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Barraza F, Schreck E, Lévêque T, Uzu G, López F, Ruales J, Prunier J, Marquet A, Maurice L. Cadmium bioaccumulation and gastric bioaccessibility in cacao: A field study in areas impacted by oil activities in Ecuador. Environ Pollut 2017; 229:950-963. [PMID: 28781181 DOI: 10.1016/j.envpol.2017.07.080] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 07/24/2017] [Accepted: 07/24/2017] [Indexed: 05/17/2023]
Abstract
Cacao from South America is especially used to produce premium quality chocolate. Although the European Food Safety Authority has not established a limit for cadmium (Cd) in chocolate raw material, recent studies demonstrate that Cd concentrations in cacao beans can reach levels higher than the legal limits for dark chocolate (0.8 mg kg-1, effective January 1st, 2019). Despite the fact that the presence of Cd in agricultural soils is related to contamination by fertilizers, other potential sources must be considered in Ecuador. This field study was conducted to investigate Cd content in soils and cacao cultivated on Ecuadorian farms in areas impacted by oil activities. Soils, cacao leaves, and pod husks were collected from 31 farms in the northern Amazon and Pacific coastal regions exposed to oil production and refining and compared to two control areas. Human gastric bioaccessibility was determined in raw cacao beans and cacao liquor samples in order to assess potential health risks involved. Our results show that topsoils (0-20 cm) have higher Cd concentrations than deeper layers, exceeding the Ecuadorian legislation limit in 39% of the sampling sites. Cacao leaves accumulate more Cd than pod husks or beans but, nevertheless, 50% of the sampled beans have Cd contents above 0.8 mg kg-1. Root-to-cacao transfer seems to be the main pathway of Cd uptake, which is not only regulated by physico-chemical soil properties but also agricultural practices. Additionally, natural Cd enrichment by volcanic inputs must not be neglected. Finally, Cd in cacao trees cannot be considered as a tracer of oil activities. Assuming that total Cd content and its bioaccessible fraction (up to 90%) in cacao beans and liquor is directly linked to those in chocolate, the health risk associated with Cd exposure varies from low to moderate.
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Affiliation(s)
- F Barraza
- Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées, Université de Toulouse, CNRS, IRD, 14 Avenue E. Belin, F-31400 Toulouse, France.
| | - E Schreck
- Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées, Université de Toulouse, CNRS, IRD, 14 Avenue E. Belin, F-31400 Toulouse, France
| | - T Lévêque
- Escuela Politécnica Nacional, Departamento de Ciencias de Alimentos y Biotecnología, P.O. Box 17, 012759 Quito, Ecuador
| | - G Uzu
- IGE, Université Grenoble Alpes, CNRS, IRD, CS 40700 Cedex 9, F-38058 Grenoble, France
| | - F López
- Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées, Université de Toulouse, CNRS, IRD, 14 Avenue E. Belin, F-31400 Toulouse, France
| | - J Ruales
- Escuela Politécnica Nacional, Departamento de Ciencias de Alimentos y Biotecnología, P.O. Box 17, 012759 Quito, Ecuador
| | - J Prunier
- Laboratoire des Sciences du Bois, UMR EcoFoG, ZI Pariacabo, 97387 Kourou, French Guiana
| | - A Marquet
- Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées, Université de Toulouse, CNRS, IRD, 14 Avenue E. Belin, F-31400 Toulouse, France
| | - L Maurice
- Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées, Université de Toulouse, CNRS, IRD, 14 Avenue E. Belin, F-31400 Toulouse, France
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Cuvier A, Pourcelot L, Probst A, Prunier J, Le Roux G. Trace elements and Pb isotopes in soils and sediments impacted by uranium mining. Sci Total Environ 2016; 566-567:238-249. [PMID: 27220101 DOI: 10.1016/j.scitotenv.2016.04.213] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/28/2016] [Accepted: 04/28/2016] [Indexed: 06/05/2023]
Abstract
The purpose of this study is to evaluate the contamination in As, Ba, Co, Cu, Mn, Ni, Sr, V, Zn and REE, in a high uranium activity (up to 21,000Bq∙kg(-1)) area, downstream of a former uranium mine. Different geochemical proxies like enrichment factor and fractions from a sequential extraction procedure are used to evaluate the level of contamination, the mobility and the availability of the potential contaminants. Pb isotope ratios are determined in the total samples and in the sequential leachates to identify the sources of the contaminants and to determine the mobility of radiogenic Pb in the context of uranium mining. In spite of the large uranium contamination measured in the soils and the sediments (EF≫40), trace element contamination is low to moderate (2<EF<5), except for Ba (5<EF<15), due to the precipitation of barium sulfate resulting from mining activities. Most of the trace elements are associated with the most mobile fractions of the sediments/soils, implying an enhanced potential availability. Even if no Pb enrichment is highlighted, the Pb isotopic signature of the contaminated soils is strongly radiogenic. Measurements performed on the sequential leachates reveal inputs of radiogenic Pb in the most mobile fractions of the contaminated soil. Inputs of low-mobile radiogenic Pb from mining activities may also contribute to the Pb signature recorded in the residual phase of the contaminated samples. We demonstrate that Pb isotopes are efficient tools to trace the origin and the mobility of the contaminants in environments affected by uranium mining.
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Affiliation(s)
- A Cuvier
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France; IRSN/PRP-ENV/SESURE/Laboratoire d'études radioécologiques en milieu continental et marin, BP 1, 13108 Saint Paul Lez Durance Cedex, France.
| | - L Pourcelot
- IRSN/PRP-ENV/SESURE/Laboratoire d'études radioécologiques en milieu continental et marin, BP 1, 13108 Saint Paul Lez Durance Cedex, France
| | - A Probst
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - J Prunier
- Observatoire Midi-Pyrénées, laboratoire Géosciences Environnement Toulouse, CNRS/IRD/Université Paul Sabatier, 14 avenue Edouard Belin, 31400 Toulouse, France
| | - G Le Roux
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France.
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Cuvier A, Panza F, Pourcelot L, Foissard B, Cagnat X, Prunier J, van Beek P, Souhaut M, Le Roux G. Uranium decay daughters from isolated mines: Accumulation and sources. J Environ Radioact 2015; 149:110-120. [PMID: 26232768 DOI: 10.1016/j.jenvrad.2015.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 07/09/2015] [Accepted: 07/11/2015] [Indexed: 06/04/2023]
Abstract
This study combines in situ gamma spectrometry performed at different scales, in order to accurately locate the contamination pools, to identify the concerned radionuclides and to determine the distribution of the contaminants from soil to bearing phase scale. The potential mobility of several radionuclides is also evaluated using sequential extraction. Using this procedure, an accumulation area located downstream of a former French uranium mine and concentrating a significant fraction of radioactivity is highlighted. We report disequilibria in the U-decay chains, which are likely related to the processes implemented on the mining area. Coupling of mineralogical analyzes with sequential extraction allow us to highlight the presence of barium sulfate, which may be the carrier of the Ra-226 activities found in the residual phase (Ba(Ra)SO4). In contrast, uranium is essentially in the reducible fraction and potentially trapped in clay-iron coatings located on the surface of minerals.
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Affiliation(s)
- A Cuvier
- Université de Toulouse, INP, UPS, EcoLab (Laboratoire Ecologie Fonctionnelle et Environnement), ENSAT, Avenue de l'Agrobiopole, F-31326 Castanet-Tolosan, France; IRSN/PRP-ENV/SESURE/Laboratoire d'Études Radioécologiques en milieu Continental et Marin, BP 1 13108 Saint Paul Lez Durance Cedex, France; CNRS, EcoLab, UMR 5245, 31326 Castanet Tolosan, France.
| | - F Panza
- IRSN/Pôle Radioprotection, Environnement, Déchets et Crises, Service d'Intervention et d'Assistance en Radioprotection (SIAR), 92262 Fontenay aux Roses Cedex, France
| | - L Pourcelot
- IRSN/PRP-ENV/SESURE/Laboratoire d'Études Radioécologiques en milieu Continental et Marin, BP 1 13108 Saint Paul Lez Durance Cedex, France
| | - B Foissard
- IRSN/Pôle Radioprotection, Environnement, Déchets et Crises, Service d'Intervention et d'Assistance en Radioprotection (SIAR), 92262 Fontenay aux Roses Cedex, France
| | - X Cagnat
- Institut de Radioprotection et de Sûreté Nucléaire, Bat 501 Bois des Rames, 91400 Orsay, France
| | - J Prunier
- Observatoire Midi-Pyrénées, Laboratoire Géosciences Environnement Toulouse, CNRS/IRD/Université Paul Sabatier, 14 avenue Edouard Belin, 31400 Toulouse, France
| | - P van Beek
- Observatoire Midi-Pyrénées, Laboratoire d'Etudes en Géophysique et Océanographie Spatiales UMR 5566, CNRS/CNES/IRD/Université Paul Sabatier, 14 av. Edouard Belin, 31400 Toulouse, France
| | - M Souhaut
- Observatoire Midi-Pyrénées, Laboratoire d'Etudes en Géophysique et Océanographie Spatiales UMR 5566, CNRS/CNES/IRD/Université Paul Sabatier, 14 av. Edouard Belin, 31400 Toulouse, France
| | - G Le Roux
- Université de Toulouse, INP, UPS, EcoLab (Laboratoire Ecologie Fonctionnelle et Environnement), ENSAT, Avenue de l'Agrobiopole, F-31326 Castanet-Tolosan, France; CNRS, EcoLab, UMR 5245, 31326 Castanet Tolosan, France.
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