Microplastics and nanoplastics in groundwater: Occurrence, analysis, and identification

Microplastics and nanoplastics (MPs/NPs) are a growing environmental concern owing to their widespread distribution and potential adverse effects on ecosystems and human health. Numerous studies on MPs/NPs have focused on their distribution, behavior, and fate; however, there is a lack of knowledge regarding these materials in groundwater, a primary source of drinking water. This is attributed to the difficulties in conducting such studies, the absence of universally accepted standard procedures, and the absence of a global consensus on efficient and accurate analytical protocols. These factors hinder direct data comparison and evaluation. This review provides a summary of the sources of MPs/NPs and their worldwide distribution in groundwater, and categorizes the analytical methods employed for their characterization, including sampling and pretreatment procedures. Finally, promising new technologies for the detection and characterization of MPs/NPs are discussed.