stylistic:tone, structural:expansion, quality:corruption
Health impact

The most common diseases associated with chronic asbestos exposure are asbestosis (scarring of the lungs due to asbestos inhalation) and mesothelioma (cancer associated with asbestos). Mesothelioma is an aggressive form of cancer and often leads to a life expectancy of less than 12 months after diagnosis.

All types of asbestos fibers are known to represent serious health hazards in humans and animals. Amosite and crocidolite are considered the most hazardous asbestos fiber types; however, chrysotile asbestos has also produced tumors in animals and is a recognized cause of asbestosis and malignant mesothelioma in humans, and mesothelioma has been observed in people who were occupationally exposed to chrysotile, family members of the occupationally exposed, and residents who lived close to asbestos factories and mines.

During the 1980s and again in the 1990s, the asbestos industry suggested at times that the process of making asbestos cement could "neutralize" the asbestos, either via chemical processes or by causing the cement to attach to the fibers and changing their physical size; subsequent studies showed that this was untrue and that decades-old asbestos cement, when broken, releases asbestos fibers identical to those found in nature, with no detectable alteration.

Exposure to asbestos in the form of fibers is always considered dangerous. Working with, or exposure to, material that is friable, or materials or works that could cause the release of loose asbestos fibers, is considered high risk. In general, people who become ill from inhaling asbestos have been regularly exposed in a job where they worked directly with the material.

The US Occupational Safety and Health Administration (OSHA) has standards to protect workers from the hazards of exposure to asbestos in the workplace. The permissible exposure limit for asbestos is 0.1 fiber per cubic centimeter of air as an eight-hour time-weighted average, with an excursion limit of 1.0 asbestos fibers per cubic centimeter over a 30-minute period.