Preventing injuries may not be the only reason children shouldn’t use off-road vehicles (ORVs).In a new study, public health scientists raise concerns that people who use ORVs in many regions of the country may face exposure to hazardous mineral fibers. These include naturally occurring asbestos and erionite – an asbestos-like material that occurs in sedimentary rocks of the western United States.Most of the deposits are located along the Appalachian Mountains and ranges in the West and Southwest, especially California.