This project demonstrated the feasibility of in-vitro biotransformation testing and delivered a protocol for an in-vitro biotransformation assay for studying the rate at which fish can metabolise surfactants. The potential of the in-vitro biotransformation rates for use in predicting the bioconcentration behaviour of surfactants has since been recognised by SETAC and by HESI. Both organisations followed up on the initial ERASM work to investigate the use of in-vitro biotransformation rates in predicting the bioconcentration behaviour of surfactants.
Studies on the bioaccumulation of linear alkylbenzene sulphonate [LAS] and alcohol ethoxylates [AE] surfactants (Tolls, 1998) have demonstrated that biotransformation is an important mechanism by which fish can reduce the surfactant concentration in their bodies. The rate of biotransformation can be studied in in-vitro biotransformation experiments with fish-derived material, e.g. liver cells and homogenates. However, limited experience is available in such experiments with surfactants. Presently, it is not yet clear if this approach is feasible for this type of substances, when only conventional analytical methods are available, and if it can be used for an evaluation of the bioconcentration of surfactants in fish.
Outcome of research
The project delivered a protocol for an in-vitro biotransformation assay, in-vitro biotransformation rates for AEs and LAS surfactants in rainbow trout and in carp. The in-vitro biotransformation rates appear to be slightly dependent on the fish species and they differ to some degree between the surfactants.