Systematic review of Chinese studies of short-term exposure to air pollution and daily mortality

Health effects attributable to air pollution exposure in Chinese population have been least understood. The authors conducted a meta-analysis on 33 time-series and case-crossover studies conducted in China to assess mortality effects of short-term exposure to particulate matter with aerodynamic diameters less than 10 and 2.5 mu m (PM10 and PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O-3) and carbon monoxide (CO). Significant associations between air pollution exposure and increased mortality risks were observed in the pooled estimates for all pollutants of interest. In specific, each 10 mu g/m(3) increase in PM2.5 was askwiated with a 0.38% (95% Confidence Interval, CI: 0.31, 0.45) increase in total mortality, a 0.51% (95% CI: 0.30, 0.73) in respiratory mortality, and a 0.44% (95% CI: 033, 0.54) in cardiovascular mortality. When current annual PM2.5 levels in mega-Chinese cities to be reduced to the WHO Air Quality Guideline (AQG) of 10 mu g/m(3), mortality attributable to short-term exposure to PM2.5 could be reduced by 2.7%, 1.7%, 2.3%, and 62% in Beijing, Shanghai, Guangzhou and Xi&#39;an, respectively. The authors recommend future studies on the nature of air pollution concentration and health effect relationships in Chinese population to support setting stringent air quality standards to improve public health.</p