Estimation methods for bioaccumulation in risk assessment of organic chemicals.

The methodology for estimating bioaccumulation of organic chemicals is evaluated. This study is limited to three types of organisms: fish, earthworms and plants (leaf crops, root crops and grass). We propose a simple mechanistic model for estimating BCFs which performs well against measured data. To evaluate the dynamics of bioaccumulation, simple one-compartment models are selected and parameterised. For specific chemical properties, the concentration in the organism reacts slowly to changes in the environmental concentration. This does not generally affect the estimation of long-term average concentrations which are relevant for risk assessment.