The Paardenmarkt is a dumpsite from World War I (WW I) located in the Belgian part of the North Sea in which approximately 35 tons of conventional and chemical munition are buried. Given the insufficient data on the impact of munition-related chemicals on environmental and human health, it is not possible to reliably assess the state of the dumpsite. The current project aims at addressing some of the current knowledge gaps, with particular focus on the toxic potential of contaminated sediment on the marine biota, in order to support risk assessment and management of munition pollution in the Paardenmarkt. For that, samples collected from the dumpsite will be used to assess the acute and chronic toxicity of the contaminated sediment in different species of marine organisms with endpoints comprising larval development, reproduction, population growth rate as well as geno- and cytotoxicity, biochemical biomarkers and bioenergetics parameters, hence providing a realistic overview on the impact of munition pollution on the marine environment. Additionally, the bioaccumulation potential of Clark I, a chemical frequently detected in munition dumpsites, will be assessed in mussels thus shading light on the potential human exposure to contaminated seafood.