PORTLAND, Maine (AP) – Officials are warning that ground-level ozone concentrations along the Maine coast will soon reach dangerous levels, which will make for an unhealthy combination with continued high heat, humidity and air quality.

Maine’s Department of Environmental Protections says ground-level ozone concentrations will reach unhealthy levels along the coast Wednesday. Elevated ozone can lead to reduced lung function and irritation for children and healthy adults who exert themselves.

Ozone levels began building in the New York City and Long Island Sound area. The department expects winds will bring those ozone levels to Maine.

Particle pollution levels are expected to be moderate statewide. The National Weather Service has also issued heat advisories.

The state advises against strenuous outdoor activity Wednesday afternoon.

Maine had six days in which ozone exceeded healthy levels in 2017.