WASHINGTON: Residents of the northeastern United States were breathing more easily Friday (Jun 10) as smoke from Canadian fires gradually cleared after blanketing several cities in a noxious haze this week.
In New York and Washington, air quality was classified as "moderate" by the US Environmental Protection Agency.
In the American capital, the sky was blue again Friday morning, but as a measure of precaution, children at city public schools were still prohibited from spending recess outdoors.
In New York, public schools were closed and operated remotely.
Air quality improved after winds blowing over the Canadian province of Quebec, where the fires are raging, changed direction, Ryan Stauffer, a NASA scientist specialising in air pollution, told AFP.
The concentration of fine particles in the air was up to twenty times lower Friday morning in Washington, compared to the same time on Thursday, Stauffer said.
Thick skies and an acrid smell hung over the region for days, with air pollution exceeding some of the most contaminated cities in the world in South Asia and China.
Flights were delayed at many airports due to reduced visibility, and masks reappeared on the streets.