The Maine Department of Environmental Protection has issued an air-quality alert for Sunday. The agency says ground-level ozone is climbing in Maine and will likely reach unhealthy levels. The unhealthy levels are expected along the coast from Kittery through Acadia National park. “Moderate levels of ozone for the Downeast Coastal region and the Western Interior and Eastern Interior regions. In addition, Particle pollution levels are expected to be in the low end of the Moderate range on the Air Quality Index for much of the state as well,” the agency stated in a release. At elevated ozone levels, people with respiratory illnesses might experience reduced lung function and irritation. If you or someone you know is vulnerable to this, health experts recommend avoiding strenuous outdoor activity during the afternoon.