Evidence of environmental threat caused by sea-dumped chemical warfare agents: Exposure status of hagfish in the skagerrak strait.

Ammunitions containing toxic chemical warfare agents (CWAs) that were seized from Germany at the end of World War II were disposed mainly by sea-dumping in the Skagerrak Strait and the Baltic Sea. In an area located 25 nautical miles south-east of Arendal, Norway, several ships carrying cargo of chemical munitions were scuttled. Previous investigations have revealed that CWAs are leaking from containers and munitions into surrounding sediments in the area, raising concerns of bioaccumulation of these chemicals in marine biota. In this study, Hagfish (Myxine glutinosa) was used as a model animal to investigate uptake of phenylarsenic CWAs by marine biota caught from the dumping area outside Arendal. Two laboratories analysed hagfish samples for primary degradation products of the phenylarsenic chemicals Clark I/II, namely diphenylarsinic acid and triphenylarsine oxide which have been previously found in sediment samples from the same area. The investigation showed that studied chemicals, originating from leaking munitions, are bioaccumulating in hagfish. These results support earlier findings of bioaccumulation of CWA-related phenylarsenic chemicals in different marine biota species living in the vicinity of dumping areas with increasing concern on environmental impacts caused by marine munitions. In addition, a novel biotransformation product of Clark I/II, methyldiphenylarsine oxide (MDPAO) was detected in studied fish samples for the first time. Based on findings reported in this study, biotransformation products of phenylarsenic CWAs should be considered as target chemicals in future evaluations of CWA exposure in marine biota. As the information on bioaccumulation and biological effects of CWAs in marine species are narrow, results gained in this study are essential for risk assessment related to marine munitions, as well as for future monitoring campaigns.