By Janet Raloff
Contractors and building inspectors may soon find themselves dyeing to see asbestos.
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Owing to the mineral’s strength, limited chemical reactivity, and insulating properties, manufacturers have added traces of asbestos over the years to a host of building materials, including those made from concrete. But identifying which materials host the carcinogenic mineral is crucial for detection and cleanup. Doing so has proven problematic because the fibers are both microscopic and colorless.