Abstract:

In 2021, over 1 million fish were used for research, testing, and teaching in Canada alone representing 33.9% of all reported animal use (CCAC, 2022). Many of these fish were used in compliance with the Fisheries Act to determine the toxicity of industrial and municipal effluent in accordance with the EPS1/RM13 test method, which exposes fish to effluent for 96 hours. Recently, the Government of Canada stated its intent to amend the Canadian Environmental Protection Act to reduce reliance on vertebrates in toxicity testing; however, despite global efforts to replace, reduce, and refine animal use in science, few alternatives have been accepted as regulatory tests. One new approach that shows promise is the OECD 249 test that uses a fish gill cell line (RTgill-W1) to evaluate toxicity. This test method has been standardized and validated for testing chemicals (OECD, 2021), but not for effluents, as the complex composition of industrial effluents could allow for matrix effects that increase or reduce toxicity. The current research aims to evaluate if the new in vitro test method (OECD 249) is a suitable surrogate for the in vivo test method (EPS1/RM13) currently used to assess effluent toxicity. Specifically, the proposed research will investigate matrix interactions and assess the suitability of the OECD 249 to replace, reduce, and refine animal use in effluent testing. This work has the potential to decrease animal usage in regulatory toxicity testing and advance the use of new approach methods in regulatory frameworks.