Acute toxicity of organoarsenic chemical warfare agents to Danio rerio embryos

Wojciech Wilczynski; Tomasz Brzeziński; Piotr Maszczyk; Antoni Ludew; Michał J Czub; Daniel Dziedzic; Jakub Nawala; Stanislaw Popiel; Jacek Beldowski; Hans Sanderson; Monika Radlinska

doi:10.1016/j.ecoenv.2023.115116

Acute toxicity of organoarsenic chemical warfare agents to Danio rerio embryos

Ecotoxicol Environ Saf. 2023 Jun 12:262:115116. doi: 10.1016/j.ecoenv.2023.115116. Online ahead of print.

Authors

Affiliations

¹ Department of Environmental Microbiology and Biotechnology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Poland; Department of Hydrobiology, Institute of Functional Biology and Ecology, Faculty of Biology, University of Warsaw, Poland. Electronic address: wk.wilczynski@gmail.com.
² Department of Hydrobiology, Institute of Functional Biology and Ecology, Faculty of Biology, University of Warsaw, Poland.
³ Medical University of Warsaw, Poland.
⁴ Department of Hydrobiology, Institute of Functional Biology and Ecology, Faculty of Biology, University of Warsaw, Poland; Institute of Oceanology, Polish Academy of Sciences, Poland; Department of Environmental Science, Aarhus University, Roskilde, Denmark.
⁵ Faculty of Advanced Technologies and Chemistry, Military University of Technology, Warsaw, Poland.
⁶ Institute of Oceanology, Polish Academy of Sciences, Poland.
⁷ Department of Environmental Science, Aarhus University, Roskilde, Denmark.
⁸ Department of Environmental Microbiology and Biotechnology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Poland.

PMID: 37315364
DOI: 10.1016/j.ecoenv.2023.115116

Abstract

During the 20th century, thousands of tons of munitions containing organoarsenic chemical warfare agents (CWAs) were dumped into oceans, seas and inland waters around the world. As a result, organoarsenic CWAs continue to leak from corroding munitions into sediments and their environmental concentrations are expected to peak over the next few decades. There remains, however, a lack of knowledge about their potential toxicity to aquatic vertebrates, such as fish. The aim of this study was to fill in this gap in research, by investigating the acute toxicity of organoarsenic CWAs on fish embryos, using the model species, Danio rerio. To estimate the acute toxicity thresholds of organoarsenic CWAs (Clark I, Adamsite, PDCA), a CWA-related compound (TPA), as well as four organoarsenic CWA degradation products (Clark I[ox], Adamsite[ox], PDCA[ox], TPA[ox]), standardized tests were performed following the OECD no. 236 Fish Embryo Acute Toxicity Test guidelines. Additionally, the detoxification response in D. rerio embryos was investigated by analysing the mRNA expression of five genes encoding antioxidant enzymes (CAT, SOD, GPx, GR and GST). During the 96 h of exposure, organoarsenic CWAs induced lethal effects in D. rerio embryos at very low concentrations (classified as 1st category pollutants according to GHS categorization), and were therefore deemed to be serious environmental hazards. Although TPA and the four CWA degradation products caused no acute toxicity even at their maximum solubility, the transcription of antioxidant-related genes was altered upon exposure to these compounds, indicating the need for further testing for chronic toxicity. Incorporating the results of this study into ecological risk assessments will provide a more accurate prediction of the environmental hazards posed by CWA-related organoarsenicals.

Keywords: Adamsite; Clark I; PDCA; Sea-dumped munitions; TPA; Zebrafish.