TOXICOLOGICAL PROFILE FOR CHROMIUM - Davidborowski.com

CHROMIUM 1392. HEALTH EFFECTSred blood cells (.4 pg chromium/billion cells), and the amount of 51 chromium in the cells was the sameafter 24 hours as it was after 1 hour. The amount of 51 chromium in the white blood cells, but not in thered blood cells, decreased by approximately 1.7-fold after 7 days. When rats were injected intravenouslywith 20 ng of radiolabeled sodium chromate (chromium(VI)) or radiolabeled chromium trichloride(chromium(III)), the amount of chromium was .2 pg/billion red blood cells but not detectable in whiteblood cells after injection of chromium(III) chloride. The amount of chromium was .5 pg/billion redblood cells and .60 pg/billion white blood cells after injection of sodium chromate (Coogan et al. 1991b).The distribution pattern in rats treated with sodium chromite (chromium(III)) by intravenous injectionrevealed that most of the chromium was concentrated in the reticuloendothelial system, which, togetherwith the liver accumulated 90% of the dose. The accumulation in the reticuloendothelial system wasthought to result from colloid formation by chromite at physiological pH. Organs with detectablechromium levels 42 days postinjection were: spleen > liver > bone marrow > tibia > epiphysis > lung >kidney. Chromium trichloride given to rats by intravenous injection also concentrated in the liver, spleen,and bone marrow (Visek et al. 1953). In rats administered chromium(III) nitrate intraperitoneally for 30or 60 days, the highest levels of chromium were found in the liver, followed by the kidneys, testes, andbrain. The levels increased with increased doses but not linearly. The levels in the kidneys, but not theother organs, increased significantly with duration (Tandon et al. 1979).Whole-body analysis of mice given a single intraperitoneal injection of 3.25 mg chromium(III)/kg aschromium trichloride showed that chromium trichloride was released very slowly over 21 days: 87% wasretained 3 days after treatment, 73% after 7 days treatment, and 45% after 21 days. In contrast, micegiven a single intraperitoneal injection of 3.23 chromium(VI)/kg as potassium dichromate retained only31% of the chromium(VI) dose at 3 days, 16% at 7 days, and 7.5% at 21 days. Mice injected weekly withchromium(III) compounds at 17% of the LD 50 retained .6 times the amount of chromium as mice injectedwith chromium(VI) compounds at 17% of the LD 50 . The retention of chromium(III) was attributed to itsability to form coordination complexes with tissue components such a proteins and amino acids (Brysonand Goodall 1983).In rats injected intraperitoneally with 2 mg chromium(VI)/kg/day as potassium chromate 6 days/week for45 days, the mean levels of chromium (µg chromium/g wet weight) were 25.68 in the liver, 40.61 in thekidney, 7.56 in the heart, and 4.18 in the brain (Behari and Tandon 1980).