The list of the world’s most polluted places looks unusually different today.
Instead of cities from South Asia dominating the rankings, including India, dozens of locations across the United States and Canada have surged to the top as smoke from massive Canadian wildfires blankets much of North America, with AQI in over 20 cities crossing 350.
According to the live rankings published by AQI.in at 1:46 pm IST on Friday, July 17, all the world’s top 50 most polluted places were located in the US and Canada, with Ontario cities such as Waterloo, London and Brantford leading the list.
Several American cities across the Midwest and Northeast also featured among the world’s worst-hit locations, including popular destinations like New York City, Chicago and Washington DC.
WHY ARE US AND CANADA SO POLLUTED?
The pollution is not being driven by vehicle emissions or factories but by wildfire smoke.
The cities were shrouded by smoke from more than 850 active wildfires burning across Canada spreading hundreds of kilometres south, reducing visibility and sending dangerous levels of fine particulate pollution, known as PM2.5, into major cities.
As forests burn, they release enormous amounts of PM2.5, that are microscostream.
Meteorologists said a strong high-pressure system, coupled with a heatwave, has trapped the smoke close to the ground instead of allowing it to disperse.
This has led to widespread air quality alerts across more than 20 US states, stretching from Minnesota to New York.
Some cities have recorded extraordinary pollution spikes.
Detroit briefly registered AQI readings above 700 on some monitoring networks, while parts of Michigan’s Upper Peninsula crossed 1,000, levels rarely seen anywhere in the world.
Similar hazardous air quality has been reported across southern Ontario, where authorities have urged residents to remain indoors whenever possible.
The wildfire season has already had a devastating impact in Canada.
More than 850 fires remain active, over 100 of them out of control, forcing tens of thousands of people to evacuate their homes across several provinces, including Manitoba, Saskatchewan and Ontario.
HOW LONG WILL US AND CANADA BE POLLUTED?
Scientists say the poor air quality is likely to persist until a change in weather patterns pushes the smoke away or rainfall helps clear the atmosphere.
Forecasts from Environment and Climate Change Canada (ECCC) and the US National Weather Service (NWS) indicate that shifting winds over the coming days could gradually improve conditions in some areas, although fresh smoke from ongoing wildfires may continue affecting parts of Canada and the northeastern US.
Experts have noted that such widespread smoke events are becoming more frequent as climate change fuels hotter, drier conditions that allow wildfires to grow larger and burn for longer.
Until weather conditions improve or the fires are brought under control, millions across North America could continue breathing unhealthy air, providing a grim glimpse of what the future altered by climate change could look like.
– Ends
