Twin Cities get failing grade for particle pollution

A recent air-quality report rated the Twin Cities "F" for particle pollution due to high fine-particle levels in Minnesota. The grade placed the metro at 39th most polluted in the nation for particle pollution, according to the assessment. These particles, often called PM2.5, come from vehicle exhaust, wood burning and industrial emissions and can harm lungs and hearts.

Local coverage framed the finding as a warning about persistent air-quality problems that affect public health across the Twin Cities region. The report is likely to renew discussion about reducing emissions from transportation, heating and industry to lower particle levels and protect vulnerable communities.