US midwest braces for smoky skies as Canadian wildfires rage on

Air quality alerts issued in Minnesota and Wisconsin with winds expected to blow airborne pollution from Ontario blazes south

The smoke-filled skies seen across US cities last week are set to make another appearance, as Canadian wildfires rage on and winds are bringing the airborne pollution south and again triggered fears over risks to health.

Air quality alerts were issued on Wednesday for the entire state of Minnesota and large parts of Wisconsin. This time, the culprit is a series of wildfires from the Canadian province of Ontario.