Report Fuels Debate Over Risk From School Bus Fumes

By Andrew Trotter

A report on the health risks to children from the diesel exhaust from school buses is being received skeptically by school transportation experts.

Nearly 90 percent of the nation's 454,000 school buses have diesel engines, says the study released this month by the Union of Concerned Scientists. The Cambridge, Mass.-based group advocates the adoption of alternatives to the use of fossil fuels.

Drawing on national and state data, the study found that more than one-third of those buses were manufactured before 1991, which means they were built before more-stringent emissions standards were put in place. Such older buses, the report says, can "release at least six times more toxic soot and nearly three times more smog-forming nitrogen...