TOXICOLOGICAL PROFILE FOR CHROMIUM - Davidborowski.com

CHROMIUM 1042. HEALTH EFFECTS2.2.2.6 Developmental EffectsNo studies were located regarding developmental effects in humans after oral exposure to chromium or itscompounds.Several animal studies provide evidence that chromium(VI) is a developmental toxicant in rats and mice.A series of studies (Junaid et al. 1996a; Kanojia et al. 1996, 1998) was conducted to assess whether prematingexposure to potassium dichromate would result in developmental effects. In the first study,groups of 15 female Swiss albino mice were exposed to 0, 52, 98, or 169 mg chromium(VI)/kg/day aspotassium dichromate in drinking water for 20 days (Junaid et al. 1996a) and then mated with untreatedmales. At 52 mg chromium(VI)/kg/day, there was a 17.5% post-implantation loss over controls and a30% decrease in fetal weight. At 98 mg/kg/day, there were decreases in the number of implantation sites,the number of live fetuses, and the fetal weight. There were also increases in the number of resorptionsand the number of pre- and post-implantation losses. At 169 mg chromium(VI)/kg/day, there was 100%pre-implantation loss. The fetuses in the 98 mg/kg/day group had higher numbers of sub-dermalhemorrhagic patches and kinky short tails and decreased fetal body weight and crown rump length.Although there were no major skeletal abnormalities in any other treated animals, there was a significantreduction in ossification at 52 mg chromium(VI)/kg/day (53% compared to 12% for controls) andsignificant reduction in ossification in caudal, parietal and interparietal bones of fetuses at 98 mgchromium(VI)/kg/day. There were no significant soft tissue deformities in any of the treated fetuses.Although dosing occurred prior to mating, internal chromium levels remaining in females after matingmay have been toxic to the conceptus that caused adverse developmental effects.In the second study, female Swiss albino rats were exposed to potassium dichromate concentrations in thedrinking water resulting in doses of 37, 70, or 87 mg chromium(VI)/kg/day for 20 days prior to mating(Kanojia et al. 1996). Lower gestational weight gain, increased post-implantation loss, and decreasednumber of live fetuses were observed in all treatment groups, relative to controls. Increased incidences ofreduced fetal ossification in fetal caudal bones were reported at the 70 and 87 mg chromium(VI)/kg/daydose levels; additionally, the 87 mg chromium(VI)/kg/day dose group of fetuses exhibited increasedincidences of reduced ossification in parietal and interparietal bones, as well as significant incidences ofsubdermal hemorrhagic thoracic and abdominal patches (42%), kinky tails (42%), and short tails (53%),relative to 0% in controls. No treatment-related gross visceral abnormalities were seen.