'Near-miss for a plane, worst air on Earth': How America's record 850,000-firework show turned toxic

The biggest — and most damaging — fireworks display in history.

Hundreds of thousands of shells exploded overhead, a thick haze of smoke blotted out the sky, and noise echoed like a war zone.

The scene was the largest fireworks display ever staged on Earth. But not everyone in the crowd was cheering. Concern over the wide-ranging side effects of fireworks ran high.

Those concerns proved well-founded. As smoke laced with heavy metals poured across the city, air pollution levels soared to among the worst ever recorded anywhere in the world.

The damage was not short-lived. Elevated air pollution in the surrounding area persisted through the following day, leaving all residents exposed to air quality levels deemed harmful to health.

A passenger jet approaching a nearby airport was also struck by fireworks, narrowly averting what could have been a catastrophic accident.

On top of that, the toll on birds from the display was difficult to quantify. All of it was the consequence of pressing ahead with the largest fireworks show in history — one that experts say offered nothing but harm to the environment.

Despite widespread warnings about air pollution and safety risks, the US government went ahead Saturday with the largest fireworks display in the history of the planet to mark the 250th anniversary of Independence Day. Some 850,000 shells were fired over Washington, D.C.

The United States holds fireworks displays every year on Independence Day, but this year's event was on an entirely different scale. The 850,000 shells represented an increase of roughly 12,000 percent compared to last year — a record not just for the United States, but for the entire world.

A fireworks display is not simply a light show. Each burst is, in effect, a small explosion, releasing metallic particles and soot — including sulfates, nitrates and organic compounds. Ultrafine particulate matter invisible to the naked eye is also known to blanket the sky.

Warnings had been raised before the event. The National Park Service (NPS) had flagged the risks through internal modeling data, and those findings were reported in US media. The NPS specifically warned that fireworks could produce "dangerous levels of air pollution" lasting three to six hours in the surrounding area.

Under the most likely scenario, fine particulate matter (PM2.5) concentrations near the venue were projected to reach 600 to 1,200 micrograms per cubic meter; in a worst-case scenario, levels could exceed 2,000 micrograms per cubic meter. Both figures exceed the PM2.5 concentrations typically recorded in areas affected by large wildfires.

Those fears were realized. According to IQAir, a Swiss air quality monitoring firm, Washington, D.C., recorded the highest air pollution levels of any city in the world between 3 and 5 a.m. Saturday, in the immediate aftermath of the fireworks.

The deterioration in air quality began Saturday afternoon as fireworks started going off sporadically, then spiked sharply around midnight when the main event got underway. PM2.5 readings soared to 200 micrograms per cubic meter, reaching levels classified as harmful to human health.

One reason fireworks are considered particularly dangerous is that the particles they release are not ordinary dust but a chemical mixture. Metal salts are used to produce colors, and the explosion and combustion process generates a range of ions and organic compounds.

Research conducted during China's 2025 Lunar New Year period found that PM2.5 levels during fireworks activity rose between 10.5 and 226.4 percent compared to the period before, with significant increases in secondary inorganic aerosols — including sulfates, nitrates and ammonium — as well as fireworks-specific markers such as potassium and chloride.

Research on the air pollution caused by fireworks has also been conducted in South Korea. A research team led by Choi Yun-hyung, a professor at Korea University's School of Health and Environmental Science, found that fine dust levels rose by as much as 32 times following large-scale fireworks festivals held in Seoul and Busan.

Water pollution is another significant concern. Fireworks and firecracker debris contains incompletely burned fuel, additives, metal salts and packaging residue. These remnants ultimately wash into rivers and lakes, where they can affect microbial activity and aquatic life. The concern grows when fireworks are repeatedly held in the same location.

The most direct harm cited is the impact on birds. When sudden loud noise and bright light erupt nearby, birds do not merely deviate from their usual flight paths — they can lose the ability to find a new one altogether. Disoriented birds may then collide with buildings and other structures, with the potential for mass die-offs.

In early 2021, hundreds of birds were found dead on a street in Rome following a large fireworks display, drawing widespread attention. OPA, an animal protection group that shared photographs of the scene, criticized it as "the horrific consequences of fireworks."

The geographic reach of fireworks-related bird harm is also vast. Research by Professor Bart Hoekstra of the University of Amsterdam found that birds can be affected by New Year's fireworks from as far as 10 kilometers away. The team also confirmed that in one specific study area alone, 400,000 birds took flight as a result of fireworks.

Against this backdrop, a growing number of countries have moved to restrict or ban fireworks — including their purchase. The Netherlands this year introduced a blanket ban on the purchase and use of fireworks by private citizens. Germany strictly limits consumer sales to a four-day window at the end of each year.

Meanwhile, the Independence Day celebrations also raised safety concerns beyond environmental damage. A passenger jet preparing to land at a nearby airport was struck by fireworks during the display. The collision occurred at an altitude of just 60 meters, raising the prospect of a major disaster.