Asbestos, which was supposedly named by ancient Greek alchemists, is a mineral derived from silicon that forms six types of fibers, all of which are capable of causing serious health effects in human beings. Asbestos has proven useful to many previous cultures and peoples due to its protective and insulating properties, but it wasn't until the 1970s that governments recognized its hazards to human health and began limiting its use. Exposure to asbestos is predominantly through inhalation, which is why most potential health effects are related to the lungs.
Malignant Lung Cancers
Once inhaled, asbestos fibers become stuck within tissues of the trachea, bronchi, bronchioles, alveoli and pleural membranes, which is where they can induce different types of cancer. According to the National Cancer Institute, asbestos is a recognized carcinogen by many human health agencies, and exposure by inhalation dramatically increases the risk of malignant lung cancers. Most malignant lung cancer is of the small-cell type, and develops in the bronchi before it spreads throughout the body in the blood and lymph.
Cigarette smoking is a big factor in increasing the risks of asbestos induced lung cancer. Asbestos.com notes that the relative risk of dying from malignant lung cancer is 87 percent if a person works with asbestos and smokes more than a pack per day. For comparison, the relative risk for heavy smokers not exposed to asbestos drops to 11 percent chance of mortality, and then 5 percent for nonsmoking asbestos workers.
Benign Lung Tumors
A benign tumor is a collection of cancer cells that are encapsulated, which prevents them from metastasizing around the body. Benign lung tumors can manifest anywhere in the respiratory system from asbestos exposure. The tumors can be fibrous and calcify, which makes them identifiable on X-rays, and they are often accompanied by pleural thickening and effusions, according to the National Cancer Institute.
Malignant Mesothelioma
Malignant mesothelioma is life threatening, albeit slow growing, cancer of the mesothelium, which are the thin membranes that cover the inside of the chest and abdominal cavities. Mesothelioma is the most common cancerous process linked with asbestos exposure, according to MayoClinic.com. Mesothelioma is caused almost entirely by inhaling asbestos fibers, which frequently induce malignant cancer in the pleural linings. Mesothelioma may be asymptomatic for many years before it becomes debilitating and life threatening.
Other Potential Cancers
The National Cancer Institute reports that the risks of other types of cancers may be elevated with asbestos exposure. These include gastrointestinal, colorectal, throat, kidney and gallbladder cancers.
Lung Asbestosis
Asbestosis is an incurable, inflammatory lung condition caused by inhaling asbestos fibers. Asbestosis is considered a type of pulmonary fibrosis that scars the lung tissues and makes them less able to expand and exchange oxygen for carbon dioxide, as noted by the National Health Service. Asbestosis takes many years to develop and become debilitating, and it often is a precursor for malignant lung cancers and mesotheliomas.
