If you were sitting in a room with 19 other people from around the U.S., researchers say that 15 people in that room would live in an area where air pollution may cause significant health problems.

The American Lung Association reviewed data about air quality from the Environmental Protection Agency and found that up to 60 percent of Americans live in areas where their health could be jeopardized by pollution.

"This should be a wake-up call. We know that air pollution is a major threat to human health," said Stephen J. Nolan, American Lung Association chairman.

Ozone levels are still high in areas near Los Angeles, according to the report, but pollution affects "more than 175 million Americans [who] live in areas with unhealthy smog levels – that’s 80 million more than we identified in last year’s report," according to ALA chief executive officer Charles D. Connor.

People looking at the data can make healthy choices to limit these effects, including supplementing their diet with folic acid.

At Johns Hopkins University, researchers linked folic acid to a reduction in inflammation caused by allergies and asthma, but also to lower wheezing, a common symptom of air pollution.