Dozens of wildfires are burning across Canada[1] in May 2024 and sending unhealthy smoke blowing into the northern U.S. again. At the same time, the southeastern U.S. is getting smoke from Mexico, where drought conditions have been fueling fires[2].
Last year, Canada’s record 2023 wildfire season[3] introduced millions of Americans across the Midwest and northeastern states to the health hazards of wildfire smoke, with air...