In vitro Penetration of Pig Skin by Heavy Metals in Soil

摘要

The potential health risk from exposure to heavy metal contaminated soil is often based on the quantity of metal that can be removed from soil by vigorous extraction procedures. This approach can overestimate risk since it ignores complex interactions between metals and soil that can result in a reduction in the amount of metal that desorbs from soil and is subsequently absorbed by the body. The aim of this research was to determine the relative contribution of the soil matrix and heavy metal sequestration in soil with time ("aging") on the dermal penetration of arsenic, mercury, and nickel, respectively, as arsenic acid, mercuric chloride, and nickel chloride. In vitro flow-through diffusion cell studies were performed utilizing dermatomed male pig skin and radioactive compounds to measure total penetration (the sum of each metal in receptor fluid and skin). For arsenic and nickel, the soil matrix produced a 78-87% reduction in dermal penetration compared to 12-19% after aging. A greater effect was observed with aged mercury (52-56% decrease in dermal penetration) than in freshly spiked soil (40-43%). The results indicate that the potential health risk from dermal exposure to the metals can be significantly reduced by soil and aging.