A new study published in June issue of the American Journal of Industrial Medicine reports excessive rates of pleural mesothelioma and bladder cancer among workers at a major chlorine chemical plant in France. Pleural Mesothelioma is an aggressive cancer of the lining of the lungs associated with exposure to asbestos.
The study, performed by French researchers in Grenoble, France, analyzed the incidence of tumors from 1979 to 2002 among 2,742 men who worked at the chlorine plant. The study found an significant excess of mesothelioma tumors among workers hired before 1964.
France now bans asbestos because it’s a known cause of cancer, including pleural mesothelioma, peritoneal mesothelioma and lung cancer. But for many years, asbestos was used in the diaphragm-cell process of making chlorine. Asbestos is still used in chlorine manufacturing plants in the U.S. Workers may be exposed to asbestos when transporting sacks of asbestos or when cutting open and emptying sacks of asbestos into mixing tanks. The handling of the empty sack also presented an exposure hazard.
Unlike France, asbestos is not banned in the United States, though its use has dropped significantly since its peak in the 1970s. But the chlorine manufacturing industry remains a significant consumer of asbestos in the U.S. Many older chlorine plants in the U.S. use asbestos diaphragms and gaskets as part of the production process, putting workers at risk of exposure to asbestos. Some have converted their chlorine manufacturing processes to more environmentally friendly, safer technology that do not use asbestos.
According to the 2012 United State Geological Survey of mineral commodities, U.S. industries consumed 1,100 metric tons of asbestos from January through July 2011. The chlorine manufacturing industry, which uses asbestos diaphragms in the manufacturing of industrial chemicals, accounted for about 30 percent of asbestos consumption, the report said.
As a result of past asbestos use in the U.S., Americans are now dying from asbestos cancers and asbestosis, a chronic scarring of the lungs, at the rate of 10,000 people per year, according to Barry Castleman, an environmental and public health consultant who testified before the U.S. Senate Environmental and Public Works Committee in June 2007.
Symptoms of mesothelioma typically take 20 to 50 years to appear after workers inhale microscopic asbestos fibers. Many workers exposed to asbestos in the 1960s or 1970s may only recently have begun noticing symptoms such as pain beneath the ribs or shortness of breath or only been diagnosed with mesothelioma or asbestos disease.
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