One third of American public schools are in an “air pollution danger zone,” researchers at the University of Cincinnati found in a new study to be published in the Journal of Environmental Planning and Management. They defined danger zones as areas within a quarter-mile of heavily trafficked highways. Diesel particles and other pollutants from highways can heighten kids’ risk for asthma and respiratory problems later in life. “This is a major public health concern that should be given serious consideration in future urban development, transportation planning, and environmental policies,” said lead investigator and UC enviro health prof Sergey Grinshpun. Past research in this area has focused on where kids live, not taking into account the fact that they spend a third of their day at school. Grinshpun says schools need to be built further from highways, and those currently in danger zones should get good air-filtration systems. California, always on the ball, has already passed a law forbidding the construction of schools within 500 feet of busy roads.