The Birmingham metro area has the worst soot pollution of any urban region in the South and it is costing the region billions in economic investment, according to an environmental group study.

The Birmingham region's pollution levels are high enough to put more than 400,000 children and adults at risk for heart and lung disease, according to the a report from the Southern Environmental Law Center.

The report notes the American Lung Association ranks metro Birmingham fifth nationally for soot. It said Jefferson and Shelby counties have lost $5 billion in economic investment and have had to turn down 15 major manufacturing projects due to dirty air.

For two decades, the area has exceeded federal standards for ozone, which causes or worsens breathing disorders like asthma.

SELC offered seven solutions for improving air quality, including cutting soot pollution from heavy-duty diesel engines. It also suggested strictly limiting nitrogen oxides and sulfur dioxide emissions from the three coal-fired power plants, developing a long-term transportation plan to boost mass transit and ensuring that Alabama Power installs and fully utilizes required pollution controls.