The D.C. Circuit Court of Appeals has rejected an industry challenge to EPA’s 2008 revision of air quality standards for lead. Coal. of Battery Recyclers Ass’n v. EPA, No. 09-1011 (D.C. Cir. 05/14/10). Petitioners argued that EPA improperly tied its lead national ambient air quality standard (NAAQS) to decreased intelligence quotient (IQ) scores in children, while prior standards were based on blood lead levels. They alleged that such an approach ignored the inherent uncertainty and variability in IQ tests. They also argued that some forms of lead are not readily absorbed by the human body and thus do not pose a health risk.

In revising the lead standards, EPA set primary and secondary standards for lead at 0.15 micrograms per cubic meter, measured on a rolling three-month average that cannot be exceeded over a three-year period. 73 Fed. Reg. 66,964 (11/12/08). The previous standards, in place since 1978, were both 1.5 micrograms per cubic meter.

The court held that EPA supported the inference that lead exposure causes IQ loss and that animal studies show that low levels of lead cause neurobehavioral effects. The court also ruled that EPA adequately responded to petitioner’s arguments about errors in studies the agency relied on and rejected their arguments about the differences in absorption among different types of lead. The court said, “Petitioner’s assertion that the revised lead NAAQS is overprotective because it is more stringent than necessary to protect the entire population of young U.S. children ignores that the Clean Air Act allows protection of sensitive populations."