Investigation of Effects of Prolonged Inhalation of Nickel-Enriched Fly Ash in Syrian Golden Hamsters

摘要

Groups of 102 Male Syrian Golden hamsters were chronically exposed to approx. 70 micrograms/l respirable Nickel Enriched Fly Ash aerosol (high NEFA group), approx. 17 micrograms/l (low NEFA group), or approx. 70 micrograms/l FA 6 hrs/day, 5 days/week for 4, 8, 12, 16 and 20 months. Identical control groups received sham exposures. The NEFA particles of respirable size contained approximately 6% nickel, compared to about 0.3% for FA. Exposure to NEFA had no significant effect on the apparent well being, body weight and life span of the animals although heavy deposits of NEFA in the lungs were found. The lung weights and mean lung volumes of the high NEFA and FA exposed animals were significantly higher and larger, respectively, than for the low NEFA and control groups. There was a 100% incidence of dust deposition (anthracosis) and significantly higher incidence plus severity of interstitial reaction and bronchiolization in the dust-exposed groups than the controls. The severity of lung reactions was significantly lower in the low NEFA group than the high NEFA and FA groups. The results of this study conclude that the addition of nickel to fly ash under these conditions did not significantly (P< 0.05) enhance the pathogenicity (including carcinogenicity) of fly ash in this animal model.