Cesium 137 Contamination of Wild Boars

Wild boars show elevated caesium 137 activities in some areas in GermanyIn the months following the deposition of radiocesium from the Chernobyl fallout, levels ranging from a few becquerels of Cesium 137 per kilogram to several thousand becquerels per kilogram were measured in wild boar meat in Germany.
In 2020, the range of Cs 137 contamination in wild boar is still as wide, and maximum levels in some regions are higher today than in 1986.
One phenomenon is of particular importance: the large differences in radiation levels in wild boar occur not only between different regions in Germany, but also in areas more highly contaminated by Chernobyl fallout.
For example, it is also possible to have 2020 samples of wild boar from the same hunting ground simultaneously below 100 Bq Cs 137 per kg but also of several thousand Bq/kg. In addition, large seasonal variations in contamination can also occur in an area.

Up to date overview in Germany

The effects of the Chernobyl accident are limited after more than 30 years in Germany. However, the authorities are still concerned about the radioactivity of wild boars and some species of mushrooms. From a radiobiological point of view, only cesium-137 is relevant today. Foodstuffs from agricultural areas largely exhibit radiocesium activities, which were also measured before the reactor accident. However, due to special transfer processes in forest ecosystems, elevated cesium-137 contamination occurs here in some biomedia.

Deer truffles accumulate the nuclide to a particular degree. And since wild boars are particularly fond of eating these mushrooms, this leads to increased caesium-137 radiation exposure in wild boars. However, since wild boar do not consume deer truffles in equal quantities throughout the year and the truffles also fructify differently depending on the season, the whole thing is very dynamic. Here you can find information and measured values on the Cs 137 contamination of deer truffles.

Research Project “Assessment of contamination levels of wild boar (Sus scrofa) in Germany“

Project duration: 01.10.2017 – 31.01.2021, researcher: umweltanalysen.com. On behalf: Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU). Data Source: doris.bfs.de/jspui/bitstream/urn:nbn:de:0221-2020100623424/3/BfS_2020_SCHR_66-20.pdf

Sus scrofa (wild boar) is the only animal species that, even 30 years after the Chernobyl fallout, still has significantly increased Cs-137 contamination in some areas of the Federal Republic of Germany. The variability of the Cs-137 measured values both within and between different populations is very large. Deer truffles are the main source of contamination. In this research project, the contamination situation of wild boars is to be evaluated over a period of 3 years using current data from 3 study areas (Bodenmais, Dahn and Zusmarshausen). The project is divided into 3 work packages (WP):

  • – Collection of information on hunting range and shooting weights (WP1)
  • – Sampling and measurement of deer truffles in the study areas (WP2)
  • – Sampling and measurements on muscle meat samples from wild boars (WP3).

Implementation WP3

 Wild boar – sample processing and Cs-137 activity determination

The 3 forestry departments were provided with packaging material for the dispatch of the wild boar muscle flesh samples. The following data were recorded for each wild boar hunted: forest office, hunt date, hunted class, sex, type of hunt and hunt weight [kg]. The thawed muscle meat was homogenized and weighed into 120 ml measuring vessels. The samples were measured on pure germanium detectors. The measurement times were 6 to 24 hours, depending on the activity of the sample.

Results

From September 1st, 2017 to December 31st, 2019, muscle meat samples from 376 wild boars were delivered by the forest services (Bodenmais 129, Dahn 123 and Zusmarshausen 124). So far, 355 samples have been measured for Cs-137 activity. The Cs-137 contamination of wild boars fluctuated seasonally depending on the availability of individual food components within a study area, with the variability of the measured values being up to three orders of magnitude. The values ranged from 0.6 Bq/kg fresh mass (FM) (Dahn) to 16,704 Bq/kg (Bodenmais). The median of the measured values of 2,857 Bq/kg in Bodenmais shows the significantly higher Cs-137 contamination of the wild boar population compared to Dahn with 7.5 Bq/kg and Zusmarshausen with 118 Bq/kg. In the mast years, wild boars were significantly less contaminated than in the years without large amounts of fruits of beech and oak.

 

Cesium 137 readings 2020

Radioactive measurements on meat samples of wild boar from Bavaria are carried out by the Bavarian State Office for the Environment and Food Safety, among others. For 2020, the following results are published on the website of the LfU (Table 1). With regard to the measured Cs 137 activities, it should be noted that it is predominantly meat from animals that have been officially placed on the market. Accordingly, the values are below the 600 Bq limit. In southern Germany, regionally significantly higher caesium contamination levels are measured in wild boar, in some cases up to 10,000 Bq/kg. These animals are not traded, they are disposed of.

Radioactivity measurements at the laboratory for radioisotopes at the University of Göttingen

Since April 1986 the author has investigated the radioactive contamination of wild animals in various research projects. Unless otherwise indicated, all measurements for radioactivity were carried out in the Laboratory for Radioisotopes at the University of Göttingen. The LARI has a non-nuclide-specific handling permit and can therefore measure radioactive substances within the limit values of activity class SK2.

Wild boar cesium 137 contamination in 1986

In the following table measured values of radiocesium activity of wild boars from Germany from 1986 to 1987 are given. The data were collected at the former Institute for Wildlife Biology and Hunting Science at the University of Göttingen. The measurements were made at the former Isotope Laboratory of the University of Göttingen (now the Laboratory for Radioisotopes). Measured values in fresh weight (FW).

Date of shooting Place of shooting Cs-134 Cs-137
[Bq/kg FW] [Bq/kg FW]
04.06.1986 Hannoversch Münden 56 120
07.06.1986 Fintel 42 84
12.06.1986 Hammelburg 12 25
18.06.1986 Nörten Hardenberg 61 131
22.06.1986 Prezelle 249 526
25.06.1986 Wriedel 23 65
29.06.1986 Gleichen 15 29
01.07.1986 Bad Lauterberg 179 381
02.07.1986 Hannoversch Münden 100 194
02.07.1986 Hannoversch Münden 86 188
03.07.1986 Weil 42 83
08.07.1986 Gleichen 35 66
09.07.1986 Hannoversch Münden 49 103
09.07.1986 Hannoversch Münden 55 103
11.07.1986 Hannoversch Münden 100 194
12.07.1986 Bad Soden-Allendorf 25 44
14.07.1986 Rosdorf 64 134
14.07.1986 Hofgeismar 112 237
14.07.1986 Detmold 116 237
16.07.1986 Hannoversch Münden 116 189
16.07.1986 Hannoversch Münden 116 189
21.07.1986 Bühren 31 52
06.08.1986 Kehlheim 19 79
14.09.1986 Saumslek 30 64
20.09.1986 Gleichen 12 26
23.09.1986 Bargteheide 6 14
24.09.1986 Hardegsen 17 55
27.10.1986 Einbeck 29 64
16.11.1986 Reinhardshagen 90 216
16.11.1986 Reinhardshagen 92 237
16.11.1986 Reinhardshagen 91 221
16.11.1986 Reinhardshagen 142 343
16.11.1986 Reinhardshagen 89 225
16.11.1986 Reinhardshagen 103 271
14.12.1986 Nörten Hardenberg 5 10
15.12.1986 Springe 29 69
15.12.1986 Springe 16 41
15.12.1986 Springe 34 77
15.12.1986 Springe 42 104
15.12.1986 Springe 28 77
15.12.1986 Springe 16 37
15.12.1986 Springe 28 70
15.12.1986 Springe 19 44
15.12.1986 Springe 15 32
27.01.1987 Dassel 58 154
27.01.1987 Dassel 42 99
22.06.1987 Friedland 4 18
24.06.1987 Rosdorf 26 59
24.06.1987 Rosdorf 15 29
17.08.1987 Bodenmais 1.062 3619
26.08.1987 Gleichen 0 10
01.10.1987 Bodenmais 925 3020
04.10.1987 Bodenmais 982 4602
08.10.1987 Bodenmais 839 2699
31.10.1987 Kelheim 4 22
22.11.1987 Bodenmais 1455 5425
03.12.1987 Gartow 17 56
10.12.1987 Kassel 13 58
11.12.1987 Bodenmais 278 973
06.01.1988 Gartow 12 43
11.02.1988 Gartow 8 29
23.03.1988 Gartow 1 6
06.07.1988 Bodenmais 590 2284
15.07.1988 Bodenmais 408 1668
29.07.1988 Fuhrberg 5 26
21.08.1988 Fuhrberg 4 27
26.08.1988 Fuhrberg 2 8
29.08.1988 Fuhrberg 8 40
28.09.1988 Fuhrberg 24 118
28.09.1988 Fuhrberg 7 33
11.10.1988 Fuhrberg 16 85
26.10.1988 Fuhrberg 11 53
30.10.1988 Fuhrberg 6 33
08.11.1988 Bodenmais 306 1306
18.11.1988 Fuhrberg 25 134
19.11.1988 Bodenmais 143 653
21.11.1988 Fuhrberg 5 22
22.11.1988 Fuhrberg 6 34
22.11.1988 Fuhrberg 4 21
22.11.1988 Fuhrberg 9 53
23.11.1988 Fuhrberg 5 22
23.11.1988 Fuhrberg 5 26
30.01.1989 Fuhrberg 26 138
30.01.1989 Fuhrberg 5 29
30.01.1989 Fuhrberg 5 30
09.05.1989 Bodenmais 6 30
09.05.1989 Bodenmais 6 32
18.05.1989 Bodenmais 470 2433
31.05.1989 Bodenmais 316 1762
16.07.1989 Bodenmais 410 2046
31.10.1989 Bodenmais 781 4991
07.12.1989 Bodenmais 384 2469
07.12.1989 Bodenmais 251 1762

Wild boar Cs 137 contamination in Japan – Fukushima accident

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011 released large amounts of man-made radioactive substances into the environment. In a study of radiocesium levels in wild boars in Japan, Cui et. al (2020) measured the concentration of Radiocesium (Cs 134 + Cs 137) in 213 muscle samples from wild boar (Sus scrofa) caught in the town of Tomioka, which is 20 km from the FDNPP. The results show that 210 (98.6%) muscle samples still exceed the regulatory Radiocesium limit (100 Bq/kg) for general foods. Radiocesium values (Cs 134 + Cs 137) were between 87.1 and 8,120 Bq/kg fresh mass (FM) with a mean concentration of 450 Bq/kg FM. The distribution of the radiocesium activity is shown in Figure 3.

Literature

Agentur für Gesundheit und Ernährungssicherheit: Cäsium 137-Belastung von Wildfleisch in Österreich

Cui, L., Orita, M., Taira, Y., Takamura, N., 2020: Radiocesium concentrations in wild boars captured within 20 km of the Fukushima Daiichi Nuclear Power Plant. Sci Rep 10, 9272 (2020). https://doi.org/10.1038/s41598-020-66362-6. Link zur Quelle

Fielitz U., 2005: Untersuchungen zum Verhalten von Radiocäsium in Wildschweinen und anderen Biomedien des Waldes

Fielitz U., 1996: Radiocäsium in Wildtieren nach dem Reaktorunfall von Tschernobyl

Hartmann, P., Urso, L., Fielitz, U., Steiner, M., 2016. A probabilistic/stochastic model for contamination levels of Cs-137 in Wild Boars. In: IRPA conference. Cape Town. 9-13 May 2016.

Rachubik J., 2008: Radiocesium in Polish game meat

Radioactive wild boars in Sweden are eating nuclear mushrooms

Tataruch F., Schönhofer F., Onderscheka K., 1988: Untersuchungen zur radioaktiven Belastung der Wildtiere in Österreich