Efficacy of Widely Available and Easy-to-Prepare Solutions for Skin Decontamination with Manganese-56 Chloride and Oxide as Models for Water-Soluble and Insoluble Radioactive Compounds.

Abstract

Radio nuclear attack scenarios are potential threats that state actors must deal with more than ever in the context of preparedness and response since the Cold War. Radioactive contamination can occur in many scenarios, which means that, in addition to increased skin- and whole-body doses from external radiation exposure, there is also a risk of incorporation and contamination carryover. In many contexts, only theoretical considerations have been made about which substances would be suitable for removing various radioactive compounds. The goal of this work is to systematically investigate the efficacy of various skin decontamination agents in aqueous solutions, e.g., soap, urea peroxide, EDTA, citric acid, and hydrochloric acid. As a model radionuclide we utilized Manganese-56 in two chemical forms: 1. 56MnCl2 and 2. 56MnO2. The contamination was deposited on the surface of ex vivo pig skin during a 15 min contamination protocol. Pre- and post-decontamination measurements were performed by using a lead-shielded gamma spectrometer in a standardized geometry. The counts in 180 s were analyzed after decay and background correction. The decontamination process involved a standardized 30-second spray followed by a single wipe on the pig skin performed by the same decontaminating experimenter. While the tested decontamination agents were approximately equally efficient in removing water-insoluble radioactive contamination (56MnO2), decontamination from water-soluble 56MnCl2 showed a dependency on the decontamination agents. We found that low-concentration aqueous acid solutions (e.g., 3% citric acid) showed a considerably enhanced efficiency compared to a 1% soap solution.