Adsorption of Organic Pollutants in Microplastic in the Arctic Ocean

Abstract

Oceans all over the world are housing large quantities of plastic pollution and persistent organic pollutants (POPs). Concerns regarding both of them having lipophilic characteristic that allows a successful partitioning of POPs to plastic if in contact in an aqueous medium, led to this study where the relationship between different types of plastic and POPs in the Arctic ocean are looked into. In two seasons, respectively summer and winter, pellets of polyethylene high- density (PE-HD), polyethylene low-density (PE-LD), polyethylene terephthalate (PET) and polypropylene (PP) have been located in Kongsfjorden, the Arctic ocean outside Ny-Ålesund, Svalbard. The concentration of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in plastics have been analysed before entering the ocean and during the seasons. Also, a selection of marine plastic garbage collected in Longyearbyen, Svalbard, was identified and analysed. The POPs adsorb more to rubbery polymers (PH-HD, PE-LD, PP) than glassy polymers (PET). A clear variation between type of plastic and concentration was found, from highest to lowest: PE-HD > PE-LD > PP > PET. The plastics stability in regard to chemical structure and possible surface changes was investigated with Fourier-transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) respectively. All plastics were chemically stable after being in the ocean. Among the garbage samples, differences concerning how and how many particles breaking of as microplastics and type of plastic were discovered. Based on results in this study, PE-HD is classified as the most harmful and PET the least harmful type of plastic if entering the Arctic marine environment, both regarding adsorption of POPs and degree of degradation.