Long-Term Exposure to Wildfire PM2.5 Tied to Higher Odds of Dementia

MONDAY, Nov. 25, 2024 (HealthDay News) — Long-term exposure to wildfire and nonwildfire fine particulate matter (PM_2.5) is associated with increased odds of dementia diagnosis, according to a study published online Nov. 25 in JAMA Neurology.

Holly Elser, M.D., Ph.D., from the University of Pennsylvania in Philadelphia, and colleagues examined the association between long-term wildfire and nonwildfire PM_2.5 exposure and the risk for incident dementia in an open cohort study conducted using January 2008 to December 2019 electronic health record data among members of Kaiser Permanente Southern California (KPSC) aged 60 years or older.

Overall, 1,223,107 KPSC members (53.0 percent female) were eligible for inclusion in the study. Of the participants, 26.0 and 49.0 percent identified as Hispanic and non-Hispanic White, respectively. During follow-up, 6.6 percent of participants received a dementia diagnosis. In adjusted models, the researchers observed an association for a 1-µg/m³ increase in the three-year mean of wildfire PM_2.5 exposure with significantly increased odds of a dementia diagnosis (odds ratio, 1.18). A 1-µg/m³ increase in the three-year mean of nonwildfire PM_2.5 exposure was associated with a smaller, but still statistically significant, increase in the odds of dementia diagnosis (odds ratio, 1.01). For wildfire PM_2.5 exposure, members younger than 75 years upon cohort entry, members from racially minoritized subgroups, and those living in high- versus low-poverty census tracts had stronger associations.

“These results align with prior research consistently demonstrating that individual-level and area-level social determinants compound the risk of adverse health outcomes associated with climate-driven environmental exposures,” the authors write.

Two authors disclosed ties to the pharmaceutical and/or medical device industries.

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