Absorption of 14C-Cyclotrimethylenetrinitramine (RDX) from Soils through Excised Human Skin

ABSTRACTCyclotrimethylenetrinitramine (RDX), a compound used widely in bursting-type munitions, is a concern for the U.S. Department of Defense because it has been detected in soil and groundwater at military installations. Dermal absorption of 14C-RDX from acetone solutions and from two different soils was studied using excised human skin (from surgery) in flow-through diffusion cells. RDX in acetone (10 μL) or in soils (10 mg) was applied to the epidermal surface of the skin (0.64 cm2) and allowed to transverse the skin and become dissolved in a reservoir of receptor fluid that was maintained in contact with the dermal surface. The reservoir was of the flow-through type and receptor fluid was pumped at a rate of 1.5 mL/h. Receptor fluid was collected every 6 h for 24 h. Because the bioavailability of a chemical from soils depends on soil composition, dermal absorption of 14C-RDX from both a low-carbon (1.9%) and a high-carbon (9.5%) soil was assessed. At the conclusion of the experiment, the RDX remaini...