TOXICOLOGICAL PROFILE FOR CHROMIUM - Davidborowski.com

CHROMIUM 552. HEALTH EFFECTSwith controls (sister chromatid exchange was not evaluated in "bright" platers), and smoking appeared toenhance the increase (7 of 8 smokers and 7 of 11 nonsmokers had incidences significantly higher thancontrols). Moreover, the increased incidence of sister chromatid exchange showed a positive correlationwith urinary chromium levels (Sarto et al. 1982). Repeated cytogenetic analysis of peripherallymphocytes for 3 years revealed an increased frequency of chromosomal aberrations and sisterchromatid exchanges in a group of stainless steel welders compared to controls. The workers wereexposed to unreported chromium(VI) concentrations for a mean of 12.1 years, but exposure to ultravioletrays and small amounts of manganese, nickel, iron, and magnesium could not be ruled out (Koshi et al.1984). Compared to 39 controls, significantly elevated sister chromatid exchange values in lymphocytesand significantly higher rates of DNA single-strand breakages were found in a group of 39 weldersexposed to unreported chromium(VI) and nickel concentrations (Werfel et al. 1998). Only one study waslocated regarding the average levels of exposure for electroplating workers: workers exposed to anaverage level of 0.008 mg chromium(VI)/m 3 had increases in chromosomal aberrations and sisterchromatid exchanges. However, high levels of nickel as well as chromium were found in hair and stoolsamples when compared to controls (Deng et al. 1988). Thus, although most studies gave negative orequivocal results, chromium and its compounds, particularly chromium(VI), may cause chromosomaleffects in exposed workers, indicating carcinogenic potential because interactions with DNA have beenlinked with the mechanism of carcinogenicity.No elevated levels of DNA strand breaks or hydroxylation of deoxyguanosine in lymphocytes were foundin 10 workers occupationally exposed in the production of bichromate when compared with 10 nonoccupationally-exposedworkers at the same facility Gao et al. (1994). From general backgroundmonitoring levels of chromium(VI), exposures were estimated to be between 0.001 and 0.055 mg/m 3 .Information regarding genotoxic effects in animals after inhalation exposure to chromium or itscompounds is limited. Sprague-Dawley rats that inhaled chromium fumes generated from powders ofchromium metal by a plasma flame thrower at 1.84 or 0.55 mg chromium(0)/m 3 (5 hours/day,5 days/week) for 1 week or 2 months, respectively, had increased frequencies of chromosomal aberrationsand sister chromatid exchanges in peripheral lymphocytes, but not in bone marrow cells (Koshi et al.1987). Some oxidation of metallic chromium may have occurred in the process of generating thechromium fumes (IARC 1990).Other genotoxicity studies are discussed in Section 2.5.