Click to explore pollution levels by county Click to explore pollution levels by county

As we live and breathe, tiny airborne particulates work their way into our lungs and bloodstream and wreak havoc on public health. HealthGrove wanted to compare the air across the Lower 48, so it averaged the daily levels of fine particulate matter from 2003 to 2011 and put them on the map. Sorry, residents of Indiana, Ohio, Kentucky, Tennessee, Alabama, West Virginia, Washington, D.C., Maryland, Illinois, and Pennsylvania; those states round out the top 10 worst offenders.

Now, take a deep breath and take into consideration that all of the states’ PM 2.5 levels adhere to the EPA’s short-term limit of 35 micrograms per cubic meter of air and long-term standard of 15 micrograms. (Delhi, the most polluted city on earth, averages 153 micrograms per cubic meter.) So that’s somewhat reassuring, but there’s still room for improvement. A 2013 study published in The Lancet, for instance, found that for every 5 micrograms per cubic meter increase of PM 2.5 particles, the risk of developing lung cancer jumped by 18 percent.

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