Asbestos Health Effects : Treatment

by CDC

(Page 9 of 9)

According to Mossman and Churg (1998), regulation of occupational exposures to minerals and removal of symptomatic persons from the workplace are important measures for prevention or amelioration. However, there has been little advancement in effective therapeutic strategies for patients. Ideopathic pulmonary fibrosis, silicosis, and asbestosis have traditionally been treated with corticosteroids or immunosuppressants, with discouraging results in terms of morbidity and mortality. Recent work has focused on the mechanisms of mineral-induced inflammation and fibrosis to develop novel treatments. Recent studies have addressed: administration of antioxidants or iron chelators, inhibition of tumor necrosis factor and interleukin factor-1, inhibition of phospholipases, and modification of mineral surface properties.

Follow-up of asymptomatic patients exposed to asbestos is recommended to facilitate early diagnosis and intervention. Periodic pulmonary function studies can be helpful in diagnosing early signs of asbestosis.

Patient education is an important factor in managing asbestos-associated diseases.

Management of asbestos-associated diseases begins with patient education regarding smoking cessation and avoidance of pulmonary infections. Awareness of early symptoms of other neoplasms, including hoarseness, sores in the mouth, blood in the urine, blood in the stool, and GI symptoms, is important. Persons exposed to asbestos should be advised of the increased risk for lung cancer and the synergistic effects of cigarette smoking, although smoking does not affect the development of mesothelioma. In general, explaining environmentally related cancer risk is difficult because extrapolation of risk from workplace data to environmental exposures is difficult or impossible for many substances. Maintaining a balance between appropriate concern and avoidance of undue alarm is the goal.

Asbestosis

Asbestosis patients should avoid pulmonary irritants and guard against lung infections.

Asbestosis is an irreversible pulmonary condition. Respiratory infections should be treated aggressively because they often prove fatal in patients with advanced fibrotic lung disease. Patients should be strongly advised to avoid all pulmonary irritants, including cigarette smoke. Influenza and pneumococcal vaccines highly recommended. In the later stages, pulmonary rehabilitation might be helpful. The patient should be advised to consult a physician when the first signs and symptoms of respiratory infection occur, so that early treatment can be instituted.

Although most investigators consider the pleural plaques associated with asbestosis to be benign, they can result in pulmonary impairment. Patients with pleural asbestosis are also more likely to have or develop parenchymal asbestosis and should be appropriately monitored. Patients should be informed that pleural plaques represent evidence of significant asbestos exposure.

Mesothelioma

Patients with mesothelioma have a 1-year survival rate of <30%.

The prognosis in this disease is difficult to assess consistently because there is great variability in the time before diagnosis and the rate of disease progression. However, the prognosis for patients with mesothelioma has traditionally been poor; they seldom live longer than 12 to 18 months after diagnosis. The 1-year survival rate of mesothelioma patients is <30%. Some indications show that early diagnosis and multimodal or new therapies might have an impact on survival. Among specialists at major cancer centers, statistics have shown some improvement: 5-year survival has approached 40% in selected patients. Clinical trials are also ongoing and might be useful for selected patients. (The National Cancer Institute Web page [www.nci.nih.gov]Exit ATSDR can provide more details.) Health-care providers should vigilantly monitor patients at risk for mesothelioma to find it as early as possible, especially when pleural effusion is present, and should consider consulting a specialist as indicated.

Lung Cancer

Treatment of asbestos-associated cancer does not differ from treatment for cancers due to other causes.

Treatment of asbestos-associated cancer should include appropriate combinations of surgery, chemotherapy, and radiation, according to accepted surgical and oncologic standards.

Standards and Regulations

Workplace

The Occupational Safety and Health Administration (OSHA) standard for asbestos in the workplace is 0.1 fibers/cc of air as an 8-hour TWA.

Widespread evidence of asbestos-associated disease in workers was found in the 1930s. A standard for exposure was not established in this country until 1960, but only in selected industries. In 1971, the standard was extended industry-wide. A 1968 British study judged that exposure to 2 fibers per cubic centimeter of air (fibers/cc) for the duration of a person's work life would result in an approximate 1% risk for asbestosis. This was an underestimation, but nonetheless led to the establishment of the 1976 U.S. standard of 2 fibers/cc as a time-weighted average (TWA). Further study of carcinogenicity resulted in the OSHA standard of 0.2 fibers/cc (8-hour TWA) that became effective in 1986. The level at which employers must take action to reduce employee exposure (termed "action level") is 0.1 fibers/cc (8-hour TWA).

Environment

The EPA maximum contaminant level (MCL) for asbestos in drinking water is 7 million fibers per liter of water.

The difficulties of controlling asbestos exposure in the workplace are paralleled in the general environment. EPA recommends "no visible emissions." In 1973, EPA banned spraying of asbestos in building interiors. No regulations for asbestos in potable water exist. The EPA proposed MCL for asbestos in drinking water is 7 million fibers (>10 microns in length) per liter of water.

The Asbestos in Schools Identification and Notification Act of 1982 requires that local education agencies inspect for friable material, analyze these materials for asbestos content, post results and notify parents and employees if asbestos is found, and maintain appropriate records. A recent study indicating that power-buffing and power-stripping of asbestos-tile floors in schools produces significant airborne-asbestos levels prompted an EPA warning to school communities. Floor maintenance will henceforth be performed by hand to prevent the release of fibers.

To protect both themselves and the environment, asbestos remediation workers should be trained to handle asbestos properly.

About the Author

www.cdc.gov
The Centers for Disease Control and Prevention (CDC) is one of the 13 major operating components of the Department of Health and Human Services (HHS), which is the principal agency in the United States government for protecting the health and safety of all Americans and for providing essential human services, especially for those people who are least able to help themselves.