Finding over-the-counter drugs such as NSAIDs in wastewater is somewhat expected and understandable; however, finding them on surface or groundwater is more worrisome as it demonstrates, in part, the inefficiency of the methods used today to treat wastewater as well as practices of inadequate use and indiscriminate disposal of these emerging contaminants.

The objective of this chapter is to provide a systematic review of the worldwide occurrence of NSAIDs in three environmental reservoirs of water (saline and fresh and groundwater) and in drinking water.

Our results showed that the worldwide distribution of studies on the subject is practically concentrated in Asia and Europe. Acetaminophen, diclofenac, ibuprofen, indomethacin, ketoprofen, naproxen, mefenamic acid, and salicylates are the NSAIDs investigated and most frequently detected in all studies.

Since 2010, research on the occurrence of NSAIDs in environmental water reservoirs has been continuous and consistent. However, the analysis of river waters is much more abundant than those of seas, groundwater, or drinking water. Fortunately in recent years, research has focused on the development of more sensitive but at the same time simpler methods for the detection of NSAIDs in water bodies. Moreover, during the article screening process, we found that in recent years, publications related to toxicity studies in diverse model organisms have increased.

Concentrating the information available to date on the quantities of NSAIDs found in different aquatic ecosystems, through different methods of extraction and analysis, is very useful to direct future research, to design more efficient strategies to minimize the ecological impact of these water pollutants, and to develop evidence-based regulation.