Toxic wildfire smoke has engulfed much of the northern US, bringing with it an unsettling odor that many say smells more like burning plastic than a campfire.
Millions of Americans remain under air quality warnings as smoke from hundreds of Canadian wildfires blankets the Great Lakes, Upper Midwest and Northeast, pushing pollution levels into the EPA’s most severe ‘hazardous’ category across parts of the region.
Many people beneath the smoke plume have reported a burning plastic smell in the air, which atmospheric scientist Matthew Cappucci said is caused by longer-lasting compounds, including benzene and formaldehyde, that remain after the smoke has aged during its journey.
Both benzene and formaldehyde are classified as Group 1 human carcinogens, meaning there is sufficient evidence that they can cause cancer in humans.
‘The smoke isn’t just annoying – it’s legitimately dangerous. It’s made up of microscopic particulates known as PM2.5, or itty-bitty particles less than 2.5 micrometers in width. That’s about 30 times thinner than a human hair,’ Cappucci shared on X.
‘Breathing them in is bad – it increases [the] risk of heart attack, respiratory issues, etc. You may also notice your eyes stinging.’
The smoke has become so intense that major metropolitan areas, including Chicago, Detroit, Washington DC and New York City, ranked among the world’s most polluted cities on Friday.
According to the FOX Forecast Center, Michigan has been hit hardest by the smoke so far, with the entire state experiencing its worst air quality since modern records began in the early 2000s.Â
Weather experts have said the intense smoke will create vivid sunrises and sunsets this week, like one seen in New York Friday morning
Pictured: The New York City skyline shrouded in wildfire smoke on July 17
The wildfire smoke pouring down from hundreds of forest fires in Canada, mainly in the province of Ontario, is filled with microscopic pollutants called fine particulate matter, or PM2.5.
These are toxic compounds typically created by burning wood or industrial pollution, which are small enough to penetrate human tissue and cause severe breathing issues or even death among people with heart and lung disease.
Health officials have noted that breathing in PM2.5 in the amounts currently seen in Detroit on Friday equates to smoking more than 13 cigarettes in a single day.
On Friday, President Donald Trump vowed to hold Canada responsible for the plume of toxic wildfire blowing into the US.Â
‘We are holding Canada responsible for the fact that they are not properly maintaining their Forests, and Brush therein, and the United States is being unnecessarily invaded by filthy, polluted, and unhealthy air, the quality of which is dangerous, and totally unacceptable!’ reads a post from the president on Truth Social.
‘This is Willful Negligence, and becoming a yearly occurrence, costing the United States Billions of Dollars, which cost of this pollution must of necessity be added to the TARIFFS Canada is currently paying.’
According to the live air quality-tracking website IQAir, breathing in Chicago’s air is the equivalent of smoking more than 10 cigarettes in a day.
According to Berkeley Earth, a nonprofit research organization that analyzes climate and air quality data, spending a full day breathing moderately elevated levels of PM2.5 pollution has roughly the same long-term health impact as smoking one cigarette.Â
Dr Jonathan Tan from the Children’s Hospital of Philadelphia told AccuWeather: ‘When the AQI climbs into the 150+ range for a full day outside, that’s in the ballpark of [smoking] seven to nine cigarettes.’
Typically, the Air Quality Index (AQI) is measured on a scale from 0 to 500: ‘good’ (0–50) carries little risk, ‘moderate’ (51–100) may affect sensitive individuals, ‘unhealthy for sensitive groups’ (101–150) poses increased risk and ‘unhealthy’ (151–200) impacts everyone, limiting outdoor activity.
When outdoor air quality reaches the 300 to 500 ‘hazardous’ zone or surpasses that mark, the EPA warns that everyone should avoid all physical activity outside. As of 9am ET on Friday, both Detroit and Chicago had surpassed 380, according to IQAir.
Washington DC registered at 247, the third-worst polluted major city on the planet, and New York was fourth at 165 – all in the unhealthy to very unhealthy ranges.
The growing plume of pollution-filled smoke has been blamed on Canada’s lack of fire management services, which has now allowed roughly 800 wildfires to burn through over two million acres of land throughout the country this year.
Dan DePodwin, AccuWeather’s vice president of forecasting, told the Daily Mail: ‘Because a lot of Canada is very rural, in many parts of the country, they don’t actively fight fires, because there is very little to no population nearby.’
Pictured: Runners in Washington DC attempt to exercise despite heavy smoke from the Canadian wildfires reaching the Mid-Atlantic, including in Maryland and Virginia
Pictured: Pedestrians in Chicago were forced to wear face masks as the air quality reached ‘hazardous’ levels throughout the city on July 17
On Thursday, Chicago (Pictured) was covered in wildfire smoke pouring south from Canada
Pictured: A cyclist travels through the wildfire smoke in Washington DC on July 17
‘So, the fires burn until they go out themselves, or they do minimal fire suppression. So that is part of it, that is occurring here,’ he continued.
The situation has drawn the ire of US lawmakers, who slammed the Canadian government’s alleged inability to contain the wildfires and the smoke reaching the northern US.
Congressman Nick Langworthy of New York said: ‘Americans should not be forced to breathe hazardous air year after year because Canada refuses to properly manage its forests.’
‘This is no longer a one-time emergency – it’s becoming an annual public health crisis. That is unacceptable,’ added Langworthy, who represents parts of Buffalo, which has been severely impacted by the toxic air crisis.
Congressman Bill Huizenga of Michigan also called on the Canadian government to work with the US on finding a solution to the annual wildfire problem north of the border.
‘Michiganders must stop paying the price for bad policy,’ Huizenga declared.
Satellite images show a massive plume of wildfire smoke blanketing mulitple US states on Friday
Air quality readings in Chicago on Friday, July 17 revealed ‘very unhealthy’ to ‘hazardous’ air throughout the entire city
Pictured: A woman in New York wears a face mask as the air quality remained in the unhealthy zone on July 17
Residents in New York (Pictured) struggled to breathe outdoors on Thursday due to intense air pollution from the Canadian wildfires
The city of Detroit, Michigan (Pictured) has been ranked as the most polluted city on Earth due to the Canadian wildfire smoke
NWS officials also urged anyone considered to be in a ‘sensitive group’ to avoid poor air quality and remain indoors with the windows shut on Friday.
These groups include the elderly, young children, pregnant women and those with chronic health problems such as heart and lung disease.
‘If you don’t have an air conditioner, staying inside with the windows closed may be dangerous in extremely hot weather. If you are hot, go someplace with air conditioning or check with your local government to find out if cooling centers are available in your community,’ the agency recommended.
‘Make sure to keep pets indoors to limit their exposure to poor air quality,’ the AccuWeather team added in a statement.
