Millions breathing hazardous air as smoke from Canadian wildfires streams south over US

Smoke from Canadian wildfires poured into the US East Coast and Midwest on Wednesday, covering the capitals of both nations in an unhealthy haze, holding up flights at major airports, postponing Major League Baseball games and prompting people to fish out pandemic-era face masks.

Canadian officials asked other countries for additional help fighting more than 400 blazes nationwide that already have displaced 20,000 people. 

Air with hazardous levels of pollution extended into the New York metropolitan area, central New York state and parts of Pennsylvania and New Jersey. 

Massive tongues of unhealthy air extended as far as North Carolina and Indiana, affecting millions of people.

The air quality index, a US Environmental Protection Agency metric for air pollution, exceeded a staggering 400 at times in Syracuse, New York City and Pennsylvania's Lehigh Valley.

A level of 50 or under is considered good; anything over 300 is considered hazardous, when even healthy people are advised to curtail outdoor physical activity

Canadian officials say this is shaping up to be the nation's worst wildfire season ever. It started early on drier-than-usual ground and accelerated very quickly, exhausting firefighting resources across the country, fire and environmental officials said.

Smoke from the blazes in various parts of the country has been lapping into the US since last month but intensified with recent fires in Quebec, where about 100 were considered out of control Wednesday which, unsettlingly, was national Clean Air Day in Canada.

The smoke was so thick in downtown Ottawa, Canada's capital, that office towers just across the Ottawa River were barely visible.

In Washington, White House press secretary Karine Jean-Pierre said President Joe Biden has sent more than 600 firefighters and equipment to Canada. His administration has contacted some US governors and local officials about providing assistance, she said.

The largest town in Northern Quebec Chibougamau, population about 7,500 was evacuated Tuesday, and Legault said the roughly 4,000 residents of the northern Cree town of Mistissini would likely have to leave Wednesday. But later in the day, Mistissini Chief Michael Petawabano said his community remains safe and asked residents to wait for instructions from Cree officials.

Eastern Quebec got some rain Wednesday, but Montreal-based Environment Canada meteorologist Simon Legault said no significant rain is expected for days in the remote areas of central Quebec where the wildfires are more intense.

The Federal Aviation Administration paused some flights bound for LaGuardia Airport and slowed planes to Newark Liberty and Philadelphia because the smoke was limiting visibility.

It also contributed to delayed arrivals at Dulles International Airport outside Washington, where a heavy haze shrouded the Washington Monument and forced the cancellation of outdoor tours.

Major League Baseball put off games in New York and Philadelphia, and even an indoor WNBA game in Brooklyn was called off. 

Schools in multiple states cancelled sports and other outdoor activities, shifting recess inside. 

Live horse racing was canceled Wednesday and Thursday at Delaware Park in Wilmington. Organizers of Global Running Day, a virtual 5K, advised participants to adjust their plans according to air quality.

New Jersey closed state offices early, and some political demonstrations in spots from Manhattan to Harrisburg, Pennsylvania, were moved indoors or postponed. Striking Hollywood writers were pulled off picket lines in the New York metropolitan area.ns, not just herself.