Some people love them. Some people hate them. They’re noisy, can frighten pets and wildlife and be traumatic for some people. But no matter what, fireworks are as much a part of Fourth of July festivities as hot weather, trips to the beach and backyard barbecues.
According to the American Pyrotechnics Association, Americans bought more than 416 million pounds of consumer fireworks in 2021 and another 12.5 million pounds in professional fireworks. They’re obviously not going away anytime soon.
When it comes to fireworks, there’s more than the noise to worry about. The impacts to humans, wildlife and the environment can be substantial.
Fireworks leave a cocktail of chemicals in their wake. The vivid colors are the result of metallic compounds that include barium and aluminum. Perchlorate, a chemical compound containing chlorine and oxygen, is added to fireworks to provide the oxygen needed for an explosion.
The National Institutes of Health said pollutants, especially sulfur dioxide and carbon monoxide, can affect respiratory health. Chlorine can act as an irritant, affecting the eyes and nose and cause a burning sensation, coughing, blurred vision and tightness in the chest. High levels of perchlorates can affect the thyroid gland.
Eric Lambert, from Clark County Public Works’ clean water division, said more studies are needed to understand how these chemicals are affecting our environment.
“What we say is, ‘Only rain down the drain,’” Lambert said Wednesday. “There’s not a whole lot of research on the actual impacts regarding heavy metals, regarding the perchlorate.”
The Environmental Protection Agency awarded a $2.5 million grant to Texas Tech University in 2023 to study how the use of fireworks could impact water supplies. The research is expected to wrap up in 2026.
“Hopefully, we learn more after that study concludes,” Lambert said.
In 2009, Snohomish County had a pilot study of fireworks pollutants at local water sources. That study found low levels of perchlorate in two bodies of water following Fourth of July celebrations, although neither was used as a source for drinking water.
Other chemicals found in fireworks include copper, magnesium and strontium.
“We have street sweepers that go around neighborhoods and sweep, but those aren’t going to be going around on July 5,” Lambert said. “It’s really important for people, if they are using fireworks on the Fourth of July, to be cleaning up afterward.”
Used fireworks left on the ground can end up washing down stormwater drains days, weeks or even months later. That means the plastic, paper and other debris left over is carried away along with the heavy metals and perchlorate.
Lambert said it’s important to remember that stormwater runoff isn’t diverted to a water treatment plant but instead flows directly to a stream or other body of water.
“Those are things we definitely don’t want in our stormwater,” he said.
Once the spent fireworks are swept up, they should be placed in a bucket of water to ensure they are extinguished before being placed in a garbage can or waste bin.
“You can pour that water out over a landscaped area so it’s not going right back down to the storm drain,” Lambert said.
