Microplastic and associated polyaromatic hydrocarbons in surface waters feeding Beyşehir Lake in Türkiye

The detection of microplastics, defined as tiny plastics particles having a size from 1 µm to 5 mm, in aquatic environments has become a serious concern worldwide. Microplastics may be introduced either directly to water bodies or indirectly to the aquatic systems. In particular, microplastics may interact with persistent organic pollutants and inorganic contaminants and they transfer these pollutants to organisms in the aquatic environment. In this study, microplastics and their sorbed polyaromatic hydrocarbons (PAHs) in the surface water feeding Beyşehir Lake in Türkiye were investigated. The abundance of microplastics in the surface water was determined in the range of 2830-6860 particles/m3. While five shapes (fiber, foam, film, fragment, pellet) of microplastics were determined in surface waters, fiber and fragment form microplastics were predominantly observed. The detected polymer types were cellophane, polyethylene, polypropylene. The transparent/white color microplastics were the most dominant (42-81%). The total concentration of the seventeen PAHs associated with microplastics in surface waters ranged from 1924 to 7970 ng/g. According to the diagnostic ratios of the PAH isomers (fluoranthane/pyrene < 1 and phenanthrene/antracene >10), the source of the PAHs all surface waters can be pyrogenic and petrogenic origins. These findings indicate that high concentrations of microplastics and PAHs sorbed microplastics were carried into the lake by the surface waters feeding Beyşehir Lake. These pollutants may pose a risk to the use of water for irrigation and potable purposes and to aquatic organisms in the lake.