State Institution "Ukrainian Research Institute of Industrial Medicine", Kryvyi Rih
Introduction. Radon and its daughter decay products was recognized as the main source of radiation hazard for the population by the Scientific Committee on Atomic Radiation (UNSCEAR) in 1977. According to the information from the 115th report of the International Committee on Radiation Protection radon and its daughter decay products can cause lung cancer. The problem with radon for Kryvbas region is rather important because of the iron ore mining, presence of mines and quarries and specific character of construction of residential settlements.
The purpose of the study was to identify the risk of morbidity of lungs tumor neoplasms among the population of Kryvyi Rih under exposure to radon and its daughter decay products.
Materials and methods of research. Main indicators of morbidity of lungs tumor neoplasms (TN) in citizens of Kryvyi Rih , according to the data of the Cancer Register of Kryvyi Rih Oncology Dispensary, have been analyzed and compared with those among citizens of Dnipro, Dnipropetrovs'k region and Ukraine as a whole over the fifteen-year period. The statistical processing of the results was made by general methods of epidemiology. The relative risk (RR) value has been determined, which characterizes the correlation between the effect of harmful factors and a disease, including an etiologic fraction (EF). When studying statistical interrelations between indices of morbidity of TN and levels of radon in the air of buildings a value of a direct linear correlation coefficient has been obtained.
Results. The overall incidence of tumor neoplasms (TN) in Kryvyi Rih and Dnipropetrovsk region has been significantly increased within 1993-2007. The high rate of TN in the population of Kryvyi Rih was found as compared to Dnipro (p <0.01) and Ukraine (p <0.05, RR = 1.14 at CI 1.10-1.19). The average rate of lung cancer in Kryvyi Rih has been significantly higher within 10 years (1997-2006) as compared to Dnipro (p <0.01), Dnipropetrovsk region (p <0.05) and Ukraine (p < 0.01, RR = 1.24 at CI 1.11-1.37), while the average mortality rate from TN in Kryvyi Rih is significantly higher as compared to Dnipro (p <0.01) and Ukraine (p <0.01, RR = 1.25 at CI 1.12-1.41). Among many reasons causing cancer morbidity, including lung cancer, these are living conditions, the air condition, in particular. The correlation analysis revealed that the coefficient of the direct linear correlation (r) for inhabitants, residing in one-storey houses, is 0.72 (p <0.01), for inhabitants residing on the ground floors of multi-storey buildings is 0.81, and for five-storey panel houses with very high levels of radon-222 above the ground floor - 0,91. The determined values of correlation coefficients prove the evident link between the influence of the harmful factor (radon-222) and lung cancer rate among the population of Kryvyi Rih.
Conclusions. The research has revealed that in Kryvyi Rih, which is characterized as a radon-dangerous region by radon levels in residential areas, a statistically significant increase of lung cancer rates in comparison with the national indicators is recorded. The increased relative risk of morbidity and mortality because of lung cancer in the male and female populations of Kryvyi Rih as compared to Ukraine as a whole has been determined. The obtained values of the direct linear correlation coefficient confirm the correlation between the effect of the harmful factor (radon) and lung cancer rates among the population of the industrial region with intensive iron ore mining.
Keywords: risks, radon, danger, lung cancer, iron ore region, population of the iron ore region.
ORCID ID of author of the paper:
Ishchenko L.O. (ORCID ID 0000-0002-1303-2031)