A MASS-BALANCE MODEL OF CHLORINATED ORGANIC-MATTER FOR THE BALTIC SEA - A CHALLENGE FOR ECOTOXICOLOGY

A budget, based on an extensive sampling program quantifying concentrations of extractable chlorinated hydrocarbons (EOCI) in input sources, in water and sediment, shows that large amounts of chlorinated organic matter have accumulated in the Baltic Sea. The total amount corresponds to over half of the effluents produced by the pulp-mill industry since chlorine bleaching was introduced in the early 1940s. A numerical model, that also considers possible transport and decay processes, is in agreement with the observed distribution pattern. The model also demonstrates that the Baltic will contain large amounts of chlorinated organic matter for many decades, in spite of the recent reductions in the effluents from industry. However, the chemical composition and toxic effects of the measured bulk parameter EOCI remains largely unknown. The major challenge for environmental science is to develop ecotoxicological concepts and methods to determine the effects of these substances.