For asbestos they are microscopic glass toothpicks that penetrate to the smallest reaches of the lung and get stuck. They are not cleared and will form a unique type of lung cancer. Theoretical cancer models, one hit hypothesis, is what your hearing about. Its theory. The suggestions to encapsulate are good ones. The approach to not disturb/sand etc. is also the best way to reduce an exposure risk. Wear PPE and you’ll be fine. Note the asbestosis lawyer commercials, they were occupational exposures without PPE.