Surfactants in sludge-amended soil

Environmental risk assessment (ERA) is the most complete approach to deter mining the environmental acceptability of existing surfactants. The major surfactants have been recently evaluated for the aquatic environment. The conclusion was that the risk they pose to this environmental compartment is very low, PEC/PNEC (Predicted Environmental Concentration/Predicted Bo-Effect Concentration) For the terrestrial environment, even if there is no reason ro believe on the basis of available evidence that surfactants represent any hazard, there is a potential concern over the lack of toxicity, data. In addition there is a need to develop an objective approach for surfactants which allows a rational basis ibr setting up quality standards fbr sludge intended for agricultural use and for soils receiving such sludge. In this presentation, the known practice of sludge application in agriculture is reviewed and the research activities in progress in this area in Denmark are briefly summarized. By way of example, a preliminary terrestrial risk assessment (TRA) for linear alkylbenzene sulfonate (LAS), bused on rite presently available literature, is reported.