Prediction of algal bioaccumulation and uptake rate of nine organic compounds by ten physicochemical properties

Many quantitative structure-activity relationships describe steady-state levels of accumulation of organic contaminants in aquatic organisms, but few treat the dynamics by which these levels are achieved. This paper extends this approach by developing relations to describe the time course of uptake for different organic compounds. The instantaneous rates of uptake and the bioconcentration factors (BCF) of nine organic compounds were determined by following the bioaccumulation of radioactively labeled compounds in the green alga Selenastrum capricornutum. When all nine compounds are used in regression, capacity ratio and the octanol/water partition coefficient predict BCF equally well. However, if the hydrocarbons alone are considered, the capacity ratio predicts BCF most effectively. The uptake rate, which could only be measured effectively for five compounds, is best predicted by the connectivity index. These two regression were effective in reconstructing the original experiment; they may also be effective at predicting the time course of contaminant bioaccumulation