Asbestos: An Environmental Hazard

Asbestos has been used extensively as an insulating material in building construction for many years. Only until recently were newer materials introduced in the market such as fiberglass in place of asbestos.

Diseases may result when large amounts of fine asbestos fibers become accumulated in the lungs. This fatal disease is more commonly known as asbestosis. The disease is often found in workers engaged in the mining or processing of asbestos. Various trades involved with asbestos include pipefitting, shipbuilding and the construction industry. In addition to its use in insulation, it is also used in fire smothering blankets and safety clothing, in gas masks, as plastic filler material and in cement and floor tiles. Today, demolition workers and home renovators working on older buildings put themselves at high risk from the toxicity of this substance.

One of the most fatal toxicities of asbestos is its effect on breathing and the pathogenesis of lung cancer. The lungs are the primary targets of asbestos toxicity. Breathing may become progressively more difficult and laborious and this may ultimately lead to lung cancer. Initially, the individual may only experience a chronic, dry cough. As the disease progresses, symptoms may vary from shortness of breath and decreased exercise tolerance to chest pains. These symptoms are not exclusive to asbestosis, but a history of exposure will help the physician make the right and acute diagnosis of this disease.

One rare form of lung cancer that appears to be unique among people exposed to asbestos is known as mesothelioma. This cancer affects the lining of the lungs or abdomen. The association of asbestos exposure and malignant mesothleioma has been well documented. Approximately 80% of mesothelioma patients have along history of asbestos exposure. The combined roles of genetic and environment in the pathogenesis of mesothelioma has also been suggested by its familial aggregation. Studies show an association between single nucleotide polymorphisms leading to a defect in DNA repair poses an increased risk of mesothelioma. It is essential to identify genetic risk factors for malignant mesothelioma. The toxic asbestos fibers chronically retained in the lung can be carcinogenic as a result of: mechanical effects, such as interference during chromosome segregation; generation of reactive oxygen species; and local and systemic immunosuppression. Identification of specific risk genotypes will provide better estimation of population disease risk resulting from defined exposure; improve knowledge on lung carcinogenesis; and help target early detection of disease in high-risk individuals. It is a malignant neoplasm that may not appear for as many as 20 to 40 years following the exposure of the substance. This type of malignancy has a high fatality rate. The relation between asbestos exposure and mesothelioma is so close that the occurrence of this malignancy may be grounds for occupational compensation.

Unfortunately, there has yet been no cure for asbestosis. It is imperative that one provides a detailed history of work activities and any other sources of possible exposure to toxic dusts. Keep in mind that ones' exposure may have been many years ago. The substance may have been inhaled from the clothes of another person who has worked with asbestos. An abnormal finding chest X ray may suggest exposure to asbestos. This does not necessarily mean that you have lung asbestosis. Not everyone who has been exposed will inevitably develop lung disease and cancer. The disease itself is only diagnosed only if you have a history of exposure, indicative chest X ray and physical findings and symptoms of debilitating lung fibrosis, which is characterized by abnormal development of scar tissue in the lungs.

If you are a young or middle-aged worker who works with asbestos, it is important to follow recommended safety precautions. Wear approved facemasks and breathing instruments that filter out the asbestos fibers. Be certain that all areas of your body is covered and take extra care to minimize your contact with the outside of the clothes you wear when working with asbestos.

Michael Russell Your Independent guide to Asbestos