As the United States celebrates its 250th anniversary, fireworks displays are expected to bring more glitz and atmosphere than ever before. But with bigger festivities and domes of blistering heat expected, millions of Americans could face double the amount of massive amounts of unhealthy air.
Every year on Independence Day, the country’s fireworks range from impromptu streetside celebrations to formal rocket shows, creating smoke pollution that sometimes rivals that from wildfires and can last for hours. In some cities, air quality often doesn’t return to normal until around noon the next day, and suffocating weather can encourage this wandering.
But experts say smoke from this year’s larger-than-usual Memorial Day celebrations could increase respiratory risks in a region already suffering from poor air quality due to record temperatures this week.
Even before fireworks are set off in some urban areas, the heat can already create another type of air pollution: ozone. Scorching heat locations, such as Washington, D.C., which hosts record fireworks displays, are expected to experience at least moderate amounts of ground-level ozone during the day. This pollutant is typically produced when chemicals from car exhaust are baked under strong ultraviolet light on hot days.
More than 50 million people are expected to experience triple-digit temperatures this week, with at least 100 record highs expected by Saturday, mostly on the East Coast.
“I like fireworks. I’m a patriot. I think fireworks are fun. It’s worth it to get a little bit of dust in the air,” said Russell Dickerson, a professor in the Department of Atmospheric and Oceanic Sciences at the University of Maryland, College Park. “But this Fourth of July is going to be bad for several reasons.”
To celebrate 250 years of freedom, many cities are truly commemorating the red glow of rockets and bombs exploding in the air in historic ways.
The grandest celebration will be held in the nation’s capital, with 850,000 fireworks set to be set off in just 40 minutes from 10 venues around Washington, DC, setting a Guinness World Record for the largest fireworks display. The current benchmark is the 810,904 fireworks during the 2016 New Year countdown celebration in the Philippines. The spectacle in the nation’s capital will be about 10 times larger than New York’s Macy’s Fourth of July fireworks show, which is usually the biggest Fourth of July celebration.
New York City also plans to supersize the show, setting a local record by setting off 85,000 fireworks in 30 different colors. Nashville aims to set off an unprecedented number of fireworks, thousands of them. Boston will choreograph live music to the display. Charlotte has announced the largest fireworks display in the Southeast at its baseball stadium. This will be the third time in San Francisco’s history that fireworks will be launched from the Golden Gate Bridge.
But fireworks extravaganzas cause problems in the air, quickly emitting smoke and microscopic pollutants known as particulate matter (PM) 2.5. They are about one-thirtieth the width of a human hair and can cause respiratory problems and worsen heart conditions. Part of PM 2.5 is made up of the metals that give fireworks their colors and can lodge deep in your lungs, causing irritation, coughing, and shortness of breath.
Researchers found that these small pollutants increased by about 42% in the hours after a fireworks show.
However, in previous years, the extravaganza was not as large as this year’s, and air quality immediately after the show was a major concern.
“We know that in any city in the country that hosts a fireworks display, the level of particulate matter increases tremendously as soon as the fireworks display begins,” Dan Jaffe, a professor of environmental chemistry at the University of Washington, told CNN. “Emissions will be an issue. As the number of fireworks increases, so will the amount of PM 2.5 in the air.”
Be aware of heat domes, ozone, and the possibility of rain
To make matters worse, many locations for large-scale fireworks displays will also experience historic heat. High-pressure areas known as heat domes will be planted across much of the country this week, restricting winds and trapping hot air close to the ground.
Washington, D.C., is expected to reach around 102 degrees for the hottest July 4th on record. New York is expected to reach triple digits between Thursday and Saturday for the first time in a decade. Philadelphia could tie Saturday’s second-hottest temperature on record at 104 degrees. Boston may experience its warmest day and night on Independence Day.
Dickerson said stagnant air could trap smoke closer to the ground for longer than normal and could even make fireworks harder to see. In 2019, a similar situation tarnished Washington, D.C.’s bright shine. Dickerson said warmer temperatures will cause people to use their air conditioners more heavily, consuming more energy, and increase PM 2.5 in the air.
“You won’t be able to see more than 100 yards,” Dickerson said. “If the winds are stagnant, such as at sunset on a hot day, it is very likely that the plume will take hours or even days to completely dissipate.”
Then there’s ozone. Many people remember it as the upper gas in the atmosphere that protects the Earth from the sun’s intense rays. But ground-level ozone, formed from a mix of car exhaust, heat and sunlight, can irritate the lungs and worsen air quality ahead of the evening’s celebrations.
“Heat exacerbates this whole problem, so ozone concentrations are typically highest when temperatures are in the high 80s to low 90s in most locations,” Jaffe said. “If you think about urban areas across the United States, warmer cities generally tend to have more severe ozone pollution.”
And if firework particles remain into the next day, the chemicals in the fireworks can also react with sunlight, increasing the ozone risk on July 5, Jaffe said.
Dickerson, who is based in Maryland, said Saturday didn’t seem like a good day to attempt a world record. “It’s not possible this year, but I won’t be taking my grandchildren,” he added.
Rain could help reduce heat and air pollution. As of late Thursday, storms were expected to develop from Virginia into New England late Saturday afternoon and evening. The rain could help reduce ozone pollution during the day, including in the capital, but the showers are likely to end before washing away firework smoke that night. In Washington, DC, rain is not expected to return until around the next afternoon.
When the air quality index reaches “unhealthy” levels above 100, the Environmental Protection Agency advises people who are pregnant, have pre-existing conditions such as asthma, or are around young children or the elderly to use caution. When air quality becomes dangerous and the index exceeds 300, everyone is likely to be affected. People can wear proper N95 masks to limit exposure to contaminants.
