Chemical warfare agents and their risk assessment in Daphnia magna and fish in the Baltic Sea – 15 years of measurements

• Published in: Journal of hazardous materials advances 2023-11, Vol.12, p.100386, Article 100386
• Main Authors: Fauser, Patrik, Czub, Michał J., Bełdowski, Jacek, Niemikoski, Hanna, Vanninen, Paula, Popiel, Stanisław, Nawała, Jakub, Dziedzic, Daniel, Sanderson, Hans
• Format: Article
• Language: English
• Subjects: assessment factors; biotransformation; organoarsenicals; sediment; Sulfur mustard
• ISSN: 2772-4166; 2772-4166
• DOI: 10.1016/j.hazadv.2023.100386

•Compilation and risk analysis of 872 data points on measurements of CWAs and their degradation products sampled from 2005 to 2019 in the Baltic Sea sediments.•When using chemical specific toxicological data (EC50 or NOEC) with assessment factors, 383 exceedances of risk for the sum of chemicals are found for Daphnia magna and fish.•When using Danish Environmental Quality Standard (DK EQS) values for arsenicals, which represent the marine environment, 25 exceedances of risk for the sum of chemicals are found.•The results underline the importance of obtaining more representative and accurate toxicological data in order to increase the accuracy of the risk estimates. The Baltic Sea is one of the world's largest brackish waters, it is drained through the Danish Straits into the Kattegat, and almost enclosed by nine countries. The Baltic Sea is one of the world's most polluted water bodies thus facing a wide range of environmental threats towards its water resources, such as fish stocks, and coastal environments and economics. Chemical warfare agents (CWAs) that were dumped following the Second World War are known to occur in intact or degraded states in sediments and are documented to affect benthic fauna and fish as well as having injured fishermen having accidentally caught lumps of CWAs in their nets. However, a thorough mapping of remaining CWAs and degradation products and an understanding of the environmental risks does not exist although more than 75 years have passed. This study compiles and analyzes published/peer-reviewed data, generated since 2005 in five selected comprehensive studies, on sediment measurements of known dumped CWAs and degradation products in the Baltic Sea. As a worst-case approach, sediment concentrations are transformed to concentrations in near-bottom water, which represents Predicted Environmental Concentrations (PECs) to marine biota. To investigate the accuracy and representativeness of toxicological values, which are fundamental in risk assessments, two cases are considered: Case 1 (specificity) uses toxicological data (EC50 or NOEC) for Daphnia magna and fish with applied assessment factors (AF) to derive Predicted No-Effect Concentrations (PNECs) for organoarsenical and non-arsenical CWAs; Case 2 (robustness) uses partly Danish Environmental Quality Standards (DK EQS) for arsenicals, and partly a Water Quality Criterion (WQC) for arsenicals, representing the marine environment. From 872 data points risk quotients (RQs=PEC