Sustainable use of Veterinary Pharmaceuticals on the territory and groundwater resources quality

Use of Veterinary Pharmaceuticals (VPs) is more and more increasing. Presence of their residues is an emerging threat for the quality of water resources in both groundwater and surface water systems. The main route of entry into the environment is the disposal of contaminated manure in or into the ground [1][2]. Once released to land, active ingredients and their metabolites may enter environmental matrices following usual patterns: via run off to surface water or leaching to groundwater. Leaching is influenced by physical and chemical properties as well as on the climate conditions and soil characteristics of the site that receives the manure [3]. Analogously to the evolution of the EU legislation on pesticides there is an increasing need to develop tools for managing and reduce the risk for the groundwater in the context of the territory, in order to increase the “sustainable use of veterinary pharmaceuticals” in livestock production. Several problems arise when a risk assessor need to identify the environmental fate of a VP: identification of real administration doses in each livestock, identification of real distribution amount of manure in fields, calculation of the active ingredient dose in soil from the manure applied and evaluation of active ingredient transport in groundwater. This paper proposes a methodology of evaluation of the presence of VPs in the groundwater of Lombardy region (North of Italy). It relies on manure distribution data from a constantly updated regional database [4]. A comparison with the methodology suggested by international guidelines which refers to default values underlines some important differences in the results.