Air quality research betters public health and policy
June 24, 2014
About half of the U.S. population lives in counties that are failing air quality standards set by the Environmental Protection Agency. And globally, air pollution has been identified as the world’s biggest environmental health risk. It causes 7 million deaths per year, according to a recent World Health Organization report.
“Even though air pollution is getting better, it is still posing major health risks, even within the United States,” says Tracey Holloway, an associate professor of environmental studies at UW-Madison and faculty affiliate of the Nelson Institute Center for Sustainability and the Global Environment.
Holloway studies air quality, not only because of its critical impacts on global health, but because it offers a dynamic perspective of various sustainability factors.
“Because air quality cuts across energy, transportation, land use, weather and climate, it’s a nice lens to see how all the pieces fit together,” she says. “I enjoy that part of the problem solving.”
Air pollutants have concerned scientists and politicians since 1881, when the cities of Chicago and Cincinnati passed the first laws aimed at reducing smoke pollution caused by the proliferation of coal power.
Since then, air quality has generally been improving due to policy decisions and improvements in energy efficiency. Progress largely began with the Clean Air Act of 1970, which gave the federal government power to regulate air pollution from cars and industries.
“In some ways, air quality in the United States is a real success story,” says Holloway. “Since the 1970s, we have made reductions in most pollutants that damage human health, and even over the past five years, we have seen improvements.”
Tracey Holloway
But there’s still a lot of work to do. Moreover, efforts to improve air quality often have unintended consequences. As the United States moves to regulate carbon dioxide along with traditional air pollutants, some control strategies may change. For example, scrubbers – devices placed in the stacks of coal-fired power plants to remove gases or particulates – reduce the emission of sulfur dioxide, a byproduct of burning coal that can cause lung disease and acid rain.
However, Holloway says that these scrubbers require a lot of energy to operate. So a power plant running scrubbers needs to generate more energy, thus emitting more carbon dioxide and contributing to global climate change.
But there are also win-win solutions, Holloway says. Switching from coal to natural gas improves power plant efficiency by moving to a fuel that emits less carbon dioxide and fewer pollutants harmful to humans. The same holds true when conserving energy, or replacing fossil fuels with renewable energy alternatives.
Because of the multiple options for improving air quality, policy makers need to be able to determine where to concentrate limited resources and political capital. Modeling developed by Holloway and other researchers can help set priorities.
“We want to know, from an air quality perspective, where you get the most figurative ‘bang for your buck,’” says Holloway, who also serves as deputy leader of the NASA Air Quality Applied Sciences Team, which works to connect science data and tools with policy needs for air quality control.
“For example, coal and diesel are both relatively dirty fuels,” she continues. “Coal is dirtier, but power plant emissions are often happening far from where people are living, whereas diesel trucks are driving through the cities, so there is direct exposure.”
Holloway’s team is investigating changes in emission levels when power plants and trucks are converted to natural gas, and the resulting impact on air quality. Policy makers can use this information to make the most effective decisions.
When planning a cleaner future, though, Holloway says the biggest challenges are often artifacts of the past.
“There are a lot of different parameters that can be adjusted if we’re thinking about how to build a city that has healthy communities, healthy air and other desirables,” says Holloway.“But sometimes it’s hard to go back in time.”
Cities like Los Angeles were built in the era of the automobile, so they are spread out and residents must do a lot of driving to get anywhere. Salt Lake City was built in a basin, which often traps pollutants. Cities like Madison are hot in the summer, creating issues with ozone, a chemical that results from reactions between automobile or industrial pollutants, such as nitrogen oxides and volatile organic compounds, and sunlight.
Americans have made great strides in improving air
quality, but pollution still poses major health risks.
Holloway says these challenges are difficult but they can be addressed, not only by policy makers but by everyone.
“Individuals play a big role here when thinking about how they use electricity, how they heat and cool their home, how they get around town, and even paying attention to when there are dirty air days and clean air days,” she explains. “If it’s a bad air day in your community, you can take steps like trying to drive less, or avoiding mowing your lawn in the middle of the day, and avoiding using cleaning products with volatile compounds.”
Because of policies such as the Clean Air Act as well as growing awareness, Americans have made great strides in improving air quality. For example, when Holloway first arrived at UW-Madison in 2003, every Wisconsin county along the Lake Michigan coast violated the federal ozone standard. Today, every Wisconsin county but one now complies with that standard, even though it has toughened.
These changes not only improve air quality; they also save money. Studies have shown that for every dollar spent on improving air quality, $2 to $22 is saved on health care. And clean air means more than just savings.
“I would say that, as citizens, we’ve decided that we value clean air. It means that we can walk out of our door and not be coughing, and not have to wear masks,” says Holloway.