New York air quality has suddenly become worse than New Delhi's; here's why

New York City on Wednesday had the highest levels of air pollution among significant cities worldwide, surpassing even New Delhi, as smoke from the Canadian wildfires poured into the US East Coast and Midwest. The situation was such that the picturesque and renowned skyline of New York City became invisible behind a hazy veil of smoke from the Canadian wildfires flowing into the region.

"It's critical that Americans experiencing dangerous air pollution, especially those with health conditions, listen to local authorities to protect themselves and their families," US President Joe Biden tweeted, responding to the situation. He added that more than 600 US firefighters, support personnel, and equipment have been deployed to support Canada as they respond to record wildfires.

According to IQAir, New York City had the highest levels of air pollution among significant cities worldwide on Wednesday morning, surpassing even New Delhi. The AQI reached 173 US AQI at 11:30 am, considered unhealthy for everyone. Meanwhile, the US AQI stood at 164 for New Delhi at the same time.

As a result, a ground stop was issued at Newark Liberty International Airport in New Jersey and LaGuardia Airport in New York City on Wednesday afternoon due to low visibility from the smoke and haze, according to the Federal Aviation Administration.

In addition to New York, strong smell of smoke, dark skies and breathlessness caught the attention of residents in other cities and towns from Maryland to New Hampshire, reporting low visibility and hazy skies.

Some of the worst air quality levels were found in Delaware. Wilmington, Delaware, which is located about 24 miles southwest of Philadelphia, saw air quality index of 199, which is considered very unhealthy.

Due to the reduced visibility from wildfire smoke, some flights into the New York City area and Philadelphia were delayed on Wednesday and others were briefly halted. Schools across the US East Coast also cancelled outdoor activities in view of the situation.

Here's what's happening

Vast swathes of the northern United States are covered in a thick layer of smoke with air alerts being triggered in several cities as wildfires rage in Canada. AccuWeather forecasters say the wildfire season in Canada got off to a devastatingly early start.

As of early June, more than 8 million acres of land have been scorched by wildfires across Canada, according to the Canadian Interagency Forest Fire Centre (CIFFC). The CIFFC was tracking more than 400 active fires across the nation Monday.

This alert means air pollution concentration in the region will be unhealthy for people with heart or lung disease, children, and adults over 65. The alert warned these people to limit their time outdoors.

"Exposure to elevated levels of fine particles such as wood smoke can increase the likelihood of respiratory symptoms in sensitive individuals and aggravate heart or lung disease," the National Weather Service alert said.

AccuWeather forecasters expect "very unhealthy" levels to continue through the rest of the week.

(With inputs from PTI)