On the aquatic toxicity of diverse chemicals: Development of novel in silico models tow ards selected aquatic organisms under the framework of reach regulation

Abstract

Environmental hazard and risk assessment of chemicals are crucial for aquatic species within the direction of the European Regulation on the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH). In consideration of ethical concerns, animal welfare and sustainability, as well as the need for aquatic toxicity data, in silico models, such as validated quantitative structure-toxicity relationships (QSTRs), are of great importance. In the present study, an activity-independent rational approach towards selecting an optimal geometry optimization method for improved QSTR modeling was proposed for the first time. Different QSTR and interspecies models towards three representative aquatic species (algae, fish, and planarian) were developed using the rational approach recommended. QSTR models on the prediction of cytotoxicity to rainbow trout liver cell line (RTL-W1), toxicity to Dugesia japonica, and an interspecies quantitative toxicity relationship between Daphnia magna and D. japonica were reported for the first time. The presented QSTR models have contributed to the literature by providing notable prediction coverage for environmentally significant chemicals, such as contaminants of emerging concern and high production volume chemicals. Furthermore, the first predicted aquatic toxicity and cytotoxicity data were provided for a great majority of the chemicals addressed in “The List of Chemicals with no Ecotoxicological Data” announced by the Scientific and Technological Research Council of Turkey (TÜBİTAK). The developed models are promising as potential tools in toxicity assessment, screening and prioritization of chemicals in a scientific and regulatory frame.