Validation of the EAU Pharmaceuticals Workbook: Predicted Vs. Measured Environmental Concentrations

The EAU pharmaceutical workbook can be used to calculate environmental concentrations of pharmaceutical ingredients. Two model scenarios are considered, one for consumer use and another for manufacture. For 48 pharmaceutical substances, the average predicted environmental concentration (PEC) from the model was compared to average measured environmental concentrations (MEC) in wastewater effluents. A difference ratio with a value of less than |10| represents a PEC within 1 magnitude of the MEC, while a difference ratio with a value of less than |100| represents a PEC within 2 magnitudes of the MEC. Results showed that 54.2 - 62.5% of predictions are within 1 magnitude of measured environmental concentrations, and 89.6 - 93.8% of predictions are within 2 magnitudes of measured environmental concentrations. The consumer scenario gave PEC values closer to the MECs that the manufacture scenario.