Today, asbestos is still used in gaskets, brakes, roofing and other materials. The mere presence of asbestos materials in a home is usually not a serious problem or hazard. The danger is that asbestos materials may be disturbed or crumble over time, causing the fibers to be released into the air. Asbestos materials that crumble easily if handled, or that have been sawed, scraped or sanded into a power pose the greatest danger. The risk of these cancers increases with the number of asbestos fibers inhaled.
Smokers are even more at risk when inhaling asbestos fibers.
Symptoms of the diseases do not usually appear until 20 to 30 years after the first exposure of the inhaled asbestos fibers. Most people who get asbestosis have usually been exposed to high levels of asbestos fibers for a long time. However, there is no known safe exposure to asbestosis. According to the Environmental Protection Agency, the best thing to do with asbestos materials in good condition is to leave them alone. Disturbing them may create a health hazard where none existed.