Some fireworks can release toxins into the air, study finds

• A new study from NYU found that two of twelve commercially available fireworks had dangerous levels of lead, with Black Cuckoo fireworks being the most toxic.
• Study author Terry Gordon called for more stringent firework testing from the American Fireworks Standards Laboratory.
• The long term effects of being exposed to fireworks are still unknown.

Some commercially available fireworks contain dangerous levels of lead and other toxins, according to a new study.

Researchers at New York University's Grossman School of Medicine bought 12 types of popular, commercially-available fireworks, including the Black Cuckoo, the Color Changing Wheel, and the Blue Storm firecracker.

The team set off the fireworks in a stainless steel chamber, then extracted particles that were small enough to get into the lungs, testing them on rodents and samples of human tissue. They found that two of the fireworks had harmful levels of lead, with the Black Cuckoo fireworks being the most toxic.

With some counties still planning July 4 fireworks celebrations, and the amount of illegal fireworks complaints soaring in cities, the suggestion that long term exposure to fireworks may be damaging was alarming to study author Terry Gordon, professor in the Department of Environmental Medicine at NYU Langone Health.

"I was shocked that there was this much lead in the samples," Gordon told Insider. "There's an American Fireworks Standards Laboratory, and they look like they have a pretty good system for testing fireworks for toxic elements, so I never imagined that manufacturers might be putting lead in firework consumer fireworks to produce a certain color or sound."

The study began when Gordon helped his son to test fireworks for a high school project

The idea for the study, which was published in Particle and Fibre Toxicology Journal, began several years ago, while Gordon was watching a Disney fireworks special with his son, who suggested that testing the fireworks for toxins could be a great high school research project.

"We bought about a dozen types of fireworks and we spent the summer setting them off in chambers in our laboratory at NYU, and collected the particles and then tested them on cells for toxicity," Gordon told Insider.

The high school research project eventually morphed into a project for Gordon and his graduate students, who spent about $100 on 12 different kinds of fireworks at a retail store, and set about lighting them up to test.

There are strict guidelines on toxins in fireworks, but not all fireworks are tested

The American Pyrotechnics Association estimates that Americans buy over 258 million pounds of fireworks annually. Most of the fireworks brought into the United States are from China, and there are hundreds of different types of fireworks.

To create all of the firework's bright colors, small bits of metal are burnt, which causes a chemical reaction that gives off a flash of color and light. Yellow fireworks use sodium nitrate to achieve their color, while red fireworks use strontium.

The fireworks industry has guidelines for keeping toxic metals out of fireworks, but they're not testing all the batches from all the fireworks manufacturers, because that would be near impossible to do. So some imported fireworks often slip through the cracks and go untested.

"If two out of 12 had high levels of lead, that means that we need to do a better job of testing the safety of the fireworks that are being importing into the United States," said Gordon.

There are ways to make fireworks safer, he said, by using compressed air instead of explosives — something the Disney Corporation switched to in 2004, after 50 years as the world's largest consumers of fireworks and a recipient of extensive complaints from residents near Disney parks. The shift to compressed air fireworks prevented explosions near the ground, which had been contaminating the Everglades with chemicals.

No one has really studied the long term effects of being exposed to fireworks

There may be cardiovascular and pulmonary effects associated with long term exposure to fireworks, said Gordon.

Ethically, researchers can't do studies where some people are exposed to fireworks and some aren't. And generally, epidemiologists who study the adverse effects of chemicals in the air exclude July 4 and New Year's Eve because it would warp their results.

But Gordon hopes to study people who are already attending a fireworks show and examine whether they were contaminated with lead, or had a cardiovascular reaction.

Based on his small study, he says, he believes there is reason for concern.

If you're going to a fireworks show, be aware of wind direction

"I love fireworks, even though I joke that this is the least patriotic study ever," said Gordon. "I wouldn't say don't use them but I would tell people to be aware of the wind direction. Let kids enjoy it but make sure they're upwind."

Gordon says he plans to watch the July 4 fireworks if there are any, but probably will not end up doing so. "I usually end up staying home with the dog because he's definitely afraid of fireworks," said Gordon. "But I enjoy fireworks and I hope to enjoy them on July 4."