Particulate levels 6.7 times pre-fireworks baseline
Residents of Washington, D.C., on Sunday briefly experienced the worst air quality of any major city in the world, according to AirNow, the Environmental Protection Agency website that reports air quality measurements, as the capital reckoned with the aftermath of a massive Independence Day fireworks show.
Hourly concentrations of particulate matter rose to 6.7 times their pre-fireworks levels, according to a Tuesday analysis from the company Clarity Movement based on its network of 26 air quality sensors throughout the city in partnership with the local department of energy and environment. Every one of those sensors reached air quality levels that the EPA deems “unhealthy for sensitive groups” during the event, the researchers found, with some recording even worse levels of emissions. Levels of particulate matter peaked at 4 a.m. on Sunday, approximately five hours after the display concluded, and remained elevated for approximately five hours after reaching its peak.
City officials declared a Code Red alert. “Outdoor air quality is unhealthy for seniors, kids, people with medical conditions,” the alert said. “General public may experience health issues. Limit time outside.”
The southwest region of D.C. experienced the highest pollution levels, the report’s authors found, probably because of its proximity to one of the fireworks launch sites in West Potomac Park, as well as overnight meteorological conditions that trapped smoke over the area. That highly polluted air likely drifted into Arlington, Virginia, said David Lu, CEO and co-founder of Clarity Movement.
“Unfortunately, we don’t have sensors there to confirm it,” Lu said. “That’s exactly why expanding real-time air quality monitoring matters. Without comprehensive coverage, communities can be exposed to significant pollution events that go undetected.”
The air quality across the city could have been even worse if not for thunderstorms that struck the city Sunday evening. “Despite the scale of the fireworks display, the city’s air quality avoided a worst-case scenario thanks to favorable weather conditions and the timing of the event,” said Lu.
MSI previously reported that the city’s July 4 fireworks display would be the largest in D.C. history and would start significantly later than usual, organized through Freedom 250, the public-private partnership established by the Trump administration for the semiquincentennial. The July 4 show began at 11 p.m. on Saturday evening and involved more than 850,000 fireworks launched from 10 sites across the capital, the organizers said. A typical Independence Day show in D.C. involves just 17,000 shells.
President Donald Trump on social media called the show “the Most Spectacular Fireworks Show I have ever seen, and I’ve seen them all.” Asked to comment, White House spokesperson Taylor Rogers said: “It was the largest and greatest firework display in the history of our country to properly celebrate America’s 250th birthday! Every year, fireworks on the Fourth of July cause short-term spikes in air quality across the United States, including Washington, DC. This was not unique to the 250th fireworks celebrations in our nation’s capital.”
Americans shoot nearly 300 million pounds of fireworks into the atmosphere every year, according to the American Lung Association, releasing lung-harming gases such as sulfur dioxide, carbon dioxide and carbon monoxide. The Trump administration has, since re-entering office, engaged in a wide-ranging rollback of pollution controls, exempting polluting facilities from emissions regulations, boosting coal power, and halting the consideration of the value of lives saved when restricting fine particulate matter and ozone. On July 4, the president also pardoned nine individuals convicted of violations related to the Clean Air Act, including people found to have tampered with emissions control equipment in cars or selling parts to bypass air pollution standards.