The New York mayor has called on city dwellers not to take to the street.
The ongoing forest fires in Canada have recorded the highest air pollution recorded in New York City since 1960.
The EPA reports that Fox News Television has leaked information about the case.
New York Mayor Eric Adams, as well as public health and emergency officials, have warned residents to stay home as long as possible, using protective masks on the street.
The city's health commissioner has said the sharp deterioration in air quality poses a real health risk for citizens, especially the elderly and children.
Federal authorities have suspended the work of New York's Lagardia airport amid a significant deterioration in sight distance in the city.