The oncogenic action of nonfibrous mineral dusts

: Nonfibrous mineral dusts antigorite, basalt, cement, zeolite-klinoptilolite and gamma-alumina were tested for carcinogenic activity in rat experiments. Intraperitoneal injections of zeolite-klinoptilolite and gamma-alumina led to development of peritoneal mesotheliomas, whereas antigorite and cement had no carcinogenic potential. There is no differences in physicochemical and chemical properties between carcinogenically active and inactive nonfibrous dusts. A new class of carcinogenic substances is defined including basalt, zeolite-klinoptilolite and quartz which belong to nonfibrous mineral dusts.