Department Environmental Toxicology

Predicting biotransformation and bioconcentration of organic chemicals in fish


Quantification of chemical toxicity continues to be based mainly on measurements of external exposure. Yet, in order to understand, interpret and extrapolate toxic effects, using internal concentrations of chemicals is more suitable. Though these can be measured, being able to predict them would be much more efficient and feasible. Predicting chemical internal concentrations accurately is, however, still challenging as biotransformation processes can strongly influence the extent to which chemicals accumulate in fish. For this reason, toxicokinetic models, which link in vitro biotransformation data to the whole organism bioconcentration of chemicals, have been developed. However, these models thus far are based on the assumption that biotransformation in the body solely occurs in fish liver. Since this is unlikely to be true, this assumption may result in underestimating the biotransformation of chemicals in fish. 
In our project we measure chemical biotransformation in rainbow trout cell lines of liver (RTL-W1), intestine (RTgut-GC) and gills (RTgill-W1). Acknowledging that the liver is the main site of biotransformation whereas gills are not, we assumed that the gill cell line can represent cells also from other richly perfused tissues. We distinguish the intestine and pyloric caeca from richly perfused tissues in order to account for biotransformation occurring in the intestine as an important environment - organism barrier. Biotransformation rates from all cell lines are then incorporated into the Physiologically Based Toxicokinetic (PBTK) model for rainbow trout in order to predict chemical bioconcentration in fish. 

This study has recently obtained additional funding from CEFIC-LRI (LRI-ECO34, project title: A tiered testing strategy for rapid estimation of bioaccumulation by a combined modelling - in vitro testing approach).

Latest publications

Stadnicka-Michalak J., Weiss F., Knöbel M., Schirmer K. (2014), Biotransformation in fish cell lines to predict bioconcentration in fish: a case study with benzo(a)pyrene, SETAC North America 35th Annual Meeting, Vancouver, Canada, 09.11-13.11.

Stadnicka, J.; Schirmer, K.; Ashauer, R. (2012) Predicting concentrations of organic chemicals in fish by using toxicokinetic models, Environmental Science and Technology, 46(6), 3273-3280, doi:10.1021/es2043728, Institutional Repository