Asbestos is absolutely cancerous. In fact, around 4% of all lung cancer cases are the result of asbestos exposure. This is why we recommend a full, professional removal and cleaning of any asbestos found in your home. If you are unsure whether there is any present, you should call a pro who will inspect your property.

Asbestos-containing materials are not easily affected by water and do not disintegrate or dissolve when exposed to it. However, porous materials can deteriorate due to water exposure, leading to the release of asbestos fibers into the air. The settling of asbestos fibers can also occur as water makes them heavy, which reduces the risk of airborne exposure, though future disturbance of the materials could cause risk. Wetting asbestos-containing materials does not constitute safe removal, and the proper handling and disposal of asbestos materials should be left to professionals.

No, you do not have to worry about new popcorn ceilings having asbestos. All residential building materials used since the mid-1980s stopped including asbestos, so new popcorn ceilings have no risk of asbestos. You can still create a textured drywall ceiling with a popcorn texture if you like, but new techniques have no risk of adding asbestos. 

Vermiculite insulation that comes from a particular mine before 1990 is likely to contain asbestos. This is particularly true in the U.S. However, not all types of vermiculite insulation contain asbestos. Since you can't detect the presence of asbestos without special equipment, it's best to assume that the insulation contains the dangerous mineral and to either leave it alone or hire a professional to handle it.