Smoke and haze covers Old Country Road and Glen Cove Road in Carle...

Smoke and haze covers Old Country Road and Glen Cove Road in Carle Place earlier this month. Credit: Howard Schnapp

Long Island’s air quality could worsen later this week to hazardous levels, but it’s not expected to be as bad as what darkened the skies earlier this month.

Gov. Kathy Hochul on Tuesday warned that smoke rolling down from Canadian wildfires could bring unhealthy air conditions to much of the state by Thursday, and the state’s top environmental official said that the haze could hit New York City and Long Island.

Authorities predict the air quality index will be 50-100, considered moderate, for much of Long Island Wednesday, but are “increasingly confident” it could hit 100-150 Thursday, with possible spikes of worse air quality, said Basil Seggos, Department of Environmental Conservation commissioner, in a news conference on Tuesday.

At the 100-150 level, members of sensitive groups, like people with asthma or other cardiovascular conditions, may experience health effects from breathing in the tiny particles in the smoke known as PM2.5. Higher than 150 is unhealthy for everyone, and people should consider staying inside with windows closed or wearing an N95 mask outside, officials said. Local air quality numbers are available at a federal website,

“We are urging people to limit outdoor activity,” Seggos said.

Smoke prediction is unreliable beyond 48 hours, he added, and it was unclear how the smoke plume — currently in the Upper Midwest — could affect the Fourth of July holiday weekend. Officials said they are likely on Wednesday to issue an update for Friday and Saturday.

Earlier, Hochul, speaking at an unrelated Manhattan event, told reporters that the smoke would reach Western and Central New York first, but that air quality was deteriorating and “we're anticipating the smoke and the haze to come all across the state.”

Joe Pollina, a meteorologist at the National Weather Service’s Upton office, said weather watchers “are not expecting the flow to be as strong as it was” in early June because the low pressure system associated with the wind carrying the smoke is weaker. The smoke plume from Eastern Canada now shows on satellite imagery as moving toward Illinois, with a low pressure system poised to change wind direction, putting New York State in the crosshairs.

The dense smoke will be to our west, James Tomasini, a weather service meteorologist, said early Wednesday morning.

Authorities will issue air quality warnings on public transit and highway message boards, and N95-style masks will be distributed at locations including Penn Station, Grand Central and Jamaica Station, according to a release from Hochul's office. 

A smoke event in early June shrouded parts of Long Island and New York City in orange haze and may have contributed to a spike in emergency department visits, according to state Department of Health Commissioner James McDonald.

The PM2.5 particles in the smoke are dangerous to breathe because they are less than 2.5 microns in width and can penetrate lungs. According to the Department of Health, exposure can affect heart and lung function, worsening some medical conditions and increasing the risk for heart attack.

Studies have linked daily exposure to increased hospital admissions and deaths and suggest that long-term exposure to the particles may be linked to increased rates of chronic bronchitis, reduced lung function, and lung cancer. Exposure can also cause short-term effects such as eye, nose, throat and lung irritation, coughing, sneezing, runny nose and shortness of breath.

The Canadian wildfires are among the worst in recent memory. There are currently 484 active fires, 254 of them out of control.

With Matthew Chayes

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