Image provided by Jim Strasma via Unsplash.
TL;DR: The Fourth of July is a popular American holiday, but it brings a rise in air pollution. Fireworks release harmful pollutants and can trigger wildfires, while barbecues and increased travel add to the problem. Cleaner celebration options, such as drone shows, eco-friendly fireworks, community displays, and sustainable grilling, can help reduce the impact. Checking local air quality with tools like Clarity’s OpenMap is a good first step toward a safer, healthier holiday.
The Fourth of July is an exciting summer holiday where people lounge by swimming pools, get together with loved ones, and witness glowing night displays. However, amid all the fun, there is a downside: the Fourth of July often comes with increased air pollution. Understanding and mitigating this air pollution allows us to keep this holiday safe and enjoyable for everyone.
Explore the data yourself: Fireworks' impact on air quality in Los Angeles, 2023-2025
This interactive map tracks fine-particle pollution (PM2.5) across the LAUSD Know Your Air Network (roughly 200 Clarity Node-S air sensors spanning Los Angeles from Santa Clarita to Palos Verdes) hour by hour over the Fourth of July. Use the slider or press play to move through the days from July 4–6 and switch between 2023, 2024, and 2025 to compare years.
Each dot is a school-based sensor colored by its US EPA NowCast Air Quality Index, and the chart below traces the network's hourly reading so you can watch the fireworks signature emerge: air quality holds steady through the afternoon, then climbs sharply after dark on the 4th as smoke builds, peaking late that night and lingering into the next morning before slowly clearing. The wind indicator in the lower left shows why the haze settles in: holiday evenings were nearly calm, giving the smoke little chance to disperse. Of the three years, 2025 was the most severe, with the network median pushing well into the "Unhealthy" range and individual sensors spiking far higher.
How fireworks affect air quality
Fireworks are one of the major sources of air pollution every Fourth of July. Each year, Americans set off almost 300 million pounds of fireworks. This adds up to nearly one pound per person living in the United States, with July 4th and the New Year both seeing the most fireworks celebrations.
Each firework carries a host of air pollutants, including carbon dioxide, nitrogen, nitric oxide, carbon monoxide, sulphur dioxide, and particulate matter. These pollutants can impact visibility and negatively affect public health. The South Coast Air Quality Management District warns against the potential cardiovascular and respiratory health effects of fireworks, such as asthma aggravation, decreased lung function, coughing, and even difficulty breathing and heart attacks.
Just how much air pollution do these fireworks produce? Considering the large quantity of fireworks set off over the holiday, the pollution can be quite extensive. A 2022 study in downtown Minneapolis, Minnesota, found that between 10 pm and midnight on July 4th, particle concentrations increased by 180–600% relative to the previous night, while carbon monoxide concentrations similarly increased by 32%.
The video below, by the Coalition for Clean Air, clearly visualizes how air pollution levels changed dramatically across Los Angeles over the course of the 4th and 5th of July, 2024. The timelapse uses data from the network of 200+ Clarity Node-S devices deployed across the Los Angeles Unified School District’s Know Your Air Network.
Another study conducted at 315 US monitoring sites found that, on average, fine particulate matter (PM2.5) levels are elevated by 42% over the 24-hour Fourth of July period. Fine particulate matter can make its way into a person’s lungs and bloodstream, and it has been linked to increased mortality, respiratory disease, cardiovascular disease, and lung cancer. Fortunately, the elevated levels measured in the study on the Fourth of July largely dissipated by noon the next day. However, even short-term exposure to fine particulate matter can have harmful consequences, especially for children, the elderly, and those with preexisting conditions.
What recent research reveals about fireworks and air quality
The evidence that fireworks degrade air quality keeps growing, and the newest studies put hard numbers on just how extreme the spikes can be. A 2024 study in the Journal of Exposure Science & Environmental Epidemiology tracked pollution from Macy's Fourth of July Fireworks show, the largest pyrotechnic event in the United States. Along New York City's East River, background PM2.5 measured 10 to 15 µg/m³, but peak real-time PM2.5 topped 3,000 µg/m³ at one site and passed 1,000 µg/m³ at two others.
That same New York study followed the pollutants into the water. Zinc, lead, antimony, and copper more than doubled in East River samples taken after the show, so fireworks residue settles into waterways as well as the air we breathe.
Fireworks also load the air with heavy metals. A 2025 study in Atmosphere measured particulate metals in Fullerton, California, inside the Los Angeles air basin, during the 2020 and 2021 Independence Day holidays. Hourly particle concentrations at a nearby regulatory monitor passed 500 µg/m³ in 2020, roughly 14 times the EPA 24-hour PM2.5 limit, and the barium, copper, and strontium that give fireworks their colors spiked alongside lead and chromium, two metals linked to cognitive harm in children and to cancer risk.
These spikes are intense but short lived, usually clearing within a day or two, and the exposure is not shared evenly. Research in the Los Angeles basin found that neighborhoods with larger Hispanic populations tended to face higher firework pollution, an environmental justice concern for the communities most affected. The nationwide picture is consistent: the NOAA analysis of 315 U.S. monitoring sites found PM2.5 peaking between 9 and 10 p.m. on July 4, and at one monitor next to a fireworks display concentrations rose 370%.
The problem reaches well beyond the Fourth of July. During the 2026 New Year celebrations in Metro Manila, sensors in the Clarity-powered Breathe Metro Manila network recorded PM2.5 above 350 µg/m³ just after midnight, with levels staying in the hazardous range for more than 12 hours. As Manila Observatory reported, the 24-hour average across monitoring sites reached 104 µg/m³, about seven times the World Health Organization's daily guideline, and indoor readings closely tracked the outdoor spike, a reminder that staying inside offers only partial protection.
Fireworks and the environment
Not only do fireworks harm public health, but they also impact the environment. Nitric oxide and carbon monoxide both indirectly contribute to global warming, while carbon dioxide is a potent greenhouse gas. Fireworks can also leave behind microplastics and perchlorate (a propellant chemical) in waterways and ecosystems long after the celebrations have ended.
Notably, fireworks also have the potential to start wildfires. Between 1980 and 2016, a total of 11,294 wildfires were started by fireworks. Nearly two-thirds (62.6%) of these firework-induced fires occurred during the two-week period encompassing July Fourth. In 2021, Independence Day fireworks started a wildfire that forced almost 100 households to evacuate in Centerville, Utah.
In addition to contributing to global warming and destroying ecosystems and communities, wildfires also degrade air quality up to thousands of miles away from the fire itself.
Mitigating the impact of fireworks
The prospect of a dark and colorless July 4th night sky might seem jarring. Fortunately, there are ways to mitigate the harmful effects of fireworks and enjoyable alternatives to consider.
Some fireworks are more environmentally friendly, using a cleaner nitrogen-based fuel to create explosions that produce less smoke and require less metal content to create vibrant colors. A type of firework known as a green cracker can help reduce particulate matter emissions. You might also consider enjoying a community-based fireworks show, so that you can still enjoy the spectacle while limiting the use of personal fireworks.
There are some great alternatives to fireworks altogether. Certain communities have adopted drone and laser shows, preserving a glowing night sky while foregoing the harmful explosions. On a smaller scale, party poppers, confetti cannons, and bubble guns can make for great replacements.
Other fourth of July air pollutants
Unfortunately, fireworks are not the only things contributing to this holiday’s air pollution. July’s summer heat encourages the production of ozone, which can exacerbate asthma and harm lung capacity.
July Fourth is also the most popular holiday for grilling. The tradition of backyard barbecuing can also affect local air quality, emitting carbon monoxide, nitrogen oxides, particulate matter, and volatile organic compounds. Fortunately, there are some steps that you can take to reduce barbecuing emissions, including choosing a more sustainable grill, picking higher quality charcoal, avoiding lighter fluid (consider using a charcoal chimney instead), and avoiding chemical cleaners.
Travel emissions
Another source of air pollution over the holiday is travel. The Transportation Security Administration (TSA) expects that over 18.5 million people will fly over the upcoming holiday. The American Automobile Association estimates that over 72 million Americans will travel domestically over the same period.
When it comes to air travel, you can reduce your carbon footprint by booking non-stop flights, flying economy, and packing light. Regarding car travel, you can reduce harmful emissions by carpooling, driving efficiently, using fuel-efficient or electric vehicles, and keeping your car well-maintained with regular tune-ups. Consider alternatives to driving when possible.
Looking Forward
However you choose to enjoy the holidays, the first step in reducing air pollution risk is knowing the air quality in your area. Check out Clarity’s OpenMap here, and explore ways to find a solution with us.
