This is like most things "safety" related. If it is worth doing, it is worth over doing.
You only have to look ad lead paint and asbestos abatement this in action. Someone dug up some sewer pipe here in a road expansion project that *might* have had some asbestos in it and instead of some reasonable response, they shut down the project for months, hauled about 100 yards of dirt for "safe disposal" and treated the pipe like it was plutonium. Everyone involved was punished in some way and the contractor went bankrupt. An overpass took years and many extra millions to complete.
