Air quality across Washington, D.C., and nearby communities fell sharply on Sunday, prompting health warnings from officials who said even limited time outdoors could pose risks for some residents. Researchers attributed the spike in pollution to the massive fireworks displays that lit up the region Saturday night for July 4 celebrations.
The Metropolitan Washington Council of Governments, a nonprofit organization representing local leaders across the region, issued a “purple” air quality alert for the nation’s capital and portions of northern Virginia.
A purple alert signals “very unhealthy” air. Under that designation, people in sensitive groups are urged to avoid all outdoor physical activity, while the general public is advised against prolonged outdoor exertion. Sensitive groups include people with heart or lung disease, older adults, pregnant people, children and teenagers, outdoor workers, and others who may be more vulnerable to the effects of poor air quality.
Conditions were somewhat less severe in the suburbs around D.C., where an “orange” alert was in place Sunday. That level means the air is unhealthy for sensitive groups, who are advised to “make outdoor activities shorter and less intense,” according to a breakdown of the alert index. Farther from the city, parts of Maryland were under “yellow” alerts, indicating “moderate” pollution that is generally a concern only for people who are unusually sensitive.
Forecasters expect conditions in the capital region to gradually improve over the next several days.
By Sunday, Washington, D.C., ranked as the sixth most polluted major city in the world, according to IQAir, a Swiss air quality technology company that tracks pollution globally. The city ranked behind Lahore, Pakistan, and Kinshasa, Congo, in the top two spots, followed by Jakarta, Jerusalem, and Tel Aviv.
The pollution surge was not limited to the nation’s capital. Across the United States, major metro areas saw air quality deteriorate after July 4 fireworks celebrations, according to IQAir. The company said its maps showed pollution levels rising nationwide from Saturday night into Sunday morning. Detroit briefly topped the company’s global list of most polluted cities early Sunday, while Chicago and Minneapolis also climbed near the top, along with D.C.
Washington staged an especially large Fourth of July celebration this year, marking both the annual holiday and the 250th anniversary of American independence. The city’s schedule of events included what organizers had billed as the largest fireworks display ever held over D.C.
Saturday’s festivities across the U.S. were hampered to varying degrees by a treacherous heat wave that fueled triple-digit temperatures across large swaths of the country, including the capital, where event organizers temporarily paused scheduled programs because of the searing warmth. A heat advisory was in place for D.C., and nearby sections of Maryland and Virginia, until 8 p.m. ET on Sunday, according to the National Weather Service.
