Thierry Guérin

Dietary exposure estimates of 18 elements from the 1st French Total Diet Study.

To estimate the dietary exposure of the main minerals and trace elements from retail food typically consumed by the French population, samples were purchased and then prepared and cooked prior to analysis. A total of 1080 individual food composites samples were collected and analysed for 18 elements (arsenic, lead, cadmium, aluminium, mercury, antimony, chrome, calcium, manganese, magnesium, nickel, copper, zinc, lithium, sodium, molybdenum, cobalt and selenium). Intakes were calculated from different food consumption patterns found in France for average and high consumers among adults and children. Dietary exposures of those consumers estimated from the France 2000 Total Diet Study (FTDS) are reported, and compared with existing nutritional reference values (Lowest threshold Intake, LTI) or toxicological reference values (Provisional Tolerable Weekly Intake, PTWI or Upper Level, UL) of the respective element and from previous French studies. This study confirms for the populations concerned, the low probability of nutritional or health risks due to food consumption.

Dietary exposure to trace elements and health risk assessment in the 2nd French Total Diet Study.

Dietary exposure of the French population to trace elements has been assessed in the second national Total Diet Study (TDS). Food samples (n = 1319) were collected between 2007 and 2009 to be representative of the whole diet of the population, prepared as consumed, and analyzed. Occurrence data were combined with national individual consumption data to estimate dietary exposure for adults and children mean and high consumers. Compared to the 1st French TDS performed in 2000-2004, exposure is higher for cadmium, aluminium, antimony, nickel, cobalt and lower for lead, mercury and arsenic. For aluminium, methylmercury, cadmium, lead and inorganic arsenic risk cannot be ruled out for certain consumer groups. It still appears necessary to continue undertaking efforts to reduce exposure to these elements. Due to the lack of robust toxicological data and/or speciation analysis in food on chromium, tin, silver and vanadium to perform a risk assessment, data on occurrence and dietary exposure are provided as Supplementary material. In order to minimize nutritional and chemical risks, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) reiterates its recommendation for a diversified diet (food items and origins).

Determination of 20 trace elements in fish and other seafood from the French market.

The levels of 20 essential or toxic trace elements in 159 fish, other seafood and seafood products on the French coastal market collected between January and April 2005 were measured by ICP-MS. The concentration ranges (mg/kg of fresh mass) for the elements determined were compared with previous studies. The contents of Co, Cu, Fe, Li, Mn, Se, Zn and Pb found in fish are close to or often lower than previous studies. For other seafood, comparison is difficult due to the lack of data on a more global scale. However, it should be noted that the contents of Ag were found considerably higher in this study.

Dietary exposure and biomarkers of arsenic in consumers of fish and shellfish from France

Seafood, especially fish, is considered as a major dietary source of arsenic (As). Seafood consumption is recommended for nutritional properties but contaminant exposure should be considered. The objectives were to assess As intake of frequent French seafood consumers and exposure via biomarkers. Consumptions of 996 high consumers (18 and over) of 4 coastal areas were assessed using a validated food frequency questionnaire. Seafood samples were collected according to a total diet study (TDS) sampling method and analyzed for total As, arsenite (AsIII), arsenate (AsV), arsenobetaïne (AsB), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). The average As dietary exposure is 94.7+/-67.5 microg/kg bw/week in females and 77.3+/-54.6 microg/kg bw/week in males (p<0.001) and the inorganic As dietary exposure is respectively 3.34+/-2.06 microg/kg bw/week and 3.04+/-1.86 microg/kg bw/week (p<0.05). Urine samples were collected from 382 of the subjects. The average urinary As concentration is 94.8+/-250 microg/g creatinine for females and 59.7+/-81.8 microg/g for males (p<0.001). Samples having an As concentration above 75 microg/g creatinine (n=101) were analyzed for inorganic As (As(III), As(V), MMA(V) and DMA(V)) which was 24.6+/-27.9 microg/g creatinine for males and 27.1+/-20.6 microg/g for females. Analyses do not show any correlation between dietary exposure and urinary As. These results show that biological results should be interpreted cautiously. Diet recording seems to be the best way to assess dietary As exposure. Seafood is a high source of As exposure but even among high consumers it is not the main source of toxic As. From a public health point of view these results should be interpreted carefully in the absence of international consensus on the health-based guidance value.

Determination of seven arsenic species in seafood by ion exchange chromatography coupled to inductively coupled plasma-mass spectrometry following microwave assisted extraction: Method validation and occurrence data

The determination of seven arsenic species in seafood was performed using ion exchange chromatography on an IonPac AS7 column with inductively coupled plasma mass spectrometry detection after microwave assisted extraction. The effect of five parameters on arsenic extraction recoveries was evaluated in certified reference materials. The recoveries of total arsenic and of arsenic species with the two best extraction media (100% H(2)O and 80% aqueous MeOH) were generally similar in the five seafood certified reference materials considered. However, because MeOH co-elutes with arsenite, which would result in a positively biased arsenite concentration, the 100% H(2)O extraction conditions were selected for validation of the method. Figures of merit (linearity, LOQs (0.019-0.075 mg As kg(-1)), specificity, trueness (with recoveries between 82% (As(III)) and 104% (As(V) based on spikes or certified concentrations), repeatability (3-14%), and intermediate precision reproducibility (9-16%) of the proposed method were satisfactory for the determination of arsenite, monomethylarsonic acid, dimethylarsinic acid, arsenate, arsenobetaine and arsenocholine in fish and shellfish. The performance criteria for trimethylarsine oxide, however, were less satisfactory. The method was then applied to 65 different seafood samples. Arsenobetaine was the main species in all samples. The percentage of inorganic arsenic varied between 0.4-15.8% in shellfish and 0.5-1.9% at the utmost in fish. The main advantage of this method that uses only H(2)O as an extractant and nitric acid as gradient eluent is its great compatibility with the long-term stability of both IEC separation and ICP-MS detection.

Multielemental speciation of As, Se, Sb and Te by HPLC-ICP-MS

An anion exchange HPLC-ICP-MS procedure allowing the simultaneous multielemental speciation analysis of arsenic, selenium, antimony and tellurium has been developed. Four arsenic species (As(III), As(V), monomethylarsonic acid and dimethylarsinic acid), two selenium species (Se(IV) and Se(VI)) may be determined in a single run as well as one antimony (Sb(V)) and one tellurium species (Te(VI)). Alternatively Sb and/or Te may be used as internal standards for As and Se speciation studies. Optimisation of ICP-MS conditions led to satisfactory relative (0.01 (Sb(V)) to 1.8 (Se(VI)) ng ml(-1)) and absolute detection limits (1-180 pg). Reproducibility ranged from 3.1 to 5.6% and the linearity was verified in the 0-200 ng ml(-1) range.

Estimation of the dietary intake of pesticide residues, lead, cadmium, arsenic and radionuclides in France.

Estimation of the dietary exposure of French consumers to 10 pesticides (omethoate, oxydemeton, phosalon, phosphamidon, triazophos, dicofol (op′+pp′), parathion ethyl, dichlorvos, procymidon and vinchlozolin), three heavy metals (lead, cadmium and arsenic) and three radionuclides (134caesium, 137caesium and 131iodine) from collected duplicate portion in mass catering establishments in 1998/1999 are reported, and compared with those from previous French studies as well as those from other countries. Dietary exposure estimates appear to be reassuring, in that Estimated Daily Intake (EDI) estimates are generally low, representing at maximum only 4% of the Acceptable Daily Intake (ADI) for pesticide residues and 28% of the Provisional Tolerable Weekly Intake (PTWI) for heavy metals. Moreover, none of the three radionuclides has been found in duplicate meals. When comparisons are possible, estimated dietary exposures for heavy metals are lower than those from previous French studies and similar or above those from other countries.

Methylmercury exposure assessment using dietary and biomarker data among frequent seafood consumers in France CALIPSO study.

BACKGROUND Seafood is considered by toxicologists as the main source of methylmercury (MeHg), but little data is available concerning contamination of seafood and MeHg status of French frequent consumers. OBJECTIVES The objectives were to assess food exposure and biomarker of exposure of MeHg from a group of frequent consumers of seafood. METHODS Two approaches to exposure assessment were used: the currently used food intake and the biomarker of exposure. A validated food frequency questionnaire (FFQ) was used to assess seafood consumptions for 80 products of 385 frequent consumers aged 18 and over in four French coastal areas. Seafood samples were collected in each region considering preservation methods and supply habits according to a total diet study sampling. Food samples were analyzed for MeHg. Exposure was assessed by combining consumptions with contamination data. Whole blood samples were collected from the volunteers and analyzed for MeHg. RESULTS The mean dietary exposure to MeHg or weekly intake (WI FFQ) was 1.51+/-1.17 microg/kg bw/wk. Thirty-five percent of the subjects exceed the Joint Expert Committee on Food Additives (JECFA) provisional tolerable weekly intake (PTWI), whereas the use of the biological results with the JECFA/Environmental Protection Agency (EPA) one-compartment pharmacokinetic model to calculate weekly intake (WI PKM) shows that only 2% of subjects exceed the PTWI. The mean of the individual ratios WI FFQ/WI PKM is 4.3 and the higher the WI FFQ and the blood MeHg level, the lower is the ratio, close to 1-2. CONCLUSIONS These analyses support the assumption that the calculated dose of methylmercury is overestimated with the FFQ-based method used in this study. Since FFQ are commonly used in risk assessments, the overestimate of dose is public health protective and this finding is somewhat reassuring from a public health point of view, especially since the JECFA or EPA have applied uncertainty factors of 3.2 or 3, respectively, to take into account the inter-individual pharmacokinetic variability.

Distribution and relationships of As, Cd, Pb and Hg in freshwater fish from five French fishing areas

The concentrations of arsenic, cadmium, mercury and lead in 149 muscle samples of eight freshwater fish species (European eel, bream, common carp, European catfish, roach, perch, pike and pikeperch) from five different French fishing areas from contaminated and control sites were measured by inductively coupled plasma mass spectrometry after microwave digestion under pressure. No significant correlation was found between the condition factor (CF), based on the length-mass relationship, and As, Cd and Pb levels in all the samples analysed, but a positive correlation was detected between CF and Hg levels (P<0.0001, R=0.49). Positive correlations with body length were only found for Hg in roach (P<0.05, R=0.32) and Pb in bream (P<0.05, R=0.48) and correlations with both body weight and length were also found for Hg in pike (P<0.05, R=0.90 and 0.86) and Cd in European eel (P<0.01, R=-0.35 and -0.37). The average content and the standard deviation in fish muscle samples was 0.007±0.012, 0.102±0.077, 0.142±0.097 and 0.035±0.053 mg kg(-1) of wet mass for Cd, As, Hg and Pb, respectively. Significant differences were established between groups of predatory fish and non-predatory fish for Hg and Pb, and between control and contaminated sites in the whole selection and also within feeding guilds, i.e. the values of Hg in the benthophagic fish were significantly different between these sites. Finally, these results were also compared for each species with previous French and European studies.

Optimisation and critical evaluation of a collision cell technology ICP-MS system for the determination of arsenic in foodstuffs of animal origin.

The determination of arsenic (75As) was studied using an ICP-MS equipped with collision cell technology (CCT). Different mixtures of gases (He and H2) were tested using HCl conditions and a He flow rate of 4 mL min(-1) was found to be suitable for the removal of the poly-atomic spectral interference [40Ar35Cl]+. Trueness of the optimised method has been evaluated in both standard and CCT modes on six certified reference materials in foodstuffs of animal origin and on three external proficiency testing schemes (FAPAS). The results obtained generally coincided with the certified values, except for CCT mode in some categories of samples (meat, mussels and milk powder), for which a positive bias on results was observed due to the formation of poly-atomic interferences within the collision cell. The main interferences were studied and their contributions estimated. [58Fe16O1H]+ and [74Ge1H]+ were the most significant interferences formed in the cell. Finally, different parameters (e.g. hexapole and quadrupole bias voltage, nebuliser gas flow) were optimised to try to attenuate these interferences.