BACKGROUND

Particulate matter consisting of fine particles measuring 2.5 microns or less in diameter (PM), a component of air pollution, has been linked to adverse health outcomes. The objective of this study was to assess the association between ambient PM exposure and survival in children with cancer in the United States.

METHODS

Individuals aged birth to 19 years who were diagnosed with cancer between January 1, 2004, and December 31, 2019, were selected from the National Cancer Database. The association between the annual PM level at the patient's zip code of residence at the time of diagnosis and overall survival was evaluated using time-varying Cox proportional hazards models (crude and adjusted for diagnosis year and age). To address concerns that exposure to air pollution is correlated with other social determinants of health, the authors tested the association between PM levels and survival among sociodemographic subgroups.

RESULTS

Of the 172,550 patients included, 27,456 (15.9%) resided in areas with annual PM concentrations above the US Environmental Protection Agency (EPA) annual PM standard of 12 μg/m. Residing in these high-pollution areas was associated with worse overall survival (adjusted hazard ratio [aHR], 1.06; 95% confidence interval [CI], 1.012-1.10). Similarly, when PM was evaluated as a linear measure, each unit increase in PM exposure was associated with worse survival (aHR, 1.011; CI, 1.005-1.017). Exposure to PM at levels above the EPA standards was also significantly associated with worse overall survival among sociodemographic subgroups.

CONCLUSIONS

Exposure to PM was significantly associated with worse overall survival among children with cancer, even at levels below EPA air quality standards. These results underscore the importance of setting appropriate air quality standards to protect the health of this sensitive population.

PLAIN LANGUAGE SUMMARY

The authors investigated how living in areas with high air pollution (defined as particulate matter consisting of fine particles measuring 2.5 microns or less in diameter; PM) affects the overall survival of children with cancer in the United States. The results indicated that children living in areas with higher PM levels, and even at levels below prior and current US Environmental Protection Agency standards, had lower survival rates than children living in areas with lower levels of PM. This finding emphasizes the need for stricter air quality standards to better protect children, particularly those with serious health conditions like childhood cancer.