Éditeur(s) : Elsevier
Résumé : Red drum larvae were fed from day 11 to day 24 post-hatch, with Artemia (LP group) or two isoproteinic-formulated diets with varying lipid levels, 15% (L15 group) and 30% (L30 group). The lipid fraction was composed of a mixture of cod liver oil and soy lecithin. Larvae fed Artemia exhibited the greatest length, L30 diet induced a larvae length significantly greater than that obtained with L15 diet (P < 0,05). No difference was observed in larvae survival among the three dietary groups. The increase in dietary lipid concentration led to an increase in amylase and trypsin secretion levels in 24-day-old larvae. The pancreatic secretion level measured in L30 group was close to that of LP group, suggesting that the maturation of the pancreatic functions was normally developed. Red drum larvae fed the diet containing the higher lipid content (L30) exhibited a more developed brush border membrane digestion in the intestine than larvae fed L15 diet (P < 0.05). Phospholipase A2 was stimulated by the increase of phospholipids in the diet, but no difference was observed for lipase between the two compound diet-fed groups; the LP group exhibited the lowest lipase activity. A plateau in lipase activity may have occurred in red drum larvae from 15% fat level in the diet, suggesting that the maximal lipase activity was reached with 12% neutral lipid in the diet. The positive effects observed with high dietary fat may be due to the phospholipid fraction of the lipid mixture used.
Aquaculture (0044-8486) (Elsevier), 2000-04 , Vol. 184 , N. 3-4 , P. 339-347

Droits : 2000 Elsevier
http://archimer.ifremer.fr/doc/2000/publication-503.pdf
DOI:10.1016/S0044-8486(99)00325-7
http://archimer.ifremer.fr/doc/00000/503/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Children are exposed to toxic metals and metalloids via their diet and environment. Our objective was to assess the aggregate chronic exposure of children aged 3–6 years, living in France, to As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V present in diet, tap water, air, soil and floor dust in the years 2007–2009. Dietary data came from the French Total Diet Study, while concentrations in residential tap water, soil and indoor floor dust came from the ‘Plomb-Habitat’ nationwide representative survey on children's lead exposure at home. Indoor air concentrations were assumed to be equal to outdoor air concentrations, which were retrieved from regulatory measurements networks. Human exposure factors were retrieved from literature. Data were combined with Monte Carlo simulations. Median exposures were 1.7, 0.3, 10.2, 34.1, 60.3, 0.7, 0.1, 44.3, 1.5 and 95th percentiles were 4.4, 0.5, 15.8, 61.3, 98.3, 2.5, 0.1, 111.1, 2.9 μg/kg bw/d for As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V respectively. Dietary exposures dominate aggregate exposures, with the notable exception of Pb - for which soils and indoor floor dust ingestion contribute most at the 95th percentile. The strengths of this study are that it aggregates exposures that are often estimated separately, and uses a large amount of representative data. This assessment is limited to main diet and residential exposure, and does not take into account the relative bioavailability of compounds. These results could be used to help target prevention strategies.
ISSN: 0160-4120

inserm-01404061
http://www.hal.inserm.fr/inserm-01404061
http://www.hal.inserm.fr/inserm-01404061/document
http://www.hal.inserm.fr/inserm-01404061/file/rev1%20-%20MS%20Expo%20metals.pdf
DOI : 10.1016/j.envint.2016.10.009

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
29 inorganic compounds (Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, Gd, K, Mg, Mn, Mo, Na, Nd, Ni, Pb, Sb, Se, Sr, Ti, U, V and Zn) were measured in the tap water of 484 representative homes of children aged 6 months to 6 years in metropolitan France in 2008-2009. Parents were asked whether their children consumed tap water. Sampling design and sampling weights were taken into account to estimate element concentrations in tap water supplied to the 3,581,991 homes of 4,923,058 children aged 6 months to 6 years. Median and 95th percentiles of concentrations in tap water were in mu g/L: Al: <10, 483, As: 02, 2.1; B: <100, 100; Ba: 30.7, 149.4; Ca: 85,000, 121,700; Cd: <0.5, <0.5; Ce: <0.5, <0.5; Co: <0.5, 0.8; Cr: <5, <5; Cu: 70, 720; K: 2210, 6740; Fe: <20, 46; Mn: <5, <5; Mo: <0.5,1.5; Na: 14,500, 66,800; Ni: <2,10.2; Mg: 6500,21,200; Pb: <1, 5.4; Sb: <0.5, <0.5; Se: <1, 6.7; Sr: 256.9, 1004; TI: <0.5, <0.5; U: <0.5, 2.4; V: <1, 1; Zn; 53, 208. Of the 2,977,123 young children drinking tap water in France, some were drinking water having concentrations above the 2011 World Health Organization drinking water quality guidelines: respectively 498 (CI 95%: 0-1484) over 700 mu g/L of Ba; 121,581 (CI 95%: 7091-236,070) over 50 mg/L of Na; 2044 (CI 95%: 0-6132) over 70 mu g/L of Ni, and 78,466 (17,171-139,761) over 10 mu g/L of Pb. Since it is representative, this tap water contamination data can be used for integrated exposure assessment, in conjunction with diet and environmental (dust and soil) exposure data. (C) 2016 Elsevier Ltd. All rights reserved.
ISSN: 0160-4120

hal-01390976
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01390976
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01390976/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01390976/file/Le%20Bot%202016%20EI%20revision1%20.pdf
DOI : 10.1016/j.envint.2016.06.009

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Pyrethroids are insecticides frequently used in agriculture and in the home; exposure occurs through dietary and non-dietary pathways, including indoor and outdoor environmental contamination. Our objective was to study the potential determinants of pyrethroid metabolite concentrations measured in children's urine samples and in the dust of their homes. Specifically, we measured urinary metabolites from morning spot samples of 245 six-year- old children living in Brittany (France) in 2009-2012 and from dust vacuumed from the floor of their homes. Mothers reported home insecticide use, dietary habits, sociodemographic data; residential and school proximity to agricultural crops was assessed with spatialized data. The metabolites cis-DBCA, trans-DCCA, cisDCCA, 3-PBA, and F-PBA were detected in 84, 95, 64, 63, and 16% of the urine samples, respectively. Permethrin, cypermethrin, cyfluthrin, deltamethrin, and tetramethrin pyrethroids were detected in 100, 56, 9, 15, and 26% of the dust samples, respectively. Multiple regression analysis suggested diet plays a role in children's exposure, in particular, the food groups "pasta, rice or semolina" (for cis-DCCA and F-PBA), fruit (3-PBA), "breakfast cereals and whole grain bread" (cis-DBCA), and the global proportion of organic food in diet (for cis-DBCA, trans-DCCA). Children with a parent occupationally exposed to pesticides were about 3-times more likely to have higher urinary concentrations of 3-PBA (OR = 2.8, 95% CI [1.2; 6.5]). Dust content was correlated mainly with household insecticide use: higher mean concentrations of permethrin (beta = 0.8 [0.3; 1.3], in mu g/g) and an increased risk of a detectable level of cyfluthrin (OR = 4.7 [1.7; 12.9]) were observed in home dust, for indoor use of at least twice a year. Outdoor insecticide use at least once a year was associated with detection in dust of cypermethrin (OR = 3.0 [1.3; 6.7]) and tetramethrin (OR = 3.7 [1.6; 8.3]). Three positive and one negative correlations (out of 11) between urinary metabolite concentrations and home dust contents of their possible corresponding parent compounds were observed. The strength of this study lies in its concurrent use of biomarkers, environmental measurements, and potential sources of exposure. Its limitations include the use of a single urine sample and imprecise data about pyrethroid use in local agriculture.
ISSN: 0160-4120

hal-01560147
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01560147
DOI : 10.1016/j.envint.2017.04.007
PUBMED : 28453973

Éditeur(s) : Elsevier
Résumé : Until recently, it was considered impossible to feed newly hatched marine fish species with a compound diet. Substituting a compound diet for live prey was performed several weeks after hatching, depending on the species. Compound diets were well ingested at the early stage but larvae died with a gut full of food, suggesting that larvae were unable to digest the compound diet. The hypothesis was that younger larvae have insufficient digestive enzymes to thrive on compound diets, and that exogenous enzymes, provided from live prey, are necessary for early stages.The organogenesis of marine fish larvae is not completely achieved at hatching and histological studies have revealed that the anatomy of the digestive tract undergoes developmental changes over some weeks. Nevertheless, biochemical studies over 20 years have shown that most of the digestive enzymes are present in young larvae. Recent studies have provided better understanding of digestion mechanisms in larvae and have led to proposed dietary compositions meeting larvae nutritional requirements. Pancreatic digestive enzymes are detected before mouth opening. Their synthesis is not induced by diet ingestion, but secretory mechanisms in the pancreas, and so enzymatic action, become efficient chronologically after those of synthesis. Inadequate diets can delay the onset of secretion mechanisms. The ratio of secreted enzymes to total enzymes indicates the nutritional value of the diet ingested by the larvae.At the intestinal level, cytosolic enzymes, which are peptidases, exhibit high activity in the early stages, suggesting a high capacity in larvae to digest protein hydrolysate. Indeed, larvae growth and survival is improved by the incorporation of a moderate concentration of peptide or hydrolysate in the diet. Peptidase activity abruptly decreases around day 25 in sea bass, concurrent with an increase in enzymes of the brush border membranes. This corresponds to a normal maturation process of enterocytes. Compound diets can slightly delay the onset of this maturation process, and inadequate diet can prevent it, leading to near death of the larvae. A proper onset of the maturation process has been associated with high larvae survival.The early developmental stage larvae exhibit high hydrolytic capacity, related to their weight. Enzyme activity pattern is age-dependent, but can be modulated by diet composition. Thus, larvae have the ability to digest and thrive on compound diet, if this diet is well adapted. Larvae have different specificities in digestion and nutritional requirements when compared to juveniles. Taking these specificities into consideration, recent research has led to the formulation of a compound diet that was well adapted for larvae from mouth opening, and could totally replace live prey.
Aquaculture (0044-8486) (Elsevier), 2001-08 , Vol. 200 , N. 1-2 , P. 161-180

Droits : 2001 Elsevier Science B.V. All rights reserved
http://archimer.ifremer.fr/doc/2001/publication-447.pdf
DOI:10.1016/S0044-8486(01)00699-8
http://archimer.ifremer.fr/doc/00000/447/

Éditeur(s) : HAL CCSD
Résumé : International audience
In all vertebrate species, estrogens play a crucial role in the development, growth, and function of reproductive and nonreproductive tissues. A large number of natural or synthetic chemicals present in the environment and diet can interfere with estrogen signaling; these chemicals are called endocrine disrupting chemicals (EDCs) or xenoestrogens. Some of these compounds have been shown to induce adverse effects on human and animal health, and some compounds are suspected to contribute to diverse disease development. Because xenoestrogens have varying sources and structures and could act in additive or synergistic effects when combined, they have multiple mechanisms of action. Consequently, an important panel of in vivo and in vitro bioassays and chemical analytical tools was used to screen, evaluate, and characterize the potential impacts of these compounds on humans and animals. In this paper, we discuss different molecular actions of some of the major xenoestrogens found in food or the environment, and we summarize the current models used to evaluate environmental estrogens.
Int J Endocrinol

Droits : info:eu-repo/semantics/OpenAccess
inserm-00863365
http://www.hal.inserm.fr/inserm-00863365
http://www.hal.inserm.fr/inserm-00863365/document
http://www.hal.inserm.fr/inserm-00863365/file/501851.pdf
PUBMED : 23737774

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Increasingly, health risk assessment is addressing multiple pathway exposures to multiple contaminants. We reviewed aggregated exposure and cumulative risk approaches for contemporary and ubiquitous semivolatile organic compounds (SVOC). We identified 22 studies aggregating exposure pathways, and 31 cumulating risk. Exposure aggregation is based on the addition of pathway-specific doses, using kinetic modeling where it exists, and classic external dose equations otherwise. In most cases, exposure is dominated by a single route or source of exposure - mainly the oral pathway - via dietary or non-dietary exposure. Preferential routes and sources of exposure are influenced by SVOC physical-chemical properties such as vapor pressure. The cumulative risk approach for contaminants is based on dose addition. Simple sum of hazard quotient (Hazard Index: HI) is the most commonly used cumulative risk assessment approach, while Relative Potency Factor (RPF) appeared to the best suited – although this calls for a level of toxicological information that limits the number of compounds that can be studied simultaneously. Where both were performed, moving from HI to more refined approach produced similar results. In conclusion, both approaches - exposure aggregation and cumulative risk - rely on simple assumptions. Nevertheless, they allow uncertainty to be reduced, in comparison with source-by-source or chemical-by-chemical approaches.
ISSN: 0013-9351

hal-01635759
https://hal.archives-ouvertes.fr/hal-01635759
https://hal.archives-ouvertes.fr/hal-01635759/document
https://hal.archives-ouvertes.fr/hal-01635759/file/Pelletier%202017%20Review%20%20rev2.pdf
DOI : 10.1016/j.envres.2017.06.022

Éditeur(s) : HAL CCSD
Résumé : International audience
Filamentous sulfur bacteria of the genus Beggiatoa form large mats covering the sediment in the shallow waters of a Guadeloupean mangrove (French West Indies). The abundance of these bacteria varies over the year and their trophic role may, therefore, also vary. We investigated this variation by conducting a survey examining the stable isotopic compositions of four grazers and four food sources during nine sampling sessions in three different periods of the year. We analyzed bulk isotopic compositions for each component except for the bacterial and diatom communities, for which we carried out a compound-specific 13C analysis of phospholipid-derived fatty acids (PLFAs). Correlations between isotopic compositions revealed a predominance of diatoms in the diet of nematodes and the important role of detritus and bacteria in the diet of the polychaete Ceratocephale sp. None of the grazers had an isotopic composition correlated with that of Beggiatoa suggesting that sulfur bacteria were not a predominant part of the diet of any grazer. Beggiatoa has a large central vacuole, resulting in a very low carbon content-to-volume ratio, potentially accounting for its low level of attractiveness to grazers. Mangrove sediments are habitats rich in organic carbon, in which, the addition of a food source, such as Beggiatoa, would have a limited effect on the structure of the food web over the course of the year.
Food Webs

hal-01545906
https://hal.archives-ouvertes.fr/hal-01545906
DOI : 10.1016/j.fooweb.2016.04.001

Éditeur(s) : HAL CCSD American Society for Biochemistry and Molecular Biology
Résumé : International audience
Chronic low grade inflammation is closely linked to obesity-associated insulin resistance. To examine how administration of the anti-inflammatory compound indomethacin, a general cyclooxygenase inhibitor, affected obesity development and insulin sensitivity, we fed obesity-prone male C57BL/6J mice a high fat/high sucrose (HF/HS) diet or a regular diet supplemented or not with indomethacin (±INDO) for 7 weeks. Development of obesity, insulin resistance, and glucose intolerance was monitored, and the effect of indomethacin on glucose-stimulated insulin secretion (GSIS) was measured in vivo and in vitro using MIN6 β-cells. We found that supplementation with indomethacin prevented HF/HS-induced obesity and diet-induced changes in systemic insulin sensitivity. Thus, HF/HS+INDO-fed mice remained insulin-sensitive. However, mice fed HF/HS+INDO exhibited pronounced glucose intolerance. Hepatic glucose output was significantly increased. Indomethacin had no effect on adipose tissue mass, glucose tolerance, or GSIS when included in a regular diet. Indomethacin administration to obese mice did not reduce adipose tissue mass, and the compensatory increase in GSIS observed in obese mice was not affected by treatment with indomethacin. We demonstrate that indomethacin did not inhibit GSIS per se, but activation of GPR40 in the presence of indomethacin inhibited glucose-dependent insulin secretion in MIN6 cells. We conclude that constitutive high hepatic glucose output combined with impaired GSIS in response to activation of GPR40-dependent signaling in the HF/HS+INDO-fed mice contributed to the impaired glucose clearance during a glucose challenge and that the resulting lower levels of plasma insulin prevented the obesogenic action of the HF/HS diet.
The journal of biological chemistry

hal-01063926
https://hal.archives-ouvertes.fr/hal-01063926
DOI : 10.1074/jbc.M113.525220

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Estrogen receptors (ERs) α and β are distributed in most tissues of women and men. ERs are bound by estradiol (E2), a natural hormone, and mediate the pleiotropic and tissue-specific effects of E2, such as proliferation of breast epithelial cells or protection and differentiation of neuronal cells. Numerous environmental molecules, called endocrine disrupting compounds, also interact with ERs. Phytoestrogens belong to this large family and are considered potent therapeutic molecules that act through their selective estrogen receptor modulator (SERM) activity. Using breast cancer cell lines as a model of estrogen-dependent proliferation and a stably ER-expressing PC12 cell line as a model of neuronal differentiating cells, we studied the SERM activity of major dietary compounds, such as apigenin, liquiritigenin, daidzein, genistein, coumestrol, resveratrol and zearalenone. The ability of these compounds to induce ER-transactivation and breast cancer cell proliferation and enhance Nerve Growth Factor (NGF) -induced neuritogenesis was assessed. Surprisingly, although all compounds were able to activate the ER through an estrogen responsive element reporter gene, they showed differential activity toward proliferation or differentiation. Apigenin and resveratrol showed a partial or no proliferative effect on breast cancer cells but fully contributed to the neuritogenesis effect of NGF. However, daidzein and zearalenone showed full effects on cellular proliferation but did not induce cellular differentiation. In summary, our results suggest that the therapeutic potential of phytoestrogens can diverge depending on the molecule and the phenotype considered. Hence, apigenin and resveratrol might be used in the development of therapeutics for breast cancer and brain diseases.
ISSN: 0041-008X

hal-01558816
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01558816
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01558816/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01558816/file/Lecomte%20et%20al.%20-%20Assessment%20of%20the%20potential%20activity%20of%20major%20diet.pdf
DOI : 10.1016/j.taap.2017.04.005

Éditeur(s) : HAL CCSD Royal Society of Chemistry
Résumé : International audience
Chemical mediation regulates behavioral interactions between species and thus affects population structure,community organization and ecosystem function. Among marine taxa that have developed chemicalmediation strategies, gastropods belong to a diverse group of molluscs found worldwide, including specieswith a coiled, reduced or absent shell. Most gastropods use natural products to mediate a wide range ofbehaviors such as defense, prey location or interactions with con- and hetero-geners. Their chemicallydefended diet, such as cyanobacteria, algae, sponges, bryozoans and tunicates, provides them witha considerable opportunity either as shelter from predators, or as a means to enhance their own chemicaldefense. In addition to improving their defenses, molluscs also use prey secondary metabolites in complexchemical communication including settlement induction, prey detection and feeding preferences. Theassimilation of prey secondary metabolites further provides the opportunity for interactions withconspecifics via diet-derived chemical cues or signals. This review intends to provide an overview on thesequestration, detoxification, and biotransformation of diet-derived natural products, as well as the role ofthese compounds as chemical mediators in gastropod-prey interactions.
ISSN: 0265-0568

hal-01563402
https://hal-univ-perp.archives-ouvertes.fr/hal-01563402
DOI : 10.1039/c6np00097e

Éditeur(s) : HAL CCSD American Society for Biochemistry and Molecular Biology
Résumé : International audience
Chronic low grade inflammation is closely linked to obesity-associated insulin resistance. To examine how administration of the anti-inflammatory compound indomethacin, a general cyclooxygenase inhibitor, affected obesity development and insulin sensitivity, we fed obesity-prone male C57BL/6J mice a high fat/high sucrose (HF/HS) diet or a regular diet supplemented or not with indomethacin (±INDO) for 7 weeks. Development of obesity, insulin resistance, and glucose intolerance was monitored, and the effect of indomethacin on glucose-stimulated insulin secretion (GSIS) was measured in vivo and in vitro using MIN6 β-cells. We found that supplementation with indomethacin prevented HF/HS-induced obesity and diet-induced changes in systemic insulin sensitivity. Thus, HF/HS+INDO-fed mice remained insulin-sensitive. However, mice fed HF/HS+INDO exhibited pronounced glucose intolerance. Hepatic glucose output was significantly increased. Indomethacin had no effect on adipose tissue mass, glucose tolerance, or GSIS when included in a regular diet. Indomethacin administration to obese mice did not reduce adipose tissue mass, and the compensatory increase in GSIS observed in obese mice was not affected by treatment with indomethacin. We demonstrate that indomethacin did not inhibit GSIS per se, but activation of GPR40 in the presence of indomethacin inhibited glucose-dependent insulin secretion in MIN6 cells. We conclude that constitutive high hepatic glucose output combined with impaired GSIS in response to activation of GPR40-dependent signaling in the HF/HS+INDO-fed mice contributed to the impaired glucose clearance during a glucose challenge and that the resulting lower levels of plasma insulin prevented the obesogenic action of the HF/HS diet.
ISSN: 0021-9258

hal-01074835
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01074835
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01074835/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01074835/file/JBC-2013-525220v2-Kristiansen-POSTPRINT.pdf
DOI : 10.1074/jbc.M113.525220

Éditeur(s) : HAL CCSD
Résumé : Background and objectives.[br/] Dairy propionibacteria are isolated from various ecological niches, including soil, grass, silage, rumen, raw milk and dairy plants, showing great adaptability and robustness. Used as ripening starters in Swiss type cheeses, these food grade bacteria are described as nutraceutical producers and they release into the external medium short chain fatty acids (SCFA), folic acid, cobalamin and the bifidogenic 1,4- dihydroxy-2-naphthoic acid (DHNA). These compounds are known to play a pivotal role in the modulation of intestinal physiology through diet. Considering the pro-apoptotic potential of some of these metabolites, we investigated the potential of dairy products fermented by the main species, Propionibacterium freudenreichii, to prevent colon carcinogenesis. Methods.[br/] We developed a new fermented milk. Taking advantage of milk fractions, high and stable populations of P. freudenreichii were obtained in this product. It was tested in vitro on gastric HGT-1 and colic HT-29 cells with respect to the typical hallmarks of apoptosis. In vivo, the fermented milk was evaluated in piglets with respect to general health parameters and in human microbiota-associated rats, treated or not with dimethylhydrazine (DMH), with respect to intestinal proliferation and apoptosis. Results. Fermented milk induced cell death in both gastric and colon cancer cells. Cellular and molecular characterization of cells dying in response to SCFA treatment revealed cell cycle arrest, drop in intracellular ATP, depolarization of mitochondria, translocation of key apoptosis proteins, processing of caspases and fragmentation of the nucleus. Interestingly, the new fermented milk was shown to potentiate the cytotoxic effect of molecules used in cancer chemotherapy. In accordance, it modulated expression of key apoptotic proteins. In vivo, the fermented milk was evaluated in piglets. Daily oral gavage led to high colic P. freudenreichii populations, to modulation of the intestinal microbiota and modulation of intestinal cytokines. Promotion of piglets’ growth also revealed general probiotic effects of fermented milk. Considering that propionibacteria were metabolically active in the intestine, we further investigated their impact on colon carcinogenesis (induced by dimethylhydrazine, DMH) in human microbiota-associated rats. Consumption of selected strains of propionibacteria resulted in enhanced apoptotic depletion of DMH damaged epithelial cells, yet had no effect on neither proliferation nor apoptosis in healthy rats. Conclusions and perspectives.[br/] These results open new perspectives in the field of colon cancer cells prevention and/or treatment. The synergy with pro-apoptotic chemotherapy molecules suggests that such a fermented product may be proposed as a food supplement to enhance the effects of anticancer treatments.
colloque international « Nutrition and Cancer : Hot topics from biology to public health issues »
Paris, France

hal-01190452
https://hal.archives-ouvertes.fr/hal-01190452
PRODINRA : 201853

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Humans are exposed to a large number of contaminants, many of which may have similar health effects. This paper presents a framework for identifying pollutants to be included in a cumulative risk assessment approach. To account for the possibility of simultaneous exposure to chemicals with common toxic modes of action, the first step of the traditional risk assessment process, i.e. hazard identification, is structured in three sub-steps: (1a) Identification of pollutants people are exposed to, (1b) identification of effects and mechanisms of action of these pollutants, (1c) grouping of pollutants according to similarity of their mechanism of action and health effects. Based on this exposure-based grouping we can derive "multi-pollutant" toxicity reference values, in the "dose-response assessment" step. The approach proposed in this work is original in that it is based on real exposures instead of a limited number of pollutants from a unique chemical family, as traditionally performed. This framework is illustrated by the case study of semi-volatile organic compounds in French dwellings, providing insights into practical considerations regarding the accuracy of the available toxicological information. This case study illustrates the value of the exposure-based approach as opposed to the traditional cumulative framework, in which chemicals with similar health effects were not always included in the same chemical class.
ISSN: 0013-9351

hal-00982315
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00982315
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00982315/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00982315/file/An_exposure-based_framework_for_grouping_pollutants_accepted.pdf
DOI : 10.1016/j.envres.2014.01.007

Éditeur(s) : HAL CCSD
Résumé : International audience
Increasingly, health risk assessment is addressing multiple pathway exposures to multiple contaminants. We reviewed aggregated exposure and cumulative risk approaches for contemporary and ubiquitous semivolatile organic compounds (SVOC). We identified 22 studies aggregating exposure pathways, and 31 cumulating risk. Exposure aggregation is based on the addition of pathway-specific doses, using kinetic modeling where it exists, and classic external dose equations otherwise. In most cases, exposure is dominated by a single route or source of exposure - mainly the oral pathway - via dietary or non-dietary exposure. Preferential routes and sources of exposure are influenced by SVOC physical-chemical properties such as vapor pressure. The cumulative risk approach for contaminants is based on dose addition. Simple sum of hazard quotient (Hazard Index: HI) is the most commonly used cumulative risk assessment approach, while Relative Potency Factor (RPF) appeared to the best suited - although this calls for a level of toxicological information that limits the number of compounds that can be studied simultaneously. Where both were performed, moving from HI to more refined approach produced similar results. In conclusion, both approaches - exposure aggregation and cumulative risk - rely on simple assumptions. Nevertheless, they allow uncertainty to be reduced, in comparison with source-by-source or chemical-by-chemical approaches.
Environmental Research

hal-01579608
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01579608
DOI : 10.1016/j.envres.2017.06.022
PUBMED : 28732321

Éditeur(s) : Elsevier
Résumé : Bioaccumulation is difficult to document because responses differ among chemical compounds, with environmental conditions, and physiological processes characteristic of each species. We use a mechanistic model, based on the Dynamic Energy Budget (DEB) theory, to take into account this complexity and study factors impacting accumulation of organic pollutants in fish through ontogeny. The bioaccumulation model proposed is a comprehensive approach that relates evolution of hake PCB contamination to physiological information about the fish, such as diet, metabolism, reserve and reproduction status. The species studied is the European hake (Merluccius merluccius, L. 1758). The model is applied to study the total concentration and the lipid normalised concentration of 4 PCB congeners in male and female hakes from the Gulf of Lions (NW Mediterranean sea) and the Bay of Biscay (NE Atlantic ocean). Outputs of the model compare consistently to measurements over the life span of fish. Simulation results clearly demonstrate the relative effects of food contamination, growth and reproduction on the PCB bioaccumulation in hake. The same species living in different habitats and exposed to different PCB prey concentrations exhibit marked difference in the body accumulation of PCBs. At the adult stage, female hakes have a lower PCB concentration compared to males for a given length. We successfully simulated these sex-specific PCB concentrations by considering two mechanisms: a higher energy allocation to growth for females and a transfer of PCBs from the female to its eggs when allocating lipids from reserve to eggs. Finally, by its mechanistic description of physiological processes, the model is relevant for other species and sets the stage for a mechanistic understanding of toxicity and ecological effects of organic contaminants in marine organisms.
Journal of Sea Research (1385-1101) (Elsevier), 2009-10 , Vol. 62 , N. 2-3 , P. 124-134

Droits : 2009 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2009/publication-6789.pdf
DOI:10.1016/j.seares.2009.02.006
http://archimer.ifremer.fr/doc/00000/6789/

Éditeur(s) : HAL CCSD MDPI
Résumé : International audience
Intestinal absorption and brain permeation constitute key parameters of toxicokinetics for pesticides, conditioning their toxicity, including neurotoxicity. However, they remain poorly characterized in humans. The present study was therefore designed to evaluate human intestine and brain permeation for a large set of pesticides (n = 338) belonging to various chemical classes, using an in silico graphical BOILED-Egg/SwissADME online method based on lipophilicity and polarity that was initially developed for drugs. A high percentage of the pesticides (81.4%) was predicted to exhibit high intestinal absorption, with a high accuracy (96%), whereas a lower, but substantial, percentage (38.5%) displayed brain permeation. Among the pesticide classes, organochlorines (n = 30) constitute the class with the lowest percentage of intestine-permeant members (40%), whereas that of the organophosphorus compounds (n = 99) has the lowest percentage of brain-permeant chemicals (9%). The predictions of the permeations for the pesticides were additionally shown to be significantly associated with various molecular descriptors well-known to discriminate between permeant and non-permeant drugs. Overall, our in silico data suggest that human exposure to pesticides through the oral way is likely to result in an intake of these dietary contaminants for most of them and brain permeation for some of them, thus supporting the idea that they have toxic effects on human health, including neurotoxic effects.
ISSN: 1660-4601

hal-01560242
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01560242
PUBMED : 28665355
DOI : 10.3390/ijerph14070708

Éditeur(s) : EDP Sciences
Résumé : For centuries, several species of prawns and crabs have been raised from wild-caught juveniles in coastal brackish-water fish ponds in various countries of south east Asia. The Indonesian "tambaks" are well known examples of such traditional practices. In western countries, since the turn of the century, advances of marine biology and fast increase of marine fisheries enabled the development of large-scale production and release of larval stages of American and European lobsters in a fruitless attempt to restock natural populations. After the Second World War, the increasing demand for crustaceans in United States and Japan was satisfied by opening new prawn fisheries all over the world. A major breakthrough was achieved with the development of hatchery technologies for the penaeid prawn Penaeus japonicus (Hudinaga, 1942 in Japan) and the caridean prawn Macrobrachium rosenbergii (Ling, 1969 in Malaysia), which occurred during the first decades of the second half of this century. Together with the increasing market demand in developed countries for sea food, this led to a considerable interest of both public agencies and private investors in marine shrimp and prawn culture. In western countries, a large number of pioneering commercial ventures, often based on assumptions not scientifically founded, failed. Nevertheless, the aquaculture production of prawns mainly based on wild-caught juveniles increased in South-East Asia and Central America during the 1980s. This overall positive trend should not hide important failures which occurred at a local scale, such as the Taiwanese crisis of 1988 due principally to environmental degradation, resulting in severe disease problems and a near collapse of the farming activity. Following the early period of hatchery technology development, the major scientific achievements were related to food requirements and formulation of compound diets for larvae, juveniles and adults and to a better knowledge of diseases caused by bacteria and several viruses which have been identified from hatcheries and intensive farming ponds. Additional new technological advances have emerged from recent research in the fields of physiology (endocrinology) and genetics. By far, the major part of the world production of marine crustaceans relies on penaeid prawns and, to a lesser extent, on Macrobrachium species. However, some other species of marine crustaceans have potential for aquaculture. The economic aspects of marine crustacean aquaculture should be considered together with those of the fishing industry: market prices are rather similar, depending on the quality of the product. The balance between market demand and production is an important constraint which, in turn, establishes the success of prawn farming. Since the early 1980s, crustacean aquaculture has increased tremendously in both Asia and America: the world production for 1991 approximated 700,000 tons, with more than 600,000 tons from penaeid prawn culture.
Pendant des siècles, quelques espèces de crevettes et de crabes ont été élevées à partir d'individus juvéniles capturés dans le milieu naturel, dans des bassins à poissons d'eau saumâtre de différents pays d'Asie du Sud-Est. Les « tambaks » indonésiens sont des exemples bien connus de ces pratiques traditionnelles. Dans les pays occidentaux, depuis le début du siècle, les progrès réalisés en biologie marine et la croissance rapide des pêches maritimes ont permis le développement de la production à grande échelle de stades larvaires des homards européen et américain, dans une vaine tentative de reconstitution des stocks naturels. Après la Seconde Guerre mondiale, la demande croissante des Etats-Unis et du Japon a été satisfaite par l'ouverture de nouvelles pêcheries de crevettes dans l'océan mondial. Un progrès décisif a été réalisé avec la mise au point des techniques d'écloserie pour la crevette Pénaeidé Penaeus juponicus (Hudinaga, 1942 au Japon) et la crevette Caridé Macrobrachium rosenbergii (Ling, 1969 en Malaisie), qui sont apparues au cours des premières décennies de la seconde moitié de ce siècle. Parallèlement à la demande croissante du marché des pays développés pour les produits de la mer, ce résultat s'est traduit par un intérêt considérable porté à l'élevage des crevettes marines de la part des institutions de recherche et des investisseurs. Dans les pays occidentaux, un grand nombre de tentatives d'élevage commerciales, fondées sur des considérations non scientifiquement établies, ont échoué. Néanmoins, la production aquacole de crevettes reposant sur la capture d'animaux juvéniles dans la nature, s'est développée en Asie du Sud-Est et en Amérique Centrale au cours des années 1980. Cette tendance globalement positive ne doit pas dissimuler les faillites importantes qui se sont produites à l'échelle locale, comme la crise des élevages de Taiwan en 1988, causée principalement par une dégradation de l'environnement, entraînant l'apparition de problèmes pathologiques sévères et une disparition presque totale de l'activité d'élevage. Après la période pionnière du développement de la technologie d'écloserie, les principaux acquis scientifiques concernent les besoins alimentaires et la formulation d'aliments composés pour les larves, les jeunes et les adultes, et une meilleure connaissance des maladies bactériennes et virales qui interviennent dans les écloseries et les fermes d'élevage intensif. De nouveaux progrès techniques complémentaires ont vu le jour à la suite de recherches dans les domaines de la physiologie (endocrinologie) et de la génétique. De loin, la majeure partie de la production mondiale de Crustacés marins repose sur les crevettes Pénaeidés et, dans une moindre mesure, sur des espèces de Macrobrachium. Cependant, quelques autres espèces de Crustacés marins intéressent potentiellement l'aquaculture. Les aspects économiques de l'aquaculture de crustacés marins doivent être considérés avec ceux de l'industrie des pêches maritimes : les prix du marché sont à peu près les mêmes, et dépendent de la qualité du produit. Le rapport entre la demande du marché et la production est une contrainte importante qui à son tour, détermine les conditions du succès de l'élevage de crevettes. Depuis le début des années 1980, l'aquaculture de crustacés a augmenté considérablement en Asie et en Amérique : la production mondiale pour 1991 avoisine 700 000 tonnes, avec plus de 600 000 tonnes provenant des élevages de crevettes Pénaeidés.
Aquatic Living Resources (0990-7440) (EDP Sciences), 1993-10 , Vol. 6 , N. 4 , P. 319-329

Droits : IFREMER-Gauthier-Villars, 1993
http://archimer.ifremer.fr/doc/00190/30119/28587.pdf
DOI:10.1051/alr:1993033
http://archimer.ifremer.fr/doc/00190/30119/