Dumped munitions : Effects, metabolism and detection of explosive compounds and chemical warfare agent-related chemicals in fish from the Baltic Sea
Dumped munitions in the marine environment, a legacy mainly originating from World Wars I and II, constitute a contemporary environmental problem affecting marine biota, maritime infrastructure and economy, and humans. The disposal mainly took place in the aftermath of the war as legal practice until the 1970s and environmental consequences played a minor role in this situation. Nowadays, due to the permanent exposure of the munition shells to seawater, many shells are corroded and the corrosion will continue in the future. Where shells are broken, the compounds they contain leak into the marine environment leading to exposure of marine organisms, including fish. This risk posed by dumped munitions exists at various locations around the world, often in coastal waters. With hundreds of thousands of tons of dumped munitions, both conventional explosives and chemical warfare agents (CWAs), the Baltic Sea is an important area of investigation. Conventional munitions contain organic explosive compounds such as the nitroaromatic 2,4,6-trinitrotoluene (TNT) and the nitramines hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). CWAs are part of chemical weapons (CW), which were also dumped on large scale in the Baltic Sea and often contain sulphur mustard (Mustard Gas) or arsenic-based warfare agents like Clark I and II and Adamsite. Both compounds from conventional munitions and chemical warfare agents are known to cause toxic effects in humans and wildlife. However, toxicity studies of nitroaromatic compounds in fish are mainly limited to their acute effects and the toxicity of CWAs in fish is completely unknown. To date, information on the distribution and condition of munitions is scarce. Most of the countries affected lack coordinated action by political stakeholders to develop a management concept for the future. In order to provide solutions for these unsolved challenges, the international DAIMON project (Decision Aid for Marine Munitions), involving research institutions from countries bordering the Baltic Sea, aimed to establish a scientific basis for decisions on the future management of dumped munitions in the sea. This also includes improving our understanding of the effects and fate of munition compounds in fish, which are an essential part of the marine environment. This thesis was carried out in the framework of the DAIMON project and focused mainly on TNT as a frequently occuring component of conventional munitions. It investigated: 1) the genotoxicity of nitroaromatic compounds in fish, 2) the metabolism of munition compounds in fish liver and 3) the detection of munition compounds in fish from the Baltic Sea.