Fine Particulate Matter Pollution and Risk of Community-Acquired Sepsis

While air pollution has been associated with health complications, its effect on sepsis risk is unknown. We examined the association between fine particulate matter (PM_2.5) air pollution and risk of sepsis hospitalization. We analyzed data from the 30,239 community-dwelling adults in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort linked with satellite-derived measures of PM_2.5 data. We defined sepsis as a hospital admission for a serious infection with ≥2 systemic inflammatory response (SIRS) criteria. We performed incidence density sampling to match sepsis cases with 4 controls by age (±5 years), sex, and race. For each matched group we calculated mean daily PM_2.5 exposures for short-term (30-day) and long-term (one-year) periods preceding the sepsis event. We used conditional logistic regression to evaluate the association between PM_2.5 exposure and sepsis, adjusting for education, income, region, temperature, urbanicity, tobacco and alcohol use, and medical conditions. We matched 1386 sepsis cases with 5544 non-sepsis controls. Mean 30-day PM_2.5 exposure levels (Cases 12.44 vs. Controls 12.34 µg/m³; p = 0.28) and mean one-year PM_2.5 exposure levels (Cases 12.53 vs. Controls 12.50 µg/m³; p = 0.66) were similar between cases and controls. In adjusted models, there were no associations between 30-day PM_2.5 exposure levels and sepsis (4th vs. 1st quartiles OR: 1.06, 95% CI: 0.85⁻1.32). Similarly, there were no associations between one-year PM_2.5 exposure levels and sepsis risk (4th vs. 1st quartiles OR: 0.96, 95% CI: 0.78⁻1.18). In the REGARDS cohort, PM_2.5 air pollution exposure was not associated with risk of sepsis.