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7th International Workshop on Chemical Bioavailability in the Terrestrial Environment, 3-6 November 2013, Notingham, England; International audience; The application of chlordecone (CLD), a chlorinated polycyclic ketone pesticide, until 1993 in the French West Indies has resulted in long-term pollution of agricultural soils (10% of them exceed 1 mg kg(-1)). The aim of this study was to assess the impact of two tropical volcanic soils, an andosol and a nitisol, on CLD availability in piglets, using the relative bioavailability (RBA) approach For both soils and relative to an oil matrix, RBA was close to 100%, indicating that CLD was not retained in the soil matrices during the piglet digestive process. Additionally, after a 14 day exposure period, liver and subcutaneous fat CLD concentrations exceeded the maximum residue limit (10 mu g kg(-1) of fresh matter and 100 mu g kg(-1) of fat for liver and subcutaneous fat, respectively) beyond a CLD ingestion of 2.1 and 6.8 mu g CLD kg(-1) of body weight per day, respectively. Thus, rearing practices in CLD-contaminated areas should avoid involuntary soil ingestion by farm animals.

International audience; This study investigated milk excretion kinetics of PCBs, tetra-BDE (BDE 47), and penta-BDE (BDE 99) in goats exposed to contaminated soil under controlled conditions. The animals were fed (80 days) with feed containing 5% of contaminated soil. During this exposure period, milk was analyzed weekly. At the end of the experiment the PCBs and PBDEs retained in hepatic and adipose tissues were also determined. The soil-milk carry over rates (CORs) of PCBs ranged from 6 to 62%. This result suggests that a large part of ingested soil-bound PCBs was recovered in milk. Significantly different levels between the congeners were reported in the tissues (fat, liver). BDE 47 and 99 excretions in milk achieved a plateau after 2 weeks of exposure, and their corresponding CORs were about 30%. These two congeners showed a significantly (P < 0.05) lower accumulation in the adipose tissue than the major PCB congeners. The concentrations of BDE 47 and 99 in the liver were the same as PCB concentrations. This result suggests that the low brominated congeners are submitted to the metabolism more extensively than the major PCBs.

International audience; Urinary 1-hydroxypyrene (1-OH-pyrene) is now largely considered to be a valuable biomarker of exposure of man and animals to pyrene and other polycyclic aromatic hydrocarbons (PAHs). However, from a practical and agronomic standpoint, the question remains whether such biomarking capability still holds when 1-OH-pyrene is analyzed in milk produced by ruminants. To assess this hypothesis, four goats were daily submitted to three different amounts of pyrene oral ingestion, together with phenanthrene and benzo(a)pyrene (1, 7, and 49 mg/day during 1 week each). An HPLC−fluorometric analysis of 1-OH-pyrene in milk revealed a perfect correlation between pyrene doses and 1-OH-pyrene detected in milk, thus fully confirming the biomarking capability of 1-OH-pyrene and providing information on its transfer coefficient toward milk. Transfer equations such as the ones found in the present study could be used as a valuable and practical risk assessment tool in (i) the accurate monitoring of exposure of ruminants to pyrene and (ii) the evaluation of occupational and environmental exposure of ruminants to PAH mixtures.

International audience; Ruminants, which have a central place in the food chain, ingest soil that may contain pollutants. The bioaccessibility of three different polycyclic aromatic hydrocarbon compounds from soil was studied using an in vitro model based on the digestive tract of cows. For this purpose, pasture soil was spiked with 14C radio-labeled compounds, aged, and then exposed to conditions which simulated the digestive compartments of the rumen, abomasum, and intestines. Our results show that aging generally reduced the bioaccessibility of all the compounds tested. Total bioaccessibilty in the first digestive compartment, i.e., the rumen, depended on the considered compound: elevated for phenanthrene (17–24%), moderate for pyrene (6.6–8.1%), and low for benzo[a]pyrene (2.3–3.6%). Bioaccessibility was very low in abomasal acidity (generally