TOXICOLOGICAL PROFILE FOR CHROMIUM - Davidborowski.com

CHROMIUM 1872. HEALTH EFFECTSThe threshold concentration of extractable chromium(VI) in solid material was considered by Stern et al.(1993) to be as low as 10 ppm. The lowest observed effect level for elicitation of allergic contactdermatitis from ingestion of chromium(VI) was considered to be 0.26 ppm. In regard to the thresholdconcentration of chromium(VI) in soil for elicitation of contact dermatitis, the extractability ofchromium(VI) from soil matrix was considered to be a factor. The effective concentration at the surfaceof the skin is determined by the concentration of chromium(VI) in solution following extraction from soilmatrix. A study by Horowitz and Finley (1993) suggests that dermal contact with soil contaminated withchromite ore processing residue would probably not elicit allergic contact dermatitis in sensitizedindividuals. This study estimated that 0.1% or less of the chromium(VI) in chromite ore processingresidue would leach out in the presence of human sweat. Thus, the chromium(VI) concentration in thesoil would have to be 10,000–54,000 ppm (estimation based on 10–54 ppm sensitization elicitationthreshold).An inhalation immunological study in rats indicated that sodium dichromate stimulated the humoralimmune system, affected the T-lymphocytes, and increased the phagocytic activity of macrophages(Glaser et al. 1985). Pulmonary inflammation was indicated in rats repeatedly exposed to atmospherescontaining soluble potassium chromate, as evidenced by increases in total recoverable cells, neutrophils,and monocytes in bronchoalveolar lavage, and reduced percentages of pulmonary macrophages (Cohen etal. 1998); this was not seen in rats similarly exposed to insoluble barium chromate. Splenocytes from ratsthat were exposed to potassium chromate in the drinking water showed increased proliferative responsesto T- and B-cell mitogens and to the antigen mitomycin C. The response to mitomycin C was enhanced5-fold when potassium chromate was added to splenocytes from chromium(VI)-exposed rats, indicating asensitization phenomenon (Snyder and Valle 1991). Contact dermatitis has been elicited in guinea pigsand mice by both chromium(VI) and chromium(III) compounds (Gross et al. 1968; Jansen and Berrens1968; Mor et al. 1988).Since exposure to low levels of chromium as found in consumer products can result in sensitization,hypersensitive individuals may develop rashes and erythema from contact with soil contaminated withhigh concentrations or consumer products containing chromium.Neurological Effects. Information regarding neurological effects after exposure to chromium or itscompounds is limited. Dizziness, headache, and weakness were experienced by workers in a chromeplating plant where poor exhaust resulted in excessively high concentrations of chromium trioxide(Lieberman 1941). Such poor working conditions are unlikely to still exist in the United States due to