Concentrations of levonorgestrel and ethinylestradiol in wastewater effluents: is the progestin also cause for concern?
Synthetic hormones have been widely reported in treated sewage effluents, and consequently receiving aquatic environments. Ethinylestradiol (EE2) is a potent synthetic estrogen commonly used in conjunction with levonorgestrel (LNG) in oral contraceptive pills. EE2 and LNG have been identified in the aquatic environment, but while there is a significant amount of literature on EE2, there is much less information on LNG. Using Australian prescription data, excretion and predicted wastewater removal rates, the concentrations of EE2 and LNG in Australian wastewater were calculated at 0.1‐0.5 ng/L and 0.2‐0.6 ng/L, respectively. Both compounds were analysed in treated wastewater and surface water grab samples from three Southeast Queensland sites. The Predicted No Effect Concentration (PNEC) for EE2 of 0.1 ng/L was exceeded at most sites, with EE2 concentrations up to 2 ng/L in treated effluent, albeit quickly diluted to 0.1‐0.2 ng/L in the receiving environment. A provisional PNEC for LNG of 0.1 ng/L derived in the present study was slightly lower than predicted effluent concentrations of 0.2‐0.6 ng/L, indicating a potential risk of endocrine‐related effects in exposed aquatic species. The detection limit for LNG in the present study was 2.5 ng/L, and all samples were below detection limit. These results suggest that improvements in analytical capabilities for LNG are warranted to more accurately quantify the risk of this compound in the receiving environment. This article is protected by copyright. All rights reserved