| Home | E-Submission | Sitemap | Contact Us
top_img

Schmitz-Feuerhake, Busby, and Pflugbeil: Genetic radiation risks: a neglected topic in the low dose debate

Abstract

Objectives

To investigate the accuracy and scientific validity of the current very low risk factor for hereditary diseases in humans following exposures to ionizing radiation adopted by the United Nations Scientific Committee on the Effects of Atomic Radiation and the International Commission on Radiological Protection. The value is based on experiments on mice due to reportedly absent effects in the Japanese atomic bomb (Abomb) survivors.

Methods

To review the published evidence for heritable effects after ionising radiation exposures particularly, but not restricted to, populations exposed to contamination from the Chernobyl accident and from atmospheric nuclear test fallout. To make a compilation of findings about early deaths, congenital malformations, Down’s syndrome, cancer and other genetic effects observed in humans after the exposure of the parents. To also examine more closely the evidence from the Japanese A-bomb epidemiology and discuss its scientific validity.

Results

Nearly all types of hereditary defects were found at doses as low as one to 10 mSv. We discuss the clash between the current risk model and these observations on the basis of biological mechanism and assumptions about linear relationships between dose and effect in neonatal and foetal epidemiology. The evidence supports a dose response relationship which is non-linear and is either biphasic or supralinear (hogs-back) and largely either saturates or falls above 10 mSv.

Conclusions

We conclude that the current risk model for heritable effects of radiation is unsafe. The dose response relationship is non-linear with the greatest effects at the lowest doses. Using Chernobyl data we derive an excess relative risk for all malformations of 1.0 per 10 mSv cumulative dose. The safety of the Japanese A-bomb epidemiology is argued to be both scientifically and philosophically questionable owing to errors in the choice of control groups, omission of internal exposure effects and assumptions about linear dose response.

Introduction

The most serious effects of ionizing radiation–hereditary defects in the descendants of exposed parents–had been already detected in the 1920s by Herman Joseph Muller. He exposed fruit flies–drosophila–to X-rays and found malformations and other disorders in the following generations. He concluded from his investigations that low dose exposure, and therefore even natural background radiation, is mutagenic and there is no harmless dose range for heritable effects or for cancer induction. His work was honoured by the Nobel Prize for medicine in 1946. In the 1950s Muller warned about the effects on the human genetic pool caused by the production of low level radioactive contamination from atmospheric tests [1].
The International Commission on Radiological Protection (ICRP) recently decreased its risk estimate for heritable damage in 2007 [2,3]. Its Detriment Adjusted Nominal Risk Coefficient for radiation heritable effects in an exposed population was reduced from the previous 1990 value of 1.3% Sv-1 to 0.2% Sv-1 a greater than 6-fold reduction. The ICRP approach is based on a linear relation between dose and end-point, measured as heritable disease at or before birth. Evidence and arguments which we will present suggest that this linear assumption is invalid and that the ICRP value is unsafe when applied to the chronic low dose internal exposure range.
The belief that heritable consequences of radiation were negligible followed from studies of the Japanese survivors of the atomic bomb (A-bomb) explosions in Hiroshima and Nagasaki in 1945. The American-Japanese Institute in Hiroshima, Atomic Bomb Casualty Commission (ABCC), did not apparently find mutations in the descendants of the survivors. Therefore the ICRP derive its current risk figure from experiments in mice. The result corresponds to the evaluation by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR committee) [4].
We will show that the current model for genetic effects of exposure is unsound and we present a more realistic one based on data. We will begin by pointing to some serious problems with the ABCC studies of genetic effects in the A-bomb survivors. These may be classed under four Error Types.
Type 1. The dose response problem. For genetic damage, increasing dose will not linearly increase effects since at high doses there will be sterility or fetal loss [5].
Type 2. The external/internal problem. The dose of interest is the energy delivered to the germ cells and their precursors. This may be much higher for internal radionuclides with affinity for DNA (strontium-90 [Sr-90], barium-140, uranium) [6].
Type 3. The philosophical method problem. If data is interpreted though a particular scientific model, evidence which cannot fit the model will be ignored, dismissed or invisible [7,8].
Type 4. Bias in the analysis of or presentation of data from the ABCC results. There have been a number of serious criticisms of the ABCC and later studies of cancer effects. The genetic studies were criticised by De Bellefeuille [9] who demonstrated the existence of significant genetic effects including sex-ratio and malformations which had been “lost” through the choice of analysis. However, De Bellefeuille’s observations were ignored by the risk agencies. The issue will be returned to in the discussion section.
Together these raise major doubts over the belief, expressed in ICRP103, Appendix B.2.01 [2], that “Radiation induced heritable disease has not been demonstrated in human populations.”
Effects in populations exposed to Chernobyl fallout are excluded by the official committees, which claim that doses are too low to generate statistically observable increases (the philosophical method problem: Error Type 3). This, however, is certainly wrong, because we know from many studies of chromosome aberrations, either that the doses calculated by UNSCEAR are much too low or that there is an enhanced radiobiological effectiveness (RBE) in the type of internal exposures or chronic delivery received by the Chernobyl groups. In other words, the biological or genetic damage from unit internal dose e.g., from a radioactive atom bound to DNA is far greater than for the same dose delivered externally. This is Error Type 2: internal/external problem. The doses upon which the ICRP risks are based, either from humans or mice, are external doses. There are significant issues regarding the equivalence for causing genetic damage of internal and external dose calculations [6]. Internal exposure to uranium by inhalation, for example, has been associated with significantly high genotoxicity resulting in anomalously high excess levels of chromosome damage and birth defects in a number of different groups [10]. Uranium binds to DNA, a fact that has been known since the 1960s [11-13]. Other group II calcium mimics and DNA seekers include the nuclide Sr-90 which causes significant genetic effects [14-17]. All epidemiological studies of radiation and health which define risk factors have been subject of this Error Type 2: external/internal problem, and have generally also defined risk in terms of cumulative integrated equivalent dose, and so real effects have been ignored or dismissed, the Error Type 3: philosophical problem.

Findings in Children Born After the Chernobyl Accident and in Kazakhstan

We previously published findings about fetal deaths, perinatal mortality and congenital malformations (CM) after Chernobyl [18]. Table 1 shows results for CM after Chernobyl. These appeared not only in the area of the exploded reactor but also in Turkey, Bulgaria, Croatia, and Germany. Our criteria for inclusion of this evidence was originally to present only observations which disagreed with the current ICRP/UNSCEAR paradigm but following questions by a reviewer we include discussion of one of the few studies with contemporary data which claims to have shown that there were no measurable heritable effects [19].

The EUROCAT Europe-wide Study

The study of Dolk and Nichols [19] is widely cited as evidence for no effect. The authors examined Down’s syndrome, neural tube defects (NTD), microcephaly, hydrocephaly, anopthalmos and congenital cataract in 16 EUROCAT registers. There were 231401 births in the areas in 1986. The 16 registries were divided into three groups of high (200 to 800 μSv), medium (97 to 190 μSv) and low (29 to 55 μSv). Three comparison cohort periods were defined as E (conception May 1986), T (conception May 1986 to April 1987 contains E), and C (control: conception May 1987 to April 1989). Authors concluded “no evidence of a generalised detectable increase in the prevalence of congenital anomalies in the first month or first year following Chernobyl.” But the choice of the cohort periods for a study of “heritable effects” is interesting. On the basis of whole body monitoring results, genetic damage to the germ cells from internal exposures will have continued well into the control period C and damage will have been cumulative [44]. We have reanalysed their data for combined NTD hydrocephaly, microcephaly and anopthalmia in all their exposure groups using their periods. A test of T vs. C cohorts showed a significant effect with odds ratio (OR) of 1.20 (95% confidence interval [CI], 1.02 to 1.4; p=0.014). This was apparent in the test of E vs. C though the numbers were smaller. However, there was no increasing monotonic relation between assumed “dose” category and effect and this clearly influenced the authors’ conclusions. This is the common response to the finding of high risks at low doses and represents a good example of the Error Type 1 referred to above. It appears that the results actually show an increased risk if we combine all the exposure levels.

Chernobyl Effects in Belarus

Belarus received most contamination from Chernobyl. A central registry for CM existed from 1979 and rates of CM before and after the Chernobyl accident could thus be compared. A number of studies are listed in Table 1. Comparison of legal abortuses in 1982 to 1985 and 1987 to 1994 showed combined CM increases of 81%, 49%, and 43% in regions of high (>555 kBq/m2), medium (>37 kBq/m2), and low (<37 kBq/m2) contamination, the effect being significant at the 0.05 level in all three [22]. The genetic origin is confirmed in those anomalies which are combined with a recognized mutation that is not present in either of the parents [18].
A study [23] confirmed the CM excess in the Strict Registration of Malformations System finding 86% increase in 1987 to 1996 vs. 1982 to 1985 (high contamination) and 59% (control regions) (p<0.05). The same authors reported significant excess chromosome aberrations of dicentric and centric rings rates of 0.39±0.09% (n=91) in Gomel and Mogilev (>555 kBq/m2) compared with a control region of Minsk, Grodno and Novopolotsk (<37 kBq/m2) (n=118; CM=0.09±0.04) [23].
To 2004 there was no decrease in these rates [45]. The authors think these effects are genetically induced because it is not plausible that doses in pregnant females rose in the period of decreasing environmental contamination and decreasing food contamination after the accident. A Belarussian-Israeli group [46] found the following increased polygenetic disease rates in children of Chernobyl- exposed parents: hematological diseases (6-fold), endocrine diseases (2-fold), diseases of digestive organs (1.7-fold).
A 1994 study compared Gomel (high exposure) with Vitebsk (presumed low exposure) for mortality in children zero to four finding absolute CM rates of 4.1% vs. 3%, respectively [24]. Savchenko [25] writing for the United Nations reported frequency of CM in regions of Gomel between 1982 to 1985 and 1987 to 1989 ranging from 170% in Dobrush to 680% in Chechersk.
Petrova et al. [27] compared two high and two low contaminated regions of Belarus for a number of indicators of pregnancy outcome and child health. For CM, before and after Chernobyl increases for all CM were: Gomel 150%>Mogilev 130%>Brest 120%>Vitebsk 110%, the rank of their contamination levels. Kulakov et al. [26] examined 688 pregnancies and 7000 births in Chechersky (Gomel, Belarus) and Polessky (Kiev, Ukraine). Sharp reductions in birth rates in both regions after Chernobyl were ascribed partly to abortions. High perinatal mortality was ascribed partly to congenital malformations. Incidence increased by a factor of two following the accident for congenital heart disease, esophageal atresia, anencephaly, hydrocephaly and multiple malformations. Total number of neonatal disorders increased in Polessky (Ukraine) from 1983 to 1985 to 1986 to 1990 from 6.81 to 21.32 (313%) and in Chechersky from 5.15 to 10.49 [26].

Chernobyl Effects in Ukraine

The studies by Wertelecki and colleagues [29,30] were valuable for quantifying the effects. The Pripyat region of Ukraine on the border of Belarus was significantly contaminated. Populations are dependent on local produce. Internal contamination was quantified for two groups, a high and lower dose group by whole body monitoring for caesium-137 (Cs-137). In addition, local produce was analysed for both Cs-137 and the DNA seeking Sr-90. The Sr-90/Cs-137 ratio was between 0.5 and two, so Sr-90 (with its DNA affinity and anomalous RBE) represented a significant internal exposure.

Other Reports of Chernobyl Effects on Birth Defects; Soviet Nuclear Test Site

Down´s syndrome as a certain genetic effect increased in several contaminated European countries [18,48]. An example is shown in Figure 1. In West Berlin, which was a kind of closed island at that time, the geneticist Sperling registered a sharp and significant increase in cases exactly nine months after the accident, also in Belarus [49]. UNSCEAR [4,20] dismissed these findings (and similar reports from Scotland and Sweden) on the basis that the doses were “below background.” The EUROCAT combined registry study [19] did not find an increase in Down’s syndrome, neither in the authors’ analysis nor in our reanalysis. Other evidence is presented in Table 1 of increased CM rates after Chernobyl in Germany, Turkey, Croatia and Bulgaria [21,32-37,50].
Congenital effects were found near the former Soviet nuclear test site in Kazakhstan near Semipalatinsk. Sviatova et al. [51] studied CM in three generations of inhabitants, investigating births between 1967 and 1997. They found significantly increased rates of CM combined, including Down’s syndrome, microcephaly and multiple malformations in the same individual.

Hereditary Effects in Children of Exposed Mothers

If a population is exposed, genetic effects will occur in the gonads of mothers as well as of fathers. A German investigation of occupationally exposed females showed a 3.2-fold significant increase in congenital abnormalities, including malformations, in offspring [52]. The authors interpret the effect as generated in utero but do not prove such a connection. In our opinion, this appears to be improbable given the short sensitive phase in pregnancy and the ban on pregnant females working in high risk environments.
The findings confirm early results in the Department of Medical Genetics of Montreal Children’s Hospital where the genetic effects of diagnostic X-rays were investigated [53]. The author observed the offspring of mothers who had been treated in childhood for congenital hip dysplasia since 1925 and were X-rayed for several times in the pelvic region. The ovarian dose was estimated to lie between 60 mSv to 200 mSv. In 201 living births of these females there were 15 individuals with severe malformations and other congenital distortions or Down’s syndrome and 11 cases with other abnormalities (all congenital abnormalities 12.9%) while the control group showed less than half of this rate. The latter was chosen from a large group of descendants where the parents were unexposed siblings of the study group.
Taken together with other evidence from sex-ratio (discussed below) these studies indicate that hereditary effects exist in the children of exposed mothers.

Findings in the Descendants of Occupationally Exposed Men Including Nuclear Test Veterans

Congenital Malformations

Studies in children of exposed men where the mothers were not exposed will show definite hereditary effects. A compilation of results for CM in offspring of exposed fathers is given in Table 2.
The anomalies seen in the descendants of Chernobyl liquidators (Nos. 5-7) also indicate unexpectedly high radiation sensitivity.
Three studies of nuclear test veterans have shown large increases in congenital effects in children and one study has found similar levels of congenital conditions in the grandchildren (Nos. 8-10). The British carried out nuclear weapon tests and activities in Australia (Maralinga) and Christmas Island in the Pacific between 1952 and 1967. More than 20000 young national servicemen and other military personnel were stationed at the test sites. The sites were contaminated with fission fallout and nanoparticles of uranium and plutonium from the weapons, tritium and carbon-14. Urquhart [61] analysed data in children from 1147 veteran families. Two hundred and thirty-three out of them had illnesses or defects (cancer, malformations, mental retardation) that could have a genetic origin: one in five families. They registered a 7:1 rate of abnormal children conceived before the tests vs. those conceived after the tests.
Two further studies of the offspring of a group of veterans have been published. Roff [62] carried out a questionnaire study of members of the British Nuclear Test Veteran Association (BNTVA) and reported excess rates of cardiovascular disorders, spina bifida, hydrocephalus and hip deformities. Busby and de Messieres [63] examined a different sample of the BNTVA, employed controls and compared with the European EUROCAT rates. Based on 605 veteran children and 749 grandchildren compared with 311 control children and 408 control grandchildren there were significant excess levels of miscarriages, stillbirths, infant mortality and congenital illnesses in the veterans’ children relative both to control children and expected numbers. There were 105 miscarriages in veteran’s wives compared with 18 in controls (OR, 2.75; 95% CI, 1.56 to 4.91; p<0.001). There were 16 stillbirths; three in controls (OR, 2.70; 95% CI, 0.73 to 11.72; p=0.13). Perinatal mortality OR was 4.3 (95% CI, 1.22 to 17.9; p=0.01) on 25 deaths in veteran children. Fifty-seven veteran children had congenital conditions vs. three control children (OR, 9.77; 95% CI, 2.92 to 39.3; p<0.001) these rates being also about eight times those expected on the basis of UK EUROCAT data for 1980 to 2000. For grandchildren similar levels of congenital illness were reported with 46 veteran grandchildren compared with three controls (OR, 8.35; 95% CI, 2.48 to 33.8; p<0.001).

Cancer and Leukemia

In 1984, an exceptionally high level of leukaemia cases in children and juveniles was reported in Seascale, near the nuclear reprocessing plant in Sellafield in Cumbria, UK. The authors explained this as a hereditary effect, because the fathers of the patients had worked in the plant [64]. The authorities argued that the doses were too low. The effect, however, had been described in principle already in experimental studies [65], and also after X-ray diagnostic exposures (Table 3). A significant number of other child leukemia and cancer studies have been carried out and are listed in Table 3.
The research of Hicks et al. [66] concerned exposed servicemen (Table 3). McKinney et al. [67] found a 3.2-fold increase in leukaemia and lymphomas in children of occupationally exposed men in three British regions in a case-control study.

Sex-ratio and X-linked Lethal Factors

Normally, it is not possible to study how many inseminated oocytes (zygotes) will be aborted after irradiation of the gonadal cells in humans. But it is observed that males who were exposed have fewer daughters than sons i.e., the male/female sex-ratio increases with dose.
Gene mutations may be responsible for the death of the zygote and will also occur in the sex chromosomes where they will predominantly affect the greater X-chromosome which can only be transmitted to a daughter. A dominant lethal factor will then lead to the death of the female zygote. Recessive lethal factors in the X-chromosome are much more frequent than dominant ones [74]. They affect only female births.
An impressive result was obtained in workers of the British nuclear fuel reprocessing plant at Sellafield in West Cumbria [75]. The county sex-ratio was 1055 boys/1000 girls, the normal value. For the children of fathers employed at Sellafield the ratio was 1094. For those with recorded doses greater than 10 mSv in the 90 days preconception period it was 1396, significant at the p<0.01 level. A similar effect was detected in cardiologists, who undertook interventional angiographic procedures involving X-ray exposures [76].
Scherb and Voigt studied different groups of inhabitants in a variety of countries after the Chernobyl accident for hereditary effects and found radiation-induced foetal deaths and early mortality, Down’s syndrome and alterations of the birth sex-ratio. They examined nuclear tests above ground which affected US inhabitants, Chernobyl emissions in Europe, and those living near German and Swiss nuclear plants. Results showed significant reduction in the female birth rate in all these [77,78].
The ABCC studies overall involve all the types of research error listed in the introduction, which we believe is the explanation for the failure to see excess heritable damage. The main problem was choice of controls. The sex-ratio studies were abandoned due to seemingly anomalous effects. De Bellefeuille [9] re-examined the issue in 1961 and found that results were biased by employing sex-ratios of children of parents who had both been exposed. Any effects, being in opposite directions, would therefore cancel out; his re-analysis based on children with only one exposed parent showed a clear effect in the expected direction. Padmanabhan [79] recently re-examined the issue using the original controls (abandoned by ABCC). Using the two not in city (NIC) groups Padmanabhan showed significant sex-ratio effects in the expected directions.
Sex-ratio is a very relevant parameter. It shows that genetic alterations are induced in the germ cells of males by very low doses, and it proves to be a sensitive indicator for exposures of the population.

Atmospheric Weapons test Fallout

The most significant global incident in terms of human exposure has been the atmospheric nuclear testing fallout which peaked between 1959 and 1963. It was this testing which worried Muller [1]. The tests increased the rates of neonatal and infant mortality in the US and the UK [80,81]. An interesting insight comes from a Canadian study of CM during the fallout period. le Vann [82] was concerned to examine the link between congenital malformation and the use of the drug thalidomide. He found that in Alberta there was no relation between the use of thalidomide and congenital birth outcomes but noted a strong association with precipitation; areas with high radioactive fallout had high levels of birth defects. Whilst we are not alleging that thalidomide does not have teratogenic effects, since many females in the le Vann study who never took any drugs gave birth to the typical “thalidomide spectrum” babies it seems that exposure to the fallout may have, as Muller [1] feared, have caused an effect. Ignoring this and the infant mortality findings involved a Error Type 3.

Genetic vs. Genomic, Mendelian vs. In Utero

We have not distinguished between Mendelian genetic effects involving the transfer of specific gene mutations to the offspring and effects consequent upon the operation of genomic instability, whereby the offspring inherit a tendency to apparently increase rates of all mutation above the normal rate for that population [83]. For the purposes of the arguments relating to radiation risk of harmful heritable conditions in the first generation such a discussion is unnecessary but needs to be revisited if multi-generational effects are being discussed. The question of germ cell damage in parents vs. in utero damage to development, though important, seems to us to be beside the point. All these CM effects are caused by mutation of DNA whether in the parental germ cells and precursors or from implantation to birth. Our aim is to assess the genetic risk based on observations. However, from the sex-ratio results it would seem that parental exposure is a dominant cause of radiation induced CM.

How Is It That the ICRP Risk Coefficient Is Wrong?

A reviewer asked us to address this question and to provide a brief account of biological mechanism. We begin with mechanism. The ICRP risk model is based on two big ideas: absorbeddose, which is average energy per unit mass of tissue, and the linear no threshold (LNT) response. For internal exposure to substances like Sr-90 and uranium, which both have high affinity for DNA, the concept of dose is meaningless [loc.cit. 6,10]. For CM as an outcome, it is also clear that the LNT model is unsustainable [5], because as the “dose” is increased from zero there are many blocks to the successful journey from germ cell to infant, the CM end point. Biological plausibility would predict an increase in damage and thus CM at very low dose, followed by a drop in CM due to failure to implant, early miscarriage, abortion. This would result in a saturation or “hogs-back” dose response in the lowest dose region. Only the survivors would make it to be registered as CM. The dose response would look like that in Figure 2 where A is the initial outcome and B is where the foetus dies or there is no implantation. The region C would relate to in utero effects later in gestation. There would be a fall in birth rate associated with region B and C; there usually is. You can see this effect most clearly in the EUROCAT studies where relative risk rises and then falls as dose increases [19]. It is perfectly clear in many other studies. It is clear in in analysis of infant leukemia after Chernobyl in 5 countries shown in Figure 3 [84] and the study of cleft palate in Bavaria [38,39] analysed by Korblein [40].

What Is the Correct Risk Coefficient?

The Chernobyl studies presented in Table 1 may be used to obtain an approximate risk factor for all CM in those exposed to fission spectrum radionuclides as assessed by Cs-137 area contamination. We can employ the data from Wertelecki et al. [30] on internal contamination to assess doses from Cs-137 and Sr- 90. The excess relative risk (ERR) for all CM follows a “hogsback” shaped response and is about 0.5 per mSv at 1 mSv saturating at between 0.1 to 0.2 per mSv at 10 mSv based on cumulative dose as assessed by ICRP models using Cs-137 area contamination as a basis of calculations. This means that the background rate will double or treble up to 10 mSv exposure and thereafter flatten out or fall. But it also results in a 50% excess risk at doses as low as 1 mSv. This ERR and dose response model accommodates all the observational data from Chernobyl and also elsewhere. We must make it clear that this model is for mixed internal and external exposure to fission product contamination doses as employed by UN agencies and may not necessarily apply to pure external exposures (e.g., X-rays, gamma- rays). However, it should be noted that Stewart’s finding of a 40% excess risk of childhood leukemia after a 10 mSv obstetric X-ray dose [71] is comparable with what is found at these higher doses in this review.

Conclusion

Genetically induced malformations, cancers, and numerous other health effects in the children of populations who were exposed to low doses of ionizing radiation have been unequivocally demonstrated in scientific investigations. Using data from Chernobyl effects we find a new ERR for CM of 0.5 per mSv at 1 mSv falling to 0.1 per mSv at 10 mSv exposure and thereafter remaining roughly constant. This is for mixed fission products as defined though external exposure to Cs-137. Results show that current radiation risk models fail to predict or explain the many observations and should be abandoned. Further research and analysis of previous data is suggested, but prior assumptions of linear dose response, assumptions that internal exposures can be modelled using external risk factors, that chronic and acute exposures give comparable risks and finally dependence on interpretations of the high dose ABCC studies are all seen to be unsafe procedures.

ACKNOWLEDGEMENTS

We are grateful to Marvin Resnikoff and Rick Haaker for running the Microshield program for dose rates over contaminated areas.

CONFLICT OF INTEREST

The authors have no conflicts of interest associated with material presented in this paper.

References

1. Muller HJ. Radiation damage to the genetic material. Am Sci 1950;38(1):33-59.
pmid
2. International Commission on Radiological Protection. The 2007 recommendations of the International Commission on Radiological Protection. 2007. [cited 2016 Jan 28]. Available from: http://www.icrp.org/publication.asp?id=ICRP%20Publication%20103.

3. International Commission on Radiological Protection. 1990 Recommendations of the International Commission on Radiological Protection. 1991. [cited 2016 Jan 28]. Available from: http://www.icrp.org/publication.asp?id=icrp%20publication%2060.

4. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). UNSCEAR 2001 report: hereditary effects of radiation. 1991. [cited 2016 Jan 28]. Available from: http://www.unscear.org/unscear/en/publications/2001.html.

5. Doll R. Hazards of the first nine months: an epidemiologist’s nightmare. J Ir Med Assoc 1973;66(5):117-126.
crossref pmid
6. Busby C. Aspects of DNA damage from internal radionuclides. 2013. [cited 2016 Jan 28]. Available from: http://www.intechopen.com/books/new-research-directions-in-dna-repair/aspects-ofdna-damage-from-internal-radionuclides.
crossref
7. Platt JR. Strong inference: certain systematic methods of scientific thinking may produce much more rapid progress than others. Science 1964;146(3642):347-353.
crossref pmid
8. Feyerabend P. Against method. 4th ed. London: Verso; 2010. p. 13-48.

9. De Bellefeuille P. Genetic hazards of radiation to man. I. Acta Radiol 1961;56: 65-80.
crossref
10. Busby C. Uranium epidemiology. Jacobs J Epidemiol Prev Med 2015;1(2):009.

11. Huxley HE, Zubay G. Preferential staining of nucleic acid-containing structures for electron microscopy. J Biophys Biochem Cytol 1961;11: 273-296.
crossref pmid pmc
12. Constantinescu DG, Hatieganu E. Metachromasia through uranyl ions: a procedure for identifying the nucleic acids and the nucleotides. Anal Biochem 1974;62(2):584-587.
crossref pmid
13. Nielsen PE, Hiort C, Sonnichsen SH, Buchardt O, Dahl O, Norden B. DNA binding and photocleavage by uranyl(VI)(UO22+) salts. J Am Chem Soc 1992;114(13):4967-4975.
crossref
14. Luning KG, Frolen H, Nelson A, Ronnback C. Genetic effects of strontium-90 injected into male mice. Nature 1963;197: 304-305.
crossref pmid
15. Ehrenberg L, Eriksson G. The dose dependence of mutation rates in the rad range, in the light of experiments with higher plants. Acta Radiol Diagn (Stockh) 1966;Suppl 254: 73-78.

16. Stokke T, Oftedal P, Pappas A. Effects of small doses of radioactive strontium on the rat bone marrow. Acta Radiol Ther Phys Biol 1968;7(5):321-329.
crossref pmid
17. Smirnova EI, Lyaginskaya AM. Effects of small doses of radioactive strontium on the rat bone marrow. In: Moskalev YI, Idz Y, editors. Radioactive isotopes and the body. Moscow: Izdatel’stvo Meditsina; 1969. p. 348 (Russian).

18. Busby C, Lengfelder E, Pflugbeil S, Schmitz-Feuerhake I. The evidence of radiation effects in embryos and fetuses exposed to Chernobyl fallout and the question of dose response. Med Confl Surviv 2009;25(1):20-40.
crossref pmid
19. Dolk H, Nichols R. Evaluation of the impact of Chernobyl on the prevalence of congenital anomalies in 16 regions of Europe. Int J Epidemiol 1999;228(5):941-948.
crossref
20. United Nations Scientific Committee on the Effects of Atomic Radiation. UNSCEAR 2006 report vol. I: effects of ionizing radiation. [cited 2016 Jan 28]. Available from: http://www.unscear.org/unscear/en/publications/2006_1.html.

21. Hoffmann W. Fallout from the Chernobyl nuclear disaster and congenital malformations in Europe. Arch Environ Health 2001;56(6):478-484.
crossref pmid
22. Lazjuk GI, Nikolaev DL, Novikova IV. Changes in registered congenital anomalies in the Republic of Belarus after the Chernobyl accident. Stem Cells 1997;2: 255-260.
crossref
23. Feshchenko SP, Schröder HC, Müller WE, Lazjuk GI. Congenital malformations among newborns and developmental abnormalities among human embryos in Belarus after Chernobyl accident. Cell Mol Biol (Noisy-le-grand) 2002;48(4):423-426.
pmid
24. Bogdanovich IP. Comparative analysis of the death rate of children, aged 0-5, in 1994 in radiocontaminated and conventionally clean areas of Belarus. Medicobiological effects and the ways of overcoming the Chernobyl accident consequence. Minsk-Vitebsk: Ministry of Emergency and Chernobyl Problems of Belarus and Academy of Sciences of Belarus; 1997. p. 4 (Russian).

25. Savchenko VK. The ecology of the Chernobyl catastrophe: scientific outlines of an International Programme of Collaborative Research. Paris: United Nations Educational Scientific and Organisation; 1995. p. 83.

26. Kulakov VI, Sokur TN, Volobuev AI, Tzibulskaya IS, Malisheva VA, Zikin BI, et al. Female reproductive function in areas affected by radiation after the Chernobyl power station accident. Environ Health Perspect 1993;2: 117-123.
crossref
27. Petrova A, Gnedko T, Maistrova I, Zafranskaya M, Dainiak N. Morbidity in a large cohort study of children born to mothers exposed to radiation from Chernobyl. Stem Cells 1997;2: 141-150.
crossref
28. Shidlovskii PR. General morbidity of the population in districts of the Brest region. Zdravoohranenie Belorussii (Minsk) 1992;1: 8-11 (Russian).

29. Wertelecki W. Malformations in a Chernobyl-impacted region. Pediatrics 2010;125(4):e836-e843.
crossref
30. Wertelecki W, Yevtushok L, Zymak-Zakutnia N, Wang B, Sosyniuk Z, Lapchenko S, et al. Blastopathies and microcephaly in a Chernobyl- impacted region of Ukraine. Congenit Anom (Kyoto) 2014;54(3):125-149.
crossref pmid pmc
31. Godlevsky I, Nasvit O. Dynamics of health status of residents in the Lugyny district after the accident of the ChNPS. In: Imanaka T, editor. Research activities about the radiological consequences of the Chernobyl NPS accident and social activities to assist the sufferers by the accident. Osaka: Kyoto University Research Reactor Institute; 1998. p. 149-156.

32. Akar N, Ata Y, Aytekin AF. Neural tube defects and Chernobyl? Paediatr Perinat Epidemiol 1989;3(1):102-103.
crossref pmid
33. Caglayan S, Kayhan B, Menteşoğlu S, Aksit S. Changing incidence of neural tube defects in Aegean Turkey. Paediatr Perinat Epidemiol 1989;3(1):62-65.
crossref pmid
34. Güvenc H, Uslu MA, Güvenc M, Ozekici U, Kocabay K, Bektaş S. Changing trend of neural tube defects in eastern Turkey. J Epidemiol Community Health 1993;47(1):40-41.
crossref pmid pmc
35. Mocan H, Bozkaya H, Mocan MZ, Furtun EM. Changing incidence of anencephaly in the eastern Black Sea region of Turkey and Chernobyl. Paediatr Perinat Epidemiol 1990;4(3):264-268.
crossref pmid
36. Moumdjiev N, Nedkova V, Christova V, Kostova S. Influence of the Chernobyl reactor accident on the child health in the region of Pleven, Bulgaria. International Pediatric Association. Excerpts from the 20th International Congress of Pediatrics; 1992 Sep 5-10; Rio de Janeiro, Brazil. Vevey: Nestlé Nutrition Services. 1992, p.57.

37. Kruslin B, Jukić S, Kos M, Simić G, Cviko A. Congenital anomalies of the central nervous system at autopsy in Croatia in the period before and after the Chernobyl accident. Acta Med Croatica 1998;52(2):103-107.
pmid
38. Zieglowski V, Hemprich A. Facial cleft birth rate in former East Germany before and after the reactor accident in Chernobyl. Mund Kiefer Gesichtschir 1999;3(4):195-199 (German).
crossref pmid
39. Scherb H, Weigelt E. Cleft lip and cleft palate birth rate in Bavaria before and after the Chernobyl nuclear power plant accident. Mund Kiefer Gesichtschir 2004;8(2):106-110 (German).
crossref pmid
40. Korblein A. Abnormalities in Bavaria after Chernobyl. Strahlentelex 2004;417: 4-6 (German).

41. Government of Berlin West; Section of Health and Social Affairs. Annual health report. Berlin: Government of Berlin West; 1987. (German).

42. Lotz B, Haerting J, Schulze E. Changes in fetal and childhood autopsies in the region of Jena after the Chernobyl accident. 1996. [cited 2016 Jan 28]. Available from: http://www.meb.uni-bonn.de/gmds/abstracts/0095e.html (German).

43. Eckerman KF, Ryman JC. Federal guidance report 12: external exposure to radionuclides in air, water and soil. 1993. [cited 2016 Feb 20]. Available from: https://crpk.ornl.gov/documents/fgr12.pdf.

44. Busby C, Cato MS. Increases in leukemia in infants in Wales and Scotland following Chernobyl: evidence for errors in statutory risk estimates. Energy Environ 2000;11(2):127-139.
crossref
45. Yablokov AV, Nesterenko VB, Nesterenko AV. Chernobyl– consequences of the Catastrophe for people and the environment. 2009. [cited 2016 Feb 20]. Available from: http://www.strahlentelex.de/Yablokov_Chernobyl_book.pdf.

46. Lomat L, Galburt G, Quastel MR, Polyakov S, Okeanov A, Rozin S. Incidence of childhood disease in Belarus associated with the Chernobyl accident. Environ Health Perspect 1997;6: 1529-1532.
crossref
47. Scherb H, Sperling K. Today’s lessons from the Chernobyl accident. Naturwiss Rundsch 2011;64(5):229-239 (German).

48. Sperling K, Neitzel H, Scherb H. Evidence for an increase in trisomy 21 (Down syndrome) in Europe after the Chernobyl reactor accident. Genet Epidemiol 2012;36(1):48-55.
crossref pmid
49. Zatsepin IO, Verger P, Gagniere B, Khmel RD; Belarus Institute for Hereditary Diseases. Cluster of Down’s syndrome cases registered in January 1987 in Republic of Belarus as a possible effect of the Chernobyl accident. Int J Radiat Med 2004;6(1-4):57-71.

50. Akar N. Further notes on neural tube defects and Chernobyl. Pediatr Perinatal Epidemiol 1994;8: 456-457.

51. Sviatova GS, Abil’dinova GZh, Berezina GM. Frequency, dynamics, and structure of congenital malformations in populations under longterm exposure to ionizing radiation. Genetika 2001;37(12):1696-1704 (Russian).
pmid
52. Wiesel A, Spix C, Mergenthaler A, Queisser-Luft A. Maternal occupational exposure to ionizing radiation and birth defects. Radiat Environ Biophys 2011;50(2):325-328.
crossref pmid
53. Cox DW. An investigation of possible genetic damage in the offspring of women receiving multiple diagnostic pelvic X rays. Am J Hum Genet 1964;16: 214-230.
pmid pmc
54. Macht SH, Lawrence PS. National survey of congenital malformations resulting from exposure to roentgen radiation. Am J Roentgenol Radium Ther Nucl Med 1955;73(3):442-466.
pmid
55. Sever LE, Gilbert ES, Hessol NA, McIntyre JM. A case-control study of congenital malformations and occupational exposure to low-level ionizing radiation. Am J Epidemiol 1988;127(2):226-242.
pmid
56. Parker L, Pearce MS, Dickinson HO, Aitkin M, Craft AW. Stillbirths among offspring of male radiation workers at Sellafield nuclear reprocessing plant. Lancet 1999;354(9188):1407-1414.
crossref
57. Shakhatreh FM. Reproductive health of male radiographers. Saudi Med J 2001;22(2):150-152.
pmid
58. Tsyb AF, Souchkevitch GN, Lyasko LI, Artamonova YZ, Navolokin VV, Raykina LG. General characterization of health in first-generation offspring born to liquidators of the Chernobyl NPP accident consequences. Int J Radiat Med 2004.

59. Matveenko EG, Borovykova MP, Davydow GA. Physical characteristics and primary morbidity in liquidator´s children. In: Yablokov AV, Busby C, editors. Chernobyl 20 years after. Aberystwyth: Green Audit Books; 2006. p. 176-179.

60. Liaginskaia AM, Tukov AR, Osipov VA, Ermalitskiĭ AP, Prokhorova ON. Congenital malformations among offspring of the liquidators of the consequences from Chernobyl accident. Radiats Biol Radioecol 2009;49(6):694-702 (Russian).
pmid
61. Urquhart J. Radiation exposure and subsequent health history of veterans and their children. New Evaluation of Radiation Risk, International Conference of the Society for Radiation Protection. Bremen: Gesellschaft fur Strahlenschutz; 1992. p. 209-216 (German).

62. Roff SR. Mortality and morbidity of members of the British Nuclear Tests Veterans Association and the New Zealand Nuclear Tests Veterans Association and their families. Med Confl Surviv 1999;15 Supple 1: i-ix, 1-51.

63. Busby C, de Messieres ME. Miscarriages and congenital conditions in offspring of veterans of the British Nuclear Atmospheric Test Programme. Epidemiology (Sunnyvale) 2014;4: 172.

64. Gardner MJ, Snee MP, Hall AJ, Powell CA, Downes S, Terrell JD. Results of case-control study of leukaemia and lymphoma among young people near Sellafield nuclear plant in West Cumbria. BMJ 1990;300(6722):423-429.
crossref
65. Nomura T. Parental exposure to x rays and chemicals induces heritable tumours and anomalies in mice. Nature 1982;296(5857):575-577.
crossref
66. Hicks N, Zack M, Caldwell GG, Fernbach DJ, Falletta JM. Childhood cancer and occupational radiation exposure in parents. Cancer 1984;53(8):1637-1643.
crossref pmid
67. McKinney PA, Alexander FE, Cartwright RA, Parker L. Parental occupations of children with leukaemia in west Cumbria, north Humberside, and Gateshead. BMJ 1991;302(6778):681-687.
crossref
68. Graham S, Levin ML, Lilienfeld AM, Schuman LM, Gibson R, Dowd JE, et al. Preconception, intrauterine, and postnatal irradiation as related to leukemia. Natl Cancer Inst Monogr 1966;19: 347-371.
pmid
69. Shu XO, Gao YT, Brinton LA, Linet MS, Tu JT, Zheng W, et al. A population-based case-control study of childhood leukemia in Shanghai. Cancer 1988;62(3):635-644.
crossref pmid
70. Shu XO, Reaman GH, Lampkin B, Sather HN, Pendergrass TW, Robison LL. Association of paternal diagnostic X-ray exposure with risk of infant leukemia. Investigators of the Childrens Cancer Group. Cancer Epidemiol Biomarkers Prev 1994;3(8):645-653.
pmid
71. Stewart A, Webb J, Hewitt D. A survey of childhood malignancies. Br Med J 1958;1(5086):1495-1508.
crossref pmid pmc
72. Natarajan N, Bross ID. Preconception radiation and leukemia. J Med 1973;4(5):276-281.
pmid
73. Shiono PH, Chung CS, Myrianthopoulos NC. Preconception radiation, intrauterine diagnostic radiation, and childhood neoplasia. J Natl Cancer Inst 1980;65(4):681-686.
pmid
74. Vogel F, Rohrborn G, Schleiermeyer E. Radiation genetics in mammals. Stuttgart: Verlag; 1969. (German).

75. Dickinson HO, Parker L, Binks K, Wakeford R, Smith J. The sex ratio of children in relation to paternal preconceptional radiation dose: a study in Cumbria, northern England. J Epidemiol Community Health 1996;50(6):645-652.
crossref pmid pmc
76. Choi JW, Mehrotra P, Macdonald LA, Klein LW, Linsky NM, Smith AM, et al. Sex proportion of offspring and exposure to radiation in male invasive cardiologists. Proc (Bayl Univ Med Cent) 2007;20(3):231-234.
pmid pmc
77. Scherb H, Voigt K. Trends in the human sex odds at birth in Europe and the Chernobyl Nuclear Power Plant accident. Reprod Toxicol 2007;23(4):593-599.
crossref pmid
78. Scherb H, Voigt K. The human sex odds at birth after the atmospheric atomic bomb tests, after Chernobyl, and in the vicinity of nuclear facilities. Environ Sci Pollut Res Int 2011;18(5):697-707.
crossref pmid
79. Padmanabhan VT. Sex ratio in A-bomb survivors. Evidence of radiation induced X-linked lethal mutations. In: Busby C, Busby J, Rietuma D, de Messieres M, editors. Fukushima and health: what to expect. Proceedings of the 3rd International Conference for the European Committee on Radiation Risk. 2009 May 5-6; Lesvos, Greece. Aberystwyth: Green Audit: 2012, p.273-304.

80. Sternglass EJ. Environmental radiation and human health. In: In: LeCam LM, Neyman J, Scott EL, editors. Proceedings of the Sixth Berkeley Symposium on Mathematical Statistics and Probability. 1971 Jul 19-22; Berkeley, CA, USA. Berkeley: University of Calififornia Press: 1971, p.145-221.

81. Whyte RK. First day neonatal mortality since 1935: re-examination of the Cross hypothesis. BMJ 1992;304(6823):343-346.
crossref
82. le Vann LJ. Congenital abnormalities in children born in Alberta during 1961: a survey and a hypothesis. Can Med Assoc J 1963;89(3):120-126.
pmid pmc
83. Baverstock K, Belyakov OV. Some important questions connected with non-targeted effects. Mutat Res 2010.
crossref
84. Busby CC. Very low dose fetal exposure to Chernobyl contamination resulted in increases in infant leukemia in Europe and raises questions about current radiation risk models. Int J Environ Res Public Health 2009;6(12):3105-3114.
crossref pmid pmc

Figure 1.
Down’s syndrome before and after the Chernobyl accident (A) West Berlin and (B) Belarus. From Scherb H, et al. Naturwiss Rundsch 2011;64(5):229-239, with permission from Stuttgart [47].
eht-31-e2016001f1.tif
Figure 2.
Regions of interest in a theoretically predicted dose response relation (see text and ECRR 2010). Exactly this dose response is seen in infant leukemia rates after Chernobyl in Greece, Germany (three dose regions) Wales, Scotland and Belarus [84]. From Busby C. Aspects of DNA damage from internal radionuclides; 2013 [6]. aQ is the background cancer rate in the population at background radiation levels, the position where the graph starts.
eht-31-e2016001f2.tif
Figure 3.
Dose response for infant leukemia in the countries examined in meta-analysis of five reports in Busby 2009 [84] (UK data from Childhood Cancer Research Group Oxford). Effect is fractional excess relative risk, and dose is given by UK National Radiological Protection Board in mSv.
eht-31-e2016001f3.tif
Table 1.
Increase of congenital malformations after exposure by the Chernobyl accident
Country and region Study Details Estimated dosesa 1 yr (mSv) adult Reference
Europe wide
 UNSCEAR Review Concludes: “conflicting results"; “no changes in birth defects could be related to ionizing radiation" mainly on basis of a lack of biological gradient Nationwide 1 yr doses: 0.2-10 mSv UNSCEAR 2000 [4];
Mainly based on external Cs-137 UNSCEAR 2006 [20]
Review by Little Review Largely as above
 EUROCAT study 16 regions of Europe 16 EUROCAT registries: Down’s syndrome, NTD, hydrocephaly, microcephaly, arhinecephaly, an/micropthalmia, congenital cataract 3 Cohort periods; 231401 births in 1986; authors concluded no effect apparent; but examination of data presented shows excess risk for all but Down’s syndrome in both assumed exposed cohorts relative to assumed non-exposed cohort; for 1987 vs. 1988/1989 OR 1.2 (95% Cl, 1.02-1.4),p<0.05; see text Higha: 0.2-0.7 mSv, mediuma: 0.1-0.2 mSv, lowa: 0.03-0.06 mSv Dolket al. 1999 [19]
External Cs-137
 Review by Hoffmann Down’s syndrome, NTD, cleft palate, other malformations Review of studies from Turkey, Bulgaria, Croatia, Germany, Belarus, Finland, Norway, EUROCAT registries; guestions established risk coefficients and linear dose response on basis of observations 0.1-0.5 mSvb Hoffmann 2001 [21]
Belarus
National Genetic Anencephaly, spina bifida, cleft lip and/or palate, polydactyly, limb reduction defects, esophageal atresia, anorectal atresia, Down’s syndrome, multiple malformations 1. Pathologies of legal medical abortuses Based on Cs-137 area contamination 1 yr external dosea,c is: 6.7 mSvat555 kBq/m2 0.44 mSv at 37 kBq/m2 Lazjuk et al. 1997 [22]
 Monitoring Registry Total congenital malformation increase 1987-1994 vs. 1982-1985 in three regions defined by Cs-137 contamination; >555 kBq/m2=81%, n=151- 381, p<0.05 Internal Cs-137 annual adult dose on basis of Polissia highest contamination area
Wertelecki is 1 mSv Cs-137 and 2 mSv Sr-90 (ICRP 72 ingestion)
>37 kBq/m2=49%, n=899-2180, p<0.05 UN estimates 2 mSv first year dose for all Belarus
Control <37 kBq/m2=43%; n=255-649, p<0.05
Excluded teratogenic effects; cannot exclude selection bias as analysis of unreportable abortuses not possible; Down’s syndrome increase in lower dose regions not high dose region
2. Congenital malformation in neonates
Whole of Belarus; increase in frequency of congenital malformation from 12.5/1000 in 1985 to 17.7 /1000 in 1994; increasing risks stabilized by abortions at upper level due to State intervention program
National Genetic 1. Chromosome aberrations 1. 1986-1988 mean Dicentric and Ring chromosome anomaly (CA) As above Feshchenko et al. 2002 [23]
 Monitoring Registry Contaminated region (Gomel and Mogilev) n=91; CA=0.39+-0.09%; (>555 kBq/m2) Total annual effective dosea,c is less than 10 mSv
2. Strict Registration of Malformations System Control region (Minsk, Grodno, Novopolotsk) n=118; CA = 0.09+-0.04
2. Human embryos aborted foetus Dose to ovaries is the same as effective dose
Same list of malformations as a Lazjuk; increase rate 1982-1985 to 1987-1996 is 86% in contaminated regions and 59% in control regions, p<0.05, n=617 in high dose region, 1104 in control region
Highly exposed region of Gomel Congenital malformations 1. Mortality in children 0-4 High exposure Gomel vs. low exposure Vitebsk 1994; absolute rates Gomel 4.1% vs. Vitebsk 3% Annual dosesa,c not more than 10 mSv in highest area based on whole body monitoring presented in Wertelecki Bogdanovich 1997 [24]; Savchenko 1995 [25]
2. “Frequency of CM reflects environmental pollution level"
Increased frequency of malformations per 1000 births in Gomel contaminated territories 1982-1985 to 1987-1989:
Vetka 560%, Dobrush 170%, Khoiniki 230%, Chechersk 680%, and Elsk 200%; all Belarus less the contaminated areas 120%
Chechersky district (Gomel) Congenital malformations Investigation of 688 pregnancies and 7000 births in Chechersky (Gomel, Belarus) and Polessky (Kiev, Ukraine); sharp reductions in birth rates in both regions after Chernobyl ascribed partly to abortions; high perinatal mortality ascribed partly to congenital malformations; “incidence increased by a factor of 2 following the accident"; congenital heart disease, esophageal atresia, anencephaly, hydrocephaly and multiple malformations; total number of neonatal disorders increase in Plessky from 1983-1985 to 1986-1990 from 6.81 to 21.32 (313%) and in Chechersky from 5.15 to 10.49; no statistical data given Annual dosesa,c estimated at not more than 10 mSv Kulakov et al. 1993 [26]
 Mogilev Region Congenital malformations Retrospective analysis of all pregnanciesl 981 -1993 in high exposed Mogilev and Gomel vs. low exposed Brest and Vitebsk; excess CM in high exposure areas relative low exposure areas; CM rates increased before vs after: Gomel 150%, Mogilev 130%, Brest 120%, and Vitebsk 110% in rank of contamination; no statistical analysis Annual dosesa,c less than Gomel, perhaps 8 mSv in Mogilev, 3 mSv Brest, 1 mSv Vitebsk based on Belarus definition of normal Cs-137 in body Petrova et al. 1997 [27]
 Brest region Congenital malformations See above See above Shidlovskii et al. 1992 [28]
Ukraine
 Polissia region (Rivne) 8 Core EUROCAT defined malformations. Polissia vs.non-Polissiawith whole body monitoring 2000-2009 Polissia is region of Chernobyl contaminated Pripyat marshes; study of EUROCAT defined core malformations between two regions with whole body monitoring Cs-137 levels of Polissia 557 kBg, non-Polissia 155 kBg, 145437 live births; for 2000-2004 rates per 1000 births, NTD OR 1.59 (p<0.001), microcephaly OR 1.85 (p=0.01), micropthalmos OR 3.03 (p<0.05) Key study for assessing risk coefficient External cumulative dosesa by 2000 will have been 12 yr of 6.7 mSv=80 mSv in high dose area and 22 mSv in low dose area Wertelecki et al. 2010, 2014 [29,30]
See text for discussion Internal cumulative dosesc 36 mSv and 10 mSv
Totala,c high 90 mSv; low 32 mSv
 Polessky region (Kiev) Congenital malformations See Chechersky above See above Kulakov et al. 1993 [26]
 Lugyny region Congenital malformations Godlevsky et al. 1998 [31]
Turkey
 Bursa region Anencephaly, spina bifida Population of 90000 persons in Bursa region; rates increased from 1.7 to 9.2 NTD per 1000 births before Chernobyl to 20 in the first 6 mo of 1987 (n=12); most pronounced for anencephalus which increased 5-fold (n=6) <0.5mSvb Akar et al. 1989 [32]
 Aegean Turkey; Izmir Anencephaly, spina bifida 19115 Births in Izmir hospital Jun 1986-Jul 1988 rate of NTD before Chernobyl=1.9 per 1000 births; in May, Jun, Jul increased to 8.9 per 1000 births and subseguently returned to normal in 9 mo <0.5mSvb Caglayan et al. 1989 [33]
 Eastern Turkey; Elazig Anencephaly, spina bifida Prospective study 1985-1990, 5240 births rate prior to Chernobyl of NTD plus anencephaly 1.7 per 1000 (1.5 anencephaly); following Chernobyl became 6.9 per 1000 (5.5 anencephaly); peaked at 12.4 (8.9) in 1988 falling to 5.6 (4.2) in 1990 <0.5mSvb Giivenc et al. 1993 [34]
 Eastern Black Sea region Ankara Anencephaly, spina bifida 40997 Births; 1981-1986 NTD rates for NTD 2.12 per 1000 births and anencephaly 1.29 per 1000 births; after Chernobyl=4.39 and 2.46, p=0.0001 and 0.005, respectively <0.5mSvb Mocan et al. 1990 [35]
Bulgaria
 Pleven region Malformation of heart and central nervous system, multiple malformations “Significant increases after Chernobyl" guoted in Hoffmann 2001; no details of numbers <0.8mSvb Moumdjievet al. 1992 [36]
 Croatia Malformations by autopsy of stillbirth and neonatal death (perinatal) 3451 Perinatal autopsies at Zagreb Hospital; “increased freguencies in post-Chernobyl period"; no statistical data <0.5 mSvb Kruslin et al. 1998 [37]
Germany
 German Democratic Republic CLP Influence of radiation levels on CLP in newborns in former GDR 1980-1989; significant prevalence increase found in 1983 (F1 weapons fallout?) 1987 and 1988; 1987 showed an increase of 9.4% over mean rate since 1980; effect highest in areas with highest Cs-137 and Sr-90; all increases significant at the 5% level; levels of Cs-137 in Berlin measured at 6 kBg/m2 <0.3 mSvb Zieglowski et al. 1999 [38]
 Bavaria CLP In Bavaria CLP increased 9.5% from Oct 1986 to Dec 1990 relative to previous trend; p=0.1, not statistically significant; n=1324 cases; significant trend with fallout levels 1.008 per kBg/m2, p=0.03; confirmed by analysis of GDR and FGR data giving 8.6% increase 1984-1989; authors state this as proof of causation <0.3 mSvb 0.8 per 100 kBg/m2 which is external annual dosec of about 1 mSv Scherb et al. 2004 [39]
 Bavaria Congenital malformations For each Bavarian district (n=96) the ratio of the rates, more precisely the ORs, are calculated; results are regressed on surface contamination and show a biphasic relationship at low doses <0.3 mSvb Koerblein 2004 [40]
 West Berlin Malformations of stillborns No increase of cases with malformations in living births but an increase of the rate of malformations in stillbirths - 4.2 % in 1986, and 8.5 % in 1987 which is remarkable, because West Berlin had a nearly completely isolated population at that time; 21.6 % of the malformations in stillbirths were those of the extremities, 14.8 % distortions of the heart, 8 % hypospadias (distortion of ureter), 7.7 % clefts (194,356 births, 739 stillbirths) <0.3 mSvb Government of Berlin West 1987 [41]
 City of Jena Isolated malformations Regional registry showed increased rates 1986/1987 vs. 1985 of RR 4.1 (95% Cl, 1.16-14.56) levelling off in subseguent years; main increase in central nervous system and abdominal wall anomalies <0.3 mSvb Lotzet al. 1996 [42]

UNSCEAR, United Nations Scientific Committee on the Effects of Atomic Radiation; OR, odds ratio; CI, confidence interval; Cs-137, Caesium-137; Sr-90, Strontium-90; NTD, neural tube defects; F1, first generation; GDR, German Democratic Republic; FGR, Federal German Republic; CLP, cleft lip and palate; RR, relative risk.

a Mean first year committed effective doses are given by the authors or are calculated by us on the basis of information given by the authors using MicroShield and US Environmental Protection Agency FGR12 Part 2 [43] which gives the external dose rate over an infinite plane contaminated at 100 kBq/m2 as about 0.2 × 10-6 Gy h-1; we assume 16 hr/d exposure.

b These doses are taken from Figures 1 and 3 of Savchenko [25] and represent the mean countrywide first year (ICRP) committed Effective Dose.

c Internal doses for Cs-137 and Sr-90 calculated by us using the ICRP72 dose coefficients.

Table 2.
Congenital anomalies, especially malformations, in descendants (1st generationa) of occupationally exposed men
No. Cohort of fathers Kind of defect Dose References
1 Radiologists USA 1951 Congenital malformations Increase 20% Macht, et al. 1955 [54]
2 Workers of the Hanford Nuclear facility, USA Neural tube defects significantly increased by 100% In general <100 mSv Sever et al. 1988 [55]
3 Radiation workers at Sellafield nuclear reprocessing plant, UK Stillbirths with neural tube defects significantly increased by 69% per 100 mSv Mean 30 mSv Parker et al. 1999 [56]
4 Radiographers in Jordan Congenital anomalies significantly increased 10-fold Shakhatreh 2001 [57]
5 Liquidators from Obninsk (Russia), 300 children Congenital anomalies increased 1994-2002 Mainly 10-250 mSv Tsyb et al. 2004 [58]
6 Liquidators from Russia, Bryansk region Congenital anomalies increased about 4-fold Matveenko et al. 2006 [59]
7 Liquidators from Russia, 2379 newborns Significant increase for: anencephaly 310%, spina bifida 316%, cleft lip/palate 170%, limb reduction 155%, multiple malformations 19%, all malformations 120% 5-250 mSv Lyaginskaja et al. 2009 [60]
8 British nuclear test veterans All malformations Less than 10 mSv but internal Urquhart 1992 [61]
Down's syndrome
OR 1.6 for early vs. later births
9 British nuclear test veterans All congenital conditions increased Less than 10 mSv but internal Roff 1999 [62]
We estimate heart defect 4-fold
10 British nuclear test veterans case control/EUROCAT study Miscarriages odds 2.7 Less than 10 mSv but internal Busby et al. 2014 [63]
Congenital conditions: children OR 9.8; grandchildren OR 8.3a

a Mean first year committed effective doses are given by the authors or are calculated by us on the basis of information given by the authors using MicroShield and US Environmental Protection Agency FGR12 Part 2 [43] which gives the external dose rate over an infinite plane contaminated at 100 kBq/m2 as about 0.2× 10-6 Gy h-1; we assume 16 hr/d exposure.

Table 3.
Cancer in children after preconceptional low-dose exposure of parents
Exposed collective Malign disease Gonadal dose/mSv Relative risk Doubling dose/mSv
Seascale fathers [64] Leukaemia + lymphoma
 All stages of spermatogenesis 200 7 32
 6 mo before conception 10 1.9 1.6
Further occupational exposure of fathers
 Military jobs [66] Cancer 2.7
 Regions of UK [67] Leukaemia + lymphoma 3.2
Preconceptional X-ray diagnostics in Leukaemia
 Fathers 1966 [68] 1.3
 Fathers 1988 [69] 1.4-3.9
 Fathers 1994 [70] 3.8
 Mothers 1958 [71] 1.4 25
 Mothers 1966 [68] 1.7
 Mothers 1973 [72] 1.4
 Mothers 1980 [73] 2.6
Editorial Office
Department of Preventive Medicine and Public Health, Dankook University College of Medicine,
119 Dandae-ro, Dongnam-gu, Cheonan 31116, Korea
Tel : +82-2-740-8328, 3868   Fax : +82-41-556-6461   E-mail: envitoxic@gmail.com
About |  Browse Articles |  Current Issue |  For Authors and Reviewers
Copyright © 2017 by The Korean Society of Environmental Health and Toxicology. All rights reserved.     powerd by m2community