D.C. issues Code Red air quality due to Canada wildfires

Air quality in Washington, D.C., is worsening as a result of smoke from wildfires in Canada, causing the city to issue a Code Red alert Thursday morning.

“This means very poor air quality is expected, which may be unhealthy for people with heart or lung disease, older adults, children and teens,” the city’s emergency alert system tweeted, an escalation after the city issued a Code Orange on Wednesday.

Dense smoke moved across the Great Lakes and Ohio Valley on Wednesday, increasingly spanning the mid-Atlantic and the Northeast. D.C. was among the cities currently with the worst air quality in the U.S. on Thursday, along with Pittsburgh, Detroit, Cincinnati, Chicago, Philadelphia and Baltimore, The New York Times reported.

Wildfires raging across Canada have posed an issue for much of the continental United States over the past month, with D.C. issuing a Code Purple alert three weeks ago — indicating a slightly more severe air quality index than Code Red.

Wearing a mask may help those with respiratory illnesses, the emergency alert system wrote, and people should consider rescheduling outdoor physical activities or moving them indoors. Choosing less strenuous activities, like walking instead of running, may also be safer.