A study to ascertain the radioactivity levels of various radionuclides from soil samples collected in Chad using a high-resolution gamma ray spectrometry system is presented in this article. The activity concentrations are determined for the radionuclides:²²⁶Ra,²¹⁴Pb,²¹⁴Bi and²²⁸Ac,²⁰⁸Tl,²¹²Pb following the decay of²³⁸U and²³²Th as well as⁴⁰K,²³⁵U, and¹³⁷Cs. The values of activity concentrations of²³⁸U,²³²Th, and⁴⁰K in the soil samples ranged from 2 to 245, 2–40, and 20–454 Bq/kg, whereas²³⁵U and¹³⁷Cs ranged from 0.8 to 21.7 and 0.3–3.8 (Bq/kg), respectively. In order to evaluate the radiological exposure of the natural radioactivity, the radium equivalent activity, external exposure index, internal exposure index, and annual effective-dose equivalent have been calculated which ranged from 27 to 465 (Bq/kg), 0.09–1.25, 0.13–2.38, and 0.09–1.65 (mSv/y), respectively. Correlation between²³⁸U versus²³²Th,⁴⁰K versus²³⁸U, and⁴⁰K versus²³²Th was investigated; the results showed good correlation for²³⁸U versus²³²Th and⁴⁰K versus²³⁸U while⁴⁰K versus²³²Th gives poor correlation. For the 20 samples collected and analyzed for this study, the results showed that average activity concentration of²³⁸U is relatively higher than the world average, while for both²³²Th and⁴⁰K, it was relatively lower.

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Thermoluminescent dosimeter (TLD) is still in use for many applications such as radiation protection, medical dosimetry, environmental research, and personnel dosimetry, with the overall aim of estimating radiation dose within a given medium or material. The aim of this study was to determine the coefficient of variation (CV) for thermoluminescent (TL) element within the same bar-coded slide and to establish calibration factors (CFs) at dose equivalent of 0.07 mm depth in tissue (Hp [0.07]) and dose equivalent of 10 mm depth in tissue (Hp [10]) for newly purchased TL elements alongside a new RadPro TLD manual reader and annealing oven. Annealed TL elements were taken to a Secondary Standard Dosimetry Laboratory (SSDL) for irradiation using a cesium-137 source at known doses (0.2–2 mGy). A RadPro Cube 400 manual TLD Reader was used to determine corresponding TL signal. The CV between two identical TL element within a bar-coded slide for (Hp [10]) and (Hp [0.07]) was determined and a graph of dose (mGy) against TL signal (Coulomb) was plotted to determine the elements CF. CVs from the raw data for 40 TL elements for Hp (10) and Hp (0.07) were 14.6% and 15.02%, respectively. Further selection of sensitive TL elements reduced the CVs of Hp (10) and Hp (0.07) to 3.73% and 3.21%, respectively, which was seen to be within ±10% accepted limit. The maximum percentage deviation for the calculated and actual dose for Hp (10) and Hp (0.07) was 16.7% and 14.3%, respectively. The CFs were power of 10 ^{− 6} and the Coefficient of determination (R²) for Hp (10) and Hp (0.07) was 0.9998 and 0.9981, respectively, after adjustments were made on the initial graphs. Although large deviations were observed at low doses from the results of the raw data. Re-selected “golden Chips” had R² close to unity and CV was within recommended standards.

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The objective of the present study is to propose a set of regional diagnostic reference levels (DRLs) for pediatric intraoral (IO) radiography procedures classified by IO examinations in Tamil Nadu, India. Of the 120 total units, 60 were digital and the remaining 60 units used film as image receptors. The third quartile values obtained for the selected IO examinations ranged from 1.05 mGy for the mandibular incisors to 1.48 mGy for the maxillary molars. The DRLs of the present study compare well with other International published DRLs. Following this primary study, DRLs will be proposed for other regions of the country, to arrive at national DRLs for pediatric IO dentistry.

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In the present investigation, the drinking water quality assessment in the water sources around china clay mine in Madayi Panchayath of Kannur District, Kerala, has been done. A study has been undertaken to understand, whether the quality of drinking water has any adverse effect from the mine which has been stopped mining for the last few years. The water samples were collected from ten randomly selected open wells around the china clay mine. The water quality parameters such as turbidity, pH, electrical conductivity, acidity, alkalinity, total dissolved solids, total hardness as (CaCO₃), and presence of calcium, magnesium, chloride, fluoride, iron, nitrate, ammonia, sulfate, and phosphate are identified and quantified following appropriate methods and techniques. The results obtained were compared with the permissible limit suggested by the Bureau of Indian Standards for drinking water specification (IS 10500: 2012). It is observed that, some of the open well samples have excessive hardness and alkalinity. This may be attributed to the wastes disposed from the china clay mine as the lands nearby this mining site are filled and leveled with these wastes. The prolonged consumption of water from these wells may cause various health disorders to the inhabitants. Hence, it is advised to process the water from such wells to reduce the hardness and alkalinity for safe consumption. In addition to this, in depth studies on heavy metal content of water are also needed to assess the quality of water sources in and around the china clay mine region, for the safe consumption.

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Reverse osmosis (RO) is a water purification process that uses a semi-permeable membrane to remove ions from potable water. It has high rejection throughput, low energy consumption, and negligible pollution load when compared to conventional treatment methods. Comparative percentage salt rejection (SR) efficiency for surrogates of cesium and molybdenum was performed using commercially available membranes. Polyamide, polysulfone, polyamide–polysulfone composite, and cellulose acetate were subjected to various operating conditions in a domestically developed high-pressure membrane test cell. Five different concentrations of surrogate salts ranging from 100 to 500 ppm and varied pressures of 15–17 kg/cm² combined with varying temperatures of the feed solution from 25°C to 45°C were used in this experimental work. It was found that the %SR efficiency of these membranes increased with the increase in salt concentration and feed temperature. However, a significant decrease in SR was observed with increasing pressure. A comparative study of these commercially available RO membranes was also performed against short-lived radioisotope Technetium-99m, and was determined by activity counts of feed and filtered samples using a well counter. The results suggest that the rejection efficiency was found to be highest in the case of polyamide–polysulfone composite, followed by polysulfone, polyamide, and cellulose acetate.

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World over there have been isolated cases of reported radiation emergencies, occurring at a very small probability. Environmental radiation mapping of vast area using mobile platforms is one of the methodologies used for quick radiological assessment. The utilization of several portable radiation monitoring instruments for mapping an area and the techniques developed are described. Design aspects of mobile monitoring vehicle for appropriate positioning of detectors and the speed of vehicle are optimized. The mobile radiological monitoring of cities help in quickly generating baseline data and data of a city is given in this paper. The utility of gamma spectrometer in a mobile monitoring vehicle are dealt in detail. The paper discusses various aspects of mobile monitoring, methodology, its application and representation on geographical information system under different situations.

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A study of natural radionuclides of different types of houses was conducted at 493 houses in the southern valley region of Manipur, India. The average annual effective doses of gamma radiation level in indoor and outdoor were estimated from the measurements using Micro R-survey meter and found as 1.25 ± 0.10 (range: 1.02–1.38) mSv/y and 0.76 ± 0.08 (range: 0.58–0.99) mSv/y for reinforced cement concrete (RCC) houses, followed by 1.07 ± 0.09 (range: 0.95–1.19) mSv/y and 0.76 ± 0.08 (range: 0.67–0.95) mSv/y for Adobe laid earthen houses, 1.05 ± 0.09 (range: 0.78–1.24) mSv/y and 0.74 ± 0.08 (range: 0.58–0.91) mSv/y for Assam-type (AT) brick houses, 0.83 ± 0.09 (range: 0.40–1.07) mSv/y and 0.72 ± 0.08 (range: 0.23–0.97) mSv/y for AT mud houses and 0.73 ± 0.08 (range: 0.66–0.82) mSv/y and 0.74 ± 0.07 (range: 0.64–0.82) mSv/y for AT katcha houses. The activity concentration²²⁶Ra,²³²Th, and⁴⁰K of building materials was evaluated using the gamma ray spectrometry and found average value as 42.4 (range: 23.0–69.9) Bq/kg, 111.3 (range: 23.8–214.5) Bq/kg, and 1369.0 (range: 995.7–2284.6) Bq/kg. Moreover, the annual effective dose conceived from the building material was found as 1.1 mSv/y from Portland cement, 1.4 mSv/y from sand, and 1.5 mSv/y from brick. Seasonal variations of indoor effective dose rates were observed in RCC houses; the highest dose rate was observed during the premonsoon season followed by postmonsoon and least with monsoon season.

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Chemical fertilizers, phosphate ore treatments, and phosphogypsum wastes contribute to enhanced levels of natural radionuclides in the environment. A total of 27 soil samples were collected from nine uncultivated sites around a Lebanese fertilizer plant in order to analyze the gamma emitter radionuclides (²³⁸U,²³²Th,²²⁶Ra,²¹⁰Pb,¹³⁷Cs, and⁴⁰K) and to assess the radiological impact on the surrounding environment, through the calculation of different radiological index parameters. In addition, a total of 27 Dittrichia viscosa plant samples were gathered including roots, leaves, and stems, and the radionuclide transfer factors were determined. Measurements were conducted using a gamma spectrometer with high-purity germanium detectors. The highest values measured in soil samples were 77 ± 9 Bq/kg, 102 ± 10 Bq/kg, and 143 ± 5 Bq/kg for²³⁸U,²²⁶Ra, and²¹⁰Pb, respectively.⁴⁰K levels were comparable to other Lebanese provinces and about 50% less than the worldwide average value. The results showed the absence of radionuclide transfer between soil and plants, except for⁴⁰K. The average values of the total absorbed dose rate and the annual effective dose were comparable to the worldwide average values. Therefore, the external exposure index and Radium equivalent were found to be below the international recommended values.

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