Delawareans who step outside on Wednesday may notice a foul smell in the air − a stench similar to that of burning rubber, largely due to pollution caused by Canadian wildfires that has prompted air quality warnings across much of the northeastern United States.
As of about 10 a.m. Wednesday, the air quality index throughout most of Delaware was above 200, which is considered “very unhealthy.” This means the risk of health effects is increased for everyone, not just those who have lung and heart problems or other health conditions.
While air quality improved slightly from early Wednesday morning, Kent County saw the worst air quality, with a rating of 223, according to AirNow, a government-run air quality monitoring website. Greater New Castle County recorded 219, Sussex County recorded 217 and the Wilmington area recorded 207.
The ratings mean that everyone should limit outdoor activity, while sensitive groups − or those with health conditions, pregnant women and those who spend a lot of time outdoors − should avoid all outdoor physical activity.

The poor air quality has prompted some Delaware sports leagues to cancel or postpone games and practices. Just before noon, Delaware Park announced it canceled horse racing scheduled for Wednesday and Thursday.
A news release said the decision was made based upon recommendations by Delaware Thoroughbred Racing Commission veterinarians in conjunction with the Horse Racing Integrity and Safety Authority’s (HISA) air quality guidelines.
Live racing is scheduled to resume Friday.
The haze in. the air hasn’t gone unnoticed online, where residents have taken to social media to report their observations.
Cody Cogar, of Smyrna, who commutes to Newark for work, said he can usually “clearly” see the Wilmington city skyline, Port of Wilmington, Delaware Memorial Bridge, Roth and St. Georges bridges. But on Wednesday, he could “barely see 2-3 miles,” he posted on Reddit.
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On the r/Delaware Reddit page, users have been discussing the unusual smoky skies in the First State. Some warned their friends to be careful.
“What a lovely day to be working the drive thru window with asthma,” one user said.
Others reported feeling adverse effects from the air, with one person saying they sat outside for about 20 minutes and “now I’m coughing a ton.”
“My lungs and eyes hurt and I’ve had to use my inhaler (which I rarely have to),” another person said. “Our school is also having indoor recess due to this. The smell is bad as well.”
Why is there smoke in the air?
Eastern Canada is seeing one of its worst reported wildfires, which is causing much of the poor air. Many people across the eastern United States this week saw a reddish sun in the mornings due to the smoke.
More than 6.7 million Canadian acres have already burned in 2023, federal officials announced last week, marking one of the worst starts to wildfire season. Around 14,000 people were forced to evacuate Quebec with over 150 fires, CBC News reported. Officials said firefighters contained a wildfire in Nova Scotia Sunday but that another one was still burning out of control covering nearly 100 square miles, according to the Associated Press.
While health officials have issued air quality alerts all week, Wednesday morning saw some of the highest numbers yet this week. Central New York recorded some of the worst air, with its AQI rating reaching at least 351, which is considered “hazardous.” News outlets in that state reported that residents’ fire alarms were being triggered by the bad air.
Even Washington, D.C. and Virginia reported poor air quality ratings.
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One of the reasons the air quality is so dangerous has to do with fine particulate matter of 2.5, which is what much of the northeastern U.S. is seeing. These are inhalable particles with diameters that are generally 2.5 micrometers and smaller.
Particulate matter of this size is able to travel deep into the respiratory tract and reach the lungs. Exposure to these fine particles can cause short-term health effects such as eye, nose, throat and lung irritation, coughing, sneezing, runny nose and shortness of breath.
Exposure can also affect lung function and worsen medical conditions such as asthma and heart disease.
Studies suggest that long-term exposure to fine particulate matter “may be associated with increased rates of chronic bronchitis, reduced lung function and increased mortality from lung cancer and heart disease,” according to the New York State Department of Health.
People with breathing and heart problems, children and the elderly may be particularly sensitive to these particles.
How long will smoke last?
The smoke and haze are anticipated to have some improvement as Wednesday morning wears on, but an additional plume of thick smoke should spread south into the area later this afternoon and evening, according to the National Weather Service.
As a result, residents are encouraged to limit their time outside and keep windows and doors closed. Those who planned to be outside should consider moving physical activities indoors or rescheduling them.
Anthony DiMattia contributed to this report.
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