Search for: All records

Abstract Ambient fine particulate matter (PM 2.5 ) is the world’s leading environmental health risk factor. Reducing the PM 2.5 disease burden requires specific strategies that target dominant sources across multiple spatial scales. We provide a contemporary and comprehensive evaluation of sector- and fuel-specific contributions to this disease burden across 21 regions, 204 countries, and 200 sub-national areas by integrating 24 global atmospheric chemistry-transport model sensitivity simulations, high-resolution satellite-derived PM 2.5 exposure estimates, and disease-specific concentration response relationships. Globally, 1.05 (95% Confidence Interval: 0.74–1.36) million deaths were avoidable in 2017 by eliminating fossil-fuel combustion (27.3% of the total PM 2.5 burden), with coal contributing to over half. Other dominant global sources included residential (0.74 [0.52–0.95] million deaths; 19.2%), industrial (0.45 [0.32–0.58] million deaths; 11.7%), and energy (0.39 [0.28–0.51] million deaths; 10.2%) sectors. Our results show that regions with large anthropogenic contributions generally had the highest attributable deaths, suggesting substantial health benefits from replacing traditional energy sources. 

Abstract. Recent studies have shown that surface ozone (O3)concentrations over central eastern China (CEC) have increased significantlyduring the past decade. We quantified the effects of changes inmeteorological conditions and O3 precursor emissions on surface O3levels over CEC between July 2003 and July 2015 using the GEOS-Chem model.The simulated monthly mean maximum daily 8 h average O3 concentration(MDA8 O3) in July increased by approximately 13.6 %, from 65.5±7.9 ppbv (2003) to 74.4±8.7 ppbv (2015), comparable to the observedresults. The change in meteorology led to an increase in MDA8 O3 of5.8±3.9 ppbv over the central part of CEC, in contrast to a decreaseof about -0.8±3.5 ppbv over the eastern part of the region. Incomparison, the MDA8 O3 over the central and eastern parts of CECincreased by 3.5±1.4 and 5.6±1.8 ppbv due to the increasedemissions. The increase in averaged O3 in the CEC region resulting fromthe emission increase (4.0±1.9 ppbv) was higher than that caused bymeteorological changes (3.1±4.9 ppbv) relative to the 2003 standardsimulation, while the regions with larger O3 increases showed a highersensitivity to meteorological conditions than to emission changes.Sensitivity tests indicate that increased levels of anthropogenic non-methanevolatile organic compounds (NMVOCs) dominate the O3 increase over theeastern part of CEC, and anthropogenic nitrogen oxides (NOx) mainly increaseMDA8 O3 over the central and western parts and decrease O3 in afew urban areas in the eastern part. Budget analysis showed that netphotochemical production and meteorological conditions (transport inparticular) are two important factors that influence O3 levels over theCEC. The results of this study suggest a need to further assess theeffectiveness of control strategies for O3 pollution in the context ofregional meteorology and anthropogenic emission changes.