The Enigma of Radioactive Wild Boars Finally Unraveled by Scientists

by Tatsuya Nakamura
Radioactive Wild Boars

Recent studies have revealed that the continuous radioactive contamination in wild boar meat in Central Europe, initially attributed to the Chernobyl disaster, is also heavily influenced by cesium from nuclear weapons tests in the 1960s. This discovery underscores the intricate ecological dynamics and the importance of accurate scientific investigation. Acknowledgment: Joachim Reddermann / TU Wien

Years after the Chernobyl nuclear catastrophe, wild boar meat in Central Europe is still showing surprising levels of radioactivity. The mystery has been solved: a significant overlooked factor is contributing to this phenomenon.

The Chernobyl incident in 1986 profoundly affected the region’s forest ecosystems. Following the disaster, high levels of radioactive contamination led to warnings against consuming certain forest foods, including wild game. While radioactivity in deer and roe deer meat eventually decreased as anticipated, wild boar meat has consistently shown higher than expected levels of radioactivity, at times surpassing safety standards even today.

This ongoing anomaly, referred to as the “wild boar paradox,” puzzled experts for many years. However, recent in-depth research by TU Wien (Vienna) and the Leibniz University of Hannover has provided a solution: it is a delayed effect of the 1960s nuclear weapons testing.

Can radiation exceed theoretical limits?

According to Prof. Georg Steinhauser of TU Wien, cesium-137 is the primary contributor to the samples’ radioactivity, with a half-life of approximately 30 years. Ordinarily, radiation in food decreases much faster than the natural decay rate of cesium.

Since Chernobyl, cesium has been dispersed, washed away by rain, bonded to minerals, or moved deep into the soil, reducing its absorption by plants and animals. Therefore, after one half-life, food typically shows much less than half the original activity concentration.

However, the situation with wild boar meat is different: radiation levels have remained nearly constant, declining much slower than the natural decay rate of cesium would suggest, a finding initially seeming contradictory from a physical standpoint.

Currently, some wild boar meat samples are still too radioactive for consumption, exceeding allowable limits. This has also led to reduced hunting of wild boars in certain areas, contributing to their overpopulation and associated agricultural and forestry damage.

Tracing the cesium’s origin

Prof. Georg Steinhauser, who moved from Leibniz Universität Hannover to TU Wien in 2022, along with his team, aimed to unravel this mystery by conducting new, more accurate measurements to determine the radioactivity’s amount and source.

Dr. Bin Feng from the Institute of Inorganic Chemistry at Leibniz Universität Hannover and the TRIGA Center Atominstitut at TU Wien explains that different sources of radioactive isotopes have distinct physical signatures. They release not only cesium-137 but also cesium-135, with a much longer half-life. The ratio of these cesium types varies, providing clues about the radioactive material’s origin.

Accurately measuring cesium-135 is challenging due to its long half-life and infrequent decay. Advanced mass spectrometric methods are needed for precise differentiation. This has now been achieved successfully.

The findings indicate that while around 90% of Central Europe’s cesium-137 originates from Chernobyl, a significant portion in wild boar meat comes from 1960s nuclear weapons testing, reaching up to 68% in some samples.

Deer truffles – a contributing factor

Wild boars’ dietary preference for deer truffles, subterranean mushrooms, plays a key role in this scenario. These truffles accumulate radioactive cesium with a considerable delay. As cesium moves slowly through the soil, sometimes just one millimeter per year, deer truffles at depths of 20-40 centimeters are only now absorbing Chernobyl-released cesium, while the cesium from older nuclear tests reached these depths earlier.

This situation reflects a complex interplay of factors: the spread of cesium from both nuclear tests and Chernobyl through the soil, reaching the truffles, and the natural decay of cesium over time.

Adding up these effects helps explain why the radioactivity in deer truffles – and consequently in wild boars – has remained relatively stable over the years. Thus, a significant reduction in wild boar meat contamination is not anticipated soon, as Chernobyl’s cesium is only now being integrated into the truffles. Georg Steinhauser emphasizes the complexity of natural ecosystems and the ability to solve such mysteries with sufficiently precise measurements.

Reference: “Disproportionately High Contributions of 60 Year Old Weapons-137Cs Explain the Persistence of Radioactive Contamination in Bavarian Wild Boars” by Felix Stäger, Dorian Zok, Anna-Katharina Schiller, Bin Feng and Georg Steinhauser, 30 August 2023, Environmental Science & Technology.
DOI: 10.1021/acs

Frequently Asked Questions (FAQs) about Radioactive Wild Boars

What is the “Wild Boar Paradox” and what causes it?

The “Wild Boar Paradox” refers to the persistent high levels of radioactivity found in wild boar meat in Central Europe, long after the Chernobyl disaster. Recent studies have revealed that this is not only due to Chernobyl’s fallout but also significantly influenced by cesium from 1960s nuclear weapons tests. This complex situation results from cesium’s slow soil migration and the dietary habits of wild boars, particularly their consumption of deer truffles, which accumulate cesium over time.

Why does wild boar meat still show high radioactivity levels despite the Chernobyl disaster occurring decades ago?

The high radioactivity levels in wild boar meat are due to the combined effects of cesium-137 from the Chernobyl disaster and cesium from 1960s nuclear tests. While other game meats have shown a decrease in radioactivity over time, the unique feeding habits of wild boars, especially their consumption of deer truffles that slowly absorb cesium from the soil, have led to sustained high radioactivity levels in their meat.

How did scientists determine the source of the radioactivity in wild boar meat?

Scientists from TU Wien and the Leibniz University of Hannover conducted detailed studies using mass spectrometric methods to measure not only the amount but also the origin of the radioactivity. By analyzing the ratio of cesium isotopes, particularly cesium-137 and cesium-135, they were able to distinguish between radioactivity from Chernobyl and that from 1960s nuclear weapons tests, leading to the discovery of the latter’s significant contribution.

More about Radioactive Wild Boars

  • Chernobyl Nuclear Disaster
  • Radioactive Contamination in Wildlife
  • Cesium and Radioactivity
  • Environmental Impacts of Nuclear Testing
  • Wild Boar Dietary Habits
  • Scientific Analysis of Radioactivity
  • TU Wien Research on Radioactivity
  • Leibniz University of Hannover Studies
  • Radioactive Isotopes in Ecosystems
  • Wildlife Management and Radioactivity

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Mike Johnson December 2, 2023 - 8:47 am

I think there’s a typo in the part about deer truffles, or maybe I just don’t understand the science? It’s a bit confusing.

John Smith December 2, 2023 - 10:10 am

Really interesting article, didn’t know that wild boar meat was still affected by Chernobyl, and the 60’s nuclear tests, it’s kinda scary to think about.

Sarah Davis December 2, 2023 - 7:27 pm

Great read! It’s amazing how long-lasting the impact of human actions can be on nature. Makes you think twice about the environment.

Emma Brown December 2, 2023 - 9:21 pm

wow, the way cesium affects the environment and food chains is complex. The article does a good job explaining it, but it’s still a lot to take in.

Alex Lee December 2, 2023 - 11:48 pm

could’ve used more on the impact on wildlife besides boars, feels a bit narrow in scope but still a good piece overall.


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