Assessment of natural radioactivity levels in rocks and their relationships with the geological structure of Johor state, Malaysia

Yerevan soil radioactivity: Radiological and geochemical assessment

Spatial pattern of naturally occurring radionuclides (NOR): ²²⁶Ra, ²³²Th, ⁴⁰K, and artificial ¹³⁷Cs was studied using soil samples of the multipurpose geochemical survey of the city of Yerevan, capital of Armenia. High purity Ge detector-based gamma spectrometry system was used for the determination of radionuclides activity concentrations in urban soils. A combination of compositional data analysis, geochemical mapping and radiological assessment were applied to reveal potential factors of technologically enhanced natural radioactivity and excess lifetime cancer risk for Yerevan's population due to NOR and artificial ¹³⁷Cs in the urban environment. Statistical methods with the geochemical mapping revealed the great contribution of soil-forming rocks to NOR distribution in urban soils. The spatial distribution of calculated radiological indices and dose rates levels follows the distribution patterns of NOR. The activity concentration of fallout radionuclide ¹³⁷Cs was within the range typical for the studied altitudes. Above baseline activity of ¹³⁷Cs was observed in the north-western and western part of the city that is in typical ranges of ¹³⁷Cs content in soil derived from global radioactive fallout. Urban soils of Yerevan were found radiologically safe, however, igneous rock derived soils are a sink of NOR and the main environmental source of continuous exposure to the residents. Values of excess lifetime cancer risk were higher than mean global value.

Indoor and outdoor radon measurements at lung cancer patients' homes in the dwellings of Rize Province in Turkey

In this study, indoor and outdoor radon (²²²Rn) surveys were carried out in the summer and winter seasons in homes of one hundred lung cancer patients in the year 2013-2014. The aim was to investigate the relationship between radon and cancer patients. Lung cancer patients completed a questionnaire concerning their living environment, various physical parameters and living habits. Pearson correlation and t tests revealed no meaningful results between radon concentrations, on one hand, and environmental and personal living habits, on the other hand. Consequently, the BEIR VI model was adapted and ²²²Rn exposure was estimated to be responsible for about 12% of the lung cancer incidences in the winter season and around 5% in the summer season in the Rize Province. However, due to the limited number of data and numerous parameters that could lead to lung cancer, the estimations done with the model should be taken very lightly. The annual effective doses due to inhalation of indoor and outdoor ²²²Rn were estimated to be, respectively, 1.43 and 0.94 mSv y^-1. The indoor and outdoor annual effective doses were, respectively, close and below the world annual effective dose (1.3 mSv y^-1). At the district level, the indoor annual effective dose equivalent in the İyidere district was 4.52 mSv y^-1, which was 3.5 times greater than the world average. The number of patients in the majority of the houses in this district was more than one.