In the morning of 13 May, an explosion took place in the Khmelnytskyi Oblast in western Ukraine. The Russian attack was aimed at critical infrastructure. Narratives appeared on the Internet that a “depleted uranium” storage facility was hit and destroyed. Increased measurements of the bismuth isotope from 15 May were presented as evidence of the alleged radioactive cloud approaching Poland. In the article we explain that the radiation situation in the country is normal and where the fluctuations in the level of bismuth in the atmosphere come from.
Manipulations regarding bismuth
Piotr Panasiuk, known for spreading Russian propaganda, posted a tweet in which he included measurements of the radiation levels of some isotopes. The graph shows a spike in bismuth levels. This information, in the context of his previous posts, was to suggest the threat of a radioactive cloud. A similar narrative has been viewed almost 200,000 times.
The news about a possible radioactive threat was denied by the National Atomic Energy Agency, which reassured that the radiation situation in the country is normal. The statement also reads that the temporary increase in the value of ionizing radiation is a natural effect of rainfall.
Bismuth and rainfall
According to UMCS scientists, the increase in radiation levels observed on 15 May, 2023 is a natural phenomenon caused by rainfall. Bismuth, specifically its isotope bismuth-214, is formed by the decay of radon rising from the ground. Radon, an odourless and colourless noble gas, is formed in the decay chain of uranium-238. This isotope is a component of depleted uranium, which is used e.g., in the arms industry. Uranium is a natural component of soil and gangue, a waste rock of commonly used bituminous coal. The figure below shows the entire uranium-radium decay chain.
Marie Curie-Skłodowska University in Lublin monitors radioactivity in the air. We checked the measurements from the beginning of May. The graph of the radiation levels of characteristic isotopes was compared with the rainfall chart. The correlation is also very visible in previous days.
For comparison, we checked the levels in September 2022, and at the beginning of the month measurements indicated a higher level of bismuth-214 than in May 2023. Here, too, this relationship can be observed.
Doses of nuclear radiation
According to prof. Paweł Moskal, the effect of nuclear radiation-induced poisoning depends on the capacity of the particular immune system. Therefore, it is impossible to determine unequivocally a universal lethal dose. Instead, a dose is determined, after which half of the population dies within 30 days. In the case of humans, it is about 3.5 Sv. The Sievert is a unit expressing the amount of radiation energy absorbed by living tissue in relation to the biological effects of radiation. As the graph below shows, the radiation level in Lublin measured on 15 May was 0.66 µSv/h, so it was significantly below the anomalous limit and over 5 million times lower than the life-threatening dose. To sum up, the discussed level of radioactivity in May in Lublin is of natural origin and does not pose a threat to us.
Pro-Russian propaganda is once again trying to evoke anxiety in our country. This time, to support its thesis about the false threat of a radioactive cloud, it used a natural physical phenomenon. The increased level of the isotope bismuth-214 is the result of rainfall and does not indicate harmful radiation after the explosion in Ukraine.
dr Urszula Kaźmierczak: Wyznaczanie promieniowania radonu
prof. Paweł Moskal: Dawki promieniowania jądrowego