Dioxin concentrations in sediments of the Baltic Sea – A survey of existing data
Introduction
The Baltic Sea region is one of the areas most contaminated by persistent organic pollutants (POPs) including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The high load of dioxins in fish has lead to recommendations to restrict the use of contaminated fish from the Baltic for human consumption. Uncertainties about sources, the geographical distribution of these contaminants, their cycling and fate in the sea, the pathways of bioaccumulation and possible ecotoxicological and human health effects are of concern.
Basic knowledge of the sources of PCDD/Fs found in the Baltic Sea is scarce. The inventories and estimates of emissions of PCDD/Fs are severely limited and the comparison of different approaches and their results is difficult. The emission factors used are in many cases based on few samples and probably not representative of fluxes. In addition, information on activity rates and emission profiles is scarce (Wenborn et al., 1999) although for some processes increasingly representative and reliable data have been published (see discussion below). Furthermore, more importance should be attached to cumulative emissions over time and, as part of them, secondary emissions from earlier fluxes and pools, e.g. soils, solids and products and wastes (see e.g. Bergqvist et al., 2005, Assmuth and Jalonen, 2005).
In general, PCDD/Fs enter the Baltic Sea via atmospheric deposition, river input and point sources along the coast. The ultimate sink for the majority of the compounds is the open sea and coastal sediments, although some fraction enters the food chain. Importantly, vertical profiles of sediments reveal past changes in PCDD/F accumulation and inputs, although modifying factors confound such reconstructions. Therefore, analysis of sediment has been widely used to study regional and temporal trends of dioxin pollution in freshwater, estuaries and oceans (e.g., Koistinen et al., 1995, Vartiainen et al., 1995, Vartiainen et al., 1997, Bruckmeier et al., 1997, Witt et al., 1997, Sakurai et al., 2000, Frignani et al., 2001, Green et al., 2001, Wu et al., 2001, Isosaari et al., 2002a, Isosaari et al., 2002b, Marvin et al., 2002, Gotz and Lauer, 2003, Barabas et al., 2004). The Baltic Sea has been one of the most studied sea areas for dioxin-like compounds as well. Only a fraction of the analytical results have been published in scientific papers, however (Rappe and Kjeller, 1987, Rappe et al., 1989, Jonsson et al., 1993, Kjeller and Rappe, 1995, Dannenberger et al., 1997, Koistinen et al., 1997, Witt et al., 1997, Isosaari et al., 2000, Isosaari et al., 2002b, see also Ishaq et al., 2003). Here we summarize and evaluate information on regional distributions of certain congeners of dioxins in surface sediments and in six sediment cores from the Baltic Sea. New survey data from Finland, Sweden and Denmark is merged and compared with data of earlier sediment surveys and case studies.
The purpose of this paper is to
- 1.
Provide a “draft” picture of the regional distribution of key PCDD/Fs (possible hot spots, major regional differences) in surface sediments along the Finnish–Swedish–Danish–German coastal and open sea sites in the Baltic.
- 2.
Analyze differences in congener distributions (source identification).
- 3.
Examine temporal changes reflected in sediment profiles.
- 4.
Identify major areas with data gaps.
Section snippets
Finland
Surface sediment samples along the Finnish coast, one sediment profile from the Gulf of Finland (AKL) and one sediment profile from the previously poorly studied Gulf of Bothnia (SR5) were taken by the Finnish Environment Institute (SYKE) and the Finnish Marine Research Institute in 1997–2003 (Table 1). The samples were collected from known sedimentation areas both near the coast and offshore using pistonless corers with an inner diameter from 9.0 to 13 cm. All the sediment cores were divided
Results and discussion
The main interest was to study the spatial distribution of dioxins and the contribution of identified point sources in Finland and Sweden to sediment dioxin levels. For this purpose, we focused on certain point source-identified congeners. The selected congeners reflecting specific point sources were 2,3,7,8-TCDD (TCDD), 2,3,7,8-TCDF (TCDF), and OCDF as indicators of pulp bleaching and vinyl chloride production (Rappe et al., 1989; Koistinen et al., 1992; Isosaari et al., 2000), and
Conclusions
The survey confirms the impact of Kymijoki-derived, highly chlorinated, PCDF-congeners to the total toxicity in sediments in the Gulf of Finland. However, the findings do not support that any of the known point sources would significantly influence those congeners that are most abundant in Baltic herring and salmon. Instead, regional distributions in the Baltic Sea indicate that atmospheric deposition may act as a major source for those congeners. On the other hand, some signatures of point
Acknowledgements
We thank all technical personnel involved in the sampling and laboratory analysis. The work was partially funded by the Ministry of Environment, Finland, the Swedish EPA, the Geological Survey of Sweden and the Danish Environment Protection Agency.
References (63)
- et al.
Patterns and levels of organochlorines (DDTs, PCBs, non-ortho PCBs and PCDD/Fs) in male harbour porpoises (Phocoena phocoena) from the Baltic Sea, the Kattegat-Skagerrak Seas and the West Coast of Norway
Marine Pollution Bulletin
(1999) - et al.
Dioxins in cod and herring from the seas around Sweden
Chemosphere
(1989) - et al.
PCBs and PCDD/Fs in lake sediments of Großer Arbersee, Bavarian Forest, South Germany
Environmental Pollution
(1997) - et al.
Fingerprints of dioxin from thermal industrial processes
Chemosphere
(2000) - et al.
Dioxins from thermal and metallurgical processes: recent studies for the iron and steel industry
Chemosphere
(2001) - et al.
Levels and patterns of polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in surface sediments from the Western Baltic Sea (Arkona Basin) and the Oder River Estuarine system
Marine Pollution Bulletin
(1997) Secondary exposure to dioxins through exposure to PCP and its derivatives
Science of the Total Environment
(1999)- et al.
Accumulation of polychlorinated dibenzo-p-dioxins and dibenzofurans in sediments of the Venice Lagoon and the industrial area of Porto Marghera
Marine Pollution Bulletin
(2001) - et al.
Polychlorinated biphenyl congeners as markers of toxic equivalents of polychlorinated biphenyls, dibenzo-p-dioxins and dibenzofurans in breast milk
Environmental Research
(2001) - et al.
PCBs, PCNs, PCDD/Fs, PAHs and Cl-PAHs in air and water particulate samples—patterns and variations
Chemosphere
(2003)
PCDD/F and PCB history in dated sediments of a rural lake
Chemosphere
Levels and trends of PCDD/Fs and PCBs in human milk in Finland
Chemosphere
PCDD/Fs and PCB in Baltic herring during the 1990s
Chemosphere
Polychlorinated diphenyl ethers, dibenzo-p-dioxins, dibenzofurans and biphenyls in Seals and sediment from the Gulf of Finland
Chemosphere
Dioxins and furans in air and deposition: a review of levels, behaviour and processes
The Science of the Total Environment
Persistent organic pollutants in Detroit River suspended sediments: polychlorinated dibenzo-p-dioxins and dibenzofurans, dioxin-like polychlorinated biphenyls and polychlorinated naphthalenes
Chemosphere
Sources of PCDDs and PCDFs. Introduction. Reactions, levels, patterns, profiles and trends
Chemosphere
PCDDs and PCDFs in environmental samples air, particulates, sediments and soil
Chemosphere
Levels, trends and patterns of PCDDs and PCDFs in scandinavian environmental samples
Chemosphere
Levels of PCDDs and PCDFs in products and effluent from the Swedish pulp and paper industry and chloralkali process
Chemosphere
Levels, profile and pattern of PCDDs and PCDFs in samples related to the production and use of chlorine
Chemosphere
Polychlorinated dibenzo-p-dioxins and dibenzofurans in sediment, soil, fish, shellfish and crab samples from Tokyo Bay area, Japan
Chemosphere
PCDD/F sources and levels in River Elbe sediments
Water Research
Fate of 1,2,3,4,6,7,8-heptachlorodibenzofuran and pentachlorophenol during laboratory-scale anaerobic mesophilic sewage sludge digestion
Chemosphere
Polychlorodibenzo-p-dioxin and polychlorodibenzofuran concentrations in lake sediments and fish after ground water pollution with chlorophenols
Chemosphere
Levels of PCDD, PCDF and PCB in dated lake sediments in Subarctic Finland
Chemosphere
Estimation of dioxin emission from fires in chemicals
Chemosphere
Multivariate data evaluation of PCB and dioxin profiles in the general population in Sweden and Spain
Chemosphere
Occurrence and distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans in sediments of the Western Baltic Sea
Chemosphere
Mobility and profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans in sediment of Ya-Er Lake, China
Water Research
Cited by (0)
- 1
Present address: VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT.