Two environmental organizations have again taken the United States Environmental Protection Agency (“EPA”) to task for failing in its mandatory duty to determine whether greenhouse gases from aircraft engines cause or contribute to air pollution that may reasonably be anticipated to endanger public health or welfare (“Endangerment Finding”), and, if so, to propose and adopt standards to limit those emissions. See Clean Air Act (“CAA”), 42 U.S.C. § 7571(a)(2)(A) (also referred to as “Section 231”).
On April 21, 2010, the EPA announced that it would seek public comment on data available for evaluating emissions and potential exposure to lead in gas used in piston-engine aircraft. As the EPA stated:
Emissions of lead from piston-engine aircraft using leaded avgas comprise approximately half of the national inventory of lead emitted to