Everyday exposure to naturally occurring asbestos increases the risk of developing malignant mesothelioma, according to a study by UC Davis researchers. The study - the largest to examine the question - will be published this fall in the American Journal of Respiratory and Critical Care Medicine. Exposure to asbestos in the workplace, particularly in shipyards, has long been recognized as a risk factor for mesothelioma, a rare form of cancer affecting the lining of the lung. But in the new study, researchers found a consistent and dose-dependent association between mesothelioma and residential proximity to ultramafic rock, the predominant source of naturally occurring asbestos. "Our findings indicate that the risks from exposure to naturally occurring asbestos, while low,...