Why Fireworks Can Be Bad for Our Brains

Each year, people in the United States set off roughly 400 million pounds of fireworks. While these create spectacular shows, a host of recent research has called attention to the risks posed by the widespread use of these explosives.

Fireworks immediately and significantly increase air pollutants linked to dementia, depression, violence and more. Here’s the important science behind how fireworks may harm our brains, and what we should consider moving forward.

Fireworks have been in use for about 2,000 years, since their invention in China. But modern multi-colour fireworks are a far more recent occurrence. By adding metals like barium and aluminium to the explosives, current fireworks can generate a mesmerising kaleidoscopic display. But when the lights dim and the crowd begins to dissipate, the afterglow of these pyrotechnics starts to settle in. What’s left of the tons of explosives is tiny particles that float across the air, settling in our lungs, getting into our bloodstream and eventually, creating harm in our brains.

Powerful research published over the last decades proves that air pollution is a direct, immediate and lasting effect of fireworks displays. This can be seen during the Indian holiday of Diwali, during the Chinese Spring festival and around the world during New Year celebrations. In the US, the biggest days of the year for fireworks are the Fourth of July and New Year’s Eve.

It’s often stated that fireworks can lead to psychological stress for a subset of people more sensitive to loud explosions. But everyone who breathes in the air pollution generated by these displays is at risk for worse health. At a national level, air pollution is known to increase dramatically on major fireworks holidays and stays elevated well into the next day. One study looked at over 300 sites across the United States and found that after fireworks, particulate matter of 2.5 microns or smaller (PM 2.5) increased by 42% overall (up to 370% in locations closer to fireworks displays) and stayed elevated until noon the next day.

More recent research suggests even higher levels of air pollution attributable to fireworks. In a 2022 study conducted in Minneapolis, Minnesota, researchers used air pollution sensors that measured particulate matter and gases before, during and after a downtown July 4th fireworks display. Compared to July 3rd, researchers found an up to 600% increase in PM. These types of results can also be seen internationally, with a recent 2025 paper showing an increase in peak PM levels over 12 times higher after firework festivals in Korean cities compared to other days.

One criticism of the significance of this type of research concerns the relative dose. Air pollution does vary each day, and some might argue that the increase attributable to fireworks is relatively inconsequential. Yet a host of research is demonstrating that even one day of increased air pollution exposure is worth avoiding.

Few will be surprised to learn that acute exposures to air pollution can exacerbate lung diseases like asthma or COPD. But now we’re learning that these negative effects extend to the brain. In a 2025 paper in Nature Communications, researchers wanted to see if air pollution could acutely impact people’s cognitive abilities. Compared to those breathing clean air, people who inhaled higher levels of air pollution tested lower on multiple cognitive tests four hours after exposure. And while it’s well established that long-term exposure to air pollution correlates with higher risk for mental health issues like depression, recent work suggests that day-to-day mood is significantly impacted by air quality. Perhaps even more concerning, these same small changes in air pollution each day are also associated with more violent crime.

Air pollution is uniquely problematic to brain health for several reasons. First, it’s largely invisible, and often doesn’t rise to the level of conscious concern. Next, air pollution (in particular PM 2.5) appears to have a highly unhealthy influence on the immune system, raising inflammation throughout the body and activating the brain’s immune cells towards a damaging state. But while pollution sources like wildfires and traffic can seem tough to completely avoid, fireworks are an optional add-on to celebrations, and there are practical ways to mitigate this risk.

At the level of an individual, one can significantly decrease exposure by positioning themselves upwind and further away from fireworks displays, if they choose to participate. Laser, glow sticks, noisemakers and confetti poppers are other ways to celebrate around the home. More systemically, there’s been a move in several countries to promote drone-based displays in place of conventional pyrotechnics (some are quite spectacular).

The core challenge to all of this comes down to a question of priorities. For many, fireworks are a critical part of what it means to celebrate, and any alternative is worthy of ridicule and is an immediate non-starter. In some ways, the conversation is akin to alcohol consumption, fraught with strong opinions opposed to any departure from the real thing. Yet as the science continues to evolve, we should at the very least be aware that fireworks come with a real trade-off to our health and especially, our brains.