The EPA has specifically cited airplane fuels among "significant sources of lead" and there is new concern among pilots that engines burning leaded fuel may be targeted by new standards for lead in the air set Wednesday night by the Environmental Protection Agency. The EPA's new limit is the first update since 1978, according to the Associated Press, and sets "a new health standard for lead to slash the amount of the toxic metal in the nation's air by 90 percent." The last update helped phase out leaded gasoline -- the new limit of .15 microgram per cubic meter is ten times lower. Based on air quality data collected from 2004-2006, only 14 counties across the country may be in violation of the new standard when the EPA makes its report in 2011. At this time any future impact of the new standard on general aviation and its use of 100LL fuel is uncertain.
AP reports that the new standard "would require the 16,000 remaining sources of lead, including smelters, metal mines, and waste incinerators, to reduce their emissions." It is state and local governments that will be charge with meeting the new standard. Lead concentrations in the air have declined in recent years, but scientific studies have demonstrated that low level lead exposure is clearly linked to loss of IQ in performance testing.