The burden of air pollution on years of life lost in Beijing, China, 2004-08: retrospective regression analysis of daily deaths. BMJ 2013;347:f7139. Published 9 December 2013
“The effects of air pollution on human health have recently attracted increasing concern in China, in part due to the increasing number of days with very high levels of air pollution. In most Chinese cities, concentrations of PM2.5 (particulate matter with aerodynamic diameter <2.5 µm) are still far above the level recommended by the World Health Organization’s guidelines on air quality (interim target 2 level) of 10 μg/m3 (annual average) and 25 μg/m3 (24 h average). For example, in 2004-08, mean daily PM2.5 concentration was 105 μg/m3 in Beijing. Beijing is experiencing increasing population density, car use, and expanded construction. It is surrounded by a heavy industrial region, which provides additional sources of air pollutants carried via air flow. Consequently, the ambient pollutant mixture is complex, with the potential for combined toxic effects from many constituents. Reliable estimation of the burden of air pollution on health is essential to support evidence based government policy in this important public health area. Previous studies have examined the effects of air pollution on daily excess deaths or mortality risks using time series methods. Those studies focused on the number of deaths, but did not account for age at death, apart from broad age stratification. We argue that using the number of years of life lost (YLL) provides a complementary indicator to that of excess deaths, because it takes into account the life expectancy at death.”
