Laurel Beckett, professor and vice chair of the UC Davis Department of Public Health Sciences and a study co-author, said the findings are important. "We showed that breathing asbestos in your community is not magically different from breathing asbestos in an industrial setting. It would have been a surprise to find otherwise."
Similarly, she said, it was no real surprise to scientists when passive smoking was found to cause lung cancer. "Like smoking, exposure to asbestos appears to be very dose-dependent," Beckett said. "Day-in, day-out occupational exposures are more dangerous than intermittent exposures in the community. But the more you can do to reduce your personal exposure, the safer you will be."
While the overall mesothelioma rate was about one case per 100,000 people per year in the California study, the rate varied markedly by gender and age. For white males, the rate was 2.29 cases per 100,000. For white females, it was 0.49. People over age 60 had ten times the rate of those ages 40 to 59.
Worldwide, epidemiological studies of mesothelioma have found occupational causes for most but not all cases of the disease. In some undeveloped areas of the world, including parts of Greece and Turkey, mesothelioma cases have been linked to use of naturally occurring asbestos in household materials such as whitewash. The UC Davis study suggests naturally occurring asbestos also causes mesothelioma in developed countries, through incidental, non-occupational exposures.
California has required statewide cancer reporting since 1985 and established the California Cancer Registry in 1988. One of the largest cancer databases in the world, the registry is responsible for collecting cancer incidence and mortality statistics for more than one tenth of the United States population. An estimated 98.9 percent of all mesothelioma cases diagnosed in California are reported to the registry.
The registry's size enabled researc
Source:University of California, Davis - Health System