Legislation working its way through the Legislature would weaken some key parts of Minnesota's landmark Next Generation Energy Act, a law that enjoyed broad bipartisan support when it was signed in 2007.

In a nutshell, the law sets renewable-energy goals for Minnesota utilities, with the ultimate objective of getting 25 percent of our electricity from renewable sources by 2025.

According to the state Office of Energy Security, Minnesota's electrical utilities are on track to meet the goals, in spite of the serious economic challenges of the past two years.

Now, some in St. Paul are suggesting that the state turn back to the fuel source that has kept the lights on for more than a century -- coal.

Minnesota already generates roughly 60 percent of its electricity by burning coal, which must be purchased from other states. The state has no coal, oil or natural-gas resources.

This can be seen as a blessing or a curse. Fossil-fuel interests do not wield the political clout here that they have in other states, leaving Minnesota free to become a national leader in clean energy and to pass forward-thinking laws like the Next Generation Energy Act.

While coal's supporters often speak of its lower price tag relative to other fuels, they rarely acknowledge the hidden health costs of burning coal. Burning coal releases at least 84 known hazardous pollutants into the air we breathe, including ozone, particulate matter, nitrogen oxides and sulfur dioxides.

Exposure to those particular air pollutants can result in increased asthma attacks, decreased lung function and inflammation, chronic bronchitis and increased susceptibility to respiratory infections such as influenza.

On March 8, the national American Lung Association issued a report -- "Toxic Air: The Case for Cleaning Up Coal-Fired Power Plants" -- that explains the health risks in great detail.

Hazardous air pollutants from burning coal can travel from 150 to 300 miles in a day, and certain elements can combine to form lung-burning smog. The health risks these pollutants pose are both well-known and well-documented, including:

• Coal-fired power plants produce more hazardous air pollution in the United States than any other industrial pollution sources.

• More than 400 coal-fired power plants in 46 states across the country release in excess of 386,000 tons of hazardous air pollutants into the atmosphere each year.

• Particle pollution from power plants recently has been estimated to kill approximately 13,000 people per year.

Coal has helped to build Minnesota industries, heat its homes and business, and fuel the steam locomotives that connected us with the nation. It served its purpose well, but the state has moved on to the next generation of electricity generation.

Since the landmark federal Clean Air Act was passed 40 years ago, our air quality has improved and our knowledge and ability to find cleaner, more sustainable ways to keep the lights on have grown tenfold.

Minnesota's current laws on new coal-fired power plants are a key step toward a cleaner and healthier future. Stripping them from the Next Generation Energy Act is a very bad idea.

Robert Moffitt is the communications director of the American Lung Association in Minnesota.