Hopefully you’re already aware of the basic safety precautions needed when it comes to fireworks, but what you may not know is the associated increase in air pollution that accompanies the loud bangs, pops and hisses, as outlined in a new study.

The team behind a new study led by researchers from Brigham Young University (BYU) in the US found that fireworks are among the three largest sources of particulate matter pollution in Utah’s Wasatch Front region.

Of most concern were the PM2.5 pollutants. At less than 2.5 microns in diameter – a fraction of the width of a human hair – their small size makes them particularly dangerous because of how easily they can be inhaled.

The samples, taken between 2019 and 2021, were analyzed for trace metals to identify sources of pollution. High levels of barium and copper were discovered in fireworks, as were arsenic, cadmium, lead and thallium in winter inversions, where a shift in air temperature traps pollutants.

“We know we breathe in these particles that are unhealthy during fireworks events, dust storms and winter inversions,” said BYU geologist Greg Carling.

“But what is actually in the particulate matter? No one really knew before this study.”

In addition to fireworks, mineral dust and urban pollution were identified as the other two major pollutants in this part of Utah. Any fireworks that produce smoke or color contribute significantly to the problem, the researchers say.

In January and July, peaks in metal pollution in particulate matter were observed, the latter probably due to the fireworks events on Independence Day. In fact, fireworks are banned in the region due to the fire risk, except on two dates in July and on New Year’s Eve.

While it is difficult to quantify the health risks of fireworks and air pollution, it is certainly not good. Air pollution has previously been linked to problems such as asthma, pneumonia and cardiovascular disease.

“Metals are very good at moving from the atmosphere to the soil, to the water, to our food,” Carling says. “And they’re persistent, meaning they don’t really disappear – they just keep circulating through the system.”

There’s no doubt that the chemistry behind fireworks is genius, but these holiday symbols must also be considered for the potential damage they cause to the environment.

The researchers urge Utahns to refrain from in-person fireworks displays and to adhere to municipal meetings, and to avoid being outdoors during pollution peaks. They also want to raise awareness of potential dangers at the government level.

“It’s great when research leads to legislation that can help improve things,” Carling says. “Sometimes it’s just a paper that gets published and a few scientists read it. But other times it gets picked up and used to create real solutions.”

The research was published in Applied Geochemistry.