Every now and then a document crosses your desk that makes you sit up straight. Studies that quantify the economic cost of pollution to kids' health recently caught my eye.

A national study released in 2002 estimated that the annual price to the U.S. economy of children's health problems resulting from pollution was $54.9 billion. A more recent study published in 2009 found that more than 850,000 children may be at risk of respiratory disease from living in proximity to traffic in the U.S., at a cost of hundreds of millions of dollars.

Our state is not immune. A study released by two Minnesota organizations, the Institute for Agriculture and Trade Policy and the Minnesota Center for Environmental Advocacy in 2006 estimated that pollution was linked to an estimated $1.5 billion each year in costs related to childhood disease. The report estimated childhood asthma cost the state $30.6 million per year, cancer $8.2 million per year, lead poisoning $1.2 billion per year, birth defects $4.5 million per year and neurobehavioral disorders $303 million per year.

The good news is that thanks to environmental and health rules, many childhood diseases and other health effects related to pollution have declined since the 1970s. And Minnesota has taken aggressive action in controlling health threats to children, everything from mercury in coal and fish to toxins in baby bottles. But the high costs of pollution to kids — not just in dollars, but in happiness and security — mean we should do more.