Asbestos is a silicon fiber that exists in six slightly different forms. The properties of asbestos include heat, fire, electrical and chemical resistance, as well as high tensile strength. Asbestos was used by various ancient peoples, but it was not until the beginning of the 20th century that asbestos became common in building and manufacturing products, and its causality in human diseases became apparent. Asbestos exposure almost always occurs through inhalation of fibers, which become deposited in the throat, lungs and surrounding tissues, leading to a variety of diseases.
Cancers of the Lung
The National Cancer Institute states that asbestos has been classified as a human carcinogen by the U.S. Department of Health and Human Services, the Environmental Protection Agency and the International Agency for Research on Cancer. Specifically, asbestos exposure increases the risk of malignant lung cancer and benign tumors. Lung cancers caused by asbestos often begin growing in the bronchial tubes, although other sites, such as the trachea, bronchioles and alveoli, are also implicated. Malignant, small-cell lung cancer caused from asbestos has very high mortality rates. According to the Agency for Toxic Substances and Disease Registry, the risks of developing lung cancer from asbestos exposure are many times greater when cigarette smoking is involved. Specifically, asbestos worker's risks of lung cancer are up to 84 times greater if they smoke. The toxic chemicals and tars in cigarettes seem to accelerate the pathogenic effects of asbestos in the lungs.
Mesothelioma of the Chest
Mesothelioma is cancer of the thin layer of tissue lining the body's internal organs, known as mesothelium, and is the most common type of cancer associated with asbestos, as cited on Mesothelioma.com. In fact, asbestos exposure is the single known cause of mesothelioma, of which there are three forms. The most common form is pleural mesothelioma, which occurs about 70 percent of the time and the type most likely to become malignant.
Mesothelioma may take many years to develop, even with daily exposure, and the early stages often produce no symptoms. However, in advanced stages, mesothelioma can cause back pain, chest pain and tightness, shortness of breath, coughing with blood, difficulty with swallowing, fevers and night sweats, and even physical lumps on the front of the torso from the tumors.
Asbestosis
Breathing in sharp asbestos fibers does not always lead to cancer or mesothelioma, but it always causes lung damage and scarring such as asbestosis. Specifically, asbestosis is an inflammatory reaction by the lung tissue to the asbestos fibers. The lung tissue undergoes fibrosis and becomes unable to expand and exchange gases normally, according to MedlinePlus. Symptoms of asbestosis parallel those of mesothelioma, although permanent lung scarring is always involved.
Other Lung Diseases
MedlinePlus notes that other lung and pleural diseases can occur from asbestos exposure, such as pleural membrane plaques or calcification, pleural thickening and pleural effusions, which contain fluid from edema.
Other Potential Cancers
The National Cancer Institute notes that other forms of cancer might be induced by moderate to heavy exposure to asbestos, and they include gastrointestinal and colorectal cancers, and potentially cancers of the throat, kidneys, esophagus and gallbladder.
