"Dry conditions and record-high temperatures have fueled wildfires blanketing the Pacific Northwest in smoke."
"Seattle, Washington, and Portland, Oregon, were the two major cities with the worst air quality in the world Thursday due to wildfires burning in the Pacific Northwest.
Seattle was ranked No. 1 while Portland was No. 2 on a list of rankings compiled by IQAir, a Swiss air quality technology company. IQAir collects data from individual monitoring stations in cities around the world. Thursday was the second day in a row that Seattle had the top spot.
Beijing was in third place. The Chinese capital has historically been plagued by air pollution, though it met state air quality standards for the first time last year. After Beijing, the city with the fourth worst air pollution was the Canadian city of Vancouver, British Columbia, about 140 miles north of Seattle.
“At this point in the year, it’s unprecedented to see influences from wildfire smoke the way we have been seeing it in the last week or two,” Donna Haga, senior air quality meteorologist with the B.C. Environment Ministry, told the Vancouver Sun."