The American Lung Association has released new data about air quality throughout the country.
Click here to explore the association's air quality data for New Hampshire.
No county in New Hampshire reported days with such unhealthy air quality that the general population couldn’t be outside.
But five counties — Rockingham, Hillsborough, Grafton, Cheshire and Belknap — reported at least one day where air quality was unhealthy for those with asthma, heart disease and lung disease.
New Hampshire's most populous counties — Hillsborough, Merrimack and Rockingham — have the most people at high risk for pediatric and adult asthma, COPD and lung cancer, according to the report.
Still, the American Lung Association says air quality in those counties is decent.
Hillsborough and Rockingham got a "B" grade for particle pollution. Merrimack County did not report that data.
Meanwhile, Hillsborough received an "A" grade on high ozone days, while Merrimack got a "B" and Rockingham a "C."
The American Lung Association says particle pollution can cause early death, heart attacks and strokes, and ozone can irritate the lungs much like a sunburn on skin.