Addressing the source contribution of PM_2.5 on mortality: an evaluation study of its impacts on excess mortality in China

We estimated PM_2.5 concentrations using satellite data and population mortality values for cause-specific diseases and employed the integrated exposure–response model to obtain the associations between exposure and response. PM_2.5 source apportionment data were then used to evaluate the excess mortality attributable to PM_2.5 from different emission sources. In 2013, 1.07 million excess deaths were attributed to PM_2.5 exposure in China. The potentially avoidable excess deaths would be 279 000, 459 000, 731 000 and 898 000 if the PM_2.5 concentrations were reduced to meet WHO interim target (IT)-1 (35 μg m⁻³, also the Chinese standard), IT-2 (25 μg m⁻³), IT-3 (15 μg m⁻³) and the air quality guidelines (10 μg m⁻³), respectively, compared with concentrations experienced in 2013. There were 249 000 (95% CI: 115–337), 228 000 (95% CI: 105–309), 203 000 (95% CI: 94–274), 197 000 (95% CI: 91–266), and 193 000 (95% CI: 88–262) excess deaths attributed to PM_2.5 from coal burning, vehicle emissions, industry-related emissions, dust and other sources in 2013, respectively. Coal burning was the main source of atmospheric PM_2.5; it contributed the most to excess mortalities and the health effects were likely to have been conservatively estimated. Considerable health benefits could be achieved if more stringent ambient PM_2.5 standards were achieved in China. (letter)