Subchronic inhalation toxicity of soluble hexavalent chromium trioxide in rats.
We performed a 90-day repeated-dose inhalation toxicity study of soluble hexavalent chromium trioxide (CrO3 (VI)). Male Sprague-Dawley (SD) rats were exposed to doses of CrO3 in the form of 0.5 approximately 5.0 microm aerosol at 0.00, 0.20, 0.50, and 1.25 mg/m3 for 6 h/day, 5 days/week for 13 weeks using inhalation chamber. CrO3 induced decrease of activity, alopecia and nasal hemorrhage. Body weights of the high-dose 1.25-mg/m3 exposure group were significantly lower than those of the control group. Hematological results revealed the reduction of the number of red blood cell and hematocrit values in the 1.25-mg/m3 exposure group. In addition, the hemoglobin values in the 0.50- and 1.25-mg/m3 exposure groups were significantly decreased compared with those of the control group. Clinical biochemical measurements revealed the reduction in total protein, albumin and alanine aminotransferase (ALT) level of the 0.50- and 1.25-mg/m3 exposure groups. Microscopic examination of the lung showed inflammation reactions caused by Cr exposure. In conclusion, the 13-week repeated exposure with soluble CrO3 demonstrated the injury in SD rats with the no observed adverse effect level (NOAEL) under 0.20 mg/m3.
Kim
Hyeon-yeong
HY
Occupational Safety and Health Research Institute, Center for Occupational Toxicology, 108-4 Munji-dong, Yusong-ku, 305-380, Daejeon, Korea. kk3843@yahoo.co.kr
Lee
Sung-bae
SB
Jang
Beom-su
BS
D000280:Administration, Inhalation; D000336:Aerosols; D000395:Air Pollutants, Occupational / Q000633:toxicity*; D000818:Animals; D001772:Blood Cell Count; D001835:Body Weight / Q000187:drug effects; D002857:Chromium / Q000008:administration & dosage / Q000633:toxicity*; D017608:Chromium Compounds / Q000008:administration & dosage / Q000633:toxicity*; D004435:Eating / Q000187:drug effects; D008168:Lung / Q000187:drug effects / Q000473:pathology; D008297:Male; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility; D013997:Time Factors
D000336:Aerosols; D000395:Air Pollutants, Occupational; D017608:Chromium Compounds; D002857:Chromium; C074702:chromium hexavalent ion; C028801:chromium trioxide