Impact of anthropopressure on the occurrence and distribution of plastic-related micropollutants in aquatic sediments

Purpose Plastic pollution in water is a global issue. As polymeric materials degrade, micro- and nanoplastics are formed, and release substances used in their production, many of which exhibit estrogenic effects on organisms. The main aim of the study was to investigate the relationship between the concentrations of selected organic compounds, mainly used in plastic production, in the sediments of artificial reservoirs and the land use of their catchments, under varied anthropogenic pressure. Materials and methods The analyzed substances included phthalates (dibutyl phthalate, butyl benzyl phthalate, bis(2-ethylhexyl) phthalate, di-n-octyl phthalate), phthalate substitute (bis(2-ethylhexyl) adipate), and phenol derivatives (4-nonylphenol, 4-tert-octylphenol, bisphenol A). Gas chromatography coupled with mass spectrometry was used to detect selected micropollutants. Sediment parameters, including pH, redox potential, dry matter content, organic and mineral matter, and total organic carbon, were also measured. Spearman’s rank correlation, linear regression, the Kruskal-Wallis test, and Principal Component Analysis (PCA) were used for statistical analysis of the obtained research results. Results and discussion Research on five reservoirs, differing in terms of the spatial development of the catchment area, showed that the varied load of anthropopressure is reflected in the values of pollutant concentrations in sediments. The sum of phthalates and bis(2-ethylhexyl) adipate was 300.8–738.1 µg kg −1 DM, 1466.6–2639.0 µg kg −1 DM, 1053.9–1872.9 µg kg −1 DM, 935.8–3360.9 µg kg −1 DM, and 2976.2–4481.3 µg kg −1 DM in the Nakło-Chechło (Z1), Pławniowice (Z2), Kozłowa Góra (Z3), Rybnickie (Z4), and Dzierżno Duże (Z5) reservoirs. The sum of phenol derivatives was 17.0–56.9 µg kg −1 DM (Z1), 24.2–32.3 µg kg −1 DM (Z2), 20.7–47.1 µg kg −1 DM (Z3), 193.0–284.4 µg kg −1 DM (Z4), and 174.9–258.3 µg kg −1 DM (Z5). Conclusions As the proportion of urbanized and industrial areas in the catchment area increased, both the concentrations and the number of detected pollutants also increased. A relationship was found between plastic additives and the content of organic matter and total organic carbon in sediments. Statistical analyses revealed significant differences in pollutant concentrations among the reservoirs and suggested potential associations between catchment land use and the occurrence of selected compounds, while alkylphenols may also originate from sources unrelated to plastics.