Modeled global effects of airborne desert dust on air quality and premature mortality

Fine particulate matter is one of the most important factors contributing to air pollution. Epidemiological studies have related increased levels of atmospheric particulate matter to premature human mortality caused by cardiopulmonary disease and lung cancer. However, a limited number of investigations have focused on the contribution of airborne desert dust particles. Here we assess the effects of dust particles with an aerodynamic diameter smaller than 2.5 μm (DU_2.5) on human mortality for the year 2005. We used the EMAC atmospheric–chemistry general circulation model at high resolution to simulate global atmospheric dust concentrations. We applied a health impact function to estimate premature mortality for the global population of 30 yr and older, using parameters from epidemiological studies. We estimate a global cardiopulmonary mortality of about 402 000 in 2005. The associated years of life lost are about 3.47 million per year. We estimate the global fraction of the cardiopulmonary deaths caused by atmospheric desert dust to be about 1.8%, though in the 20 countries most affected by dust this is much higher, about 15–50%. These countries are primarily found in the so-called "dust belt" from North Africa across the Middle East and South Asia to East Asi

Description and evaluation of GMXe: a new aerosol submodel for global simulations (v1)

We present a new aerosol microphysics and gas aerosol partitioning submodel (Global Modal-aerosol eXtension, GMXe) implemented within the ECHAM/MESSy Atmospheric Chemistry model (EMAC, version 1.8). The submodel is computationally efficient and is suitable for medium to long term simulations with global and regional models. The aerosol size distribution is treated using 7 log-normal modes and has the same microphysical core as the M7 submodel (Vignati et al., 2004). <br><br> The main developments in this work are: (i) the extension of the aerosol emission routines and the M7 microphysics, so that an increased (and variable) number of aerosol species can be treated (new species include sodium and chloride, and potentially magnesium, calcium, and potassium), (ii) the coupling of the aerosol microphysics to a choice of treatments of gas/aerosol partitioning to allow the treatment of semi-volatile aerosol, and, (iii) the implementation and evaluation of the developed submodel within the EMAC model of atmospheric chemistry. <br><br> Simulated concentrations of black carbon, particulate organic matter, dust, sea spray, sulfate and ammonium aerosol are shown to be in good agreement with observations (for all species at least 40% of modeled values are within a factor of 2 of the observations). The distribution of nitrate aerosol is compared to observations in both clean and polluted regions. Concentrations in polluted continental regions are simulated quite well, but there is a general tendency to overestimate nitrate, particularly in coastal regions (geometric mean of modelled values/geometric mean of observed data ≈2). In all regions considered more than 40% of nitrate concentrations are within a factor of two of the observations. Marine nitrate concentrations are well captured with 96% of modeled values within a factor of 2 of the observations

Corrigendum to "Description and evaluation of GMXe: a new aerosol submodel for global simulations (v1)" published in Geosci. Model Dev., 3, 391–412, 2010

No abstract available

The Impact of Fine Particulate Outdoor Air Pollution to Premature Mortality

Epidemiological cohort studies have shown that the long-term exposure to PM2.5 is associated with increased mortality from cardiorespiratory diseases and lung cancer. We use an atmospheric chemistry-general circulation model in combination with population data, country-level health statistics and pollution exposure response functions to investigate the link between premature mortality and several emission source categories, combining all aerosol types that contribute to PM2.5. We estimate the global premature mortality by PM2.5 at 3.15 million/year in 2010. We find that high emissions levels mainly from residential energy use have the largest impact on premature mortality in Eastern and Southeastern Asia (almost 70 % of the global), with China and India being the counties with higher mortality levels attributable. For Europe we estimate 375 thousand premature deaths (about 11 % of the global rate), and 274 thousand deaths for the Eastern Mediterranean region in 2010. In this work we assume that all particles are equally toxic

Model calculated global, regional and megacity premature mortality due to air pollution

Air pollution by fine particulate matter (PM_2.5) and ozone (O₃) has increased strongly with industrialization and urbanization. We estimate the premature mortality rates and the years of human life lost (YLL) caused by anthropogenic PM_2.5 and O₃ in 2005 for epidemiological regions defined by the World Health Organization (WHO). This is based upon high-resolution global model calculations that resolve urban and industrial regions in greater detail compared to previous work. Results indicate that 69% of the global population is exposed to an annual mean anthropogenic PM_2.5 concentration of >10 μg m⁻³ (WHO guideline) and 33% to > 25 μg m⁻³ (EU directive). We applied an epidemiological health impact function and find that especially in large countries with extensive suburban and rural populations, air pollution-induced mortality rates have been underestimated given that previous studies largely focused on the urban environment. We calculate a global respiratory mortality of about 773 thousand/year (YLL ≈ 5.2 million/year), 186 thousand/year by lung cancer (YLL ≈ 1.7 million/year) and 2.0 million/year by cardiovascular disease (YLL ≈ 14.3 million/year). The global mean per capita mortality caused by air pollution is about 0.1% yr⁻¹. The highest premature mortality rates are found in the Southeast Asia and Western Pacific regions (about 25% and 46% of the global rate, respectively) where more than a dozen of the most highly polluted megacities are located

Estimating health and economic benefits of reductions in air pollution from agriculture

Agricultural ammonia emissions strongly contribute to fine particulate air pollution (PM2.5) with significant impacts on human health, contributing to mortality. We used model calculated emission scenarios to examine the health and economic benefits accrued by reducing agricultural emissions. We applied the “value of statistical life” metric to monetize the associated health outcomes. Our analysis indicates that a 50% reduction in agricultural emissions could prevent > 200 thousand deaths per year in the 59 countries included in our study, notably in Europe, Russia, Turkey, the US, Canada and China, accompanied with economic benefits of many billions US$. In the European Union (EU) mortality could be reduced by 18$. A theoretical complete phase-out of agricultural emissions could lead to a reduction in PM2.5 related mortality of > 50% plus associated economic costs in 42 out of the 59 countries studied. Within the EU, 140 thousand deaths could be prevented per year with an associated economic benefit of about 407 billion US$/year. A cost-benefit assessment of ammonia emission abatement options for the EU indicates that the reduction of agricultural emissions generates net financial and social benefits. The monetization of the health benefits of air pollution abatement policies and the costs of implementation can help devise cost-effective air quality management strategies

Exploring the economy-wide effects of agriculture on air quality and health: Evidence from Europe

Agricultural emissions strongly contribute to fine particulate matter pollution (PM2.5) and associated effects on human health. Environmentally-extended input-output models and a regional atmospheric chemistry model (WRF-Chem) were combined to conduct an economy-wide assessment of air pollution and pre-mature mortality in the European Union (EU), associated with a 20% increase in the final demand for the output of the agricultural sector. Model results revealed significant differences in air pollution originating from agricultural growth across the 28 EU countries (EU-28). The highest impact of agricultural growth on PM2.5 concentrations occur over the Northern Balkan countries (Bulgaria and Romania) and northern Italy. However, the highest excess mortality rates in the EU-28 due to changes in emissions and enhanced PM2.5 concentrations are observed in Malta, Greece, Spain and Cyprus. The least affected countries are mostly located in the northern part of Europe, with the exception of the Scandinavian Countries, which have relatively good air quality under current conditions. Our integrated modelling framework results highlight the importance of capturing both the direct and indirect air pollution emissions of economic sectors via upstream supply chains and underscore the non-linear response of surface PM2.5 levels and their health impacts to emission fluxes