Activated carbon (AC) is widely used in various industries as an adsorbent material. It is used in gas cleaning industries, because of its low cost and high efficiency for removal of pollutants from effluents. It can be produced from a wide range of agricultural activities as by-products. There are different methods for producing the AC. The most common methods are physical and chemical activation that includes heat treatment, amination and impregnation. In this study, the effect of three impregnates, i.e., NaOH, KI and ZnCl ₂ on the quality of AC for ¹³¹ I removal, was investigated. Our results show that the sodium hydroxide impregnated AC is more effective for ¹³¹ I removal. Also, the quality of the impregnated AC was decreased in the case of impregnants material percentage exceeding 2%wt.

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Dosimetry studies pertaining to thermoluminescent dosimeter (TLD) and direct reading dosimeter (DRD) have been performed for photons, beta fields and mixed field of photons and beta particles. In lab conditions, for pure photon radiation fields, the doses estimated using DRD and TLD match within the acceptable limits whereas in the mixed fields of photons and high energy beta particles, it has been found that the DRD doses are always higher than the corresponding whole body doses estimated by the TLD. This is due to the fact that DRD responds to high energy beta particles and the typical response of the DRD to high energy beta particles is observed to be in the range of 15-30%. This may lead to TLD-DRD dose discrepancy at workplaces where the skin doses received by the radiation workers from high energy beta sources in a given monitoring period are significant. The paper also provides a comparison of three different TLD-DRD discrepancy identification criteria available in literature for exposure conditions with a significant dose due to beta radiations. In addition, estimate of threshold beta dose which may lead to discrepancy as per the criteria have been studied. The results reported in this paper would be helpful in understanding the discrepancy arising out of variable response of DRD to beta radiations and will be useful in resolving the discrepancy in such cases.

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Natural radioactivity of 30 granite rock samples collected from Alvand plutonic complex was determined using a high-resolution, high purity germanium gamma-spectrometry system. The activity concentrations of ²²⁶ Ra, ²³² Th and ⁴⁰ K varied from 8.4 ± 0.6 to 119.3 ± 1.9, i.e., minimum detectable activities (MDA) to 268.4 ± 3.3 and 62.9 ± 4.1 to 1602.6 ± 27.9 Bq/kg, respectively. ¹³⁷ Cs ranged from MDA to 4.9 ± 0.7 Bq/kg. The radium equivalent activity varies between 35.7 and 624.2 Bq/kg that is lower than the permitted value (370 Bq/kg) except in three samples. The absorbed dose rate ranged from 17.9 to 282.8 nGy/h, and the effective dose rate outdoor was determined to be between 21.9 and 347.0 μSv/y. The annual effective dose rate indoor varied from 87.8 to 1388.2 μSv/y that is lower than the dose criterion, 1 mSv/y, except for PGG(W) and GRG(W) samples. The internal and external hazard indices values range from 0.1-2.0 to 0.1-1.7, respectively, only four out of 30 showed values higher than unity.

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Globally, the cement industry has been identified as one which causes significant particle pollution. In Ghana, environmental research in the neighborhood of the cement industry especially on human health is scanty. In the present work, attempts were made to evaluate the concentration of airborne dust at various distances and directions around the Diamond Cement Factory in the Volta Region of Ghana. The samples of dust were collected on filter papers and later analyzed for the concentration (mg/kg) of ²³² Th and ²³⁸ U using neutron activation analysis. The principal objective of the study was to generate data intended at assessing the annual effective dose due to ²³² Th and ²³⁸ U inhalation for both adult and children population living in the vicinity of cement factory. The data generated were supposed to assist in remediation decision making, if required. The study recored a few incidences of higher total dust load concentrations as compared to the permissible limit of 150 μg/m ³ specified by the Ghana Environmental Protection Agency. The calculated mean effective doses were 28.2 ± 1.06 μSv/year and 25.9 ± 0.91 μSv/year for both adult and child, respectively. From the radiological point of view, the study concluded that the people living in the vicinity of the cement factory are not at risk to significant radiological hazards. However, the study indicated the need to have a complete evaluation of the impact of the factory on the environment assessment programs which should include both chemical and radiological toxicity.

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Radon activities and radon exhalation rates have been measured in soil samples collected from different location of Banda district of Uttar Pradesh in India using LR-115 type II solid state nuclear track detectors. Radon activity has been found to vary from (101.0) to (505.1) Bq/m ³ with an average value of (278.3) Bq/m ³ . Surface exhalation rate has been found to vary from (84.0) to (419.8) mBq/m ² /h with an average value (231.3) mBq/m ² /h, whereas mass exhalation rate has been found to vary from (2.1) mBq/kg/h to (10.6) mBq/kg/h with an average value of (5.8) mBq/kg/h. Effective dose from indoor inhalation exposure (radon) has been estimated, which is found to vary from (6.1) to (30.5) μSv/year with an average value of (16.8) μSv/year.

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Radon ( ²²² Rn) is a natural radioactive gas originating from U-238 series and is the decay product of radium-226, which occurs in rocks, soil, natural gas and ground water. Radon in air and domestic water supplies can cause human exposure to radiation dose both through inhalation and ingestion. Epidemiological studies have provided convincing evidence of an association between radon exposure and different types of cancer. The principal objective of this work was to determine the radon concentration in different water samples collected from the western desert of Egypt using alpha tracks method. The obtained results reveal that there is no significant public health risk from radon ingested with drinking water in the study region.

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A study was carried out in the Mumbai Harbour Bay sediment cores to measure concentration of biologically significant toxic elements such as Cr, Cu, Co, Ni, and Pb and to find out pattern of distribution in the sediment bed to follow the accumulation of elements with respect to depth. The range of concentration values of Cr, Cu, Co, Ni, and Pb in the sediment core fractions collected from three locations from Mumbai Harbour Bay sediment versus depth were plotted. Among the five elements, the concentration of Cr and Ni was found to be comparatively higher than all other elements with a range of 36 to 483 ppm and 24 to 155 ppm, respectively. The concentration of Co and Pb was observed to be lower in all the sediment cores and also evenly distributed in all the fractions with a range of 12-40 ppm and 10-270 ppm, respectively. Cu showed a range of 5-300 ppm.

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Radon, thoron and its (α-emitting) decay products contribute to more than 50% of the total effective dose due to natural background radiation. Hence, it is very important to simultaneously measure radon and their progeny concentrations in indoor environment to assess appropriate inhalation dose. In the present work, ²²² Rn (C_Rn ), ²²⁰ Rn (C_Tn ) and their progeny concentrations (EEC_Rn and EEC_Tn ) were measured inside the dwellings of Gogi region, Yadgir District, Karnataka, India. The dwellings were so chosen that they were within 5 km range from the uranium mining area. Measurements were carried out using passive detector systems: Pinhole dosimeters for radon and thoron; deposition based progeny sensors for radon and thoron progeny. The monitoring was carried out during April-July, 2013. The inhalation doses assessed from the measured gas and progeny concentrations in different type of dwellings were found to be within the permissible UNSCEAR limits.

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The results of uranium analyses in groundwater samples collected from areas adjacent to Turamdih and Jaduguda sites of solid waste disposal facilities (tailings pond) of process waste of the uranium industry are presented in the paper. These villages are within a distance of 0.5 km from tailings pond at either site. The concentration of uranium in approximately one-third of the samples was below the minimum detection limit (MDL) of 0.5 mg/m ³ . The highest uranium concentration of 16 mg/m ³ was found in tube well sample at the base of uranium mineralized hill of Turamdih with a median concentration of 0.95 mg/m ³ . Around tailings management facility at Jaduguda, the median concentration was 1.1 mg/m ³ with a maximum concentration of 10.9 mg/m ³ . The variations in monitoring results reflect the nature of uranium mineralization at the two sites. The results around Turamdih tailings pond show a high degree of asymmetry. Barring the MDL values, the lognormal distribution of uranium in groundwater around Jaduguda tailings pond was observed. The results reflect the natural distribution of uranium around the facility and contribution of tailings pond was not found in groundwater sources adjoining these facilities.

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Tiruchirappalli district has enriched resources of building materials such as stone, granite, sand, brick, cement, etc., which are also supplied to the neighboring districts. Since radon is considered as one of the causative factors for human lung diseases, the measurement of the radon level in these building materials is imperative for the assessment. The samples of building materials were collected from their original sources spread over Tiruchirappalli district. The sealed can technique with solid state nuclear track detector (SSNTD) was employed for the measurement of radon exhalation. The activity concentrations of radon in sedimentary rocks analyzed ranged from 13.2 Bq/m ³ to 218.0 Bq/m ³ with the geometric mean activity of 46.3 Bq/m ³ . However, radon concentrations in igneous rocks are distinctly higher than those of sedimentary rocks and ranged from 95.6 Bq/m ³ to 1140 Bq/m ³ with the geometric mean activity concentration of 392.6 Bq/m ³ . The radon exhalation from sand, brick, and cement were found to be non-uniform (sand: 119.8-656 Bq/m ³ , brick: 31-558 Bq/m ³ , cement: 172-300 Bq/m ³ ). The activity concentration of radon in these building materials follow a descending order: Granite > sand > cement > brick > sand stone. The mass and surface exhalation (E _M and E _A ) rates also follow the same order. The study concludes that since the radon exhalation from the building materials was less than the International Commission on Radiological Protection limit of 1500 Bq/m ³ , they do not pose any radiological risk.

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The screening based waste drum monitor system using neutron detectors was developed and evaluated. Present paper describes the studies carried out on the system evaluation for Plutonium Estimation. The system uses three BF ₃ neutron detectors with 3.8 cm HDPE moderator for two extreme detectors and with 7 cm HDPE moderator for middle detector arranged all three detectors in linear geometry. The middle detector shows less background and better sensitivity than of the two. Present system can detect 85 mg of plutonium at counting time of minimum1000 second or more. With changing the detectors geometry of the system to triangular geometry and replacing all the detectors with 7 cm moderator systems, performance as well as MDL can be improved.

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