Comment on "Diluted concentrations of methamphetamine in surface water induce behavior disorder, transgenerational toxicity, and ecosystem-level consequences of fish" by Wang et al. [Water Research 184 (2020) 116-164].

Abstract The article presented by Wang et al. (2020) intends to elucidate the possible ecological effects of low (0.05–25 μg L−1) and higher (100 μg L−1) concentrations of methamphetamine on adult Oryzias latipes through a battery of assays, including histopathology. However, we found several mistakes and inaccuracies in the findings by means of this method. Given the increasing research effort in the field, the authors’ paper may become highly influential in future toxicological research. Despite the authors’ undoubted effort invested in their experiment, they did not employ standardized methods for histopathological assessment in the key laboratory experiment presented in their paper.