Ground level ozone levels  are expected to reach unhealthy levels in Maine Saturday and into next week, especially along the coast.

The Maine Department of Environmental Protection has issued an air quality alert and advised children and healthy adults who exert themselves and people with respiratory diseases to take steps to avoid breathing problems, such as avoiding strenuous outdoor activities in the afternoon.

The DEP said particle pollution levels will also climb during the next few days.

The DEP issues air quality alerts daily at 3 p.m. on its website at maine.gov/dep.