Ambient gamma dose rate measurements near fire-affected areas, available at http://www.srp.ecocentre.kiev.ua/MEDO-PS/index.php?lang=ENG, do not reveal abnormal values.
However, it should be noted that these measurement devices are only capable of detecting major radiological accidents. “Such a probe is installed at the French Embassy in Kiev and is part of the IRSN’s Téléray network deployed in France,” the institute said.
“The radioactivity released into the atmosphere by the fires was therefore not high enough to be detected by these devices. On the other hand, much more sensitive measurements have been carried out by various Ukrainian scientific bodies that have published airborne 137Cs activities from aerosol samplings.”
In Kiev, the highest airborne 137Cs activities in the air were recorded from April 9 to 11, 2020: 470 micro becquerel/cubic meter (µBq/m3) from April 9 to 10 ; 700 µBq/m3 from April 10 to 11. A value of 1,200 µBq/m3 during the night of April 4 to 5, 2020 has also been reported by the Scientific State and Technical Center for Nuclear and Radiological Safety in Ukraine but has not been confirmed.
These values are significantly higher than the values usually measured for cesium 137 in the air in Kiev and show evidence of the passage of contaminated air masses. However, they remain moderate and have no health consequences, IRSN said.
In the Chernobyl exclusion zone, much greater air contamination is observed due to the closeness to the measuring devices in the burned area. The institute carried out an estimation of the dosimetric impact of the fires according to different scenarios. The results showed that for a fire-fighter who worked for 100 hours in the exclusion zone in an environment with an airborne activity level of 1 Bq/m3 (or 1,000,000 µBq/m3 ) of cesium 137 and 1 Bq/m3 of strontium 90 (a major assumption compared to the measurements carried out in the area), the calculated dose corresponding to the inhalation of radioactive fire smokes is approximately 13 micro sievert (µSv).
It should be noted that this dose is much lower than that which results from the external exposure of fire-fighters by the radiation emitted by the contaminated soil and which, in the exclusion zone, is very often greater than 1 µSv/h. This is consistent with estimates made by Ukrainian scientists which indicate that the doses received by fire-fighters as a result of smoke inhalation are in the range of 1% of the dose induced from the exposure to ground radiation.
For a resident of Kiev exposed for a few days to radioactivity levels comparable to those measured by Ukrainian organizations in Kiev, the inhalation dose received by an adult is less than 1 nano sievert (1 nSv = 0.001 µSv) which is extremely weak.
In the following video, you may see scary colours (like redish), but actually the amounts refer to μBq/m^3, which is 1000000 lower than 1 Bq/m^3.
Source : watchers.news