A meta-analysis of the effect of indoor air pollution on cognitive impairment in middle-aged and older adults

OBJECTIVE: To systematically evaluate the effect of indoor air pollution on the risk of developing cognitive impairment in middle-aged and older adults. METHODS: Computerized searches were conducted in Chinese- and English-language databases, including China National Knowledge Infrastructure, Wanfang, VIP, the Chinese Biomedical Literature Database, PubMed, Web of Science, Embase, and Cochrane Library, for observational studies on indoor air pollution and cognitive function in middle-aged and older adults (≥50 years). The search period was from database inception to March 2026. 2 researchers independently performed study screening, data extraction, and quality assessment, and meta-analysis was conducted using RevMan5.4 and Stata18.0 software. RESULTS: A total of 13 studies were included. The meta-analysis results showed that passive smoking (OR=1.46,95%CI:1.21～1.78,P<0.001) and indoor solid fuel use (OR=1.29,95%CI:1.16～1.45,P<0.001) increased the risk of developing cognitive impairment in middle-aged and older adults. CONCLUSIONS: Both passive smoking and solid fuel use in the home environment significantly increase the risk of developing cognitive impairment in middle-aged and older adults.