Occurrence of Pharmaceuticals in the Environment

Roughly 4,000 pharmaceuticals are manufactured and marketed in the world for use in the treatment, prevention, and diagnosis of diverse diseases in humans and animals. Once their role in body systems has been accomplished, these compounds are excreted from the body, having aquatic ecosystems as their final destination. Pharmaceuticals are also released into the environment as a result of manufacturing processes and inadequate disposal of unused or expired medications. The environmental concentrations that have been detected in water systems are usually at trace levels (ng L⁻¹ to μg L⁻¹) since removal in sewage treatment plants is not significant for most pharmaceuticals as these facilities have not been designed to reduce or eliminate these contaminants, representing instead a continuous contribution to the environment. Effluents have been identified as the main entry route of pharmaceuticals into the environment. This chapter aims to review, compile, and analyze research studies on the occurrence of pharmaceuticals in the environment.