Environmental Microplastics as Vectors of Non-Polar Organic Pollutants in Drinking Water

Microplastics (MPs) in drinking water (DW) raise concerns about their potential impacts on health. Several substances, such as plasticizers and stabilizers, can be leached from plastic polymers following abiotic and biotic denaturation processes. Furthermore, the purification treatment of DW, such as the chlorination process, significantly increases the release of chemical components that are part of the polymer composition. Recently, several studies reported that MPs can adsorb environmental xenobiotics, such as organic molecules and heavy metals, thanks to their surface characteristics acquired in the environment in which they are dispersed. This study aims to evaluate the ability of MPs of different sizes (5 µm and 1 µm) oxidized by UVB exposure to adsorb water-dispersed organic pollutants such as benzo-a-pyrene (BaP). We used Fourier transform infrared spectroscopy and Ζ-potential measurements to characterize MPs particles after UVB exposure and gas chromatography-mass spectrometry to determine the adsorptive capacity of oxidized MPs. The analytical results obtained from the present study demonstrate that oxidized MPs have a significant capacity to adsorb BaP dispersed in the aqueous environment and to act as a vehicle for apolar organic substances by concentrating them. This study raises an alert on the dual potential risk determined by the consumption of DW in which MPs can concentrate and convey environmental xenobiotics, in addition to deciding adverse effects related to their chemical-physical properties.