Using atmospheric models to estimate global air pollution mortality

Ground-level ozone and fine particulate matter (PM2.5) are associated with premature mortality and can influence air quality on global scales. This work examines the global health impacts of ozone and PM2.5 using concentrations simulated by global chemical transport models (CTMs), which allow full spatial coverage and analysis of hypothetical changes in emissions. Here, previous methods using global models are improved by using cause-specific and country-specific baseline mortality rates, and by using area-weighted average rates where gridcells overlap multiple countries. Using these methods, we estimate 0.7 [plus or minus] 0.3 and 3.7 [plus or minus] 1.0 million global premature deaths annually due to anthropogenic ozone and PM2.5, found as the difference between simulations with and without anthropogenic emissions. PM2.5 mortality estimates are ~50% higher than previous measurement-based estimates based on common assumptions, mainly because rural populations are included, suggesting higher estimates, although the coarsely resolved global atmospheric model may underestimate urban PM2.5 exposures. Estimating the mortality impacts of intercontinental transport of ozone shows that for North America, East Asia, South Asia, and Europe, foreign ozone precursor emission reductions contribute ~30%, 30%, 20%, and >50% of the deaths avoided by reducing emissions in all regions together. For North America and Europe, reducing precursor emissions avoids more deaths outside the source region than within, due mainly to larger foreign populations. Finally, using the MOZART-4 global CTM, we estimate that halving global anthropogenic black carbon (BC) emissions reduces population-weighted average PM2.5 by 542 ng/m3 (1.8%) and avoids 157,000 (95% confidence interval, 120,000-194,000) annual premature deaths globally, with the vast majority occurring within the source region. Over 80% of these deaths occur in Asia, with 50% greater mortality impacts per unit BC emitted for South Asian versus East Asian emissions. Globally, the contribution of residential, industrial, and transportation BC emissions to BC-related mortality is 1.3, 1.2, and 0.6 times each sector's contribution to anthropogenic BC emissions, owing to the degree of co-location with population. Future research should improve upon the many sources of uncertainty, incorporate shifting demographics, and examine the health impacts of realistic emission control technologies, which would affect emissions of multiple species simultaneously

Toward a Resilient Global Society: Air, Sea Level, Earthquakes, and Weather

Society’s progress along the four corners of prepare, absorb, respond and adapt resilience square is uneven, in spite of our understanding of the foundational science and a growing sense that urgent action is needed. The resilience vignettes describe the meaning and impact of current and near‐term change in four major domains: human health impacts from air pollution, coastal inundation from sea‐level rise, damaging earthquakes in populated areas, and impacts from extreme precipitation. Given our understanding of the scientific principles, societal action, from preparation to adaption, will be critical in minimizing the negative impacts of change. The unprecedented rates of change in today’s Earth system argue for urgent action in support of a resilient global society.Key PointsUnprecedented rates of change in the Earth system argue for more urgent action in support of a resilient global societyExperts describe the meaning and impact of current and near‐term change in four major domainsWe take an ensemble approach to highlight the similarities for actionable decision‐makingPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151889/1/eft2547_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151889/2/eft2547.pd

The global burden of transportation tailpipe emissions on air pollution-related mortality in 2010 and 2015

Emissions from the transportation sector are a major contributor to ambient air pollution, the leading environmental health risk factor globally. This study aims to quantify the contribution of tailpipe emissions from global transportation, disaggregated by four sub-sectors, to the global disease burden associated with ambient fine particulate matter (PM2.5) and ground-level ozone in 2010 and 2015. We use the GEOS-Chem global chemical transport model to simulate transportation-attributable PM2.5 and ozone concentrations, combined with epidemiological health impact assessment methods consistent with the Global Burden of Disease 2017 study to estimate the associated burden of disease. We estimate that emissions from the transportation sector were associated with 361 000 (95% CI, 258 000&ndash;462 000) PM2.5 and ozone deaths in 2010 and 385 000 (95% CI, 274 000&ndash;493 000) in 2015. These results translate into 11.7% of total global ambient PM2.5 and ozone deaths in 2010 and 11.4% in 2015. Together, PM2.5 and ozone concentrations from transportation tailpipe emissions resulted in an estimated 7.8 million years of life lost and approximately $1 trillion (2015 US$) in health damages globally in 2015. Among transportation sub-sectors, on-road diesels contributed most to the health burden from transportation tailpipe emissions in nearly all trade blocs, for both PM2.5 and ozone, though other sub-sectors also contributed substantially (particularly on-road non-diesel vehicles for ozone mortality, and shipping and non-road mobile sources for PM2.5 mortality). These results indicate that despite recent adoption of more stringent vehicle emission regulations in many countries, the transportation sector remains a major contributor to the air pollution disease burden globally. Future work may explore the degree to which currently adopted policies, as well as expected growth in the transportation sector in India, Africa, and other rapidly developing locations, will influence future transportation-attributable public health burdens. </div

Updated global estimates of respiratory mortality in adults ≥ 30 years of age attributable to long-term ozone exposure

BACKGROUND: Relative risk estimates for long-term ozone (O3) exposure and respiratory mortality from the American Cancer Society Cancer Prevention Study II (ACS CPS-II) cohort have been used to estimate global O3-attributable mortality in adults. Updated relative risk estimates are now available for the same cohort based on an expanded study population with longer follow-up. OBJECTIVES: We estimated the global burden and spatial distribution of respiratory mortality attributable to long-term O3 exposure in adults ≥30 y of age using updated effect estimates from the ACS CPS-II cohort. METHODS: We used GEOS-Chem simulations (2×2.5º grid resolution) to estimate annual O3 exposures, and estimated total respiratory deaths in 2010 that were attributable to long-term annual O3 exposure based on the updated relative risk estimates and minimum risk thresholds set at the minimum or fifth percentile of O3 exposure in the most recent CPS-II analysis. These estimates were compared with attributable mortality based on the earlier CPS-II analysis, using 6-mo average exposures and risk thresholds corresponding to the minimum or fifth percentile of O3 exposure in the earlier study population. RESULTS: We estimated 1.04–1.23 million respiratory deaths in adults attributable to O3 exposures using the updated relative risk estimate and exposure parameters, compared with 0.40–0.55 million respiratory deaths attributable to O3 exposures based on the earlier CPS-II risk estimate and parameters. Increases in estimated attributable mortality were larger in northern India, southeast China, and Pakistan than in Europe, eastern United States, and northeast China. CONCLUSIONS: These findings suggest that the potential magnitude of health benefits of air quality policies targeting O3, health co-benefits of climate mitigation policies, and health implications of climate change-driven changes in O3 concentrations, are larger than previously thought

Air pollution-related health and climate benefits of clean cookstove programs in Mozambique

Approximately 95% of households in Mozambique burn solid fuels for cooking, contributing to elevated indoor and outdoor fine particulate matter (PM2.5) concentrations and subsequent health and climate impacts. Little is known about the potential health and climate benefits of various approaches for expanding the use of cleaner stoves and fuels in Mozambique. We use state-of-thescience methods to provide a first-order estimation of potential air pollution-related health and climate benefits of four illustrative scenarios in which traditional cooking fires and stoves are displaced by cleaner and more efficient technologies. For rural areas, we find that a 10% increase in the number of households using forced draft wood-burning stoves could achieve >2.5 times more health benefits from reduced PM2.5 exposure (200 avoided premature deaths and 14 000 avoided disability adjusted life years, DALYs, over a three-year project lifetime) compared to natural draft stoves in the same households, assuming 70% of households use the new technology for both cases. Expanding use of LPG stoves to 10% of households in five major cities is estimated to avoid 160 premature deaths and 11 000 DALYs from reduced PM2.5 exposure for a three-year intervention, assuming 60% of households use the new stove. Advanced charcoal stoves would achieve ∽80% of the PM2.5-related health benefits of LPG stoves. Approximately 2%–5% additional health benefits would result from reduced ambient PM2.5, depending on the scenario. Although climate impacts are uncertain, we estimate that all scenarios would reduce expected climate change-related temperature increases from continued solid fuel use by 4%–6% over the next century. All results are based on an assumed adjustment factor of 0.8 to convert from laboratory-based emission reduction measurements to exposure reductions, which could be optimistic in reality given potential for continued use of the traditional stove. We conclude that cleaner cooking stoves in Mozambique can achieve health and climate benefits, though both are uncertain and local information about baseline and intervention PM2.5 exposure levels are needed

Thank You to Our 2018 Peer Reviewers

Public trust in science, effective science communication, and rapid and constructive response to authors about their submissions are of paramount importance to the scientific enterprise and indeed to society itself. This is really at the heart of peer review—providing thoughtful insights into both the scientific quality and importance of work, and also how it is communicated to other scientists and increasingly to a broader audience. Very few opportunities exist to acknowledge the mostly anonymous process of peer review, especially given the huge increase in review requests and the relatively mechanical nature of online reviewing platforms. We continue to be humbled by the time, effort, and careful insights that our colleagues share with each other through the process of peer review. In 2018, GeoHealth benefited from more than 83 reviews provided by 53 of our peers for papers submitted to the journal. Thank you all for your awesome efforts toward advancing geohealth now and for the future

Impacts of Intercontinental Transport of Anthropogenic Fine Particulate Matter on Human Mortality

Fine particulate matter with diameter of 2.5 microns or less (PM2.5) is associated with premature mortality and can travel long distances, impacting air quality and health on intercontinental scales. We estimate the mortality impacts of 20 % anthropogenic primary PM2.5 and PM2.5 precursor emission reductions in each of four major industrial regions (North America, Europe, East Asia, and South Asia) using an ensemble of global chemical transport model simulations coordinated by the Task Force on Hemispheric Transport of Air Pollution and epidemiologically-derived concentration-response functions. We estimate that while 93-97 % of avoided deaths from reducing emissions in all four regions occur within the source region, 3-7 % (11,500; 95 % confidence interval, 8,800-14,200) occur outside the source region from concentrations transported between continents. Approximately 17 and 13 % of global deaths avoided by reducing North America and Europe emissions occur extraregionally, owing to large downwind populations, compared with 4 and 2 % for South and East Asia. The coarse resolution global models used here may underestimate intraregional health benefits occurring on local scales, affecting these relative contributions of extraregional versus intraregional health benefits. Compared with a previous study of 20 % ozone precursor emission reductions, we find that despite greater transport efficiency for ozone, absolute mortality impacts of intercontinental PM2.5 transport are comparable or greater for neighboring source-receptor pairs, due to the stronger effect of PM2.5 on mortality. However, uncertainties in modeling and concentration-response relationships are large for both estimates

Global Air Quality and Health Co-benefits of Mitigating Near-Term Climate Change through Methane and Black Carbon Emission Controls

Background: Tropospheric ozone and black carbon (BC), a component of fine particulate matter (PM ≤ 2.5 µm in aerodynamic diameter; PM:2.5), are associated with premature mortality and they disrupt global and regional climate. Objectives: We examined the air quality and health benefits of 14 specific emission control measures targeting BC and methane, an ozone precursor, that were selected because of their potential to reduce the rate of climate change over the next 20–40 years.: Methods: We simulated the impacts of mitigation measures on outdoor concentrations of PM2.5 and ozone using two composition-climate models, and calculated associated changes in premature PM2.5- and ozone-related deaths using epidemiologically derived concentration–response functions. Results: We estimated that, for PM:2.5 and ozone, respectively, fully implementing these measures could reduce global population-weighted average surface concentrations by 23–34% and 7–17% and avoid 0.6–4.4 and 0.04–0.52 million annual premature deaths globally in 2030. More than 80% of the health benefits are estimated to occur in Asia. We estimated that BC mitigation measures would achieve approximately 98% of the deaths that would be avoided if all BC and methane mitigation measures were implemented, due to reduced BC and associated reductions of nonmethane ozone precursor and organic carbon emissions as well as stronger mortality relationships for PM2.5 relative to ozone. Although subject to large uncertainty, these estimates and conclusions are not strongly dependent on assumptions for the concentration–response function. Conclusions: In addition to climate benefits, our findings indicate that the methane and BC emission control measures would have substantial co-benefits for air quality and public health worldwide, potentially reversing trends of increasing air pollution concentrations and mortality in Africa and South, West, and Central Asia. These projected benefits are independent of carbon dioxide mitigation measures. Benefits of BC measures are underestimated because we did not account for benefits from reduced indoor exposures and because outdoor exposure estimates were limited by model spatial resolution.

An Estimate of the Global Burden of Anthropogenic Ozone and Fine Particulate Matter on Premature Human Mortality Using Atmospheric Modeling

Ba c k g r o u n d: Ground-level concentrations of ozone (O 3) and fine particulate matter [ ≤ 2.5 µm in aerodynamic diameter (PM 2.5)] have increased since preindustrial times in urban and rural regions and are associated with cardiovascular and respiratory mortality. Objectives: We estimated the global burden of mortality due to O 3 and PM 2.5 from anthropogenic emissions using global atmospheric chemical transport model simulations of preindustrial and present-day (2000) concentrations to derive exposure estimates. Met h o d s: Attributable mortalities were estimated using health impact functions based on longterm relative risk estimates for O 3 and PM 2.5 from the epidemiology literature. Using simulated concentrations rather than previous methods based on measurements allows the inclusion of rural areas where measurements are often unavailable and avoids making assumptions for background air pollution. Res u l t s: Anthropogenic O 3 was associated with an estimated 0.7 ± 0.3 million respiratory mortalities (6.3 ± 3.0 million years of life lost) annually. Anthropogenic PM 2.5 was associated with 3.5 ± 0.9 million cardiopulmonary and 220,000 ± 80,000 lung cancer mortalities (30 ± 7.6 million years of life lost) annually. Mortality estimates were reduced approximately 30 % when we assume