journal · Public research summary
Air Pollution and Mortality in the Medicare Population
Long-term PM2.5 and ozone exposure were associated with higher all-cause mortality, including in analyses below the standards evaluated at the time.
Educational only. Associations do not establish individual risk or diagnosis. Read the original sources and limitations. Editorial review: 2026-10-06.
Citation
Di et al. · New England Journal of Medicine · 2017 · DOI: 10.1056/NEJMoa1702747
Study design
Cohort study
Population
60,925,443 Medicare beneficiaries aged 65+; follow-up during 2000–2012.
Geography
Continental United States
Finding
Long-term PM2.5 and ozone exposure were associated with higher all-cause mortality, including in analyses below the standards evaluated at the time.
Estimate
Per 10 μg/m³ higher PM2.5: 7.3% higher all-cause mortality hazard (95% CI 7.1–7.5%) in the two-pollutant model.
Measured relationship
Estimated outdoor exposure → all-cause mortality. This paper does not isolate the map's blood-pressure, respiratory or cardiac mechanism.
Limitations
Observational, older US population; ZIP-code exposure is not personal dose. Residual confounding remains possible. Historic standards are not a claim about current safe thresholds.