Assessment of natural radioactivity levels in soil samples from some areas in Assiut, Egypt

Distribution dynamics and descriptive statistical analysis of radionuclides in the farmland soils near mining areas in Southwestern Nigeria

Human exposure to ionizing radiation in the environment is mainly due to naturally occurring radionuclides in the soils, building materials and rocks, but the level may vary depending on the anthropogenic activities prevalent in each location. Presently, in Nigeria, there are concerns due to environmental health implications of all sorts of mineral mining and processing spreading across the southwestern states of the country. This work determines the activity concentrations of naturally occurring radionuclide materials (NORMs) in the farmland soil with the aim of evaluating the radiation hazards. A total of 200 composite soil samples were taken from five states in the southwest of Nigeria, close to active mining sites at the root (0.2 m) and at deep planting zones (0.5 m) for analysis by gamma-ray spectrometry using NaI(Tl) detector. The activity concentrations of natural radionuclides in the composite soil samples were determined to vary in the order of ⁴⁰ K > ²³²Th > ²²⁶Ra/²³⁸U for all locations. In contrast to the other locations, Olode and Igbokoda had average radium equivalent activities (Ra_eq) to be 1.6 and 1.8 times, respectively, higher than the reference limit of 370 Bqkg^-1. The estimated excess life cancer risk values were lower than the 0.29 × 10^-3 global average value for soil by United Nations on Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and International Commission on Radiological Protection (ICRP). Negative and low skewness values of 0.61 and 1.20 were obtained for ⁴⁰ K in Itagunmodi, and also 0.47 and 0.66 for ²³²Th were obtained in Sagamu. The kurtosis analysis of the activity concentrations was low and negative for soil at Itagunmodi for ⁴⁰ K and ²²⁶Ra/²³⁸U; Olode for ⁴⁰ K and ²³²Th; and Igbokoda for ²²⁶Ra/²³⁸U and ²³²Th where mining activities are commonly practiced. The variation in the results has been attributed to different agriculture practices and artisanal mining operations in each location.

Conceptualization of arid region radioecology strategies for agricultural ecosystems of the United Arab Emirates (UAE)

Since the last decade, ambitious nuclear power programmes have begun maturing in the Arab countries, most importantly in the United Arab Emirates (UAE). The region's environment and population, therefore, are prone to adverse, long-term impacts of radionuclide discharges. To calculate the associated exposure scenarios, to estimate doses and their consequences, and finally, to lay out a radiological emergency management plan, arid region radioecology is taking shape in the UAE as a major field of research. Geography, demography, food habits, weather, soil, water, flora, and fauna of the desert-marine regions are quite distinct from their temperate counterparts. This results in the need to increase the knowhows of environmental migration and bioaccumulation of radionuclides in the region's agricultural ecosystems. In this paper, we present a detailed review of the measured data from the UAE and nearby nations, generating insights for the soil radioactivity and soil-to-plant transfer phenomena under local arid conditions. In the literature, the radionuclide activity concentrations (in Bq kg^-1) vary over five orders of magnitude depending on nuclide type, sample type, and locality. Variabilities over six orders of magnitude are observed for transfer parameters too, and in-depth studies on the transfer mechanisms are usually scarce. We discuss the recent progresses made in root and foliar uptake studies with methods relatively new to sandy soils, like controlled potting, and soil K_d measurements. Showing the serious gaps in the data and interpretations, we provide a justification for the immediate experimentation in the understudied aspects of radioecology in the UAE and in arid lands in general.

Variations in growth behavior, yield and DNA stability of two vegetable crops cultivated in radioactive spiked soils

Radioactive pollution comes on the top of pollution types that affect human life directly through damaging the human genome or indirectly via his food web. The current study focused on the evaluation of radiation effects of Assiut Thermal Power Plant (ATPP) ashes on two crop plants, potato and squash, in terms of morphological and molecular levels. More particularly, the specific activity concentrations were measured in Bq/kg, of the ²³⁸U (²²⁶Ra) and ²³²Th series, and ⁴⁰K-isotope for the untreated soil sample (control) and ATPP ash sample (represents the radioactive source with 100% concentration). Different concentrations of ATPP ash (0, 2, 4, 6 and 8%) were mixed with soil sample to study the effect of radioactively contaminated soil on potato and squash plants. The results of the present investigation revealed that the morphological characteristics of both potato and squash plants were changed, which reflected a steep regression in the values of all vegetative growth and yield traits. The alterations of the characteristic values were directly proportional to the radioactive ash concentration in the soil. In the same context, the molecular evaluation using PCR-based markers, e.g., ISSR and SCoT helps in understanding and explaining experimental observations at morphological level. ISSR/SCoT bands confirmed the toxicity and mutagenicity of radioactive ash samples at their present dose on both potato and squash plants. The present findings clearly explained the morphometric and genetic abnormalities in two of the main consumed crops by a human. Thus, the green area around the ATPP may disappear in the future due to increasing the pollution in terms of the radioactive component that directly attached to plants or indirectly by mixing with soil.

Measurement of natural radioactivity in several sandy-loamy soil samples from Sijua, Dhanbad, India

The activity concentrations of natural radionuclides 226Ra, 232Th and 40K in soil samples collected from Sijua Dhanbad, India were measured by using a gamma-ray spectrometer with a NaI(Tl) detector. The average activity concentration of 226Ra, 232Th, and 40K was found as 60.3, 64.5 and 481.0 Bq .  kg - 1 , respectively. Average radium equivalent activity, absorbed dose rate, outdoor dose, external hazard index and internal hazard index for the area under study is determined as 189.5  Bq .  kg - 1 , 87.2nGy h - 1 , 0.4, 0.5 and 0.6 mSv .  y - 1 , respectively. The annual effective dose to the general public is found 0.4 mSv .  y - 1 . This value lies well below the limit of 1 mSv .  y - 1 . Measured values have found safe for the environment and public health of the study area.

Natural and anthropogenic radionuclides in urban soil around non-nuclear industries (Northern Al Jubail), Saudi Arabia: assessment of health risk

The residential areas are located around one of the oldest and largest non-nuclear industrial cities in Saudi Arabia, Arabian Gulf. Therefore, it is important to study the radioactivity levels in the urban soil in order to estimate the potential risk of radiation in environment and for public. The activity concentrations of ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs in urban soil around non-nuclear industries were measured using gamma ray spectrometric technique. The mean values of activity concentrations were found to be 7.64 ± 0.4, 3.76 ± 0.2, 174 ± 3.7, and 0.391 ± 0.03 (Bq/kg) for ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs, respectively. Radium equivalent activity (Ra_eq), gamma absorbed dose rate in air (D), and annual effective dose equivalent (E) for outdoor were calculated. The mean values of these radiological parameters were found to be less than the allowed limits in soil. The obtained results were compared with other studies from Arabian Gulf and other regions of the world. Consequently, the direct gamma radiation exposure from the urban soil in the study area was found to be safe for public. Additionally, the present study is the first in this area which could be used as a baseline for radioactivity levels in soil nearby industrial areas of the Arabian Gulf region.

Investigation of (235)U, (226)Ra, (232)Th, (40)K, (137)Cs, and heavy metal concentrations in Anzali international wetland using high-resolution gamma-ray spectrometry and atomic absorption spectroscopy

Measurements of natural radioactivity levels and heavy metals in sediment and soil samples of the Anzali international wetland were carried out by two HPGe-gamma ray spectrometry and atomic absorption spectroscopy techniques. The concentrations of (235)U, (226)Ra, (232)Th, (40)K, and (137)Cs in sediment samples ranged between 1.05 ± 0.51-5.81 ± 0.61, 18.06 ± 0.63-33.36 ± .0.34, 17.57 ± 0.38-45.84 ± 6.23, 371.88 ± 6.36-652.28 ± 11.60, and 0.43 ± 0.06-63.35 ± 0.94 Bq/kg, while in the soil samples they vary between 2.36-5.97, 22.71-38.37, 29.27-42.89, 472.66-533, and 1.05-9.60 Bq/kg for (235)U, (226)Ra, (232)Th, (40)K, and (137)Cs, respectively. Present results are compared with the available literature data and also with the world average values. The radium equivalent activity was well below the defined limit of 370 Bq/kg. The external hazard indices were found to be less than 1, indicating a low dose. Heavy metal concentrations were found to decrease in order as Fe > Mn > Sr > Zn > Cu > Cr > Ni > Pb > Co > Cd. These measurements will serve as background reference levels for the Anzali wetland.