Subchronic Inhalation Toxicity of Nickel Subsulfide to Rats and Mice

Abstract

AbstractInhalation studies conducted on nickel subsulfide (Ni3S2 have shown this compound to be highly toxic to the respiratory tract of rats and mice exposed for 12 d. To assess the subchronic inhalation toxicity of Ni3S2, groups of F344/N rats and B6C3F1 mice were exposed to 0, 0.11, 0.22, 0.44, 0.88, and 7.8 mg Ni/m3 (as Ni3S2), 6 h/d, 5 d/wk, for 13 wk. Concentrations of Ni in lungs of rats and mice exposed for 73 wk were similar, but the incidence and severity of the toxic effects of Ni3S2 exposure were greater among rats than mice. Exposure resulted in depressed weight gain and increased lung weights. Inhalation of Ni3S2 did not affect motility, viability or morphology of sperm in males, nor did it alter the estrous cycle length of females. Major histopathological lesions related to nickel exposure occurred in the nose, lung, and lung-associated lymph nodes of both species. The major findings were focal chronic inflammation of the lung, atrophy of the olfactory epithelium, and hyperplasia of the bro...