Determination of Selected Organic Contaminants in the Port of Gdynia Sediments: Towards Cleaner Baltic Ports

Seaports affect the environment through various functions related to cargo handling, connectivity to the sea and land transport networks, and industrial, logistics, and distribution activities. The purpose of this study was to perform a preliminary assessment of the contents of dioxins and microplastics in the bottom sediments of the Port of Gdynia. The identification of plastic particles was carried out on the basis of visual and microscopic observations, as well as spectroscopy analysis. Fragments and fibres were dominant when categorised by particle shape, while transparent, white, and black particles dominated when categorised by colour. The predominant polymer types identified polyolefins and their derivatives. These findings suggest that low-density plastics are present in seabed sediments, probably as a result of biofouling. Samples were also tested for the presence of dioxins. In the sediment surface layer, the highest concentrations were obtained for octachlorodibenzo-p-dioxin (5.54–962 ng/kg d.m.), which has low toxicity. The most toxic congener (2,3,7,8-tetrachlorodibenzo-p-dioxin) was present in very low concentrations (0.19–0.32 ng/kg s.m.). The values of the toxicity coefficient ranged from 0.01 to 9.77 ng/kg s.m. The results showed that in the studied bottom zones in Gdynia Port, the analysed pollutants do not cause a high ecological risk and do not require permanent monitoring.