Future Directions on Understanding the Link Between Wildfire Particulates and Dementia: Joan A. Casey, PhD & Holly Elser, MD, PhD, MPH

WATCH TIME: 2 minutes

"Reproducibility is the cornerstone of good science, it will be important to see similar research conducted in other study populations and geographic contexts to see how consistent the finding of an association between wildfire, PM 2.5 exposure, and dementia is [among patients]."

Prior research has shown an association between long-term exposure to ambient air pollution, such as fine particulate matter less than 2.5μm in diameter (PM2.5), and incident dementia. In a new retrospective open cohort study, results suggested that long-term exposure to PM2.5, both wildfire and non-wildfire, may be a critical risk factor for dementia.^1,2 This study was presented at the recently concluded 2024 Alzheimer’s Association International Conference, July 28 to August 1, in Philadelphia, Pennsylvania, by lead author Holly Elser, MD, PhD, MPH, senior author Joan A. Casey, PhD, and colleagues.

Among 1,227,241 participants in the study, approximately half of the patients were women (53%) and were married (54%). Notably, a majority of the patients self-identified as non-Hispanic White (49%) or Hispanic (26%). During the study, the mean wildfire PM2.5 concentration was 0.09 (IQR, 9.6–12.4). After the adjustment for covariates, the odds of dementia diagnosis were 10% higher for every 1 μg/m3 higher 3-year average wildfire PM2.5 concentration (OR, 1.10; 95%CI, 0.96-1.25). Additionally, the odds of dementia diagnosis were 1 higher for every 1 μg/m3 higher 3-year average exposure (OR = 1.01; 95%CI, 1.00-1.01) for non-wildfire PM2.5.

Casey, an assistant professor of environmental and occupational health sciences at the University of Washington, and Elser, a neurology resident at the Hospital of the University of Pennsylvania, recently sat down with NeurologyLive^® in an interview to discuss the potential long-term effects of wildfire particulate exposure on cognitive health, particularly dementia. The duo also talked about how indoor air filtration methods like HEPA filters and box fan filters can help mitigate the risks associated with wildfire particulates. Furthermore, the experts spoke about how there could potentially be similar associations between particulate exposure and neurodegenerative diseases like Parkinson disease or amyotrophic lateral sclerosis observed in future research.

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REFERENCES
1. Elser H, et al. Long-term Wildfire Smoke Exposure and Incident Dementia in a Large California Cohort. Presented at: 2024 Alzheimer’s Association International Conference; July 18 to August 1; Philadelphia, Pennsylvania. Abstract 86179.
2. Exposure to Wildfire Smoke Greatly Raises Risk of Dementia Diagnosis. News Release. Alzheimer’s Association.