The overall aim of the project is to provide methods to determine bioavailable concentrations of contaminants in soils and sediments so that they may be compared to quality criteria as part of a risk assessment. The major objectives of the project are:
To study the sorption and bioavailability of organic contaminants by both experimental methods and by molecular modelling.
To develop kinetic models and structure activity relationships which can be used to predict the bioavailability of contaminants in soils and sediments.
To use the results of the above research to develop methods to readily measure the bioavailability of soil and sediment contamination.
To develop protocols for the risk assessment of organic contaminants in soils and sediments based on their actual bioavailability.
Contamination of soils and sediments by organic chemicals is a major threat to the environmental quality of freshwater and groundwater resources. At present, assessment of the risks of soil and sediment contamination is based on theassumption of bulk organic carbon-based equilibrium partitioning. However, it isgenerally accepted in scientific circles that this assumption is inappropriateand can lead to an overestimation of the risks of soil and sedimentcontamination. This project will investigate the mechanistic basis for theformation of different sorbed fractions of contaminants in soils and sediments and the bioavailability of these fractions. Methods will be developed to easily determine bioavailable fractions of contaminants in relation to their sorptionkinetics. These results will be exploited to develop protocols for the risk assessment of sorbed contaminants in soils and sediments.