Associated Press

MARION: School officials have restricted access to a second site at the River Valley high- and middle-school campus after anothercancer-causing chemical was detected.

The petroleum-based chemical benzopyrene -- found in asphalt, tar and cigarette smoke -- registered nearly two times higher than acceptable standards in a soil sample taken just outside a back door to the middle school.

Superintendent Thomas Shade ordered two middle-school back doors labeled as emergency exits Friday and told teachers and students not to use them.

Shade consulted with Ohio State University toxicologist Deborah Gray, who despite finding no immediate health threat, advised limiting access to the site, which is about 35 miles southwest of Mansfield.

Neither the Ohio Environmental Protection Agency nor the Army Corps of Engineers thought such action was warranted.

``Exposure may not be any different than congregating around a parking lot, especially if it was a freshly paved parking lot,'' said Jeff Steers, assistant chief of the EPA's Bowling Green office. ``But if the school wants to go above and beyond . . . they can extra err on the side of caution.''

For more than two years, the campus has been the focus of an environmental investigation after health officials confirmed that an unusually high number of graduates developed leukemia.

Investigators found a highly contaminated former Army dump on six acres of the campus used mostly for athletic events. Access has been restricted to that area since February 1998 after trichloroethylene, a solvent linked to leukemia, was detected in the soil in the dump.