MORRISTOWN (AP) -- Tennessee environmental officials have issued an air quality alert for much of the eastern Tennessee River Valley and extreme southwestern Tennessee.

The Code Orange Alert is for the metro areas of the Tri-Cities, Knoxville, Chattanooga and Memphis.

It also includes the Great Smoky Mountains National Park.

The Environment and Conservation Department said ground level concentration of ozone could approach unhealthy standards. The alert is more of a concern to people with breathing problems.

Meteorologist David Hotz of the National Weather Service said Wednesday that stagnant air will likely remain in place over Independence Day, with a chance of showers and thunderstorms improving air quality on Saturday.