A new study by a team from the University of New Mexico, University of Washington and the University of Minnesota examines the health and economic impacts of PM_2.5 pollution (particulates and precursors) in the United States.

Published in Proceedings of the National Academy of Sciences (PNAS), the study estimates that anthropogenic PM_2.5 was responsible for 107,000 premature deaths in 2011, at a cost to society of $886 billion. Of these deaths, 57% were associated with pollution caused by energy consumption [e.g., transportation (28%) and electricity generation (14%)]; another 15% with pollution caused by agricultural activities.

Total damages and attributable premature mortality associated with anthropogenic emissions in 2011 ($ billions) by sector, pollutant, and emission height. Goodkind et al.

A small fraction of emissions, concentrated in or near densely populated areas, plays an outsized role in damaging human health with the most damaging 10% of total emissions accounting for 40% of total damages, the researchers found.

33% of damages occur within 8 km of emission sources, but 25% occur more than 256 km away, emphasizing the importance of tracking both local and long-range impacts.

PM_2.5 atmospheric particles have a diameter of only 2.5 micrometers or smaller and often carry microscopic solid or liquid drops leftover from when they were formed during complex chemical reactions and can sometimes contain dangerous elements. Their small, light nature allows them to stay in the air longer than heavier particles, increasing the possibility of being inhaled and settling into the lungs or bloodstream.

The impact of particulate matter air pollution is enormous even in countries with relatively good air quality like the US. There is still substantial room for improvement to the public health from reducing emissions, even though we have dramatically improved our air quality over the last 40 years.

Sources in the same urban area, releasing the same quantity of emissions, can have orders of magnitude difference in their impacts on health. Identifying those sources with the largest impacts can help improve our decision making about how to reduce pollution.

—University of New Mexico economics professor Andrew Goodkind

The team developed a model for calculating location-specific damages due to primary PM_2.5 and PM_2.5 precursor emissions. Based on the extensive modeling efforts, the researchers are able to rapidly identify the impact of releasing emissions from any location in the US.

They then applied the tool to the US emissions inventory to understand better the contribution of each economic sector on reduced air quality. Such information will be critical in assisting policymakers who are deciding how and where to prioritize pollution mitigation efforts.

Moving forward, the researchers want to focus more directly on certain sectors of the economy where emission reductions have been limited.

Resources

• Andrew L. Goodkind et al. (2019) “Fine-scale damage estimates of particulate matter air pollution reveal opportunities for location-specific mitigation of emissions” Proceedings of the National Academy of Sciences doi: 10.1073/pnas.1816102116