Smoke from Canadian wildfires bringing ‘unhealthy’ air to US cities: Where is it worst?

(NEXSTAR) – Canadian wildfires are contributing to worsening air quality in dozens of U.S. cities and towns this week, officials say, with states along the northern border currently experiencing the brunt of the pollution.Parts of the upper Midwest and westward toward the Rockies, including Iowa, Montana, North Dakota, South Dakota and Wisconsin, are seeing the worst dips in air quality Monday morning, according to the EPA-affiliated U.S. Air Quality Index (AQI). The unhealthiest air, howe