STUK-A94 FEBRUARY 1992

Radioactivity of surface water and freshwater fish in Finland in 1988-1990

Supplement 6 to Annual Report STUK-A89

R. Saxen and U. Koskelainen STUK-A94 FEBRUARY 1992

Radioactivity of surface water and freshwater fish in Finland in 1988-1990

Supplement 6 to Annual Report STUK-A89

R. Saxen and U. Koskelainen

FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY P.O. Box 268, SF-00101 HELSINKI Finland Tel. +358 0 70821 ISBN 951-47-5936-2 ISSN 0781-1705

The Finnish Government Printing Centre Helsinki 1992

Sold by: The Finnish Government Printing Centre P.O. Box 516 SF-00101 HELSINKI Tel.+358 0 56601 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

SAXEN R, KOSKEL-UNEN U. Radioactivity of surface water and freshwater fish in Finland in 19SS-1990. Supplement 6 to Annual Report STUK-AS9, Helsinki 1991.

ISSN 0781-1705 ISBN 951-47-5936-2

Key words Radiocesium, ^Sr, surface water, freshwater fish

ABSTRACT

Changes over time in the activity concentrations of radionuclides in surface water and in the five largest rivers and some smaller rivers discharging into the Baltic Sea were monitored in 1988-1990. The dominant gamma-emitting radionuclides were 137Cs and 134Cs. The effect of the uneven distribution of Chernobyl deposition is still seen in the results. The activity concentrations of 137Cs in surface water have de­ creased significantly: In the drainage area where the activity concentrations were highest after the Chernobyl accident, the concentrations in October 1990 were only about 1-4% of the maximum values in May 1986. The decrease in the activity concentrations of ^Sr was much slighter. Different changes overtime of the activity concentrations of 137Cs and ^Sr can be attributed to the different behaviour of these two radionuclides in the aquatic environment.

The study of areal and temporal changes in the activity concentrations of 137Cs in fish, started in 1986, continued in 1988 - 1990. In all, about 2400 fish samples from southern and middle Finland (excluding Lapland) were analysed gammaspec- trometrically during these three years. Seventeen different fish species were in­ cluded in the study. The highest activity concentrations of 137Cs were detected in small oligotrophic lakes in the area of highest deposition. Predatory fishes reached maximum values of 137Cs the latest, in 1988, while non-predators had maximum values in the year of the accident, 1986, and part-predators (intermediate) in 1987. The nationwide mean concentrations of 137Cs, weighted for catches, in the three fish groups (predatory, non-predatory and intermediate) were: 1988 1989 1990 Predatory fishes 1300 980 740 Non-predatory fishes 410 220 180 Intermediate 860 650 520

3 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

The average intake of "7Cs via freshwater fish countrywide was about 3400, 2500 and 1900 Bq a"1 in 1988, 1989 and 1990, respectively.

During the fresh fallout situation in 1986, transfer factors from water to predatory, non-predatory and intermediate fish varied from about 200 to 1900 in different drainage areas. In 1990, when the situation had stabilized, these factors varied from about 2 300 to 30 000. Maximum transfer from deposition to fish was 0.2-0.3 m2/kg, which means that 20-30% of the amount of "7Cs deposited in one nr transferred to one kg of fish. For the whole country, transfer factors from deposition to edible fish were 0.01-0.1 m2/kg in 1986-1990.

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CONTENTS page

A RETRACT -5

1 INTRODUCTION 6

1.1 Lakes in Finland 6 1.2 Monitoring of surface water 6 1.3 Monitoring of fish 7

2 MATERIAL AND METHODS 8

2.1 Surface water 8 2.1.1 Samples 8 2.1.2 Pre-treatment and analyses 8 2.2 Fish 9 2.2.1 Sampling 9 2.2.2 Sample treatment 11 2.2.3 Gamma-spectrometric analyses 12 2.2.4 Data treatment 12 2.2.5 Areal averages of 137Cs in fish and intake via fish 13 2.2.6 Transfer of 137Cs from water to fish 13 2.2.7 Transfer of 137Cs from Chernobyl deposition to fish 14

3 RESULTS 15

3.1 Surface water 15 3.2 Fish 16 3.2.1 Radionuclide contents 16 3.2.2 Areal averages of 137Cs in fish and intake via i fish 17 3.2.3 Transfer of 137Cs from water to fish 18 3.2.4 Transfer of 137Cs from Chernobyl deposition to fish 18

4 DISCUSSSION 19

4.1 Surface water 19 4.2 Fish 19

ACKNOWLEDGEMENTS 22 REFERENCES 23 FIGURES 25 TABLES 37 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

1 INTRODUCTION

1.1 Lakes in Finland

In Finland, freshwater lakes and rivers cover an area of 33 600 km2, which is 9.9% of the total area of the country. The number of lakes (surface area > 1 ha) is about 56 000. They are most abundant in central and eastern Finland, where about 25% of the total area is water in some places. Finnish lakes are shallow, their average depth being about 7 m. The total volume of the lakes is about 230 km3. The following figures give the size distribution of Finnish lakes:

Surface area Number of lakes

> 200 km2 17 > 100 km2 37 > 50 km2 81 > 1km2 2 589 > lha 56 000

Besides the above-mentioned lakes, there are almost 132 000 very small lakes or ponds with an average area of 5 a - 1 ha.3,4 The 37 lakes with surface areas of > 100 km2 account for nearly 50% of the total surface area of lakes in Finland and for over 60% of the total volume of the lakes.

1.2 Monitoring of surface water

Monitoring of radioactivity in fresh surface water in Finland was continued with an extensive sampling programme. The results for 1986 and 1987 have been given in earlier reports.12,14 The purpose of the monitoring was to acquire areal data for estimations of intake from drinking water and to gather radioecological infor­ mation on environmental factors affecting the behaviour of radionuclides in different drainage areas.

By analysing the contents of radionuclides in samples from the mouths of the five largest rivers in Finland, the abundances of radionuclides transported by the rivers to the Baltic Sea, can be estimated.

6 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

1.3 Monitoring of fish

Because the unevenly distributed deposition and environmental factors cause considerable variation in the activity concentrations of 137Cs in fish, the study on the radioactivity of freshwater fish was continued with a rather extensive monitoring programme in 1988 -1990. The results for 1986 and 1987 have been given in earlier reports.13-14

The study was undertaken to monitor fish as a food, that is, to evaluate the importance of freshwater fish as a source of radiocesium to consumers in different parts of the country.

Attention was also paid to the differences in radioactivity between fish species and fish groups with different feeding habits. The characteristics of the lakes, such as area, water volume, flow rate and limnological type, and the characteristics of the catchment area also affect the contamination of fish by radioactive substances. However, not all these points are discussed at any length in this paper.

The results reported here present figures for the average intake of 137Cs via freshwater fish and thus form a basis for estimating radiation doses to man via freshwater fish in various drainage areas in Finland and in the country as a whole. The doses are assessed in the annual reports for 1988 - 1990. Estimations of transfer factors from water to fish and from deposition to fish are made for different drainage areas.

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2 MATERIAL AND METHODS

2.1 Surface water

2.1.1 Samples

The sampling programme, comprising some 180 sampling stations in different parts of Finland (Fig. 1)WM\ was continued to determine the distribution of radioactive substances deposited in the surface waters of drainage basins. The seasonal hydrological variations were considered by taking the samples four times a year in 1988: in March, May, August and October. In 1989 the samples were taken only in May, August and October, and in 1990 only in May and October.

The sample volume from each station was 2 litres. Before analyses, the samples were grouped together to represent different drainage basins or their subregions or watercourses (Fig. 2). Thus the volumes of the samples analysed ranged from 6 to 60 1, depending on how many samples were bulked together.

The artificial radioactive substances transported in rivers from Finland to the Baltic Sea were monitored as before. Samples were taken from the mouths of the five largest rivers (the Kymijoki, Kokemäenjoki, Oulujoki, Kemijoki and Tornionjoki) four times a year. In 1990 water samples were also taken from three smaller rivers Porvoonjoki, Vantaanjoki and Karjaanjoki, discharging into the Gulf of Finland, (Fig.l). The sample volumes were about 30 litres.

Samples from two lakes (Inari and Päijänne) and one river (Kemijoki) were taken monthly for tritium analyses (Fig. 1).

2.1.2 Pre-treatment and analyses

To preserve the surface water samples until further treatment, 2 g of solid citric acid were added in the field to each 2—litre sample. The samples were analysed after evaporation to dryness and ashing of the dried samples at 450°C. All samples were analysed gammaspectrometrically.

The germanium detectors used for the analyses in our laboratory are either lithium drifted or high purity crystals with relative efficiencies of between 15% and 39%. The measurements were performed in background shields of 12 cm lead, which are lined with copper (2 mm) or cadmium (1 mm) and copper (0.5 mm) to reduce X- rays from the shields. The measuring times were between 6 and 24 hours. The measurements were made in beakers of cylindrical geometry (volume 30 ml). The

8 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

activity concentrations of the samples were calculated using the computer program GAMMA-83.1516

After gammaspectrometric measurement, the bulked surface water samples were analysed for 89Sr and ^Sr using a method described by Osmond et al.6, which was modified to some extent for surface water. After radiochemical separation, 89Sr and ^Sr were measured together as strontium carbonate. The measurements were made using a low-background gasflow beta counter, Berthold LB 770-1. After a two-week ingrowth period, '"Y, the daughter of '"Sr, was precipitated as Y- oxalate and measured twice to check the purity of the '"Y samples.

The samples for tritium analyses were distilled to dryness to remove impurities. The tritium level was then determined by the electrolytic enrichment method presented by Östlund et al.20, with some modifications.

2.2 Fish

2.2.1 Sampling

The monitoring programme included fish samples taken from four of the largest lakes in Finland (Fig. 3) and from other large lakes of great importance for freshwater fishing. In order to locate the highest concentrations of 137Cs in fish, samples were also taken from small oligotrophic lakes (surface area a few hectares) mainly in the area of high deposition (fallout categories 4 and 5 in Fig. 5)

The total number of fish samples analysed and the number of lakes from which fish samples were taken in the various provinces (cf. Fig. 4) in 1988 - 1990 were as follows:

9 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

Province Number of Number of lakes fish samples analysed

1988 1989 1990 1988 1989 1990

Häme 259 246 248 27 32 30 Central Finland 114 233 99 12 43 10 Kuopio 62 36 41 7 5 4 Kymi 53 51 45 5 7 4 Mikkeli 106 86 100 11 11 10 North Karelia 12 24 13 1 3 1 Oulu 115 64 10 2 3 1 Turku and Pori 114 109 80 10 9 6 Uusimaa 32 34 13 4 9 5 Vaasa 44 12 4 5 2 3 Aland 0 2 3 0 1 1

Total 911 897 656 84 125 75

Results for the province of Lapland and some of those for Oulu are given in reference 11. In calculations for the intake estimations the results given in reference 11 for fishery statistical areas 7 and 8, have, however, been taken into account.

The fish species analysed were those most commonly used for human consumption: perch, pike, vendace, bream, burbot, roach, whitefish, pike-perch and trout. Some samples of silver bream, smelt, dace, eel, ide, ruff and rudd were also analysed. Of these species, perch, pike and vendace each account for more than 20% of the total catch of freshwater fish in Finland. The fishes were of the normal size for edible fish and represent typical catches. The samples even included very small vendace and perch, which are also eaten in Finland. The sample weight was about 1 kg fresh fish. Thus each sample consisted of one or, more usually, several individuals, depending on their size. The sampling times were to some extent affected by the seasons in which different species are caught.

10 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

The fish species sampled, with their Latin and Finnish names, are,w .

FISH SPECIES LATIN NAME (Finnish name)

BREAM (lahna) Abramis brama BURBOT (made) Lota lota DACE (seipi) Leuciscus leuciscus EEL (ankerias) Anguilla anguilla IDE (säyne) Leuciscus idus PERCH (ahven) Perca fluviatilis PIKE (hauki) Esox lucius PIKE-PERCH (kuha) Stizostedion lucioperca ROACH (särki) Rutilus rutilus RUDD (sorva) Scardinius erythrophthalmus RUFF (kiiski) Gymnocephalus cernua SILVER BREAM (sulkava) Abramis ballerus SMELT (kuore) Osmerus eperlanus TROUT (taimen) Salmo trutta VENDACE (muikku) Coregonus albula WHITE BREAM (pasuri) Blicka bjoerkna WHITEFISH (siika) Coregonus lavaretus (col)

Samples were obtained from several sources. Fishery districts, which are under the supervision of the Ministry of Agriculture and Forestry, organized the sampling in each province. The Finnish Game and Fisheries Research Institute also supplied a large number of samples.

2.2.2 Sample treatment

Samples were received by the Centre and preserved deep-frozen for further treat­ ment.

The fish were cleaned and gutted as normally in the kitchen. Big fish were filletted, and their heads, entrails, scales or skin, fins, backbone and other big bones were removed. Only the heads and entrails were removed from small perch, vendace, roach and other small fish. Thus only edible parts were taken for analysis. Some samples, consisting of a large number of fish of different size, were subsampled according to the size of the fish.

11 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

2.2.3 Gamma-spectrometric analyses

The cleaned samples were cut into small pieces and packed into Marinelli beakers with a volume of about 560 ml. If only a small amount of sample was available, a smaller cylindrical beaker (volume 30 ml) was used.

Gammaspectrometric analyses were performed as described in chapter 2.1.2. The measuring times were between 15 minutes and about fifteen hours. The 137Cs con­ centrations in all samples were clearly above the detection limit.

2.2.4 Data treatment

The fish species studied were divided into three groups based on feeding habits: - Predators (e.g. pike, pike-perch, burbot) - Non-predators or benthic feeders (e.g. vendace; bream, roach and other roach- related fish) - Part predators and pari non-predators or intermediate group ( e.g. perch, whitefish)

The lakes in this study were divided into four classes by size:

Class Surface area Number of lakes 1988 1989 1990

1 >890km2 4 4 3 2 20-890 km2 30 30 23 3 1-20 km2 29 45 27 4 <1 km2 21 42 21

The first class comprised four of the largest lakes in Finland: Saimaa, Päijänne, Kallavesi and Oulujärvi (Fig. 3).

Though the lowest size limit of the second class was 20 km2, the area of most of the lakes in this class (class 2) exceeded 100 km2. The third class comprised lakes with an area of 1 to 20 km2 (class 3). Although of minor importance in terms of fishing, most of the lakes with a surface area of less than 1 km2 (class 4) were oli— gotrophic. Such lakes exhibit the maximum radionuclide contents in freshwater fish.

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2.2.5. Areal averages of 137Cs in fish and intake via fish

Statistical fishery areas 1-7 correspond roughly to drainage basins 1-7, whereas statistical fishery area 8 corresponds to drainage basins 8, 9, 10 and 11 (cf. Figs. 2 and 3). The division of the fish into three groups was based on their feeding habits. The catches of each fish group in each statistical fishery area were calculated from the information on catches of each species belonging to the group. Both recreation, subsistence and professional fishing were taken into account. The catch statistics used for the calculations were from 1986 (recreational and subsistence fishing) and from 1988 (professional fishing)5,7"9.

The annual average concentrations of 137Cs in freshwater fish and in the three fish groups were calculated countrywide and in the eight fishery areas. The average concentrations of 137Cs for each of the three groups were used in each fishery area. In fishery areas 4 and 5, the average concentrations of 137Cs for the three fish groups were calculated using the estimate that lakes with a surface area of more than 20 km2 accounted for 90% and that lakes with a surface area of less than 20 km2 accounted for 10% of the total catch of the fishery area.

The intakes of 137Cs via freshwater fish (I) in 1988, 1989 and 1990 were calculat­ ed as before 13 using the following equation:

1 8 3 I = 7 x C x T 2 2 A,; x m, • M i=l j=l '' ''

where M = total annual catch of freshwater fish5,7"9 (kg) C = daily average consumption of cleaned fish per person (kg d-1) T = time period (d) A; j = activity concentration of 137Cs in fish group j in fishing area i (Bq kg"1) iti; j = catch of fish in fish group j in fishing area i5,7"9 (kg)

2.2.6 Transfer of 137Cs from water to fish

The annual average concentrations of 137Cs in water in the eight large fishery statistical areas (cf. Fig.3) were calculated from the results of this report and those of references 12 and 14. The contents of 137Cs in fish for 1986 and 1987 were

13 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

taken from references 13 and 14. Transfer factors were calculated by dividing the annual average concentrations in all fish, and in the three fish groups, weighted for catches, in each of the eight areas, by the annual averages in water in the same areas. The same factors were also calculated for the whole country using the countrywide annual average concentrations in all fish and in the three fish groups, weighted for catches, and the annual arithmetic mean value of 137Cs in surface water in Finland.

2.2.7 Transfer of Cs from Chernobyl deposition to fish

The average depositions of 137Cs in the eight large drainage basins were calculated using the average 137Cs depositions in different municipalities2 in each of the eight drainage basins. Transfer factors from the Chernobyl deposition to edible fish were calculated by dividing the average concentrations of 137Cs in fish and in the three fish groups, weighted for catches, in each drainage basin, by the average deposition in the same drainage basin. The transfer factors were also calculated for the whole country using the countrywide mean depositon of 137Cs and the countrywide averages of 137Cs in all fish and in the three fish groups, weighted for catches. The concentrations of 137Cs in fish in 1986 and 1987 were taken from references 13 and 14.

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3 RESULTS

3.1 Surface water

The dominant gamma-emitting radionuclide was 137Cs, which was detected in all 134 the samples. The amounts of the shorter-lived cesium isotope, Cs (Tw = 2.1 y), in some samples from the areas of low deposition were below the detection limit in 1989. In addition to these radionuclides, lzsSb and 106Ru occurred in some samples in 1988. In 1989 and 1990 106Ru was no longer detectable (Tables I - IX). Of the beta-emitting radionuclides, '"Sr was detected in all the samples analysed, while 89Sr, a shorter-lived strontium isotope (T^ = 50.5 d), could no longer be detected.

In March 1988, the concentrations of 137Cs ranged from 9 to 300 Bq m~3 in different watercourses or their subrcgions. The highest concentrations of 137Cs were found in subregion a of the drainage basin of the Kymijoki (300 Bq m"3) and in sub- region b of the drainage basin of the Kokemäenjoki (280 Bq m"3). The activity concentrations of 137Cs decreased to 120 and 140 Bq m~3 in October 1990 (Tab­ les I - IX). The contents of 137Cs were lowest in the samples from the drainage basins of the Kemijoki and Tornionjoki and from the drainage area of the rivers in northern Finland discharging into the Arctic Ocean. Changes in the activity concentrations of 137Cs after the Chernobyl accident in the subregions of the four large drainage basins are presented in Fig. 6. The concentrations of 134Cs were about 14% of those of 137Cs at the end of 1990.

Of the other gamma-emitting radionuclides, 125Sb was detected in many samples from the main deposition area (marked with a dotted line in Fig. 2) in 1988. The highest activity concentrations of lzsSb during this study period were detected in March 1988 (17 Bq m"3). In 1990, 125Sb was detected in only a few samples and in low concentrations (Tables VIII - IX). The detection limits depend on factors such as sample volume and measurement time, but are on average 6 and 20 Bq m"3 for 125Sb and 106Ru, respectively.

The activity concentrations of ^Sr were much lower than those of 137Cs, ranging from 5 to 30 Bq m"3 and from 5 to 20 Bq m"3 in March 1988 and May 1990, respectively. The concentrations were highest in the Kymijoki and Kokemäenjo­ ki drainage basins and in the Sotkamo water course in the Oulujoki drainage basin (Tables I - IX). A slight decrease in the activity concentrations of'"Sr was recorded during these three years in different drainage areas.

Between March 1988 and March 1990 the 137Cs contents in the water of the five rivers (the Kymijoki, Kokemäenjoki, Oulujoki, Kemijoki and Tornionjoki) de-

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creased by 40 - 70%. A decrease of 3 - 40% in the abundances of '''Sr was also noticed during the same period (Tables X - XII) in the same rivers. The mean annual 137Cs and ^Sr concentrations in these rivers are compared in Figs. 7 and 8. Clear differences in the activity concentrations of 137Cs in the three smaller rivers (the Porvoonjoki, Vantaanjoki and Karjaanjoki, sampled in 1990, were noticed (Table XIII). Each of them had lower activity concentrations of 137Cs than the Kymijo­ ki, which also flows into the Gulf of Finland but through a larger and more con­ taminated drainage area than the smaller rivers. In Porvoonjoki and Vantaanjoki contents of radiocesium in October were much higher than those in March, May and August.

The activity concentrations of 3H in surface water were low. The annual mean concentrations in the Kemijoki, Lake Päijänne and Lake Inari were 4.4 ± 0.8, 4.0 ± 0.8 and 4.0 ± Ö.4 kBq m"3, respectively, in 1988, and at almost the same level in 1989 (Table XIV).

3.2 Fish

3.2.1 Radionuclide contents

The radioactive substances detected by gammaspectrometric measurements on freshwater fish are the two cesium isotopes 134Cs and 137Cs. Studies on fish from Finnish Lapland are given and discussed in detail in another report ".

The average concentrations of 137Cs in fish from individual lakes in classes 1-3, which are listed by province, are given in Tables XV - XVII, XIX - XXI and XXIII - XXV for the three years, respectively. As can be expected from the areal distri­ bution of the 137Cs deposition from Chernobyl (Fig. 5), the highest concentrations of 137Cs were detected in the provinces of Häme and Central Finland.

In class 1 and class 2 lakes the average concentrations of 137Cs in fish ranged from 19 to 6600, from 5 to 9900 and from 13 to 3900 Bq kg'1 in 1988, 1989 and 1990, respectively (Tables XV - XVI, XIX - XX and XXIII - XXIV). The variation in class 3 lakes was from 3 to 20 000, from 14 to 14 000 and from 4 to 7000 Bq kg" 1 in 1988, 1989 and 1990, respectively (Tables XVII, XXI, XXV).

The average concentrations of 137Cs in individual fish species from class 4 lakes are given by province in Tables XVIII, XXII and XXVI for 1988, 1989 and 1990, re­ spectively. The oligotrophic lakes in this class represent the conditions of maximum accumulation of 137Cs in fish. The highest 137Cs value in fish during these three years was found in a pike sample (26 000 Bq kg"1) from a small oligotrophic lake in the area of highest deposition (Fig. 5) in 1988 (Table XVIII).

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The variation in the activity concentrations of 137Cs in fish was greatest in drain­ age basin 5, where the highest values were almost five times the quarterly average (Fig. 9).

The contents of 137Cs in fish still show an association with the 137Cs deposited in the area, increasing with the abundance of 137Cs deposited. The predator group had higher 137Cs concentrations than the intermediate group, and non-predators had the lowest values in 1988 - 1990. The intermediate group reached its maximum in 1987 and the predator group in 1988, while contents of 137Cs in non-predators already started to decrease in 1986 (Fig. 10). The information in fig. 10 is based on the large amount of samples in each deposition area, though the lakes and the number of samples in different groups are not necessarily the same each year. The variation in the activity concentrations of 137Cs in a certain fish species is large in each deposition area. An example of the variation and of the typical number of samples in different deposition categories is given in Fig. 11.

In addition, concentrations of 137Cs in a certain fish species or in the three fish groups (predators, non-predators and intermediate) are highest in smallest lakes by surface area (class 4) in deposition area 4+5 (cf. Fig. 5). Class 1 and class 2 lakes no longer differ from each other, but 137Cs in fish in class 3 lakes is somewhat higher. Contents of 137Cs in fish in class 1-3 lakes and in class 4 lakes are compared in Fig. 12. The dependence of 137Cs in fish on the size of the lakes is not seen clearly in the areas of slighter contamination (areas 1 and 2+3).

An example of temporal and other variations in the abundances of 137Cs in the fish of one lake is given in Fig. 13. Differences between fish species have decreased, but predatory fish still have somewhat higher amounts than the others.

The amount of radioactive cesium in fish depended on the size of the fish. This was mainly studied on perches in small lakes (class 4) in the area of high deposition (area 4+5). In 1986, the smaller the fish the higher were the concentrations of radio­ active cesium. In 1987, the situation began to change, and since 1988 the activity concentrations of 137Cs ir? perch have been higher in bigger fish than in smaller ones (Fig. 14).

3.2.2 Areal averages of Cs in fish and intake via fish

The most important area of freshwater fishing in Finland is drainage basin 3, which accounts for somewhat more than 30% of the total catch. Drainage basins 4 and 5 are the next most important, representing about 18% and 15% of the total catch, respectively. Coastal areas 1, 2 and 6 account for 4-7% of the total catch from freshwater fishing.

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The annual average concentrations of 137Cs in the three fish groups in different statistical fishery areas are given in Table XXVII. The countrywide annual averages of the three fish groups, weighted for catches, are also given in Table XXVII. The average concentrations of 137Cs in the whole catch of fish in different areas and in the whole country, obtained as an intermediate result when calculating intakes with the formula given in chapter 2.2.5, are given in Table XXVIII. The average concentrations were highest in statistical fishery areas 4 and 5, being 1500 and 1400 Bq/kg in 1988, respectively. Those values then decreased, being in 1990 only 55% of the values in 1988. The countrywide averages decreased from 840 in 1988 to 470 in 1990.

The average intakes of 137Cs via freshwater fish countrywide were about 3700, 2400 and 2000 Bq in 1988, 1989 and 1990, respectively, when the average consumption of 4.1 kg a": cleaned freshwater fish per person and the average contents of 137Cs, given in Table XXVIII, are used.

3.2.3 Transfer of l31Cs from water to fish

Transfer factors from water to fish in the eight fishery statistical areas, which are also the eight large drainage basins, varied greatly. In 1986, when the activity concentrations of 137Cs in fish had not yet significantly increased, the transfer factors ranged from 200 to 1900, being highest in non-predatory fishes. Four years after the Chernobyl accident, transfer factors ranged from 2300 to 30 000, in different areas, being highest in predatory fishes (Table XXIX).

3.2.4 Transfer of 137Cs from Chernobyl deposition to fish

Transfer factors from deposition to fish ranged from 0.012 to 0.064 rrrVkg in different areas and groups in 1986. The highest transfer factors from deposition to fish were about 0.2-0.3 m2/kg in 1987-1989. This means that 20-30% of the amount of I37Cs deposited in one m2 was transferred to one kg of fish. In the whole country, the transfer of 137Cs from deposition to fish was 12% at its maximum in 1987-1988 (Table XXX).

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4 DISCUSSION

4.1 Surface water

The amount of 137Cs remaining in drainage basins in October 1990 varied greatly in different water courses, being 1 - 20% of the amounts in May 1986. The concentrations of 137Cs had decreased most in the Kokemäenjoki and Kymijoki drainage basins. The high proportion of clay in the catchment area of the Koke­ mäenjoki and to a less extent in that of the Kymijoki restrains cesium effectively. In the Oulujoki drainage basin less 137Cs was removed from water. In October 1990, some 9 - 20% of the amounts of 137Cs present in May 1986 still remained. This is an area of rather extensive bogs and virtually no clay soils. The organic material and humic substances of the bogs retain cesium better in the water phase in this drainage area than in the Kokemäenjoki and Kymijoki drainage basins. 137Cs is also more easily leached from a catchment area rich in organic material and humic substances than from clay areas where leaching is negligible.

The concentrations of 137Cs in the mouths of the rivers carrying water from catch­ ment areas to the Baltic Sea has also decreased significantly, being in October 1990 only 4-7% of the maximum contents in May 1986, except in the Oulujoki, where it was 16%. Great amount of resuspended surface layer of sediment could explain the higher contents of 137Cs in Porvoonjoki and Vantaanjoki in October.

Before the accident, the ratio of 137Cs to ""Sr in surface waters was below 0.5.1S This ratio increased by a factor of about 100 in the main deposition area and by about 10 in the area of lowest fallout.12 In March 1987, this ratio ranged from 3 to 6014 and in October 1990 from 0.9 to 7.4 in different drainage areas, thus gradually approaching the value of the situation of slow changes. The changes over time in this ratio reflect the different behaviour of these two radionuclides in the aquatic environment. Cesium is effectively removed from the water phase by settling to the bottom, while strontium remains better in the water phase. The different change in this ratio in different drainage basins reflects the impact of the runoff area on the behaviour of the two radionuclides. Runoff areas with a high content of clay effectively restrain radiocesium, whereas those with large expanses of bog with ample humic material retain radionuclides more effectively in a more mobile form.

4.2 Fish

The greatest source of variation in the activity concentrations of radiocesium in fish in different provinces and drainage basins is the areally uneven distribution of radiocesium deposition. The variation in the radiocesium contents of fish in the

19 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94 same deposition area is due to the different chemical and hydrological charac­ teristics of the lakes and quality of their drainage basins, and to local differences in the amounts of radiocesium deposited within each deposition category.

In a deposition area the abundances of cesium are highest in the smallest lakes (class 4). In these lakes the amounts of cesium deposited are diluted less than in large lakes, and the proportion of runoff is higher than in large lakes. Moreover, most of the small lakes in this material are oligotrophic, thus representing conditions of maximum accumulation of radiocesium in fish. The flow rate and residence time of the water in a lake also affect the transport of radiocesium to fish, causing differences between lakes even when the deposition in the lakes is otherwise the same.

In a lake, the feeding habits of fish affect their radiocesium level. This causes variations between different fish species with different feeding habits and between different sizes of fish of the same species. In one lake the activity concentrations of 137Cs in different fish species may vary by a factor of 4 - 5 and in different samples of the same species by a factor of 2 - 3 (cf. Fig. 13).

The reliability of intake estimations is based on the fairly large sample material, which represented different accumulation conditions. One source of uncertainty is the fact that the catch statistics of different areas are not from the same year as the results for radiocesium, although there should not be big variations in the catches of different years.

The intake via fish was highest in the second year after the accident. The relative contribution of fish to the total annual intake via foodstuffs has increased continu­ ously since 1986, because the cesium contents of agricultural products have decreased much more rapidly than those of natural products such as fish, mushrooms and wild berries10,17. The countrywide average intake via freshwater fish was almost the same in 1990 as in 1986. In 1990 it was somewhat less than half of the maximum value in 1987. The variation in the 137Cs intake via freshwater fish is large in different areas owing to the marked variation in the activity concentrations of fish from different lakes and different parts of Finland.

The estimations of areal transfer factors of 137Cs made here are rough, but give the order of magnitude for different fish groups. The transfer of 137Cs from water to fish can be estimated more exactly using water and fish values from the same lake. Then the variation caused by environmental factors would also be recognized. The areal transfer factors from deposition to fish are most reliable in drainage areas 4 and 5, where the highest number of fish samples was taken.

20 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Bulletins containing recommendations on using fish as food were still issued by the Finnish Centre for Radiation and Nuclear Safety. In 1988, people living in deposi­ tion areas 2 - 5 in Fig. 5 were advised not to eat fish as their main course more than 2-3 times a week. The recommendation was mitigated in 1989 to concern only perches and predatory fishes in deposition areas 4 and 5. No restrictions for the use of non-predatory fishes as vendace and roach related fishes were needed any more. Recommendations on using fish as food were the same in 1990.

21 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

ACKNOWLEDGEMENTS

Thanks are due to the National Board of Waters and Environment and to other institutions that helped us to obtain water samples. We are grateful to the personnels of Fishery Districts of Central Finland, Häme, Kuopio, Kymi, Mikkeli, North Karelia, Oulu, Turku and Vaasa, and the Ministry of Agriculture and Forestry for organizing sampling of fish and for all the persons who collected and sent the samples for us. Thanks are also due to the Finnish Game and Fisheries Research Institute for supplying a large number of fish samples.

Special thanks are due to Ms Pirkko Saira, Ms Ulla Yli-Arvo and Ms Seija Timonen who treated the water samples and performed radiochemical ^Sr ana­ lyses. Thanks are also due to the persons working in the gamma laboratories of the Surveillance Department for performing the gammaspectrometric analyses of the samples.

We are also indebted to the Head of the Laboratory for Radionuclide Monitoring, Matti Suomela, and to the Head of the Fallout Section, Aino Rantavaara, for their valuable comments.

22 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

REFERENCES

1. Analyysituloksia virtahavaintopaikoilta v. 1970. Helsinki: National Board of waters, Finland, 1973; report 45. (In Finnish)

2. Arvela H, Markkanen M, Lemmelä H. Mobile survey of environmental gamma radiation and fall-out levels in Finland after the Chernobyl accident. Radiation Protection Dosimetry Vol. 32, No 3, 177-184 (1990).

3. Atlas of Finland, Folio 132. Water. Helsinki: National Board of Survey, Geographical Society of Finland, 1986.

4. Atlas of Finland, Folio 232-233. Agriculture-special branches, fisheries. Helsinki: National Board of Survey, Geographical Society of Finland, 1980.

5. Leinonen K, Lehtonen H, Hilden M. Virkistys- ja kotitarvekalastus Suomessa vuonna 1986. (Abstract: The profitability of professional fishing in Finland in 1986.) Suomen kalatalous 58 (13-17) 1991.

6. Osmond RG, Owers MJ, Healy C, Mead AP. The determination of radioactivity due to caesium, strontium, barium and cerium in waters and filters. Harwell, 1959; AERE-R 2899.

7. Partanen H, Parmanne R, Tuunainen A-L, Ammattikalastus Suomessa vuonna 1986. (Abstract: Professional fishing in Finland in 1986.) Suomen kalatalous 58 (1-12) 1991.

8. Partanen H, et ai, Ammattikalastus Suomessa vuonna 1987 (Manuscript).

9. Partanen H, et ai, Ammattikalastus Suomessa vuonna 1988, unpublished.

10. Rantavaara A. Radioactivity of foodstuffs in Finland in 1987 and 1988. Helsinki: Finnish Centre for Radiation and Nuclear Safety, 1991; STUK- A78, Supplement 4 to Annual Reports STUK-A74 and STUK-A89.

11. Rissanen K. et ai, Radioactivity in reindeer, game, fish and plants in Finnish Lapland in 1987-1990. Helsinki: Finnish Centre for Radiation and Nuclear Safety, 1991; supplement to Annual Reports STUK-A74 and STUK-A89. (will be published).

12. Saxen R, Aaltonen H. Radioactivity of surface water in Finland after the Chernobyl accident in 1986. Helsinki: Finnish Centre for Radiation and Nuclear Safety, 1987; STUK-A60, supplement 5 to Annual Report STUK-A55.

23 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

13. Saxen R, Rantavaara A. Radioactivity of fresh water fish in Finland after the Chernobyl accident in 1986. Helsinki: Finnish Centre for Radiation and Nuclear Safety, 1987; STUK-A61, supplement 6 to Annual Report STUK-A55.

14. Saxen R, Radioactivity of surface water and freshwater fish in Finland in 1987. Helsinki: Finnish Centre for Radiation and Nuclear Safety, 1990; STUK- A77, supplement 3 to Annual Report STUK-A74.

15. Sinkko K. Computer analysis of gamma-ray spectra in sample measurements. Licenciate Thesis. Helsinki: University of Helsinki, Department of Physics, 1981. (In Finnish)

16. Sinkko K, Aaltonen H. Calculation of the true coincidence summing correction for different sample geometries in gamma-ray spectroscopy. Helsinki: Finnish Centre for Radiation and Nuclear Safety, Surveillance Department, 1985; STUK-B-VALO 40.

17. Suomela M, Blomqvist L, Rahola T, Rantavaara A. Studies on environmental radioactivity in Finland in 1987. Helsinki: Finnish Centre for Radiation and nuclear Safety, 1991; Annual Report STUK-A74.

18. Studies on environmental radioactivity in Finland 1984-1985. Helsinki: Finnish Centre for Radiation and Nuclear Safety, 1987; Annual Report STUK- A54.

19. Varjo M. Kalannimiluettelo (List of Finnish fish names). Luonnon Tutkija 85 (supplementary number): 1-60, Suomen Biologian Seura Vanamo r.y., 1981.

20. Östlund HG, Werner E. The electrolytic enrichment of tritium and deuterium for natural tritium measurements. In: Tritium in the physical and biological sciences. Vienna: International Atomic Energy Agency, 1962; 95-104.

24 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

205 25s 30^

Fig. 1. Sampling points of lake and river systems (•), and at the mouths of the five largest rivers discharging into the Baltic Sea:

I Kymijoki III Oulujoki V Tornionjoki II Kokemäenjoki IV Kemijoki,

and at three rivers discharging into the Gulf of Finland:

1 Porvoonjoki 2 Vantaanjoki 3 Karjaanjoki and sampling stations for tritium determinations: A Lake Päijänne (Kalkkinen), B Kemijoki, C Lake Inari (Nellimö).

25 Fig. 2. Drainage basins with their subregions or watercourses: ;> 3 1. Small rivers discharging into the Gulf of Finland 2. Small rivers discharging into the Archipelago Sea 3. Vuoksi drainage basin a Pielisjärvi subregion b Kallavesi subregion c Saimaa 4. Kymijoki drainage basin 00 a Keitele - Päijänne b Päijänne c Päijänne - Gulf of Finland 5. Kokemäenjoki drainage basin a Längelmävesi, Hauho and Vanaja watercourses b Ähtäri and Keuruu watercourses, Palovesi- Pyhäjärvi c Pyhäjärvi - Rautavesi, Ikaalinen watercourse Kokemäenjoki and Loimijoki basins 6. Rivers discharging into the Gulf of Bothnia 7. Oulujoki drainage basin a Hyrynsalmi watercourse b Sotkamo watercourse c Oulujärvi - Gulf of Bothnia 8. Kiiminginjoki, Iijoki and Simojoki rivers 9. Kemijoki drainage basin 10. Tornionjoki drainage basin 11. Rivers discharging into the Arctic Ocean CO Shaded area inside the dotted lines indicates the ^ main fallout area. 1 > VO FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Fig. 3. The statistical fishery areas (num­ bers 1-8 in circles) in Finland with the large lakes: l=Saimaa 2=Päijänne 3=Kallavesi 4=Oulujärvi

w

LAPLAND /

6

/ OULU ^ «."•

/JIKUOPIOLORTX rVAASA JRALS /KARELIA* 62* •. FIN- T~\/\ /

/pORI> HAME^a, / ALAND Fig. 4. The provinces <5 rösi- 22.- S*- K. in Finland. AA-*0 50 »0 22* 26* FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

r -\ OJ:;-.\

,--\ • -^ / \

Cs-137 deposition 1.10.1987

Deposition v^-^X^ ^rvf-* \ kBq/nT area 0- 6 1 6-11 2 11-23 3 23-45 4 45-78 5

Fig. 5. The distribution of 137Cs in Finland after the Chernobyl accident. The municipalities are divided into five categories according to their average 137Cs deposition.2

28 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Bq/l

OULUJOKI DRAINAGE BASIN ©- -O HYRYNSALMI

JAN86 JUL86 JAN81 JUL.81 JAN88 JUL88 JAN89 JUL89 JAN90 JUL90

Fig. 6. The activity concentrations of 137Cs in bulked surface water samples (Bq/1) in subregions or watercourses of four large drainage basins in Finland in 1986-1990.

29 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

Bq/l iO.OOOj

137 CS — KYMIJOKI i.000 — KOKEMÄENJOKI

i 0.100, »-- r

0.010,

0.001 ~i—i—i—i—|—i—i—i—r

10.000

137 CS — OULUJOKI 1.000 —• KEMIJOKI — TORNIONJOKI

0.100,

0.010,

0.001 —i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—r

I960 1965 1970 1975 19B0 19B5 1990 1995

Fig. 7. The annual mean concentrations of 137Cs (Bq/1) in water from the rivers Kymijoki, Kokemäenjoki, Oulujoki, Kemijoki and Tornionjoki in 1964- 1990.

30 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Bq/l 10.000 go sr — KYMIJOKI 1.000^ — KOKEMÄENJOKI

0.100

r-1—"

0.010^ i—

0.001 -j—i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—f"

10.000?

90 Sp — OULUJOKI 1.000 — KEMIJOKI ~ TORNIONJOKI

0.100^

0.010 *-•==*+-* ">^*-.==

0.001"]—i—i—i—s—|—i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—i—|—i—i—i—i—i—i—i—i—r

I960 1965 1970 1975 1980 19B5 1990 1995

Fig. 8. The annual mean concentrations of ^Sr (Bq/1) in water from the rivers Kymijoki, Kokemäenjoki, Oulujoki, Kemijoki and Tornionjoki in 1964- 1990.

31 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

BO/KG

STATISTICAL FISHERY AREA 3 20000

PERCH

10000 PIKE VENDACE

n* l<-^ ~- Im fefa \\

STATISTICAL FISHERY AREA I 20000

10000

o. (j: o: 114a % IL li oft- <>- Ibl» sPl -T fe £0000 rr STATISTICAL FISHERY AREA 5

30000

20000

10000

o: (j: 5 • ( ) • o (5: ft ifei- ** Nili . U_l_ I5t JL&. JAN86 JUL86 JAN8T JUL8T JAN88 JUL88 JAN89 JUL89 JAN90 JUL90 JAN91

Fig. 9. The quarterly average concentrations with variations in 137Cs (Bq kg"1 fresh weight) in perch, pike and vendace in the three most important statistical fishery areas (3, 4 and 5) in Finland in 1986 - 1990.

32 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Bq/kg 8 B 5 000- ^081 4'oo8i PREDATORS 1986 NON- PREDATORS 1986 INTERMEDIATE 1986

4000' 4000 ' 4 000' 3 000 3000' 3000- • 2 000 200O - 2 000- m I 1000 100 0 _| 1000 n H 0 0 0 1 2+3 4 + 3 1 H JS 1— la W DEPOSITION C*T[CO«1 DEPOSITIO1 2-1-N 3 CATEGOR4 -»S Y DEPOSITIO1 1-N 3 CATCGOR4+5 Y

B 0/k i q / k g -*%tt ^008 1 4 000 PREDATORS 1987 NON-PREDATORS 1987 INTERMEDIATE 19S7

400 0 JUU

300' B| 300 0 JOO 99

20OO i 1000 I

2-3 4.S '"Lal DC POS 1 T ION CATEGORY •°:LJUI DCPQSiTiON C*UC0R1 DEPOSITION C»TCCO*T I a / k g B q/k g Bq/1.9 3 000 5 000 PREDATORS 1986 NON- PREDATORS 1988 INTERMEDIATE 19B8

4 000-

3000 •

2000 -

10OO

2*3 l»S D E POS I T ION C AT C COW

B q/ k g B 4000 • iu08l "I'ouSl PREDATORS 1989 NON- PREDATORS 1989 INTERMEDIATE 1989

4 000- 400 0 4 000 3000 • 3000 • 3000 2O0O 2000 2000 - • 1000 -uni 10OO • 1000- 1 2+3 4+5 1 2 + 3 4 + S _1 J2+3 4+ 5 DEPOSITION CATEGORY DEPOSITION CATEGORY DEPOSITION CATEGORY

i q/ k g 'irSoSi SOOO PREDATORS 1990 NON- PREDATORS 1990 INTERMEDIATE 1990

4000

3000 • JUU

300' IM 2000 HB

l 1 000 1 900- BB DOO ••

1 2 + 3 4+ s t 2+3 4+5 oi •_•- DEPOSITION CATEGORY DEPOSITION C A TECORt 1 2+3 4+5 DEPOSITION CATEGORY Fig. 10. The average annual concentrations of 137Cs (Bq kg"1 fresh weight) in the three fish groups: predators, non-predators and intermediate, in depo­ sition areas 1, 2+3 and 4+5 (cf. Fig. 5) in 1986, 1987, 1988, 1989 and 1990.

33 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

B

25000 5000 20000

20000 £000

15000 21

15000 3000

10000

10000 2000

5000 5000 1000 ^6 4£ ss 12 11 - 13 ^^^^ 1 2+3 £+5 1 Ml2+3 i+^5 •j;p1 2+3 a£+5

Fig. 11. The average annual concentrations of 137Cs with variation ranges (Bq kg"1 fresh weight) in perch, pike and vendace in deposition areas 1, 2+3 and 4+5 (cf. Fig. 5) in 1988. Numbers of samples, included in each column, are also given.

34 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

B g / k < 6 O OC

PREDATORS LAKE CLASS

^

^ ^g. n 1 2+34+5 t 2 * 3 4 + 5 1 ,n2+3 4 ., S DEPOSITION CATEGORY •- 1 9 B 8 -" >- 19 89 -> >- 1990 YEAR

> o / k o 6 000 1-f NON— PREDATORS LAKE CLASS

1 1 T-3 R^?a *

^ SSSK> ,—, r°*i ^^; 2 + 3 4 + 5 1 2 + 3 4 + 5 1 2+3 4+5 DEPOSITION CATEGORY I 9 88 -" •- 19 8 9 -> I-1990-1 YEAR Bi^ol

INTERMEDIATE LAKE CLASS

^••••^ Pssq | | 1 n2 + 3 4 + 5 1 2+3 4+5 DEPOSITION 1 2 »3 4 + 5 CATEGORY 1 •- 19 88 - >- 19 89 -> I-1990- YEAR

Fig. 12. The average annual activity concentrations of 137Cs (Bq kg"1) in the three fish groups in lakes, classified according to size into two categories: > 1 km2 (lake classes 1-3) and < 1 km2 (lake class 4), in areas of different deposition: 1, 2+3 and 4+5 (cf. Fig. 5), in 1988-1990.

35 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

BO/K G 5000

F I SH 4000- BURBOT PERCH DO PIKE PERCH VENDACE 3000-

Pl KE 2000

1000-

JUL86 JAN87 JUL87 JAN88 JUL88 JAN89 JUL89 JAN90 JUL90 JAN91

Fig. 13. Temporal variation in 137Cs in different fish species in Kyrösjärvi, a large lake (area about 100 km2) in deposition area 4+5 (cf. Fig. 5) in 1986 - 1990.

B q / k 1 O O 8

7 0 0 0

6 0 0 0-

5 0 0 0

4 0 0 0:

3 0 0 0

2 0 0 0 19 8 7 19 8 8 19 8 9 19 9 0

Fig. 14. Change in the annual averages of 137Cs (Bq kg"1) in perch, classified ac­ cording to size into three classes: <15 cm, 15-20 cm and >20 cm, in small lakes (class 4) in deposition area 4+5 (cf. Fig. 5) in 1986 -1990. The number of samples in each size class each year is also given.

36 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

90 Sr and gaieaa-enitting radionuclides In the surface water of soae drainage baalna and their aubreglona and In groups of rlvera discharging Into different sea areas in March 1986 (Bq/m ). The resulti are decay corrected to the sampling date. The figures in brackets refer to the number of the drainage basin, and (a). (b) or (c) refer to the subregion (cf. Fig. 2).

RIVERS DISCHARGING INTO THE GULF OF FINLAND (1)

RIVERS DISCHARGING INTO THE ARCHIPELAGO SEA 12) 14

VUOKSI (3) Pielisjärvi subregion (a) 14 0 3. 1 10 38 Kallavesi subregion lb) 17 5.7 1. 8 14 44 Saimaa (c) 17 0 0 20 83

KYMIJOKI (4) Keitele-Paijanne (a) 26 16 11 93 300 Päijänne (b) 23 0 12 44 150 Pai Janne-Cu If of Finland (c) 25 i: 11 B2 240

KOKEMÄENJOKI (5) Längelmävesi. Hauho and Vanaja watercourses (a) 27 36 17 26 B3 fthtäri and Keuruu watercourses. Pal ovesi-Pyhäjärvi (b) 26 21 14 92 280 PyhaJärvi-Rautavesi. Ikaalinen watercourse. Kokemäenjoki and Loimijoki basins {c} 31 23 15 68 210

RIVERS DISCHARGING INTO THE GULF OF BOTHNIA (6) 15 9.6 4 ,1 30 94

OULUJOKI (7) Hyrynsalmi watercourse (a) 9.3 7.6 24 Sotkamo watercourse (b) 30 54 170 OuluJärvi-PohJanlahti (c) 19 16 47

KIIMINGINJOKI. IIJOKI AND SIMOJOKI (8) 9.1 5.6 22

KEMIJOKI (9)

TORNIONJOKI (10) 9.2 13

RIVERS DISCHARGING INTO THE ARCTIC OCEAN (11)

below the detection limit FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

Sr and gaaaa-ealttlng radionuclides in the aurface vattr of aoac drainage baaina and their subreglona and in groupa of rivers dlacharging into different aea areaa in Mar 198B (Bq/m ). The reaulta are decay corrected to the sampling date. The figurea in bracketa refer to the number of the drainage baain. and (a), (b) or tc) refer to the aubregion (c(. rig. 2).

RIVERS DISCHARGING INTO THE GULP OP FINLAND (1)

RIVERS DISCHARGING INTO THE ARCHIPELAGO SEA (2)

VUOKSI (3) Pieliajarvl aubregion (a) 11 O O 7.7 29 Kallavesi aubregion (b) 16 12 4.2 24 80 Saimaa (c) 13 O O 16 50

KYMIJOKI (4) Keltele-Pkijanne (a) 27 7.5 68 220 Paijanne (b) 22 O 6.9 36 120 Paijanne-Gulf of Finland (c) 28 25 9.2 67 220

KOKEMXENJOKI (5) Langelmaveai. Kauho and Vanaja vatercouraes (a) 22 77 Xhtari and Keuruu watercourses. Paloveei-Pyhajarvi (b) 77 250 Pyhajarvi-Rautaveai, Ikaalinen watercourae. Kokemäenjoki and Loimijoki basins (c) 54 170

RIVERS DISCHARGING INTO THE GULF OF BOTHNIA (6) 70

OULUJOKI (7) Hyrynsalmi watercourae (a) 15 0 8.0 22 Sotkamo vatercourae (b) 24 0 46 160 Oulujarvi-Pohjanlahti (c) 16 0 13 41

KIIMING1NJOKI. IIJOKI AND SIMOJOKI (8)

KEMIJOKI (9)

TORNIONJOKI (10)

RIVERS DISCHARGING INTO THE ARCTIC OCEAN (11)

below the detection Unit

38 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Table III Sr and gamm.a-eal11Ing radionuclides In the surface water of some drainage basins and their aubreglons and In groups of rivers dlacharglng Into different •ea ireas In August 1980 (Bq/m ). The results are decay corrected to the sampling date. The l'lgures In brackets refer to the number of the drainage basin, and (a), (b) or (c) refer to the aubreglon (cf. Fig. 2).

RIVERS DISCHARGING INTO THE GULF OF FINLAND (1)

RIVERS DISCHARGING INTO THE ARCHIPELAGO SEA (2)

VUOKSI (3) Pielisjärvi subreglon (a) 12 0* 2.1 6.9 29 Kallavesi subreglon (b) 20 0 2.0 27 94 Saimaa (c) 16 0 4 .0 16 57

KYMIJOKI (4) Keitele-Paijanne (a) 30 0 8.4 76 260 PalJ anne (b) 24 0 5.9 55 190 Päijanne-Gulf of Finland (c) 19 16 6.6 62 220

KOKEMÄENJOKI (5) "Längelmävesi, Hauhci and Vanaja watercourses (a) 28 0 12 30 89 Ähtäri and Keuruu watercourses. Pa lovesi-pyhäjärvi (b) 25 0 8.4 73 260 Pyhäjärvi-Rautavesi. Ikaalinen watercourse, Kokemäenjoki and Loimijoki basins {c) 24 37 14 51 180

RIVERS DISCHARGING INTO THE GULF OF BOTHNIA (6)

OULUJOKI (7) Hyryncalmi watercourse («) 15 5.7 25 Sotkamo watercourse (b) 23 42 160 Oulujarvl-Pohjanlahtl (c) 20 8.5 34

KIIMlNGlNJOKI. IIJOKI AMD SIMOJOKI [8)

KEMIJOKI (9)

TORNIONJOKI (10)

RIVERS DISCHARGING INTO THE ARCTIC OCEAN (11) 9.7

below the detection limit

39 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

Sr and gaama-emitting radionuclldaa In the aurface water of loie drainage baaina and their aubregiona and in well aa groups of rlvera diacharging into different aea araaa in October lgSS (Bq/tn ). The reiulta are decay corrected to the sampling data The flgurea in bracket! refer to the number of the drainage baaln. and (a), (b) or (c) refer to the aubregion (cf. Fig. 2).

13«,

RIVERS DISCHARGING INTO THE GULF Or FINLAND (1)

RIVERS DISCHARGING INTO THE ARCHIPELAGO SEA (2)

VUOKSI (3) Pielisjärvi aubregion (a) 6.0 0 0 6.0 27 Xallaveai aubregion lb) 16 B.8 2.0 22 83 Saimaa (c) 15 0 0 13 48

KYMIJOKI (4) Keitele-Puijanne (a) 24 0 5.8 60 210 PHijanne (b) 23 0 7.5 41 150 Paljanne-Culf of Finland (c) 22 0 8.8 54 190

KOKEMÄENJOKI (S) Langelmaveai. Hauho and Vanaja watercouraea (a) 24 0 11 22 86 Khtari and Keuruu watercouraea. Paloveel-Pyhajarvl (b) 23 0 5.8 60 220 Pyhajarvl-Rautaveai. Ikaalinen watercourse. Kokemäenjoki and Loimijoki baaina (c) 22 0 13 39 140

RIVERS DISCHARGING INTO THE GULP OF BOTHNIA (6) 13 0 3.4 18 66

OULUJOKI (7) Hyrynsalmi watercourse (a) 9.0 0 0 3.7 17 Sotkamo watercourae (b) 23 0 0 34 130 Oulujarvl-Pohjanlahtl (c) 19 0 0 7.7 29

KIIMINCINJOKI. IIJOKI AND SIMOJOKI (8) 5.0

KEMIJOKI (9) 1.9

TORNIONJOKI (10)

RIVERS DISCHARCINC INTO THE ARCTIC OCEAN (11)

balow the detection limit

40 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Sr and giiai-ealtting radionuclides in the surface water of aoste drainage baaina and their subregions and in groups of riven diacharging into different aaa areas in May 1989 (Bq/ai ). The reaults are decay corrected to the aaapling date. The figures in bracketa refer to the nuaber of the drainage basin, and (a), (b) or (c) refer to the aubregion (cf. Fig. 2).

125. 13«-

RIVER3 DISCHARCINC INTO THE CULf Or riNLAND (1) 12

RIVERS DISCHARCINO INTO THE ARCHIPELAGO SEA (2) 31

VUOKSI (3) Pielisjärvi aubregion («) 10 0 10 50 Kallaveal aubregion (b) 14 0 11 55 Saimaa (c) 13 0 9.2 38

KYMIJOKI (4) Keltele-PSiJnnne (a) 20 4.3 36 160 Paijanne (b) 21 0 22 86 Paljanne-Culf of Finland (c) 18 0 33 140

KOKEMXENJOKI (5) Langelmttveal, Hauho and Vanaja watercouraea (a) 22 8.7 16 65 Khtari and Keuruu watercouraes, Palovesl-PyhaJHrvl (b) 20 0 40 160 Pyhajarvi-Rautavesi. Ikaalinen vatercourae, Kokemäenjoki and Loimijoki baaina (c) 20 5.2 21 90

RIVERS DISCHARCINC INTO THE CULT Of BOTHNIA (6) 11 0 13 58

OULUJOKI (7) Hyrynsalmi watercourse (a) 8.7 0 3.7 14 Sotkamo watercourse (b) 21 0 7.4 36 OuluJHrvi-PohJanlahti (c) 16 0 9.4 37

KIIMINCINJOKI. IIJOKI AND SIMOJOKI (8)

KEMIJOKI (9) 5.6 15

TORNIONJOKI (10) 6.2

RIVERS DISCHARCINC INTO THE ARCTIC OCEAN (11)

below the detection limit

41 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

Tabic VI Sr and gaui-eiitting radionuclide* In the surface water of some drainage baslna and their aubreglons and In groupe of rivers discharging Into different aea areaa In August 1989 (Bq/m ). The reaults are decay corrected to the sampling date. The figures In brackets refer to the number of the drainage baaln. and (a), (b) or (c) refer to the subreglon (cf. rig. 2).

134.

RIVERS DISCHARGING INTO THE CUL» O» »INLAND (1) 6.4

RIVERS DISCHARGING INTO THE ARCHIPELAGO SEA (2)

VUOKSI (3) Pielisjärvi subregion (a) 10 0 4. 1 20 Kallavesi subregion (b) 12 0 16 66 Saimaa (c) IS o 9. S 45 KYMIJOKI (4) Paijanne (b) 22 s.s 31 140 Paljunne-Gulf of »Inland (c) ie 4.e 35 170

KOKEMXENJOKI (5) Längelmävesi. Hauho and Vanaja watercourses (a) 20 7.2 15 62 XhtMri and Keuruu watercouraea, Palovesi-Pyhajarvl (b) 21 0 47 230 Pyhajarvi-Rautaveai, Ikaalinen watercourse, Kokemäenjoki and Loimijoki basins (c) ie S.6 26 130

RIVERS DISCHARGING INTO THE GULF O» BOTHNIA (6) ll 0 13 63

OULUJOKI (7) Hyrynsalmi watercourse (a) 10 O 3.5 16 Sotkamo watercourse (b) 20 O 22 110 Oulujärvi-Pohjanlahti (c) 17 O 5.7 33

KIIMINCINJOKI. IIJOKI AND SIMOJOKI (S) 2.2

KEMIJOKI (9)

TORNIONJOKI (10)

RIVERS DISCHARGING INTO THE ARCTIC OCEAN (11) 2.3

below the detection limit

42 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Table VII Sr and gaaaa-eaitting radianuclidaa in the lurfaci watar of IOIC drainage baaina and their eubragiona and in groupa of rivare diacharging into different aaa areae in October 19B9 (Bq/a ). The reaulta are decay corrected to the aaapling data The figurea in brackete refer to the nuaber of the drainage baain. and (a), (b) or (c) refer to the eubregion (cf. rig. 2).

125„

RIVERS DISCHARGING INTO THE OULF Of riNLAND (1) 4.1 52

b RIVER3 DISCKARCINC INTO THE ARCHIPELAGO SEA. (2)

VUOKSI (3) PlellejMrvl aubragion (a) 9. 7 O 3. 5 20 XallaTeai aubregion (b) 15 O 13 66 Saiaao (c) 12 O 9. 8 41

KYMIJOKI (4) Xeltele-PMljanne (a) 20 3.6 29 150 Paijanne (b) 27 O 22 120 Paljanne-Culf of rinland (c) 18 5.6 31 150

XOXEMXENJOKI (5) Langelaaveai. Hauho and Vanaja watarcouraea (a) 21 O 12 56 Ähtäri and Keuruu watercouraee. Palovael-Pyhajarvl (b) 24 6.0 39 180 PyhKjarvl-Rautaveal. Ikaalinen watercourae. XokeaHenjokl and Loimijoki baaina (c) 21 O 22 100

RIVERS DISCHARCINC INTO THE CULT Of BOTHNIA (6) 9. 3 1.8 10 55

OULUJOKI (7) Hyrynsalmi watercourse (a) 9.0 O 3.1 16 Sotkamo watercourse (b) 19 O 16 96 OulujHrvi-Pohjaniahti (c) 11 O 7.3 26

XIIMINCINJOXI. IIJOKI AND SIMOJOKI (8)

KEMIJOKI (9)

TORNIONJOKI (10)

RIVERS DISCHARGING INTO THE ARCTIC OCEAN (11)

not analyzed below the detection Unit

43 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

Table VIII sr and gamma-emitting radionuclides in tn* lurfici wittr of ion drainage baains and thalr aubreglons snd in groups of rlrtri diacharging into different aea areaa in May 1990 (Bq/a ). The reaulta are decay corrected to the aampling date. The figures in brsckete refer to the nuabcr of the drainage basin, and (a), (b) or (c) refer to the aubregion (cf. Fig. 2).

90_ 125. 137.

RIVERS DISCHARGING INTO THE GULr Or riNLAND (1)

RIVERS DISCHARGING INTO THE ARCHIPELAGO SEA (2)

VUOKSI (3) Pielisjärvi subreglon (a) 8. 3 O 2.4 15 Kallaveal aubregion (b) 14 O 7.9 50 Saimaa (c) 12 O 4.0 31

KYMIJOKI (4) Keitele-Paijanne (a) 16 o 20 110 Paijanne (b) 20 o 14 73 Paijanne-Culf of Finland (c) 14 o 19 110 KOKEMÄENJOKI (5) Längelmävesi. Hauho and Vanaja watarcouraea (a) 17 4. 6 9.5 52 Khtari and Keuruu watercourses. Peloveai-Pyhajarvi (b) 20 O 20 120 PyhHJarvl-Rautaveai. Ikaalinen watercourae. Kokemäenjoki and Loimijoki baalna (c) 15 o 16 89

RIVERS DISCHARGING INTO THE GULr Or BOTHNIA (6) 8.. 5 2. 1 6.8 39

OULUJOKI (7) Hyryn»aImi watercourse (a) 6.8 O 2.4 15 Sotkamo watercourae (b) 19 O 11 75 Oulujärvi-pohjanlahti (c) 9.9 O 6.4 22

KIIMINOINJOKI. IIJOKI AND SIMOJOKI (8)

KEMIJOKI (9)

TORNIONJOKI (10) 8.3

RIVERS DISCHARGING INTO THE ARCTIC OCEAK (11)

below tha detection limit

44 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Table ZX Sr and gamma-ealttlng radlonuelldaa in the lurfaci water of aoma drainage baslna and thalr aubraglona and In groupa of rlvara dlacharglng Into different sea areas in October 1990 (Bq/m ). The resulta are decay corrected to the sampling data The figures in bracketa refer to the number of the drainag» basin, and (a), (b) or (c) refer to the aubregion (cf. Pig. 2).

RIVERS DISCHARCINC INTO THE CULr Or FINLAND (1)

RIVERS DISCHARGING INTO THE ARCHIPELAGO SEA (2)

VUOKSI (3) PialiajMrvi subragion (a) 9.5 O 2.0 15 Kallaveai subregion (b) 13 0 7.2 51 Saimaa (c) 12 o 4.3 30

KYMIJOKI 14) Keitele-Paijanne (a) 20 3.2 19 120 Paljunne (b) 20 O 11 79 Paijanne-Culf of Finland (c) 11 2.9 12 81

KOKEMKENJOXI (5) LangelnHveal, Hhuho and Vanaja watercouraea (a) XhtMri and Keuruu watorcouraea. Paloveel-Pyhajarvl (b) 20 PyhajMrvl-Rautavesi. Ikaalinen watercourse. Kokemäenjoki and Loimijoki basins (c)

RIVERS DISCHARGING INTO THE GULP Or BOTHNIA (6)

OULUJOKI (7) Hyrynsalmi watercourse (a) 6.5 O 9.0 Sotkamo watercourse (b) 15 9.0 68 OuluJHrwi-Pohjanlahtl (c) 12 5.5 19

KIIHINGINJOKI. IIJOKI ANC SIMOJOKI (8) 6.7 7.6

KEMIJOKI (9)

TORNIONJOKI (10)

RIVERS DISCHARGING INTO THE ARCTIC OCEAN (11)

below the detection limit

45 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

Table X. "Sr and gamma-emitting radionuclides in the surface water (in Bq m"3) in the mouths of Finland's five largest rivers discharging into the Baltic Sea in 1988.

Sampling month/river "Sr 12SSb 134Cs 137Cs

March Kymijoki 27 16 87 250 Kokemäenjoki 31 20 70 210 Oulujoki 24 0a 6.4 21 Kemijoki 7.5 2.5 5.3 17 Tornionjoki 6.4 0 2.6 7.7

May Kymijoki 24 9.1 65 200 Kokemäenjoki 24 13 62 190 Oulujoki 13 0 6.3 24 Kemijoki 6.8 1.6 3.7 17 Tornionjoki 5.7 1.4 2.9 13

August Kymijoki 26 12 74 250 Kokemäenjoki 27 14 46 160 Oulujoki 16 0 6.6 32 Kemijoki 6.7 0 1.9 10 Tornionjoki 6.7 0 1.7 6.7

October Kymijoki 23 10 60 220 Kokemäenjoki 25 11 44 160 Oulujoki 15 0 5.6 23 Kemijoki 6.7 0 0 3.3 Tornionjoki 6.7 0 1.2 4.3

below the detection limit

46 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Table XI. «'Sr and gamma-emitting radionuclides in the surface water (in Bq m"3) in the mouths of Finland's five largest rivers discharging into the Baltic Sea in 1989.

Sampling month/river "Sr 12SSb 134Cs 137Cs

March Kymijoki 22 8.7 36 150 Kokemäenjoki 23 6.1 28 120 Oulujoki 18 0.75 4.3 22 Kemijoki 6.6 1.4 1.2 5.7 Tornionjoki 7.2 0a 1.2 6.4

May Kymijoki 25 8.7 47 200 Kokemäenjoki 18 7.2 23 100 Oulujoki 13 0.92 4.0 21 Kemijoki 4.6 0 1.3 7.5 Tornionjoki 5.2 0 1.6 7.4

August Kymijoki 27 6.8 49 220 Kokemäenjoki 25 6.2 21 93 Oulujoki 15 0 4.4 26 Kemijoki 7.4 0 0 4.9 Tornionjoki 6.9 0 3.1 13

October Kymijoki 22 6.4 31 160 Kokemäenjoki 20 5.3 16 76 Oulujoki 13 0 3.2 19 Kemijoki 6.6 0 0 4.0 Tornionjoki 6.3 0 1.3 6.0

below the detection limit

47 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

Table XII. "Sr and gamma-emitting radionuclides in the surface water (in Bq m"3) in the mouths of Finland's five largest rivers discharging into the Baltic Sea in 1990.

Sampling month/river "Sr 12SSb 134Cs 137Cs

March Kymijoki 23 0a 15 83 Kokemäenjoki 23 5.3 20 110 Oulujoki 14 0 2.5 11 Kemijoki 6.9 0 0 5.7 Tornionjoki 6.2 0 0 4.5

May Kymijoki 22 3.9 13 74 Kokemäenjoki 22 0 13 73 Oulujoki 11 0 2.0 13 Kemijoki 5.3 0 1.3 9.0 Tornionjoki 4.7 0 0.65 5.7

August Kymijoki 25 5.1 26 160 Kokemäenjoki 22 5.3 11 63 Oulujoki 12 0 2.4 17 Kemijoki 7.1 0 0 6.0 Tornionjoki 6.9 0 1.5 12

October Kymijoki 23 4.9 19 130 Kokemäenjoki 20 0 13 88 Oulujoki 13 0 2.0 16 Kemijoki 6.3 0 0 4.8 Tornionjoki 5.1 0 0 4.1

" below the detection limit

48 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Table XIII. ^Sr and gamma-emitting radionuclides in the surface water (in Bq m"3) in three rivers discharging into the Gulf of Finland in 1990.

River Sampling ^Sr 12SSb 134 Cs 137Cs date

Porvoonjoki 8.3. 10 0* 3.9 23 Vantaanjoki 8.3. 9.8 0 2.7 16 Karjaanjoki 14.3. 9.4 0 1.3 6.6

Porvoonjoki 11.5. 20 0 2.1 14 Vantaanjoki 14.5. 23 0 1.7 8.7 Karjaanjoki 14.5. 5.6 0 1.4 5.6

Porvoonjoki 7.8. 13 0 1.8 10 Vantaanjoki 7.8. 7.8 0 1.6 9.5 Karjaanjoki 10.8. _b 0 0 4.7

Porvoonjoki 11.10. 13 2.7 7.8 50 Vantaanjoki 24.10. 11 0 3.3 22 Karjaanjoki 11.10. 9.7 0 0 4.9

* below the detection limit b not analysed

49 Table XIV. Activity concentrations of 3H in surface water samples in 1988 and 1989 (kBq/m3). For sampling stations see Fig. 1. 2 S£

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

River

Kemijoki 1988 6.1 4.3 5.0 4.1 5.0 3.6 4.8 4.2 4.0 3.7 3.6 5.0 1989 5.4 4.5 4.9 4.9 2.9 4.0 4.0 4.4 4.3 3.6 3.7 4.0 o 25 Lake.

Päijänne 1988 3.8 3.6 5.2 3.0 4.3 3.1 4.8 3.8 4.2 4.2 3.1 5.0 1989 3.5 3.8 4.2 4.7 4.2 4.1 5.1 4.3 2.7 3.3 3.3 3.6

Inari 1988 3.8 4.2 4.1 3.3 3.6 3.6 4.5 4.7 4.0 3.8 3.8 4.3 1989 3.7 4.3 4.5 5.1 5.2 5.1 4.3 3.0 3.7 4.4 4.2 4.0

(A

K £ •**• Tabic XV. The average activity concentrationa (i) and the variation in Ce and C« (Bq/kg freeh weight) in varioua fiah apeciaa in the largeat lakea (aurface area > 890 km . claaa 1) in Finland in 1988. The number of aaaplea ia alao given (n).

FISH Ca Ca SPECIES Bin sin

HXHE .

PXUXHNE BURBOT 1 810 810 810 3200 3200 3200 PERCH 2 1100 610 1600 3700 2100 5300 PIKE 3 1400 930 2100 4900 3600 7000 PIKE-PERCH 1 390 390 390 1300 1300 1300 VENDACE 2 110 90 140 4 60 360 550 UHITEFISH 3 260 120 490 900 460 1500

CENTRAL FINLAND

PXljXNHE BREAM 3 270 140 500 930 540 1600 BURBOT 4 670 300 1400 2300 1100 4700 PERCH 3 430 350 530 1600 1300 2000 PIKE 4 670 300 1300 2300 1100 4100 PIKE-PERCH 2 1100 480 1700 3800 1800 5800 ROACH 4 170 87 250 650 360 910 TROUT 1 2 50 250 250 930 930 930 VENDACE 1 150 150 150 530 530 530 UHITEFISH 5 170 S3 380 G40 350 1400

KUOPIO

KALLAVESI BURBOT 2 200 150 240 740 500 980 PERCH 5 100 33 140 380 120 530 PIKE 2 120 78 170 430 310 540 VENDACE 1 14 14 14 57 57 57 UHITEFISH 2 50 30 70 200 120 270

KYHI

SAIMAA BREAM 1 38 38 38 150 150 150 PERCH 4 140 75 210 520 280 770 PIKE 3 140 79 190 530 330 720 PIKE-PERCH 1 160 160 160 570 570 570 ROACH 3 64 46 84 250 180 310 UHITEFISH 3 39 30 45 140 110 170

MIKKELI

SAIMAA BREAM 2 13 12 14 45 44 45 PERCH 6 59 15 160 200 61 550 PIKE 2 120 21 210 420 85 760 ROACH 2 9.2 6.4 12 39 30 47 UHITEFISH 1 62 62 62 240 240 240

OULU

OULUJXRVI BREAM 2 16 10 22 74 44 100 BURBOT 1 57 57 57 260 260 260 DACE 1 23 23 23 100 100 100 PERCH 2 64 61 67 280 260 310 PIKE 2 43 30 56 210 140 270 ROACH 1 3.8 3.8 3.8 19 19 19 TROUT 1 62 62 62 250 250 250 VENDACE 2 27 27 27 88 58 120 UHITEFISH 2 29 15 42 120 62 160

51 Table XVI. The average activity concentrations (x) and the variation in Cs and _ Ca (Bq/kg fresh weight) in various fish species in lakea with a aurface area of sore than 20 km (class 2) in 1988. The area of most of the lakes in thla class exceeds 100 km . The number of samples is «lao given (n).

PROVINCE* FISH 134c. 137c. LAKE SPECIES n X min aax X • In • ax

HXME

KUOHIJXRVI BURBOT 1300 1300 1300 4700 4700 4700 PERCH 1900 1900 1900 6600 6600 6600 PIKE-PERCH 1600 1600 1600 5500 5500 5500 ROACH 210 210 210 820 820 820 TROUT S90 890 890 3000 3000 3000 UHITEFISH 510 510 510 1700 1700 1700 NXSIJXRVI BREAM 230 120 340 830 450 1200 BURBOT 1200 1000 1400 4300 3900 4800 PIKE 1400 1000 1700 4700 3700 5800 SMELT 510 510 510 1700 1700 1700 UHITEFISH 250 250 250 1000 1000 1000 PXLKXNEVESI BREAM 46 46 46 170 170 170 BURBOT ilO 310 310 1100 1100 1100 PERCH 95 64 130 350 260 460 PIKE 310 310 310 1000 1000 1000 ROACH 2 39 32 45 140 120 150 PYHXJXRVI BREAM 1 16 16 16 68 68 68 (PIRKKALA) BURBOT 2 130 110 150 490 480 500 PERCH 6 160 37 300 580 160 1000 PIKE 2 140 BB 200 510 310 720 PIKE-PERCH 3 130 B6 180 460 330 650 ROACH 1 63 63 63 22C 220 220 SILVER BREAM 1 21 21 21 95 95 95 UHITEFISH 1 62 62 62 240 240 240 PYHXJXRVI BREAM 2 11 10 12 33 32 33 (TAMMELA) BURBOT 2 37 27 47 150 110 200 PERCH 4 37 18 65 140 62 250 PIKE 2 47 40 54 1B0 150 210 PIKE-PERCH I 41 41 41 150 150 150 ROACH 2 9.2 8.4 10 40 37 43 TARJANNEVESI IDE I 100 100 100 400 400 400 PERCH 2 380 290 470 1500 1200 1B00 PIKE 1 400 400 400 1500 1500 1500 VESIJXRVI BREAM 1 200 200 200 650 650 650 BURBOT 2 300 2B0 320 1100 1100 1200 PERCH 5 260 140 460 1000 510 1800 PIKE 3 210 170 250 800 610 930 PIKE-PERCH 3 200 160 260 750 690 870 ROACH 1 55 55 55 200 200 200 UHITEFISH 2 51 32 69 210 160 260

CENTRAL FINLAND

KEITELE BURBOT 720 600 B20 2800 2400 3300 PERCH 420 150 660 1500 620 2300 PIKE 690 390 1100 2600 1500 3900 ROACH 170 120 240 700 490 900 VENDACE 100 99 100 400 390 410 UHITEFISH 180 180 leo 650 650 650 KEURUSSELKX BREAM 200 170 230 740 740 750 BURBOT 570 570 570 2200 2200 2200 PERCH 460 300 730 1B00 1100 2800 PIKE 600 510 650 2200 1700 2400 VENDACE 110 110 110 410 410 410 KIVIJÄRVI PERCH 780 420 1200 2600 1600 4000 PIKE 1500 1E00 1500 5100 5000 5100 ROACH 420 400 440 1500 1400 1500 MUURATJXRVI BREAM 39 39 39 160 160 160 BURBOT 180 1B0 1B0 720 720 720 IDE 53 53 53 210 210 210 PERCH 170 150 190 600 530 640 PIKE 190 190 190 720 720 720 ROACH 56 51 61 210 200 210 UHITEFISH 60 60 60 240 240 240 SUONTEE BREAM 100 99 110 370 350 390 IDE 34 34 34 130 130 130 PERCH 350 260 430 1200 940 1500 PIKE 370 370 370 1500 1500 1500 ROACH 91 91 91 310 310 310 RUDD 69 69 69 260 260 260

52 Tabic XVI continued

PROVINCE riSH 134C« 137C» LAKE SPECIES n X sin >u x Bin sax

KUOPIO

KONNEVESI BREAH 4 210 110 370 750 410 1300 BURBOT 3 640 530 830 2300 2000 260.3 PERCH 4 480 220 650 1700 790 2500 PIKE 3 560 440 770 2000 1700 2500 ROACH 2 150 110 190 550 440 660 TROUT 1 600 600 600 2200 2200 2200 UHITEFISH 3 140 110 190 560 450 680 NILAKKA BURBOT 2 520 500 540 1900 1800 2100 PERCH 4 230 120 430 850 470 1500 PIKE 1 560 560 560 1900 1900 1900 ROACH 3 110 74 160 400 300 570 UHITEFISH 1 140 140 140 520 520 520 ONKIVESI BREAM 1 8.9 8.9 8.9 28 28 28 BURBOT 1 36 36 36 140 140 140 PERCH 1 48 48 48 170 170 170 PIKE 1 60 60 GO 200 200 200 PIKE-PERCH 1 33 33 33 120 120 120 ROACH 1 17 17 17 64 64 64 SORSAVESI BREAM 1 680 680 680 2300 2300 2300 PERCH 2 1000 710 1300 3400 2600 4100 PIKE 2 1200 1100 1200 4100 4000 4100 ROACH 2 290 230 360 1000 850 1200 VENDACE 1 360 360 360 1400 1400 1400 SUONTIENSELKA VENDACE 1 170 170 170 590 590 590

KYMI

VUOHIJXRVI BURBOT 2 400 310 500 1400 1100 1700 PERCH 6 530 270 1200 1800 1000 4000 PIKE 1 530 530 530 1900 1900 1900 ROACH 2 140 130 160 510 480 540

MIKKELI

HAUKIVESI BREAM 1 48 48 48 190 190 190 BURBOT 1 260 260 260 1000 1000 1000 PERCH 1 150 ISO 150 590 590 590 PIKE 1 270 270 270 1000 1000 1000 PIKE-PERCH 1 250 250 250 970 970 970 VENDACE 1 38 38 38 150 150 150 KORPUXRVI PERCH 2 170 130 210 620 470 760 PIKE 1 290 290 290 1000 1000 1000 UHITEFISH 2 86 83 88 310 310 320 KYYVESI BREAM 1 160 160 160 600 600 600 BURBOT 1 370 370 370 1600 1600 1600 IDE 1 300 300 300 1000 1000 1000 PIKE 1 560 560 560 1800 1800 1800 ROACH 3 140 90 230 510 380 760 VENDACE 1 60 60 60 230 230 230 PURUVESI BURBOT 1 220 220 220 890 890 890 PERCH 4 290 230 370 1100 820 1300 PIKE 2 410 200 620 1400 810 2100 ROACH 2 170 130 210 620 480 760 VENDACE 1 84 84 84 330 330 330 UHITEFISH 3 73 58 100 270 220 360 PUULA BREAM 2 83 42 120 310 200 430 BURBOT 2 140 99 170 510 430 580 PERCH 6 160 82 210 630 370 810 PIKE 4 190 150 240 720 620 810 ROACH 2 66 59 72 260 260 260 SMELT 3 67 58 81 260 230 300 VENDACE 2 76 64 88 270 240 300 UHITEFISH 3 38 11 53 170 44 260

OULU

LENTUA BURBOT 3 400 360 450 1700 1600 1800 PERCH 4 530 280 640 2100 1200 2600 PIKE 3 360 250 540 1500 1200 2200 ROACH 2 140 130 150 540 530 550 VENDACE 1 79 79 79 340 340 340 UHITEFISH 3 140 82 230 580 370 960

53 TaDie XVJ. continued

PROVINCE nsH 134c. 137c. LAKE SPECIES n X min BII X • In • ax

NORTH KARELIA

ORIVESI BREAK 1 13 13 13 57 57 57 BURBOT 1 45 45 45 160 160 160 PERCH 2 36 25 46 170 140 200 PIKE 2 32 16 47 140 87 190 PIKE-PERCH 2 34 26 42 150 130 170 ROACH 1 6.2 6.2 6.2 35 35 35 VENDACE 1 S.2 5.2 5.2 29 29 29 UHITEPISH 2 29 7.5 51 110 32 180

TURKU AND PORI

KYROSJXRVI BREAK 6 SO 52 150 300 210 460 BURBOT 6 590 520 730 2100 1800 2300 IDE 2 110 100 110 340 330 350 PERCH 11 350 S4 1000 1200 310 3500 PIKE 19 540 110 SOO 1900 390 2500 PIKE-PERCH 1 660 660 660 2500 2500 2500 VENDACE U 74 43 110 2S0 170 380 WHITE BREAM 1 120 120 120 4 20 420 420 PYHXJXRVI PERCH 1 100 100 100 440 440 440 PIKE 1 93 93 93 350 350 350 ROACH 1 38 38 38 150 150 150 VENDACE 2 36 20 52 130 93 160 SXKKSJKRVI PERCH 4 210 66 320 750 240 1100 PIKE 2 160 140 ISO 550 490 610 ROACH 2 60 4S 72 220 180 250 VENDACE 2 38 29 46 140 110 160

VAASA

LESTIJÄRVI BURBOT 1 91 91 91 360 360 360 PERCH 3 540 390 630 2000 1500 2400 PIKE 2 3S0 190 5B0 1300 780 1900 ROACH 1 130 130 130 500 500 500 VENDACE 2 110 100 130 4B0 450 500 UHITEFISH 1 130 130 130 490 490 490 XHTXRINJXRVI PERCH B 4S0 24 930 1700 96 3200 PIKE 4 460 320 5B0 1700 1400 2000 UHITEFISH 4 220 130 340 780 S40 1200 Table XVII. The average activity concentrations Ix) and the variation in Ca and Ca (Bq/kg fresh weisht) in various fiah apeclea in lakes with a aurface area smaller than 20 km but larger than 1 km (claas 3) in 1966. The number of samples is also given (n).

PROVINCE FISH Cs Cs LAKE SPECIES sin sin

HXHE

ALINEN ALUXRVI PERCH 1300 1200 1600 4800 4300 5400 PIKE 620 620 620 2400 2400 2400 EKOJXRVI PIKE 720 580 850 2400 1900 2900 HAAPAJÄRVI PIKE 110 110 110 380 380 380 KATUMAJXRVI BREAM 42 26 57 150 110 190 PERCH 220 100 400 680 270 1400 PIKE 260 110 410 910 410 1400 ROACH 71 45 97 250 170 330 VENDACE 82 56 110 280 200 350 UHITEFISH 60 60 60 240 240 240 KEIHXSJXRVI BURBOT 1000 1000 1000 3 200 3200 3200 PERCH 530 510 550 1900 1900 1900 PIKE 1200 1000 1400 4 200 3600 4800 ROACH 440 440 440 1500 1500 1500 VENDACE 130 130 130 470 470 470 KERTEJXRVI BREAM 290 290 290 960 9 60 960 BURBOT 930 620 1200 3200 2300 4200 PERCH 520 370 620 1S00 1400 2100 PIKE 1100 790 1400 3800 2900 4600 ROACH 230 170 280 750 610 900 VENDACE 190 190 190 720 720 720 NYLLYJXRVI BURBOT 3000 3000 3000 11000 11000 11000 PERCH 2 600 2000 3100 9300 7500 11000 PIKE 2 600 2600 2600 9000 9000 9000 ROACH 890 890 890 3300 3300 3300 PXXJXRVI PERCH 130 99 170 540 400 680 PIKE 200 200 200 730 730 730 PIKE-PERCH 110 110 110 460 4 60 460 ROACH 44 44 44 170 170 170 TROUT 75 75 75 280 280 2S0 VENDACE 62 62 62 250 250 250 VEHKAJXRVI BURBOT 4600 4600 4600 15000 15000 15000 PERCH 6300 6300 6300 20000 20000 20000 PIKE 4300 4300 4300 14000 14000 14000 ROACH 1300 1300 1300 4400 4400 4400

CENTRAL FINLAND

BREAM 2 77 62 91 280 260 300 PERCH 4 370 190 740 1300 630 2600 PIKE 2 290 210 360 1000 800 1300 PETXJXVESI BREAM 2 64 48 SO 230 190 270 PERCH 4 140 7B 210 510 320 760 PIKE 2 300 100 490 1000 400 1600 ROACH 2 69 51 87 250 200 290 VALKEAJXRVI BREAM 1 340 340 340 1300 1300 1300 PERCH 5 1B00 1300 2900 6300 4B00 9B00 PIKE 2 2600 2300 2900 B600 7700 9600 ROACH 2 560 410 720 2000 1500 2500

ISO-II BREAM 1 14 14 14 49 49 49 PERCH 1 24 24 24 87 87 87 PIKE 1 32 32 32 110 110 110 PIKE-PERCH 1 20 20 20 95 95 95

KVHI

JUNKKARINJXIWI BREAM 2 120 38 210 390 140 650 PERCH 5 140 34 400 470 130 1300 PIKE 2 74 56 92 260 220 310

MIKKELI

PIEKSXNJXRVI PERCH 3 2900 1S00 3500 9800 5900 12000 PIKE 2 1S00 1000 2600 6000 3900 8100 ROACH 1 S10 rio S10 2600 2600 2600 VENDACE 1 590 590 590 1900 1900 1900

55 Table XVII continued

PROVINCE FISH 134c. Ca LUKE SPECIES n z Bin • ax x~ • in »ax

PYHXJXRVI BREAM 1 830 830 830 2800 2B00 2B00 PERCH 2 1600 1600 1700 5500 5200 5900 PIKE 2 1800 1400 2300 6200 5100 7200 ROACH 2 840 6B0 990 3000 2500 3400 VENDACE I 490 490 490 1800 1800 1B00 RUOKOJXRVI BREAK 1 69 69 69 220 220 220 PERCH 2 80 7B 82 330 330 340 ROACH 1 SB SB 58 220 220 220 VENOACE 1 72 72 72 2B0 2B0 280 VANAJAJXRVI BURBOT 1 1100 1100 1100 4000 4000 4000 PERCH 3 1200 BIO 1900 4300 3000 6000 PIKE 2 1900 1500 2200 6200 5300 7100 ROACH 1 440 440 440 1600 1600 1600 VENDACE 1 B90 890 B90 3400 3400 3400

OULU

HYRYNJXRVI BURBOT 1 42 42 42 180 180 ISO PERCH 3 39 33 SO 180 160 230 PIKE 2 26 20 31 130 110 140 ROACH 2 6.4 6.4 6.4 33 29 37 VENDACE 3 9.8 7.5 12 39 23 57 UHITEFISH 2 10 6.7 14 SO 37 63

TURKU AND PORI

HOUHAJXRVI BREAM 2 66 S3 7B 240 1B0 310 PERCH 1 210 210 210 300 300 300 PIKE 2 180 160 200 64 0 630 650 ROACH 1 50 SO SO 200 200 200 JXMIJXRVI BREAM 2 37 35 38 120 9B 130 BURBOT 1 80 80 BO 280 2B0 280 PERCH 2 120 120 120 440 420 450 PIKE 2 160 130 1B0 590 500 69 0 PIKE-PERCH 2 330 220 430 1100 B90 1400 KARVIANJXRVI PERCH 2 140 110 170 530 440 620 PIKE 240 240 240 860 860 860 ROACH 75 75 75 270 270 27 0 KIRKKOJXRVI BREAM o" 0 0 3.1 3.1 3 PERCH 7.9 7.9 7.9 33 33 33 PIKE 6.3 6.3 6.3 24 24 24 PIKE-PERCH 6.7 6.7 6.7 27 27 27 KÖYHÖNJXRVI BREAM 6.7 6.7 6.7 31 31 31 PERCH 19 16 21 73 54 91 PIKE 21 21 21 76 76 76 PIKE-PERCH 29 29 29 110 110 110 ROACH 5.1 5.1 S.l 17 17 17 VAHOJKRVI BURBOT 1000 800 1200 3S00 2600 4500 PERCH 670 540 820 2300 2100 2700 PIKE BIO 810 BIO 2900 2900 2900 ROACH 2 220 190 250 780 640 920

ENXJXRVI PERCH 1 49 49 49 200 200 200 PIKE 1 29 29 29 130 130 130 ROACH 1 0 0 0 26 26 26 KYTÄJKRVI BREAM 3 3.8 2.9 4.8 14 13 IS PERCH 6 15 5.4 2B 56 IB 110 PIKE 2 11 B.l 13 37 33 40 PIKE-PERCH 2 IB 17 19 69 64 74 ROACH 3 7 4.3 B.6 26 IB 31

VAASA

KUORTANEENJXRVI BREAM 1 38 38 38 130 130 130 PERCH 2 80 52 110 290 190 390 PIKE 1 64 64 64 240 240 240 ULLAVANJXRVI BREAM 2 89 70 110 310 270 360 PERCH 3 210 150 260 730 540 BSO PIKE 2 370 310 420 1300 1200 1400

below the detection limit

56 Table XVIII. The average activity concentration» (x) and the variation by province in Ci and Ca (Bq/kg fresh weight) in varloua fiah apeclea in lakea with a turfice area of leas than 1 km (clan 4) in 1988. The number of • atopies la alao given (n).

137 FISH Ca Ca SPECIES nln min

PERCH 48 2000 360 5400 7200 1500 18000 PIKE 37 2800 600 7900 9200 1700 26000 PIKE-PERCH 1 1500 1500 1500 5600 5600 5600 ROACH 16 710 200 2100 2500 800 7000 RUFF 1 960 960 960 3400 3400 3400 UHITEFISH 14 1300 610 2800 4500 2200 9500

CENTRAL FINLAND

BREAM 1 66 66 66 250 250 250 PERCH 2 270 210 320 940 730 1200 PIKE 1 530 530 530 1900 1900 1900

BREAM 2 96 73 120 360 280 440 BURBOT 1 240 240 240 840 840 84 0 PERCH 6 500 110 1300 1800 480 4600 PIKE 4 930 260 1700 3300 980 5700 ROACH 3 450 80 740 1500 310 2400 UHITEFISH 2 480 370 590 1600 1300 1900

MIKKELI

PERCH 4 420 190 570 1600 680 2100 PIKE 3 800 520 1000 2700 1800 3500 ROACH 1 190 190 190 760 760 760

PERCH 16 590 500 700 920 41 2600 PIKE 10 1000 990 1100 1700 100 4200 ROACH 7 280 260 290 480 26 1200

TURKU AND PORI

PERCH 2 630 430 830 2200 1600 2700 PIKE 2 570 510 640 2000 1900 2100 ROACH 2 110 86 130 380 330 440

UUSIMAA

BREAM 1 o' 0 0 6.8 6.8 6. PERCH 6 77 48 110 280 190 390 PIKE 3 71 9.3 130 260 40 440 ROACH 3 27 27 28 100 100 100

VAASA

PERCH 3 220 160 260 760 580 930 PIKE 2 310 230 390 1000 820 1300 ROACH 2 93 61 130 320 230 400

below the detection limit

57 137. T«ble XIX- The average activity concentration* (ij and the variation in 13«*""c, « and *-'ca (Bq/kg freah walght) in varioua fiah apeciea in the largeat lakea (eurface area > 890 km . claaa I) in 'inland in 1989. The number of aamplea ia alao given (n).

137 PROVINCE 134, FISH Ca Ca LAKE SPECIES n X min maa X min • ax

HXHE

PXIJXNNE UHITEFISH 1 170 170 170 710 710 710

CENTRAL riNLAND

PXIJXNNE BREAM 5 63 26 170 290 150 730 BURBOT 5 210 1B0 320 1000 810 1600 IDE 1 41 41 41 210 210 210 PERCH 10 250 S3 590 1200 420 2600 PIKE 4 300 230 370 1400 950 1900 ROACH 6 79 52 140 370 260 620 VHITEFISH 3 73 47 100 340 240 440

KUOPIO

KALLAVESI BURBOT 2 58 28 87 270 160 390 PERCH 4 44 37 50 220 170 270 PIKE 1 73 73 73 330 330 330 PIKE-PERCH 1 17 17 17 93 93 93 VENDACE 1 6.1 6.1 6.1 33 33 33 UHITEFISH 1 25 2S 25 110 110 110

KYHI

SAIMAA PERCH 3 99 44 150 520 260 690 PIKE 2 30 13 46 440 280 610 ROACH 2 34 29 38 180 170 200 VHITEFISH 3 23 13 38 120 71 170

BREAM 2 11 9 13 54 48 60 PERCH 5 11 8.5 14 62 49 75 PIKE 2 15 11 19 72 54 90 PIKE-PERCH 1 19 19 19 100 100 100 ROACH 1 6.4 6.4 6.4 31 31 31

OULU

OULUJÄRVI BREAM 1 19 19 19 100 100 100 DACE 1 23 23 23 130 130 130 PERCH 1 69 69 69 400 4 00 400 PIKE I 55 55 55 290 290 290 ROACH 1 14 14 14 75 75 75 SMELT 1 18 18 18 94 94 94 TROUT 1 42 42 42 250 250 250 UHITEFISH 1 26 26 26 130 130 130

58 The average activity concentration» (a) and the variation in Ca and Ca (Bq/kg freah weight) In varloua flah apeclea In lakes with a surface area of »ore than 20 km (clan 2) In 19B9. The area of stoat of the lakea In thla claaa exceed» 100 kat The number of samples la alao given (n).

PROVINCE FISH CB CB LAKE SPECIES n X nln • ax X mln • ax

HAME

KUOHUXRVI BURBOT 1 530 530 530 3000 3000 3000 PERCH l 860 860 860 4400 4400 4400 PIKE 2 660 600 710 3500 3200 3700 PIKE-PERCH 2 650 600 700 3300 3000 3600 ROACH 1 160 160 160 840 840 840 VENDACE 1 - 130 130 130 710 710 710 UHITEFISH 1 180 180 180 850 850 850 NXSUXRVI BURBOT 1 520 520 520 2400 2400 2400 PIKE 1 1100 1100 1100 4800 4800 4800 TROUT 1 1200 1200 1200 2100 2100 2100 UHITEFISH 1 420 420 420 1900 1900 1900 PXLXXNEVESI BREAM 1 23 23 23 98 98 98 PIKE 2 93 87 99 440 420 450 ROACH 2 25 17 32 120 92 150 VENDACE 1 55 55 55 240 240 240 PYHÄJXRVI BREAM 2 24 18 29 110 88 130 (PIRKKALA) BURBOT 1 61 61 61 280 280 280 PERCH 4 72 70 73 350 330 350 PIKE 2 94 84 100 490 410 570 PIKE-PERCH 2 56 40 71 250 190 310 ROACH 1 40 40 40 190 190 190 SILVER BREAM 2 29 15 42 140 84 210 SMELT 1 11 11 11 53 53 53 PYHÄJÄRVI BREAM 1 5 5 5 25 25 25 (TAMMELA) BURBOT 2 23 18 27 110 92 120 PERCH 2 29 27 31 150 130 180 PIKE 2 68 19 120 150 97 200 PIKE-PERCH 1 18 IB 18 94 94 94 ROACH 2 5.7 4.6 6.8 28 25 30 VENDACE 1 4.9 4.9 4.9 27 27 27 TOISVESI PERCH 1 77 77 77 410 410 410 PIKE I 99 99 99 460 4 60 460 ROACH 1 38 38 38 190 190 190 UHITEFISH 1 59 59 59 290 290 290 VESIJAKO PIKE 1 2400 2400 2400 9900 9900 9900 VESIJÄRVI BREAM 2 29 19 39 140 100 170 BURBOT 2 130 85 180 500 460 540 PERCH 2 250 120 380 1200 630 1700 PIKE 2 200 110 290 BOO 540 1100 PIKE-PERCH 2 140 110 170 630 540 720 UHITEFISH 2 32 30 34 150 150 160

CENTRAL FINLAND

KEITELE BREAM 1 190 190 190 870 870 870 BURBOT 1 580 580 580 2600 2600 2600 PERCH 4 350 96 550 1600 480 2500 PIKE 2 580 450 710 2500 2100 3000 ROACH 2 190 160 220 890 BOO 990 UHITEFISH 1 150 150 150 740 740 740 KEURUSSELKÄ BREAM 1 82 82 82 370 370 370 BURBOT 1 300 300 300 1400 1400 1400 PIKE 2 360 250 480 1600 1300 1900 VENDACE 1 39 39 39 210 210 210 KIVIJÄRVI BURBOT 1 630 630 630 3100 3100 3100 PERCH 5 430 340 550 2100 1700 2400 PIKE 3 530 400 630 2 600 2100 3000 PIKE-PERCH 1 420 420 420 2100 2100 2100 ROACH 1 170 170 170 890 890 890 UHITEFISH 1 240 240 240 1000 1000 1000 MUURATJXRVI BREAM 1 25 25 25 120 120 120 BURBOT 1 180 180 180 800 800 800 PERCH 2 88 84 91 400 4 00 4 00 PIKE 2 98 69 130 4 60 360 570 PXÄJXRVI BREAM 2 59 54 63 280 250 300 IDE 1 59 59 59 280 280 280 PERCH 2 230 200 250 1200 1000 1400 PIKE 2 150 140 160 770 720 820 PIKE-PERCH 1 170 170 170 860 860 860 UHITEFISH 2 110 69 150 590 340 850

59 o a

, , , , , , C so -o *o C < M » 13 "O C<50 0 aMCBCB< 0 OCB< 0 0'OMCBCB *Ö C M TJ TJ BJ »•OB w •< x o M n xnaOMtnxpiOMpiocajMMMCpiMMinocaj n x o M n c xOMMxOMpicOMmcso oma M > S* SO 50 M > Ä » SO >>n M 10 HOMO HafOPiOHOono ca>oPiocaopiPio w > O H O M O BJ HOMOHOPIOtDOnOa)> m > -f x X n > I x 02> x O > i x O 3 X M X X O n i xnx xox x o 3 "2 > •no *n o HO HO*O H " = MM M m m u u o

KI M M KI U U

M u u u U KI U U N O OI KI M U *• KI -J M *o H si si n O U< ID » U 0< MOUIU09«0^0>0>*0OiO>MLJ M O O O O tO 09 'O O O O OOOOKIOOOOKIOOOO

M U U U KI M M M MMM M M U KI KI U M *J KI KIMU *. KI -J M « M *J M 00 00 U« 03 KI M UI MlO*OiO)iO*0>OilOO>OH U i. 2 *J 09 *0 O O O M O O O O *o *o -j *• *JQM*JUIOOOOO>*-OOO*JOKIUIUOO OOOOKIOOOO

M U *> U MM N N M H MMM MMM M UN» U M *0 K) KIMU *> U -J M UIUKI*>KIMUlU«00)*>UltO*JUa)*>KIMOtUIMMOtU O Ui D> oi «J sj MMOtU09tO*OtOt*OOiMM U «o M *j u a t0<0*JKIOQO*J*>OOOO0>*>OOO*JOOOUOO C3 09 « O O O OOOOKIOOOOKIOOOO KI o o o o

M UU M M KIMU *. ui o* *o %o KJHHHU1UIKIH*UQ)«JOIUH«OIOI *J *. *• DM * KI *. «O 09 O U *> O sl » »H N KI 0> KI 09 M -J ~J O O O 'JUIUIOIAOHVlOOkNUlU'JHUHlOaAA'JOOl Ui -J M O O O OUIOOUIKlOOO*JOOOKI -JM*. o o o o o OOOOOOOOOOOOOOOOOOUIOOOKIOO O O O O O O oooooooooooooo o o o

AUlOi Oi « » N * UI «O U »ISUIUIU*Osl»*MlOKIOi M (Ti M KIMMMUI*>MMUMOi*Ja>UMWO>0> *J KI U «JM O0*OOUiKIOOO*JOUiOKI -J -J O O O -JOin*MO9>*OUlOUlKI*0W-JMWO*0a>Ul*>-J-J9> *> *J M O «O O O O O O O O oooooooooooooo M U *• o o o o o OOOOOOOOOOOOOOOOOOUIOOOKtOO o o o

M M * UI O* KI «O KiNHHUIOiNH»»NsJCDUH0< sl (h UI O H ^ KI * OI N N *> O M U U *> O o o o o o OOOOOOOOOOOOOOOOOOUIOOOKIOO o o o o o o oooooooooooooo o o o Table XX continued

134 137 PROVJXCE riSH Cm c. LAKE SPECIES n X • In max X • In • ax

ORIVESI BREAM 2 6.7 5.5 7.9 40 34 45 PIRCH 4 13 10 15 92 82 100 PIKE 2 13 9.7 17 95 80 110 PIKE-PERCH 2 1» 17 20 120 120 120 ROACH 2 2.9 2 3.8 21 17 25 VZNDACE 1 2.7 2.7 2.7 21 21 21 WHITEPISH 1 5.2 5.2 5.2 28 28 28

TURKU AND FORI

KYRÖSJXRVI BREAM 8 54 26 98 260 150 410 BURBOT 11 270 160 480 1300 820 2200 IDE 1 46 46 46 220 220 220 PERCH 27 160 62 390 720 350 1900 PIKE 16 240 120 4 60 1100 5B0 2000 VEKDACE 5 34 30 38 170 160 180 PYHXJXRVI PERCH 1 58 58 58 310 310 310

UUSIMAA

LOHJAJXRVI PERCH 2 3.3 1.6 5 15 10 20 VHITE BREAM 1 0* 0 0 5.4 5.4 5.4

below the detection limit

61 Table XXI. The average activity concentratlona (x) and the variation In Ca and Ca (Bq/kg frash weight) in various fish species in lakes with a surface area ••tiler than 20 km but larger than 1 k» (class 3) in 19Ö9. The nuaber of aaaples is also given (n).

13 PROVINCE FISH

HXME

KATUMAJXRVI BREAM 1 19 19 19 91 91 91 PERCH 1 81 81 81 390 390 390 PIKE 2 100 87 120 4 60 410 500 ROACH 2 27 20 33 ISO 110 180 VENDACE 2 32 14 49 150 76 220 KEIHXSJXRVI BURBOT 1 440 440 440 1900 1900 1900 PIKE 1 570 570 570 2700 2700 2700 KERTEJXRVI BREAM 2 130 120 140 680 580 770 BURBOT 1 850 850 850 3700 3700 3700 PERCH S 390 240 590 1800 1200 2600 PIKE 1 700 700 700 3100 3100 3100 ROACH 2 110 100 120 510 480 540 VENDACE 1 74 74 74 360 360 360 M1ESTXMX VENDACE 1 230 230 230 1100 1100 1100 MYLLYJXRVI BURBOT 1 2300 2300 2300 11000 11000 11000 PERCH e 1000 570 1900 5300 3000 9600 PIKE S 2000 1600 2200 8600 6400 11000 ROACH 1 440 440 440 2300 2300 2300 PXXJXRVI PERCH S 44 27 60 220 150 300 PIKE 1 120 120 120 550 550 550 ROACH ] 16 16 16 72 72 72 RAIMIOJXRVI IDE J 27 27 27 120 120 120 PERCH I 970 630 1300 4200 2800 5700 PIKE ] 2200 2200 2200 8900 8900 8900 RUUHIJXRVI PERCH ] 270 270 270 1400 1400 1400 ROACH ] 78 78 78 330 330 330 RUFF 1 53 53 53 260 260 260 VEHKAJXRVI BURBOT 1 3100 3100 3100 14000 14000 14000 PERCH ;! 1900 1600 2200 8400 7200 9600 PIKE : 2800 2800 2800 12000 12000 12000 ROACH 1100 1100 1100 4700 4700 4700 VENDACE L 1200 1200 1200 5000 5000 5000 YLÖJXRVI PIKE ) 1100 760 1300 4400 3100 5100

CENTRAL FINLAND

HEITJXRVI PERCH L 560 560 560 2800 2800 2800 PIKE I 380 380 380 1800 1800 1800 ROACH I 75 75 75 400 400 400 ISO-LÖYTXNX PIKE L 180 180 180 870 870 870 ISO-SUOJXRVI PIKE 1 390 390 390 1800 1800 1800 UHITEFISH 1 74 74 74 310 310 310 ISO-UURAINEN BREAH t 120 120 120 670 67 0 670 PIKE 1 190 190 190 970 970 970 JXMSXNVESI PERCH 2 61 53 69 340 290 380 PIKE 1 56 56 56 280 280 280 ROACH 1 22 22 22 130 130 130 KIIHASJXRVI PIKE 1 360 360 360 1600 1600 1600 KIMINCINJÄRVI BREAM 2 46 33 59 230 160 310 BURBOT 1 270 270 270 1200 1200 1200 IDE 1 28 28 28 140 140 140 PERCH 9 140 70 250 740 350 1200 PIKE 2 120 98 140 580 530 630 ROACH 2 33 30 36 170 160 180 UHITEFISH 2 67 66 67 350 350 360 KYYJXRVI BREAM S 48 37 58 230 180 280 IDE 2 39 37 41 180 180 180 PERCH 1 0 160 58 320 790 320 1400 PIKE < 160 120 210 770 600 910 ROACH 3 32 30 34 160 ISO 170 LUHPEROINEN BREAM 1 45 45 45 220 220 220 PERCH 2 310 190 430 1600 940 2200 PIKE 1 210 210 210 1100 1100 1100 ROACH 1 71 71 71 330 330 330 MAHLUNJXRVI PIKE 1 190 190 190 900 900 900 ROACH 1 51 51 51 250 250 250 NAARAJXRVI BURBOT 1 190 190 190 900 900 900 PETXJXVESI BREAM 1 57 57 57 250 250 250 PERCH 2 91 84 97 410 370 450 PIKE 1 140 140 140 600 600 600 ROACH 1 41 41 41 170 170 170

62 ooooooooooooooo ooooooooooooooo m ?H r. n « r*oooo«or*coo CO coooor*

OOOOOOOOOOOOOOO OOOOOOOOOOOOOO oooo»«n»o » H h n » ro r> r- o* H H H eoooo«H«ooor-oomoo*o moooooooor-oooo •» •» tn t* ONOtr^intHOOoointHOv1 i*if*)>-t «-< «-«N nm

OOOOOOOOOOOOOOO ooooooooIUVWWVUWW«JOOOOo Q Moooom^too coooo«ooto tnooooooootoooooooor-ooooi o CO CO CO C* O» N rt H •Vl-rtrtVVrt'OVinr-COfnOt*' tr4Nr«infnoino(0intHO«r« » t n h «O^^rtrtrtM» •» «n f* rt rt

o* o* co o* i n «*i « r- oooo^rtoooooooom ooooooooooooooo rt^Oineo<7*eor>rtOtn«oooo* r-oooo^m^or-oooe*»-* r- M »-« n . rtt*OM Minrtrtinrttn* rtinino^inMr-inrtOf^'OWN

»O »ID oooocortoor-ooooom ooooooooooooooo M rt »n rt rtvoonr^otvr^^oninioiooo) r^ovmo-vmtomr^oooc*^ r-« r> «o N ri r* N m H «n H rtintintriNnoHOh

<0 (MD »O rt «n o* r* OOOOrtrtOO r>ocoooommor>ooo<7i^> ri MD N Min <* m ** c* m rtincort«(nNinrtrtor««ONn

r* r* T* r* t rtONninrtNmi C4 m C4 rl f~tr1C4t*4r1C4TlC*f>4i*rlr4t-lr4T* i rt N rt rt

w U M U u HO H U b. a. 0. z:x x rox x < r x xox x X X < U COX • E X i xx s x xx xx r DQ.B.II!IID.D.K liglli 0. Ot > 3 B B 0. a. a. B a. o. a. Kp.a.p.cQrtp.a.Ka.P>aep>a.n

i< rt rt o) at

a. en M > Table XXI continued

PROVINCE T1SH Cl Ca SPECIES Bin bin

KäYLIÖNJARVI PIKE 1 IS 18 IB 110 110 110 VAHOJARVI BURBOT 1 590 590 590 2600 2600 2600 FERCH 4 370 260 450 1B00 1200 2300 PIKE 2 540 330 750 2400 1500 3400 ROACH 1 120 120 120 630 630 630

UUSIMAA

BODOHJÄRVI PERCH 1 4.5 4.5 4.5 23 23 23 ENXJARVI PIKE-PERCH 1 5.9 5.9 5.9 36 36 36 KYTXJXRVI BREAM 2 1.6 1.5 1.7 8.8 8.5 9 PERCH 4 3 1.3 4.9 19 9.7 30 PIKE-PERCH 2 8.5 8 9 46 40 52 ROACH 1 4.5 4.5 4.5 21 21 21 TROUT 1 3.7 3.7 3.7 15 15 15 SAHAJXRVI PERCH 2 44 41 47 210 190 230 VALKERPYY PERCH 2 3.7 2.7 4.6 87 8.7 170 ROACH 1 3.2 3.2 3.2 13 13 13

ULLAVANJXRVI BREAM 2 76 39 110 360 210 510 BURBOT 1 240 240 240 1100 1100 1100 PERCH 3 110 77 150 5B0 530 670 PIKE 2 230 190 260 1000 920 1200

64 Tabic XXII. The average activity concentrationa (i) and the variation by province in Ca and Ca (Bq/kg freah weight) in varloua flah apeciea in lakea with a eurface area of leaa than 1 ki Iclau 4) in 1989. The number of eanplea ia alao given (n).

FISH Ca Ca SPECIES min Bin

BREAM S 310 92 1000 1400 480 4600 BURBOT 1 1100 1100 1100 5500 5500 5500 EEL 5 310 100 480 1500 520 2500 PERCH 59 950 210 5400 4700 1000 24000 PIKE 30 1400 330 4800 6400 1600 21000 ROACH 12 290 100 820 1400 540 3800 VENDACE 1 1300 1300 1300 5900 5900 5900 UHITEFISH 12 620 110 1200 2900 530 5300

CENTRAL FINLAND

BREAM 4 51 26 61 260 130 320 BURBOT 1 78 78 78 420 420 420 IDE 3 100 57 150 530 270 840 PERCH 10 210 120 450 1100 690 2200 PIKE 13 350 31 1900 1700 160 8800 ROACH 8 66 29 88 340 140 470 UHITEFISH 1 120 120 120 570 570 570

KYMI

BREAM 31 25 36 150 130 160 PERCH 430 49 1100 2000 280 4800 PIKE 450 95 930 2000 480 4000 ROACH 140 29 320 700 140 1400 UHITEFISH 210 180 240 980 950 1000

MIKKELI

PERCH 200 56 370 1000 280 1900 PIKE 290 200 430 1400 1100 1900 ROACH 150 130 170 690 640 740

TURKU AND PORI

PERCH 160 83 270 780 390 1300 PIKE 220 86 390 1000 400 1700 ROACH 46 31 61 220 140 290

BREAM 11 11 11 46 46 46 PERCH 24 12 36 130 66 190 PIKE 51 19 97 260 100 500 ROACH 13 11 15 70 57 88

VAASA

PERCH 2 120 110 130 600 500 700 PIKE 1 130 130 130 630 630 630 ROACH 1 47 47 47 230 230 230

ALAND

250 230 1300 Table XXIII. The average activity concentrations (x) and the variation In Ca and Cj (Sq/kg freah weight) In various fiah species In the largest lakes (surface area > B90 km , class 1) In Finland in 1990. The number of samplea la alao given (n).

PROVINCE FISH Ca Ca SPECIES Din fflln

HXME

PXljXnNE BREAM 1 69 69 69 470 470 470 BURBOT 2 330 230 430 2100 1500 2700 PERCH 2 150 130 1B0 990 aso 1100 PIKE 2 190 120 260 1200 B00 1500 ROACH 2 73 51 95 460 350 570 WHITEFISH 2 43 42 43 300 300 310

CENTRAL FINLAND

PXIJXNNE BREAM 4 5B 19 130 3B0 130 B10 BURBOT 3 2B0 140 390 1B00 860 2400 PERCH 6 160 67 340 1000 420 2100 PIKE 4 160 9B 230 1000 700 1500 PIKE-PERCH 1 160 160 160 1100 1100 1100 ROACH 4 55 27 99 340 160 5B0 TROUT 1 55 55 55 330 330 330 UHITEFISH 4 36 22 S3 240 160 340

KALLAVESI BREAM 1 8 8 B 52 52 52 BURBOT 2 35 30 39 230 210 240 PERCH 4 26 21 32 170 140 200 PIKE 2 25 20 29 170 150 ISO PIKE-PERCH 1 17 17 17 140 140 140 VENDACE 1 3.5 3.5 3.5 29 29 29

KYHI

SAIMAA BURBOT 1 79 79 79 510 510 510 PERCH 2 65 26 100 440 220 670 PIKE 1 75 75 75 470 470 470 ROACH 2 21 15 26 150 120 170 VEHDACE 1 9 9 9 74 74 74 UHITEFISH 2 19 11 26 120 71 170

BREAM 2 3.7 3.4 4 25 24 26 PERCH 4 6.1 5 B.6 43 34 54 PIKE 1 B 8 B 55 55 55 ROACH 2 16 4 2B 120 25 220 RUDD 1 1.3 1.3 1.3 13 13 13

66 Table XXIV. The average activity concentration» (i) and the variation in C« and C» (Bq/kg freah weight) in varloua fish speciaa in lakea with a surface area of •ore than 20 km (claaa 2) in 1990. The area of Boat of the lakea In thla dan exceeda 100 ka . The nuaber of iiLplai ia alao given (n).

PROVINCE FISH 13

HXHE

KUOHUXRVI BURBOT 1 320 320 320 2000 2000 2000 PERCH 3 360 110 730 2500 SS0 5100 ROACH 1 56 56 56 440 440 440 WHITEFISH 1 88 88 88 6B0 680 6B0 NXSUXRVI BREAM 1 61 61 61 3B0 380 3B0 BURBOT 1 430 430 «30 2600 2600 2600 PERCH 2 370 330 400 2200 2000 2400 PIKE 1 630 630 630 3700 3700 3700 PIKE-PERCH 1 410 410 410 2600 2600 2600 ROACH 1 76 76 76 450 450 450 WHITEFISH 1 120 120 120 710 710 710 PXLKXNEVESI BREAM 1 15 15 15 84 84 84 PERCH 3 45 25 79 300 160 530 PIKE 1 34 34 34 290 290 290 ROACK 2 11 9.4 13 80 66 93 PYHXJXRVI BREAM 2 13 11 15 84 6B 99 (PIRKKALA) BURBOT 1 80 80 80 560 560 560 PERCH 2 50 35 65 320 240 400 PIKE 2 29 22 36 210 170 240 PIKE-PERCH 2 34 31 37 220 210 240 SILVER BREAM 2 15 12 17 91 83 98 WHITEFISH 1 29 29 29 200 200 200 PYHXjXRVI BREAM 2 3.9 2.8 5 28 23 32 (TAMMELA) BURBOT 2 10 10 10 72 71 72 PERCH 2 23 21 24 150 150 150 PIKE 2 13 8.1 17 91 65 120 PIKE-PERCH 2 13 10 16 87 69 110 ROACH 2 1.7 1.4 2 16 9.5 23 VANAJAVESI EEL 2 20 5 35 130 35 230 VESUXRVI BREAM 2 24 18 29 160 130 1B0 BURBOT 1 91 91 91 540 540 540 PERCH 1 95 95 95 600 600 600 PIKE 2 67 52 82 430 370 490 PIKE-PERCH 2 97 60 130 590 410 780 WHITEFISH 2 20 17 22 130 120 130

CENTRAL PIHLAHP

KEITELE BREAM 4 51 19 88 310 140 550 BURBOT 2 130 62 200 790 400 1200 PERCH 5 110 73 170 730 460 1000 PIKE 4 220 96 350 1400 670 2100 ROACH 3 79 63 110 540 410 690 VENDACE 1 38 38 38 260 260 260 KEURUSSELKÄ BURBOT 1 200 200 200 1200 1200 1200 PERCH 5 110 81 150 740 540 950 PIKE 2 140 120 170 940 820 1100 VENDACE 1 28 28 28 200 200 200 KIVuXRVI BURBOT 1 380 380 3B0 2400 2400 2400 PERCH 3 280 240 330 2100 1700 3000 PIKE 3 350 300 420 2300 2000 2900 aoACH 3 84 66 98 550 430 610 VENDACE 1 48 4B 48 380 380 3B0 WHITEFISH 1 67 67 67 490 490 490 SUONTEE BREAM 1 43 43 43 250 250 250 BURBOT 1 88 88 88 560 560 560 IDE 2 42 28 56 260 190 330 PERCH 6 120 69 260 780 490 1500 PIKE 2 130 92 170 860 640 1100 ROACH 3 44 3B 54 300 260 350 SMELT 1 27 27 27 170 170 170 WHITEFISH 1 37 37 37 220 220 220 VUOSjXRVI PERCH 2 150 140 150 930 880 9B0

KUOPIO

NILAKKA BREAM 1 35 35 35 280 280 2B0 BURBOT 2 200 100 290 1400 940 1800 PERCH 4 59 31 71 430 240 560 PIKE 2 180 86 260 1100 700 1600 ROACH 2 30 20 39 200 160 240 UHITEFISH 2 31 19 42 200 140 260 67 Tabic XXIV continued

PROVIHCE PISH 13

SORSAVESI BREAM 1 210 210 210 1200 1200 1200 PERCH 4 270 210 300 1B00 1500 2000 PIKE 2 630 570 700 3900 3700 4000 ROACH 2 B2 52 110 6B0 070 700 UHITEFISH 1 280 2S0 280 1800 1800 1800

KYMI

VUOHUXRVI BURBOT 2 150 120 180 690 270 1100 PERCH 3 160 71 240 1000 520 1600 PIKE 2 160 110 210 1000 800 1200 ROACH 2 83 34 130 550 260 850 VENOACE 1 24 24 24 180 180 1B0 WHITEFISH 1 19 19 19 140 140 140

MIKKELI

HAUKIVESI BREAM 1 17 17 17 130 130 130 BURBOT 1 110 110 110 790 790 790 PERCH 3 41 19 65 260 160 390 PIKE 2 96 42 150 620 310 930 VENDACE 1 15 15 15 100 100 100 UHITEFISH 1 16 16 16 110 110 110 KORPIJXRVI PERCH 4 60 28 76 460 240 620 PIKE 1 120 120 120 760 760 760 VENDACE 1 17 17 17 130 130 130 PURUVESI BREAM 1 29 29 29 210 210 210 BURBOT 1 120 120 120 730 730 730 PERCH 3 84 73 92 590 520 640 PIKE 2 98 43 150 740 530 960 ROACH 2 32 12 51 210 84 340 VENDACE 2 23 15 31 180 130 230 WHITEFISH 2 23 18 27 140 110 160 PUULA BREAM 2 25 23 27 190 170 220 BURBOT 2 81 77 84 540 510 570 PERCH 7 78 26 95 530 200 720 PIKE 2 87 68 110 580 460 690 PIKE-PERCH 1 B3 83 83 700 700 700 ROACH 1 16 16 16 110 110 110 SMELT 1 19 19 19 170 170 170 VENOACE 1 12 12 12 81 81 Bl UHITEFISH 1 12 12 12 110 110 110

NORTH KARELIA

ORIVESI BREAM 2 2.4 1.8 3 24 19 29 BURBOT 1 10 10 10 90 90 90 PERCH 3 5.B 3 7.3 65 42 88 PIKE 2 11 7.1 14 97 68 130 PIKE-PERCH 1 11 11 11 100 100 100 ROACH 1 0* 0 0 15 15 15 VENDACE 1 1.7 1.7 1.7 IB 18 18 UHITEFISH 1 1.8 l.B l.B 20 20 20

TURKU AND PORI

KYRÖSJXRVI BREAM 6 21 15 30 140 96 170 BURBOT 11 99 47 160 680 350 1100 PERCH 6 68 51 83 410 290 510 PIKE 19 84 47 160 530 340 1000 VENDACE 10 16 8.1 19 120 59 130 PYHXJRRVI PERCH 1 51 51 51 320 320 320 PIKE 1 31 31 31 210 210 210 ROACH 1 17 17 17 110 110 110 VENDACE 1 8 8 8 51 51 51 UHITEFISH 1 11 11 11 63 63 63

VAASA

LESTIJÄRVI PERCH 1 41 41 41 350 350 350 VENDACE 1 25 25 25 190 190 190

below the detection limit Tabic XXV. The average activity concentration!

PROVINCE FISH 134Ca l3 Ca LAKE SPECIES n x aln max x mln max

HXHE

ISO-RUUHUXRVI PERCH 2 S3 46 60 330 260 400 ROACH 1 32 32 32 200 200 200 KAARTJXRVI PERCH 1 61 61 61 370 370 370 KERTEJXRVI BREAM 1 120 120 120 810 810 810 BURBOT 1 790 790 790 4600 4600 4600 PERCH 6 190 120 350 1200 800 2200 PIKE 2 280 240 320 1700 1600 1900 ROACH 2 67 64 69 400 380 430 VHITEFISH 2 70 62 77 410 390 440 KUKKANEN PERCH 1 230 230 230 1500 1500 1500 MYLLYJXRVI PERCH 5 570 380 830 3900 2700 5500 PIKE 1 1000 1000 1000 7000 7000 7000 RAIMIOJXRVI IDE 1 13 13 13 79 79 79 PIKE 1 270 270 270 1700 1700 1700 URAJXRVI PERCH 2 170 140 200 1100 900 1200 PIKE 1 320 320 320 2000 2000 2000 VEHKAJXRVI PERCH 2 810 590 1000 4900 3700 6000 PIKE 1 990 990 990 5800 5800 5800 ROACH 1 490 490 490 3000 3000 3000 VENDACE 1 440 440 440 2600 2600 2600

CENTRAL FINLAND

ISDN LIITONJXRVI PIKE 1 81 81 81 650 650 650 KYYJXRVI BREAM 2 29 25 33 200 170 230 PERCH 3 98 66 ISO 660 400 1100 PIKE 2 100 79 120 630 520 740 PETXJXVESI BREAM 2 22 17 27 140 120 160 PERCH 3 88 58 110 570 370 750 PIK'i 2 77 58 96 480 390 570 ROi.'.H 1 42 42 42 280 280 280 VALKEAJXRVI PERCK 4 320 ISO 470 2500 1600 3100 PIKE 2 940 630 1200 5700 4000 7500

KUOPIO

ISO-II BREAM 2 1.9 1.8 2 17 15 18 PERCH 2 5.5 5 6 38 34 41 PIKE 1 8 8 8 52 52 52 PIKE-PERCH 1 4.4 4.4 4.4 41 41 41 VENDACE 1 1.9 1.9 1.9 19 19 19

MIKKELI

PIEKSXNJXRVI BREAM 1 150 150 ISO 910 910 910 BURBOT 1 780 780 780 5400 5400 5400 PERCH 3 360 210 600 2300 1400 3600 PIKE 2 470 350 590 2900 2400 3500 ROACH 1 130 130 130 950 950 950 VENDACE 2 140 120 170 950 840 1100 PYHXJXRVI BREAM I 180 180 ISO 1000 1000 1000 PERCH 3 370 270 440 2700 2500 2800 PIKE 2 530 520 540 3400 3200 3500 ROACH 2 220 200 240 1400 1300 1400 VENDACE I 110 110 110 900 900 900 VHITEFISH 1 230 230 230 1300 1300 1300 VANAJAJXRVI BURBOT 1 1000 1000 1000 6700 6700 6700 PERCH 2 420 410 420 2700 2600 2800 PIKE 2 380 350 400 2400 2000 2700 ROACH 2 180 170 200 1200 1100 1300 UHITEFISH 1 120 120 120 810 810 810

OULU

HYRYNJXRVI BURBOT 2 13 10 16 120 100 ISO PERCH 2 14 12 16 140 130 140 PIKE 2 6.9 5.7 8 75 69 81 ROACH 2 3.1 3 3.2 38 36 39 VENDACE 2 2.5 1.9 3 30 25 35 UHITEFISH 1 2.4 2.4 2.4 26 26 26

69 Table XXV continued

134 13? PROVINCE FISH C| C» LAKE SPECIES n x min max I min max

TURKU AND PORI

JXMIJXRVI BREAM 2 7.8 7.5 8 54 50 56 BURBOT 1 42 42 42 270 270 270 PIKE 1 37 37 37 220 220 220 PIKE-PERCH 2 66 50 81 410 340 470 KIRKKOJXRVI BREAM 1 0.5 0.5 0.5 4 4 4 PERCH 1 1.6 1.6 1.6 15 15 15 PIKE 1 2 2 2 16 16 16 PIKE-PERCH 1 2 2 2 14 14 14 VAHOJXRVI BURBOT 1 290 290 290 1700 1700 1700 PERCH 4 150 120 190 1100 880 1400 PIKE 2 210 150 270 1300 850 1800 ROACH 1 100 100 100 600 600 600 TROUT 1 0.19 0.19 0.19 2.3 2.3 2.3

UUSIMAA

ENXJXRVI PERCH 1 5.2 5.2 5.2 33 33 33 ROACH 1 3.3 3.3 3.3 21 21 21 KYTXJXRVI PERCH 4 2.5 1.7 4 17 12 26 ROACH 2 1.4 1.2 1.6 10 9.3 11 WHITE BREAM 1 1.8 1.8 1.8 6.6 6.6 6.6 NUMMIJÄRVI PERCH 1 8.9 8.9 8.9 58 56 58 VIHTUXRVI PERCH 1 14 14 14 100 100 100 VAASA

HALSUANJXRVI PIKE 1 53 53 53 390 390 390 RÄYRINGINJÄRVI PIKE 1 160 160 160 1100 1100 1100 SALAMAJÄRVI PIKE 1 560 560 560 3900 3900 3900 Table XXVI. Thj average activity concentration» {~i) and the variation by province In Cs and Cs (Bq/kg fresh weight) In various fish ipeclei In lakea with a surface area of less than 1 km (class 4) In 1990. The number of samples Is also given (n).

FISH 134C. 137C. SPECIES n x Bin B«i 5 min max

HXHE

BREAM 4 120 110 130 700 620 770 EEL 9 200 36 S00 1400 260 3500 PERCH 63 610 67 3400 4100 450 24000 PIKE 24 920 260 2200 6000 1600 15000 ROACH 12 ISO 67 460 970 440 3200 VHITEFISH 11 300 190 360 2000 1400 2400

KYMI

BREAM 2 18 17 19 120 110 130 BURBOT 1 88 88 88 550 550 550 PERCH 10 130 25 360 890 180 2300 PIKE 3 200 69 420 1200 460 2500 ROACH 5 77 18 190 510 130 1100 UH1TE BREAM 1 23 23 23 140 140 140 WHITEFISH 2 110 110 110 690 640 750

MIKKELI

PERCH 5 270 70 570 1900 480 4000 PIKE 3 150 100 200 1000 600 1400 ROACH 3 90 39 170 590 290 1100 RUFF 2 190 45 340 1200 290 2200

OULU

EEL 2 3.4 2.2 4.5 39 31 46

TURKU AND PORI

PERCH 2 92 71 110 600 530 660 PIKE 2 120 76 150 760 530 990 ROACH 1 32 32 32 200 200 200

UUSIMAA

PERCH 3 9.7 8.1 11 71 64 79

ROACH 1 6.2 6.2 6.2 50 50 50

ALAND

PERCH 3 110 62 160 800 490 1200 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

Table XXVII. Areal averages of 137Cs (Bq/kg fresh weight) in the three fish groups: (A) predators, (B) non-predators and (C) intermediate in 1988-1990. The number of samples is given in brackets. Countrywide averages, weighted for catches, for the same fish groups are also given.

Fishery Fish 1988 1989 1990 area group

1 A 360 (11) 260 (7) 550 (3) B 110 (14) 70 (12) 90 (12) C 300 (17) 160 (22) 160 (16)

2 A 1 000 (4) 550 (5) 390 (4) B 260 (3) 110 (7) 70 (3) C 1 500 (3) 380 (6) 600 (6)

3 A 940 (29) 630 (31) 660 (23) B 590 (28) 190 (28) 170 (29) C 780 (43) 670 (44) 430 (36)

4 A 2 600 (73) 1 900 (104) 1 400 (60) B 640 (75) 400 (101) 400 (64) C 1 500 (105) 1 100 (147) 820 (98)

5 A 2 100 (130) 1 600 (96) 1 000 (90) B 430 (83) 290 (67) 200 (58) C 1 500 (146) 1 000 (140) 990 (150)

6 A 970 (9) 950 (4) 350 (4) B 350 (9) 320 (3) 190 (1) C 900 (14) 590 (5) 710 (1)

7 A 1 100 (30) 710 (25) 330 (4) B 170 (24) 230 (10) 150 (4) C 370 (39) 680 (29) 300 (5)

8 A 110 (37) 140 (28) 120 B 40 (14) 40 (13) 40 C 70 (91) 80 (51) 70

Whole Ä 1 300 98Ö 74Ö country B 410 220 180 C 860 650 520 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Table XXVIII. Areal and countrywide averages of 137Cs in fish (Bq/kg fresh weight), weighted for catches of different fish species, in 1988- 1990.

Fishery 1988 1989 1990 area

1 270 170 260 2 790 290 300 3 760 490 400 4 1 500 1 100 860 5 1 400 980 760 6 730 610 410 7 770 460 260 8 70 80 70

Whole 840 600 470 countiy FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

Table XXIX. The annual transfer factors from water to the three fish groups, (A) predators, (B) non-predators and (C) intermediate (Bq kg"; in fish/Bq kg"; in water) in different statistical fishery areas and in the whole country in 1986-1990.

Fishery Fish 1986 1987 1988 1989 1990 area group

1 A 400 23 000 8 400 6 700 22 000 B 1 200 1 300 2 600 1 800 3 600 C 1 500 2 500 7 000 4 100 6 400

2 A 1 600 18 000 25 000 18 000 20 000 B 1 400 9 800 6 300 3 700 3 500 C 1 900 30 000 35 000 13 000 30 000

3 A 200 10 000 17 000 14 000 21 000 B 600 8 000 11 000 4 200 5 300 C 400 17 000 14 000 15 000 13 000

4 A 600 6 000 13 000 14 000 15 000 B 800 2 300 3 200 2 900 4 200 C 1 100 5 700 7 400 7 600 8 500

5 A 700 6 100 13 000 13 000 12 000 B 700 2 300 2 600 2 400 2 300 C 1 200 6 100 9 300 8 700 11 000

6 A 300 7 700 13 000 16 000 9 500 B 600 3 200 4 800 5 400 5 100 C 1 700 8 500 12 000 10 000 19 000

7 A 200 6 200 16 000 17 000 9 400 B 400 3 300 2 500 5 300 4 300 C 400 4 700 5 400 16 000 8 600

8 A 1 300 10 000 7 900 12 000 11 000 B 900 3 900 2 900 3 300 3 600 C 1 500 7 800 5 000 6 700 6 400

Whole Ä" 2ÖÖ 8 700 16 000 16 000 17 000 country B 300 4 100 5 000 3 600 4 200 C 400 8 700 11 000 11 000 12 000

7A FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

Table XXX. Transfer factors from deposition to the three fish groups: (A) predators, (B) non-predators and (C) intermediate (Bq kg-1/Bq m"2) in different statistical fishery areas and in the whole country in 1986-1990.

Fishery Fish 1986 1987 1988 1989 1990 area group

1 A 0.013 0.15 0.026 0.019 0.040 B 0.037 0.0086 0.0079 0.0050 0.0065 C 0.047 0.017 0.022 0.012 0.012

2 A 0.039 0.091 0.084 0.046 0.032 B 0.035 0.049 0.022 0.0091 0.0058 C 0.046 0.15 0.12 0.031 0.050

3 A 0.012 0.14 0.14 0.096 0.10 B 0.036 0.11 0.089 0.029 0.026 C 0.021 0.24 0.12 0.10 0.065

4 A 0.025 0.069 0.085 0.064 0.046 B 0.032 0.027 0.021 0.013 0.013 C 0.043 0.066 0.048 0.035 0.027

5 A 0.036 0.063 0.067 0.050 0.033 B 0.039 0.024 0.014 0.0092 0.0063 C 0.063 0.063 0.048 0.033 0.031

6 A 0.012 0.066 0.064 0.063 0.023 B 0.021 0.028 0.023 0.021 0.013 C 0.064 0.072 0.059 0.039 0.047

7 A 0.013 0.21 0.30 0.19 0.087 B 0.024 0.11 0.045 0.061 0.039 C 0.024 0.16 0.097 0.18 0.079

8 A 0.043 0.12 0.073 0.093 0.080 B 0.030 0.047 0.027 0.027 0.027 C 0.049 0.093 0.047 0.053 0.047

Whole A 0.0096 0.12 0.12 0.092 0.069 country B 0.016 0.058 0.038 0.021 0.017 C 0.021 0.12 0.080 0.061 0.049

75 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

PUBLICATIONS BY THE FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY (STUK)

STUK-A reports:

STUK-A101 Toivonen M. Improved STUK-A93 Puhakainen M, Rahola T. processes :n therapy dosimetry with solid Radioactivity of sludge in Finland in LiF thermoluminescent detectors. Hcl- 1988-1990. Supplement 5 to Annual sinki, 1991. Report STUK-A89. Helsinki, 1991.

STUK-A100 Servomaa K. Biological STUK-A92 Klemola S, Uus E, Sjöblom effects of radiation: The induction of K-L, Arvela H, Blomqvist L. Monito- malignant transformation and program- ring of radionuclides in the environs of mcd cell death. Helsinki, 1991. the Finnish nuclear power stations in 1988. Supplement 3 to Annual Report STUK-A99 Ruosteenoja E. Indoor ra- STUK-A89. Helsinki, 1991. don and risk of lung cancer- an epide­ miological study in Finland. Helsinki, STUK-A91 Rahola T. Suomela M, 1991. Hiukka E, Pusa S. Radioactivity of people in Finland in 1988. Supplement STUK-A98 Kosunen A, Järvinen H, 2 to Annual Report STUK-A89. Hclsin- Vatnitskij S, Ermakov I, Chervjakov A, ki, 1991. Kulmala J, Pitkänen M, Väyrynen T. Väänänen A. Intercomparison of ra- STUK-A90 Saxen R, Ikäheimonen TK, diothcrapy treatment planning systems Uus E. Monitoring of radionuclides in using calculated and measured dose the Baltic Sea in 1988, Supplement 1 to distributions for external photon and Annual Report STUK-AS9. Helsinki electron beams. Helsinki, 1991. 1990.

STUK-A97 Lcvai F, Tikkincn J, Tar- STUK-A88 Valtonen K. BWR stability vainen M, Arit R. Feasibility studies of analysis. Helsinki, 1990. computed tomography in partial defect detection of spent BWR fuel. Heisin- STUK-A87 Scrvomaa A, Rannikko S, ki, 1990. Nikitin V, Golikov V, Ermakov I, Ma- sarskyi L and Saltukova L. A topo­ graphically anatomically unified phantom model for organ dose determination in radiation hygiene. Helsinki, 1989.

1 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

STUK-A86 Aro I. Studies on severe Supplement 5 to annual Report STUK- accidents in Finnish nuclear power A74. Helsinki, 1989. plants. Helsinki, 1989. STUK-A78 Rantavaara A. Radioactivity STUK-A85 Hoikkala M, Lappalainen of foodstuffs in Finland in 1987-88. J, Leszczynki K, Paile W. Väestön altis- Supplement 4 to Annual Reports STUK- tuminen ultraviolettisäteilylle Suomessa A74 and STUK-A89. Helsinki, 1991. ja säteilymittaukset. Helsinki, 1990. STUK-A77 Saxen R, Rantavaara A. STUK-A84 Puhakainen M, Rahola T. Radioactivity of surface water and fresh Radioactivity of sludge in Finland in water fish in Finland in 1987. Supp 1987. Supplement 10 to Annual Report lement 3 to Annual Report STUK-A74. STUK-A74. Helsinki, 1989. Helsinki, 1990.

STUK-A83 Uus E, Klemola S, Sjöbl- STUK-A76 Arvela H, Markkanen M, om K-L, Ikäheimonen TK. Radioacti- Lemmelä H, Blomqvist L. Environmental vity of along the finnish coast in 1987. gamma radiation and fallout measure- Supplement 9 to Annual Report STUK- ments in Finland, 1986-87. Supplement A74. Helsinki, 1988. 2 to Annual Report STUK-A74. Hel­ sinki, 1989. STUK-A82 Ikäheimonen TK, Uus E, Saxen R. Finnish studies in radioacti- STUK-A75 Saxen R, Aaltonen H, Ikä— vity in the Baltic Sea in 1987. Supple- heimonen TK. Airborne and deposited ment 8 to Annual Report STUK A- radioactivity in Finland in 1987. Supple- 74. Helsinki, 1988. ment 1 to Annual Report STUK-A74. Helsinki, 1990. STUK-A81 Rahola T, Suomela M, Hiukka E, Pusa S. Radioactivity of peo- STUK-A74 Suomela M, Blomqvist L, ple in Finland in 1987. Supplement 7 to Rahola T and Rantavaara A. Studies on Annual Report STUK-A74. Helsinki, environmental radioactivity in Finland 1989. in 1987. Annual Report. Helsinki, 1991.

STUK-A80 Rissanen K, Rahola T, II- STUK-A73 Järvinen H, Bregazde JI, lukka E, Alftan A. Radioactivity in rein- Berlyand VA, Toivonen M. Comparison deer, game, fish and plants in finnish of The National Standards for the mea- Lappland in 1987. Supplement 6 to An- surements of absorbed dose at ^Co gam- nual Report STUK-A74. (to be pub- ma radiation. Helsinki, 1988. lished in 1991) STUK-A72 Keskitalo J. Effects of ther- STUK-A79 Sjöblom K-L, Klemola S, mal discharges on the benthic vegeta- llus E, Arvela H, Blomqvist L. Monito- tion and phytoplankton outside the Olki- ring of radioactivity in the environs of luoto nuclear power station, west coast finnish nuclear power stations in 1987. of Finland: summary. Helsinki, 1988.

2 FINNISH CENTRE FOR RADIATION STUK-A94 AND NUCLEAR SAFETY

STUK-A71 Keskitalo J. Effects of ther- Chernobyl accident in 1986. Supple- mal discharges on the benthic vegeta- ment 10 to Annual Report STUK-A55. tion and phytoplankton outside the Olki- Helsinki, 1987. luoto nuclear power station, west coast of Finland. Helsinki, 1988. STUK-A64 Rahola T, Suomela M, Hiukka E, Puhakainen M, Pusa S. Ra- STUK-A70 Hellmuth K-H. Rapid de- dioactivity of people in Finland after the termination of strontium-89 and stron- Chernobyl accident in 1986. Supplement tium-90 -experiences and results with 9 to Annual Report STUK-A55. Hel- various methods after the Chernobyl sinki, 1987. accident in 1986. Helsinki, 1987. STUK-A63 Rissanen K, Rahola T, II- STUK-A69 Salmenhaara S, Tarvainen lukka E, Alfthan A. Radioactivity of M. Nondestructive measurements with reindeer, game and fish in Finnish Lap- a WWER-440 fuel assembly model land after the Chernobyl accident in using neutron and gamma sources. Hel- 1986. Supplement 8 to Annual Report sinki, 1987. STUK-A55. Helsinki, 1987.

STUK-A68 Puhakainen M, Rahola T, STUK-A62 Rantavaara A, Nygren T, Suomela M. Radioactivity of sludge af- Nygren K, Hyvönen T. Radioactivity of ter the Chernobyl accident in 1986. game meat in Finland after the Cher- Supplement 13 to Annual Report STUK- nobyl accident in 1986. Supplement 7 to A55. Helsinki, 1987. Annual Report STUK-A55. Helsinki, 1987. STUK-A67 Uus E, Sjöblom K-L, Aal­ tonen H, Klemola S, Arvela H. Mo- STUK-A61 Saxen R, Rantavaara A. nitoring of radioactivity in the environs Radioactivity of fresh water fish in Fin- of Finnish nuclear power stations in land after the Chernobyl accident in 1986. Supplement 12 to Annual Report 1986. Supplement 6 to Annual Report STUK-A55. Helsinki, 1987. STUK-A55. Helsinki, 1987.

STUK-A66 Uus E, Sjöblom K-L, Sa- STUK-A60 Saxen R, Aaltonen H. Ra- xen R, Aaltonen H, Taipale TK. Fin- dioactivity of surface water in Finland nish studies on radioactivity in the Baltic after the Chernobyl accident in 1986. Sea after the Chernobyl accident in 1986. Supplement 5 to Annual Report STUK- Supplement 11 to Annual Report STUK- A55. Helsinki, 1987. A55. Helsinki, 1987. STUK-A59 Rantavaara A. Radioactivity STUK-A65 Arvela H, Blomqvist L, of vegetables and mushrooms in Fin- Lemmelä H, Savolainen A-L, Sarkkula land after the Chernobyl accident in S. Environmental gamma radiation mea- 1986. Supplement 4 to Annual Report surements in Finland and the influence STUK-A55. Helsinki, 1987. of the meteorological conditions after the

3 FINNISH CENTRE FOR RADIATION AND NUCLEAR SAFETY STUK-A94

STUK-A58 Rantavaara A, Haukka S. STUK-A50 Järvinen H, Rannikko S, Radioactivity of milk, meat, cereals and Servomaa A. Report on the Nordic- other agricultural products in Finland Soviet meeting on standard and applied after the Chernobyl accident in 1986. dosimetry, Helsinki, 9-11 November Supplement 3 to Annual Report STUK- 1983. Helsinki, 1984. A55. Helsinki, 1987. STUK-A49 Tarvainen M, Riihonen STUK-A57 Saxen R, Taipale TK, Aal- M. Spent fuel measurements at Loviisa tonen H. Radioactivity of wet and dry nuclear power station. May, 1982. deposition and soil in Finland after the Helsinki, 1984. Chernobyl accident in 1986. Supp­ lement 2 to Annual Report STUK-A55. Helsinki, 1987. The full list of publications is available from: STUK-A56 Sinkko K, Aaltonen H, Tai­ pale TK, Juutilainen J. Airborne ra- Library dioactivity in Finland after the Cher- Finnish Centre for Radiation nobyl accident in 1986. Supplement 1 to and Nuclear Safety Annual Report STUK-A55. Helsinki, P.O. BOX 268 1987. SF-00101 HELSINKI Finland STUK-A55 Studies on environmental radioactivity in Finland in 1986. Annu­ al Report. Helsinki, 1987.

STUK-A54 Studies on environmental radioactivity in Finland 1984-1985. Annual Report. Helsinki, 1987.

STUK-A53 Järvinen H, Rantanen E, Jokela K. Testing of radiotherapy dosi­ meters in accordance with IEC speci­ fication. Helsinki, 1986.

STUK-A52 af Ekenstam G, Tarvainen M. Independent bumup verification of BWR-type nuclear fuel by means of the 137Cs activity. Helsinki, 1987.

STUK-A51 Arvela H, Winqvist K. Influence of source type and air ex­ change on variations of indoor radon concentration. Helsinki, 1986.

4 SÄTEILYTURVAKESKUS S'raisakerhetscentraien Finnish Centre for Radiation and Nuclear Safety