Fanny Héraud

Assessment of dietary exposure of nitrate and nitrite in France

The aim of this study was to assess the dietary exposure of nitrate and nitrite in France. A total of 13, 657 concentration levels of nitrate and nitrite measured in food, representing 138 and 109 food items, respectively, and coming from French monitoring programmes between 2000 and 2006, were used. Depending on the non-detected and non-quantified analysis treatment, lower and upper concentration mean estimates were calculated for each food item. These were combined with consumption data derived from 1474 adults and 1018 children from the French national individual consumption survey (INCA1), conducted in 1999 and based on a 7-day food record diary. A total of 18% of spinaches, 6% of salads, 10% of cheeses, 8% of meat products and 6% of industrial meat products exceeded the European nitrate maximum level or maximum residual level. A total of 0.4% of industrial meat products and 0.2% of meat products exceeded their European nitrite maximum level or maximum residual level. Nitrate dietary exposure averaged 40% of the acceptable daily intake (ADI; 3.7 mg kg−1 body weight day−1) for adults and 51 − 54% of the ADI for children with the major contributors being, for adults and children, respectively, vegetables (24 and 27% of ADI), potatoes (5 and 11% of ADI), and water (5 and 5% of ADI). The individual nitrate dietary intake of 1.4% (confidence interval (CI95th) [0.8; 2.0]) to 1.5% (CI95th [0.9; 2.1]) of adults and 7.9% (CI95th [6.2; 9.6]) to 8.4% (CI95th [6.7; 10.1]) of children were higher than the ADI. Nitrite dietary exposure averaged 33–67% of the ADI (0.06 mg kg−1 body weight day−1) for adults and 67–133% of the ADI for children, with contributions of additive food vectors at 33% of ADI for adults and 50–67% of ADI for children. The individual nitrite dietary intake of 0.7% (CI95th [0.3; 1.1]) to 16.4% (CI95th [14.5; 18.3]) of adults and 10.5% (CI95th [8.6; 12.4]) to 66.2% (CI95th [63.3; 69.1]) of children were higher than the ADI.

Pesticide exposure of pregnant women in Guadeloupe: Ability of a food frequency questionnaire to estimate blood concentration of chlordecone

CONTEXT Chlordecone, an environmentally persistent organochlorine insecticide used intensively in banana culture in the French West Indies until 1993, has permanently polluted soils and contaminated foodstuffs. Consumption of contaminated food is the main source of exposure nowadays. We sought to identify main contributors to blood chlordecone concentration (BCC) and to validate an exposure indicator based on food intakes. MATERIAL AND METHODS We used a food frequency questionnaire (FFQ) completed by a sample of 194 pregnant women to estimate their dietary exposure to chlordecone and compared it to blood levels. In a first approach, chlordecone daily intake was estimated as the product of daily eaten quantity of 214 foodstuffs, multiplied by their chlordecone content, and summed over all items. We then predicted individual blood chlordecone concentration with empirical weight regression models based on frequency of food consumption, and without contamination data. RESULTS Among the 191 subjects who had BCC determination, 146 (76%) had detectable values and mean BCC was 0.86 ng/mL (range < LOD-13.2). Mean per capita dietary intake of chlordecone was estimated at 3.3 microg/day (range: 0.1-22.2). Blood chlordecone levels were significantly correlated with food exposure predicted from the empirical weight models (r=0.47, p<0.0001) and, to a lesser extent, with chlordecone intake estimated from food consumption and food contamination data (r=0.20, p=0.007). Main contributors to chlordecone exposure included seafood, root vegetables, and Cucurbitaceous. CONCLUSION These results show that the Timoun FFQ provides valid estimates of chlordecone exposure. Estimates from empirical weight models correlated better with blood levels of chlordecone than did estimates from the dietary intake assessment.

Quantitative Risk Assessment Relating to Adventitious Presence of Allergens in Food: A Probabilistic Model Applied to Peanut in Chocolate

Peanut allergy is a public health concern, owing to the high prevalence in France and the severity of the reactions. Despite peanut-containing product avoidance diets, a risk may exist due to the adventitious presence of peanut allergens in a wide range of food products. Peanut is not mentioned in their ingredients list, but precautionary labeling is often present. A method of quantifying the risk of allergic reactions following the consumption of such products is developed, taking the example of peanut in chocolate tablets. The occurrence of adventitious peanut proteins in chocolate and the dose-response relationship are estimated with a Bayesian approach using available published data. The consumption pattern is described by the French individual consumption survey INCA2. Risk simulations are performed using second-order Monte Carlo simulations, which separately propagates variability and uncertainty of the model input variables. Peanut allergens occur in approximately 36% of the chocolates, leading to a mean exposure level of 0.2 mg of peanut proteins per eating occasion. The estimated risk of reaction averages 0.57% per eating occasion for peanut-allergic adults. The 95% values of the risk stand between 0 and 3.61%, which illustrates the risk variability. The uncertainty, represented by the 95% credible intervals, is concentrated around these risk estimates. Children have similar results. The conclusion is that adventitious peanut allergens induce a risk of reaction for a part of the French peanut-allergic population. The method developed can be generalized to assess the risk due to the consumption of every foodstuff potentially contaminated by allergens.

The PERICLES research program: An integrated approach to characterize the combined effects of mixtures of pesticide residues to which the French population is exposed

Due to the broad spectrum of pesticide usages, consumers are exposed to mixtures of residues, which may have combined effects on human health. The PERICLES research program aims to test the potential combined effects of pesticide mixtures, which are likely to occur through dietary exposure. The co-exposure of the French general population to 79 pesticide residues present in the diet was first assessed. A Bayesian nonparametric model was then applied to define the main mixtures to which the French general population is simultaneously and most heavily exposed. Seven mixtures made of two to six pesticides were identified from the exposure assessment. An in vitro approach was used for investigating the toxicological effects of these mixtures and their corresponding individual compounds, using a panel of cellular models, i.e. primary rat and human hepatocytes, liver, intestine, kidney, colon and brain human cell lines. A set of cell functions and corresponding end-points were monitored such as cytotoxicity, real-time cell impedance, genotoxicity, oxidative stress, apoptosis and PXR nuclear receptor transactivation. The mixtures were tested in equimolar concentrations. Among the seven mixtures, two appeared highly cytotoxic, five activated PXR and depending on the assay one or two were genotoxic. In some experiments, the mixture effect was quantitatively different from the effect expected from the addition concept. The PERICLES program shows that, for the most pesticides mixtures to which the French general population is exposed, the toxic effects observed on human cells cannot be easily predicted based on the toxic potential of each compound. Consequently, additional studies should be carried on in order to more accurately define the mixtures of chemicals to which the consumers are exposed, as well as to improve the investigation, prediction and monitoring of their potential human health effects.

Impact of food consumption habits on the pesticide dietary intake: Comparison between a French vegetarian and the general population

This study aims to compare the pesticide residue dietary intake of the French general population and the vegetarian population, separated into five specific diets: omnivorous (OMN), lacto-vegetarian (LV), ovo-lacto-vegetarian (OLV), pesco-lacto-vegetarian (PLV) and vegan (VG). Theoretical Maximum Daily Intakes (TMDIs) based on Maximum Residue Levels (MRLs) were calculated as a percentage of the Acceptable Daily Intake (ADI). Among the 421 pesticides studied, only 48 had TMDI above ADI for at least one population subgroup. An excessive exposure was noticed for 44, 43, 42, 41 and 30 pesticides in the OLV, VG, OMN, LV and PLV groups, respectively, versus 29 in the general population. Meat and egg products consumption was responsible for higher intakes of organochlorine pesticides in the general population than in the vegetarian population (TMDI = 348% versus 146–183% ADI for aldrin). However, as the limited consumption of animal-origin commodities was largely offset by a higher fruit, vegetable and cereal intake in the vegetarian diets, vegetarians appear to be preferentially exposed to pesticides, for which fruit, vegetables and cereals are the main contributors, such as tri-allate, chlorpyrifos-methyl and diazinon. This study illustrates that consumption habits have a real impact on pesticide exposure in terms of intake levels, number and type of pesticides, representing a potential risk of dietary exposure. Except for organochlorine compounds, the vegetarian population may be more exposed to pesticide residues than the general population due to specific dietary habits. Thus, this population should be considered for risk assessment of pesticide residues.

In-house validation for analytical methods and quality control for risk evaluation of chlordecone in food

Chlordecone was used until 1993 as a pesticide in the banana plantation of Martinique and Guadeloupe (French Antilles) against the root borer. This organochlorine pesticide was lipophilic, remnant, and toxic for human beings with both acute and chronic effects. Chlordecone was strongly absorbed and stored in soil and weakly decomposed in environment. Surveys conducted in 2001 revealed its presence in soil, rivers, and domestic food products. Local food (fruits and vegetables, cattle, poultry, and fish) was growing on soils, widely contaminated by chlordecone, used in the past as banana plantations. In 2003, French Administration asked for a risk evaluation for the Antilles population. The French Agency for Food Safety, proposed a Provisional Tolerable Daily Intake of 0.0005 mg kg−1 b.w. day−1, and an Acute Reference Dose of 0.01 mg kg−1 b.w. day−1, based on a toxicological risk assessment. The French National Reference Laboratory for pesticides has carried out two analytical methods, one for food of animal origin and another for food of fruit and vegetable origin. These methods were validated in the reference laboratory and dispatched to 13 laboratories for a proficiency test before the launch of two studies on Martinique and Guadeloupe food. About 900 samples from Martinique were sent to the network of laboratories for analysis of chlordecone. Performance parameters obtained through the proficiency test were briefly reported. The quality control test proposed in this study was discussed to shed light on the true variability achievable by intra-laboratory and inter-laboratory analysis. The limits of conventional quality-control procedures were discussed, and a process was proposed in order to get better confidence in analytical results.

Identification of the main pesticide residue mixtures to which the French population is exposed

Owing to the intensive use of pesticides and their potential persistence in the environment, various pesticide residues can be found in the diet. Consumers are therefore exposed to complex pesticide mixtures which may have combined adverse effects on human health. By modelling food exposure to multiple pesticides, this paper aims to determine the main mixtures to which the general population is exposed in France. Dietary exposure of 3337 individuals from the INCA2 French national consumption survey was assessed for 79 pesticide residues, based on results of the 2006 French food monitoring programmes. Individuals were divided into groups with similar patterns of co-exposure using the clustering ability of a Bayesian nonparametric model. In the 5 groups of individuals with the highest exposure, mixtures are formed by pairs of pesticides with correlations above 0.7. Seven mixtures of 2-6 pesticides each were characterised. We identified the commodities that contributed the most to exposure. Pesticide mixtures can either be components of a single plant protection product applied together on the same crop or be from separate products that are consumed together during a meal. Of the 25 pesticides forming the mixtures, two--DDT and Dieldrin--are known persistent organic pollutants. The approach developed is generic and can be applied to all types of substances found in the diet in order to characterise the mixtures that should be studied first because of their adverse effects on health.

Relevance of integrating agricultural practices in pesticide dietary intake indicator.

The aim of this study is to develop a new indicator of pesticide dietary intake to screen pesticides to include in monitoring programs. This new indicator called the adjusted TMDI (TMDI_Ad), taking account actual pesticide agricultural uses in France, is more precise than the theoretical maximum dietary intake (TMDI), based on maximum residue levels (MRLs) that is usually used. This new modeling of dietary intake is refined according to actual agricultural pesticide uses on 44 raw agricultural commodities (RAC), among the most consumed in France, and the rate of food importation of these RAC. The TMDI_Ad was below the TMDI for 322 pesticides (79%). The TMDI was above the ADI, for 46 substances. Although 43 of them had a TMDI_Ad below the TMDI, still 36 had a TMDI_Ad above the ADI, which corresponded to substances with the lowest ADIs. Overall, these results indicate that the TMDI_Ad is a useful tool to plan monitoring programs and to refine dietary exposure, according to actual pesticide uses. However, for very toxic substances, having a very low ADI, such as unauthorized substances, other studies have to be conducted in order to better estimate consumer dietary intakes.

Quantitative Risk Assessment Relating to the Inadvertent Presence of Peanut Allergens in Various Food Products

Since 2005, European food regulations require major allergens, including peanut, to be declared on the label where the allergen is intentionally present in the food. However, even if not mentioned in the list of ingredients, peanut allergen may be inadvertently present in a large range of packaged food and consequently may affect many peanut allergic individuals. This work is an exercise in quantifying the allergic risk for peanut allergic individuals in France when exposed to food products that may contain low level of peanuts due to cross-contamination. This quantification is based on a probabilistic approach published by Rimbaud et al. in 2010 (Rimbaud et al. 2010). Food products analysed for the possible presence of peanut traces in scientific literature were selected. For each foodstuff, the allergic risk associated with their consumption was estimated using the French individual food consumption survey, representative of the general French population. An internet survey on the attitudes of peanut-allergic individuals toward food precautionary labelling was conducted. For three foodstuffs, the allergic risk was then refined integrating the information on specific food behaviours of French allergic individuals. Considering the mean probability, inadvertent presence of peanuts was identified in 20% to 37% of products. Adults were exposed to up to 12.5 mg of peanut protein on 97.5% of their eating occasions. The mean risk of reaction ranged from 0.2% to 2.4%. Considering eating occasions for all the products, 1.5% of the peanut-allergic adults would have at least one allergic reaction in a week. In undertaking this modelling exercise, we have demonstrated the benefits of integrating all available information to underpin decision making in the area of food allergen cross-contamination. We have also highlighted the need to generate more data to further refine the risk assessment for the benefit of allergic consumers.

Dietary exposure of 18-month-old Guadeloupian toddlers to chlordecone

Chlordecone is an organochlorine insecticide used in the French West Indies until 1993. Toddlers are expected to be differently exposed than older children and adults. The dietary exposure to chlordecone of 18-month-old Guadeloupian toddlers was assessed through different scenarios depending on whether the subjects live on a soil-contaminated place or not and on their supply habits. Food contamination data came from the RESO study performed in 2005-2006. Consumption data derived from a dietary survey conducted in 2005-2008. Results were compared to those of other age groups. Chronic dietary exposures to chlordecone were estimated in a range of 0.018-0.051 μg/kg bw/day (P95: 0.044-0.096) for toddlers living in a non contaminated area and between 0.045-0.078 μg/kg bw/day (P95: 0.110-0.144) for toddlers living in a contaminated area. The probability of exceeding the chronic health-based value of 0.5 μg/kg bw/day was null. These results suggest that 18-month-old toddlers are less exposed than groups aged over 3 years old. This can be explained by their consumption pattern mostly based on milk and fruits, which are not highly contaminated by chlordecone. The acute health-based value of 10 μg/kg bw/day could be exceeded when consuming of highly contaminated taros, showing the importance of regulatory maximum limit.