Within the CARACAS project, seven scientific topic groups have been set up to address specific aspects of Contaminated Land Risk Assessment. CARACAS participants contribute with their professional expertise to one or more of these Topic Groups.
Human Toxicology: focuses on issues such as appropriateness of primary toxicology data (exposure conditions, mode of delivery, chemical form); extrapolation from high to low doses and from animal to man; mechanisms of toxicity; exposure to mixtures; and bioavailability of contaminants in a soil matrix.
Ecological risk assessment: work involves characterising exposure and effects in various organisms and biological systems, including issues of bioconcentration, bioaccumulation and biomagnification. There are particular problems in interpreting multispecies exposure to mixtures of components, not all of them known or well characterised.
Fate and Transport of Contaminants: concerned with many issues relevant to removal, attenuation, phase transfer and bioavailability of contaminants, especially in complex mixtures. Processes include speciation, bio- and photo-degradation, plant uptake, sorption/desorption, dissolution, diffusion and volatilisation.
Site Investigation/Analysis: concerned with reviewing national approaches to sampling and analysis, and identifying the most crucial parameters for risk assessment. It seeks to make recommendations on data quality needs and good scientific practice to ensure appropriate statistically valid, and cost effective data.
Models: reviews the models available in the contaminated land risk assessment, including priority setting models and exposure/risk assessment models. Models are classified according to purpose of application, targets of concern, scientific basis and use status. An important area is to improve the validation and applicability of models.
Screening/Guideline Values: role of screening/guideline values, and the scientific and policy basis for them. The Group will compare and contrast different soil policy approaches, and the role of guideline values in soil management frameworks. Various protocols for deriving these values have been examined including basic assumptions and methodological aspects.
Methods for Risk Assessment: reviews and makes recommendations on methods to integrate the basic elements of risk assessment such as soil, sediment and groundwater sampling, exposure modelling and measurement, effects assessment and risk evaluation.