Air Pollution Exposure and Cognitive Function in Taiwanese Older Adults: A Repeated Measurement Study.

Studies related to air pollution exposure and neurocognitive disorders, specifically cognitive impairment, among older adults are limited. We investigated the association between short-term and long-term exposure to ambient air pollution (i.e., particulate matter with an aerodynamic diameter of <10 μm and ozone) and the effects of their interaction on cognitive function in a community-dwelling, free-living elderly population. Study participants were in a multiple-wave representative sample, namely the Taiwan Longitudinal Study on Aging (n = 2241). In four surveys between 1996 and 2007, their cognitive function was assessed using the Short Portable Mental Status Questionnaire (SPMSQ). We estimated air pollution from 1993 to 2007, including daily concentrations of PM ₁₀ and O ₃ from air quality monitoring stations, based on the administrative zone of each participant's residence. Generalized linear mixed models were used to examine these associations after adjusting for covariates. We found that long-term exposure to PM ₁₀ and O ₃ was significantly associated with cognitive impairment (OR = 1.094, 95% CI: 1.020, 1.174 for PM ₁₀ ; OR = 1.878, 95% CI: 1.363, 2.560 for O ₃ ). The joint effect of exposure to PM ₁₀ and O ₃ was associated with cognitive impairment ( p < 0.001). Co-exposure to ambient PM ₁₀ and O ₃ may deteriorate cognitive function in older adults.