(WHTM) — The Pennsylvania Department of Environmental Protection issued a code orange air quality alert on Thursday, July, 13. This affects Cumberland, Dauphin, Lebanon, Lancaster, and York Counties

According to airnow.gov, the air quality alert is not due to wildfire smoke, but it has to do with high ozone concentrations at the surface. Ozone continues to develop near the ground, and most locations will have maximum concentrations reach the moderate range during the day on Thursday.

The CDC says that high concentrations of ozone can harm certain people, especially those who are sensitive to air pollution. This means some residents can experience coughing and pain when taking a deep breath, lung and throat irritation, as well as trouble breathing during outdoor exercise.

A code orange air quality alert means that air pollution concentrations within the region may become unhealthy for sensitive groups. The effects of air pollution can be minimized by avoiding strenuous activity or exercising outdoors.

The Pennsylvania Department of Environmental Protection says that high ozone levels continue to be an issue into Thursday. A chance for afternoon and evening thunderstorms Friday and into the weekend will help bring ozone concentrations down to a healthier level.

The air quality alert is in effect until Friday, July 14 at midnight.