Air pollution in New York City among the worst in the world on Tuesday night

Later in the night, the city experienced the second-worst levels of air pollution in the world following New Delhi in India, CNN reported, citing IQair. Other cities on the list included Qatar, Doham Iraq, Baghdad and Lahore.

New York City had also topped the list briefly on Tuesday morning, resulting in around 10 school districts in the central part of the state cancelling outdoor events and activities for the day.

Wildfire smoke comprises PM2.5, the tiniest pollutant known so far, and yet the most dangerous. When inhaled, it can get deep into a person's lung tissue and also enter their bloodstream. It is also generated from sources such as combustion of fossile fules, wildfires, dust storms and has been liked to quite a few health problems such as heart disease, asthma and respiratory illness.

On Tuesday, the PM2.5 concentration in New York City's air was over 10 times the WHO guidelines, CNN reported.

According to Canadian Interagency Forest Fire Center, there are over 150 active wildfires burning in Quebec this week, this is over the double fires burning in any other province in the country, CNN reported.

Quebec has witnessed over 400 wildfires in 2023, so far, CNN reported.