Stephen Johnson said, "America's air is cleaner than a generation ago. With these stronger standards a new generation of Americans are being protected from harmful lead emissions."

The decision marks the first time the lead standards have changed in 30 years. EPA said it strengthened the standards after a thorough review of the science on lead, advice from the Clean Air Scientific Advisory Committee, and consideration of public comments. The previous standards, set in 1978, were 1.5 ug/m3. EPA's action sets two standards: a primary standard at 0.15 ug/m3 to protect health; and a secondary standard at the same level to protect the public welfare, including the environment.

EPA noted that the existing monitoring network for lead is not sufficient to determine whether many areas of the country would meet the revised standards. As a result, EPA is redesigning the nation's lead monitoring network, which is necessary for the Agency to assess compliance with the new standard. No later than October 2011, EPA will designate areas that must take additional steps to reduce lead air emissions. States will have five years to meet the new standards after designations take effect.

EPA also said it is retaining the current indicator of Pb in total suspended particles (Pb-TSP). EPA is revising the averaging time to a rolling 3-month period with a maximum (not-to-be-exceeded) form, evaluated over a 3-year period. EPA is also revising data handling procedures, including allowance for the use of Pb-PM10 data in certain circumstances, and the treatment of exceptional events, and ambient air monitoring and reporting requirements for Pb, including those related to sampling and analysis methods, network design, sampling schedule, and data reporting. Finally, EPA is revising emissions inventory reporting requirements and providing guidance on its approach for implementing the revised primary and secondary standards for Pb.

EPA said that more than 6,000 studies since 1990 have examined the effects of lead on health and the environment. Some studies have linked exposure to low levels of lead with damage to children's development, including IQ loss. Lead can be inhaled or can be ingested after settling out of the air. Ingestion is the main route of human exposure. Once in the body, lead is rapidly absorbed into the bloodstream and can affect many organ systems including children's developing nervous systems.

Lead emissions have dropped nearly 97 percent nationwide since 1980, largely the result of the Agency's phase-out of lead in gasoline. Average levels of lead in the air today are far below the 1978 standards. Lead in the air comes from a variety of sources, including smelters, iron and steel foundries, and general aviation gasoline. More than 1,300 tons of lead are emitted to the air each year, according to EPA's most recent estimates.

Environmental Defense Fund (EDF) issued a release saying, "While EPA’s own analysis justifies an even lower lead standard, this tenfold reduction will go a long way to protecting children most at risk from airborne lead. It’s refreshing to see the agency follow the science and the advice of its experts in making this decision.”

The Natural Resources Defense Council (NRDC) said, "We commend EPA for taking a giant step in the right direction, but they need to greatly expand the lead monitoring network if they hope to enforce this new standard. The EPA has followed the advice of its own advisers and public health advocates to set a more stringent standard for airborne lead." However, NRDC said EPA's "plan for only 236 new or relocated monitors is not adequate to detect problems" and it was "disappointed that EPA will allow averaging of lead exposures over a three-month period."

Access a release from EPA (click here). Access the prepublication copy of the 413-page final rule (click here). Access EPA Lead In Air website for links to extensive information (click here). Access the docket for this rulemaking for complete information (click here). Access a release from EDF (click here). Access a release from NRDC (click here). [*Air, *Toxics]