The exposure assessment for veterinary medicinal products

The proposed methodology for the assessment of the environmental risks of the use of veterinary medicinal products is the hazard quotient approach. This article will elaborate on the exposure assessment with exposure models adapted to the Dutch agricultural situation. Based on the exposure assessment, decisions are made on the acceptability of the environmental risk of a product. Therefore, regulatory authorities have to be careful in choosing exposure scenarios. It will be shown that simple alterations of general models with an eye for common agricultural practice change predicted exposure concentrations by a factor of 2–40. In addition, the current proposals for effect assessment are too diverse, and the triggers that lead to further extensive testing are either useless, or at the least inconsistent with each other. An interdisciplinary approach using knowledge of veterinary and agricultural practice, risk management, and environmental toxicology and chemistry, is needed to determine relevant exposure scenarios.