Problems of Radiation Medicine and Radiobiology

Prysyazhnyuk A. Ye., Fuzik1 M. M., Gudzenko N. A., Bazyka D. A., Fedorenko Z. P., Ryzhov A. Yu., Sumkina O. V., Trotsyuk N. K., Khukhrianska O. M.

Experience of study of the incidence of malignant neoplasms population in small areas of Ukraine, which suffered contamination with radionuclides due to the Chornobyl accident

Objective. To evaluate the dynamics of implementation risks of malignant tumors in some small areas of Ukraine in the pre- and post-accident period.
Materials and methods. The study population group – the population of the Malyn rayon, Zhytomyr region. The period of observation covered 1980–2014. There was investigated the incidence of malignant tumors in general and individual nosological forms (thyroid cancer, breast cancer, tumors of hematopoietic and lymphoid system). Methods of variation statistics and descriptive epidemiology were used.
Results. Characteristics of ionizing radiation influence on the population of Malyn rayon indicate the potential for negative effects, especially for thyroid cancer. Besides the fact that the average total effective radiation dose whole body by radioactive cesium in Malyn rayon population (5.9 mSv) are at medium level in Zhytomyr region and is significantly lower in comparison with those of other areas of the northern part of the oblast, the exposure of thyroid  236 mGy, is significantly higher than the regional figures – 81 mGy. Although the level of morbidity Malyn rayon of malignant tumors in general was about at the national level for 1999–2003 and lower it in the 2012–2014, exceeding the figures of Zhytomyr region, the incidence of thyroid cancer in the 2012–2014 in Malin area was 1.7 times higher in comparison with data for Ukraine and in 1.9 times in comparison with the data in Zhytomyr region. As in most northern areas that fell under radioactive iodine fallouts, there is the realization of increased radiation risk of cancer of this organ. The incidence of breast cancer in female population Malyn rayon is the lowest in comparison with Ukraine and Zhitomir regions. However, the rate of increase in this area is the highest.
Conclusions. The results indicate the need for further monitoring of occurrence of cancer cases in the population of not only Ukraine as a whole, or large administrative units, but also among the population in small areas, taking into account the probability of the realization of risks of radiation-associated disease cases according to local environmental conditions.

Key words: Chornobyl accident, radiation exposure, malignant neoplasms, residents of contaminated with radionuclides territories.

Problems of radiation medicine and radiobiology. 2015;20:229-240.