The National Park Service on Saturday will launch over 850,000 fireworks into the skies of Washington, bathing the capital in patriotic blasts of light for the nation’s 250th birthday.
Then comes the fallout.
Scientists have well documented the soot and heavy metal pollution that can spike severely in the wake of pyrotechnic displays, and the world-record-setting number of fireworks lined up for July 4 will mean an equally large jump in pollution, experts said. Last year, according to the National Park Service, Washington’s display set off just 7,000 fireworks. Multiplying that by 120 could also deposit into the Potomac River water pollutants like perchlorates and heavy metals, the effects of which on humans and the environment are still not well understood by scientists.
“I wish I could have got a team in D.C. to do all this stuff,” said Terry Gordon, a semi-retired research professor at New York University’s Grossman School of Medicine.
By “all this stuff,” he’s referring to a study he did three years ago that sent a dozen students scurrying around New York on July 4 to sample the air and water (which required “sweet-talking” cops for access to the East River) before and after the Macy’s fireworks display.
The results were eye-popping. Two of their air samplers saw fine particulate matter — soot and smoke particles so small they can be inhaled into lung tissue and enter the bloodstream — jump from a range of 10 to 15 micrograms per cubic meter to over 1,000 micrograms. A third site shot past 3,000 micrograms. The national standard over a 24-hour period set by EPA is 35 micrograms, and just 9 micrograms averaged annually.
That 2023 Macy’s spectacular fired off 60,000 fireworks. Washington will see 851,000 — more than 14 times as many — light up its skies.
Gordon said he wanted to study this year’s Washington extravaganza, but most of his students have graduated and he figured tight security around the city would make access impossible.
“This event coming up is a great natural experiment, let’s say, to see what would happen,” said David Luglio, one of Gordon’s students on the Macy’s study who is now a postdoctoral fellow at Tulane University. “Because if it is over 800,000 fireworks, I can’t imagine what that’s going to do to the air quality.”
The good news is that the dirty air doesn’t linger too long. One study found that particulatematter from July Fourth fireworks remained elevated for about 24 hours across 315 different monitoring sites. On average, the fireworks displays increased pollution by 42 percent. But after a day, fireworks pollution dissipates and usually blows away or settles into water and soil within a day.
“The question is: Are they the same or more toxic than the regular old fossil fuel combustion particles you might be breathing in day after day after day?” said Gordon, referring to common sources of pollution like vehicles and power plants. “That’s unclear.”
The National Park Service and Freedom 250, the Trump-aligned organization helping plan the event, didn’t respond to requests for comment. In response to questions about potential spikes in air pollution, EPA spokesperson Mike Bastasch said Washington has jurisdiction over the city’s air quality.
“First off, fireworks are awesome and we hope everyone enjoys the incredible shows in and around our nation’s capital as we celebrate 250 years of America,” Bastasch said in an email. “The EPA is not issuing permits for the fireworks for this event.”
Washington isn’t the only location beefing up their fireworks displays this year. Nashville is preparing its largest celebration ever, according to the American Pyrotechnics Association, and San Francisco is planning to shoot fireworks from the Golden Gate Bridge for just the third time in history. Mount Rushmore will also host an elaborate fireworks display for the first time since 2020.
This year’s festivities will coincide with a severe drought in Washington and 100-degree temperatures Thursday through Saturday. Washington-based utility DC Water is coordinating with the federal government to ensure there’s water available in the event of fires, as residents are known to set fireworks of their own.
“Our Incident Management Team is preparing to monitor conditions and will activate for the Fourth of July events, with field staff strategically staged to respond as needed,” DC Water spokesperson Sherri Lewis said in an email.
Unlike in years’ past, the fireworks are not just on the National Mall. Some will also be shot off eight Potomac River barges and from West Potomac Park.
The drought means that pollutants may linger longer in the Potomac than they would under normal conditions, said Tyler Frankel, an associate environmental science professor at the University of Mary Washington. Contaminants can easily get trapped in the river near Theodore Roosevelt Island due to “tidal slosh,” a phenomenon where the water flows both upstream and downstream, Frankel said.
Amphibians and juvenile fish are particularly vulnerable to perchlorates, compounds used in fireworks to enable a rapid burn but that can also disrupt animals’ developmental processes.
“Even though we’ve gotten some significant rainfall, we’re still under drought conditions,” Frankel said. “The idea of this stuff getting flushed downstream to decrease the concentrations and mitigate effects, the time it takes to have that happen is being extended.”
Other animals at risk include ospreys, iconic fish-eating birds that are currently in the midst of breeding season and are easily spooked by loud noises.
The Chesapeake Bay region contains 20 percent of the world’s ospreys, but the population has declined in recent years, said Joanie Millward, executive director of the Virginia Osprey Foundation. When fireworks are set off, frightened ospreys often flee their nests, leaving chicks at risk of being eaten by predators, Millward said.
“At best, it places a lot of stress on them. At worst, it can cause death,” she said.
Health risks and ‘skyrocketing pollution’
Fireworks also rain down small but potentially potent amounts of heavy metals that are used to create vibrant colors but also pose serious health risks.
A 2020 study conducted by Gordon found a “disturbing amount” of lead in the exhaust from some types of fireworks sold to individuals for home use. Consumer fireworks made up the vast majority of products sold in 2025 — almost 300 million pounds, versus 23.5 million pounds of “display” fireworks, according to the American Pyrotechnics Association. Overall fireworks consumption has more than doubled over the past 25 years.
There’s ample research on the air quality impacts of fireworks from around the world — including Diwali celebrations in India, summer religious festivals in Malta and a Guy Fawkes Day observance in New Zealand. But much less is known about exactly what kind of public health impacts follow.
No one has yet done epidemiological studies to look at whether hospital admissions for asthma or other cardiovascular and respiratory ailments increase after fireworks events, the kind of research that has been performed on wildfire smoke and ambient pollution.
Gordon unsuccessfully sought a grant from the National Institutes of Health to do just that some years ago. But interest apparently remains; a government official contacted Gordon last week asking about whether such a study was feasible. He declined to say who, or even identify the agency, out of fear they would face retaliation.
“We got jumped on [for] being so unpatriotic,” Gordon said of the Macy’s fireworks study. “And that was the opposite. … We all love fireworks. That’s why we had different funny names for the paper.” (The title they settled on? “Skyrocketing pollution.”)
There are a few steps people can take to protect themselves from fireworks-related pollution, experts said.
Observing the show from a greater distance would reduce exposure. So would staying inside and keeping windows closed. An indoor air filter will scrub out particles. And all those N95 masks left lying around from the pandemic would be effective, too.
But that’s not necessarily enough for those with underlying conditions.
“The 250th celebration is exciting, I don’t want to deny that for a second,” says the American Lung Association’s Laura Kate Bender. “But with more fireworks comes more health risks. Bigger shows put more smoke in the air.”
Sam Schmitz knows that all too well. An organizer with Moms Clean Air Force who also has asthma, Schmitz spent last July Fourth “inside with a mask on, leaning over my air purifier struggling to breathe and weighing if I needed to go to the hospital.”
Past Independence Day celebrations have sent her to the emergency room, so this year, she’s not taking any chances with the exponentially bigger fireworks display. She’s booked a hotel room in Gaithersburg, Maryland, in the hopes she will be safely away from any smoke.
“I thought about going to New York or Baltimore where I have friends to celebrate with, but given that it’s the 250th, I’m nervous about fireworks in all the major cities this year,” she said.
