A Systematic Review and Meta-Analysis on Long-Term Exposure to Particulate Matter and All-Cause and Cause-Specific Mortality in the Asia-Pacific States

Background
Global Burden of Disease (GBD) studies have proposed integrated exposure-response models primarily based on North American and European data, which may not be directly applicable to the Asia-Pacific region. Through a systematic review and meta-analysis, we aimed to explore the association between long-term exposure to ambient particulate matter (PM) and mortality in the Asia-Pacific states.

Methods
We searched 3 databases (PubMed [n = 8,326], Embase [n = 4,709], and Cochrane Library [n = 357]) between 1st January 1990 and 31st July 2023. Our search focused on studies examining the associations between long-term exposure to PM with an aerodynamic diameter < 2.5 μm (PM2.5) and 10 μm (PM10) and all-cause (or non-accidental) and cause-specific mortality, including cardiovascular disease (CVD), ischemic heart disease (IHD), stroke, acute lower respiratory infection, chronic obstructive pulmonary disease, and lung cancer deaths in the Asia-Pacific states. We conducted a meta-analysis to pool the estimates in the studies.

Results
We identified 71 articles investigating the association between long-term exposure to PM and all-cause and cause-specific mortality. For a 10 μg/m3 increase in PM2.5, the pooled relative risk (RR) with 95% confidence intervals (CI) for all-cause mortality was 1.11 (95% CI, 1.05–1.17), 1.13 (95% CI, 1.06–1.21) for CVD, 1.13 (95% CI, 1.02–1.25) for IHD, 1.12 (95% CI, 1.02–1.24) for stroke, and 1.12 (95% CI, 1.08–1.16) for lung cancer. For a 10 μg/m3 increase in PM10, the pooled RR for all-cause mortality was 1.12 (95% CI, 1.00–1.24) and 1.33 (95% CI, 1.28–1.38) for IHD.

Conclusion
Our analysis revealed positive associations between long-term exposure to PM and all-cause and cause-specific mortality for CVD, IHD, stroke, and lung cancer in the Asia-Pacific states.

Trial Registration
PROSPERO Identifier: CRD42023441916