Читать книгу Applied Water Science - Группа авторов - Страница 27

Aquatic systems, including surface water (rivers and reservoirs) and groundwater systems act as important sources of drinking water, aquatic foods, water for food production and recreational purposes (e.g., swimming). Thus, human exposure risks may arise via (1) direct ingestion in drinking water (groundwater or treated tap water) and (2) consumption of contaminated aquatic foods (freshwater or marine fish) and even vegetables irrigated with contaminated wastewater (Figures 2.1 and 2.2). Human exposure may also occur vial dermal or skin contact (e.g., during swimming) and via inhalation (Figure 2.2), but data on this aspect is still lacking. Dermal contact and inhalation were mentioned in just a few studies as routes of exposure (Heron et al., 2003; Daughton et al., 2009). Although pharmaceuticals can be released in sweat and urine (Daughton et al., 2009), epidemiological evidence which shows that the significance of human exposure to such excretions and associated risks appears limited. Two studies have also investigated occupational exposure using concentrations of pharmaceutical in the environment reported in literature (Nimmen et al., 2006; Sermejain et al., 2018). In the same studies, the human health risks were insignificant. However, such studies often focus on a few pharmaceuticals while excluding several others detected in aquatic systems.

Figure 2.2 Human exposure pathways to pharmaceuticals in the environment.

Human exposure via drinking water has been shown to present the highest hazard of all these human exposure pathways (Kumar and Xagoraraki et al., 2010; Bordin et al., 2014; Miller et al., 2018). This risk is particularly high in cases where communities rely on untreated water for drinking purposes. Compared to conventional treatment processes, drinking water treated by membrane separation processes including reverse osmosis (RO), membrane distillation, and nanofiltration (NF) have been shown to have lower concentrations of pharmaceuticals (Licona et al., 2018; Foureaux et al., 2019; Couto et al., 2020). Thus, such drinking water may present lower toxicological and human health risks than raw water and treated water from conventional water treatment methods.