Analysis of some polyhalogenated organic pollutants in sediment and sewage sludge

A laminated sediment core collected in the southern part of the Baltic Proper was analysed for DDT compounds, polychlorinated biphenyls (PCB) including the coplanar congeners, polybrominated diphenyl ethers (PBDE) and polychlorinated naphthalenes (PCN). Two sewage sludge samples were also analysed for the same compounds.

The results of the sediment analyses indicate the presence of PCB, DDT and PBDE compounds in sediment layers dating from the 1950s and later. Neither coplanar PCB nor PCN were detected at any level of the sediment core. The PCB concentrations indicate a slight increase in levels during the last decades, while there were no changes in the levels of DDT compounds. In contrast, TeBDE levels increase 4- to 8-fold and one PeBDE congeners levels increase 10- to 20-fold. The results of sewage sludge analyses showed the concentration of the individual PBDE to be at about the same level as for the individual PCB congeners. The congener pattern in sludge samples indicates low-chlorinated products to be the main PCN source.