July 4 fireworks emit toxic metals, can cause permanent damage to human cells and animal lungs, research shows

July 4 fireworks emit toxic metals, can cause permanent damage to human cells and animal lungs, research shows
(Getty Images)

Some of America's most favorite Independence Day fireworks emit lead, copper and other toxins into the air, a research team suggests. These metals, which are used to give fireworks their vibrant color, also damage human cells and animal lungs, says the study led by NYU Grossman School of Medicine, New York. 

The researchers found that ‘surprisingly’ highly toxic metals were present at exceedingly high levels in the emissions of some of the tested fireworks. The analysis shows harmful levels of lead in two of 12 types of commercially-available fireworks sampled. Experiments using rodents and human tissue also reveal that lung exposure to particle emissions from five types of firework significantly increased oxidation, a chemical process in the body that can damage or even kill cells if left unchecked, explain the authors. 

“Some consumer fireworks contain high levels of toxic metals and the fireworks industry should do more to ensure that metals such as lead are not used by the manufacturers (the majority are in China). I believe that increased screening and testing of fireworks is needed,” senior author Dr Terry Gordon, professor of environmental medicine at the NYU School of Medicine told MEA WorldWide (MEAWW). 

He explains that while many are careful to protect themselves from injury from explosions, the results of their analysis suggest that inhaling firework smoke may cause longer-term and even permanent damage, a risk that has been largely ignored. “Fireworks are a great cultural element of our celebrations but users of consumer fireworks should be cautious in using them because of the risk for physical injury by the explosions and, now according to our findings, the risk from inhaling metal particles that are emitted by fireworks in producing the colors that we all enjoy,” Dr Gordon told MEAWW. 

The team, which includes experts from Lamont-Doherty Earth Observatory of Columbia University, New York, also analyzed 14 years' worth of air quality samples taken at dozens of sites across the US by the Environmental Protection Agency (EPA) throughout each year. They found that levels of toxic metals were higher in samples taken near July 4 (Independence Day) and New Year's Eve celebrations than at any other time of the year. Along with lead, titanium, strontium, and copper are commonly found in fireworks. Even though people are only exposed to these substances for a short time each year, they are much more toxic than the pollutants we breathe every day, says Dr Gordon. “With July 4th coming, I hope that parents consider the potential toxic effects of inhaled metal-laden particles by children with developing lungs -- this might mean that children should stand up-wind as they enjoy the celebration,” he said. 

Scientists analyzed 14 years' worth of air quality samples taken at dozens of sites across the US and found that levels of toxic metals were higher in samples taken near Independence Day and New Year's Eve celebrations than at any other time of the year. (Getty Images)


Americans buy more than 258 million pounds of fireworks every year, according to the American Pyrotechnics Association. Displays are used not only for holidays, but also at daily events held at amusement parks, rock concerts, and sports venues. To create bright colors, metals are exposed to high temperatures, causing a chemical reaction that gives off a flash of colored light. For example, red fireworks can be made with strontium, and blue ones with copper, says the study published in Particle and Fibre Toxicology. 

“According to the American Pyrotechnics Association, the amount of consumer fireworks (258.4 million pounds) intended for use by the general public (that is, 1.4G explosives) and purchased in the US is more than 10-fold greater than that used for large celebratory fireworks (19.1 million pounds) displayed by pyrotechnic professionals (that is, 1.3G explosives) and, thus, are a significant concern for adverse health effects,” says the report.

The researchers say that to date, the greatest health concern regarding fireworks has been the potential for injury to life and limb due to the explosive force of fireworks. Each year, approximately 10,000 to 25,000 people (predominantly male teenagers) in the US suffer physical and burn injuries, due to fireworks, which include the loss of fingers, limbs, eyesight, and sometimes life, they add. “The environmental effects are also a concern. Yet, even though there has been a large increase in the amount and size of fireworks events, little to no research has investigated the effect of fireworks-generated particles, and their composition, on human health,” says the team.

Metals such as lead, copper, and other toxins are used to give fireworks their vibrant color, say experts. (Getty Images)


The authors believe their study is the first to examine the effects of firework exposure in human cells and living animals, and to test for particles of common firework metals thrown into the atmosphere. For the analysis, the research team collected emissions from a dozen types of fireworks commonly sold in the US. These included the Black Cuckoo, the Color Changing Wheel, and the Blue Storm firecracker, which they detonated in a chamber in the lab. Then, they exposed human lung cells and several dozen mice to the captured particles, notably in low doses thought to match a New Yorker's daily exposure to pollutants in Manhattan air. The findings show that Black Cuckoo, a fountain-style firework, was found to be the most toxic of the group, at 10 times more damaging to human cells than a non-toxic saline solution.

“These findings demonstrate that pyrotechnic display particles can produce adverse effects in mammalian cells and lungs, thus suggesting that further research is needed to expand our understanding of the contribution of metal content to the adverse health effects of fireworks particles. This information will lead to the manufacture of safer fireworks,” says the study.

The researchers caution that the current investigation is the first step, only addressing the potential effects of a one-time exposure to the fireworks metals. Repeated exposure is likely a larger concern, they emphasize. The team now plans to share the study findings with local health officials, fireworks manufacturers, the EPA, and other regulatory agencies to alert them to the potential for harm.

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