Consequences of Chernobyl accident in Europe

Full text: Among nuclides emitted from the destroyed Chernobyl reactor only radioiodine and radiocesium were of serious health concern. The amount of iodine-131 released in this catastrophe was about 180 times lower than during the total release of this nuclide from 77 nuclear weapon tests performed in remote areas in the record year of 1962, and the release of cesium-137 was only five times lower. However, the bulk of Chernobyl emission was confined in time to only twelve days, and its geographical dispersion was much smaller and closer to populated areas than that of nuclear tests debris. Only a small part of cesium-137 and cesium-134 from the Chernobyl reactor reached the Southern Hemisphere, via stratospheric transport routes. Therefore, radiation doses received by the population from the Chernobyl radionuclides was in the affected areas higher than from the nuclear tests fallout. In part of Europe the doses received by children in the thyroid gland from iodine-131 radiation were high enough to expect an increase in thyroid cancers. In the contaminated regions of Belarus, Ukraine and Russia the estimated thyroid doses in children could reach up to several thousand mSv. In a group of >100,000 persons evacuated during the first few weeks, the average thyroid dose in children under 3 years of age was about 1000 mSv, and in adults about 70 mSv. Between 1986 and 1995 about 700 thyroid cancers in children were reported from Belarus, Ukraine and Russia, most of which may be attributed to Chernobyl radiation. About 95% of these cancers are believed to be curable. The whole body dose from cloud passage, ground deposition and intake of cesium-137 and of other radionuclides was much smaller than thyroid doses, and do not pose a real risk to the population. The average lifetime (70 years) whole body doses in the most contaminated regions of Belarus ranged between 88 and 160 mSv, in Ukraine 84 and 120 mSv and in Russia 78 to 130 mSv. The average doses to 800,000 'liquidators' ranged between 170 mSv in 1986 and 15 mSv in 1989. Among the >100,000 evacuees the average whole body dose prior to evacuation was 15 mSv. The average lifetime Chernobyl whole body doses in European countries outside the former Soviet Union range from 0.006 mSv in Portugal to 2.4 mSv in Bulgaria. In the Northern Hemisphere the average Chernobyl lifetime dose is 0.14 mSv, i.e. about 0.08% of the natural dose. The average global whole body dose of natural radiation during 70 years is about 170 mSv, and 700 mSv in typically high background areas. Epidemiological studies from Hiroshima and Nagasaki suggest that no increase in cancer mortality should be expected at a single whole body dose (in addition to natural background radiation) of <200 mSv, delivered during a fraction of a second. Doses of about 200 mSv accumulated over tens of years of exposure would be even less effective. Ten years after the Chernobyl catastrophe the total radiation death toll is 31 - 38 persons, among them 3 persons were the members of the public. The total expected number of thyroid cancer deaths is about 500. In Poland, a country closest to Chernobyl outside the former Soviet Union, during two days, starting on the second day after arrival of radioactive cloud, 18.5 million persons were administered a prophylactic dose of stable iodine in form of 'Lugol solution', to block the uptake of radioiodine by the thyroid. This caused a thyroid dose reduction by a factor of up to 5, without any intra-thyroid side effects. Economic loses related to necessary and unnecessary remedial measures are estimated to reach in Belarus between 1986 and 2015 US$ 191.7 billion, of which US$ 86.32 billion are costs of financial and other compensation ('privileges') for peoples living at contaminated regions. It is estimated that in Ukraine in regions where 'Chernobyl radiation dose' is less than 1 mSv/year about 1.73 million persons receives the 'privileges'. Psychosomatic consequences of radiophobia induced by mass-media and policy of authorities in the contaminated regions are also discussed