10 July 2011

New Report on Carcinogens Lists Asbestos; Fiber Causes Lung Cancer, Mesothelioma

The 12th Report on Carcinogens, a science-based, public health document mandated by Congress, reaffirms the toxicity of asbestos in all forms.

The report, released Friday by the U.S. Department of Health and Human Services, identifies substances, chemicals, metals, pesticides, drugs and compounds that are known or reasonably expected to cause cancer in humans. The report lists 54 substances as known carcinogens and 186 substances that are suspected of causing cancer in humans.

As a senior health official at the National Toxicology Program, which prepared the report, noted, the Report on Carcinogens underscores the critical connection between what’s in the environment and public health.

There is no better example of the intersection between environmental exposure and human health than asbestos— a material once promoted as a wonder fiber.

A mineral fiber, asbestos was widely used in building materials in homes, schools, factories and other industrial settings for much of the 20th century. Its use was largely restricted in the late 1970s because of its toxicity. Yet, workers and their families who breathed asbestos dust decades ago still suffer the symptoms of asbestos-caused cancer. Approximately 3,000 new cases of mesothelioma, the signature cancer of asbestos, are diagnosed each year in the United States and tens of thousands worldwide.

Substances such as asbestos are listed as known carcinogens when there is a convincing body of evidence from peer-reviewed scientific studies involving humans to show a cause-and-effect relationship between exposure and development of cancer. Asbestos has been listed as a known carcinogen since publication of the 1st Report on Carcinogens in 1980. Scientific studies have found that occupational exposure to all forms of asbestos including chrysotile, amosite, anthophyllite, mixtures containing crocidolite,  and various mixtures of asbestos, increases the risk of cancer, according to the U.S. Department of Health and Human Services.

Asbestos was widely used in building materials and automotive parts until the late 1970s. It remains in many older buildings and is still used in some industrial applications, creating ongoing occupational hazards.

Workers exposed to airborne asbestos in the workplace or over a prolonged period are at highest risk of inhaling asbestos fibers and developing asbestos-related disease. New York has many at-risk job sites for asbestos exposure.  Symptoms of asbestos-related disease typically appear 20 to 50 years after asbestos exposure.

Among the newly listed known human carcinogens on the 12th Report on Carcinogens are the industrial chemical formaldehyde and the family of aristolochic acids. Formaldehyde is a colorless, flammable, strong smelling chemical used as a preservative and to make resins for building materials, wood products, paper coatings and textile finishes.

Aristolochic acids are a family of acids found naturally in the plants Asarum and Aristolochia. The plants are often used as herbal medicines used to treat arthritis, gout and inflammation.

Glass wool is among the newly listed suspected human carcinogens in the 12th Report on Carcinogens. A synthetic fiber, glass wool is used in building insulation and in special use applications as high-efficiency air filters and in aircraft and spacecraft insulation. Scientific studies involving animals show that glass wool causes cancerous tumors in animals’ lungs. The ability of glass wool fibers to cause cancer in animals varied depending on the types of fibers.

Much like asbestos fibers, glass wool fibers that are biopersistent and remain in the lungs are most associated with causing cancer. Asbestos was used to make insulation and insulation wrap. Older homes and buildings may contain vermiculite insulation containing asbestos.

Source: AboutMesothelioma.Net. By Wade Rawlins. Monday, 13 June 2011

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