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(20-18) VetPec: a software simulation for estimation of residues of veterinary drugs in water. Long, Carol*,1, Tait, Alex1, 1 Veterinary Medicines Directorate, Addlestone, Surrey, UK ABSTRACT- Environmental risk assessment of veterinary medicines has been required in the European Union since 1993. Legislation requires this in two phases and guidelines are in place to assist in the preparation of the environmental assessment. Phase I evaluates the extent of environmental exposure and when this is low the assessment ends. When environmental exposure is significant assessment in Phase II is required. Products which are used for mass medication of housed animals, particularly pigs and poultry, tend to require a Phase II assessment which involves elucidation of the fate and effects in the environment. For housed animals the veterinary medicine enters soil when manure from treated animals is spread onto land. Until recently only the predicted environmental concentration (PEC) of the residue in soil could be estimated using a standard procedure and PEC values produced for various exposure scenarios. Suitable standardised techniques were not available for reliable and relevant estimation of the movement of residue to groundwater and to surface waters. However, a software simulation tool (VetPec) has been developed that enables the concentrations of residue of veterinary drugs in water to be estimated. VetPec calculates the PEC of veterinary medicines in soil, soil pore water, groundwater and surface water that arise from the spreading of manure. The speed with which a number of different scenarios can be modelled should result in a more probabilistic approach to the risk assessment. In the presentation the VetPec simulation will be described and the results obtained with VetPec for generic veterinary drugs will be compared to results from the more basic calculation methods. The differences will be discussed in relation to their impact on the environmental risk assessment. Key words: veterinary, environment, assessment, simulation |
