The Effect of Leaded Aviation Gasonline on Blood Lead in Children

Lead is a neurotoxin with developmentally harmful effects in children. In the United States, over half of the current flow of lead into the atmosphere is attributable to lead-formulated aviation gasoline (avgas), used in a large fraction of piston-engine aircraft. Deposition of lead from avgas may pose a health risk to children proximate to airport facilities that service lead-emitting aircraft. Extrapolating from epidemiological evidence on the health and human capital costs of lead poisoning, various public interest firms have petitioned the EPA to find endangerment from and regulate lead emitted by piston-engine aircraft. In the absence of sufficient empirical evidence linking avgas to blood lead levels (BLLs) in children, the EPA has ruled against petitions to find endangerment. To address an EPA request for more evidence, we constructed a novel dataset that links time and spatially referenced blood lead data from 1,043,391 children to 448 nearby airports in Michigan, as well as a subset of airports with detailed data on the volume of piston-engine aircraft traffic. Across a series of tests, and adjusting for other known sources of lead exposure, we find that child BLLs: 1) increase dose-responsively in proximity to airports, 2) decline measurably in children residing in neighborhoods proximate to airports in the months after 9-11, and 3) increase dose-responsively in the flow of piston-engine aircraft traffic. To quantify the policy relevance of our results, we provide a conservative estimate of the social damages attributable to avgas consumption.