title: Pathogenicity of inhaled nickel compounds in hamsters.
abstract: To investigate the pathogenicity of nickel oxide (NiO), hamsters received life-span exposures to that compound (approximately 55 mg/m3) seven hours per day, five days per week. Heavy pulmonary nickel oxide burdens resulted in pneumoconiosis but in no significant carcinogenicity, specific toxicity, or mortality. Two-month exposures of hamsters to nickel-enriched fly ash (NEFA) or fly ash (FA) aerosols (approximately 185 mg/m3) resulted in a deep lung burden of about 5.7 mg, dark discoloration of lungs, heavily dust-laden macrophages, and significantly higher lung weights than in controls, but only minimal inflammatory reaction and no deaths. The NEFA contained 9% nickel; FA contained 0.03% nickel. Exposure to aerosols of NEFA (70 or 15 mg/m3; 6% nickel) or FA (70 mg/m3; 0.3% nickel) for 20 months had no effect on body weight or life-span of the animals. Lung weights and volumes of the high-NEFA- and FA-exposed animals were higher than those of the low-NEFA group and controls. The incidence and severity of interstitial reaction and bronchiolization were significantly higher in the dust-exposed groups than in the controls. The severity of dust deposition, interstitial reaction, and bronchiolization was significantly lower in the low-NEFA group than in the high-NEFA and FA groups. Our findings revealed no significant nickel-specific toxicity/carcinogenicity in hamsters exposed to aerosols of nickel oxide or NEFA, but exposure to high concentrations of the oxide resulted in nonspecific dust pneumoconiosis.
mesh_terms: D000336:Aerosols; D000818:Animals; D002244:Carbon / Q000633:toxicity; D060729:Coal Ash; D006224:Cricetinae; D006965:Hyperplasia; D008168:Lung / Q000473:pathology*; D008175:Lung Neoplasms / Q000139:chemically induced; D008297:Male; D008647:Mesocricetus; D009532:Nickel / Q000633:toxicity*; D052638:Particulate Matter; D011009:Pneumoconiosis / Q000209:etiology* / Q000473:pathology; D012513:Sarcoma, Experimental / Q000139:chemically induced
chemical_list: D000336:Aerosols; D060729:Coal Ash; D052638:Particulate Matter; D002244:Carbon; D009532:Nickel; C028007:nickel monoxide