asbestos

Asbestos refers to a group of naturally occurring silicate minerals that form long, flexible fibers. The most common varieties are chrysotile (white asbestos) and the amphiboles amosite (brown asbestos) and crocidolite (blue asbestos), along with tremolite, actinolite, and anthophyllite. The fibers are valued for resistance to heat, fire, and chemicals, properties that historically led to widespread use in insulation, roofing, cement products, brake linings, gaskets, and other construction materials.

Health effects: Inhalation of airborne asbestos fibers can cause serious, sometimes fatal diseases. After long latency, exposure is linked to asbestosis (scarring of lung tissue), pleural disease, mesothelioma (a cancer of the lining of the lungs or abdomen), and various lung cancers. The risk increases with the amount and duration of exposure and smoking. There is no known safe level of exposure.

Regulation and legacy: Many countries have banned or restricted asbestos use; however, legacy materials remain in older buildings and infrastructure. Chrysotile was used most widely, while amphibole forms are considered more hazardous due to greater persistence in the lungs. Safe handling requires trained personnel and containment during removal.

Diagnosis and management: Diseases are diagnosed by imaging and tissue biopsy. Treatments may include surgery, chemotherapy, radiation, and, in some cases, immunotherapy, but mesothelioma carries a poor prognosis. Prevention focuses on preventing exposure and proper abatement of asbestos-containing materials.