The extractability of Cr(VI) from contaminated soil in synthetic sweat

Hexavalent chromium is a common skin irritant that can cause contact dermatitis in sensitized individuals. Soil samples from two chromium waste sites having different Cr(VI) concentrations were extracted in synthetic sweat solutions over a pH range of 4 to 8 and analyzed for Cr(VI). These extractions were performed to determine the potential availability of Cr(VI) from contaminated soils upon contact with human sweat. The samples were also extracted using the EPA Method 3060 alkaline digestion. Overall, hexavalent chromium was readily extractable from both samples in the solutions tested. One of the samples contained Cr(VI) crystals, known as blooms, and had a Cr(VI) concentration approximately 40 times greater than the sample without blooms. The pH of the synthetic sweat solution had little effect on the Cr(VI) concentration determined for the sample containing blooms, whereas the Cr(VI) concentration determined for the sample without blooms increased with increasing pH. The Cr(VI) extracted in the synthetic sweat solutions was consistently lower than the amount extracted by the EPA 3060 alkaline extraction.