Fine Particulate Matter and Poor Cognitive Function among Chinese Older Adults: Evidence from a Community-Based, 12-Year Prospective Cohort Study

BACKGROUND: Research on the relationship between long-term exposure to particulate matter with aerodynamic diameter [Formula: see text] ([Formula: see text]) and poor cognitive function is lacking in developing countries, especially in highly polluted areas. OBJECTIVES: We evaluated associations of long-term exposure to [Formula: see text] with poor cognitive function in a diverse, national sample of older adults in China. METHODS: This analysis included data on 13,324 older adults (5,879 who were 65–79 years of age, 3,052 who were 80–89 years of age, 2,634 who were 90–99 years of age, and 1,759 who were [Formula: see text] of age) with normal cognitive function at baseline from March 2002 to September 2014, with 64,648 person-years of follow-up. We used a geographic information system analysis to estimate the annual average satellite-derived [Formula: see text] concentration for the geocoded location of the participants’ baseline residences. Poor cognitive function was defined as a score of less than 18 on the Chinese version of the Mini-Mental State Examination (MMSE). Competing risk models were performed to explore the association of [Formula: see text] with poor cognitive function. RESULTS: Each [Formula: see text] increase in [Formula: see text] was associated with a 5.1% increased risk of poor cognitive function [adjusted hazard ratio (HR): 1.051; 95% confidence interval (CI): 1.023, 1.079]. Compared to the lowest quartile of [Formula: see text] ([Formula: see text]), adjusted [Formula: see text] values were 1.20 (95% CI: 1.09, 1.33), 1.27 (95% CI: 1.15, 1.41), and 1.21 (95% CI: 1.09, 1.34) for the second ([Formula: see text]), third ([Formula: see text]), and fourth ([Formula: see text]) quartiles of [Formula: see text] , respectively (p for trend [Formula: see text]). Subgroup analyses suggested stronger associations between [Formula: see text] and poor cognitive impairment in men than women. The association was positive in the 65- to 79- and [Formula: see text] age group but not significant and positive in the other two age groups with similar results. CONCLUSION: [Formula: see text] was identified as a risk factor for poor cognitive function in Chinese older adults. Improving air quality may reduce the future population burden of poor cognitive function, especially in areas with high air pollution. https://doi.org/10.1289/EHP5304