Heavy smoke blanketed the northeastern United States for a second day on Wednesday, turning the air a yellowish gray and prompting warnings for people to stay indoors and keep windows closed. Smoke is billowing from dozens of wildfires burning across several Canadian provinces. The phenomena reaches as far south as North Carolina and as far west as Ohio, obliterating the skyline and irritating throats. Conditions were particularly bad in parts of central New York, where soot in the air was at dangerous levels.
Heavy smoke blanketed the northeastern United States for a second day on Wednesday, turning the air a yellowish gray and prompting warnings for people to stay indoors and keep windows closed. Smoke billowed from dozens of fires in several Canadian provinces.
Much of the air was in the “unhealthy or worse categories over areas from the mid-Atlantic to the Northeast and parts of the Upper Great Lakes,” according to an advisory issued Wednesday night by the Environmental Protection Agency.
US authorities issued air quality warnings for many areas and the smoke was expected to linger for days.
Conditions were particularly bad in parts of central New York, where soot in the air was at dangerous levels. In New York City, officials on Wednesday said everyone should stay home. Conditions arrived late Tuesday afternoon, obscuring views of New Jersey across the Hudson River.
Here's a closer look at what's going on and what's in the smoke:
GENESIS OF TOBACCO
The unseasonably hot, dry weather that didn't stop fueled the fires.
“The month of May was just off the charts — record warm across much of Canada,” said Eric James, a modeling expert at the Cooperative Institute for Environmental Science Research at the University of Colorado who is also with the National Oceanic and Atmospheric . Management.
A warming planet will produce hotter and longer heat waves, causing bigger, smokier fires, according to Joel Thornton, professor and chair of the department of atmospheric sciences at the University of Washington.
The fires in the Quebec area are large and relatively close, about 500 to 600 miles (about 800 to 970 kilometers) from Rhode Island, and followed the fires in Nova Scotia.
“I don't remember fires of this scale in the last 10 years,” James said of the fires in Quebec.
Smoke from wildfires in western Canada has been drifting into the United States for weeks. But it's the recent fires in Quebec that have created the dangerous haze on the east coast.
WHY DOES SMOKE GO SO FAR?
Strong winds high in the atmosphere can carry smoke long distances, and it's common for large, violent wildfires to create unhealthy conditions hundreds of miles away from where forests are burning.
But the right combination of circumstances had to line up for the smoke to cover major US cities: A dry, hot spring set the scene. Then the weather did the rest, said Bob Henson, a Yale Climate Change Connections meteorologist.
In Canada, air is circulating counterclockwise around a low pressure system near Nova Scotia. This sends air south over the fires in Quebec. There the air picks up smoke and then turns east over New York state, carrying smoke up the East Coast.
“It's a simple matter of trajectory,” Henson said. “Smoke goes where the wind blows.”
This wind pattern is not particularly rare. But the confluence of events is.
“The timing of these weather patterns unfortunately overlapped with a situation that was ripe for large wildfires,” Thornton said.
Weather patterns are changing and the worst conditions should only last a day or two. Some smoke, however, could linger for a week or more, according to James.
WHAT IS TOBACCO REALLY?
Although smoke looks familiar, it is actually a complex mixture of shapes, from round to corkscrew in the microscope.
“It's not just one type of chemical,” said Rima Habre, an air quality and exposure scientist at the University of Southern California. “It could have gases and carbons and toxic metals.” As it travels, Habre said, it also changes and may contain ozone.
Much of what we see in the air and measure are small particles, or PM 2.5. These are so small that they can get deep into the lungs, where oxygen enters your circulation.
“We're mainly concerned about inflammation in the lungs,” Habre said, from these high levels of pollution. But as climate change fuels wildfires, increasingly, he said, he worries about the greater number of people exposed to less extreme smoke for weeks or months.
“Most healthy adults and children will recover quickly from secondhand smoke exposure and have no long-term health effects,” according to the EPA advisory. But this is less true for a large class of people, including children whose lungs are still developing, older adults and people with lung conditions such as asthma and chronic obstructive pulmonary disease.
Stay inside, keeping your doors, windows and fireplaces closed, is the advice. Air conditioning in a recirculation setting can help filter out some particles, and air filters can remove many others.
