Human exposure to persistent and mobile chemicals: A review of sources, internal levels and health implications

Persistent and mobile chemicals (PMs) are highly polar organic chemicals of anthropogenic origin, which have been documented as an emerging issue of concern for environmental and human health and for which policy needs have recently been identified. Since PMs are recognized as a serious threat to water resources and drinking water, many studies have focused on the occurrence and fate of PMs in aqueous environmental matrices, especially surface water, groundwater and drinking water but considerably less so directly on human exposure. Consequently, our understanding of human exposure to PMs is still limited. In this context, the main objectives of this review are to provide reliable information on PMs and comprehensive knowledge about human internal and relevant external exposure to PMs. This review highlights the occurrence of eight selected PMs: melamine and its derivatives and transformation products, quaternary ammonium compounds, benzotriazoles, benzothiazole and their derivatives and transformation products, 1,4-dioxane, 1,3-di-o-tolylguanidine, 1,3-diphenylguanidine and trifluoromethane sulfonic acid in human matrices (blood, urine, etc.) and environmental samples relevant to human exposure (drinking water, food, indoor dust, etc.). In addition, human biomonitoring data is discussed in the framework of the chemicals risk management policy. Current knowledge gaps of selected PMs from a human exposure perspective, as well as future research needs were also identified. While PMs discussed in this review have been found in various environmental matrices relevant for human exposure, it is important to note that human biomonitoring data for some PMs is very limited. Available data on the estimated daily intakes of some PMs suggest that they do not pose an immediate concern for human exposure.