Millions of Americans face air quality alerts from Minnesota to New York as authorities urge people to stay indoorsSign up for the Breaking News US newsletter emailTell us: have you been affected by the spread of wildfire smoke in the US and Canada?Smoke from wildfires burning in south-central Canad a and parts of Minnesota is spreading across the US, prompting air quality alerts in more than 20 states with millions of Americans expected to face unhealthy air conditions this week.The smoke from the more than 180 active wildfires in northern Ontario made Chicago’s air quality the worst in the world on Thursday evening, followed by Detroit and Minneapolis, according to IQAir’s global rankings. Continue reading... ...read more read less