Analyses of polyaromatic compounds (PACs) and metals in sediment and mussels near Kubal aluminium smelter

Summary

In 2019 analyses of polyaromatic compounds (PACs) and metals was conducted in coastal waters around the Kubal smelter and surrounding waterbodies. Levels in both sediments (19 stations) and mussels (Limecola balthica, 5 stations) were investigated. More than 50 different PACs (including alkylated PACs) and 8 metals were analysed. The concentrations of most PACs correlated negatively with distance from Kubal, but this pattern was not observed for metals. PACs that did not correlate negatively with distance from Kubal probably had other sources in addition or instead of Kubal. The PAC pattern in sediments and mussels correlated well, indicating an uptake of PAC from sediment. Concentrations of PACs and metals in sediment were compared with data from 2002 and showed an overall reduction in concentrations for PACs. A mean of 62% reduction of PAC was observed, and a reduction was observed for 75% of the stations investigated both years (n=12). For metals, increasing concentrations were found for As, Mn and Hg, while Cu, Cr and Vn concentrations were decreased. The stations associated with the greatest increase in concentrations were not close to the discharge points of Kubal.