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Cook M, Kleinschmidt R, Brugger J, Wong VNL. Transport and migration of plutonium in different soil types and rainfall regimes. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 248:106883. [PMID: 35468420 DOI: 10.1016/j.jenvrad.2022.106883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
Leaching and transport of contaminants is a complex interacting system affected by a suite of environmental factors. This study demonstrates the potential significance of weather events and moisture movement when interpreting plutonium (Pu) migration and advective transport in the soil matrix. Using a column transport experiment, two soil types, a sandy soil and clay-rich soil, were spiked with 238Pu as a tracer to observe the effect of simulated tropical and arid rainfall events on Pu mobility. Partition coefficients (Kd) were determined over a period of weeks and under varying rainfall rates to establish the impact of changing weather events on Pu mobility. The variability of these temporal Kds covers six orders of magnitude over a relatively brief time period. This demonstrates the necessity for non-static Kds to accurately describe Pu transport in these systems. The Pu Kds determined by these column transport experiments fall within the bounds of anticipated values (approximately 80-300,000 mL g-1) from immobile (magnitude 106 mL g-1) to moderately mobile (magnitude 101 mL g-1). The overall transport rate, shown by a decrease in calculated Kd, increases in environments where rainfall is more episodic, such as in arid regions as opposed to the consistently abundant rainfall in tropical regions. In contrast to the 238Pu spike, 239+240Pu resulting from contamination from nuclear tests in the sandy soil (aged for >30 years) showed higher mobility; we hypothesise that the ageing of the contamination, in particular Pu-bearing particles, accounts for this significant increase in Pu mobility. Low intensity, high frequency events in tropical sandy soil systems containing Pu particle contamination have the potential to mobilise Pu (>105 decrease in calculated Kd) over shorter periods of weeks, and not years as previously assumed. This increased mobility, when applied to radioecological models using Kd as a site-specific parameter, shows that there is likely to be a continued impact (risk quotient >1) on non-human biota in tropical sandy soil ecosystems.
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Affiliation(s)
- Megan Cook
- School of Earth, Atmosphere & Environment, Monash University, Australia.
| | - Ross Kleinschmidt
- Epic Environmental, PO Box 13058, Brisbane Queensland, 4003, Australia
| | - Joël Brugger
- School of Earth, Atmosphere & Environment, Monash University, Australia
| | - Vanessa N L Wong
- School of Earth, Atmosphere & Environment, Monash University, Australia
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Ujwal P, Yashodhara I, Sudeep Kumara K, Ravi PM, Karunakara N. Environmental transfer parameters of strontium for soil to cow milk pathway for tropical monsoonal climatic region of the Indian subcontinent. Sci Rep 2022; 12:7528. [PMID: 35534517 PMCID: PMC9085734 DOI: 10.1038/s41598-022-11388-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 04/22/2022] [Indexed: 11/09/2022] Open
Abstract
The radionuclide transfer between compartments is commonly described by transfer parameters representing the ratio of concentrations of an element in two compartments for equilibrium conditions. This is a comprehensive study on the soil-to-grass transfer factor (Fv) and grass-to-cow milk transfer coefficient (Fm) for stable strontium (Sr) for soil-grass (pasture)-cow (Bos taurus) milk environmental pathway under field conditions for a high rainfall tropical monsoonal climatic region of the Indian subcontinent. The study was conducted in the vicinity of the Kaiga nuclear power plant (NPP), situated ~ 58 km inland of the West Coast of the Indian subcontinent. A grass field was developed exclusively for this study, and two cows of the native breed were raised to graze on it. The soil, grass, and milk were analyzed to evaluate the Fv and the Fm values for the stable Sr. For comparison, several pasture lands and the cows raised by the villagers and a dairy farm were also studied. The Fv values were in the range 0.18-8.6, the geometric mean (GM) being 1.8. The correlations of Fv values with a range of physicochemical parameters are presented. The GM values for Fm were 2.2 × 10-3 d L-1 and 7.2 × 10-3 d L-1 for the two cows raised for this study, 2.6 × 10-3 d L-1 for those raised by the villagers, and 4.2 × 10-3 d L-1 for the dairy farm. The site-specific Fm value for the region was determined as 3.2 × 10-3 d L-1. The concentration ratio (CR), defined as the ratio of Sr concentration in milk to that in feed under equilibrium conditions, exhibited less variability (1.8 × 10-2-5.4 × 10-2) among the three categories of cows.
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Affiliation(s)
- P Ujwal
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
- Department of Science and Humanities, Rajarambapu Institute of Technology, Sangli, Maharastra, 415414, India
| | - I Yashodhara
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - K Sudeep Kumara
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - P M Ravi
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - N Karunakara
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India.
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Doering C, Carini F, Sato M, Howard BJ, Harbottle AR, Brown J, Twining J, Velasco H. Updated soil to fruit concentration ratios for radiocaesium compiled under the IAEA MODARIA II Programme. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2022; 42:020511. [PMID: 35506679 DOI: 10.1088/1361-6498/ac6046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 03/23/2022] [Indexed: 06/14/2023]
Abstract
Under the International Atomic Energy Agency (IAEA) Modelling and Data for Radiological Impact Assessments (MODARIA II) Programme, Working Group 4 activities included collating radionuclide transfer data from Japan following the Fukushima Daiichi Nuclear Power Plant accident and separately collating concentration ratio (CR) data for root uptake of radionuclides by crops grown in tropical and arid climates. In this paper, the newly compiled radiocaesium CR data for fruit from Japan, tropical and arid climates have been combined with the data originally compiled for the IAEA Technical Reports Series No. 472 (TRS 472) and additional data identified from the literature to produce an enhanced MODARIA II dataset of fruit radiocaesium CR values. Statistical analysis of the MODARIA II dataset by climate class (based on the Köppen-Geiger climate classification) indicated that the CR values for tropical climates were significantly higher (p< 0.05) than those for arid, temperate and cold climates. Statistical analysis of the MODARIA II dataset by soil group (based on soil texture) indicated that the CR values for coral sand soil (tropical climates only) and organic soil (temperate climates only) were significantly higher (p< 0.05) than those for the clay, loam and sand soil groups. Statistical analysis of the MODARIA II dataset by plant group (based on plant morphology) indicated that the CR values for non-woody trees (tropical climate bias) were significantly higher (p< 0.05) than those for herbaceous plants, shrubs and woody trees. Comparison of the MODARIA II dataset with original TRS 472 values showed only small changes in the fruit radiocaesium CR values for herbaceous plants and shrubs in temperate climates. There was a decrease in the CR values for woody trees in temperate climate across all soil groups. There was also a decrease in the CR values for tropical climates for all comparable soil groups.
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Affiliation(s)
- C Doering
- Environmental Research Institute of the Supervising Scientist, Darwin, Australia
| | - F Carini
- Università Cattolica del Sacro Cuore, Piacenza, Italy
| | - M Sato
- Faculty of Food and Agriculture, Fukushima University, Fukushima, Japan
| | - B J Howard
- Centre for Ecology and Hydrology, Lancaster, United Kingdom
- Division of Agricultural and Environmental Sciences, University of Nottingham, Nottingham, United Kingdom
| | | | - J Brown
- International Atomic Energy Agency, Vienna, Austria
| | - J Twining
- Austral Radioecology, Sydney, Australia
| | - H Velasco
- GEA-Instituto de Matemática Aplicada San Luis (IMASL), Universidad Nacional de San Luis, Consejo Nacional de Investigaciones Científicas y Técnicas., San Luis, Argentina
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Juárez-Juárez B, Cuautle M, Castillo-Guevara C, López-Vázquez K, Gómez-Ortigoza M, Gómez-Lazaga M, Díaz-Castelazo C, Lara C, Pérez-Toledo GR, Reyes M. Neither ant dominance nor abundance explain ant-plant network structure in Mexican temperate forests. PeerJ 2020; 8:e10435. [PMID: 33354422 PMCID: PMC7727367 DOI: 10.7717/peerj.10435] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 11/06/2020] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Ant-plant mutualistic networks tend to have a nested structure that contributes to their stability, but the ecological factors that give rise to this structure are not fully understood. Here, we evaluate whether ant abundance and dominance hierarchy determine the structure of the ant-plant networks in two types of vegetation: oak and grassland, in two temperate environments of Mexico: Flor del Bosque State Park (FBSP) and La Malinche National Park (MNP). We predicted that dominant and abundant ant species make up the core, and submissives, the periphery of the network. We also expected a higher specialization level in the ant trophic level than in plant trophic level due to competition among the ant species for the plant-derived resources. METHODS The ant-plant interaction network was obtained from the frequency of ant-plant interactions. We calculated a dominance hierarchy index for the ants using sampling with baits and evaluated their abundance using pitfall traps. RESULTS In MNP, the Formica spp. species complex formed the core of the network (in both the oak forest and the grassland), while in FBSP, the core species were Prenolepis imparis (oak forest) and Camponotus rubrithorax (grassland). Although these core species were dominant in their respective sites, they were not necessarily the most dominant ant species. Three of the four networks (oak forest and grassland in FBSP, and oak forest in MNP) were nested and had a higher number of plant species than ant species. Although greater specialization was observed in the ant trophic level in the two sites and vegetations, possibly due to competition with the more dominant ant species, this was not statistically significant. In three of these networks (grassland and oak forest of MNP and oak forest of FBSP), we found no correlation between the dominance hierarchy and abundance of the ant species and their position within the network. However, a positive correlation was found between the nestedness contribution value and ant dominance hierarchy in the grassland of the site FBSP, which could be due to the richer ant-plant network and higher dominance index of this community. CONCLUSIONS Our evidence suggests that ant abundance and dominance hierarchy have little influence on network structure in temperate ecosystems, probably due to the species-poor ant-plant network and a dominance hierarchy formed only by the presence of dominant and submissive species with no intermediate dominant species between them (absence of gradient in hierarchy) in these ecosystems.
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Affiliation(s)
- Brenda Juárez-Juárez
- Maestría en Biotecnología y Manejo de Recursos Naturales, Centro de Investigación en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, San Felipe Ixtacuixtla, Tlaxcala, Mexico
| | - Mariana Cuautle
- Departamento de Ciencias Químico Biológicas, Universidad de las Américas Puebla, San Andrés Cholula, Puebla, Mexico
| | - Citlalli Castillo-Guevara
- Centro de Investigación en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, San Felipe Ixtacuixtla, Tlaxcala, Mexico
| | - Karla López-Vázquez
- Centro de Investigación en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, San Felipe Ixtacuixtla, Tlaxcala, Mexico
| | - María Gómez-Ortigoza
- Departamento de Ciencias Químico Biológicas, Universidad de las Américas Puebla, San Andrés Cholula, Puebla, Mexico
| | - María Gómez-Lazaga
- Departamento de Ciencias Químico Biológicas, Universidad de las Américas Puebla, San Andrés Cholula, Puebla, Mexico
| | - Cecilia Díaz-Castelazo
- Red de Interacciones Multitróficas, Instituto de Ecología A.C., Xalapa, Veracruz, Mexico
| | - Carlos Lara
- Centro de Investigación en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, San Felipe Ixtacuixtla, Tlaxcala, Mexico
| | | | - Miguel Reyes
- Departamento de Actuaría, Física y Matemáticas, Universidad de las Américas Puebla, San Andrés Cholula, Puebla, Mexico
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Abstract
Soil organic carbon (SOC) improvement has become a sustainable strategy for enhancing soil resilience and reducing greenhouse gas (GHG) emissions in the rice cropping system. For tropical soils, the SOC accumulation was limited by the unfavorable environment, likely the sandy soil area in Northeast (NE) Thailand. This review aims to quantify and understand SOC in sandy paddy fields of NE Thailand. The existing research gap for alternative management practices is also highlighted to increase ecological and agronomic values. We review previous studies to determine the factors affecting SOC dynamics in sandy paddy fields, in order to enhance SOC and sustain rice yields. High sand content, up to 50% sand, was found in 70.7% of the observations. SOC content has ranged from 0.34 to 31.2 g kg−1 for the past four decades in paddy rice soil of NE Thailand. The conventional and alternative practice managements were chosen based on either increasing rice crop yield or improving soil fertility. The lack of irrigation water during the mild dry season would physically affect carbon sequestration as the soil erosion accelerates. Meanwhile, soil chemical and microbial activity, which directly affect SOC accumulation, would be influenced by nutrient and crop residue management, including chemical fertilizer, manure and green manure, unburned rice straw, and biochar application. Increasing SOC content by 1 g kg−1 can increase rice yield by 302 kg ha−1. The predicted carbon saturation varied tremendously, from 4.1% to 140.6% (52% in average), indicating that the sandy soil in this region has the potential for greater SOC sequestration. Our review also suggests that broadening the research of rice production influenced by sandy soil is still required to implement adaptive management for sustainable agriculture and future food security.
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Medley P, Bollhöfer A. Influence of group II metals on Radium-226 concentration ratios in the native green plum (Buchanania obovata) from the Alligator Rivers Region, Northern Territory, Australia. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 151 Pt 3:551-557. [PMID: 26277654 DOI: 10.1016/j.jenvrad.2015.07.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 07/14/2015] [Accepted: 07/15/2015] [Indexed: 06/04/2023]
Abstract
In this study, uptake of Ra from soil, and the influence of group II metals on Ra uptake, into the stones and edible flesh of the fruit of the wild green plum, Buchanania obovata, was investigated. Selective extraction of the exchangeable fraction of the soil samples was undertaken but was not shown to more reliably predict Ra uptake than total soil Ra activity concentration. Comparison of the group II metal to Ca ratios (i.e. Sr/Ca, Ba/Ca, Ra/Ca) in the flesh with exchangeable Ca shows that Ca outcompetes group II metals for root uptake and that the uptake pathway discriminated against group II metals relative to ionic radius, with uptake of Ca > Sr > Ba >> Ra. Flesh and stone analysis showed that movement of group II metals to these components of the plant, after root uptake, was strongly related. This supports the hypothesis that Sr, Ba and Ra are being taken up as analogue elements, and follow the same uptake and translocation pathways, with Ca. Comparison with previously reported data from a native passion fruit supports the use of total soil CRs on natural, undisturbed sites. As exchangeable CRs for Ra reach a saturation value it may be possible to make more precise predictions using selective extraction techniques for contaminated or disturbed sites.
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Affiliation(s)
- Peter Medley
- Environmental Research Institute of the Supervising Scientist (eriss), Darwin, NT 0810, Australia.
| | - Andreas Bollhöfer
- Environmental Research Institute of the Supervising Scientist (eriss), Darwin, NT 0810, Australia
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