The Chernobyl nuclear power plant accident happened on April 26, 1986. We investigated the cause of the striking increase in frequency of thyroid cancer in children who lived within a 150 km radius of Chernobyl and who were born before and after the accident. No thyroid cancer was seen in 9472 children born in 1987-89, whereas one and 31 thyroid cancers were recorded in 2409 children born April 27, 1986, to Dec 31, 1986, and 9720 born Jan 1, 1983, to April 26, 1986, respectively. Short-lived radioactive fallout caused by the Chernobyl accident probably induced thyroid cancer in children living near Chernobyl.
The level of radiation exposure in children in Belarus caused by the Chernobyl accident was investigated on the basis of whole body 137Cs count. The subjects were 10,062 children (4,762 boys and 5,300 girls) in Mogilev and Gomel, Belarus, who received Chernobyl Sasakawa Health and Medical Cooperation Project health examinations from May 1991 to December 1992 and who were 5-16 y old at the time of examination. The median whole body 137Cs count per body weight varied from 21-48 Bq kg-1 and from 28-126 Bq kg-1 in Mogilev oblast and Gomel oblast, respectively. (The "oblast" is the largest administrative district constituting the country. Belarus consists of 6 oblasts). Corresponding annual effective dose equivalents were all less than the public dose limit of 1 mSv y-1, but the observed levels in the children were considerably higher than the average level of 2.3 Bq kg-1 reported in the past for the former Soviet Union.
Comment In: Health Phys. 1995 May;68(5):733-57730075
The chromosome dicentric aberrations in the lymphocytes and levels of antibodies to human thyroid microsomal antigen in the serum of the children lived in the area of Bryansk Province suffered from the Chernobyl accident was examined. Correlation between those tests was not estimated: the autoantibodies were revealed in group with dicentrics and without those in 4.0% and 4.5% of cases correspondingly. Antimicrosomal antibodies were revealed more frequently (5.0%) and in higher titers in the children from the more polluted Bryansk Province than in those from Kaluga Province (3.1%). These data can testify about the role of inside radiation of thyroid gland in appearance of autoimmune thyroiditis signs.
[Activities of the Byelorussian scientific association of phthisiatrists and the phthisiatric organization of the Republic in the circumstances of complicated critical state of tuberculosis in connection with the Chernobyl AES accident]
This report examines the claim that Irish mortality in the second quarter (April-June) of 1986 increased due to the cloud of radioactive material released by the damaged reactor in Chernobyl. Over the period 1971-1987, based on date of registration, the death rates in the second quarter showed marked year to year variation often exceeding that expected on the basis of chance alone. In 1986 the percentage of annual deaths occurring between April and June, and the death rate itself, were both significantly higher than in most other years between 1981 and 1987. The 1986 figures were not however, significantly higher than those observed in years prior to 1981. Since the distribution of mortality by cause was not consistent with the hypothesis relating low level radiation to immediate mortality, and since causality cannot be inferred from a temporal association per se, the Chernobyl accident cannot be implicated in the excess mortality observed in the second quarter of 1986.
About a two years later after the reactor accident in Chernobyl we carried out a three-year cytogenetical study of children, dwelling in two regions of Ukraine where the radiation fallout occurred. Chromosome analyses of these individuals have shown a significant increase of the frequency of aberrant cells and chromosomal type aberrations in comparison to the control. We have discovered the increase of the level of chromosomal type aberrations, extension in spectrum of complicate aberrations of chromosome (dicentrics, rings and exchange aberrations) with the years and the increase with the years a share of children with various chromosomal abnormalities. Analyses of sister chromatid exchanges (SCE) and a replication index (RI) show a significant increase of RI meaning with the years in comparison to the control. The SCE frequency didn't altered as compared to the control during different years of investigation.
The children living in 4 regions of Russia contaminated as a result of the Chernobyl catastrophe were investigated. The control group consisted of the children of 2 regions which did not undergo this influence. The investigations were made 1-3 years after the catastrophe took place. An increase of etiologically non-clear asthenic-vegetative disorders was determined in the regions of radiation contamination. They were observed mainly among the children who had light residual organic cerebral deficiency. The authors cannot exclude the impact of the psychogenic factors.
For evaluation of the possibility of the appearance of autoimmune thyroiditis in children and juveniles lived in the areas of Kaluga Province [correction of region] suffered from the Chernobyl accident the content of antibodies to human thyroid microsomal antigen was investigated. Percentage of positive sera varied from 4.8% to 1.2% during 6 years. There is significant difference in the frequency of the antibody appearance between persons suffered from radioactive iodine and unsuffered ones. Correlation between levels of antimicrosomal antibodies and radiation dose obtained from incorporated radioactive iodine was not estimated.