Asbestos Increased Risk Of Developing Malignant Mesothelioma. A new study published in the October 2005 American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine has found that Californians who live close to naturally occurring asbestos sources are at an increased risk for developing malignant mesothelioma.
Malignant mesothelioma is a cancer of the membrane covering the lung. The study’s authors, Marc B. Schenker, M.D., from the University of California, Davis, and four of his associates, investigated 2,908 malignant mesothelioma cases reported in California between 1988 to 1997. Over half of the patients either had no or low occupational exposure to asbestos. Exposure to asbestos fibers is the only known cause for malignant mesothelioma.
Dr. Schenker said that while studies have confirmed the link between mesothelioma and occupational exposure to asbestos, almost all population-based studies have found that many mesothelioma cases have no known occupational exposure to asbestos.
Asbestos Risk Of Developing Malignant Mesothelioma
The research showed that people who lived closer to an asbestos source had a greater risk of developing mesothelioma, and that the chance decreased as the distance from exposure increased. According to the study, the odds of developing mesothelioma decreased 6.3 percent for every 10 kilometers farther from the asbestos source.
Per the authors, California has more naturally occurring asbestos source rocks than any other state in the U.S..
In an editorial in the same issue, Marcel Goldberg, M.D., Ph.D. and Daniele Luce, Ph.D., of the Institut National de la Sante et de la Recherche Medicale in Saint Maurice, France, wrote “while exposure in environmental settings is generally much lower than in occupational circumstances, the levels may not be negligible.”
They add that in studies in which elevated risk of mesothelioma was demonstrated, people typically lived in close vicinity of naturally occurring asbestos sources. “It is thus likely that lifelong cumulative exposure may have been as high (if not higher) as in some occupational settings.”