Not all workers exposed to asbestos will develop diseases from their exposure. In fact, many will experience no ill effects. Asbestos that is bonded into finished products such as walls, tiles, and pipes poses no risk to health as long as it is not damaged or disturbed (for example, by sawing or drilling) in such a way as to release fibers into the air. When asbestos particles are set free and inhaled, however, exposed individuals are at risk of developing an asbestos-related disease. Once these fibers work their way into body tissues, they may stay there indefinitely. The risk of developing asbestos-related diseases varies with the type of industry in which the exposure occurred and with the extent of the exposure. In addition, different types of asbestos fibers may be associated with different health risks. There are many varieties of asbestos, and several studies suggest that certain forms of asbestos are more likely than others to cause lung cancer, asbestosis, and, in particular, mesothelioma. Even so, no fiber type can be considered harmless, and people working with asbestos should always take proper safety precautions.