Key points:
- A nationwide study found that people exposed to higher levels of fine particulate air pollution (PM2.5) during infancy had lower economic earnings in adulthood than those exposed to lower levels of PM2.5. The negative association between PM2.5 and economic mobility was strongest in the South and Midwest.
- The study is the first to investigate PM2.5 and economic mobility using granular, census tract-level data and state-of-the-art methods to adjust for confounding variables.
- According to the researchers, the findings point to the need for more stringent air quality standards to protect not only public health but also economic opportunity, and suggest that measures to reduce PM2.5 exposure would be even more effective if tailored to specific regions.
Boston, MA-Higher exposure to fine particulate air pollution (PM2.5) during infancy was associated with lower economic earnings in adulthood in a new study from Harvard T.H. Chan School of Public Health, Harvard John A. Paulson School of Engineering and Applied Sciences, and European University of Rome. The association was most pronounced in the midwestern and southern U.S.
"This study takes a big step toward filling the knowledge gap on the crucial link between environmental factors and long-term economic outcomes," said corresponding author Francesca Dominici, Clarence James Gamble Professor of Biostatistics, Population, and Data Science at Harvard Chan School and faculty director of the Harvard Data Science Initiative. "The findings suggest that air pollution can have lasting impacts beyond health effects-and that these impacts vary across regions and populations."
The study will be published on September 9 in The Proceedings of the National Academy of Sciences.
The study builds upon previous investigations of the relationship between PM2.5 exposure and economic opportunity by using more granular data as well as state-of-the-art causal inference methods to adjust for socioeconomic and demographic confounders. The researchers analyzed data on PM2.5 exposure and economic earnings from 86% of all U.S. census tracts-small statistical subdivisions of a county- from 1980 to 2010. They focused on people born from 1978-83, looking at their mean earnings in 2014-15 when they were between the ages of 31-37. To measure economic mobility, they used a statistic called absolute upward mobility (AUM), which is defined as the mean income rank in adulthood of children born to families in the 25th percentile of the national income distribution.
The study found that the higher a person's exposure in infancy to PM2.5, the lower their earnings in adulthood. Nationwide, on average, an increase in PM2.5 exposure by one microgram per cubic meter (μg/m3) in 1982 was associated with a 1.146% lower AUM in 2015. The study also found that PM2.5 exposure had an outsize impact on AUM in specific regions of the U.S., particularly in the Midwest and South.
"Our findings underscore the necessity of implementing stringent air quality standards nationally," said co-lead author Luca Merlo, researcher at European University of Rome. "They also suggest the necessity of locally tailored interventions to mitigate air pollution and of integrated policies that address both environmental and economic inequalities."
Sophie-An Kingsbury Lee, a student at Harvard John A. Paulson School of Engineering and Applied Sciences, was a co-lead author.
The study was funded by the National Institutes of Health (grants R01MD012769, R01ES028033, 5R01AG060232, R01ES030616, R01AG066793, 1R01ES029950, RF1AG07437201A1, R01MD016054, R01ES034373, RF1AG080948, RF1AG071024, R01ES34021, 1U24ES035309, P30ES000002) and the Alfred P. Sloan Foundation (grant G-2020-13946).
"Childhood PM2.5 exposure and upward mobility in the United States," Sophie-An Kingsbury Lee, Luca Merlo, Francesca Dominici, The Proceedings of the National Academy of Sciences, September 9, 2024, doi: 10.1073/pnas.2401882121
