The Environmental Protection Agency’s assessments show that breathing ground-level ozone at levels of just above 0.070 parts per million can cause a range of harmful health effects, including asthma and emphysema.

The effects add up: Air pollution kills tens of thousands of Americans every year and costs the economy over $4 billion.

The damage, however, is not evenly spread. Your exposure to ground-level ozone depends, in no small part, on where you live, and where you live often depends on your economic status. So according to the EPA’s own data — who exactly is America dumping its air pollution burden on?

This map of national ground ozone levels shows a large amount of variation across the country, ranging from safe to hazardous levels. Click on any of the dots signifying monitoring locations to view ozone levels and the demographics of local residents.