The effect of emerging pollutants in the North Sea on fish growth : an in silico-in vitro approach

Environmental risk assessment is of extreme importance to assure a safe, balanced and sustainable use of chemicals, while playing a key role in environmental regulation. However, it currently relies on ethically controversial, expensive and time-costly methods and experiments (e.g. animal testing). Moreover, quantification of chemical toxicity is commonly based on external concentrations in water, soil or air, even though it is the internal concentration in the organism that gives raise to the biological effect. Recently, a combination of in vitro and in silico has been put forward as a viable alternative to the conventional in vivo testing. In this study, we have applied this concept to emerging pollutants detected in the North Sea, particularly pharmaceuticals and pesticides. We assessed the effect of these chemicals on growth impairment in fish through in silico methods, using predicted internal concentrations of these chemicals, based on environmental concentrations. In particular, we exposed gill cells of rainbow trout (Oncorhynchus mykiss), RTgill-W1 cell line, to the predicted internal concentrations of each chemical and then used the in vitro cell growth to predict in vivo growth. It is our believe that the adopted methodology allows the tackling of the previously described issues related to chemical risk assessment and encourages a shift of the current paradigm