Nationwide sociodemographic patterns in airborne exposure to probable carcinogens from industrial sources

Industrial facilities are not located uniformly across the United States (U.S.), and little is known about the quantity of suspected human carcinogens emitted from these sources on a nationwide scale. We evaluated differences in potential exposure to these agents among sociodemographic groups in the U.S. and Puerto Rico.

We used a U.S. regulatory database to identify emissions (pounds) of 32 probable human carcinogens as classified by the International Agency for Research on Cancer. We linked the 2010-2018 average emissions for each agent to 2010 Census tract boundaries and sociodemographic characteristics. We used multinomial, population density-adjusted logistic regression to estimate the odds of a census tract having the highest agent-specific emissions (tertile or quintile) for all sociodemographic predictors (e.g., race and ethnicity, educational attainment, and family poverty).

Industrial facilities emitted an average 32.2 million pounds of probable carcinogens annually across tracts with an estimated 32.8 million residents. The highest proportions of emissions occurred in the South and Midwest and in urban and suburban tracts. The odds of tracts having the greatest burden of dichloromethane, lead, styrene, tetrachloroethylene, acrylamide, aniline, creosote, and epichlorohydrin emissions compared to those with zero emissions were 5 %-43 % higher for Black Americans, whereas White populations were up to 23 % less likely to live in tracts with the highest emissions. Among Hispanics and Latinos, odds were 7 %-14 % higher for dichloromethane, styrene, tetrachloroethylene, and N,N-dimethylformamide. Odds of the highest emissions burden were up to 51 % higher for populations experiencing poverty or with less than high school education, and remained elevated for Black, Hispanic and Latino, and White populations in these strata.

Our novel assessment demonstrates that industrial air emissions of organic and inorganic pollutants that may be carcinogenic to humans disproportionately impact Americans of lower socioeconomic status and who identify as Black, Hispanic, or Latino.