July 4th fireworks are partly responsible for NYC’s bad air quality

If it hurts to breathe right now, you’ve got fireworks to thank. The Fourth of July festivities filled the air with small airborne particle pollution, known as PM2.5.

Data from city sensors shows a precipitous spike in PM2.5 concentration, peaking Thursday night amid the rockets’ red glare and pyrotechnics bursting in air.

The particles’ small size makes them especially dangerous when inhaled, according to the American Lung Association. Exposure can cause breathing problems and even send some people to the hospital.

Sensors over the BQE, in Staten Island’s Port Richmond neighborhood and on the Manhattan Bridge all recorded PM2.5 concentrations in excess of federal air quality standards over the last 24 hours.

“This is due to fireworks,” the city’s Emergency Management department posted on X Friday morning. City officials expect the concentrations to decline over the course of the day.

While the city data shows the particulate matter concentrations have declined since last night, the Environmental Protection Agency still lists NYC’s air quality as unhealthy for sensitive groups.

That’s partially thanks to the hot and humid weather Friday, which helps trap vehicle exhaust and other emissions in the air. Ozone forms when vehicle emissions react with sunlight. The state Department of Environmental Conservation issued a health advisory Friday morning linked to high ozone concentrations.

The bad air may be especially taxing for people with heart or breathing problems to spend extended time outside. Older adults, pregnant New Yorkers and children are also vulnerable.

These maps and charts will update throughout the day, so check back regularly to see when the air is safe again. In the meantime, people who are vulnerable to air pollution should stay indoors if they can and wear a well-fitting face mask when outside, according to the state health department .

Last year’s fireworks show was even more hazardous to human health, Gothamist reported previously. The pollution was on par with that of the Canadian wildfires that tinted NYC skies orange last June.