Initial evaluation of the combined effects of nanoplastics and 17α-ethinylestradiol on D. magna

Abstract: Exposure of combined pollutants is as of today not a very well-researched field of environmental science due to the complex interactions that may occur. Nanoplastic particles (NP) in particular are lacking studies due to the relatively new interest in the subject. In this study, a small experiment in a lab environment was performed that observed the combined effects of polysterene NP and 17α-ethinylestradiol (EE2), a common steroid found in many contraceptive products, on the commonly used zooplankton Daphnia magna. Observations were made on mortality, reproduction, and neonate growth. When exposed to NP alone, a trend of increased reproduction by the initial set of adults, and a subsequent reduction of growth of the following neonates, to the point of these not being able to produce eggs of their own, could be observed. These effects could not be observed among the specimens treated only with EE2 or the combination of both EE2 and NP, implying an antagonistic interaction between the two pollutants. Lastly, this study implores further research on combined effects of pollutants, and the effects of NP, to improve future environmental risk assessments.