NYC’s air quality after July 4th fireworks was as bad as wildfire pollution

New York City’s air quality spiked to hazardous levels early Wednesday morning following the Macy’s fireworks display and other Independence Day celebrations, raising questions about whether a beloved annual tradition should continue in the face of growing concerns over air pollution.

Air quality has been front of mind for New Yorkers as Canadian wildfires spewed smoke over the Northeast in recent weeks. But a spike in fine particulate matter (PM2.5) late Tuesday and early Wednesday was more of a self-inflicted issue, researchers said.

Along the East River, a team of NYU graduate students recorded up to 3,300 micrograms of particulate matter per cubic meter volume of air in the aftermath of the fireworks display. Anything greater than 500 micrograms per cubic meter is considered extremely dangerous in the short term, according to the U.S. Department of Environmental Protection website AirNow.gov.

“It really affected air quality last night,” said Dr. Terry Gordon, an NYU professor of medicine who led the team and researches the health impacts of inhaled pollutants, referring to the fireworks show.

After the first 10 to 15 minutes, students saw fine particle pollution skyrocket, specifically in areas closest to fireworks.

“They started saying, ‘It’s going up, it’s going up,’” Gordon said.

Around 1 a.m. Wednesday, the air quality index climbed to 434 citywide. Anything above 301 is considered hazardous, which should trigger emergency warnings urging people to stay indoors and limit outdoor activities.

The city’s own air quality sensors showed high levels of small particle pollution across the city starting at 7 p.m. on Tuesday and continuing until 2 a.m. on Wednesday. Air quality conditions gradually began to improve but were still teetering at unhealthy levels around 7 a.m.