The Hidden Toll of Airborne Lead: Infant Mortality Impacts of Industrial Lead Pollution

This paper uses U.S. Toxic Release Inventory data on air lead emissions to provide IV estimates of the effects of air lead concentration on infant mortality. The causal effect of lead on infant mortality is identified by annual variation in air fugitive lead emissions interacted with wind speed near reporting plants, which together determine local ambient lead concentration. Unlike stack emissions, which occur routinely and may prompt avoidance behavior, fugitive emissions are intermittent and influenced by both historical and current factors, such as wind speed variation, making them difficult to avoid. The paper has two main findings. First, higher air lead concentration causes higher infant mortality in the first month and in the first year, suggesting that both in utero and environmental exposures matter. Second, higher lead concentration increases deaths from low birthweight, sudden unexplained infant death (SUID), and respiratory and nervous system causes, which is consistent with findings from animal studies, even when accounting for behavioral responses. Back of the envelope calculations indicate that declines in fugitive lead emissions prevented 34-59 infant deaths per year, generating benefits of $380-$670 million annually in 2023 dollars.