TOXICOLOGICAL PROFILE FOR CHROMIUM - Davidborowski.com

CHROMIUM 1332. HEALTH EFFECTSChromium may be transferred to fetuses through the placenta and to infants via breast milk. Analysis ofchromium levels in women employees of a dichromate manufacturing facility in Russia during and afterpregnancy revealed that the exposed women had significantly higher levels of chromium in blood andurine during pregnancy, in umbilical cord blood, placentae, and breast milk at child birth, and in fetusesaborted at 12 weeks than did nonexposed controls (Shmitova 1980). The reliability of this study issuspect because the levels of chromium reported in the blood and urine of the control women were muchhigher than usual background levels of chromium in these biological fluids (see Section 5.5), perhaps dueto problems with analytical methods. Measurement of the chromium content in 255 samples from45 lactating American women revealed that most samples contained kidney > gastrointestinal tract > erythrocytes > liver >serum > testis > skin. Twenty-five days after dosing, the tissue distribution was lung > kidney >erythrocytes > testis > liver > serum > skin > gastrointestinal tract. Kidney, erythrocytes, and testismaintained their chromium levels for a period of 10–15 days before decreasing (Weber 1983). Thedistribution of chromium(VI) compared with chromium(III) was investigated in guinea pigs afterintratracheal instillation of potassium dichromate or chromium trichloride. At 24 hours after instillation,11% of the original dose of chromium from potassium dichromate remained in the lungs, 8% in theerythrocytes, 1% in plasma, 3% in the kidney, and 4% in the liver. The muscle, skin, and adrenal glandscontained only a trace. All tissue concentrations of chromium declined to low or nondetectable levels in140 days with the exception of the lungs and spleen. After chromium trichloride instillation, 69% of thedose remained in the lungs at 20 minutes, while only 4% was found in the blood and other tissues, withthe remaining 27% cleared from the lungs and swallowed. The only tissue that contained a significantamount of chromium 2 days after instillation of chromium trichloride was the spleen. After 30 and60 days, 30 and 12%, respectively, of the chromium(III) was retained in the lungs, while only 2.6 and1.6%, respectively, of the chromium(VI) dose was retained in the lung (Baetjer et al. 1959a).