Wildfires burning across Washington and Oregon have left Portland with the worst air quality among major cities around the world, edging out Kinshasa in the Democratic Republic of Congo.
The air in both cities is classified as unhealthy, although the quality is improving in the Congolese capital on Wednesday, according to IQ Air, a commercial monitoring service. At the other end of the ranking, Canberra, Oslo and Stockholm have the cleanest air, with Washington DC currently the highest ranked U.S. city.
Air quality alerts have been issued for both sides of the U.S.-Canada border as smoke from wildfires across the Pacific Northwest continues to cloud the skies. That includes parts of Idaho, Montana, Wyoming and Colorado, as well as British Columbia and Alberta. There are also pockets of very unhealthy air around Oregon and Washington…