Measurement of natural radioactivity and radiation hazard assessment in the soil samples of Visakhapatnam,Andhra Pradesh,India

The present work aims to measure and estimate radioactivity and hazardous radiation indices of the soil. Soil samples were collected from various locations in the Visakhapatnam district in Andhra Pradesh, India. The measurement of specific activity of ²²⁶Ra, ²³²Th, and ⁴⁰K radionuclides is carried out with the help of HP-Ge based gamma spectrometer system. Activity concentration of radionuclides in the samples ²²⁶Ra, ²³²Th and ⁴⁰K ranged from 20 ± 2 to 91 ± 2 Bq.kg^-1, 45 ± 3 to 365 ± 3 Bq.kg^-1, and 400 ± 9 to 607 ± 8 Bq.kg^-1, and the respective mean values are 53.36 Bq.kg^-1, 203.74 Bq.kg^-1 and 479.19 Bq.kg^-1. The measured mean value of the absorbed dose rate is 171.41 nGy.h^-1, which was beyond the worldwide mean outdoor value of 60 nGy.h^-1. Thus, the annual effective dose estimated from the above value is 1.04 mSv.y^-1. The correlation was done among the measured ²²⁶Ra, ²³²Th, and ⁴⁰K activity concentrations. The estimated radium equivalent dose is 381.60Bq.kg^-1. The estimated health hazard index and annual effective dose rates of dwellers of Visakhapatnam were studied and compared to Indian average values. The study will help to generate the baseline data for assessing hazard indices to the public and geological mapping of natural radiation in India.     

Assessment of natural radioactivity in soil samples and comparison of direct and indirect measurement of environmental air kerma rate

This study presents the high purity germanium (HPGe) gamma spectrometric measurement of natural radioactivity mainly due to ²²⁶Ra, ²³²Th and ⁴⁰K in soil samples collected in Ferozepur and Faridkot district of Punjab, India. ²²⁶Ra activity varied from 28.6 to 51.1 Bq kg⁻¹ with the mean of 39.7 Bq kg⁻¹. The range and mean activity of ²³²Th were 42.9–73.2 and 58.2 Bq kg⁻¹, respectively. ⁴⁰K activity was in the range of 470.9–754.9 Bq kg⁻¹ with the mean of 595.2 Bq kg⁻¹. The air kerma rate (AKR) at 1 m height from the ground was also measured using gamma survey meter in all the sampling locations, which was ranging from 92.1 to 122.8 nGy h⁻¹ with the mean of 110.6 nGy h⁻¹. The radiological parameters such as Ra_eq and activity index of the soil samples were also evaluated, which are the tools to assess the external radiation hazard due to building materials. The mean and range of the Ra_eq values were 168.7 and 132.9–210.4 Bq kg⁻¹, respectively, whereas the activity index varied from 0.5 to 0.8 with the mean value of 0.62. These indices show that the indoor external dose due to natural radioactivity in the soil used for the construction will not exceed the dose criteria. The AKR was also evaluated from soil activity concentration and altitude correction of cosmic radiation contribution. The statistical tests such as Pearson correlation, spearman rank correlation, box and whisker plot, the Wilcoxon/Mann–Whitney test and chi-square test, were used to compare the measured AKR with evaluated AKR, which indicates good correlation.     

Radiological assessment of natural and fallout radioactivity in the soil of Chamba and Dharamshala areas of Himachal Pradesh,India

This paper presents the results of measurement of natural and fallout radioactivity in soil samples of Chamba and Dharamshala areas in Himachal Pradesh, India. Spatial distribution of ²³⁸U, ²²⁶Ra, ²³²Th, ⁴⁰K, ¹³⁷Cs was determined using High resolution gamma-ray spectrometry. The mean activity concentration in Chamba region due to ²³⁸U, ²³²Th, ⁴⁰K and ¹³⁷Cs was 32.3, 58.4, 588.3, and 10.9 Bq kg⁻¹, respectively, whereas in Dharamshala it was 35.7, 61.3, 594.9, 10.0 Bq kg⁻¹, respectively. Absorbed gamma dose rate (D) in air was calculated using appropriate dose conversion factors, which was varying from 45 to 103 nGy h⁻¹. To control the radiation exposure due to natural radioactivity in soil, if it is used as building materials, radium equivalent activity (Ra_eq) and activity index were also evaluated. Radium equivalent activity calculated for the soil ranged from 95.5 to 234.2 Bq kg⁻¹ with average of 171.0 Bq kg⁻¹.The calculated Activity concentration index was ranged from 0.34 to 0.85 with an average value of 0.64. The natural and fallout radioactivity in soil of this region is comparable with Indian average and other parts of the world. The percentage contribution of ²³⁸U, ²³²Th and ⁴⁰K and ¹³⁷Cs to the average external gamma dose rate was 22, 46, 32, 2%, respectively. This shows that the dose contribution due to fallout radioactivity is negligible as compared to the natural radioactivity.     

Assessment of natural radioactivity and heavy metals in water and soil around seismically active area

The natural radioactivity concentration and some heavy metals in various water and soil samples collected from seismically active area have been determined. Gross-alpha and beta concentrations of different 33 water samples and some heavy metal (Fe, Pb, Cu, K, Mn, Cr and Zn) concentration in 72 soil samples collected from two major fault systems (North and East Anatolian Active Fault Systems) in Turkey have been studied. This survey regarding gross-alpha and beta radioactivity and some heavy metals concentrations was carried out by means of Krieger method using a gross-alpha and beta-counting system and atomic absorption spectrometry (AAS), respectively. Also, gross annual effective dose from the average gross-alpha activity in waters were calculated.     

Radiation hazards and natural radioactivity levels in surface soil samples from dwelling areas of North Cyprus

Journal of Radioanalytical and Nuclear Chemistry - Due to increasing concern about environmental radiological protection, radioactivity concentrations of 226Ra, 232Th, 40K and 137Cs in surface soil...     

Natural and fallout radioactivity measurement in Indian soils

The paper presents the results of high resolution gamma-spectrometric measurements of ¹³⁷Cs, ⁴⁰K, ²³²Th and ²³⁸U in Indian soils collected from 24 different places from normal natural radiation background areas. The depth profile of ¹³⁷Cs was studied at sampling sites. The paper also presents ¹³⁷Cs levels in top soil at Mumbai during 1986 to 2000. The results in Mumbai soil indicate clearly the accumulation from fallout only on the top soil and seasonal peaking during the beginning of the monsoon season.     

Assessment of natural radioactivity in silt samples from Moticher lake near Kakrapar Atomic Power Station,India

The naturally occurring radioisotopes such as ²³⁸U, ²³²Th and ⁴⁰K in the silt samples collected from Moticher lake, Gujarat were evaluated. The activity of ²³⁸U, ²³²Th and ⁴⁰K was found to be 4.4-9.7 Bq kg⁻¹ with a mean 6.4 ± 1.3 Bq kg⁻¹, 10.5–21.2 Bq kg⁻¹ with a mean 15.6 ± 2.5 Bq kg⁻¹ and 102–231 Bq kg⁻¹ with a mean 160 ± 40 Bq kg⁻¹, respectively. The depth profile study could not reveal any significant vertical correlation on radioactivity levels of ²³⁸U, ²³²Th and ⁴⁰K. Radium equivalent activity (Ra_eq), external hazard index (H _ex) and internal hazard index (H _int) were calculated by using the activity of ²³⁸U or ²²⁶Ra, ²³²Th and ⁴⁰K in silt samples. Annual Effective Dose Equivalent (AEDE) level in Moticher silt was found to be 24.8 ± 5.0 μSv year⁻¹, which is much lower than the worldwide average value. The relative contribution to dose due to ²³⁸U and ²³²Th series were found to be 14% and 53%, followed by the contribution of 33% due to ⁴⁰K.     

Natural radioactivity in soil samples of Kocaeli basin, Turkey

The city of Kocaeli is in the western part of Anatolia in Turkey and has a population of approximately 1.000.000. There is no information about radioactivity in the Kocaeli soils samples so far. For this reason, the concentrations of the natural radionuclides in soil samples from 27 different sampling stations in Kocaeli Basin and its surroundings have been determined. The results have been compared with other radioactivity measurements in different country"s soils. The typical concentrations of ¹³⁷Cs, ²³⁸U, ⁴⁰K, ²²⁶Ra, ²³²Th found in surface soil samples ranged from 2±0.6 to 25±6 Bq/kg, from 11±4 to 49±10 Bq/kg, from 161±30 to 964±127 Bq/kg, from 10±4 to 58±11 Bq/kg, and from 11±3 to 65±13 Bq/kg, respectively.     

Natural radioactivity studies of Bidar soil samples using gamma spectrometry

The activity of the terrestrial primordial radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K are measured for Bidar soil samples. The collected soil samples are analyzed using HPGe detector based on high resolution gamma spectrometric system. The activity of the three radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K were found to be in the range of BDL–47.68, 7.65–59.08 and BDL–260.65 Bq kg^?1 respectively. The mean gamma absorbed dose rate in air above 1 m from ground is estimated to be 34.47 nGy h^?1. Annual effective dose equivalent and the radium equivalent activity were within the limits in the present study and it is found that the activity of the radionuclides are comparable with the worldwide literature values. Also the external hazard indices for the soil samples of Bidar district were within the limit of unity.     

Assessment of radioactivity contribution and transfer characteristics of natural radionuclides in agroecosystem

Taking into account the importance of distribution and transfer of radionuclides in the soil–plant system, especially in agricultural fields, the aim of this research was assessment of radioactivity contribution and transfer characteristics of natural radionuclides in agroecosystem. The measurement of the natural radioactivity distribution was conducted in organic and sustainable farming management systems. Statistical evaluation of the physical and chemical properties of soils subjected to different farming systems, revealed the existence of differences in some parameters. Balanced distribution of natural radionuclides in soil-crop system was observed. Radionuclide ⁴⁰K was the most accessible to the investigated crops via uptake from the soil, then ²³²Th and ²²⁶Ra. The obtained results are useful for understanding the behavior of the radionuclides and provide an insight into the cumulative deposition of radioactivity in the agroecosystem.

     

Measurement of natural radioactivity in soil from Peshawar basin of Pakistan

Natural radioactivity in the environment may change with time due to human activities, chemical and biological changes. From the view of radiation risk to population, the knowledge of natural radioactivity levels and the measurement of collective radiation dose received by the population is very vital. Radiological constraints on soil of thickly populated Peshawar basin in northern Pakistan were assessed through radiometric assay. Soil samples collected from different locations of four districts of this basin were analysed using an HPGe gamma spectrometer. Activity concentrations of ⁴⁰K, ²²⁶Ra and ²³²Th in these samples was 648 ± 121 (421–996), 45 ± 7 (32–60) and 59 ± 7 (46–72) Bq kg^?1, respectively that followed lognormal distribution. The average concentrations of primordial radionuclides were found to be higher than that reported for the worldwide soil. Radium equivalent activity and gamma index derived from these activity concentrations were lesser than their respective limits. The average absorbed dose rate and the annual effective dose for both indoor and outdoor cases were found to be higher than the values given in the UNSCEAR 2000 report. The results of the present study were compared with those for other locations of Pakistan along with that for the world. The radiological impact of the measured data was evaluated using hazard assessment models. A thoughtful discussion of the above mentioned evaluation is also given.     

Evaluation of the natural radioactivity in food and soil around uranium mining region

Journal of Radioanalytical and Nuclear Chemistry - To evaluate the radiological risk to human health associated with the ingestion of radionuclides in foods, some different plant foods cultivated...     

Natural radioactivity in the soil samples in and around Kudankulam nuclear power plant site

The terrestrial gamma-radiation in soil and sand samples collected around Kudankulam nuclear power plant site, i.e., in Radhapuram Taluk of Tirunelveli District has been measured using NaI(T1) gamma-ray spectrometer. In the soil samples total dose due to three primordial radionuclides lies in the range of 13.1–168.2 nGy/h with a geometric mean of 137.2 nGy/h, which yields an annual effective dose of 0.17 mSv/y. In the sand samples the total dose due to three primordial radionuclides has been found to be in the range of 38.1–1964.4 nGy/h with a geometric mean of 300.8 nGy/h, which gives an annual effective dose of 0.37 mSv/y which is well below the permissible limit (1 mSv).     

Natural radioactivity levels and related risk assessment in soil samples from Sakarya,Turkey

Journal of Radioanalytical and Nuclear Chemistry - An evaluation of the environmental radioactivity levels in soil samples from Sakarya province (Turkey) was undertaken in order to create a...     

Assessment of soil radioactivity levels and radiation hazards in Guangyao Village,South China

Journal of Radioanalytical and Nuclear Chemistry - Single and binary titanium and silicon xerogels were prepared to evaluate and compare their sorption performance with commercial sorbents (Al2O3...     

Electrochemical determination of carbaryl oxidation in natural water and soil samples

An electrochemical method for the determination of carbaryl, after prior oxidation to 1,4-naphthoquinone in natural water and soils is reported. The coulometric oxidation of carbaryl at a platinum electrode was studied using 0.024 mol/L Britton-Robinson buffer (pH 7.0). The reduction of the oxidation product 1,4-naphthoquinone at a dropping mercury electrode was used for the indirect determination of carbaryl after separation on C₁₈ Sep-pak cartridges by differential pulse polarography (detection limits: 0.41 mg L^?1 of water and 0.47 mg kg^?1 of soil) and directly without separation by adsorptive stripping voltammetry (detection limits: 5 μg L^?1 of water and 7 μg kg^?1 of soil, for 75 s preconcentration time). Relative errors were lower than 3.7% and relative standard deviations smaller than 4.5%.