Transfer factors of 40K, 226Ra, 232Th from soil to different types of local vegetables, radiation hazard indices and their annual doses

Phytotoxicity of radionuclides: A review of sources, impacts and remediation strategies

Various anthropogenic activities and natural sources contribute to the presence of radioactive materials in the environment, posing a serious threat to phytotoxicity. Contamination of soil and water by radioactive isotopes degrades the environmental quality and biodiversity. They persist in soils for a considerable amount of time and disturb the fauna and flora of any affected area. Hence, their removal from the contaminated medium is inevitable to prevent their entry into the food chain and the organisms at higher levels of the food chain. Physicochemical methods for radioactive element remediation are effective; however, they are not eco-friendly, can be expensive and impractical for large-scale remediation. Contrastingly, different bioremediation approaches, such as phytoremediation using appropriate plant species for removing the radionuclides from the polluted sites, and microbe-based remediation, represent promising alternatives for cleanup. In this review, sources of radionuclides in soil as well as their hazardous impacts on plants are discussed. Moreover, various conventional physicochemical approaches used for remediation discussed in detail. Similarly, the effectiveness and superiority of various bioremediation approaches, such as phytoremediation and microbe-based remediation, over traditional approaches have been explained in detail. In the end, future perspectives related to enhancing the efficiency of the phytoremediation process have been elaborated.

Modeling and experimental assessment of naturally occurring radionuclides' transfer factors of orange fruits

The soil-to-orange fruit transfer factor of naturally occurring radionuclides was investigated. The temporal evolution of the three identified radionuclides, Ra-226, Th-232, and K-40, concentration was also examined throughout the growth period of the orange fruits until they reached maturity. A mathematical model was developed to predict the soil-to-fruit transfer of these radionuclides during the development of orange fruits. The results were found to agree with the experimental data. The experimental and modeling results revealed that the transfer factor for all radionuclides showed a similar exponential decline with the growth of the fruit and reached its minimum value when the fruit was ripe.

Radioactivity amounts, annual effective dose rate, and lifetime cancer risk estimation of some vegetable and fruit samples cultivated in Kahramanmaraş, Turkey

In this research, examples of the fruits and vegetables cultivated in Kahramanmaraş, ²³⁸U, ²³²Th, and ⁴⁰K levels, were detected, and in the case of consumption of these vegetables and fruits, for several age categories (adults, children (10 years old), and infants), annually effective dose rates and lifetime cancer risks were calculated. In fruit samples, concentrations of ²³⁸U, ²³²Th, and ⁴⁰K ranged from under detection limit (UDL) to 15.29 ± 1.14 Bq/kg, 0.30 ± 0.01 to 13.23 ± 1.60 Bq/kg, and 5.82 ± 0.21 to 179.82 ± 1.34 Bq/kg, respectively. The mean concentrations of ²³⁸U, ²³²Th, and ⁴⁰K in fruit samples were 5.31 ± 0.44 Bq/kg, 2.72 ± 0.26 Bq/kg, and 56.84 ± 0.57 Bq/kg, respectively. In vegetable samples, concentrations of ²³⁸U, ²³²Th, and ⁴⁰K ranged from 0.48 ± 0.04 to 11.77 ± 0.95 Bq/kg, 0.55 ± 0.04 to 4.57 ± 0.44 Bq/kg, and 9.32 ± 0.43 to 52.44 ± 0.52 Bq/kg, respectively. The mean concentrations of ²³⁸U, ²³²Th, and ⁴⁰K in the vegetable samples were 6.58 ± 0.65 Bq/kg, 2.72 ± 0.27 Bq/kg, and 27.09 ± 0.27 Bq/kg, respectively. The mean annual effective dose rates for adults, children (10 years old), and infants in fruit samples were 0.184 ± 0.001 mSv/y, 0.288 ± 0.002 mSv/y, and 0.304 ± 0.003 mSv/y, respectively. The average lifetime cancer risks for adults, children (10 years old), and infants in fruit samples were 0.647 ± 0.006 × 10^-4, 1.011 ± 0.010 × 10^-4, and 1.067 ± 0.010 × 10^-4, respectively. The mean annual effective dose rates for adults, children (10 years old), and infants in the vegetable samples were 0.118 ± 0.001 mSv/y, 0.128 ± 0.001 mSv/y, and 0.086 ± 0.001 mSv/y, respectively. The mean lifetime cancer risks for adults, children (10 years old), and infants in vegetable samples were 0.416 ± 0.004 × 10^-4, 0.449 ± 0.004 × 10^-4, and 0.304 ± 0.003 × 10^-4, respectively.

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.

The plant transfer factor of natural radionuclides and the soil radiation hazard of some crops

In the present study, the transfer factors of the natural radionuclides ²³⁸U, ²³²Th, and ⁴⁰K were estimated for several crops cultivated in farms in the suburbs of Baghdad and one farm in Al-Najaf. The transfer factor (T_F) is the ratio of activity transfers from soil to plant. The specific activities of the natural radionuclides were measured with a gamma-ray spectrometer with a HPGe detector. The crops include cereals (rice and wheat), fruits (lemons and oranges), podded vegetables (vigna and okra), fruity vegetables (chili peppers and Solanum melongena), and leafy vegetables (Apium graveolens, Raphanus sativus, and Ocimum basilicum). The results showed that the highest transfer factors for ²³⁸U, ²³²Th, and ⁴⁰K are 0.32, 0.70, and 3.44, respectively, in wheat. The average transfer factors for ²³⁸U and ²³²Th were founded 0.23 and 0.2 which are lower than the default unitiy value but the 1.85 were reported for ⁴⁰K higher than unity.

SOIL-SOYBEAN TRANSFER FACTOR OF NATURAL RADIONUCLIDES IN DIFFERENT SOIL TEXTURES AND THE ASSESSMENT OF COMMITTED EFFECTIVE DOSE

From three different soil textures (clay, silt and sand), 36 soil and soybeans samples were accumulated from the agricultural area of EL-Mynia governorate in Upper Egypt, between (27°36'19.44″N; 30°30'14.14″ E) and (28°48'28.45″ N; 31°00'32.27″ E). Soil textures were prepared by particle size distribution through a pipette method. Its radioactivity measurements were performed with a NaI (Tl) and 3 × 3 inch crystal. The transfer factor (TF) of natural radionuclides from soil to soybeans was calculated. The value of the TF for 226Ra in clay soil ranges from 0.27 ± 0.03 to 0.42 ± 0.05, in sandy soil it ranges from 0.21 ± 0.02 to 0.57 ± 0.07 and in silt soil it ranges from 0.25 ± 0.03 to 0.53 ± 0.06. The TF for 232Th in clay soil ranges from 0.22 ± 0.03 to 0.90 ± 0.12, in sandy soil it ranges from 0.21 ± 0.03 to 1.00 ± 0.13, while in silt soil it ranges from 0.25 ± 0.03 to 0.88 ± 0.12. The TF for 40K in clay soil ranges from 0.95 ± 0.13 to 2.05 ± 0.29, in sandy soil it ranges from 1.21 ± 0.17 to 2.52 ± 0.35 and in silt soil it ranges and from 1.01 ± 0.14 to 1.46 ± 0.26.The results show that the committed effective dose from soybean consumption is between 54.5 and 103.4 μSv y-1 assuming consumption of 20 kg y-1.

A REVIEW ON 210Po AND 210Pb IN INDIAN SEAFOOD AND DOSE TO CONSUMERS

India is the second largest seafood producer in the world marketing more than 7000 edible species. In this regard, commendable studies have been conducted since the 1970s by different research groups and more data are reported. In this work, all the studies on 210Po and 210Pb measurements in abiotic and biotic components of India have been combined and reviewed. The concentrations of 210Po and 210Pb are estimated by radiochemical separation followed by alpha counting. Grain size, season, Tsunami waves and place of sampling have a decisive bearing on 210Po and 210Pb concentration in abiotic components. Plankton shows a higher Kd factor (104) compared to seaweeds and sea grass (103). Pond ecosystems recorded the highest Kd factor (4·3 × 104) compared to other freshwater and marine ecosystems. Bioaccumulation of 210Po and 210Pb varies with respect to variety of seafood. The committed effective dose (CED) calculated for shellfish species maintained a higher range of 2.5 × 10-2 mSv/y to 9.8 × 10-1 mSv/y and for fish species fluctuated from 3.8 × 10-4 mSv/y to 2.0 × 10-1 mSv/y. The studies conducted so far are scattered, and need to be gathered for future reference and planning (i.e. There is not much information available for Kerala, Karnataka, Maharashtra, Gujarat, Andhra, West Bengal and Odessa coast). Therefore, it is strongly recommended that further and more complete research is undertaken to study the bioaccumulation of 210Po and 210Pb from seafood. Overall, the present review concludes that Indian seafood is radiologically safe.