NOAA scientist shows how reducing air pollution has saved lives

Christopher Loughner, an assistant research scientist at the Earth System Science Interdisciplinary Center/Cooperative Institute for Satellite Earth System Studies at the University of Maryland, and scientist at NOAA’s Air Resources Laboratory, is the lead author of “The benefits of lower ozone due to air pollution emission reductions (2002-2011) in the Eastern US during extreme heat," recently published in the Journal of the Air and Waste Management Association. 

Air pollution regulations gave rise to historical air pollution emissions reductions from 2002-2011, resulting in improved air quality, improved human health and lives saved, and economic savings due to reductions in mortality and morbidity. To quantify these improvements, Loughner’s study focused on ozone pollution and health impacts in the eastern U.S. in July 2011. Results suggest that, for this month, emissions reductions: prevented 10-15 ozone exceedance days in the Ohio River Valley and 5-10 in the Mid-Atlantic; resulted in fewer hospital admissions, including 950 fewer for respiratory symptoms, 570 fewer for asthma symptoms and 370 fewer for pneumonia; resulted in 922,020 fewer minor restricted activity days and 430,240 fewer symptoms of asthma exacerbation; and saved between 160 and 800 lives in the Eastern U.S. Overall, these benefits equated to $1.3-$6.5 billion in savings.

The Impact of Reducing Air Pollution

(Click to enlarge) Chart shows the estimated number of avoided deaths (right) and avoided asthma exacerbation events (right) in parts of the Mid-Atlantic, Northeast, Southeast and Midwest in July 2011, thanks to air pollution reductions.

NOAA Research sat down with Loughner to learn more about this study and his broader work on air pollution.

What led you to study air quality?

During my undergraduate work in meteorology, I enjoyed my atmospheric chemistry class more than the typical classes. That led me to graduate school and onward. I was interested in chemistry, how air pollution forms and how changes in the atmosphere move the pollution around, and I was fascinated by how weather impacts air chemistry. 

A lot of my research has been on the interaction between weather and air quality. I’m now focused on dispersion modeling with HYSPLIT. Improving models improves the representation of transport and air chemistry within the atmosphere. 

Did you expect to see such significant results when you began researching the impacts of air pollution emissions controls?

We expected that the level of air quality had improved because we see that with the models. Health impacts are a new avenue of research for me, so I didn’t know how big they could get. We only studied one month, but it was a hot month and you do expect the largest air quality impacts in the summer. It was still surprising to see such significant results because it was one month and not one year. 

The models referred to by Loughner are the Community Multiscale Air Quality model (CMAQ) and the Environmental Benefits Mapping and Analysis Program (BenMAP). CMAQ is an air quality model used for air quality forecasting, as well as for planning purposes to determine how future emissions reductions will impact air quality. BenMAP, on the other hand, is a health impacts and economic model. 

We took ozone concentrations output from CMAQ model simulations and fed them into the BenMAP model, which relies on relationships between air quality and human health impacts developed by epidemiologists (those who study risk factors for diseases and other factors relating to health). We quantified how past emissions reductions saved lives, improved human health, and provided economic benefits. 

What made you choose to focus on July 2011?

It was the hottest month on record in Maryland and we expect similar months in the future. We think it is representative of the future due to climate change. Rising temperatures mean we might not get as large of a decrease in air pollution - the impact of emissions reductions - in the future. When emissions remain the same (at the now reduced levels) but the temperature increases, the air quality worsens. It’s called the “climate penalty factor.”

When you think about the future of air quality modeling, what do you see?

Models will be regularly run at higher resolution to do a better job of capturing local scale circulations, like sea breezes and urban heat islands (areas that are significantly warmer than surrounding rural areas due to human activities).