Ambient air pollution exposures and functional decline in a sample of non-demented community-dwelling older adults in Northern Manhattan

Abstract

BACKGROUND AND AIM: A growing body of evidence has linked air pollution exposures to indicators of unhealthy aging. The effects of air pollution on functional performance in older adults remain poorly understood. We investigated cross-sectional and longitudinal associations between air pollution exposures and functional performance. METHODS: From an available pool of 2182 participants enrolled in the Washington Heights-Inwood Aging Project from 1999-2002, 1884 individuals of Hispanic, Non-Hispanic White, or Non-Hispanic Black race-ethnicity who had valid addresses, no diagnosis of probable dementia at study intake, and were not missing data in the outcome measure of interest were selected. Inverse probability of censoring weighted linear mixed-effects models were used to investigate the associations between residential ambient air pollutant concentrations (fine particulate matter [PM2.5] and nitrogen dioxide [NO2]) at baseline and functional performance as measured by an extended Instrumental Activities of Daily living scale (IADL-x), adjusting for potential confounders. RESULTS:Participants were followed for a maximum of six study visits, with a median follow-up time of 4.28 years. Higher concentrations of pollutant exposures were associated with lower IADL-x scores at baseline and steeper rates of decline in IADL-x scores over time. In adjusted models, a one IQR increase in PM2.5 was associated with a 0.275 standard deviation SD (95 % CI: -0.356, -0.194) lower IADL-x score at baseline and an additional 0.031 SD (95% CI: -0.048, -0.013) decline per year of follow-up. A one IQR increase in NO2 was associated with a 0.133 SD (95 % CI: -0.180, -0.086) lower IADL-x score at baseline and an additional 0.035 SD (95% CI: -0.046, -0.024) decline per year of follow-up. CONCLUSIONS:These results contribute to the body of evidence on the deleterious effects of air pollution on healthy aging and point to opportunities for future research on potential pathways linking air pollution exposures to functional decline. KEYWORDS: air pollution, functional performance, aging.