When the government regulated the use of asbestos in construction material in the seventies, it recognized the dangers of prolonged exposure to the deadly fibers. Unfortunately, the ban on asbestos extended only to newer products that were produced, while the existing products that already contained asbestos remained without being discarded. These stocks of asbestos were used right up to the mid eighties, leading to the development of large numbers of products containing the material. One of these products was valve stem packing, and it was widely used in the heating, construction and ship building industry.
In order to be effective, valve stem packing had to seal the valve stem, so as to minimize the possibility of leakage. It also had to play a non interfering role in the functioning of the control valve. Asbestos was found to meet both these conditions, and its insulating properties were found to be perfectly suitable for use in the heating industry. In the decades between the thirties and seventies, asbestos was extensively used in valve stem packing. After the government introduced the ban, newer valve rings began to be made of Teflon. Older valve rings that were already in place in heating systems around the country were left as they were.
Prolonged exposure to asbestos has been linked to a number of diseases, most common of which are mesothelioma and asbestosis. Although direct exposure to the toxic substance in the construction industry or in shipyards has been found to have greater dangers, there is nothing that suggests that exposure to smaller amounts of the substance through the presence of smaller components, like valve rings, has ill heath effects.
The health effects of asbestos are many, but the most common diseases that can arise as a result of exposure to the toxic fibers are mesothelioma, and asbestosis. Of the two, mesothelioma is a painful form of cancer that has a long latency period of up to 40 years which makes it hard to diagnose. As the disease progresses, the person finds it increasingly difficult to breathe, because of the asbestos fibers that are lodged in the lining of the lungs. Asbestosis leads to scarring of lung tissue and increased difficulty in breathing. There is shortness of breath, coughing and the inability to exert oneself. In some cases, clubbing of fingers may be seen.
Newer cases of mesothelioma caused by exposure to asbestos in recent years can be traced to the demolition of old buildings. These structures always disperses millions of particles of asbestos fiber in the air during the process of abatement which can be highly hazardous to health. If you have asbestos containing products in your building, you are advised to consult an experienced abatement contractor who has the necessary equipment for the task.