OBJECTIVE--To evaluate the outcome of pregnancy in Finnish women after the accident at the Chernobyl nuclear power plant on 26 April 1986. DESIGN--Geographic and temporal cohort study. SETTING--Finland divided into three zones according to amount of radioactive fallout. SUBJECTS--All children who were exposed to radiation during their fetal development. Children born before any effects of the accident could be postulated--that is, between 1 January 1984 and 30 June 1986--served as controls. INTERVENTIONS--Children were divided into three temporal groups: controls, children who were expected to be born in August to December 1986, and children who were expected to be born in February to December 1987. They were also divided, separately, into three groups according to the three geographic zones. END POINT--Incidence of congenital malformations, preterm births, and perinatal deaths. MEASUREMENTS AND MAIN RESULTS--There were no significant differences in the incidence of malformations or perinatal deaths among the three temporal and three geographic groups. A significant increase in preterm births occurred among children who were exposed to radiation during the first trimester whose mothers lived in zones 2 and 3, where the external dose rate and estimated surface activity of caesium-137 were highest. CONCLUSIONS--The results suggest that the amount of radioactive fallout that Finnish people were exposed to after the accident at Chernobyl was not high enough to cause fetal damage in children born at term. The higher incidence of premature births among malformed children in the most heavily polluted areas, however, remains unexplained.
Comment In: BMJ. 1989 May 20;298(6684):13842502266
Our objective was to explore whether the radiation fallout in Finland after the accident at the Chernobyl nuclear power plant in April 1986 led to an increased incidence of trisomy 21. In this geographic and temporal cohort study, the country was divided into three zones according to the amounts of radioactive fallout and internal radiation caused by two cesium isotopes. The 518 cytologically verified cases of trisomy 21 were divided into a control group (conceived before the accident), and a study group of children whose expected dates of birth were in the post-accident years 1987-1988, i.e., pregnancies commenced after May 1986. The cases were also divided into three subgroups according to the zones of radiation. There were no significant differences in prevalence of trisomy 21 between the control and study groups nor between the three zones in spite of the significant differences in the levels of radiation and in the body burden that prevailed throughout the study period. Power estimates showed that in the two zones of lower radiation, an increase of 0.5% in the prevalence would have been detected with a power of 0.85, and in the somewhat smaller zone of the highest radiation, with a power of 0.70. The study lends no further support to the view that the low radiation fallout in western Europe would have been causally associated with trisomy 21.
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.
The callus culture of Nicotiana tabacum L. was obtained from the plants chronically irradiated in 10 km zone of Chernobyl Atomic Power Station. The tobacco plants in 10 km zone of Chernobyl during the vegetation period exposed to irradiation with the average dose rate of 0.36 mA/kg (5 mP/h). The total absorbed dose was approximately 0,31 Gy. The morphogenetic analysis of this culture shows a considerable decrease of regeneration index and callus weight.
Detecting changes in humans that result from radioactive contamination of the area of residence many years after an incident (i.e., when the radiation has substantially decayed) presents a difficult epidemiological problem. Problems of this kind are even more complicated ina areas where the population is continually exposed to other harmful man-made factors. The city of Kamensk-Uralsky (Sverdlovsk region, Russia) is a good case in point. In 1957, part of Kamensk-Uralsky was contaminated as the result of an accident at the Kyshtym nuclear plant. In addition, the population of the contaminated area is being exposed to atmospheric emissions from several industrial enterprises. Two comparable groups of residents were formed: one in the contaminated are and another in a control area within the same city characterized by similar levels of chemical pollution but substantially lower radioactive contamination. The groups were composed of only those people who had been living in these areas continually since time of the accident and who were under 15 years of age at the time of the accident. The groups were matched by sex, age, and socio-occupational characteristics. For each subject, data were gathered on more than 50 parameters including hematological, immunological, and biochemical indices of the health status. All these data were obtained from blood tests taken in the fall of 1992. Data processing was carried out with the help of a computerized mathematical pattern recognition methodology, which ensured reliable discrimination between the generalized health status in the areas under study. We found that the health status of inhabitants of the area more contaminated with radioactive fallouts was adversely affected by radiation.
Cites: Am J Epidemiol. 1991 Oct 1;134(7):675-881951272
Cites: Med Lav. 1990 Mar-Apr;81(2):87-952250613
Cites: Environ Health Perspect. 1989 Jul;82:311-212676501
The permissible level of a radionuclide mixture, resulted from the Chernobyl burst, in the human being lungs was determined for two kinds of compounds: absolutely insoluble compounds and soluble compounds in the state of equilibrium. For this purpose the data were used concerning the radionuclide composition and aerosol disperse in lower atmosphere which were obtained by the Department for Dosimetric Control (NPO "Pripiat'"). The results of measurements of 137Cs content taken by the use of human radiation spectrometer (HRS) needed an adequate estimation: low level of 137Cs in the human lungs and body within the Chernobyl NPP, zone does not guarantee radiation security. The notion "permissible content" and the possibility of using thereof in the individual dosimetric control are discussed.
Cancer has long been known to be a hazard of exposure to ionizing radiation. However, the assessment of health effects from exposure to radiation is a matter of considerable controversy. This paper presents results of a retrospective study of leukemia incidence (203-207, ICD-9) around the highest 137Cs pollution in Poland (as an effect of the Czarnobyl disaster and/or military bomb tests). The data relating to all the registered leukemias in males and females originated from the Regional Cancer Registry in Opole. The information on 137Cs concentration rates in Opole province was derived from the state monitoring provided by the Polish Geological Institute in Warsaw. The spatial analysis--based on the random-effects Poisson regression model--was carried out via the Markov Chain Monte Carlo (MCMC) technique (Gibbs sampling) using BUGS software. The model incorporated epidemiological data and an ecological covariate--isotope concentrations--and provided a framework for estimating the strength of a dose-response relationship. The differences in incidence levels were quantified by traditional standardized morbidity ratios (SMRs) and presented in thematic maps as well as in combined charts of distance-disease-dose relations. Additionally, to assess spatial disease clustering, a Tango test was adopted. The results of this ecological study suggest that the 137Cs concentrations did not have any negative influence on the exposed population.