High-resolution mass spectrometry is advantageous for monitoring physiological impacts and contaminant biotransformation products in fish exposed to complex wastewater effluent. We evaluated this technique using skin mucus from male and female fathead minnows (Pimephales promelas) exposed to control water or treated wastewater effluent at 5%, 20%, and 100% levels for 21 d, using an onsite, flow-through system providing real-time exposure. Both sex-specific and non-sex-specific responses were observed in the mucus metabolome, the latter suggesting the induction of general compensatory pathways for xenobiotic exposures. Altogether, 85 statistically significant treatment-dependent metabolite changes were observed and 30 of those annotated with probable structures. The mummichog software package was used to elucidate impacted biochemical pathways and enhance metabolite annotation. Partial least squares regression models revealed relationships between the mucus metabolomes and upregulated hepatic mRNA transcripts reported previously for these same fish. These regression models suggest that mucus metabolomic changes reflected, in part, processes by which the fish biotransformed xenobiotics in the effluent. Further, we detected a phase II transformation product of bisphenol A in the skin mucus of male fish. Collectively, these findings demonstrate the utility of mucus as a minimally invasive matrix for simultaneously assessing exposures and effects of real-world mixtures of contaminants. This dataset is associated with the following publication: Mosley, J., D. Ekman, J.E. Cavallin, D. Villeneuve, G. Ankley, and T. Collette. High‐resolution mass spectrometry of skin mucus for monitoring physiological impacts and contaminant biotransformation products in fathead minnows exposed to wastewater effluent. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 37(3): 788-796, (2018).

Public versions of EFSA DAR's - metabolism study summaries for the pesticides; Fluazinam, Halauxifen-methyl, Kresoxim-methyl, Mandestrobin, Tolclofos-methyl in fish (bluegill or rainbow trout), rat, and goat. This dataset is associated with the following publication: Kolanczyk, R., J. Serrano, M. Tapper, and P. Schmieder. A comparison of fish pesticide metabolic pathways with those of the rat and goat. REGULATORY TOXICOLOGY AND PHARMACOLOGY. Elsevier Science Ltd, New York, NY, USA, 94: 124-143, (2018).

Organic ultraviolet filters (UVFs; also known as sunscreen agents) used in personal care and consumer products can enter the aquatic environment via wastewater treatment plant effluents or by loss from skin during swimming and other recreational activities. Some UVFs are hydrophobic (log Kow > 4) which has led to concern that they may bioaccumulate in aquatic organisms. The purpose of this study was to investigate the bioaccumulation and biotransformation of two widely-used UVFs, 2-ethylhexyl-4-methoxycinnamate (EHMC) and octocrylene (OCT) in rainbow trout exposed via the diet. EHMC and OCT were significantly metabolized by trout and this metabolism substantially reduced bioaccumulation relative to levels observed for a set of poorly transformed chemicals having similar log Kow values. Derived bioconcentration factors (BCFs) and biomagnification factors (BMFs) for both UVFs were well below established bioaccumulation criteria, suggesting that EHMC and OCT are unlikely to pose a bioaccumulation hazard in trout. This research substantially increases existing knowledge concerning the fate and effects of UVFs in the environment. This dataset is associated with the following publication: Saunders, L., A. Hoffman, J. Nichols, and F. Gobas. Dietary bioaccumulation and biotransformation of hydrophobic organic sunscreen agents in rainbow trout. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 39(3): 574-586, (2020).

The purpose of is this study was to evaluate the potential for biotransformation in the gastrointestinal tissues (GIT) of fish to impact chemical bioaccumulation. In vitro biotransformation of two polycyclic aromatic hydrocarbons, pyrene (PYR) and benzo[a]pyrene (BAP), and two organic sunscreen agents, 2-ethylhexyl-4-methoxycinnamate (EHMC) and octocrylene (OCT), was measured using S9 fractions isolated from liver tissue and tissues of the upper GIT in rainbow trout. For PYR, BAP, and EHMC, activity was substantially higher in liver S9 fractions than in GIT S9 fractions. For OCT, activity was highest in GIT S9 fractions. An existing in vitro-in vivo extrapolation (IVIVE) model for fish, which yields a whole-animal biotransformation rate constant (kMET), was expanded to consider biotransformation in the GIT. The kMET values obtained using measured rates of in vitro activity (liver and GIT) were in good agreement with kMET values measured in controlled in vivo experiments, providing strong support for the IVIVE approach. Moreover, inclusion of GIT activity into the model prediction for OCT resulted in much better agreement with the empirical kMET estimate than was obtained using a ‘liver only’ model. These findings suggest that current ‘liver only’ approaches to IVIVE modeling may underestimate in vivo whole-animal biotransformation rates for chemicals that undergo substantial biotransformation in the GIT. Thus, failure to consider biotransformation in the GIT may lead to overestimation of true levels of bioaccumulation. This dataset is associated with the following publication: Saunders, L., P. Fitzsimmons, J. Nichols, and F. Gobas. In vitro-in vivo extrapolation of hepatic and gastrointestinal biotrasnformation rates of hydrophobic chemicals in rainbow trout. AQUATIC TOXICOLOGY. Elsevier Science Ltd, New York, NY, USA, 228: 1-12, (2020).