EXPOSURE LEVELS OF UKRAINIAN POPULATION IN THE CONTEXT OF AN ACTION PLAN TO REDUCE INDOOR RADON LEVELS

Abstract

Objective. To analyze and evaluate the available information to indoor radon concentration in the context of the implementation of the radon action plan. Methods. Object of study: indoor radon-222 in dwellings by area and corresponding radiation risks of the population. Measurements were performed using passive track radonometry. The exposure time of the radonometers is at least 30 days during heating season. Radiation risk calculations were performed according to the dose coefficients and mathematical models of the ICRP. Results. It was found that for the whole country, reference level 300 Bq/m3 (radon gas) is exceeded in 16 % of cases. It was found that geometric mean of radon gas levels was 120 Bq/m3 and varies from 35 to 265 Bq/m3 by different area, namely the difference between radon levels in different territories of the country can be up to 7.5 times. Variability of radon levels at the district level is also significant. It was found, radon activity concentration differing by almost 10 times by districts with lognormal distribution and a geometric mean of 75 Bq/m3. The analysis of radiation risks of the population has established that estimated annual number of lung cancer deaths due to radon in Ukraine is almost 8,900 cases; and а direct economic loss for the country are estimated at more than $ 450 million a year. Conclusions. Surveys of radon levels demonstrated significant variation in radon concentrations between different regions. For the whole country, reference level (300 Bq/m3) is exceeded on above 16 % of the dwellings, but percentage of exceeding varies from 0.1 to 43.0 % by different area. Information on indoor radon concentrations in almost a third of the country is non-available. For an effective implementation of the Action plan, it makes sense to introduce radon risk mapping. Key words: indoor radon, reference level, population, radiation risk, economic cost.