* WHAT...The Minnesota Pollution Control Agency has issued an Air Quality Alert for fine particles pollution. The Air Quality Index (AQI) is expected to reach the Maroon or Hazardous category. * WHERE...Northeast Minnesota. * WHEN...Until 11 AM CDT Friday. * IMPACTS...Everyone is more likely to be affected. * ADDITIONAL DETAILS...Very heavy smoke is expected across the Arrowhead today, as large wildfires continue to spread. Hot temperatures, when combined with the air pollution, will exacerbate health impacts. A frontal boundary will then spread heavy smoke further south this evening into Wednesday morning, as it moves across northern and central Minnesota. The onset of smoke will be rapid. This boundary eventually passes through the Twin Cities and into southeastern Minnesota on Wednesday or Wednesday evening, bringing heavy smoke even further south. Additional rounds of heavy smoke are possible from Thursday through Friday morning across the alert area.