Use and storage of pesticides at home in France (the Pesti'home survey 2014).

Some epidemiological studies have raised health concerns following the chronic exposure of pregnant women and children to pesticides in the domestic environment. In France very little is known about potential exposure to pesticides at home. An observational study called Pesti'home was carried out in continental France between July and November 2014. The residential use of pesticides was investigated and an inventory of pesticides and active ingredients used and stored at home was drawn up. Plant protection products, biocides, and human and animal external pest control products were listed during face-to-face interviews. A random sample of households including at least one adult (18-79 years old) was selected following a two-stage stratified random sampling method using the national census database. Within each household, an adult was appointed to answer survey questions. Data related to the interviewee's sociodemographic and housing characteristics, the reported use of pesticides at home, and a visual inventory of all stored pesticides were collected. Overall, 1507 households participated. The participation rate was between 36% and 57% according to the definition chosen. Over the previous 12 months, 75% of households declared that they had used at least one pesticide. Households who used and stored at least one product most frequently used an insecticide (84%). The active ingredients most frequently used by these households as insecticides were pyrethroids, namely tetramethrin and permethrin. The Pesti'home survey collected detailed data on the residential use of pesticides for risk assessment at national and European levels.

Aggregate exposure of the adult French population to pyrethroids.

The French Nutrition and Health Survey (ENNS) reported higher biomarker levels of exposure to pyrethroids than those observed in North American and German biomonitoring studies. The authors therefore investigated aggregate exposure to permethrin as an initial case study because this compound is one of the most widely-used pyrethroid insecticides. We assessed several contamination sources-such as indoor and outdoor air, settled dust and diet-and several pathways, including oral, inhalation and dermal routes. We used permethrin exposure level estimations (computed from ENNS data) and a PBPK model calibrated with human kinetic data (from 6 individuals) to simulate an internal dose of cis- and trans-3-(2,2 dichlorovinyl)-2,2-dimethyl-(1-cyclopropane) carboxylic acid (cis- or trans-DCCA) in a population of 219 individuals. The urinary concentrations of cis- and trans -DCCA predicted by the PBPK model according to three permethrin exposure scenarios ("lower", "intermediate", and "upper"), were compared to the urinary levels measured in the ENNS study. The ENNS levels were between the levels simulated according to permethrin exposure scenarios "lower" and "intermediate". The "upper" scenario led to an overestimation of the predicted urinary concentration levels of cis - and trans -DCCA compared to those measured in the ENNS study. The most realistic scenario was the "lower" one (permethrin concentration of left-censored data considered as 0). Using PBPK modeling, we estimated the contribution of each pathway and source to the internal dose. The main route of permethrin exposure was oral (98%), diet being the major source (87%) followed by dust (11%) then the dermal route (1.5%) and finally inhalation (0.5%).

Environmental Exposure of the Adult French Population to Permethrin.

This work aims to assess the exposure to permethrin of the adult French population from available contamination measurements of outdoor air, indoor air, and settled dust. Priority is given to the assessment of chronic exposure, given the potential of permethrin to induce cancers and/or endocrine disorders. A statistical method was devised to calculate exposure to permethrin by different pathways (inhalation, indirect dust ingestion, and dermal contact). This method considers anthropometric parameters, the population's space-time budget, and recent methods for calculating dermal exposure. Considering the media of interest, our results pointed to house dust as the main environmental source of permethrin exposure, followed by indoor and outdoor air. Dermal contact and indirect dust ingestion may be more important exposure pathways than inhalation. A sensitivity analysis indicated that exposure estimates were mainly affected by variability within contamination data. This study is the first step in aggregated exposure and risk assessment due to pyrethroid exposure. Outdoor air, indoor air, and settled dust may constitute significant exposure sources, in addition to diet, which could be important. The next step entails assessing internal doses and estimating the proportion of each exposure source and pathway relative to internal exposure.

Polychlorobiphenyls in freshwater fish: a new strategy to set maximum contamination limits.

Polychlorinated biphenyls (PCBs) are persistent organic pollutants accumulating along the food chain, and particularly in fish. Consequently, the European Commission has set regulatory limits for PCBs in both sea- and freshwater fish. Focusing on freshwater fish, the French Agency for Food Environmental and Occupational Health & Safety has developed a method to determine the areas in France where the consumption of locally caught freshwater fish is not recommended due to PCB contamination. To determine these areas of potential health concern, an existing statistical model of the relationship between the consumption of local fish by freshwater anglers and their PCB body burden is linked to a newly determined critical PCB body burden threshold for the population. The main conclusions of this study are that the consumption of two freshwater fish per week from rivers in the areas of France where the median contamination level in fish is greater than 250 ng g-1 could lead to some exceedance of the critical body burden threshold.

The Replacement of 10 Non-Conserved Residues in the Core Protein of JFH-1 Hepatitis C Virus Improves Its Assembly and Secretion.

Hepatitis C virus (HCV) assembly is still poorly understood. It is thought that trafficking of the HCV core protein to the lipid droplet (LD) surface is essential for its multimerization and association with newly synthesized HCV RNA to form the viral nucleocapsid. We carried out a mapping analysis of several complete HCV genomes of all genotypes, and found that the genotype 2 JFH-1 core protein contained 10 residues different from those of other genotypes. The replacement of these 10 residues of the JFH-1 strain sequence with the most conserved residues deduced from sequence alignments greatly increased virus production. Confocal microscopy of the modified JFH-1 strain in cell culture showed that the mutated JFH-1 core protein, C10M, was present mostly at the endoplasmic reticulum (ER) membrane, but not at the surface of the LDs, even though its trafficking to these organelles was possible. The non-structural 5A protein of HCV was also redirected to ER membranes and colocalized with the C10M core protein. Using a Semliki forest virus vector to overproduce core protein, we demonstrated that the C10M core protein was able to form HCV-like particles, unlike the native JFH-1 core protein. Thus, the substitution of a few selected residues in the JFH-1 core protein modified the subcellular distribution and assembly properties of the protein. These findings suggest that the early steps of HCV assembly occur at the ER membrane rather than at the LD surface. The C10M-JFH-1 strain will be a valuable tool for further studies of HCV morphogenesis.

Study on polychlorobiphenyl serum levels in French consumers of freshwater fish.

INTRODUCTION: Polychlorobiphenyls (PCBs) are persistent pollutants that are widespread in the environment and in foodstuffs, particularly in freshwater fish, which frequently exceed the maximum levels set by European regulations. OBJECTIVES: First, we describe the consumption of freshwater fish and serum PCB levels in French anglers, a population expected to have the highest level of dietary PCB exposure. Second, we investigated whether there is a statistical relationship between serum PCB levels and the angler consumption of freshwater fish with high PCB bioaccumulation potential (PCB-BP(+) freshwater fish) in order to make recommendations with regard to safe consumption of freshwater fish. METHODS: We conducted a survey of anglers from six sites with contrasting PCB contamination levels. The survey included a food consumption frequency questionnaire and blood samples were taken to assess serum PCB levels. We used a regression model to determine the main factors contributing to serum PCB levels. RESULTS: Consumption of PCB-BP(+) freshwater fish was relatively infrequent. Serum PCB levels of the study population and of women of childbearing age were in the same range as those observed in the French population and in neighbouring European countries, but higher than in the North American population. The two factors with the highest positive association with serum PCB levels were age (R(2)=61%) and the consumption of PCB-BP(+) freshwater fish (R(2)=2%). Using the regression model, we calculated, for several scenarios depending on the age and gender of the population, the maximum annual frequencies for PCB-BP(+) freshwater fish consumption that do not exceed the critical body burden threshold. CONCLUSION: Following the results of this study, the French agency for food, environmental and occupational health and safety (ANSES) issued an opinion and recommended some specific maximum freshwater fish consumption frequencies to protect the French general population.

Cumulative dietary exposure to a selected group of pesticides of the triazole group in different European countries according to the EFSA guidance on probabilistic modelling.

The practicality was examined of performing a cumulative dietary exposure assessment according to the requirements of the EFSA guidance on probabilistic modelling. For this the acute and chronic cumulative exposure to triazole pesticides was estimated using national food consumption and monitoring data of eight European countries. Both the acute and chronic cumulative dietary exposures were calculated according to two model runs (optimistic and pessimistic) as recommended in the EFSA guidance. The exposures obtained with these model runs differed substantially for all countries, with the highest exposures obtained with the pessimistic model run. In this model run, animal commodities including cattle milk and different meat types, entered in the exposure calculations at the level of the maximum residue limit (MRL), contributed most to the exposure. We conclude that application of the optimistic model run on a routine basis for cumulative assessments is feasible. The pessimistic model run is laborious and the exposure results could be too far from reality. More experience with this approach is needed to stimulate the discussion of the feasibility of all the requirements, especially the inclusion of MRLs of animal commodities which seem to result in unrealistic conclusions regarding their contribution to the dietary exposure.

Perfluoroalkyl acid contamination and polyunsaturated fatty acid composition of French freshwater and marine fishes.

In this study, French marine and freshwater fish perfluoroalkyl acid (PFAA) contamination are presented along with their fatty acid (FA) composition to provide further elements for a risk/benefit balance of fish consumption to be assessed. The 29 most consumed marine fish species were collected in four metropolitan French coastal areas in 2004 to constitute composite samples. Geographical differences in terms of consumed species and contamination level were taken into account. Three hundred and eighty-seven composite samples corresponding to 16 freshwater fish species collected between 2008 and 2010 in the six major French rivers or their tributaries were selected among the French national agency for water and aquatic environments freshwater fish sample library. The raw edible parts were analyzed for FA composition and PFAA contamination. Results show that freshwater fishes are more contaminated by PFAAs than marine fishes and do not share the same contamination profile. Freshwater fish contamination is mostly driven by perfluorooctane sulfonate (PFOS) (75%), whereas marine fish contamination is split between perfluorooctanoic acid (PFOA) (24%), PFOS (20%), perfluorohexanoic acid (PFHxA) (15%), perfluoropentanoic acid (PFHpA) (11%), and perfluorobutanoic acid (PFBA) (11%). Common carp, pike-perch, European perch, thicklip grey mullet, and common roach presented the most unfavorable balance profile due to their high level of PFAAs and low level of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs). These data could be used, if needed, in an updated opinion on fish consumption that takes into account PFAA contamination.

Towards the definition of a core of microorganisms involved in anaerobic digestion of sludge.

The microbial consortium involved in anaerobic digestion has not yet been precisely characterized and this process remains a 'black box' with limited efficiency. In this study, seven anaerobic sludge digesters were selected based on technology, type of sludge, process and water quality. The prokaryotic community of these digesters was examined by constructing and analysing a total of 9890 16S rRNA gene clones. Libraries were constructed using primers specific for the Bacteria and Archaea domains for each digester, respectively. After phylogenetic affiliation, the libraries were compared using statistical tools to determine the similarities or differences among the seven digesters. Results show that the prokaryotic community of an anaerobic digester is composed of phylotypes commonly found in all anaerobic digesters sampled and also of specific phylotypes. The Archaea community is represented by an equilibrium among a restricted number of operational taxonomic units (OTUs). These OTUs are affiliated with Methanosarcinales, Methanomicrobiales and Arc I phylogenetic groups. Statistical analysis revealed that the Bacteria community can be described as a three component model: one-third making up a core group of phylotypes common to most of the digesters, one-third are phylotypes shared among a few digesters and another one-third are specific phylotypes. The core group is composed of only six OTUs affiliated with Chloroflexi, Betaproteobacteria, Bacteroidetes and Synergistetes. Its role in anaerobic degradation appears critical to investigate. This comparison of anaerobic digester populations is a first step towards a future understanding of the relationship among biodiversity, operating conditions and digester efficiency.