Occurrence, fate and environmental risk assessment of pharmaceutical compounds in soils amended with organic wastes

One of the most common ways of getting rid of sewage sludge is land spreading on agricultural fields as a source of nutrients and organic matter. However, sewage sludge may be contaminated with pharmaceuticals and can represent a cause of environmental contamination. The objectives of this study was (i) to determine the occurrence and the fate of pharmaceuticals such as antibiotics belonging to different classes: antibiotics (sulfadiazine, sulfamethoxazole, sulfamethoxypyridazine, ciprofloxacin, norfloxacin, tylosin, trimethoprim), anti-inflammatories (diclofenac) and anticonvulsants (carbamazepine) in the soil after spreading stabilized sludge (composted, limed and digested) and solid digestat, (ii) to evaluate agronomic benefits and (iii) to determine the potential ecotoxicological consequences of pharmaceutical compounds on the environment using a risk quotient approach. For this purpose, four different types of sludge samples, coming from the same treatment plant but submitted to different stabilization processes, were incorporated into three soils with different physicochemical characteristics and pedogenetic factors. The obtained results highlighted that the sludge treatments have a great influence on sludge contamination. Once applied onto the soil, the agronomic benefits will depend on the soil's properties as well as the sludge's characteristics. The risks concerning the ecotoxicity of pharmaceuticals, found in the sludge, are low but not insignificant.