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).

Detailed data and analysis supporting manuscript Dietary uptake of highly hydrophobic chemicals by rainbow trout. This dataset is associated with the following publication: Burkhard, L., T. Lahren, K. Hanson, A. Kasparek, and D. Mount. Dietary Uptake of Highly Hydrophobic Chemicals by Rainbow Trout (Oncorhynchus Mykiss). ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY. Springer, New York, NY, USA, 85(4): 390-403, (2023).

Results of acute and chronic exposure of rainbow trout and warm water fish to metals and other toxicants.

Results of acute and chronic exposure of rainbow trout and warm water fish to metals and other toxicants.

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).

Among the data required by the U.S. Food and Drug Administration (FDA) for approval of an aquaculture drug are the data that characterize the depletion of a drugs marker residue from the edible fillet tissue of fish after exposure. Eugenol is the marker residue for AQUI-S 20E, a product proposed for use as a sedative for fish.Rainbow trout (Onchorynchus mykiss; a representative cold water fish species) was exposed to AQUI-S 20E in water at a temperature of 9 C, a temperature that is representative of the lower range of temperatures where rainbow trout would be sedated. Eighty fish were exposed to a nominal AQUI-S 20E concentration of 100 mg/L for 60 min. Groups of 16 fish were sampled immediately after 60 min of exposure (the 0 min sample group), then at 15, 30, 90, and 150 min after the fish were transferred to fresh, flowing water. Skin-on fillets from each fish were analyzed for eugenol concentrations by using a FDA approved method for determining eugenol concentrations in fish fillet tissue. The method involved extracting eugenol from the tissue with acetonitrile, recovering eugenol from the tissue extract by using solid phase extraction techniques, and determining eugenol concentrations in the final extract by using high pressure liquid chromatography with absorbance detection techniques.Results indicated that maximum eugenol concentrations in the fillet tissue were measured immediately after the exposure (mean, 47.5 g/g). Eugenol concentrations decreased to 1.9 g/g by 150 min after the fish were transferred to fresh, flowing water. The depletion of eugenol from the fillet tissue was rapid (t1/2 = 31.7 min).

Among the data required by the U.S. Food and Drug Administration (FDA) for approval of an aquaculture drug are the data that characterize the depletion of a drugs marker residue from the edible fillet tissue of fish after exposure. Eugenol is the marker residue for AQUI-S 20E, a product proposed for use as a sedative for fish.Rainbow trout (Onchorynchus mykiss; a representative cold water fish species) was exposed to AQUI-S 20E in water at a temperature of 9 C, a temperature that is representative of the lower range of temperatures where rainbow trout would be sedated. Eighty fish were exposed to a nominal AQUI-S 20E concentration of 100 mg/L for 60 min. Groups of 16 fish were sampled immediately after 60 min of exposure (the 0 min sample group), then at 15, 30, 90, and 150 min after the fish were transferred to fresh, flowing water. Skin-on fillets from each fish were analyzed for eugenol concentrations by using a FDA approved method for determining eugenol concentrations in fish fillet tissue. The method involved extracting eugenol from the tissue with acetonitrile, recovering eugenol from the tissue extract by using solid phase extraction techniques, and determining eugenol concentrations in the final extract by using high pressure liquid chromatography with absorbance detection techniques.Results indicated that maximum eugenol concentrations in the fillet tissue were measured immediately after the exposure (mean, 47.5 g/g). Eugenol concentrations decreased to 1.9 g/g by 150 min after the fish were transferred to fresh, flowing water. The depletion of eugenol from the fillet tissue was rapid (t1/2 = 31.7 min).

This ScienceHub entry was developed for the published paper: Consoer et al., 2016, Toxicokinetics of perfluorooctane sulfonate in rainow trout (Oncorhynchus mykiss), Environ. Toxicol. Chem. 35:717-727. Individual rainbow trout were exposed to PFOS by bolus injection (elimination studies) or by adding PFOS to incoming water (branchial uptake studies). The trout were fitted with indwelling catheters and urinary cannulae to permit periodic collection of blood and urine. Additional sampling was conducted to evaluate PFOS uptake from and elimination to respired water. Data obtained from each fish was evaluated using a clearance-volume pharmacokinetic model. Modeled kinetic parameters were then averaged to develop summary statistics which were used as a basis for interpreting modeled results and making comparisons to a previous study of rainbow trout exposed to perfluorooctanoate (PFOA; Consoer et al., 2014, Aquat. Toxicol. 156:65-73). The results of this study, combined with that of the previous PFOA study, suggest that PFOA is a substrate for renal transporters in fish while glomerular filtration alone may be sufficient to explain the observed renal elimination of PFOS. These findings demonstrate that models developed to predict the bioaccumulation of perfluoroalkyl acids by fish must account for differences in renal clearance of individual compounds. This dataset is associated with the following publication: Consoer, D., A. Hoffman , P. Fitzsimmons , P. Kosian , and J. Nichols. Toxicokinetics of perfluorooctane sulfonate in rainbow trout (Oncorhynchus mykiss). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 35(3): 717-727, (2016).

This ScienceHub entry was developed for the published paper: Consoer et al., 2016, Toxicokinetics of perfluorooctane sulfonate in rainow trout (Oncorhynchus mykiss), Environ. Toxicol. Chem. 35:717-727. Individual rainbow trout were exposed to PFOS by bolus injection (elimination studies) or by adding PFOS to incoming water (branchial uptake studies). The trout were fitted with indwelling catheters and urinary cannulae to permit periodic collection of blood and urine. Additional sampling was conducted to evaluate PFOS uptake from and elimination to respired water. Data obtained from each fish was evaluated using a clearance-volume pharmacokinetic model. Modeled kinetic parameters were then averaged to develop summary statistics which were used as a basis for interpreting modeled results and making comparisons to a previous study of rainbow trout exposed to perfluorooctanoate (PFOA; Consoer et al., 2014, Aquat. Toxicol. 156:65-73). The results of this study, combined with that of the previous PFOA study, suggest that PFOA is a substrate for renal transporters in fish while glomerular filtration alone may be sufficient to explain the observed renal elimination of PFOS. These findings demonstrate that models developed to predict the bioaccumulation of perfluoroalkyl acids by fish must account for differences in renal clearance of individual compounds. This dataset is associated with the following publication: Consoer, D., A. Hoffman , P. Fitzsimmons , P. Kosian , and J. Nichols. Toxicokinetics of perfluorooctane sulfonate in rainbow trout (Oncorhynchus mykiss). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 35(3): 717-727, (2016).