Combination of nanoparticles from polystyrene and the hormone 17alpha-ethinylestradiol (EE2) in water.

Plastic materials and synthetic hormones are found in aquatic environments globally. Plastic in water can degrade to nanoparticles (NP) with special characteristics, in the environment nanoparticles and hormones have a proven effect on wildlife. Synthetic hormones are widely used in contraceptives and medications and one of the most common synthetic hormones used is 17-alpha-ethinylestradiol (EE2). The aim of this study was to investigate if nanoparticles from polystyrene interact with the synthetic steroid hormone (EE2) in water. A second aim was to study if the NP and EE2 interacted differently in ISO 6341 standardized freshwater compared to copper free tap water, and if the interaction was different with the common zooplankton Daphnia magna and algae present in the water. This was tested by contaminating water samples separately with EE2 and NP, but also with EE2 and NP together to compare the results. The analysis method used for measuring the hormone had to be developed during this project. The results from this study implies that interaction between NP and EE2 seem to benefit from the standardized freshwater and from D. magna and algae present in the water samples. The interaction does not tell anything about the effect of the combination, which have to be studied further. Studies have been done with NP and EE2 separately and its effects in water before, but studies about both pollutants are very limited. This study is important as it investigate if NP and EE2 interact in water, and if they do the effects of the interaction is of further importance and interest.