Volcanic mineral called erionite linked to mesothelioma

High exposure to a fibrous volcanic mineral called erionite was associated with a high incidence of a type of cancer called mesothelioma, according to a study in the Journal of the National Cancer Institute.

Many cases of environment-related mesothelioma have been reported in the Cappadocia region or Anatolian plateau of Turkey. Blocks of erionite from volcanic tuff have been used in construction, and storage rooms for produce have been cut in the tuff. Past reports have suggested that erionite exposure may increase the risk of mesothelioma, and studies have shown that erionite is associated with a higher risk of cancer development in animals than any other fiber previously tested.

Y. Izzettin Baris, M.D., of Hacettepe University in Ankara, Turkey, and colleagues followed 891 men and women age 20 years and older in three villages in Turkey - two exposed to erionite, one control - for 23 years. During this period, 372 deaths occurred, and 119 of these deaths occurred from mesothelioma. This form of cancer mainly affects the lining of the lung and was the cause of 44.5% of all deaths in the two villages with erionite exposure. Only two cases of mesothelioma occurred in the control village, both in people born outside of the control village.

The mortality data were analyzed jointly with Philippe Grandjean, M.D., Ph.D., of the Harvard School of Public Health. When standardized to the world population, the annual incidence of pleural mesothelioma in the two exposed villages was 200 and 700 cases per 100,000 people annually, compared to a rate of 10 cases per 100,000 people each year in the control village. The authors conclude that the long-term exposure to erionite is the cause of the exceedingly high risk of developing mesothelioma.

"Our results emphasize the severity of the mesothelioma endemic in erionite-exposed areas of Turkey," the authors write. They add, "In the rural part of central Anatolia, Turkey, millions of inhibitants are likely exposed to hazardous amounts of mineral fibers from the environment. Resources should therefore be directed to preventing these environmental exposures and additional study of the association between environmental exposure to nonasbestos fibers and the risk of cancer."