Air-quality alert in effect Thursday

An air-quality alert is in effect for Nassau and Suffolk counties from 11 a.m. to 11 p.m. Thursday, the National Weather Service said.

Environmental officials predict outdoor air pollution levels will be elevated during that time.

The state health department recommends residents limit strenuous physical activity outside. Young children and those with pre-existing health conditions, such as asthma and heart disease, are at greatest risk, officials say.

The alerts are issued when the air quality index, or AQI, is expected to be greater than 100. The AQI was created as a way to correlate levels of different pollutants to one scale.

The forecast is mostly sunny, with highs in the mid 80s, according to the service.