New research at the University of New Mexico is looking into how much particulate matter air pollution costs the US every year -- and how best to tackle it.
Fine particulate matter (PM2.5) air pollution caused an estimated 107,000 premature deaths in 2011, the study reports. The authors say these deaths cost society at large around $886 billion, and than 57% of them were at least partially the result of pollution caused by energy consumption (i.e. transportation or electricity generation).
Bad air
"The impact of particulate matter air pollution is enormous even in countries with relatively good air quality like the U.S.," says University of New Mexico economics professor Andrew Goodkind.
"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."
PM2.5 are particles with a diameter of or under 2.5 micrometers. They're exceedingly small, so small, in fact, that we can only see them under an electron microscope. You could string 30 such particles along and they would still be shorter than the diameter of a single one of your strands of hair. Not just invisible to the naked eye, these particles are also quite toxic. They often carry along microscopic amounts of solid or liquid leftovers of the chemical reactions that created the particles themselves -- these residues can be quire hazardous to human health.
What makes PM2.5 really troublesome, however, is that they're so tiny they don't really decant from they air; they just float around for long stretches at a time. Because of this, they have a very high chance, compared to other pollutants, to make their way into your lungs and bloodstream.
However, the effect of PM2.5 on general health depends greatly on where they are emitted or released. So, Goodkind's team set about understanding how geography plays a part in their effect.
The team developed a model for calculating location-specific damages due to primary PM2.5 and PM2.5 precursor emissions. Based on these models, the team can estimate the impact of PM2.5 emissions in any location throughout the US, they say. And that's exactly what they did -- they applied the modeling tool to the U.S. emissions inventory to understand how each economic sector contributes to reduced air quality.
They found that 33% of health damages associated with PM2.5 occur within 8 km of emission sources, but 25% occur more than 150 miles away. These results emphasize the importance of tracking both local and long-range impacts, which is another element of what the paper addresses.
"Sources in the same urban area, releasing the same quantity of emissions, can have orders of magnitude difference in their impacts on health," Goodkind said. "Identifying those sources with the largest impacts can help improve our decision making about how to reduce pollution."
The team hopes policymakers will use their results to decide how and where to prioritize pollution mitigation efforts. They also plan to expand on their research by focusing more directly on certain sectors of the economy where emission reductions have been limited.
"Coal-fired electricity generation has, rightly, received substantial attention, and emissions have dropped substantially, but many people do not realize that agriculture is the source of a significant share of emissions," Goodkind concluded. "We are looking into how and where we grow crops and raise livestock, what inputs are used, and how we can improve the system to continue to produce the food we need but with fewer environmental and health impacts."
The paper "Fine-scale damage estimates of particulate matter air pollution reveal opportunities for location-specific mitigation of emissions" has been published in the journal Proceedings of the National Academy of Sciences (PNAS).
