“It doesn’t include (pollution from) transportation or gas stations. A lot of air pollution comes from those sources.” The state estimates that 40 to 50 percent of volatile organic chemicals in the air come from cars, trucks and buses.

Because of questions by school administrators across the state, the MPCA is sending letters to all superintendents. The letter says the agency is evaluating how the report compares to state monitoring data.

“Our initial analysis indicates that the emissions data used by USA Today may contain errors,” said the letter from Assistant Commissioner David Thornton.

“Minnesota consistently ranks in the top 10 states for air quality,” he wrote.

The MPCA does a lot of air monitoring of toxic chemicals in the Twin Cities area but little or none in most outstate cities.

The USA Today story said children are more at risk when breathing emissions, particularly any heavy metals, because their brains are still developing.

“Reports from polluters themselves often indicated a dozen different chemicals in the air. All are considered toxic by the government, though few have been tested for their specific effects on children,” the article said.

Philip Landrigan, a physician who heads a unit focusing on children’s health and the environment at Mount Sinai School of Medicine in New York, said in the story that the issue should be taken seriously.

“The mere fact that kids are being exposed ought to be enough to force people to pay attention. The problem here is, by and large, there’s no cop on the beat. Nobody’s paying attention.”