A box of dried porcini mushrooms weighing 31 kilograms failed inspection at Domodedovo Airport. Devices detected radiation exceeding the natural background by more than ten times. Inside was Russian-made produce, and the inspection revealed cesium-137 — a radioactive isotope.

According to the Federal Customs Service, the box was checked in as luggage by a passenger who was going to fly to Uzbekistan. The radiation control system signaled, after which customs officers opened the cargo and checked the contents with a portable radiometer-spectrometer.

The information was forwarded to Rospotrebnadzor. The agency recognized the batch as radioactive waste subject to disposal.

How mushrooms could accumulate radioactive substances

Professional mushroom picker Dmitry Tikhomirov explains that mycelium absorbs substances from the environment. If the soil is contaminated with cesium-137, it can accumulate in mushrooms as well.

The expert suggests that the raw materials could have been collected in an area affected by radioactive contamination in the past. As one of the possible reasons, he names the consequences of the Chernobyl accident and mentions the Bryansk region. However, the collection site of this batch has not been officially established, so this version cannot be considered confirmed.

When drying, mushrooms lose water, and the accumulated substances remain. Therefore, their concentration per unit mass of the product can increase. Tikhomirov notes that checking raw materials for radiation is important even before mushrooms reach the shelves.