One of the populations most exposed to chronic low-dose radiation from Chornobyl (Chernobyl in Russian) lives in Polissia, the region representing the northern half of Rivne Province (Oblast) in Ukraine. Here the patterns and population rates of malformations are reported and possible etiologic factors and regional contrasts are explored.
Malformations, as defined by international standards, noted among all 96 438 births in Rivne between 2000 and 2006, were analyzed statistically. Contrasts of rates in Polissia compared with the rest of Rivne also were investigated.
The overall rate of neural tube defects in Rivne is among the highest in Europe (22.2 per 10 000 live births). The rates of conjoined twins and teratomas also seem to be elevated. In Polissia, the overall rates of neural tube defects are even higher (27.0 vs 18.3, respectively; odds ratio: 1.46 [95% confidence interval: 1.13–1.93]), and the rates of microcephaly and microphthalmia may also be elevated.
The malformation patterns observed suggest early disruptions of blastogenesis, manifesting as alterations of body axes, twinning, duplications, laterality, and midline formation. The results are sufficiently compelling to justify continuing and expanding this investigation of malformations in chronic low-dose radiation-impacted regions of Ukraine.
Aggressiveness or invasiveness of Chernobyl-related thyroid cancer (TC) in children and adolescents was reported in many publications [1-7]. Some more were referenced in [8]; while in this particular study no increased aggressiveness of TC developed after radiotherapy had been demonstrated [8]. The following was stated in [9]: "Despite early reports suggesting that the paediatric thyroid cancer cases that developed after exposure to Chernobyl fallout were particularly aggressive, it now seems that the initial presentation and early clinical course of most of these cases are very similar to... non-radiation-associated pediatric thyroid cancers..." Furthermore, "at diagnosis, 60-70% of the Chernobyl-related pediatric thyroid cancers had clinically evident cervical lymph node metastases" [9]. These figures are comparable with some data on pediatric TC [10] and higher than metastasizing percentages reported by others researchers [11,12], being high enough not to contradict to the concept of aggressiveness of Chernobyl-related TC or, alternatively, of an advanced stage at diagnosis. Another statement from [9]:"With regard to the size of the primary tumor, 77% were greater than 1 cm, suggesting that these were not incidental thyroid cancers detected by aggressive screening." It can be understood as an argument against the screening-effect. In fact, mass screening detected not only small incidental cancers but also advanced TC, previously neglected because of the incomplete coverage of the population by medical checkups before the accident, shortage of modern equipment, etc. [13] The screening-effect can explain also for the increase in malformation incidence after the Chernobyl accident [14]. This concept is in agreement with the reports that TC found at an earlier date after the accident had on average greater diameter and were less differentiated than TC detected later [5], and that "increasing latency" was associated with a decrease in invasiveness [7]. In conclusion, some features of Chernobyl- related pediatric cancer are associated not with ionizing radiation but with longer disease duration and tumor progression because of the on average later detection of malignancies in the former Soviet Union [15]. More details about food contamination after the Chernobyl accident are in [16].
References
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Conflict of Interest:
None declared
Dear Editor, I read the paper published by Professor Wladimir Wertelecki in an earlier issue of the PEDIATRICS entitled "Malformation in a Chornobyl-Impacted Region".1 The article describes the details of the population rates and types of selected malformation occurred during seven years period in Chornobyl region of Ukraine.
There is a leisure and sport complex (called Shorabil) in the city of Ardabil, northwest of Iran, where we used to go for sport and gym purposes some years ago. The city is almost the nearest place in our country, as a major city, to the location of Chornobyl region of Ukraine (Figure 1). This sport complex includes a relatively big pool around which there is a walkway for those doing sport, cycling, running, etc.
I remember we were always seeing some frogs around the pool with structural malformation. Some of them did not have a leg, some with malformed body shape etc.
It used to be a matter of question for us whether this has happened because of Chornobyl explosion of 1986. If so, there should have been the same impact on the human population in the area too. This has never been investigated either on animal or human populations in this region.
We have an established registry of birth defects in the northwest area of the country.2-3 We will be trying to expand our activities in the region (including Ardabil city) in the future to identify the occurrence of congenital malformation in the population level. However, until then, there is an urgent need for an action by scientists and responsible health authorities in the area for this matter.
Saeed Dastgiri
Reference
1. Wertelecki W. Malformation in a Chornobyl-Impacted Region. Pediatrics. 2010;125(4):836-843
2. Tabriz Registry of Congenital Anomalies. Available at: www.tbzmed.ac.ir/troca. Accessed April 3, 2010
3. Dastgiri S, Kalankesh LR, Heidarzadehe M, Tajahmade A, Rezaiane E. A New Registry of Congenital Anomalies in Iran. Journal of Registry Management. 2010; 37(1): 27-9
Conflict of Interest:
None declared