Yahoo TV

Plumes of smoke from wildfires in Canada have traveled south into the United States, bringing darkened skies and a pervasive odor across large swaths of the country. In some cities, including New York, air pollution currently ranks among the worst in the world. The EPA has issued air quality alerts, and many local authorities are warning residents to limit outdoor activities due to health concerns. For those who do venture out, experts are urging the use of masks to limit exposure to pollutants. Smoky conditions are expected to subside but may persist for several days as an estimated 400 wildfires continue to burn in Canada.