Historical Trends in PM2.5-Related Premature Mortality during 1990-2010 across the Northern Hemisphere.

Background:Air quality across the northern hemisphere over the past two decades has witnessed dramatic changes, with continuous improvement in developed countries in North America and Europe, but a contrasting sharp deterioration in developing regions of Asia.Objective:This study investigates the historical trend in the long-term exposure to PM2.5 and PM2.5-related premature mortality (PM2.5-mortality) and its response to changes in emission that occurred during 1990–2010 across the northern hemisphere. Implications for future trends in human exposure to air pollution in both developed and developing regions of the world are discussed.Methods:We employed the integrated exposure–response model developed by Health Effects Institute to estimate the PM2.5-mortality. The 1990–2010 annual average PM2.5 concentrations were obtained from the simulations using the WRF-CMAQ model. Emission mitigation efficiencies of sulfur dioxide (SO2), nitrogen oxides (NOx), ammonia (NH3), and primary PM are estimated from the PM...