Environmental risk assessment of six human pharmaceuticals: Are the current environmental risk assessment procedures sufficient for the protection of the aquatic environment?

TLDR

The study investigates whether current European environmental risk assessment procedures adequately protect aquatic environments by compiling exposure and ecotoxicity data for six human pharmaceuticals. Using the two‑tiered European draft guideline, the authors compared measured and predicted environmental concentrations in French and German effluents and surface waters to predicted no‑effect concentrations derived from acute and chronic toxicity data, calculating PEC/PNEC ratios. All measured and predicted concentrations exceeded the 10‑ng/L threshold, revealing that carbamazepine and propranolol were incorrectly classified as low risk and underscoring the need for more appropriate ecotoxicity tests in the current assessment framework.

Abstract

Abstract In this study, exposure and ecotoxicity data of six human pharmaceuticals (carbamazepine, clofibric acid, diclofenac, ofloxacin, propranolol, and sulfamethoxazole) were collected, including our own experimental data and literature data. From this data collection, the two-tiered European draft guideline on the environmental risk assessment of human pharmaceuticals was tested. Measured environmental concentrations in effluents from France and in effluents and surface waters from Germany were compared to the predicted environmental concentrations (PECs) in both countries. In a similar manner, predicted no-effect concentrations (PNECs) derived from acute data and PNECs derived from chronic data were estimated for each pharmaceutical and corresponding PEC/PNEC ratios then were compared in both countries. Globally, results demonstrated that all environmental concentrations (predicted or measured) for each considered pharmaceutical exceeded the 10-ng/L cutoff value, which requires the implementation of the second-tier assessment based on ecotoxicity data. Moreover, the six pharmaceuticals showed a relatively limited acute toxicity, and carbamazepine and propranolol were inaccurately identified as having negligible risks under the current European draft procedure. Such results lead to discussion of the actual procedure on pharmaceuticals, especially on the need of appropriate ecotoxicity tests.