Sources of PM2.5- and ozone-related health impacts in Europe and their response to emission changes

The deterioration of air quality is a global concern, contributing to millions of premature deaths annually worldwide. In Europe alone, hundreds of thousands of lives are cut short every year due to the effects of air pollution. This alarming reality underscores the need to comprehensively understand the cause of regional air pollution and find cost-effective solutions to mitigate the consequences of air pollution on public health. We have recently established an improved decision support tool to characterize high-resolution sensitivity of PM_2.5- and ozone-related health impacts to different species emissions in Europe by incorporating the satellite-derived surface PM_2.5 concentration products into the GEOS-Chem adjoint model. In 2015, the total PM_2.5- and ozone-related premature deaths are estimated to be 449,813 (257,846–722,138) and 25,432 (7,356–53,160), respectively. The anthropogenic emissions of nitrogen oxides (NO_x), ammonia, and organic carbon contributed most to the PM_2.5-related health damages, making up 29.6%, 23.2%, and 16.8%, respectively of all domestic anthropogenic contributions. Residential, agricultural, and ground transport emissions are calculated to be the largest sectoral sources of PM_2.5-related health risks, accounting for 23.5%, 23.0%, and 19.4%, respectively, of total anthropogenic contributions within Europe. The ozone-related health impacts are mostly associated with the contributions from NO_x emissions. A 20% decrease in anthropogenic emissions can help to avoid 1576 (467–3,252) premature deaths from respiratory diseases. Within these benefits, contributions from emissions of NO_x, volatile organic compounds (VOCs), and CO help to avoid 1105 (328–2,300), 381 (113–770), and 99 (29–200) premature deaths, respectively. During 2005–2015, emission controls reduced PM_2.5-related health damages in nearly all European countries, resulting in 63,538 (46,092–91,082) fewer PM_2.5-related premature deaths. However, our calculation suggests that efforts to reduce air pollution from key sectors in some countries can be offset by the lack of emissions control in others. The emission changes also lead to general increases in the marginal ozone-related health benefit per unit of NO_x emission reduction. Increasing marginal health benefits imply that more costly regulations of NO_x emissions are economically justified even as total anthropogenic emission are declining. International cooperation will thus be important for effectively tackling air pollution and reducing corresponding detrimental effects on public health in Europe.