Coarse Particulate Air Pollution and Daily Mortality: A Global Study in 205 Cities

Rationale: The associations between ambient coarse particulate matter (PM2.5-10) and daily mortality are not fully understood on a global scale. Objectives: To evaluate the short-term associations between PM2.5-10 and total, cardiovascular, and respiratory mortality across multiple countries/regions worldwide. Methods: We collected daily mortality (total, cardiovascular, and respiratory) and air pollution data from 205 cities in 20 countries/regions. Concentrations of PM2.5-10 were computed as the difference between inhalable and fine PM. A two-stage time-series analytic approach was applied, with overdispersed generalized linear models and multilevel meta-analysis. We fitted two-pollutant models to test the independent effect of PM2.5-10 from copollutants (fine PM, nitrogen dioxide, sulfur dioxide, ozone, and carbon monoxide). Exposure-response relationship curves were pooled, and regional analyses were conducted. Measurements and Main Results: A 10 μg/m3 increase in PM2.5-10 concentration on lag 0-1 day was associated with increments of 0.51% (95% confidence interval [CI], 0.18%-0.84%), 0.43% (95% CI, 0.15%-0.71%), and 0.41% (95% CI, 0.06%-0.77%) in total, cardiovascular, and respiratory mortality, respectively. The associations varied by country and region. These associations were robust to adjustment by all copollutants in two-pollutant models, especially for PM2.5. The exposure-response curves for total, cardiovascular, and respiratory mortality were positive, with steeper slopes at lower exposure ranges and without discernible thresholds. Conclusions: This study provides novel global evidence on the robust and independent associations between short-term exposure to ambient PM2.5-10 and total, cardiovascular, and respiratory mortality, suggesting the need to establish a unique guideline or regulatory limit for daily concentrations of PM2.5-10.
Supported by the National Natural Science Foundation of China (92043301, 82030103 [H.K. and C.L.] and 92143301 [R.C.]); the Ministry of Science and Technology, Taiwan (MOST 110–2314-B-002–083 [Y.-L.L.G.]); the Medical Research Council-UK (MR/R013349/1 [A.G.]); Fundação para a Ciência e a Tecnologia through the grant SFRH/BPD/115112/2016 (J.M.); the Australian Research Council (DP210102076 [Y.G.]); the European Union’s Horizon 2020 Project Exhaustion (820655 [A.G., S.R., A.D.-L.P., and A.S.]); the Natural Environment Research Council UK (NE/R009384/1 [A.G.]); the Australian National Health and Medical Research Council (APP2000581, APP1163693, and APP2008813 [Y.G.]); and an Emerging Leader Fellowship of the Australian National Health and Medical Research Council (APP2009866 [S.L.]).