Exploring the use of species sensitivity distributions to define protective limits for the use of organic wastes as soil amendments.

Using organic wastes as soil amendments can be an important measure to improve soil quality and reduce waste accumulation and landfilling. However, their potential contaminant loads, can be a source of environmental concern. Consequently, legislation has been developed to regulate the use of these wastes in agricultural soils but only considers chemical parameters which are insufficient to establish their level of environmental risk. A possible solution is the use of Species sensitivity distributions (SSDs) to incorporate ecotoxicological data from test batteries in legislation. In this study, different hazardous concentrations (HC5 and HC50) were determined using ecotoxicological data (EC10 and EC50) for five different wastes. Results demonstrate that, as expected, current legislative thresholds do not translate to environmental risk/protection and that SSDs may be an important tool allowing the simple inclusion and interpretation of ecotoxicological data from test batteries in legislation. On the other hand, SSDs must be used with caution as there are still doubts on their actual risk and what estimates provide adequate protection. For instance, HC50EC10 values are not recommended and overlap with the more conservative HC5EC50 highlighting that using lower effect concentrations may not always provide the most protective approach. Also, hazardous concentrations need to be calibrated at the field or semi-field level, to verify environmental protection in different soils/environments and the adequacy of standard test organisms. This article is protected by copyright. All rights reserved.