Health burden attributable to ambient PM_2.5 in China

In China, over 1.3 billion people have high health risks associated with exposure to ambient fine particulate matter (PM_2.5) that exceeds the World Health Organization (WHO) Air Quality Guidelines (AQG). The PM_2.5 mass concentrations from 1382 national air quality monitoring stations in 367 cities, between January 2014 and December 2016, were analyzed to estimate the health burden attributable to ambient PM_2.5 across China. The integrated exposure-response model was applied to estimate the relative risks of disease-specific mortality. Disease-specific mortality baselines in province-level administrative units were adjusted by the national mortality baseline to better reveal the spatial inequality of the health burden associated with PM_2.5. Our study suggested that PM_2.5 in 2015 contributed as much as 40.3% to total stroke deaths, 33.1% to acute lower respiratory infection (ALRI, <5yr) deaths, 26.8% to ischemic heart disease (IHD) deaths, 23.9% to lung cancer (LC) deaths, 18.7% to chronic obstructive pulmonary disease (COPD) deaths, 30.2% to total deaths combining IHD, stroke, COPD, and LC, 15.5% to all cause deaths. The population weighted average (PWA) attributable mortality rates (10⁻⁵ y⁻¹) were 112.0 in current year analysis, and 124.3 in 10-year time lag analysis. The Mortality attributable to PM_2.5 in 10-year time lag analysis (1.7 million) was 12% higher than the current year analysis (1.5 million). Our study also estimated site-specific annual PM_2.5 concentrations in scenarios of achieving WHO interim targets (ITs) and AQG. The mortality benefits will be 24.0%, 44.8%, 70.8%, and 85.2% of the total current mortalities (1.5 million) when the PWA PM_2.5 concentrations in China meets the WHO IT-1, IT-2, IT-3, and AQG, respectively. We expect air quality modeling and cost-benefits analysis of emission reduction scenarios and corresponding health benefits in meeting the site-specific annual PM_2.5 concentrations (WHO IT-1, IT-2, IT-3, and AQG) this study raised. - Highlights: • Health burden attributable to PM_2.5 were estimated with 3 years observed data. • Province-level health benefits of meeting WHO interim standards in China were raised. • 10-year time lag (1.7 million) and current mortality burden analysis (1.5 million) was conducted. • Ambient PM_2.5 pollution have been improved significantly from 2014 to 2016. • Great spatial health inequality caused by PM_2.5 should be considered.