Higher air lead concentration linked to increased infant mortality

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A new study has found a statistically significant relationship between air lead concentration and infant mortality, highlighting the ongoing risks posed by industrial emissions even in developed countries like the United States. The research, conducted by economists from Carnegie Mellon University, Boston College, and Hunan University, provides the first causal estimates of airborne lead’s impact on infant mortality in settings with modern medical care and at contemporary exposure levels.^1,2

“Although many studies have examined the adverse effects of lead on children’s cognitive and behavioral outcomes, few have analyzed the effect of exposure to lead on infants’ health, so we know little about the extent of harm to infants’ health from airborne lead,” said Karen Clay, professor of economics and public policy at Carnegie Mellon’s Heinz College and the study’s lead author.¹

Research methodology

The study used U.S. Toxic Release Inventory (TRI) data on lead emissions to determine the effect of air lead concentration on infant mortality. The researchers employed an innovative approach by using annual variations in fugitive lead emissions—those that escape from industrial processes into the air—and wind speed near reporting plants to estimate local ambient lead concentration. This method allowed them to isolate the causal effect of lead exposure on infant mortality while controlling for other pollutants.²

Key findings

The findings indicate that higher concentrations of lead in the air led to an increase in infant mortality in both the first month and first year of life, suggesting that both in utero and postnatal exposure play a role. In particular, higher lead levels were linked to increased deaths due to low birthweight, sudden unexplained infant death (SUID), and respiratory and nervous system causes.²

The study’s estimates suggest that declines in fugitive lead emissions alone prevented 34 to 59 infant deaths per year, with economic benefits ranging from $380 million to $670 million annually. Expanding the scope to include all TRI-reported reductions in air lead concentrations, the researchers estimate that approximately 241 infant deaths were prevented per year, amounting to $2.7 billion in economic benefits annually.²

Edson Severnini, associate professor of economics at Boston College and coauthor of the study, emphasized the implications of their findings. “Back-of-the-envelope calculations indicate that declines in fugitive lead emissions prevented 34 to 59 infant deaths per year, generating benefits of $380 million to $670 million annually,” he stated.¹

The research also sheds light on potential mechanisms underlying these effects. Previous studies have linked lead exposure to damage in neurological development, potentially disrupting sleep and arousal mechanisms, which could contribute to conditions such as sudden infant death syndrome (SIDS), a subset of SUID (Lyngbye et al., 1985; Clay et al., 2025). In addition, animal studies have shown that lead exposure weakens the immune system, which may increase vulnerability to respiratory illnesses.²

Call for stricter regulations

Despite significant progress in reducing lead exposure from gasoline and paint, industrial emissions continue to contribute to elevated air lead levels. “In the United States, industrial firms and the aviation industry still emit hundreds of thousands of pounds of lead into the air,” noted Xiao Wang, assistant professor of economics and trade at Hunan University and coauthor of the study. “Our new estimates can inform investments in reducing air lead emissions and soil cleanups.”¹

Conclusion

The findings contribute to a growing body of research on the health impacts of lead exposure and reinforce the need for continued efforts to reduce industrial lead emissions. The study suggests that stricter air quality regulations and targeted remediation efforts could yield significant public health benefits, particularly for vulnerable infant populations.²

References:

1. Carnegie Mellon University. Infant mortality tied to concentration of lead in air. Eurekalert. February 25, 2025. Accessed February 27, 2025. https://www.eurekalert.org/news-releases/1074938

2. Clay KB, Severnini E, Wang, X. The Hidden Toll of Airborne Lead: Infant Mortality Impacts of Industrial Lead Pollution (February 2025). NBER Working Paper No. w33447. https://ssrn.com/abstract=5130539