Libby, Montana is a town that sits on a bend of the Kootenai River that flows south from Canada toward the Columbia River. East of Libby lies the Zonolite Mountains that contains an asbestos mining facility which opened in 1924. More than 1,900 men worked in this mine processing an astonishing amount of asbestos.
At the peak of production, nearly 500,000 lbs of asbestos a day went through the "dry mill," which is the primary processing facility and dustiest building on the property. Tests showed that as much as 24,000 lbs of dust a day were removed from the stack on the dry mill. The dust was made up of about 20% asbestos. It was common for this dust to cover the mine buildings and for the wind to blow the dust toward Libby, covering the town. It was not unusual for the clothes hanging on clotheslines to be covered with asbestos containing dust, or for children to write their names in the dust that layered the cars.
The Most Deadly Fibers: Tremolite
The asbestos from the Zonolite mine was made up of tremolite. While all types of asbestos are extremely dangerous when inhaled, tremolite fibers are the most deadly. The fibers are needle-like and sharply pointed. They can penetrate the lining of the lungs more easily when inhaled and cause more irritation to the lung pleural. These fibers will never leave the body, and over time the scarring of the lungs turns into a disease called asbestosis. During asbestosis, the scar tissue causes the lung to lose functioning and the patient loses his or her ability to breath. Eventually, the scar tissue completely envelopes the lungs and either the lungs fail completely or the heart beating from exhaustion.
The occurances of mesothelioma has been directly linked to tremolite and other types of asbestos exposure. Since scarring of the lungs can continue for decades after exposure to asbestos, there is a very long latency for mesothelioma. Although the mine closed in 1990, doctors from the Libby area suggest that people from Libby will be dying from asbestos related diseases for years to come. X-rays taken while the mine was still operating showed that almost half of the people who had worked at the mine for 11 to 20 years had lung disease of some type. Ninety-two percent showed signs of lung disease for those miners who had worked at the mine for 21 to 25 years.
The asbestos exposure in Libby was highest for the workers in the mine, but as described earlier, the mine generated tons of asbestos dust that became a hazard to the town's people. Furthermore, W.R. Grace and Company, the owner of the mine, did not provide showers or a change of clothing for the miners. These deadly asbestos fibers traveled from the mine to the families of the miners as dust on the miners’ clothing. A large number of miners and family members have died in Libby due to asbestos-related diseases, including mesothelioma cancer since there is no effective form of mesothelioma treatment.
Vermiculite and Asbestos in Libby, MT
In addition to the asbestos deposits, the Libby area also has enormous deposits of vermiculite. In the area of the vermiculite deposits, tremolite asbestos laid undisturbed under a thin layer of top soil. When the vermiculite mining began, these deadly asbestos fibers were awoken and released into the air. In 1999, statistics revealed that 12 to 15 people a month from Libby were being diagnosed with the asbestos related diseases of asbestosis, malignant mesothelioma and lung cancer after experiencing a symptom of mesothelioma or related disease.
Although the vermiculite mines are closed in Libby, vermiculite that was extracted from the Libby mines may continue to pose a health risk. Vermiculite is used in insulation and construction materials. If these materials were used in a building and then become disturbed during demolition or other movement, the asbestos fibers may become airborne. When in the air, these fibers can be inhaled and then penetrate the lining of the lungs. Tremolite asbestos fibers are particularly sharp and needle-like, thus causing more lung penetration and irritation with fewer fibers.
In cases where asbestos containing vermiculite must be removed, standard hazardous material handling protocols should be used. Before removing and destroying any construction materials, it is best to have them tested for asbestos.
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