Live updates: Eastern U.S. air quality reaches harmful levels as Canadian wildfires rage

Smoke and haze from the wildfires ravaging swaths of Canadian forest are smothering the eastern United States. As of mid-afternoon, New York City had the world’s worst air quality, and federal officials briefly halted air traffic at the city’s LaGuardia airport due to reduced visibility. Hazardous particles have degraded air people breathe in places as far away as South Carolina. In New York and other cities, officials warned of health risks and urged vulnerable people to wear high-quality masks — such as a N95 or KN95 — if they go outside. As of Wednesday, Canada was on track to experience its worst wildfire season ever, with officials reporting more than 400 active fires, with more than 240 listed as “out of control.”