title: Estimating the predicted environmental concentration of the residues of veterinary medicines: should uncertainty and variability be ignored?
abstract: European directives require that all veterinary medicines be assessed to determine the harmful effects that their use may have on the environment. Fundamental to this assessment is the calculation of the predicted environmental concentration (PEC), which is dependent on the type of drug, its associated treatment characteristics, and the route by which residues enter the environment. Deterministic models for the calculation of the PEC have previously been presented. In this article, the inclusion of variability and uncertainty within such models is introduced. In particular, models for the calculation of the PEC for residues excreted directly onto pasture by grazing animals are considered and comparison of deterministic and stochastic results suggest that uncertainty and variability cannot be ignored.
authors.affiliation: Department of Risk Research, Veterinary Laboratories Agency Weybridge, New Haw, Addlestone, Surrey KT15 3NB, UK. louise@stams.strath.ac.uk
authors.forename: Louise A
authors.initials: LA
authors.lastname: Kelly
authors.forename: Mike A
authors.initials: MA
authors.lastname: Taylor
authors.forename: Marion J A
authors.initials: MJ
authors.lastname: Wooldridge
mesh_terms: D000818:Animals; D004785:Environmental Pollutants / Q000032:analysis* / Q000633:toxicity*; D005062:European Union; D005243:Feces / Q000737:chemistry; D006801:Humans; D008954:Models, Biological; D018570:Risk Assessment; D012449:Safety; D012989:Soil Pollutants / Q000032:analysis / Q000633:toxicity; D013269:Stochastic Processes; D019155:Veterinary Drugs / Q000032:analysis* / Q000633:toxicity*
chemical_list: D004785:Environmental Pollutants; D012989:Soil Pollutants; D019155:Veterinary Drugs