The presence of pharmaceuticals in the environment due to human use--present knowledge and future challenges.

Intensive research on pharmaceuticals in the environment started about 15 years ago. Since then a vast amount of literature has been published. The input and presence of active pharmaceutical ingredients (APIs) and their fate in the environment were and is still of high interest. As it has been extensively demonstrated that the active compounds are present in the environment some of the research interest has moved from analysis of the compounds, which is still undertaken, to effect studies in the lab and in field trials. It has been found that environmental concentrations can cause effects in wildlife if proper tools are applied for effect assessment. The question of mixture toxicity has gained more and more attention. It has been learned that classical tests may underestimate effects and risks. Work has been done in the field of risk assessment and risk management. As for risk management strategies to eliminate pharmaceuticals from wastewater or from the effluent of sewage treatment plants have been proposed and investigated. A tremendous amount of literature can now be found describing technical management measures such as oxidative or photolytic effluent treatment, filtering techniques, and application of charcoal. It has been learned however, that each of these approaches has its specific shortcomings. Therefore, additional approaches such as including people handling and using the compounds, and focusing on the properties of the compounds ("green pharmacy") came into focus. Accordingly, this review gives an overview of the present state of knowledge presenting typical results and lines of discussion. This review makes no claim to give a complete overview including the full detailed body of knowledge of pharmaceuticals in the environment. Rather, it addresses important and typical topics to stimulate discussion.