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P. Manirakiza

Bio: P. Manirakiza is an academic researcher from University of Antwerp. The author has contributed to research in topics: Pesticide residue & Pesticide. The author has an hindex of 10, co-authored 12 publications receiving 739 citations.

Papers
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Journal ArticleDOI
TL;DR: Soxhlet method was used in hot and standard extraction mode and compared with liquid-liquid extraction methods for lipid determination in food samples as discussed by the authors, and the comparison of extracted lipid amounts showed that, depending on the type of sample, some methods present serious limitations.

302 citations

Journal ArticleDOI
TL;DR: Concentrations of selected organochlorine pesticides and PCBs in seven fish species from the north end of the LakeTanganyika, Burundi, Africa were determined and there is no evidence that Lake Tanganyika is more contaminated with pesticides than other African water bodies.

100 citations

Journal ArticleDOI
TL;DR: Different bioconcentration factors for sum HCHs, sum DDTs, and sum endosulfans obtained in this study allow us to confirm the complex processes already reported in the literature concerning the uptake and translocation of chemicals from soil to plant.
Abstract: Validated analytical procedures for the determination of 21 organochlorine pesticides have been applied to 74 water samples, 76 soil samples, and 160 vegetable samples from nine Sene-Gambian farms. Mean pesticide residue levels found were compared to the results of other studies. The main contaminants were DDTs in water (231.9 ng/L), in soil (71.4 ng/g), and in vegetables (5.03 ng/g). The distribution of pesticide residues in water and neighboring soils and the soil–plant transfer of these pesticides is briefly discussed. Different bioconcentration factors for sum HCHs, sum DDTs, and sum endosulfans obtained in this study allow us to confirm the complex processes already reported in the literature concerning the uptake and translocation of chemicals from soil to plant.

51 citations


Cited by
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Journal ArticleDOI
TL;DR: This work expects progress in SIA resulting from standardization of methods and models, calibration of model parameters through experimentation, andContinuing to be a useful tool in reconstructing diets, characterizing trophic relationships, elucidating patterns of resource allocation, and constructing food webs.
Abstract: Stable isotope analysis (SIA) has proven to be a useful tool in reconstructing diets, characterizing trophic relationships, elucidating patterns of resource allocation, and constructing food webs. Consequently, the number of studies using SIA in trophic ecology has increased exponentially over the past decade. Several subdisciplines have developed, including isotope mixing models, incorporation dynamics models, lipid-extraction and correction methods, isotopic routing models, and compound-specific isotopic analysis. As with all tools, there are limitations to SIA. Chief among these are multiple sources of variation in isotopic signatures, unequal taxonomic and ecosystem coverage, over-reliance on literature values for key parameters, lack of canonical models, untested or unrealistic assumptions, low predictive power, and a paucity of experimental studies. We anticipate progress in SIA resulting from standardization of methods and models, calibration of model parameters through experimentation, and continu...

784 citations

Journal ArticleDOI
TL;DR: The presence of mixtures of pesticide residues in soils are the rule rather than the exception, indicating that environmental risk assessment procedures should be adapted accordingly to minimize related risks to soil life and beyond.

540 citations

Book ChapterDOI
01 Jan 2004
TL;DR: In this paper, the authors focus on the role of agriculture and fishing in the European level in the Common Agricultural Policy (CAP) and Common Fisheries Policy (CFP) and show that agriculture dominates in terms of direct contribution to GDP and numbers of people engaged in it, as well as accounting for the largest amount of public support expenditure.
Abstract: Agriculture and fishing are the primary source of almost all our food, as well as of many other products, so remain vital activities even though their share in the economy is small and in continuous decline. Partly for this reason public policy in these areas is almost entirely integrated at European level in the Common Agricultural Policy (CAP) and Common Fisheries Policy (CFP). Forestry policies are also heavily affected by EU-level decision-making. As agriculture dominates in terms of direct contribution to GDP and numbers of people engaged in it, as well as accounting for the largest amount of public support expenditure, it is agriculture that will receive the greatest attention here.

468 citations

Journal ArticleDOI
TL;DR: The arithmetic correction techniques of mass balance and lipid correction were sensitive to the C:N of the lipid-extracted tissue and to the assumed depletion of lipid delta13C relative to protein delta13N, but the mass balance approach was appropriate for the mathematical correction of bulk tissue data in most circumstances.
Abstract: For accurate interpretation of fish trophodynamics from carbon stable isotope data it is necessary to extract tissue lipids. This is because lipid content varies within and among tissues in both space and time, and because lipids are 13C-depleted relative to proteins. However, lipid extraction may affect δ15N, thus requiring costly and time-consuming separation of δ13C and δ15N analyses. These problems have prompted the development of arithmetic correction techniques for δ13C, but the techniques and their underlying assumptions have not been systematically tested. This study compared the effects of lipid extraction and arithmetic correction techniques on δ13C and δ15N of European sea bass (Dicentrarchus labrax) tissues. Following Folch lipid extraction from muscle and liver, there was a mean increase in δ15N of 0.77‰, but enrichment varied with lipid content such that effects on δ15N were hard to predict. Changes in δ13C and C:N between untreated and lipid-extracted samples reflected the quantity of lipid removed. The arithmetic correction techniques of mass balance and lipid correction were sensitive to the C:N of the lipid-extracted tissue and to the assumed depletion of lipid δ13C relative to protein δ13C. However, the mass balance approach was appropriate for the mathematical correction of bulk tissue data in most circumstances, provided that the C:N of lipid-extracted tissue could be determined for a small proportion of samples. Application of mass balance arithmetic correction can lead to significant time and cost savings in trophodynamic studies, because the majority of δ13C and δ15N analyses would not need to be run separately. Copyright © 2006 John Wiley & Sons, Ltd.

376 citations