RSH Data & Documents

"Low Level
Radiation Health
Effects: Compiling
the Data"

Revision 2
March 30, 1999
by Radiation, Science, and
Health, Inc.,
Edited by J. Muckerheide

1.2.5.2.1
Chernobyl/Urals

"Eleven years that passed since the Chernobyl catastrophe are more than enough for realistic assessment of its early and late health effects."

"The late effects were expected to occur among three categories of persons: 1) 106 persons who survived acute radiation sickness after receiving very high doses of radiation, 2) several million inhabitants of contaminated regions in Ukraine, Belarus and Russia who received doses comparable to their average natural lifetime dose, and 3) 600,000 to 800,000 accident recovery workers ('liquidators') who received similar doses in the 30-km zone around the Chernobyl reactor (Table 1). Estimates of imaginary post-Chernobyl cancers were also made for hundreds of millions of people in the Northern Hemisphere who received from Chernobyl fallout tiny fractions of the natural radiation dose. For example, for United States where Chernobyl increased the natural radiation background dose by 0.004% an exact number of 30 cancer death was predicted over the next 50 years, and 28,000 for the Northern Hemisphere, where radiation close was increased by 0.3% (Goldman et al 1987). By far the largest group are people in three post-soviet countries with real psychosomatic health effects, caused not by radiation but by policy and actions of authorities, and by mass media.

Table 1

"At the moment of the accident, there were about 470 people on the site of the Chernobyl Nuclear Power Plant: 1) personnel on-duty (about 201 persons): 2) construction workers (about 250 persons): and 3) firemen on-duty and guards (about 20 persons). Among them, 134 (about one third) were diagnosed with acute radiation sickness (ARS) (Ilyin 1995). These ARC patients received high radiation doses, and 28 of them died in the first four months following the accident (Table 1). Deaths in 26 of these patients were associated with radiation skin lesions involving over 50% of the total body surface area. Two more patients died during the first days as a result of severe thermal burns and mechanical trauma. One further death was thought to have been due to coronary thrombosis. Thus, the total number of deaths due to early effects of the Chernobyl accident amounts to 31."

"Acute radiation sickness patients

"Over the last ten years 14 persons have died of the 106 ARS patients who survived the acute phase. These later deaths (due to car accident, lung gangrene, coronary heart disease, tuberculosis, thigh sarcoma etc.) are rather not attributable to radiation exposure (Wagemaker et al 1996). However, follow-up of these patients needs to be assured for the forthcoming two or three decades, to distinguish between any radiation related diseases of these patients and confounding factors intrinsic to the population."

"Inhabitants of contaminated regions in former USSR and elsewhere

"The late effects among the inhabitants of contaminated regions can be estimated from epidemiological observations and on the basis of radiation doses received by them from the deposited radionuclides. The greatest contamination covered several regions in Belarus, Ukraine and Russia, often in the form of 'islands', tens and hundreds of kilometers away from Chernobyl. Contamination with 137 Cs above 185 kBq/m2 covered 1,530 km2 in Belarus, 8,130 km2 in Russia, and 4,630 km2 in the Ukraine (Anonymous, 1996 A). About 1.06 million people lived in these regions. Even at the regions contaminated above 555 kBq/m2, only a small number of persons (about 670) received radiation doses per whole body higher than 200 mSv in the years 1986-1989 (Table 2). Below the dose of 200 mSv epidemiological studies in Hiroshima and Nagasaki did not find increased incidence of cancers (UNSCEAR 1994). However, in the former Soviet Union a mass relocation of people from the areas of still lower 137Cs contamination (>37 kBq/m2) was carried out (Anonymous, 1996 B). 'Islands' of high contamination also covered regions remote from the former USSR. For example, in the Oppland region of Norway contamination with 137Cs reached 104 kBq/m2 (Backe et al 1986), and in the Gavle region in Sweden about 200 kBq/m2 (Snihs 1996). Such islands, where radiocesium contamination reached up to 120 kBq/m2 were found in Greece, Romania, Switzerland, Austria, and Southern Germany."

"The average deposition density of Chernobyl 137Cs in Europe outside the former USSR ranged from 20 Bq/m2 in Portugal to 23,000 Bq/m2 in Austria. In Poland the average 137Cs deposit from Chernobyl of 5000 Bq/m2 was similar as that from the nuclear weapon tests (UNSCEAR 1988). These deposition densities of 137Cs were usually measured in a 10 cm thick layer of soil, and they can be compared with the average content of natural radionuclides (40K, 14 members of uranium-238 family, and 10 members of thorium-228 family) in the same volume of soil or rock (Table 2). Even in highly contaminated areas in the former USSR the content of 137Cs is lower than the higher range of content of natural radionuclides in soil. In Europe outside the former USSR the soil content of 137Cs from Chernobyl is hundreds to thousands times lower than the content of natural radionuclides.

(Insert Table 2)

"The average whole body radiation doses received in the period 1986-1995 in the most contaminated regions of the former USSR (6 to 60 mSv) were by a factor of 3 lower than the average lifetime dose which the population of the Earth receives from natural radiation sources (Table 3). However, in regions with a high natural radiation background where, like in India, people have been living for 30 generations, the typical average whole body doses are more than 20 times higher than in contaminated parts of the Ukraine, Belarus and Russia from which the people were evacuated. No adverse health effects were found in these high natural radiation regions. To the contrary, in some of them people were found to live longer and have fewer cancers (see e.g. Jaworowski 1997)."

(Insert Table 3)

"In the highly contaminated regions of the former USSR neither a study carried out four years after accident by a group of 200 international experts (ICP 1991) nor the later studies (Cardis et al 1996) found an increase in leukemia or solid cancers, except for thyroid cancers (see below).

"The majority of people living in contaminated regions received radiation doses ranging between 5 and 100 mSv. Epidemiological studies of survivors of nuclear attacks on Hiroshima and Nagasaki show that at such doses one may expect not an increase but rather a decrease of leukemia incidences. Numerous epidemiological studies of people working in the Canadian, American and British nuclear industry, of patients irradiated during x-ray diagnostics, and people irradiated in villages in the Eastern Urals after a thermal explosion in a Soviet military facility, indicate that at this dose range the incidence of solid cancers is lower than in the non-irradiated population (see review in Jaworowski 1997)."

"Liquidators

"The follow-up of the recovery operation workers in Belarus, Ukraine and Russia is much more active than that of the general population of these three countries. The intensity of screening may greatly influence the observed incidence of diseases. Among the 'liquidators' the general incidence of diseases (980 per 1000 men of working age per year) is about 25% lower than among the general population of Russia (1,300/1000), and no increase in the rate of leukemia was observed (Tukov and Dzakoeva 1993). According to Legato et al. (1993) the number of all neoplasms in 'liquidators' from Ukraine has not increased during 7 years after the accident. Among the 'liquidators' from Belarus the incidence of cancers was in men 22%, and in women 9% lower than in the general population (Okeanov et al 1996). Well-organized studies, based on comparison with adequate control groups have shown identical morbidity and mortality for 'liquidators' and other population groups (Logachev et al 1993: Nilova et al 1995; Okladnikova et al 1992)."

THYROID CANCERS IN CHILDREN

"…on the one hand [there is] a great uncertainty of estimates of the thyroid radiation doses received. On the other hand, epidemiological studies of patients receiving radioiodine (131I) for therapeutic and diagnostic reasons demonstrated a lack of increase in thyroid cancers after doses higher than those received by inhabitants of contaminated regions.

"It is well known that thyroid cancers appear six to nine years after external irradiation with x-rays of gamma rays. No childhood study has found as excess of thyroid cancer within five years of exposure, even after high-dose radiation therapy (Tucker et al 1991; Ron et al 1995). But in the former USSR the rise in thyroid cancer incidence had already been registered four years, and even one year after the accident (Prisyazhniuk et al 1991; Kazakov 1992; Remennik et al 1996). … Maximum thyroid doses in children from the former USSR were not higher than in the Swedish patients. In Belarus in only about 300 children they reached above 10,000 mSv (Ilyin et al 1990; Zvonova & Balonov 1993; Buldakov 1993). The average thyroid doses in various contaminated regions ranged from 10-3300 mSv.

"The total number of thyroid cancers in children registered until 1995 in contaminated regions…is about 650. Curability of thyroid cancers is above 90% (Reiners et al 1996). Until now three children have died (OECD 1996)."

"That occult cancers and changes in diagnostics may dramatically influence the number of registered thyroid cancers, indicate the results of a screening study of people in the United States who had received radiation treatment of head and neck. As may be seen in Figure 4, during the most active period of screening in 1974-1979 the incidence rate of malignant and all thyroid nodules was greater 2-fold than before 1974. This increase is of the order of that seen in Belarus (Ron et al 1992). The increased number of thyroid cancers registered in the former USSR may be an effect of intensification and improvement of diagnostics, rather than a real effect of radiation."

NON-RADIATION EFFECTS

"Nearly five million people in the former Soviet Union have been affected by severe psychological stress, leading to psychosomatic diseases (Filyushkin 1996). This real harm outweighs any hypothetical radiation risk due to low level radiation in contaminated areas. The psychological stress was inflicted on inhabitants of contaminated areas by convincing them that it was fatally dangerous to live there, even though the radiation level in these areas was lower than the natural radiation in many countries where people live since time immemorial, without any sign of health detriment. The mass media in the former Soviet Union and elsewhere, the political decisions of the Soviet and post-Soviet governments, and the system of radiation standards based on linear, non-threshold hypothesis developed by ICRP, are responsible for evoking mass stress effects. A large segment of the medical profession, among which the knowledge on radiation effects was formed by mass media rather than university curricula, played also an important role. … Many doctors interpreted the symptoms of common diseases as the effects of Chernobyl irradiation. This was common in Poland and in other European countries outside the USSR, where due to incompetent medical advice probably several hundred thousand abortions of 'wished' pregnancies were carried out (Trichopolous et al 1987; Spinelli and Osborn 1991; Czeizel 1994). In the countries of the former Soviet Union this reached a catastrophic scale, where even a sore tooth or dryness of mouth was regarded as a Chernobyl effect (ICP 1991). Even an imaginary, non-existing new disease was tailor-made there for post-accident situation: a 'vegetative distonia', was supposed to be caused by Chernobyl radiation. This diagnosis, with no definitive diagnostic tests, was assigned by parents and doctors to account for childhood complaints and accepted by adults as an explanation for vague symptoms. At any one time; up to 1000 children were hospitalized in Kiev alone, often for weeks, for treatment of this non-existent 'disease' (OECD 1996).

"During the past ten years mass media and politicians of the former USSR has tried their best to convince the people in contaminated regions of Belarus, Ukraine and Russia that Chernobyl radiation endangers their health and life. ... An aggravation of this problem was caused by official declaring of millions of people to belong to the category of 'Chernobyl victims'. This was done by implementation of laws on financial compensation for these people, called by the locals a 'coffin subsidy'. In the Ukraine alone, this category was assigned to about 3 million people and the costs involved reach 1/6 of the state budget (OECD 1996). In the impoverished Belarus these subsidies will reach 86 billion US dollars until 2015 (Rolerich 1996). Each act of signing a receipt for a monthly subsidy is for millions of receivers a confirmation that they really are the 'victims of Chernobyl'. For who would pay them just for nothing, and not for a real health detriment which they must already suffer, or for being in a situation of radiation risk, which sooner or later will cause such detriment. Nobody tells them that their small radiation doses (averaging 6-60 mSv in various regions), or even a bit higher doses to 'liquidators' (170 mSv in 1986) are below the level of 200 rnSv at which an increase of cancer incidence was detected in Hiroshima and Nagasaki, or that in these Japanese cities irradiated survivors of the nuclear attack live longer than non irradiated ones, and that no increase of congenital diseases was detected in their offspring.

"The second important cause of non-radiation health effects was legislation (currently in force) prescribing the relocation of 850,000 people, and the actual relocation of about 400,000 inhabitants of contaminated regions (Ilyin 1995; Anonymous 1996A; Filyushkin 1996)."

"Relocation was a drastic measure, the declared aim of which was the protection of health, and specifically protection against DNA damages in somatic cells (which could induce cancers) or in genetic cells (which could increase congenital diseases). Irradiation of the human body with a dose of 1 mSv per year, from which relocation was started, causes in each cell about 0.2 damage of DNA per year, or 14 damages per 70 years. These radiation-induced DNA damages are of the same types as spontaneous damages caused by other factors, only the proportion of particular types differs. The number of spontaneous DNA damages, due to thermodynamic processes and action of free radicals (such as OH, peroxides, and reactive oxygen species) is 70 million in one cell per year (Billen 1990). This indicates how powerful are the mechanisms of DNA repair and other mechanisms of homeostasis, which in the flood of physico chemical changes keep the integrity of organisms during an individual life and over thousands of generations. This also shows how absurd was the decision on mass relocation in the former USSR. The aim was to defend the population against about 14 DNA damages per cell in 70 years, whereas at the same time due to natural causes there will be 4.9 billion DNA damages per cell. The probability that these 14 DNA damages will cause a cancer and not one of the 4.9 billion spontaneous damages is 1 in 350 millions, which practically means: zero.

"According to the linear, no-threshold hypothesis the limits of 350 mSv and 150 mSv accepted for relocation, were supposed to spare the population from a 1.75% and 0.75% increase in cancer incidence, respectively. These limits were in agreement with the ICRP recommendations for protection of the public in radiation accidents, published two years before the Chernobyl catastrophe (ICRP 1984). In this document ICRP recommended relocation in the intermediate phase of the accident, when the individual whole body radiation dose may reach 50 mSv in the first year, which in the case of Chernobyl radiation corresponds to a lifetime dose of about 150 mSv. The still lower limit of 70 mSv was based on the ICRP dose limit of 1 mSv per year for the entire population (Filyushkin 1996). These limits are by a factor of 4 to 40 lower than the natural lifetime doses in many inhabited regions of the world (e.g. 1500 mSv in Norway, 2000 mSv in India, 3000 mSv in Iran). In the case of the Chernobyl accident, implementation of ICRP recommendations led to disastrous practical consequences of unnecessary relocation of several hundred thousand people, and of inducing an aggravated form of radiophobia with psychosomatic consequences in millions of people in the former Soviet Union. I doubt, however, that the ICRP would be willing to accept responsibility for these practical consequences of its 'easy chair' speculative recommendations."

CONCLUSIONS

"The fatalities of the Chernobyl accident caused by ionizing radiation, are 28 victims who succumbed to acute radiation sickness. Three more persons died during the first few weeks due to non-radiation factors of the catastrophe. Thus, the total of the early victims amounts to 31 persons. Over the next ten years 3 children died due to thyroid cancers, but it is not certain whether these three fatal cancers, and 679 other thyroid cancers registered until the end of 1995, were caused by Chernobyl radiation. Meticulous studies of Swedish patients in which no increase of thyroid cancers was found after average radiation doses from radioiodine higher than from Chernobyl fallout in the former USSR, indicate that these cancers apparently have not been caused by Chernobyl accident.

"The average whole body radiation doses from Chernobyl fallout to populations of contaminated regions of the former Soviet Union were slightly smaller than the average global natural lifetime dose, and by a factor of 4 to 40 smaller than in regions with high natural radioactivity. Even smaller doses were received in other countries. Therefore, it should not be surprising that no increase in the incidence of solid cancers, leukemias or hereditary diseases that might be caused by the whole body doses of Chernobyl radiation was detected in the populations of the former Soviet Union and elsewhere.

"Psychosomatic consequences, on the other hand, appeared in great number of inhabitants of contaminated regions in Belarus, Ukraine and Russia. The cause of these latter consequences was not radiation or any other physical factor, but hysterical radiophobia, induced by mass media and improper policy of authorities, which was based on linear no-threshold hypothesis and ICRP recommendations.

"Apart from enormous economic losses in the former Soviet Union and in other countries, most of which were due to unwise policy (Becker 1996), in terms of early and late fatalities the Chernobyl catastrophe should be regarded as a minor one, in comparison with other industrial accidents of the 20th century (Table 8)...A striking feature in Table 8 is that the three most famous disasters which are permanently imprinted in common public memory: Windscale, Three Mile Island and Chernobyl, are those with the lowest death toll. One of the causes of this imbalance is the linear no-threshold hypothesis of harm from radiation, which was also the most important factor responsible for initiating the Chernobyl fear and for its current perpetuation. Falsification of this hypothesis seems to be an issue for the coming decade, and may possibly help in forming a more rational approach to radiation protection of the public, and realistic estimates of risks from nuclear industry.

Table 8

"Chernobyl was the worst possible catastrophe of a badly constructed and recklessly operated nuclear power reactor, with a complete core melt-down, followed by a free dispersion of radionuclides in the atmosphere. Nothing worse could have happened. It resulted in a comparatively minute death toll, amounting to about half of those killed weekly in weekend traffic accidents in Poland."