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Uptake of uranium by vegetables and rice
Abstract
The uptake of U by vegetables from soil and water has been studied in pots by spiking the soil and the irrigation water with U. An increase in the U level in vegetables has been observed with an increase of U content in the irrigation water and not with soil U. However, the concentration factor for the uptake of U by vegetables decreases with increase of U in water. The study of distribution of U in rice (Oryza saliva) indicates the discrimination of U by different parts of the crop. Among root, stem, and grain, the lowest concentration of U has been observed in grain (rice).
... Uranium uptake by plants from the soil and its translocation within the plant was found to vary depending on plant species (Gulati et al., 1980;Lakshmanan & Venkateswarlu, 1988;Schnug et al., 1996;Whicker et al., 1999). Very few is known about the responsible mechanisms. ...
... U uptake by plants increases with the increase of U in the soil or irrigation water (Lakshmanan & Venkateswarlu, 1988;Singh, 1997). Some species have developed the ability to tolerate high concentration of heavy metals like uranium. ...
... In all cases dU content in plant increased with higher values of U in soils or water which was in agreement with results reported by Lakshmanan and Venkateswarlu (1988), and Singh (1997). ...
Depleted Uranium (dU) is usually used in the weapon to increase its destruction power inflected to the target. Therefore, this study was conducted to detrmine the effect of of a range of dU concentration in the soil an incident of the desrruction of military tank in southern part of Iraq on radioisotope content in soil and in tomato plant grown in the area. The dU concentration in the incident spots located in Safwan destrict close to Jabel Sanam, north of Rumala oil field was 4000 mg Kg-1 in the soil. The soil also was found to contain a considerable level of 234Th, 226Ra and 40K. Tomato growth was reduced with the increase of dU concentration compared to those grown in same soil of no dU content. It even has failed to grow in the soil with high level of dU. Tomato plant uptake of 238U as determined by radioactivity of its direct daughter 234Th was found to increase with the increase of dU concentration in soil. The dU concentration higher than 500 mg kg-1 soil was lethal to tomato plant.
... These cardinal considerations stress that there is no general relationship between radionuclide in plant and soil as the definition of transfer factors implies (Ehlken and Kirchner 2002). Concentration factors were about 10 times higher when vegetable plants were grown on a farm soil (2.1 mg kg -1 U) than on a spiked soil (21.3 mg kg -1 U; Lakshmanan and Venkateswarlu 1988). The discrepancy was even stronger when U was added by irrigation water as the concentration factor was more than 30 times higher when unpolluted water was used. ...
... A high soil moisture regime caused obviously a higher solubility of DU and thus plant availability ) and this finding confirms results obtained by Lakshmanan and Venkateswarlu (1988). provide a comprehensive overview of concentration ratios found in literature for different grass species. ...
... Index of tolerance (%) = (biomass U-treatment / biomass control ) * 100 2 Bioaccumulation coefficient = U plant / U soil (total) (1) Chen et al. (2005): Impact of mycorrhiza at highest P level in wild type barley plants; (2) Rivas (2005); (3) Meyer et al. (2004) ; a U as DU; (4) Shahandeh and Hossner (2002); (5) Chang et al. (1995); b Values after citric acid treatment; (6)Lakshmanan and Venkateswarlu (1988); c Irrigation with water containing 368 µg L -1 U; (7)Ebbs et al. (1998): *100, d without/with citric acid treatment; (8)Butnik and Ischenko (1989); e U in straw/chaff/grain in field experiment. ...
Sustainable development is development that meets the needs of the present withoutcompromising the ability of future generations to meet their own needs”. One importantaspect of sustainable development in agriculture is the responsible management ofnatural resources of which soils and water bodies are the most endangered ones. Amajor threat for soils are loads with toxic heavy metals applied unintentionally withfertilizers and which accumulate and may pass through soils into ground and surfacewaters. Any agricultural system where the input of heavy metals exceeds the sum ofremoval by crops and unavoidable losses to the environment is in fact non-sustainablebecause it leaves a burden for further generations. One of the most dangerous heavymetals is uranium, because it is not only bio-chemically toxic but also radioactive.Uranium is dispersed in significant amounts for instance via phosphorus fertilizers.Although a lot of uranium research has been done under many viewpoints, theagricultural aspect and its environmental impact has not been paid much attention so far.
(21) (PDF) Loads and Fate of Fertilizer-derived Uranium. Available from: https://www.researchgate.net/publication/236987016_Loads_and_Fate_of_Fertilizer-derived_Uranium [accessed Feb 10 2024].
... These results are in disagreement with those obtained by Kovalevsky (IAEA 1985); since this author stated that U absorption by plants was, on average, 3,000 times more vigorous from aqueous solutions than from the soil. Despite different study conditions, other authors (Lakshmanan and Venkateswarlu 1988;Hakonson-Hayes et al. 2002) also observed an increase in the U level in vegetables with the increase of U concentration in the irrigation water. ...
... However, for the same soil both W-BCs (BC plant/water and BC leaf/water ) were higher in the plot watered with lower uranium concentration, as is the case of soil C (Table 3). Lakshmanan and Venkateswarlu (1988) also observed that the concentration factor for the U uptake by vegetables decreases with water U increase. The uranium chemical species present in the different irrigation waters might explain these results. ...
Past uranium mining in the area of Cunha Baixa village, near Mangualde (Portugal), led to contamination of subsurface waters used for irrigation in the agricultural area of this village. To test radionuclide transfer to plants, two side-by-side parcels of land, each divided into four replicate lots, were used for experimental growth of potatoes (Solanum tuberosum L.). One parcel of land was irrigated with water containing a high uranium concentration (13.7 Bq1-1) and the other was irrigated with water containing a low uranium concentration (0.3 Bq1-1). Agricultural procedures were controlled and radionuclide concentrations in soil and irrigation water were measured. The potato crop was collected and samples with and f 238 235 234without peel were analysed or uranium isotopes (238U, 230U, 234U) and uranium series (238U daughters) alpha-emitting radionuclides (i.e. 230Th, 226Ra, 210Po). The results show a significant uptake of radium, reaching 12.9 ±1.2 Bq kg dry weight, and a minor uptake of other radionuclides by potatoes. Radium transfer to potatoes was enhanced in the parcel of land irrigated with water containing high radium concentrations, but radionuclide concentrations in irrigation water had a minor effect on the transfer of uranium, thorium and polonium to potatoes. Radionuclides were largely accumulated in tubers' peel and, in general, peeling removed most of the radioactivity. As radium in irrigation water was found to be accumulated in potatoes it may be transferred to man through the food chain. Therefore, this radionuclide should be monitored in agricultural zones near uranium mine areas.
... These results are in disagreement with those obtained by Kovalevsky (IAEA 1985); since this author stated that U absorption by plants was, on average, 3,000 times more vigorous from aqueous solutions than from the soil. Despite different study conditions, other authors (Lakshmanan and Venkateswarlu 1988;Hakonson-Hayes et al. 2002) also observed an increase in the U level in vegetables with the increase of U concentration in the irrigation water. ...
... However, for the same soil both W-BCs (BC plant/water and BC leaf/water ) were higher in the plot watered with lower uranium concentration, as is the case of soil C (Table 3). Lakshmanan and Venkateswarlu (1988) also observed that the concentration factor for the U uptake by vegetables decreases with water U increase. The uranium chemical species present in the different irrigation waters might explain these results. ...
Uranium mining activity in Cunha Baixa (Portugal) village has left a legacy of polluted soils and irrigation water. A controlled
field experiment was conducted with lettuce (Lactuca sativa L.) in an agricultural area nearby the abandoned mine in order to evaluate uranium uptake and distribution in roots and leaves
as well as ascertain levels of uranium intake by the local inhabitants from plant consuming. Two soils with different average
uranium content (38 and 106mg/kg) were irrigated with non-contaminated and uranium contaminated water (<20 and >100μg/l).
A non-contaminated soil irrigated with local tap water (<1μg/l uranium) was also used as a control. Uranium in lettuce tissues
was positively correlated with soil uranium content, but non-significant differences were obtained from contaminated soils
irrigated with different water quality. Uranium in plants (dry weight) growing in contaminated soils ranged from 0.95 to 6mg/kg
in roots and 0.32 to 2.6mg/kg in leaves. Lettuce bioconcentration is more related to available uranium species in water than
to its uranium concentration. Translocated uranium to lettuce leaves corresponds to 30% of the uranium uptake whatever the
soil or irrigation water quality. A maximum uranium daily intake of 0.06 to 0.12μg/kg bodyweight day was estimated for an
adult assuming 30 to 60g/day of lettuce is consumed. Although this value accounts for only 10% to 20% of the recommended
Tolerable Daily Intake for ingested uranium, it still provides an additional source of the element in the local inhabitants’
diet.
... However the U content on tubers grown in soil plots A or B irrigated with CW and NCW was not significantly different. According to Lakshmanan and Venkateswarlu (1988), U content in plants increases proportionally with the U concentration in soils. These authors also reported that for the same soil, the U concentration in plants increased with the U concentration in irrigation water. ...
... The average concentrations of U in potato tubers (70 μg U/kg DW) grown in soils from the Kalna-Gabrovnica U mine (Serbia) (Sarić et al., 1997) are 4 to 11-fold lower than those detected in this study for tubers from soil plots B. Also, Lakshmanan and Venkateswarlu (1988) found that in potatoes grown in pots with red sandy soil and irrigated with U rich water (368 μg U/L), had lower U concentrations (38.88± 3.75 μg U/kg FW) than tubers from soil plots B (BCW: 110.5 ± 26.0 μg U/kg FW; BNCW: 56.8±19.2 μg U/kg FW). ...
Knowledge about metals in crops, grown in contaminated soils around mine sites, is limited and concerns about exposure to hazardous elements through the consumption of contaminated foodstuff, are high. In this study a field experiment was carried out in two agricultural soils located near a former uranium mine area (Cunha Baixa, Portugal). The purpose of the study was to assess the effect of irrigation water quality on soil-potato (Solanum tuberosum L.) crop system and to evaluate if the consumption of the crop represents health risk to the local villagers. The soils were divided in two plots: one irrigated with contaminated water (U: 1.03-1.04mg/L; Al: 7.5-8.00mg/L; Mn: 4.52mg/L) and the other with uncontaminated water (U: 14-10μg/L; Al: 17-23μg/L; Mn: 2.4-5.7μg/L). After irrigation and potato growth, only soil characteristics, as salinity and total U and Mn concentrations were significantly different from those measured at the beginning of the experiment. Within the potato plants, elements were mostly translocated and concentrated in the aerial part: stems and leaves (U: 73-87%; Al: 85-96%; Mn: 85-94%), which minimize the risk of contamination of the edible tissue. In potato tubers, the highest average concentrations (121-590μg U/kg; 25-64mg Al/kg; 12-13mg Mn/kg dry weight) were registered at soil plots irrigated with contaminated water. Uranium and Al were mostly concentrated in the potato peel (88-96 and 76-85%, respectively), and Mn (67-78%) in the pulp, which reinforces the importance of removing peel to minimize human exposure. The risk analysis calculated for non-cancer health effects (hazard quotient), related only to the exposure through the consumption of this basic foodstuff, revealed safety for Cunha Baixa village residents (adults and children) even when potato crop was grown on U enriched soils and irrigated with contaminated water.
... In the taxonomic context of crops, U concentration in Lactuca sativa demonstrated notable variations, with the Romana variety exhibiting higher accumulation and retention in the roots, while the Marady variety showed increased accumulation in the leaves [50]. When comparing the recommended limit of 11.7 ppm set by UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation), the regions of Canada and Portugal exhibited the highest levels of U accumulation, particularly in RDH and LTT, with concentrations ranging from 3 to 14 mg/kg [51][52][53]. ...
Uranium (U) and fluoride (F⁻) contamination in agricultural products, especially vegetable and cereal crops, has raised serious concerns about food safety and human health on a global scale. To date, numerous studies have reported U and F⁻ contamination in vegetable and cereal crops at local scales, but the available information is dispersed, and crop-wise differences are lacking. This paper reviews the current status of knowledge on this subject by compiling relevant published literatures between 1983 and 2023 using databases such as Scopus, PubMed, Medline, ScienceDirect, and Google Scholar. Based on the median values, F⁻ levels ranged from 0.5 to 177 mg/kg, with higher concentrations in non-leafy vegetables, such as Indian squash “Praecitrullus fistulosus” (177 mg/kg) and cucumber “Cucumis sativus” (96.25 mg/kg). For leafy vegetables, the maximum levels were recorded in bathua “Chenopodium album” (72.01 mg/kg) and mint “Mentha arvensis” (44.34 mg/kg), where more than 50% of the vegetable varieties had concentrations of >4 mg/kg. The concentration of U ranged from 0.01 to 17.28 mg/kg; tubers and peels of non-leafy vegetables, particularly radishes “Raphanus sativus” (1.15 mg/kg) and cucumber “Cucumis sativus” (0.42 mg/kg), contained higher levels. These crops have the potential to form organometallic complexes with U, resulting in more severe threats to human health. For cereal crops (based on median values), the maximum F⁻ level was found in bajra “Pennisetum glaucum” (15.18 mg/kg), followed by chana “Cicer arietinum” (7.8 mg/kg) and split green gram “Vigna mungo” (4.14 mg/kg), while the maximum accumulation of U was recorded for barley “Hordeum vulgare” (2.89 mg/kg), followed by split green gram “Vigna mungo” (0.45 mg/kg). There are significant differences in U and F⁻ concentrations in either crop type based on individual studies or countries. These differences can be explained mainly due to changes in geogenic and anthropogenic factors, thereby making policy decisions related to health and intake difficult at even small spatial scales. Methodologies for comprehensive regional—or larger—policy scales will require further research and should include strategies to restrict crop intake in specified “hot spots”.
... Previous studies on different species showed that U mainly accumulates in the roots (Laroche et al. 2005;Doustaly et al. 2014). Other studies observed differences between U distributions in upper organs (Lakshmanan and Venkateswarlu 1988;Singh 1997). Exposure to U can cause physiological, biochemical and molecular damage to plants. ...
Environmental contamination by uranium (U) and other radionuclides is a serious problem worldwide, especially due to, e.g. mining activities. Ultimate accumulation of released U in aquatic systems and soils represent an escalating problem for all living organisms. In order to investigate U uptake and its toxic effects on Pisum sativum L., pea plantlets were hydroponically grown and treated with different concentrations of U. Five days after exposure to 25 and 50 μM U, P. sativum roots accumulated 2327.5 and 5559.16 mg kg−1 of U, respectively, while in shoots concentrations were 11.16 and 12.16 mg kg−1, respectively. Plants exposed to both U concentrations showed reduced biomass of shoots and reduced content of photosynthetic pigments (total chlorophyll and carotenoids) relative to control. As a biomarker of oxidative stress, lipid peroxidation (LPO) levels were determined, while antioxidative response was determined by catalase (CAT) and glutathione reductase (GR) activities as well as cysteine (Cys) and non-protein thiol (NP-SH) concentrations, both in roots and shoots. Both U treatments significantly increased LPO levels in roots and shoots, with the highest level recorded at 50 μM U, 50.38% in shoots and 59.9% in roots relative to control. U treatment reduced GR activity in shoots, while CAT activity was increased only in roots upon treatment with 25 μM U. In pea roots, cysteine content was significantly increased upon treatment with both U concentrations, for 19.8 and 25.5%, respectively, compared to control plants, while NP-SH content was not affected by the applied U. This study showed significant impact of U on biomass production and biochemical markers of phytotoxicity in P. sativum, indicating presence of oxidative stress and cellular redox imbalance in roots and shoots. Obtained tissue-specific response to U treatment showed higher sensitivity of shoots compared to roots. Much higher accumulation of U in pea roots compared to shoots implies potential role of this species in phytoremediation process.
... Lindahl et al. (2011) reported that 226 Ra is preferably retained in the roots compared with the aboveground plant parts. Lakshmanan and Venkateswarlu (1988) also observed the lowest radionuclide concentration in the grains. Similarly, the maximum distribution of 232 Th was found in the root (57%) and the minimum was in the grain (8%) (Fig. 4). ...
... Lindahl et al. (2011) reported that 226 Ra is preferably retained in the roots compared with the aboveground plant parts. Lakshmanan and Venkateswarlu (1988) also observed the lowest radionuclide concentration in the grains. Similarly, the maximum distribution of 232 Th was found in the root (57%) and the minimum was in the grain (8%) (Fig. 4). ...
Radioactivity distribution and transfer factor (TF) in plants are crucial parameters used to assess radioactive contamination in the environment and its risks to humans. In this study, the activities of 226Ra, 232Th, and 40K were successfully measured via gamma-ray spectrometry on rice plant components (root, straw, husk, and grain) and on corresponding soil samples collected from paddy fields in Penang, Malaysia. Soil physico-chemical characteristics (pH, cation exchange capacity, electrical conductivity, organic matter, and soil texture) were also analyzed for their estimated effects on soil–grain TF. A major fraction of the total 226Ra and 232Th activities measured as 47% and 57%, respectively, were concentrated in the roots, whereas only about 9% and 8% were distributed in the grains, correspondingly. 40K activity accumulation was about 59% in the straw and 7% in the grains. Rice soil–grain TFs were observed in the ranges of (0.06–0.36) × 10−1 for 226Ra, (0.04–0.14) × 10−1 for 232Th, and (0.74–4.72) × 10−1 for 40K. Results showed that the selected radionuclide distributions in rice are dependent on component type, and their grain concentrations are not linearly related to their soil concentrations. These findings indicated that uptake predominantly depends on soil physico-chemical characteristics.
... A mesma tendência foi observada para a folha da alface (tabela 2). Alguns autores verificaram, pelo contrário, que para um mesmo solo, o teor de urânio nas plantas tende a aumentar com o enriquecimento do elemento na água (Gulati et al. 1980; Lakshmanan e Venkateswarlu 1988; Hakonson-Hayes et al. 2002). ...
... Lindahl et al. (2011) reported that 226 Ra is preferably retained in the roots compared with the aboveground plant parts. Lakshmanan and Venkateswarlu (1988) also observed the lowest radionuclide concentration 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 in the grains. Similarly, the maximum distribution of 232 Th was found in the root (57%) and the minimum was in the grain (8%) (Fig. 3). ...
Radioactivity distribution and transfer factor (TF) in plants are crucial parameters used to assess radioactive contamination in the environment and its risks to humans. In this study, the activities of 226Ra, 232Th, and 40K were successfully measured via gamma-ray spectrometry on rice plant components (root, straw, husk, and grain) and on corresponding soil samples collected from paddy fields in Penang, Malaysia. Soil physico-chemical characteristics (pH, citation exchange capacity, electrical conductivity, organic matter, and soil texture) were also analyzed for their estimated effects on soil–grain TF. A major fraction of the total 226Ra and 232Th activities measured at 47% and 57%, respectively, were concentrated in the roots, whereas only about 9% and 8% were distributed in the grains, correspondingly. 40K activity accumulation was about 59% in the straw and 7% in the grains. Rice soil–grain TFs were observed in the ranges of (0.06–0.36) × 10−1 for 226Ra, (0.04–0.14) × 10−1 for 232Th, and (0.74–4.72) × 10−1 for 40K. Results showed that the selected radionuclide distributions in rice are dependent on component type, and their grain concentrations are not linearly related to their soil concentrations. These findings indicated that uptake predominantly depends on soil physico-chemical characteristics.
... The transfer factors obtained are in good agreement with literature data, taking into consideration the fact that transfer factors usually vary over a wide range as well as that the transfer factors of natural radionuclides for agricultural products are generally low. There are several reports that, among agricultural products, leafy vegetables generally show higher transfer factors, followed by root, fruit and grain crops [1,5,6]. ...
This paper deals with industrial tailings resulting from the use of radioactive coal and bauxite for assessing the impact on the population and the environment in the western Balkan countries (WBC). It considers the direct hazard resulting from the wastes for their immediate neighbourhood and the radionuclide dispersal in the environment through surface and groundwater. The selected test sites have been investigated by different methods assessing the presence and type of radionuclides in the primary and waste products, analyzing and identifying the pathways for dispersion of radionuclides in the waste surroundings, and defining the impact of the waste on the ecosystem. The process of leachability and fractionation of the different radionuclides has been studied, too. The transport of radionuclides in groundwater has been studied by 3D groundwater flow and solute transport modelling. The following parameters have been assessed (1) gamma dose-rate levels (2) radon in soil gas (3) radon exhalation (4) indoor and outdoor radon (5) radionuclide activity in soil and in waste material (6) radionuclides in surface water and groundwater (7) radionuclides in biota. Several case studies highlight the transfer of the radionuclides to plants and animal consumption products. The radionuclide concentrations in the waste and in the surroundings range over three orders of magnitude. Radionuclide concentrations in groundwater surrounding the waste are low and have a lower variability than in the wastes. Radon concentrations on the tailings are increased with respect to the surroundings. The transfer factors in the soil–plant–animal system indicate low bioavailability of investigated radionuclides. A preliminary dose assessment shows that the highest contribution to dose is from external and radon exposure. On the basis of the results obtained by using transport model simulation and considering the high Kd values and low concentration of radium, radionuclide transport in groundwater is slow and limited to a restricted area around the tailings sites.
... Among the vegetable foodstuffs studied, apple with peel and maize (grain) presented the lowest uranium concentration (11 and 22 lg/kg DW, respectively), even though each was watered with uranium-contaminated water (218 lg/l) and had the highest uranium available fraction in the soil (32.9 mg/kg). These results agree with those reported by several researchers who reported that fruit and grains, in general, store less uranium than leaves or roots (Lakshmanan and Venkateswarlu 1988;Choudhury et al. 1992;Shahandeh and Hossner 2002;EFSA 2009). In fact, in many plant species, the roots act as a barrier that prevents the transport of many elements, including radionuclides to the upper parts of the plant (Shtangeeva 2008). ...
Large uranium accumulations in vegetable foodstuffs may present risks of human health if they are consumed. The objective of this study was to evaluate the uranium concentrations in different vegetable foodstuffs and grown in agricultural soils, which are then consumed by the residents of the village of Cunha Baixa (Portugal),—located in an former uranium mining area. This study was conducted to address concerns expressed by the local farmers as well as to provide data for uranium-related health risk assessments for the area. Soils, irrigation water and edible tissues of lettuce, potato, green bean, carrot, cabbage, apple and maize (Latuca sativa L., Solanum tuberosum L., Phaseolus vulgaris L., Daucus carota L., Brassica oleracea L., Malus
domestica Borkh, Zea mays L., respectively) were sampled and uranium determined. High uranium concentrations were found in some soils (Utotal > 50 mg/kg), in irrigation waters (218 to 1,035 μg/l) and in some vegetable foodstuffs (up to 234, 110, 30, 26, 22, 16 and 1.6 μg/kg fresh weight for lettuce, potato with peel, green bean pods, cabbage, corn, carrot and apple, respectively). However, the results of the toxicity hazard analysis were reassuring the estimated level of uranium exposure through the ingestion of these vegetable foodstuffs was low, suggesting no chemical health risk (hazard quotient <1) to this uranium exposure pathway for a local residents during their lifetime, even for the most sensitive part of the population (child).
... Uptake of U by vegetables and rice has shown lesser accumulation in former with increase in concentration of U in irrigating water but with no effect of U in soil. Again there was differential accumulation of U in Rice plant with least accumulation in grain [10] . Metal levels in sugar cane (Saccharum spp.) samples from areas under the influence of municipal landfill and medical waste treatment system also showed indications of increased metal content in edible tissues of sugar cane [11] . ...
East Calcutta Wetland (ECW) is an example of wise use of cities solid and liquid waste through integrated resource recovery, mainly for pisciculture, vegetable as well as paddy cultivation and manure production. Amaranthus caudatus, Amaranthus blithum and Spinacia oleracea grown at ECW were analyzed for their accumulation of elements using Energy Dispersive X Ray Fluorescence (EDXRF) and compared to those grown in south eastern parts of West Bengal (Midnapur). The objective was to analyze the health hazard, if any, underlying the use of wastewater and solid waste for cultivation of green leafy vegetables at ECW. The following results were obtained upon comparing the data collected from the two different sites: (a) higher accumulation in ECW grown plants of elements like Ca, Cu and Pb in Amaranthus caudatus; of Ca in Amaranthus blithum; of Cl and Cu in Spinacia oleracea, (b) for the same species grown in non-ECW site, higher concentration of elements like Mn and Fe in Amaranthus caudatus; of Cl, Mn and Br in Amaranthus blithum; of Ca, Mn, Fe and Br in Spinacia oleracea. The net consumption of the aforementioned elements per person per day was calculated and found to be much below the Recommended Dietary Allowance (RDA) levels in all cases. Thus the vegetables grown out of integrated resource recovery mechanism at East Calcutta Wetland appear to be safe for human consumption. This further corroborated by the healthy appearance of these vegetables. This result has profound implications of far reaching significance for environmental management and health economics.
... Recently, rice and associated soil samples have been collected from 50 sampling sites throughout Japan to obtain TF values for stable isotopes, Th, and U for white rice and brown rice (Uchida et al., 2007). No major differences were observed between the TF values obtained in recent and older studies (Komamura and Tsumura 1994;Lakshamanan and Venkateswarlu, 1988;Li et al., 2006;Morishima et al. 1977;Sasaki et al., 2002;Sheppard et al., 1989;Yunoki et al., 1993). The GMs for TF-Th and TF-U in Uchida et al. (2007) were 1.4 Â 10 À4 and 2.8 Â 10 À4 for brown rice and 1.7 Â 10 À4 and 1.9 Â 10 À4 for white rice, respectively. ...
The critical paths for radionuclides and the critical foods in Asian countries differ from those in Western countries because agricultural products and diets are different. Consequently, safety assessments for Asian countries must consider rice as a critical food. As most rice is produced under flooded conditions, the uptake of radionuclides by rice is affected by soil conditions. In this report, we summarize radionuclide and stable element soil-to-plant transfer factors (TFs) for rice. Field observation results for fallout (137)Cs and stable Cs TFs indicated that while fallout (137)Cs had higher TF than stable Cs over several decades, the GM (geometric mean) values were similar with the GM of TF value for (137)Cs being 3.6 x 10(-3) and that for stable Cs being 2.5 x 10(-3). Although there are some limitations to the use of TF for stable elements under some circumstances, these values can be used to evaluate long-term transfer of long-lived radionuclides in the environment. The compiled data showed that TF values were higher in brown rice than in white rice because distribution patterns for elements were different in the bran and white parts of rice grains.
... Depending on the type of plant and the environmental conditions, U TFs range from 10 À4 to 1 kg kg À1 . Leafy vegetables generally show higher U TFs, followed by root, fruit and grain crops (Sheppard et al., 1984; Frissel and van Bergeijck, 1989; Lakshmanan and Venkateswarlu, 1988; Mortvedt, 1994). TF values for the plants that have been studied rarely exceed 0.1 kg kg À1 , except for plants grown on highly contaminated, often acidic, U mining sites (Whicker and Ibrahim, 1985; Whicker, 1988, 1992) or on soils with high calcium carbonate content (Shahandeh and Hossner, 2002a,b). ...
The present study aimed to quantify the influence of soil parameters on uranium uptake by ryegrass. Ryegrass was established on eighteen distinct soils, spiked with (238)U. Uranium soil-to-plant transfer factors (TF) ranged from 0.0003 to 0.0340kgkg(-1). There was no significant relation between the U soil-to-plant transfer (or total U uptake or flux) and the uranium concentration in the soil solution or any other soil factor measured, nor with the U recovered following selective soil extractions. Multiple linear regression analysis resulted in a significant though complex model explaining up to 99% of variation in TF. The influence of uranium speciation on uranium uptake observed was featured: UO(2)(+2), uranyl carbonate complexes and UO(2)PO(4)(-) seem the U species being preferentially taken up by the roots and transferred to the shoots. Improved correlations were obtained when relating the uranium TF with the summed soil solution concentrations of mentioned uranium species.
A study was carried out to determine the levels of 5 heavy metal pollutants in water, sediments and grass from the gold mining area of Koekemoerspruit near Orkney in the North West province of South Africa. Fecal and blood samples of cattle grazing and watering from the same area were also analysed. Similar samples from Mafikeng, a mining activity free area 200 km away from Orkney were used for comparison. Determination of heavy metal levels was carried out using the Atomic Absorption Spectrophotometer (AAS) machine, ICP-MS and confirmed on the AAS 700S. Uranium (U), Arsenic (As), Lead (Pb), Cadmium (Cd) and Aluminum (Al) all occurred in varying amounts in samples from both locations. The levels of all the heavy metals analysed for were significantly higher in soil, water and grass samples from Koekemoerspruit than those from Mafikeng, except for Al which was higher in grass samples from Mafikeng. Koekemoerspruit water samples had As, Al and Cd levels of 0.12, 12.8 and 0.01 ppm that were several magnitudes higher than the WHO/EPA maximum permissible levels for drinking water of 0.01, 0.2 and 0.003 ppm, respectively. The animals from both locations had varying levels of all the heavy metals in their serum and faeces. However, significantly higher levels in serum and faeces for Koekemoerspruit were found for U, Cd and Pb, indicating possible implications on the food chain. Sediments had higher levels of heavy metals than water, ranging from 10 times higher for Al to 350 times higher for U. Results of the present survey reveal possible public health risks with regards to the water levels of Al, Cd and As in the mining area of Koekemoerspruit, as well as a generally higher contribution of the mining activities to a higher heavy metal presence in the environment. Owing to the influence of the environmental levels of heavy metals on fecal and serum levels, as well as the excessively high levels of environmental Al, further studies on the possible effects of high environmental levels of the heavy metals on various aspects of animal health and agricultural production are indicated.
Effect of different (1, 5, 25, 125, 625 μg.g-1) concentrations of uranium added to soil were studied on the content of chlorophyll a, 6, total chlorophyll content, leaf soluble proteins, phenols, accumulation and translocation of uranium in wheat grown in sandy loam soil. Chlorophyll content showed significant negative correlation with applied uranium concentrations. Leaf soluble proteins showed an enhancement as the concentration of applied uranium was increased indicating an increased break down of structural or insoluble proteins. Total phenols also showed an increase with uranium additions. However, an inverse but significant correlation was also observed between amount of total phenol and dry matter production. Roots accumulated maximum content of uranium followed by shoot and seeds. A decrease in translocation ratio at higher uranium concentrations might be due to reduced metabolic activity of roots.
Toxic effects of various doses of uranium on different growth parameters in Tritk'um aestivuw during early seedling growth were studied. Root-shoot length, fresh and dry weight and chlorophyll showed a decrease even at the lowest (1.25 μg.ml-1) uranyl dose studied. Soluble proteins and phenols showed an increasing trend with increasing uranium doses. Though germination speed was affected ultimate germination was always 100%.
The purpose of this report is to provide an overview of remediation technologies that are particularly suited to the remediation of dispersed contamination. Dispersed low level contamination poses a particular challenge to those charged with its remediation. Many techniques are not efficient below certain concentration thresholds or entail more severe impacts on certain environmental compartments than the contamination itself. The technologies are outlined in brief and their advantages and limitations are discussed. The need for a holistic design of the remedial action is stressed.
In this Chapter we consider radionuclide uptake and translocation in tropical crops and ecosystems. There are many commonalities across all ecosystems because of the consistent, underlying mechanisms controlling the fate and behaviour of radioactivity in any environment. The basic radioecological concepts and models are described to cover these processes.However, the tropics and sub-tropics include much dissimilarity by way of soil types, agricultural methods, climate, plants and animals which give rise to different outcomes from those processes. Billions of people across the tropics and sub-tropics are supported by agricultural systems very different from those traditionally applied in more developed regions of the planet. Higher populations will do so in the foreseeable future. Given the push for nuclear developments in the region, the tropics will need greater attention now. Much of the science is under review but the available data, pertinent to tropical systems, has been summarised or the database identified for the reader.The conditions of tropical soil types and the factors influencing radionuclide biogeochemistry (which affects bioavailability and bioaccessibility) are discussed. Specific sections covering rice, tropical fruits and the limited data for tropical animals are included.
Radioactive accidents in the pasts and contamination of soil due to various radioactive materials have necessitated the use of all possible measures for the decontamination of land with minimal loss to the environment. This contamination is caused due to nuclear testing, nuclear waste disposal and sometimes accidents at nuclear power generation plants. Phytoremediation of such contaminated lands provides a very economic and environmentally friendly option which may be utilized on a sustainable basis. The accumulation of radionuclides in soils and their impacts on plants in the nearby areas need to be investigated. The current chapter discusses the knowledge gained after several investigations at sites contaminated due to nuclear radioactive materials. The problem, extent and nature of problem at radioactive contaminated sites and how plants may be utilized for the decontamination of lands and the problems associated with this strategy have been summarized here.
The sources of uranium in agricultural soils can be divided into two main groups: those inherent to the soil-forming rocks and those produced by anthropic inputs (Alloway, 1995). The latter factor is of great interest in the Ebro basin because of the extensive use of phosphate fertilizers, that may contain significant amounts of U. Furthermore, the presence of old brown coal mines and a nuclear power plant located near the studied area could contribute to the increase of this radionuclide. Monitoring the uranium levels in these soils is necessary due to the importance of the delta as a rice producing area. The main objectives of this work were: (1) analyze the uranium content in the considered soils and in the rice grains harvested in those soils and (2) the establishment of some relationships between uranium levels in soils and edaphic properties. In order to achieve the mentioned above objectives, 57 soil samples belonging to 19 soil sites –taken at three depths: upper soil layer (0-5 cm), subsurface soil layer (5-20 cm) and bottom soil layer (20-40 cm)-and 19 rice samples (corresponding to each soil sample) were collected and analyzed. The uranium was extracted from soil (previously dried at room temperature and sieved through a 2 mm pore mesh) with aqua-regia (total content) and EDTA 0.05M at pH=7.0 ("available" content). Rice seeds were digested by a mixture of nitric acid and hydrogen peroxide in teflon containers heated in a microwave oven. The uranium content was analyzed by means of ICP-MS (Perkin-Elmer Elan-6000). Also the following physico-chemical properties of soils were studied: pH w (1:2,5), EC (1:5 soil:water), calcium carbonate, organic matter and clay content. Descriptive statistics, simple correlation analysis and 1-way ANOVA were applied to the raw data set. The uranium content in these soils (total fraction) and rice agreed with the "safety levels" cited in the current literature.
The potential to phytoextract uranium (U) from a sandy soil contaminated at low levels was tested in the greenhouse. Two soils were tested: a control soil (317 Bq 238 U kg -1 ) and the same soil washed with bicarbonate (69 Bq 238 U kg -1 ). Ryegrass ( Lolium perenne cv. Melvina ), Indian mustard ( Brassica juncea cv. Vitasso ), and Redroot Pigweed ( Amarathus retroflexus ) were used as test plants. The annual removal of the soil activity with the biomass was less than 0.1%. The addition of citric acid (25 mmol kg -1 ) 1 week before the harvest increased U uptake up to 500-fold. With a ryegrass and mustard yield of 15000 kg ha -1 and 10000 kg ha -1 , respectively, up to 3.5% and 4.6% of the soil activity could annually be removed with the biomass. With a desired activity reduction level of 1.5 and 5 for the bicarbonate washed and control soil, respectively, it would take 10 to 50 years to attain the release limit. A linear relationship between the plant 238 U concentration and the 238 U concentration in the soil solution of the control, bicarbonate-washed, or citric acid-treated soil points to the importance of the soil solution activity concentration in determining U uptake and hence to the importance of solubilising agents to increase plant uptake. However, citric acid addition resulted in a decreased dry weight production (all plants tested) and crop regrowth (in case of ryegrass).
Phytoremediation of uranium (U) contaminated soil has been hampered by a lack of information relating U speciation to plant uptake. The goals of the present study are to (1) provide fundamental information regarding uptake of U by plants; and (2) improve the phytoextraction of U from contaminated soil. The first was achieved through speciation modeling and hydroponic experiments that demonstrated that the uranyl (UO22+) cation is the chemical species of U most readily accumulated in plant shoots. A subsequent soil incubation experiment examined the solubilization of U from contaminated soil by synthetic chelates and organic acids. The results indicated that citric acid solubilized >100 times more U than the other amendments. The results of the hydroponic and soil experiments were then integrated in a study that grew red beets in U-contaminated soils amended with citric acid or N-hydroxylethylene diamine triacetic acid. Citric acid was again a highly effective amendment, increasing shoot U content by 14-fold compared to controls. In addition to providing fundamental information regarding the uptake of U by plants, this study illustrates the importance of basic research to phytoremediation.
Uptake of depleted uranium (DU, U) derived from weathered munitions was assessed in a greenhouse experiment utilizing three common grass species, Schizachyrium scoparium (little bluestem), Buchloe dactyloides (buffalograss), and Aristida purpurea (purple threeawn). Both aboveground and belowground uptake was dependent on the soil DU concentration, and on the experimental moisture regime utilized during the experimental duration. Uptake was enhanced under higher moisture regimes, suggesting a greater degree of DU solubility and concomitant plant availability. Concentration ratios (calculated by dividing plant tissue DU concentrations by soil DU concentrations) decreased with increasing soil DU concentrations, but increased as more moisture was applied. The toxicity level of DU in root tissue was estimated to 270 mg kg.
Uranium (U) uptake and translocation by plants was characterized using a computer speciation model to develop a nutrient culture system that provided U as a single predominant species in solution. A hydroponic uptake study determined that at pH 5.0, the uranyl (UO2(2+)) cation was more readily taken up and translocated by peas (Pisum sativum) than the hydroxyl and carbonate U complexes present in the solution at pH 6.0 and 8.0, respectively. A subsequent experiment tested the extent to which various monocot and dicot species take up and translocate the uranyl cation. Of the species screened, tepary bean (Phaseolus acutifolius) and red beet (Beta vulgaris) were the species showing the greatest accumulation of U. In addition to providing fundamental information regarding U uptake by plants, the results obtained also have implications for the phytoremediation of U-contaminated soils. The initial characterization of U uptake by peas suggested that in the field, a soil pH of <5.5 would be required in order to provide U in the most plant-available form. A pot study using U-contaminated soil was therefore conducted to assess the extent to which two soil amendments, HEDTA and citric acid, were capable of acidifying the soil, increasing U solubility, and enhancing U uptake by red beet. Of these two amendments, only citric acid proved effective, decreasing the soil pH to 5.0 and increasing U accumulation by a factor of 14. The results of this pot study provide a basis for the development of an effective phytoremediation strategy for U-contaminated soils.
Two former uranium mines and a uranium reprocessing factory in the city of Aktau, Kazakhstan, may represent a risk of contaminating the surrounding areas by uranium and its daughter elements. One of the possible fingerprinting tools for studying the environmental contamination is using plant samples, collected in the surroundings of this city in 2007 and 2008. The distribution pattern of environmental pollution by uranium and thorium was evaluated by determining the thorium and uranium concentrations in plant samples (Artemisia austriaca) from the city of Aktau and comparing these results with those obtained for the same species of plants from an unpolluted area (town of Kurchatov). The determination of the uranium and thorium concentrations in different parts of A. austriaca plants collected from the analyzed areas demonstrated that the main contamination of the flora in areas surrounding the city of Aktau was due to dust transported by the wind from the uranium mines. The results obtained demonstrate that all the areas surrounding Aktau have a higher pollution level due to thorium and uranium than the control area (Kurchatov). A few "hot points" with high concentrations of uranium and thorium were found near the uranium reprocessing factory and the uranium mines.
Over 50% of the wells in the Nambe region of northern New Mexico exceed the US Environmental Protection Agency's recommended drinking water standard of 20 microg l(-1) for 238U; the highest in the area was measured at 1,200 microg U l(-1). Uranium uptake was estimated in tomato (Lycopersicon esculentum), squash (Cucurbita pepo), lettuce (Lactuca scarriola), and radish (Raphanus sativus) irrigated with Nambe well water containing <1, 150, 500, and 1,200 microg U l(-1). Plant uptake and human dose and toxicity associated with ingestion of water and produce and inhalation of irrigated soil related to gardening activities were evaluated. Uranium concentration in plants increased linearly with increasing U concentration in irrigation water, particularly in lettuce and radish. The estimated total committed effective dose for 70 years of maximum continuous exposure, via the three pathways to well water containing 1,200 microg U l(-1), was 0.17 mSv with a corresponding kidney concentration of 0.8 microg U g(-1) kidney.
Hairy root cultures of Brassica juncea and Chenopodium amaranticolor were developed by genetic transformation using Agrobacterium rhizogenes. The stable, transformed root systems demonstrated a high growth rate of 1.5-3.0 g/g dry weight/day in Murashige and Skoog medium. In the present study, hairy root system was used for removal of uranium from the solution of concentration up to 5,000 microM. The results indicated that the hairy roots could remove uranium from the aqueous solution within a short period of incubation. B. juncea could take up 20-23% of uranium from the solution containing up to 5,000 microM, when calculated on g/g dry weight basis. C. amaranticolor showed a slow and steady trend in taking up uranium, with 13% uptake from the solution of 5,000 microM concentration. Root growth was not affected up to 500 microM of uranium nitrate over a period of 10 days.
Experimental study on the behavior of uranium on soils was carried out using three kinds of soil; volcanic ash, alluvial and sandy soils. The results are as follows ; 1) Uranium dissolved in water (1-100 μeg as U/ml) was almost completely adsorbed on every soil examined. 2) The desorption of uranium from soil with salt solutions was extremely difficult especially from volcanic ash soil.
Input materials, products and by-products from a number of Florida phosphate mines and chemical plants were analyzed for 226Ra and 238U by high resolution gamma spectrometry. Concentrations were distinctly lower in North Florida than in Central Florida. In the matrix, the two nuclides were essentially in radioactive equilibrium (North Florida, 8 pCi/g; Central Florida, 38 pCi/g). Following beneficiation, concentrations in rock product, waste clays and sand tailings were approx. 100-300%, 100% and 10-25%, respectively, of those in the matrix. Radioactive equilibrium is markedly disrupted in phosphoric acid production; uranium follows the phosphoric acid while 226Ra appears in the by-product gypsum (North Florida, 14 pCi/g; Central Florida, 26 pCi/g) and also in sediments and scales. Ammoniated phosphate fertilizers had relatively low levels of 226Ra but significant 238U (North Florida, 25 pCi/g; Central Florida, 70 pCi/g). On the other hand, triple superphosphate had significant concentrations of both 226Ra (North Florida, 12 pCi/g; Central Florida, 20 pCi/g) and 238U (North Florida, 26 pCi/g; Central Florida, 56 pCi/g). In the electric furnace process, radioactivity is transferred to the slag (Central Florida, 61 pCi/g of each nuclide). Within either region, nearly all sample types showed a considerable range of concentrations. (C)1979Health Physics Society
This book is intended as a laboratory reference tool. The separate book chapters have been written by workers in the various fields covered, with a couple written by the contributing editor, Clement J. Rodden. The chapters were abstracted separately for the database.
To study the behaviour and distribution of uranium in the environment, the uranium contents in various vegetables, soils and irrigation water collected at several districts including a district near an uranium mine were investigated. Results obtained are as follows; Uranium contents of vegetables varied widely from 0.002 to 0.88 μg/g of ash. Uranium contents of leafy and root vegetables were large compared with those of berries and grains. Concentration ratios from soils to vegetables and those from irrigation water to vegetables were 10 -5-10 -3 and 1-100, respectively. In leafy and root vegetables, and also in potatoes with higher concentration ratios from both soils and water, a significant difference in uranium contents was observed among different districts. Closer correlation between uranium and phosphorus than that between uranium and calcium was observed in leafy vegetables.
Uranium is found in ground and surface waters due to its natural occurrence. In some cases, its presence is due to human activities such as mining and milling uranium. Thus, it is also found in drinking water. The range of concentrations existing in drinking water supplies in the U.S. is tabulated and examined. The range of isotopic abundances are also listed. Projections from the available data lead to estimates that of the 59,812 community drinking water supplies in the U.S., 25-650 would exceed a uranium concentration of 20 pCi/l., 100-2000 would exceed 10 pCi/l. and 2500-5000 would exceed 5 pCi/l.
Food -An Interactive Code to Calculate Internal Radiation Doses from Contaminated Food Products', in Environmental Modelling and Stimulation
- D A Baker
- G R Hoemes
- J K Soldat
- Epa
- D C Washington
- R C Cothern
- W L Buch
- J B Hursh
- N L Spoor
Baker, D. A., Hoemes, G. R., and Soldat, J. K.: 1976, 'Food -An Interactive Code to Calculate Internal Radiation Doses from Contaminated Food Products', in Environmental Modelling and Stimulation, Proc. Conf. held in Cincinnatii, OH, pp. 204-208, EPA, Washington, D.C. Cothern R. C. and Buch, W. L.: 1983, Health Physics 45, 89. Hursh, J. B. and Spoor, N. L.: 1973, in H. C. Hodge, J. S. Stannard, and J. V. Hursh, Uranium, Plutonium, Transuranic Elements. Springer-Verlag, New York.
Photometric and Fluorimetric Methods of Analysis: Metals, Part 2
- F D Snell
Snell, F. D.: 1978, Photometric and Fluorimetric Methods of Analysis: Metals, Part 2, pp. 1374-1379.
Analysis of Essential Nuclear Material, Division of Tech. Information
- C J Rodden
Food - An Interactive Code to Calculate Internal Radiation Doses from Contaminated Food Products
- D A Baker
- G R Hoemes
- J K Soldat