Asbestos is a natural fibrous mineral found in soil throughout the world.  Once common as a construction material, it can be very harmful to human beings upon inhalation or digestion.

Asbestos was first used near the beginning of the twentieth century in construction.  Its use soon became widespread, due to its strong, fire-retardant, and good insulating qualities.  It was used in many features of buildings, including flooring, walls, insulation, and more.

Friable, or easily crumbled asbestos, can send nearly microscopic particles into the air.  Upon inhalation, these fibers, which are not easily dislodged once nestled in the lung, can cause any number of adverse effects.  One of these is lung cancer, which has been linked to the inhalation of even a single microscopic asbestos fiber, although risks are undoubtedly higher with greater exposure.  Inhalation can also cause asbestosis, a degenerative lung disease.  Ingestion can result in stomach or gastrointestinal cancers.  In some cases, these diseases do not make themselves apparent for as long as twenty years after asbestos exposure.

OSHA on asbestos

The Asbestos Institute