Washington D.C. Receives Purple Air Quality Alert After July 4 Fireworks

And surrounding areas received a purple air quality alert on Sunday, corresponding to very unhealthy pollution levels. The Metropolitan Washington Council of Governments issued the alert for the capital and parts of northern Virginia, warning that any outdoor exposure could carry health consequences for sensitive groups. Suburban areas around D.C.

Received orange alerts, indicating conditions unhealthy for sensitive groups, while parts of Maryland were assigned yellow alerts for moderate pollution. A heat advisory remained in place for D.C. and nearby sections of Maryland and Virginia until 8 p.m.

ET on Sunday. , ranked sixth among the world's most polluted cities on Sunday, according to IQAir. Pakistan's Lahore ranked first and Congo's Kinshasa ranked second, followed by Jakarta, Jerusalem and Tel Aviv.

Detroit briefly ranked as the world's most polluted city early Sunday morning, while Chicago and Minneapolis neared the top of the list. Researchers connected the pollution shift to massive fireworks displays held across the United States on Saturday night.

The capital staged an especially elaborate Fourth of July spectacle to commemorate both the holiday and the 250th anniversary of American independence.

Air quality in the region began to improve on Monday and was expected to return steadily to normal throughout the week.