Asbestos Health Hazards :

Asbestos Health Hazards

Hazard Summary:

Asbestos has been used in building materials, paper products, plastics, and other products. Exposure mainly occurs in indoor air where it may be released from these materials. Effects on the lung are a major health concern from asbestos, as chronic (long-term) exposure to asbestos in humans via inhalation can result in a lung disease termed asbestosis.

Asbestosis is characterized by shortness of breath and cough and may lead to severe impairment of respiratory function. Cancer is also a major concern from asbestos exposure, as inhalation exposure can cause lung cancer and mesothelioma (a rare cancer of the thin membranes lining the abdominal cavity and surrounding internal organs), and possibly gastrointestinal cancers in humans. EPA has classified asbestos as a Group A, known human carcinogen.

Asbestos Uses

• The main uses of asbestos are in building materials, paper products, asbestos-cement products, friction products, textiles, packings and gaskets, and asbestos-reinforced plastics. (1)
• Asbestos use in the United States is currently decreasing. (1)
Sources and Potential Exposure
• Airborne exposure to asbestos may occur through the erosion of natural deposits in asbestos-bearing rocks, from a variety of asbestos-related industries, or from clutches and brakes on cars and trucks. The concentrations in outdoor air are highly variable. (1)
• Asbestos has been detected in indoor air, where it is released from a variety of building materials such as insulation and ceiling and floor tiles. It is only released, however, when these building materials are damaged or disintegrate. Typical concentrations in indoor air range from 1 to 200 nanograms per cubic meter (ng/m3) (0.000001 to 0.002 milligrams per cubic meter (mg/m3)). (1)
• Asbestos may be released to water from a number of sources, including erosion of natural deposits, corrosion from asbestos-cement pipes, and disintegration of asbestos roofing materials with subsequent transport into sewers. (1)
Assessing Personal Exposure
• It is possible to test for the presence of asbestos fibers in urine, feces, or mucus. In addition, a chest X-ray, although it cannot detect the asbestos fibers themselves, can detect early signs of lung disease caused by asbestos. (1)

Health Hazard Information

Acute Effects:
• No studies were located on the acute (short-term) toxicity of asbestos in animals or humans. (1-4)
Chronic Effects (Noncancer):
• Chronic inhalation exposure to asbestos in humans can lead to a lung disease called asbestosis, which is a diffuse fibrous scarring of the lungs. Symptoms of asbestosis include shortness of breath, difficulty in breathing, and coughing. Asbestosis is a progressive disease, i.e., the severity of symptoms tends to increase with time, even after the exposure has stopped. In severe cases, this disease can lead to death, due to impairment of respiratory function. (1,2)
• Other effects from asbestos exposure via inhalation in humans include pulmonary hypertension and immunological effects. (1,2)
• Feeding studies in animals exposed to high doses of asbestos have not detected any evidence of adverse toxic effects. (1,2)
• EPA has not established a Reference Concentration (RfC) or a Reference Dose (RfD) for asbestos. (5)
Reproductive/Developmental Effects:
• No studies were located on the developmental or reproductive effects of asbestos in animals or humans via inhalation. (1,2,3)
• Birth defects were not noted in the offspring of animals exposed to asbestos in the diet during pregnancy. (1)
• No effects on fertility were observed in animals exposed to asbestos in the diet during breeding, pregnancy, and lactation. (1)