Potential reductions in premature mortality attributable to PM2.5 by reducing indoor pollution: a model analysis for Beijing-Tianjin-Hebei of China

摘要

China has one of the highest PM2.5 (particulate matter with an aerodynamic diameter smaller than 2.5 u.m) pollution levels in the world. It might still be long before air quality reaches the National Class II standard 35 ug/m3. We combined outdoor PM2.5 migration model and the Global Burden of Disease 2016 methodology to estimate potential reductions in premature mortality attributable to PM2.5 by reducing indoor PM2.5 to National Class I standard 15 u.g/m3, and compared with reducing outdoor PM2.5 to Government 2020 Interim target of 64 |ig/m3 or National Class II standard 35 ug/m3. Causes of deaths included ischemic heart disease (IHD), stroke, chronic obstructive pulmonary disease (COPD), and lung cancer (LC) for adults; and acute lower respiratory illness (ALRI) for children. A total of 74,000 (95% uncertainty interval: 43,000-111,000) premature deaths were attributable to PM2.5 exposure in 2013. Thirty percent, or 22,000 (17,000-32,000) deaths, would have been averted if indoor PM2.5 had reached the National Class I standard. The benefit is greater than that from reaching the Government 2020 Interim target for outdoor PM2.5 [22%, or 16,000 (12,000-23,000), deaths], although still smaller than that from reaching the National Class II standard [42%, or 31,000 (24,000-45,000), deaths]. A larger relative reduction in deaths was seen in regions with higher PM2.5 levels, e.g., in the southern part of the region, and among children and older people. Reaching the National Class I level of indoor PM2.5 at current outdoor pollution levels could bring considerable health benefits, which are comparable to those from reaching the Government 2020 Interim target for outdoor PM2.5. A strategy that involves both indoor and outdoor cleaning is needed to balance the immediate reduction in PM2.5 exposure and the eventual clean-up of air pollution.