2 STATUS AND TRENDS OF HAZARDOUS SUBSTANCES
2.1 Integrated assessment and classifi cation of “hazardous substances status”
substances status”
2.1.1 Methods of the integrated assessment
The hazardous substances status has been assessed and classifi ed at 144 sites in the Baltic Sea using the HELCOM Hazardous Substances Status Assessment Tool (CHASE), which is a multi-metric indicator-based tool developed for the HELCOM integrated thematic assessment of haz-ardous substances in the Baltic Sea. The CHASE tool produces an integrated assessment and clas-sifi cation of “hazardous substances status”, which is advantageous for use in setting a baseline for the implementation of the HELCOM Baltic Sea Action Plan (HELCOM 2007a) and, in particular, for the science-based evaluation of whether the overall goal of “a Baltic Sea with life undisturbed by hazardous substances” has been achieved.
This integrated CHASE assessment of hazardous substances in the Baltic Sea is based on quality-assured monitoring data (1999–2007) on various chemicals, the radionuclide cesium-137 and certain indicators of biological effects. These data are considered in relation to the four ecological objectives in the hazardous substances segment of the HELCOM Baltic Sea Action Plan refl ecting the HELCOM strategic goal for hazardous sub-stances (Table 2.1).
Table 2.1 HELCOM’s strategic goal and ecological objectives for hazardous substances (HELCOM 2007a).
11
The classifi cation results of the integrated CHASE assessments do not always give assessment results which are equivalent to the assessment results of chemical status made according to the EU Water Framework Directive (Anon. 2000a). This is due to differences in, e.g., the selection of substances, the assessment method used, and the areas assessed.
See Annex 2 for further details on the relationship between the assessment approaches of the WFD and CHASE.
Altogether, 144 assessment units were analysed using CHASE: 40 of the assessment units were open-sea areas and 104 were coastal sites or areas.
2.1.2 Results of the integrated assessment
All open-sea areas of the Baltic Sea were classi-fi ed as “disturbed by hazardous substances” and received a status classifi cation of “moderate”,
“poor” or “bad” (Fig. 2.1). The only exception was the northwestern Kattegat, which received a status classifi cation of “good”. Open waters in the North-ern Baltic Proper, WestNorth-ern and EastNorth-ern Gotland Basins, the Gulf of Finland and the Gulf of Gdansk received the lowest status classifi cations (bad or poor), while the open-sea areas in the Gulfs of Bothnia and Riga, Arkona and Bornholm Basins, and Danish open waters were mainly classifi ed as being in moderate status.
Only six of the 104 coastal assessment units were classifi ed as ”areas not disturbed by hazardous substances” and received a status classifi cation of good or high (Fig. 2.1). The status of coastal assessment units varied from high to bad without particular consistency. The coastal areas that received the highest status classifi cations were located in the Åland Islands area, in the Kaliningrad coastal area, on the Lithuanian coast, in the Kat-tegat and on the Finnish side of the Bothnian Bay.
There was some tendency for the assessment units with the poorest status to be located either near big cities or ports (Tallinn, Klaipeda) or to be estua-rine areas (Ruotsinpyhtää in the Gulf of Finland), Kvädöfjörden in the Western Gotland Basin) or coastal sites (the Kiel Bay area). The waters near large coastal cities were generally classifi ed as having a “moderate” hazardous substances status (e.g., St. Petersburg, Helsinki, Stockholm, Riga, Gdansk and Copenhagen).
weights. These differences may affect the compari-son of these assessment results to those of different countries.
When interpreting the CHASE results, it is impor-tant to keep in mind that the status classifi cations for the different assessment units may be affected by different combinations and numbers of sub-stances monitored and that this may affect the comparability among the assessment units. More information on the CHASE integrated assessment method is included in Annex 1.
Figure 2.1 Integrated classifi cation of the hazardous substances status in the 144 assessment units. Blue = high status, green = good, yellow = moderate, orange = poor, and red = bad status. High and good status are equivalent to
“areas not disturbed by hazardous substances”, while moderate, poor, and bad status are equivalent to “areas disturbed by hazardous substances”. Large dots represent assessment units of the open basins; small dots represent coastal assessment units which are mainly located in the territorial waters delimited by the grey line. Other grey lines represent the divisions between the sub-basins (cf. Fig. 1.1). Ecological objectives that were assessed using CHASE included all HELCOM objectives: “Concentrations of hazardous sub-stances close to natural levels”, “All fi sh safe to eat”, “Healthy wildlife” and
“Radioactivity at pre-Chernobyl levels”. See Annexes 1 and 2 for details.
12
Elevated levels of radionuclides were found in the northern, eastern and central parts of the Baltic Sea, while the levels were close to pre-Chernobyl levels in the southwestern parts of the Baltic Sea.
These elevated levels did not, however, affect the fi nal status classifi cation in those areas, as shown on the map (Fig. 2.2) with the results of the CHASE assessment carried out excluding the radionuclides.
Only in two assessment units (open-sea areas “Kiel Bight East” and “Southwest Arkona Basin”) was the fi nal classifi cation caused by elevated levels of radionuclides (Fig. 2.2).
Although most parts of the Baltic Sea were classi-fi ed as “disturbed by hazardous substances”, there were differences in the classifi cations between various parts of the Baltic Sea (Fig. 2.3). Generally, undisturbed areas were found at wave-exposed sites such as the Åland Archipelago and the coastal waters off Kaliningrad. The northern parts of the Baltic Proper, Western Gotland Basin as well as the Kiel Bight and Mecklenburg Bight were areas with a poorer status.
The ecological objectives that most often determined the fi nal classifi cation were “Concentrations close to natural levels” (in 63% of the 144 assessment units),
“All fi sh safe to eat” (3%), “Radioactivity at pre-Chernobyl levels” (2%) and “Healthy wildlife” (1%).
Altogether, for 24% of the assessment units, the fi nal classifi cation was determined by two different elements and for 9% of the units by three elements.
Figure 2.2 Status classifi cations carried out excluding radionuclides. Only in the open-sea areas “Kiel Bight East” and “Southwest Arkona Basin” was the fi nal classifi cation caused by elevated levels of radionuclides. For other information, see Fig. 2.1.
Figure 2.3 Integrated classifi cation of “hazardous substances status” in the 14 Baltic Sea basins, with the number of assessment units indicated for each basin. Blue = high status, green = good, yellow = moderate, orange = poor, and red = bad status.
0 % 20 % 40 % 60 % 80 % 100 %
Bothnian Bay (9) Bothnian Sea (10) Archipelago and Åland Seas (4) Baltic Proper, northern parts (7) Gulf of Finland (14) Baltic Proper, Western Gotland Basin (5) Baltic Proper, Eastern Gotland Basin (22) Gulf of Riga (10) Gulf of Gdansk (5) Bornholm Basin (9) Arkona Basin (11) Kiel Bight and Mecklenburg Bight (13) Danish Straits (9) Kattegat (16)
high good moderate poor bad
13
in twelve assessment units (Table 2.1). The reason for this is that the indicators under each ecological objective assessed in CHASE are integrated using a method that takes into account the number of indicators in addition to the CRs (see Annex 1).
Cesium-137 was always the single indicator under the ecological objective “Radioactivity at pre-Cher-nobyl levels”, while the other ecological objectives and especially “Concentrations close to natural levels” were always assessed with a number of indicators.
A great variety of different substances exceeded the threshold levels in the different Baltic Sea sub-basins (Table 2.2). Substances that were found to exceed threshold levels in nearly all sub-basins An important question is “Which substances are
decisive in determining the status in the integrated classifi cation?” PCBs, lead, mercury, cesium-137, DDT/DDE, TBT, benz[a]anthracene and cadmium were the substances most commonly observed with the highest Contamination Ratios (CR, i.e., having the highest concentrations in relation to target levels) in the assessment units classifi ed as “mod-erate”, “poor” or “bad” (Table 2.1). PCBs were among the substances with the highest CRs in 20%
of the units, and lead, mercury, cesium-137, TBT and DDT/DDE in 9% and cadmium in 7% of the units (Table 2.1). All common groups of hazardous sub-stances—PCBs, dioxins, heavy metals, organomet-als, alkylphenols, phthalates, brominated substances, polycyclic aromatic hydrocarbons (PAHs), DDTs and chlorinated pesticides as well as the radionuclide cesium-137—were found among the substances with the highest CRs (Table 2.1).
The data in the integrated assessment were prima-rily from biota and only secondaprima-rily from sediment or water. Therefore, the above-mentioned decisive substances were mainly found in fi sh, mussels and birds and only secondarily in sediment or water samples. Data from water were only reported from eight offshore assessment units and nine coastal assessment units. There was no site where the assessment was based solely on indicators in the water phase.
Cesium-137 did not affect the fi nal classifi cation of the assessment units, except in two areas (cf. Figs.
2.1 and 2.2), although the substance was found in high concentrations and even with the highest CRs
Table 2.1 Observations of hazardous substances with the highest concentrations in relation to the target level (i.e., the highest Contamination Ratio, CR) in the 137 assessment units classifi ed as “areas disturbed by hazardous substances”. See the glos-sary for the abbreviations.
Substances with the highest CRs in 137 assessment
units, number of observations %
PCBs 27 20
Lead 13 9
Mercury 13 9
137Cesium 12 9
DDT/DDE 3/9 9
Tributyltin 11 8
Benz[a]anthracene 9 7
Cadmium 7 5
Dioxins/DL-PCBs 4 3
Nonylphenol 4 3
Zinc 4 3
VDSI-index 3 2
Arsenic 2 1
DEHP 2 1
HCHs 2 1
Nickel 2 1
Octylphenol 2 1
PBDE 2 1
Anthracene 1 1
Benzo[ghi]perylene 1 1
Benzo[k]fl uoranthene 1 1
Copper 1 1
Fluorene 1 1
PAH-metabolites 1 1
Total 137 100
14
while nonylphenol was only mentioned for the Belt Sea and Kattegat.
included PCBs, DDT/DDE, cadmium, lead, TBT and cesium-137. Mercury exceeded the threshold levels particularly in the central and northern basins,
Table 2.2 Distribution of the substances with the highest concentrations in relation to target levels (i.e., the highest Contamination Ratio, CR) in the 137 assessment units classifi ed as “areas disturbed by hazardous substances” in the different sub-basins of the Baltic Sea. Numbers in parentheses indicate the number of times the substance was found having the highest CR in the assessment units of the basin. See the glossary for the abbreviations.
Baltic Sea sub-basin Substances
Bothnian Bay Cadmium, cesium-137 (3), BDE, DDE, DEHP and PCB
Bothnian Sea Cadmium, cesium-137, DDE (2), dioxins (2), HCHs, lead and mercury (2) Åland Sea and Archipelago Sea Cesium-137 and PCB
Northern Baltic Proper BDE*, cadmium, DDE*, lead, octylphenol, PCB (2) and TBT
Gulf of Finland Cadmium, cesium-137, copper, DDT, lead, mercury (6), TBT and zinc (2) Gulf of Riga DDT (2), lead (4), PCB (3) and zinc
Eastern Baltic Proper Anthracene, benz[a]anthracene (8), benzo[k]fl uoranthene (1), cesium-137 (2), DDE (2), dioxins, mercury (3) and TBT (3)
Western Gotland Basin DDE, dioxins, nickel and PCB (2)
Gulf of Gdansk Benz[a]anthracene, cesium-137, mercury and PCB
Bornholm Basin Cadmium, cesium-137, DDE (2), lead, PCB (2), TBT and zinc
Arkona Basin Benzo[g,h,i]perylene, cadmium (2), cesium-137, DDE, lead (2), mercury, PCB (3) and TBT
Mecklenburg and Kiel Bight Cesium-137, HCHs, lead (3), PAH-metabolites and PCB (7) Belt Sea and the Sound Arsenic, DEHP, nonylphenol (3), PCB (2), VDSI and TBT
Kattegat Arsenic, BDE, fl uorene, nickel, nonylphenol, octylphenol, PCB (3), TBT (3) and VDSI (2)
*)The substances had equal weight at the site.
15