The worst air quality in the United States can be found within about 5 football fields of any highway — where 1 in 10 Americans live. Millions of Americans breathe this air every day. And as a result, they suffer from an increased risk of cardiac disease, according to a new study from researchers at Tufts University and Boston University.
The study, slated for publication in the journal Environment International, looked at “ultrafine” pollutants from car exhaust rather than the larger pollutants that are traditionally the focus of air quality research. Researchers found that high concentrations of ultrafine particles — 500 times smaller in diameter than the width of a human hair — are just as toxic as larger particles. While larger particles settle in the lungs, these particles penetrate into the bloodstream, causing inflammation and elevated cholesterol levels. Chronic exposure can cause dangerous plaque buildup in the arteries and eventually lead to heart attack or stroke.
Researchers controlled for age, gender, body fat, and health indicators like whether someone smoked — meaning that they were able to isolate the increased cardiac risk as being connected to people’s proximity to highways.
Local advocates in Boston’s Chinatown, one of the locations where researchers gathered data, are using the findings to call attention to the low-income and minority communities that tend to live near highways.
“In the 1950s they built a highway through Boston’s Chinatown, a community of color,” Mark Liu of the Chinese Progressive Association in Boston, told ThinkProgress. The adverse health consequences continue to this day, he says. “Going forward, we need to make sure parks and building designs promote safety for our community.”
Doug Brugge, one of the researchers and a professor of public health at Tufts University School of Medicine, has emphasized the unique danger of super-tiny airborne toxins for years.
“Most of the mortality, most of the economic impact [of these particulates] are coming from cardiovascular disease,” he told Tufts Medicine in 2012. “It’s not primarily asthma or lung cancer.”
“The Environmental Protection Agency estimates that they cause 80,000 or 100,000 deaths a year in the United States, and maybe four million or more worldwide,” he added.
The new data puts pressure on the EPA to pass national air quality standards regulating ultrafine particles. The EPA regulates air pollutants only as small as 2.5 microns — about one-twentieth the width of a human hair and much bigger than ultrafine particles.
The agency has a strong track record of responding to new research. Each decade since its founding in 1970, the EPA has improved standards, regulating smaller and smaller pollutants.
In the meantime, though, the study’s authors call on lawmakers, developers, and regulators to take action even in the absence of new EPA standards. Filtration systems attached to windows and air conditioning can reduce particle concentration in homes by over 35 percent. Noise barriers and vegetation along roadways can reduce particle concentration in neighboring communities by 50 percent.