A historical assessment of global health impacts by regionally produced PM2.5 pollution

Abstract:

Exposure to the PM2.5 pollution is the greatest environmental risk factor to human health, causing millions of premature deaths in each year. Although often thought as a local problem, the PM2.5 pollution produced regionally can have a global impact through atmospheric transboundary transport, based on observational evidence and model simulations in recent years. A historical account of global premature deaths caused by regionally produced PM2.5 is crucial to help establish an effective strategy for global pollution mitigation. Here we assess the global premature deaths caused by PM2.5 originating from individual regions with different development levels from 1950 to 2014, and quantify the contributions from three driving factors, including population, PM2.5 concentrations and baseline mortality rates. For this purpose, we integrate an updated global anthropogenic emission inventory (CEDS), a 3-dimensional chemical transport model (GEOS-Chem), an updated exposure-response function (GEMM) and a Structural Decomposition Analysis (SDA). We find that from 1950 to 2014, there are cumulatively 187 [95% CI: 150-225] million premature deaths attributable to anthropogenic emissions, with an average of 2.87 [95% CI: 2.3-3.5] million in each year. The upper middle income group is the dominant pollution source, contributing 83 [95% CI: 66-99] million cumulative premature deaths. From 1950 to 2014, although with negative contributions from baseline mortality rates, global premature deaths have been growing as a result of the changes in population (size and age structure) and PM2.5 concentrations (global mean and spatial distribution). Considering the impacts from population growth and aging in the next decades, globally concerted action to mitigate PM2.5 pollution and improve public health care is necessary to minimize the health risk of PM2.5 pollution.