Smoke from Canadian wildfires is causing air quality concerns for millions of Americans in the Midwest and Northeast. Air quality alerts were in effect Tuesday in several states, including Wisconsin,

Almost 200 wildfires are burning out of control in Canada, including 81 in Saskatchewan, 159 in Manitoba and 61 in Ontario. Figures from the Canadian Interagency Forest Fire Center indicate that more than 16.5 million acres have been scorched so far this year in what will likely be the country’s second-worst wildfire season on record.