The Iowa DNR has issued an Air Quality Alert for the northernmost four tiers of counties west of I-35 as well as the northernmost tier of counties east of I-35 through 11 pm tomorrow. Smoke from Canadian wildfires has entered the region from the north and fine particulate levels at or above the national standard can be expected. The DNR recommends that people avoid long or intense outdoor activities, and take more breaks during outdoor activities until air quality conditions improve. Members of sensitive groups may wish to take additional precautions. Sensitive groups include people with respiratory or heart disease, children, teenagers, the elderly, and outdoor workers. This alert will expire at 11 pm Tuesday