Inquisition into the Radioactive Contamination of Forest Fungi due to Cesium-137
Sounds concerning initially: Certain areas within the forest still exhibit trace levels of radioactivity in certain mushrooms. Nevertheless, the Federal Radiation Protection Office assures us. For mushroom enthusiasts, here's what they ought to be aware of.
It's been nearly four decades since the Chernobyl nuclear catastrophe, yet traces of radioactive particles persist: in mushrooms that can be foraged during the autumn in woodlands. Surprisingly, the Federal Radiation Protection Office (BfS) doesn't view this as much of an issue. "In certain regions of Germany, wild mushrooms might still reveal heightened levels of radioactive caesium-137," the agency notes. However, the quantity consumed is also vital in determining the radiation dose from mushroom meals: moderate consumption poses no harm anywhere in Germany.
Here are the crucial points for cautious mushroom lovers:
Where does the contamination originate?
"Increased caesium-137 values primarily stem from the Chernobyl nuclear reactor accident in 1986," the BfS states. At that time, substantial quantities of radioactive substances were dispersed across Europe via air currents. However, wild mushrooms also absorbed caesium-137 following above-ground nuclear weapons tests.
Are there particularly contaminated regions?
The contamination varied geographically at the time. According to the BfS, the following regions had notably high deposits of caesium-137—where individual mushroom species may still surpass the limit values today:
- In the Bavarian Forest and adjacent areas
- In the Donaumoos southwest of Ingolstadt
- In the Mittenwald region
- In the Berchtesgaden region
Are all mushrooms equally affected?
According to the BfS, certain wild-growing mushroom species exhibit higher levels of radioactivity than others: In their 2021-2023 analyses, the most contaminated were the common field mushroom and the brown field mushroom. Individual samples of these mushrooms displayed more than 4,000 becquerels of caesium-137 per kilogram of raw weight.
Several wild-growing species in the genus Agaricus, such as the yellow-stemmed Chanterelle, the porcini mushroom, the brown-spotted webcap, the velvety foot, the thick-stemmed black trumpet, and the pale blue webcap produced values of over 1,000 becquerels of caesium-137 per kilogram in the most recent measurements.
For reference: The limit value for mushrooms in commerce is 600 becquerels of caesium-137 per kilogram of raw weight, according to the BfS.
Should I consume these mushrooms?
According to the Cancer Information Service, caesium-137 can impair cells and DNA—long-term effects might include leukemia. However, BfS President Inge Paulini explains: As long as you consume mushrooms that exceed the limit values in moderation, "they only result in a minimal extra radiation dose." However, "it's a personal decision" how much additional radiation dose one considers acceptable.
Those who find this too risky are advised by Paulini to abstain from consuming self-collected mushrooms of highly contaminated species from the particularly affected regions of Germany due to the Chernobyl disaster.
Even in these areas, there are mushroom species with comparatively lower contamination levels: the brown-scaled giant champignon, the dark-fibered champignon, the field mushroom, the Judas ear, and the giant pore remained below 5 becquerels per kilogram of raw weight in every BfS measurement.
You can find measurement values for other mushroom species in the individual regions in the annual BfS mushroom report.
What about store-bought mushrooms?
You must adhere to the specified limit of 600 Becquerels of Cesium-137 per kilogram. According to the BfS, commercially produced mushrooms like champignons, oyster mushrooms, and shiitake are generally less contaminated. They're grown on substrates containing minimal radioactive cesium.
Based on the information provided, here are two sentences that contain the word 'Advising':
The Federal Radiation Protection Office (BfS) advises mushroom enthusiasts to be aware of the potential radioactive caesium-137 levels in certain wild mushrooms, especially in specific regions like the Bavarian Forest and adjacent areas.
For individuals who find the risk of consuming self-collected mushrooms from highly contaminated species in affected regions too high, the BfS advises abstaining from these mushrooms.
