Air Pollution and Successful Aging: Recent Evidence and New Perspectives

Worldwide demographic changes occurring in a relatively short period have led to a growing interest in the determinants of aging "successfully" and how to promote a healthier old age. As environmental exposures such as ambient air pollution are believed to play a role in the process of aging, they might represent one of the pathways turning potential successful agers to unsuccessful agers. We aimed to critically review the current epidemiological evidence of the associations between chronic exposure to ambient air pollution and several key determinants of unsuccessful aging and to identify specific populations of unsuccessful agers that are potentially more vulnerable to air pollution's health effects.

Epidemiologic evidence supports the association between air pollution and increased risk for several major chronic diseases, cognitive impairment, frailty, and decreased longevity-all important determinants of unsuccessful aging-as well as evidence for higher vulnerability among frail populations. However, several methodological shortcomings, including possible publication bias, lack of use of an adequate indicator of unsuccessful aging, limitations in exposure assessment, and residual confounding particularly due to socioeconomic status, hinder inference of causal relationship at this stage. Future studies should use constructs such as frailty index to estimate successful aging, as well as integrate time activity patterns into the exposure assessment metric. Additionally, studies in low- and middle-income countries are needed.