Isotopes in Environmental and Health Studies最新文献

Environmental radioactivity is significantly elevated by coal combustion, posing risks to communities living near coal-fired thermal power plants (CFTPPs). This study presents the first comprehensive assessment of radiological impacts around the Rampal Thermal Power Plant, a 1320 MW facility located in Rampal Upazila, near the UNESCO World Heritage site of Sundarbans, Bangladesh. Thirty soil samples were systematically collected from distances of 100, 500, 1000, 2000, and 3000 m from the power plant. The activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K in soil ranged from 17-31, 29-51, and 350-670 Bq kg^-1, respectively, with a few samples exceeding the population-weighted global averages for ²²⁶Ra (32 Bq kg^-1) and ²³²Th (45 Bq kg^-1), and almost all the samples exceeding the average for ⁴⁰K (420 Bq kg^-1). The elevated levels of ²²⁶Ra, ²³²Th, and ⁴⁰K in the soil samples can be attributed to several interconnected factors, including the presence of thorium-rich minerals such as monazite and zircon, granitic geological formations, and anthropogenic inputs like bottom ash discharge from the plant and coal combustion byproducts. While the radium equivalent activity and hazard indices generally fell within safety limits, the higher outdoor and indoor absorbed dose rates, effective doses, and increased lifetime cancer risk raised alarms about potential health threats for nearby residents over time. Moreover, the long-term radiological effects on the Sundarbans ecosystem could disturb its fragile balance, impacting both biodiversity and the local communities that rely on its resources. These results highlight the necessity for further evaluations and remediation efforts to ensure the safe use of these soils in agricultural and construction activities. This research also seeks to develop a radiological distribution map, which will provide crucial baseline data for the forthcoming Rooppur Nuclear Power Plant.

In this paper, the results of indoor radon level measurements in thirteen single-family houses, on different floors, are presented. The measurement was performed using the AlphaE radon metre device, and in each house, the measurements lasted six days, on average. The mean values of the radon activity concentration were in the range of 32.32-525.65 and 18.41-185.25 Bq m^-3 for the ground floor and first floor rooms, respectively. The results of the statistical analyses on the variation of the radon level have shown that in nine houses (69 %), there is a significant difference in radon levels, with higher levels on the ground floor compared to the first floor. The variations of the radon levels during the night and daytime hours were also statistically analysed.

To assess the natural radioactivity levels and associated health risks in beach sand from Kuakata Sea Beach, this study performed a comprehensive radiological analysis of systematically collected sand samples using high-purity germanium (HPGe) γ-ray spectroscopy. The average (range) radioactivity levels of ²²⁶Ra, ²³²Th, and ⁴⁰K in the examined sand samples were 57 (37-105), 121 (76-231), and 210 (181-270) Bq kg^-1, respectively, thus markedly higher than the world average values of 30, 35, and 400 Bq kg^-1 for ²²⁶Ra, ²³²Th, and ⁴⁰K, respectively. The evaluation of different radiological risk parameters indicates values (maximum radium equivalent activity of 449.27 Bq kg^-1, maximum outdoor absorbed dose rate of 205.58 nGy h^-1, and maximum external hazard index of 1.21) much higher than the recommended levels, signifying that heavy minerals rich sands could pose a substantial health risk to individuals. The current findings have the potential to generate interest and exploration in rare-earth resources, particularly for their applications in the electronics industry, and thorium based nuclear fuel cycle resources for the next generation nuclear energy industry.

A survey on indoor radon, thoron and their progeny activity concentration has been carried out in two districts of Meghalaya, India, using the recently developed pin-hole dosimeter and DRPS/DTPS progeny sensors. Significant variation in these radionuclides has been observed amongst different house types and seasons of the year; responsible factors are discussed in detail. The mean observed concentration level of radon, thoron and their progeny are 63.7 ± 6, 65.1 ± 8, 24.8 ± 2 and 1.3 ± 0.1 Bq m^-3, respectively. These values are higher than the global average but lie within the prescribed limit. The estimated total annual effective dose is 2.07 mSv, which is within the permissible limit (3-10 mSv) as recommended by the International Commission on Radiological Protection (ICRP). Calculated values of radon and thoron equilibrium factors are, at par, with global findings. Positive but weak correlations between radon, thoron and their progeny concentrations have been observed.

The use of chemical and organic fertilizers in the farms of the Kurdistan region has increased because of land reclamation and agricultural activities. The ores used in some chemical fertilizers contain various amounts of radioisotopes such as ²³⁸U, ²³²Th, ⁴⁰K and ¹³⁷Cs. For this reason, chemical fertilizers are considered one of many sources of radionuclides and radioactivity in the environment. In this work, the specific activities of ²³⁸U, ²³²Th, ⁴⁰K and ¹³⁷Cs in samples of twenty common chemical fertilizers and of five organic fertilizers were estimated by using a gamma ray spectrometer based on the NaI(Tl) detector. The total average activity concentrations of ²³⁸U, ²³²Th, ⁴⁰K and ¹³⁷Cs were 8.81, 8.31, 2360.36 and 0.07 Bq kg^-1, respectively. In general, chemical fertilizers revealed higher radioactivity than organic fertilizers, and the agricultural application of these fertilizers may cause health risks unless their usage has been controlled scientifically.

This study aims to evaluate the radiation doses from building materials, including sand, cement, brick, faience, plaster and marble, collected from different sites in eastern Algeria. The specific activities of natural radionuclides, mainly represented by the natural radioactive series ²³⁸U, ²³²Th and primordial ⁴⁰K, were determined using a gamma spectrometry system equipped with a high purity germanium (HPGe) detector. Radiological hazard parameters (Ra_eq, H_ex, H_in, I_γ and I_α) associated with these activities were calculated to determine the suitability of the construction materials. To assess their radiological risks to human health, an analysis of absorbed dose rate (D), annual effective dose (AED) and excess lifetime cancer risk (ELCR) was performed and the results examined and compared with those reported elsewhere. The findings obtained for these samples are within the limits of internationally recommended values.

Over 50% of the annual dosage is caused by inhaling radon, thoron, and their decay products. Additionally, indoor concentrations of radon and thoron's decay agents are primarily responsible for the inhalation doses linked to these gases. This study aimed to measure the activity of radon in soil of Nizampur, and associated cancer risk using an RAD7 detector. The range and average values of radon in soil were found to be 994-14,700 Bq m^-3 and 6184 Bq m^-3, respectively. Radon exhalation rate ranged from 220 to 3442 Bq m^-2 h^-1 with an average value of 1447 Bq m^-2 h^-1. The statistical analysis of radon in the soil shows that due to possible localized sources or measurement inconsistency, ambient radon data often exhibits mild skewness or kurtosis, which is shown by minor deviations at the extremes (tails). Based on the values of radon exhalation rate which were found higher than the world permissible value of 57.60 Bq m^-2 h^-1, it is concluded that the soil of the study area may pose health hazards if it is used for construction or other purposes.

Online liquid chromatography (LC) followed by isotope ratio mass spectrometry (IRMS) is a trusted technique to detect honey adulteration based on the stable carbon isotope composition (δ¹³C) of trisaccharides, disaccharides, glucose and fructose. However, LC-IRMS demands specialised analytical setups not commonly found in most isotope labs. Here we investigate the use of off-line LC followed by elemental analysis (EA)-IRMS as an alternative employing more commonly available instruments. Precision and accuracy were excellent for fructose and glucose (error < 0.1 mUr), but less so for disaccharides and trisaccharides, which are similar results to online LC-IRMS. Therefore, offline LC-EA-IRMS can be a viable alternative for the analysis of honey purity employing stable carbon isotopes.

The pioneer work on the measurement and distribution of natural radioactivity levels was carried out in the sediment samples of Asia's largest coastal lagoon, Chilika, India. The activity concentrations of radionuclides in the sediment samples measured by using a high-resolution HPGe semiconductor detector gamma-ray spectroscopy system, and the average activity concentration of ²²⁶Ra, ²³²Th, and ⁴⁰K were found to be 28.25 ± 7.85, 84.27 ± 30.93 and 610.57 ± 89.74 Bq kg^-1. The contour map, drawn using the Kriging method, illustrates the geospatial distribution of each radionuclide in Chilika. The results show the distribution of radionuclides and are compared with similar results from different locations in the worldwide. The activity concentrations are also compared with the average values of the world and India. The radiological indices for the lagoonal system were calculated, and the mean values are 195.77 Bq kg^-1 for radium equivalent (Ra_eq), 167.53 nGy h^-1 for absorbed gamma dose rate (D_R), 0.21 mSv y^-1 for annual effective dose equivalent (AEDE), 631.27 µSv y^-1 for Annual gonadal dose equivalent (AGDE), 0.53 for external hazard index (H_ex), 0.61 for internal hazard index (H_in), 0.72 for gamma representative level index (Iγr), and 0.14 for alpha index (Iα). The mean value of the Ra_eq obtained from the study area was less than the international value of 370 Bq kg^-1. All the radiological assessment indices indicated that the observed values are below the threshold values.

Naturally occurring radioactive gases in soil, such as radon, are recognized for their significant impact on local air quality and potential health risks to nearby populations. The disturbance of the Earth's surface through excavation activities can enhance the release of these gases, increasing the likelihood of radon exposure. This study investigates soil samples collected from various sites across the Halabja governorate in Iraq to provide a comprehensive evaluation of the area's radiological profile. The primary objective is to measure alpha emitter concentrations of radon, radium and uranium present in the soil. Alpha particle tracks emitted from radon gas were recorded using a CR-39 detector. To enlarge and reveal the alpha tracks, the samples underwent chemical etching using a 6.25 N NaOH solution at 70 °C for seven hours, after which the tracks were analysed under a microscope. The findings demonstrate that alpha emitter concentrations of ²²²Rn, ²²⁶Ra and ²³⁸U ranged from 119.76 to 228.55 Bq/m³, 0.22 to 0.42 Bq/kg and 2.92 to 5.57 ppm, respectively. These results were within the safe limit. Radiological hazard parameters for indoor and outdoor (annual effective dose, excess lifetime cancer risk and effective dose rate to different body organs) were computed to assess the health risks associated with selected soil samples. The results of the study indicate that the levels of alpha-emitting radionuclides in the soil samples are below the recommended safety thresholds, suggesting that the surveyed area does not pose a radiological hazard. These findings offer important baseline data to support Iraqi public health initiatives and radon management strategies.