Comparative chronic inhalation toxicity of beryllium ores, bertrandite and beryl, with production of pulmonary tumors by beryl

Abstract

Intermittent daily exposure of monkeys, rats, and hamsters for periods up to 23 months to 15 mg/m 3 of bertrandite or beryl ore dust resulted in the appearance of pulmonary tumors in 18 of the 19 rats that survived 17 months of exposure to beryl. Corresponding lesions were not observed in any of the other animals exposed to beryl or in those exposed to bertrandite. Bertrandite-exposed rats, however, exhibited granulomas and atypical proliferation of the lung. Monkeys from both ore exposures deviated from the unexposed control group only by a nonspecific phagocytic dust reaction around the respiratory bronchioles and small blood vessels. Beryl and bertrandite-exposed hamsters showed pulmonary atypical proliferation and the bertrandite animal lungs contained a few granulomatous lesions. Body-weight gains, except for the ore-exposed rats, corresponded with those of the control-unexposed animals. Mortalities in the ore-exposed animals exceeded those of the controls. Hematologic parameters of ore-exposed and control monkeys and rats were within accepted ranges. Alkaline phosphatase activities in lung, kidney, spleen, and serum samples from serially sacrificed animals of all species yielded equivocal data. Collagenous silicotic nodules did not develop in any ore-exposed animal despite an approximately 20% free-silica content of the ores sufficient to result in such a response.