A systematic review and meta-analysis of air pollution and increased risk of frailty

Background Environmental air pollution is increasingly recognised as a potential contributor to frailty. This systematic review and meta-analysis aimed to synthesise existing evidence on the associations between environmental air pollution and frailty in middle-aged and older adults, providing insights into the impact of air pollution on public health. Methods The systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement 2020. Four electronic databases were searched without restrictions on language, publication status, or year of publication. Results Of the 145 publications identified through the systematic search, 18 were included. Meta-analyses indicated a 19% increased risk of frailty due to air pollution (fine particulate matter ≤2.5 microns) [n = 9 studies; pooled odds ratio (OR) 1.19; 95% confidence interval (CI) 1.10–1.27], a 28% increase with exposure to household solid fuels (n = 4 studies; OR 1.28; 95% CI 1.16–1.40) and a 59% increase due to exposure to secondhand smoke (n = 3 studies; OR 1.59; 95% CI 0.46–2.72). Except for the meta-analysis on air pollution, no heterogeneity or risk of publication bias was observed amongst the included studies. The Joanna Briggs Institute checklist confirmed high methodological quality across all included studies. Conclusions Environmental exposures, including air pollution, the use of unclean household fuels and exposure to secondhand smoke, significantly increase the risk of frailty. These findings underscore the urgent need to raise awareness and establish effective public health strategies to reduce these environmental risks and associated frailty, particularly in light of population ageing.