Orange Air Quality Alert issued in Philadelphia region, much of New Jersey Thursday: NWS

PHILADELPHIA (WPVI) -- The National Weather Service has declared an "Orange" air quality alert in the Philadelphia metro area and several New Jersey counties for Thursday.

In Pennsylvania, Bucks, Chester, Delaware, Montgomery, and Philadelphia counties are under the air quality alert.

The New Jersey counties under the air quality alert include Atlantic, Ocean, Burlington, Cape May, Mercer, Monmouth, Salem, Cumberland and Middlesex counties.

An "Orange Alert" means air pollution concentrations within the region may become unhealthy for people of sensitive groups.

Sensitive groups include children, people suffering from asthma, heart disease or other lung diseases, as well as the elderly.

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Those within the group are advised to avoid strenuous activity or exercising outdoors.