The largest US city has regained its leading position after nearly a week of thick wildfire smoke drifting south

New York City has resumed its place atop a list of the world's most polluted cities, beating out runners-up in Vietnam and India with an "unhealthy" rating of 184, IQAir reported on Thursday.

Hundreds of massive wildfires raging across several Canadian provinces have burned for nearly a week, filling the air across the eastern US with a choking orange-brown haze composed of hazardous particulate matter.

New York Governor Kathy Hochul announced the state would give out a million masks free to residents on Thursday, even as she stressed that "this is a temporary situation. This is not Covid." City health officials have advised against exercising outdoors. Wildfire smoke can cause shortness of breath, burning in the eyes, nose, and throat, as well as chest pain. It is believed to be linked to cancer, lung disease and other chronic conditions.

While New York's air remains potentially dangerous, especially for those with asthma and other breathing problems, the situation has improved since Wednesday, when the air quality index (AQI) reached a whopping 405 - the highest level ever seen in the city since the Environmental Protection Agency began keeping records. Flights in and out of the city's La Guardia Airport and nearby Newark Airport were delayed due to lack of visibility.

The irony of this achievement taking place on the Canadian holiday of Clean Air Day was not lost on local media. Due to changing weather patterns, however, the smoke that has blanketed the metropolis for days has begun drifting out toward the Atlantic Ocean.

Nearby Hillsborough, New Jersey fared even worse on Wednesday, topping out at 486 and shattering the state's own record. The AQI only goes up to 500.

New York was also rated the most polluted city on Tuesday, although under normal weather conditions it barely cracks the top 1,000.

Canadian PM Justin Trudeau has described the devastating blaze as "the worst wildfire season we've ever had right across the country." More than 9.4 million acres have burned, amounting to more than 15 times the 10-year average, according to the country's Minister of Emergency Preparedness, while over 125,000 people have been forced to evacuate.

Trailing New York on the most polluted cities list are Hanoi (161), Tel Aviv (156), and Detroit (153).

(RT.com)