Association between Fine Particulate Matter Exposure and Cerebrospinal Fluid Biomarkers of Alzheimer's Disease among a Cognitively Healthy Population-Based Cohort

Abstract

BACKGROUND: Epidemiological evidence suggests air pollution adversely affects cognition and increases the risk of Alzheimer's disease (AD), but little is known about the biological effects of fine particulate matter (formula presented , particulate matter with aerodynamic diameter formula presented ) on early predictors of future disease risk. OBJECTIVES: We investigated the association between 1-, 3-, and 5-y exposure to ambient and traffic-related formula presented and cerebrospinal fluid (CSF) biomarkers of AD. METHODS: We conducted a cross-sectional analysis using data from 1,113 cognitively healthy adults (45-75 y of age) from the Emory Healthy Brain Study in Georgia in the United States. CSF biomarker concentrations of formula presented , tTau, and pTau, were collected at enrollment (2016-2020) and analyzed with the Roche Elecsys system. Annual ambient and traffic-related residential formula presented concentrations were estimated at a formula presented resolution, respectively, and computed for each participant's geocoded address, using three exposure time periods based on specimen collection date. Associations between formula presented and CSF biomarker concentrations, considering continuous and dichotomous (dichotomized at clinical cutoffs) outcomes, were estimated with multiple linear/logistic regression, respectively, controlling for potential confounders (age, gender, race, ethnicity, body mass index, and neighborhood socioeconomic status). RESULTS: Interquartile range (IQR; formula presented ) increases in 1-y [formula presented ; 95% confidence interval (CI): formula presented ] and 3-y (formula presented ; 95% CI: formula presented ) ambient formula presented exposures were negatively associated with formula presented CSF concentrations. Associations between ambient formula presented were similar for 5-y estimates (formula presented ; 95% CI: formula presented , 0.005). Dichotomized CSF variables revealed similar associations between ambient formula presented . Associations with traffic-related formula presented were similar but not significant. Associations between formula presented exposures and tTau, pTau formula presented , or formula presented levels were mainly null. CONCLUSION: In our study, consistent trends were found between 1-y formula presented exposure and decreased CSF formula presented , which suggests an accumulation of amyloid plaques in the brain and an increased risk of developing AD. https://doi.org/10.1289/EHP13503.