US President Donald Trump has unleashed a furious attack on Canada as dense wildfire smoke billowing south across the border triggered dangerous air quality alerts across the United States, casting a shadow over the World Cup final outside New York this weekend.<\/p>\n
\u201cThe United States is being unnecessarily invaded by filthy, polluted, and unhealthy air, the quality of which is dangerous, and totally unacceptable!\u201d Trump wrote on Truth Social Saturday morning Sydney time.<\/p>\n
It comes as stunning satellite images show a river of smoke pouring across the Midwest and Northeast of the United States. <\/p>\n
Mr Trump said he would personally call Canadian Prime Minister Mark Carney \u201cto find out what they are going to do about\u201d the smoke, as more than 200 fires burned out of control across Canada on Friday \u2014 with the situation worsening by the hour, particularly in Ontario.<\/p>\n
Detroit remained the most polluted city in the world on Friday, according to air quality tracker IQAir, with parts of Michigan, Minnesota and Wisconsin recording readings deep into the \u201chazardous\u201d range for days. Washington and Chicago were not far behind, and officials across the affected cities warned residents against spending unnecessary time outdoors.<\/p>\n
In New York and neighbouring New Jersey, where the World Cup football final is scheduled to be played on Sunday in an open stadium, the metropolitan area was experiencing air quality classified as unhealthy for sensitive groups \u2014 an improvement on Thursday, when smog had rendered the Manhattan skyline barely visible. But the National Weather Service warned the smoke could thicken overnight into Saturday morning, leaving the situation far from resolved.<\/p>\n
Tournament organisers said they were \u201cmonitoring closely,\u201d with White House World Cup task force executive director Andrew Giuliani briefing reporters on the developing conditions.<\/p>\n
NWS meteorologist Peter Mullinax said winds sweeping across the Great Lakes had the potential to push further smoke into the Northeast, keeping skies hazy through the weekend.<\/p>\n
\u201cI don\u2019t believe that this should be as impressive, inspirational as if you might be playing a game today,\u201d Mullinax told AFP.<\/p>\n
For Sunday\u2019s final, the critical question remains whether additional smoke pushes south following weekend storm systems. Joel Dreessen, an air quality forecaster for the state of Maryland, said conditions were being watched carefully.<\/p>\n
\u201cSome of the models are starting to indicate that we\u2019ll start to pull down some smoke,\u201d he said.<\/p>\n
Across affected cities, residents took no chances, with people donning masks outdoors to filter out the hazardous particles. In New York, libraries and train stations distributed masks free of charge to commuters and pedestrians.<\/p>\n
Health experts warned the danger should not be underestimated. Chris Carlsten, who studies the health impacts of fire smoke at the University of British Columbia, said fine particles produced by wildfires posed particular risks to the lungs, differing from vehicle pollution, which tends to skew towards cardiovascular impacts.<\/p>\n
Carlsten said smoke plumes carry not only wood and vegetation debris, but also paint, plastic and metal particulates. Critically, he warned that as smoke travels over vast distances, it undergoes what scientists call \u201cphotochemical ageing\u201d \u2014 a chemical transformation that makes it increasingly dangerous.<\/p>\n
\u201cSeem to make, from everything we understand in the chemistry, the aerosol more toxic,\u201d Mr Carlsten said of the reactions.<\/p>\n
The fires driving the crisis showed little sign of easing. In Canada, blazes were intensifying on Friday, with Ontario bearing the brunt of the emergency. While no casualties have been reported in Ontario, several remote communities have been evacuated, with dozens of aircraft deployed to battle the advancing fires.<\/p>\n
Across the border in the United States, 16 active fires were burning in the Superior National Forest along Minnesota\u2019s boundary with Canada.<\/p>\n
The US Forest Service painted a grim picture for firefighting crews on the ground.<\/p>\n
\u201cThe forecast for erratic weather, shifting winds and the potential for isolated damaging wind gusts and thunderstorms will be a challenge for firefighting efforts,\u201d it said in a statement.<\/p>\n
Scientists and climate advocates stressed the broader forces at play. Mark Parrington, a scientist at the Copernicus Atmosphere Monitoring Service, said climate change was creating the conditions for longer, more destructive fire seasons through higher surface air temperatures and lower soil moisture.<\/p>\n
\u201cWhen there\u2019s an ignition, we see these really large-scale, persistent burning where these fires can burn for weeks and weeks at a time through summer,\u201d Mr Parrington said.<\/p>\n