Distribution of norm and 137Cs in soils of the Visakhapatnam region, Eastern India, and associated radiation dose

Monitoring of outdoor natural gamma absorbed dose rate in air in Hyderabad, Telangana, India

The Indian Environmental Radiation Monitoring Network continuously monitors the outdoor natural gamma absorbed dose rate in air at different locations throughout India by employing Geiger-Mueller (GM) detector-based field-installed environmental radiation monitors (ERMs). Hyderabad, Telangana, India is known to have high natural background radiation levels due to the presence of high concentrations of primordial radionuclides in its granitic rocks. There are a total of 59 ERMs installed at various locations across Hyderabad. Long-term monitoring data of these locations are presented in this paper. The mean values of outdoor natural gamma absorbed dose rate in air at the monitoring locations were found to vary in the range of 104-258 nGy.h-1 with a mean of 193 ± 40 nGy.h-1. The mean annual effective dose due to outdoor natural gamma radiation was estimated to be 0.24 ± 0.05 mSv.y-1. Analysis of the long-term seasonal variation of outdoor natural gamma absorbed dose rate in air showed that the same was lowest during monsoons.

Countrywide monitoring of absorbed dose rate in air due to outdoor natural gamma radiation in India

The Indian Environmental Radiation Monitoring Network continuously monitors, throughout India, the absorbed dose rate in air due to outdoor natural gamma radiation, by using Geiger-Mueller detector-based standalone environmental radiation monitors. The network consists of 546 monitors spread across 91 monitoring locations distributed all over the country. In this paper, the countrywide long-term monitoring results are summarised. The measured mean dose rate of the monitoring locations followed a log-normal distribution and ranged from 50 to 535 nGy.h-1 with a median value of 91 nGy.h-1. Due to outdoor natural gamma radiation, the average annual effective dose was estimated to be 0.11 mSv.y-1.

Anthropogenic accumulation based on chemometrics of the radionuclide K-40 in tropical soils in the northeast Brazil

The continuous use of fertilizers can increase the radionuclides levels in soils, and their accumulation and concentration are related to their characteristics and the various processes of use and soil occupation. Analyzing data from radiometric and pedological measurements often demands the use of more robust tools for better integration of results. This work presents the results of a study to evaluate the accumulation of ⁴⁰K, in an area of the Zona da Mata region in Pernambuco, Northeastern Brazil, due to the contribution of natural or artificial sources. ⁴⁰K activity concentration was measured by high resolution gamma spectrometry in 108 soil samples, as well the organic matter content and particle size distribution. Results showed the ⁴⁰K activity ranged from 103 to 1843 Bq.Kg^-1, with the arable soils showing levels above the world average value (420 Bq.Kg^-1). A higher prevalence of ⁴⁰K was observed on arable soils, regardless of soil type, organic matter content, depth or texture. Agricultural activities increased of ⁴⁰K levels in different degrees, depending on the type of crop used, with an accumulation factor of up to 4 times greater compared to soils not impacted by agricultural activities. The radiochemometric diagnosis maded it possible to draw up a strategic management plan to improve the management practices of family farming in order to maximize production efficiency, and promote the conservation of natural resources and environmental preservation.

BASELINE EVALUATION STUDY OF NATURALLY OCCURRING RADIONUCLIDES IN SOIL SAMPLES FROM VICINITY OF INDIA'S FIRST FAST REACTOR FUEL CYCLE FACILITY (FRFCF), DAE COMPLEX, KALPAKKAM, INDIA

The activity concentration of 238U, 232Th and 40K were measured in the soil samples collected from Fast Reactor Fuel Cycle Facility (FRFCF) site, using high-resolution gamma-ray spectrometry. This study is aimed to establish the baseline data of naturally occurring radionuclides within the site. The average activity concentrations were found to be 416.5, 61.7 and 622.3 Bq kg-1 for 40K, 238U and 232Th, respectively. The activity concentrations and its radiological indices were evaluated and were compared with the international values reported by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The ratio of 40K/232Th and 40K /238U were calculated, which indicates the presence of 5.79 and 2.69 times more K-bearing minerals as compared with Th and U-bearing minerals in the soil samples, respectively. The study provides baseline information on concentration of radionuclides and background radiological assessment of the FRFCF site.

Natural radionuclide activities in forest soil horizons of Mount IDA/Kazdagi, Turkey

Natural radioactivity distribution of (40)K, (238)U, and (232)Th isotopes in forest soils was investigated by using gamma-ray spectrometry. An extensive radioecological study was carried out between 2010 and 2013 in Mount IDA/Kazdagi, located in Edremit region in Turkey. A total of 341 soil samples were collected from the surface and organic horizons (OL, OF+OH, and A) in 118 soil profiles. The distributions of natural radioactivity levels in these horizons and corresponding absorbed dose rates from outdoors terrestrial gamma radiation throughout the region were mapped in detail. Mean (40)K activity values over the combined horizons varied between 43 and 1,008 Bq kg(-1); whereas, mean (226)Ra and (232)Th concentrations over the combined horizons ranged between 5-152 and 6-275 Bq kg(-1), respectively. Our data indicate that the radioactivity values of the study sites were within the universal normal range. The significant variation among the (232)Th, (226)Ra, and (40)K activities and gamma dose rate might be due to the geological variation in the study sites.