Air pollution and dementia in older adults in the Ginkgo Evaluation of Memory Study
Erin O. Semmens, Cindy S. Leary, Annette L. Fitzpatrick, Sindana D. Ilango, Christina Park, Claire E. Adam, Steven T. DeKosky, Oscar L. López, Anjum Hajat, Joel D. Kaufman
Abstract
Abstract Introduction Growing evidence implicates air pollution as a risk factor for dementia, but prior work is limited by challenges in diagnostic accuracy and assessing exposures in the decades prior to disease development. We evaluated the impact of long‐term fine particulate matter (PM 2.5 ) exposures on incident dementia (all‐cause, Alzheimer's disease [AD], and vascular dementia [VaD]) in older adults. Methods A panel of neurologists adjudicated dementia cases based on extensive neuropsychological testing and magnetic resonance imaging. We applied validated fine‐scale air pollutant models to reconstructed residential histories to assess exposures. Results An interquartile range increase in 20‐year PM 2.5 was associated with a 20% higher risk of dementia (95% confidence interval [CI]: 5%, 37%) and an increased risk of mixed VaD/AD but not AD alone. Discussion Our findings suggest that air pollutant exposures over decades contribute to dementia and that effects of current exposures may be experienced years into the future.