Reconstruction of national distribution of indoor radon concentration in Russia using results of regional indoor radon measurement programs

Assessment of indoor radon exposure in South Korea

The objective of this study is to update the national and regional indoor radon concentrations in South Korea and assess indoor radon exposure. Based on the previously published survey results and the collected measurement data of surveys conducted since 2011, a total of 9271 indoor radon measurement data covering 17 administrative divisions are finally used for analysis. The annual effective dose from the indoor radon exposure is calculated using dose coefficients recommended by the International Commission on Radiological Protection. The population-weighted average indoor radon concentration was estimated to be a geometric mean of 46 Bq m^-3(GSD = 1.2) with 3.9% of all samples showing values exceeding 300 Bq m^-3. The regional average indoor radon concentration ranged from 34 to 73 Bq m^-3. The radon concentrations in detached houses were relatively higher than those in public buildings and multi-family houses. The annual effective doses to the Korean population due to indoor radon exposure were estimated to be 2.18 mSv. The updated values in this study might better represent the national indoor radon exposure level in South Korea because they contain more samples and cover a wider range of geographical areas than previous studies.

Improved semi automatic approach to count the tracks on LR-115 film for monitoring of radioactive elements

An improved semi automatic technique for counting the tracks formed on LR-115 films with the advantages of simplicity and speed is reported. In this technique, a microscope with a Dino-Eye eyepiece camera is coupled to a PC equipped with a python compiler. After etching of the LR-115 film, 16 track images were taken to find the track density. The images generated were binarized before application of a Python algorithm. This process does not disfigure the original track and increase the spatial resolution. The batch process option in Jasc Paint Shop Pro was used to binarize the 16 images simultanously. The Python program automatically counts the total number of tracks formed on the 16 track images. This method was compared with manual counting and counting with the software program-Scion image to verify it. The results showed that the proposed method is reasonably good at counting the tracks. It is a faster and less time-consuming method, and will facilitate measurements of etched tracks in a variety of applications.

Reanalysis of residential radon surveys in China from 1980 to 2019

A study on the published historic data of the residential radon concentration was carried out in order to provide a systematic retrospect and the confluent analysis of the investigations from 1980 to 2019 in China. A new database was established by collecting the results of nearly all radon surveys reported in China. A total of 129 surveys on residential radon, covering 147 cities with the sampling size of 72,295 were collected into the data pool for secondary analysis. The results from different decades confirmed the rapid increase trend of residential radon concentration in China. The geographical coverage, the sampling density and the geographic distribution of sampling sites of these surveys were discussed. The analysis on the local data sequences indicated the average increasing rate of residential radon concentration for 28 Chinese cities was estimated to be 0.80 Bq·m^-3·a^-1 in last 40 years. The results in this study provided the overall expression of the radon investigations in China and were expected to be benefit to the radon-related studies in the future.

First indoor radon mapping and assessment excess lifetime cancer risk in Iran

Radon (222Rn) is believed to be the main contributor to lung cancer second to smoking. The first national indoor radon map derived from some scattered regional radon surveys in Iran. The arithmetic mean of indoor radon concentration was calculated to 117.4 ± 97.7 Bq/m3. The mean excess life time cancer risk (ELCR) values were found to be in the range of 0.1%-4.26%, with an overall average value of 1.01%. The mean radon-induced lung cancer risk was 46.8 per million persons. Absence of sufficient indoor radon data showed that national wide monitoring programs should be activated in uncovered areas. Meanwhile, in order to provide further baseline values for radon mapping, we attempted to survey the radon levels inside 50 dwellings of Shabestar County in northwest of Iran. The investigation was also focused on the effects of some buildings related variables. The radon levels recorded varied from 3.92 to 520.12 Bq/m3, with a mean value of 56.19 ± 45.96 Bq/m3. In 9% of dwellings radon concentration exceeded 100 Bq/m3, the limit recommended by the World Health Organization. The average annual effective dose received by the residents of studied area was calculated to be 1.4 mSv. The ELCR was estimated to be 0.54%.

Qualitative overview of indoor radon surveys in Europe

The revised European Directive from 2013 regarding basic safety standard oblige EU Member States to establish a national action plan regarding the exposure to radon. At the same time, International Atomic Energy Agency started technical projects in order to assist countries to establish and implement national radon action. As a consequence, in recent years, in numerous countries national radon surveys were conducted and action plans established, which were not performed before. In this paper, a qualitative overview of radon surveys performed in Europe is given with a special attention to the qualitative and conceptual description of surveys, representativeness and QA/QC (quality assurance/quality control).

Radon, smoking and HPV as lung cancer risk factors in ecological studies

OBJECTIVES

Cohen's ecological analyses revealed negative correlation between the lung cancer mortality and average indoor radon concentration in the US counties, that contradicts to linear non-threshold (LNT) model and is inconsistent with results of case-control studies. The aim of this study was to analyze dependence between radon exposure and lung cancer mortality rate taking into account more complete data on smoking and new findings on association of the lung cancer with human papillomavirus (HPV) infection.

MATERIALS AND METHODS

Information on the cancer rates in the US counties and Russian oblasts, smoking prevalence and indoor radon concentration was found in literature. The cervix cancer incidence rate was used as surrogate of the HPV infection prevalence. The analysis included calculation of the coefficients of linear dependence between radon exposure and lung cancer mortality rate with adjustment to smoking and HPV infection prevalence.

RESULTS

After adjustment for the most relevant data on smoking and HPV infection, correlation between the lung cancer mortality and indoor radon was found to be consistent with results of the case control studies.

CONCLUSIONS

Analysis of geographically aggregated data on the lung cancer mortality and radon concentration in dwellings with adjustment to the significant risk factors confirms both the linear non-threshold dependency and results obtained in studies with individual accounting for the smoking and radon.

Effect of energy-efficient measures in building construction on indoor radon in Russia

The effect of implementation of energy-efficient measures in building construction was studied. Analysis includes study of indoor radon in energy-efficient buildings in Ekaterinburg, Russia, and results of radiation measurements in 83 regions of Russia conducted within the regional programmes. The forecast distribution of radon concentration in Ekaterinburg was built with regard to the city development programme. With Ekaterinburg taken as representative case, forecast distribution of radon concentration in Russia in 2030 was built. In comparison with 2000, average radon concentration increases by a factor of 1.42 in 2030 year; percentage above the reference level 300 Bq/m3 increases by a factor of 4 in 2030 year. It is necessary to perceive such an increase with all seriousness and to prepare appropriate measures for optimization of protection against indoor radon. Despite the high uncertainty, reconstructed distribution of radon concentration can be applied for justification of measures to be incorporated in the radon mitigation strategy.