In the production of different products there are several different types of asbestos forms possible, not all which are harmful. The single most problematic type of asbestos form is the airborne variety, which leads to direct inhalation of the fibers that then act within the lungs and body to create different health symptoms and cancers. In its natural state asbestos is a mineral that is found in rock formations that are typically in the earth and are mined through open types of pit mines. In a solid form the asbestos is not harmful to people, it is only when inhaled or ingested that it becomes the very significant carcinogen. The problem with the airborne asbestos form is that it is microscopic and shaped like a needle, easily passing through the natural filters in the nose and entering directly into the lungs. The shards then lodge in the lungs, preventing the mucous from cleaning out the irritant as would occur with other inhaled microscopic particles. This health risk with airborne asbestos form is well known and was documented as early as 1930 in the United Kingdom.