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International audience; To reduce the exposure of the French West Indies population to the organochlorine insecticide chlordecone (Kepone; CLD), the contamination of currently consumed foodstuffs must be reduced. Depuration of contaminated animals before slaughter could be a strategy to obtain safe animal products. The aim of this study was to characterize and quantify CLD elimination in contaminated ewes during depuration process. Experiments A and B consisted in a single intravenous (i.v.) administration of CLD (n = 5) and CLDOH (chlordecol; n = 3) followed by a 84-d and 3-d depuration period respectively with collection of blood, faeces and urine samples. After CLD administration, CLD and conjugated-CLDOH (CLDOH-C) were quantified in serum and urine and CLD and CLDOH were quantified in faeces. Based on calculations of faecal, urinary and body clearances of CLD and CLDOH-C, faeces appeared as the major route of CLD excretion with 86 % of the CLD administered dose eliminated in faeces, either as CLD (51 %) or as CLDOH (35 %).

This work aims to valorize an invasive brown macroalga (Sargassum spp. consisting of two species Sargassum fluitans and Sargassum natans) by producing biochars (BCs) and activated carbons (ACs). Its abundant and frequent occurrence along the Caribbean coastlines, Florida, Gulf of Mexico during the last past nine years, have triggered human health concerns and have negatively impacted local economy, ecology and the environment. In this paper, BCs and ACs were developed to assess the reduction of chlordecone (CLD) environmental availability in artificial and tropical contaminated soils. Such innovative approach was proposed to limit CLD bio-availability to fauna and outdoor reared-animals. The BCs were prepared by pyrolysis at 700 °C while ACs samples by chemical or physical activation. Textural characterization, has evidenced that bi-modal structures with micro- and mesopores, various surface and high pore volumes were successfully obtained. Finally, the environmental availability tests resulted in various ability of BCs or ACs to significantly sequestrate CLD on artificial contaminated soils and on a natural nitisol. In particular, the BCs prepared with a 3 h pyrolysis time, exhibited the highest porosities properties and was the best candidate to efficiently sequestrate CLD in soil samples.

International audience; Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants originating from incomplete combustion processes. Humans are mainly exposed through contaminated food ingestion. PAHs are neurotoxic compounds both for human and rodents, and may be found in placenta, umbilical cord blood and breast milk, suggesting that early exposure may impact developing central nervous system. In a previous study we showed that PAH exposure during both gestation and lactation periods in rats increased anxiety-related behaviours and decreased cerebral metabolism in several key structures linked to the limbic system on male pups at the adult stage. The aim of the present study was to assess the effects of an exclusive gestational PAH exposure on the same aspects of brain functionality. Female rats were exposed through diet to a 16 PAH mixture at doses of 2 mu g/kg/day or 200 mu g/kg/day during gestation. Late neurotoxic effects were evaluated by carrying out behavioural and cognitive tests and histochemical analyses using cytochrome oxidase activity as a cerebral metabolism marker in different brain areas. The results of this study revealed that behaviour and cerebral metabolism on prenatally PAH exposed adult rats was not significantly affected by the exposure to these pollutants. Finally this work highlights that the exposure period to pollutants such as PAHs at very early stages of development play a key role on the neurological impairment induced. (C) 2013 Elsevier Ireland Ltd. All rights reserved.

International audience; Little is known in terms of multi-matrix cytochrome P450 activity induction under repeated oral exposure to planar halogenated and polycyclic aromatic hydrocarbons (PHH, PAH). In the present study, 60 rats were daily exposed, during 28 days, to oral ingestion of a mixture consisting of phenanthrene, pyrene and benzo(a)pyrene at 0, 6 or 600 mu g/day. EROD activity, reflecting almost exclusively CYP1A1 and CYP1B1 activities, was measured in brain and liver microsomes as well as in peripheral blood lymphocytes (PBLs). All induction kinetics could be appropriately fitted using logistic-like models. After 28 days of exposure to a 6 mu g/day dose, EROD activity was found to be 91, 152 and 94-fold increased in lymphocytes, liver and brain, respectively, compared to day 0. Plateau activities could be appropriately fitted versus ingested doses using Hill or Michaelis-Menten models. Correlations between matrices made it possible to conclude that EROD activity in PBL should be considered as a sensitive, convenient and non-destructive approach for (i) evaluating EROD activity in liver, which was found to represent 98% of the observed EROD activities in the three tested matrices and (ii) evaluating oral exposure of homogeneous groups of farm animals (race, diet) to CYP inducing PAH and PHH.

The aim of this work was to characterize phenanthrene, pyrene, benzo(a)pyrene and TCDD transfer to milk, urine and faeces in lactating goats after a single oral ingestion (2.5 10 6 Bq ) of [ 14 C ] phenanthrene , [ 14 C ] pyrene , [ 14 C ] benzo[a]pyrene or [ 14 C ] 2,3,7,8-TCDD. Seven hours after [ 14 C ] PAHs oral ingestion, a radioactivity peak was detected in plasma for all compounds studied. Regarding excretion routes, three specific types of behaviour were noticed: 2,3,7,8-TCDD was mainly excreted in milk (7.8%) and a large part of radioactivity ingested remained in the organism (71.2%). Phenanthrene and pyrene presented a similar behaviour, with a low milk transfer (1.6% and 1.9%, respectively) and a high excretion through urine (40.4% and 11.4%, respectively) suggesting their metabolization. Benzo[a]pyrene was poorly absorbed (88% of the ingested part of this compound was detected in faeces) and radioactivity due to benzo[a]pyrene was not significantly detected in milk (0.2%).

Three rumen cannulated lactating goats fitted with a temporary polyvinyl intravenous catheter were used to study [14C] incorporation in milk proteins (casein (CN), whey proteins (WP)) in comparison with incorporation in lactose (LAC) and in milk fat (MF) after a single ruminal supply of d -[U-14C]glucose ([14C]GLU) (9.2 MBq/goat). Rumen fluid and venous blood samples were collected at 0.5 h, 1 h, 1.5 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 24 h, 36 h, 48 h, 60 h, 72 h, and 84 h; and milk samples were taken at 6 h, 12 h, 24 h, 36 h, 48 h, 60 h, 72 h, and 84 h after the tracer administration. As expected, radioactivity followed a logarithmic decline in total rumen fluid. In plasma and in milk, highest [14C] labelling was observed at 0.5 h and 6 h, respectively. [14C]-enrichment curves in CN, in WP, in LAC and in MF were similar and the measured radioactivity levels were in the same range. [14C]-labelling peak was observed either at the first milking for LAC (3750 mBq/mg C), for CN (2048 mBq/mg C) and for WP (1334 mBq/mg C), or at the second milking for MF (2101 mBq/mg C). Approximately 1% of the ruminal-administered radioactivity was found in milk proteins. Recovery in milk proteins was similar to recovery in MF and represented about 30% of radioactivity obtained in LAC. Thus, end products of glucose metabolism in the rumen are used in relatively high amounts for protein synthesis. Further experiments should now be carried out to specify the associated biochemical pathways.

International audience; Fluorene is a volatile polycyclic aromatic hydrocarbon (PAH) with an airborne concentration ranging a level of 5 ng/m3. Since no data on fluorene neurotoxicity are available, a study on adult rats was conducted in order to evaluate the neurobehavioural effects of a repeated inhalation exposure. For that, male rats (n = 12/group) were exposed nose-only to 1.5 (10_g/m3) or 150 (1mg/m3) ppb of fluorene 6 h/day for 14 consecutive days, while control animals were exposed to a non-contaminated air. At the end of the period of exposure, animals were tested for spontaneous activity in the open-field, for anxiety in the elevated plus maze, for short term memory in the Y maze and for spatial learning in the eight arm maze. After this exposure, no differences were observed in body and brain weights, whereas a significant decrease of the weight of the liver was measured in fluorene-exposed rats compared to controls. In the open-field, a significant increase in the number of crossed cases and the time spent in the central area of the maze was observed in rats exposed to fluorene. For the same animals, in the elevated plus maze, the times spent in the central place and in the closed arm were respectively significantly higher and lower than controls. Taken together, these results are indicative of a reduction of anxiety in rats exposed to fluorene compared to controls. Learning and memory performances remained unaffected. Otherwise, the weight of the surrenal gland, the blood levels of corticosterone and both depression-related behaviour in the forced swimtest indicated that the restraint stress induced by the model of exposure did not contribute to the effects of fluorene. In conclusion, these results are indicative of the neurotoxicity of fluorene and confirm the possible risk induced by an environmental contamination with PAHs.

International audience

International audience; Organic pollutants like PAHs, PCDD/Fs and PCBs can be transferred to the milk of lactating goats after an oral contamination. This study focused on the effects of an oral chronic administration of milk issued from these goats on brain metabolism and behaviour in adult rats. Four groups of rats (n = 12) were treated with methylcellulose 0.3% (MC), non-contaminated milk (NCGM), contaminated milk with PAHs or with a PCDD/F-PCB mixture (PCM). MC or milk were daily administrated during 3 weeks (0.5 ml/100 g bw, p.o.). At the end of the treatment, rats were studied for their locomotor, spatial memory and anxiety performances in an open-field, a T maze and an elevated plus maze (EPM), respectively. Thus, the animals were sacrificed, the brain removed and the tissue analyzed for fingerprinting using the 1H NMR spectroscopy. Urine samples were also collected once a week over the treating period. The multivariate statistical analysis of the 1H NMR spectra of urine discriminated PAH- and PCM-treated animals from controls (MC, NCGM) after 3 weeks of treatment. At the same time, PAH-treated rats exhibited a reduction of the anxiety-related behaviour in the EPM and deficits of spontaneous alternation in the T maze whereas the PCM animals did not. In the brain, PAHs and PCM induced metabolic deviations compared to controls, but these perturbations were different between the two contaminated groups. These results suggest differences in the neurotoxicity of xenobiotics from one group of pollutants to another, and question the toxicity of these compounds through ingestion of contaminated food.