Coarse particles and mortality in three Chinese cities: the China Air Pollution and Health Effects Study (CAPES)

Evidence concerning the health risks of coarse particles (PM_10-2.5) is limited. There have been no multi-city epidemiologic studies of PM_10-2.5 in developing Asian countries. We examine the short-term association between PM_10-2.5 and daily mortality in three Chinese cities: Beijing, Shanghai, and Shenyang. PM_10-2.5 concentrations were estimated by subtracting PM_2.5 from PM₁₀ measurements. Data were analyzed using the over-dispersed generalized linear Poisson models. The average daily concentrations of PM_10-2.5 were 101 μg/m³ for Beijing (2007-2008), 50 μg/m³ for Shanghai (2004-2008), and 49 μg/m³ for Shenyang (2006-2008). In the single-pollutant models, the three-city combined analysis showed significant associations between PM_10-2.5 and daily mortality from both total non-accidental causes and from cardiopulmonary diseases. A 10-μg/m³ increase in 1-day lagged PM_10-2.5 was associated with a 0.25% (95% CI: 0.08 to 0.42) increase in total mortality, 0.25% (95% CI: 0.10 to 0.40) increase in cardiovascular mortality, and 0.48% (95% CI: 0.20 to 0.76) increase in respiratory mortality. However, these associations became statistically insignificant after adjustment for PM_2.5. PM_2.5 was significantly associated with mortality both before and after adjustment for PM_10-2.5. In conclusion, there were no statistically significant associations between PM_10-2.5 and daily mortality after adjustment for PM_2.5 in the three Chinese cities.