Distribution of doses received by Cuban population due to environmental sources of radioactivity.

Doses received by Cuban population due to exposure to the environmental sources of radiation were studied for their evaluation. Estimations of doses from the different components of the total dose were obtained and published. From the results obtained estimations of total doses to Cuban population from environmental radiation sources and the contributions of different dose components were made. A Monte Carlo simulation of the sum of doses was carried out and the distribution of obtained values was assumed as a lognormal distribution. Parameters for characterisation of this lognormal distribution were estimated, and on the basis of the estimations the average total effective dose to the Cuban population owing to exposure to the environmental sources was estimated as 1.1 +/- 0.3 mSv y(-1). This low dose value is in the range of doses estimated by UNSCEAR for world population due to natural background and can be explained by the specifics of the Cuban environment.

Studies on internal exposure doses received by the cuban population due to the intake of radionuclides from the environmental sources.

Studies for the determination of radionuclide concentrations in foodstuffs, water and air were carried out in Cuba for the estimation of annual committed effective doses to members of the public as a result of environmental radionuclides via ingestion and inhalation. As a result of these studies, it was possible to determine the concentrations of 226Ra, 210Pb, 210Po, 232Th, 90Sr and 137Cs in different food groups that constitute the diet of the Cuban population, as well as the 222Rn concentrations in air. Based on these results and using previously obtained results for doses due to the 40K body content, the annual committed effective doses due to the intake of studied radionuclides were estimated. An average value of 120+/-4 microSv y-1 was obtained for doses due to ingestion of food and water and the obtained value for 222Rn inhalation was 240+/-1 microSv y-1. Using the representative value obtained previously for 40K (150+/-40 microSv y-1) and assuming a dose of 50+/-50 microSv y-1 for the probable contribution of 220Rn by inhalation, a representative value of 560+/-20 microSv was estimated for the average annual committed effective doses due to ingestion and inhalation of radionuclides for the Cuban population. Obtained values are consistent with the expected results, taking into account the characteristics of Cuban exposure scenarios, with low-activity concentration levels in environmental objects and high air exchange rates in dwellings: These results are in the same order of magnitude as results obtained by other authors and the reference values established by the USNCEAR.