Ambient coarse particulate pollution and mortality in three Chinese cities: Association and attributable mortality burden

The short-term mortality effects of ambient fine particulate matter air pollution have been widely investigated in China. However, the associations between day-to-day variation in ambient coarse particles pollution (PM_c) and mortality, as well as the corresponding mortality burden, remain understudied. We estimated the short-term PM_c-mortality association in three Chinese cities of the Pearl River Delta (PRD) region during the period of 2013-16. The city-specific association was first estimated using generalized additive models and then combined to obtain the overall effect estimates. We further estimated PM_c related attributable fraction and attributable mortality. Our study found a significant association between PM_c and mortality. Each 10μg/m³ increase of a current day's PM_c was associated with a 1.37% (95% CI: 0.55%, 2.22%) increase in total mortality, a 1.63% increase (95% CI: 0.31%, 2.98%) in cardiovascular mortality, and a 0.97% increase (95% CI: -0.17%, 2.13%) in respiratory mortality in the three cities. We estimated that 0.37% (95% CI: 0.14%, 0.61%) and 2.72% (95% CI: 1.03%, 4.50%) of total mortalities were attributable to PM_c by using China's standards and WHO's air quality guidelines as references-corresponding to 1394 (95% CI: 528, 2291) and 10,305 (95% CI: 3884, 17,000) attributable premature mortalities in the three cities, respectively. This study suggests that ambient coarse particulate pollution might be one important risk factor of total, cardiovascular, and respiratory mortality, as well as account for substantial mortality burdens in the three Chinese cities of the PRD.