Estimation of blood lead levels in the French population using two complementary approaches: Esteban (2014-2016) as part of the human biomonitoring program and the national surveillance system for childhood lead poisoning (2015-2018).

BACKGROUND: Used widely for centuries, lead is a common environmental pollutant. As a cumulative toxic, its presence in the body is always evidence of exposure, and health effects occur without threshold. Though regulated by European directives, lead requires close monitoring due to its environmental persistence and toxicity. METHODS: The first data source was the French surveillance system for monitoring childhood lead poisoning, which records the screening results of children (-18 years), providing data on their temporal and geographical distribution, characteristics, and risk factors. The second data source was Esteban, a cross-sectional study conducted in 2014-2016 on a random sample of the French population as part of the human biomonitoring program. The Esteban lead study concerns 904 children (6-17 years) and 999 adults (18-74 years), providing data on biological samples, sociodemographic characteristics, occupational exposure, environmental and dietary factors. RESULTS: The surveillance system highlighted that lead poisoning affected 10% of children screened between 2015 and 2018. The main risk factor remains housing. Esteban confirmed this observation, finding a general mean of blood lead level (BLL) at 9.9 and 18.5 µg/L for children and adults, respectively. In children, parents' occupation increased BLLs. In adults, the greatest exposure factors were smoking, age, place of residence, alcohol, bread-based products, and homegrown livestock products. In both, drinking tap water and year of housing construction increased BLLs. CONCLUSIONS: The surveillance system showed a high number of children with lead poisoning despite the implementation of prevention measures, which mainly concern lead paints in old and degraded homes. To help identify children at risk, healthcare providers need to know about exposure from housing and the emerging sources identified in the Esteban survey. Despite lower BLLs, the well-known risk factors of lead exposure persist, meaning prevention efforts must continue in order to limit their impact on the population.

Relationships between molds and asthma suggesting non-allergic mechanisms. A rural-urban comparison.

BACKGROUND: A fungal index, based on specific microbial volatile organic compounds (MVOCs) emission, was employed and related to asthma in children from rural and urban dwellings after stratification on the children atopic status. METHODS: A nested case-control design was used to draw, from 2 cross-sectional surveys, 20 asthmatics and 26 controls living in urban areas, and 24 asthmatics and 25 controls in rural areas. MVOCs levels were assessed in the living-room during one week; during that week, children performed clinical tests and their parents were invited to fill in a questionnaire on respiratory health. RESULTS: According to the objective fungal index, 70.5% of cases and 49.0% of controls were exposed to molds. More children with current asthma had experienced mold exposure in their homes (OR=3.38, 95% CI (1.16; 9.90)), especially amongst children living in rural areas. Atopic status modified this association: exposure to molds was found to be related to current asthma only in non-atopic children (OR=10.42, 95% CI (2.42; 44.81)). Among urban -dwelling children that could be screened at hospital, asthmatic children living in contaminated dwellings had a higher proportion of blood neutrophils and a lower FEV1 (forced expiratory volume in 1 second) than non-exposed ones. CONCLUSION: Our findings based on an objective assessment of MVOCs suggest adverse respiratory effects of molds. Our results suggest that when looking at the aetiology of non-atopic asthma, mold exposure should be systematically assessed.

Poor air quality in classrooms related to asthma and rhinitis in primary schoolchildren of the French 6 Cities Study.

BACKGROUND: Relationships between indoor air quality (IAQ) found in schools and the allergic and respiratory health of schoolchildren have been insufficiently explored. A survey was conducted in a large sample of classrooms of primary schools in France to provide objective assessments of IAQ to which young schoolchildren are exposed in classrooms, and to relate exposure to major air pollutants found in classrooms to asthma and allergies of schoolchildren. METHODS: Concentrations of fine particles with aerodynamic diameter ≤2.5 µm (PM(2.5)), nitrogen dioxide (NO(2)) and three aldehydes were objectively assessed in 401 randomly chosen classrooms in 108 primary schools attended by 6590 children (mean age 10.4 years, SD ±0.7) in the French 6 Cities Study. The survey incorporated a medical visit including skin prick testing (SPT) for common allergens, a test for screening exercise-induced asthma (EIA) and a standardised health questionnaire completed by parents. RESULTS: Children were differently exposed to poor air quality in classrooms, with almost 30% being highly exposed according to available standards. After adjusting for confounders, past year rhinoconjunctivitis was significantly associated with high levels of formaldehyde in classrooms (OR 1.19; 95% CI 1.04 to 1.36). Additionally, an increased prevalence of past year asthma was found in the classrooms with high levels of PM(2.5) (OR 1.21; 95% CI 1.05 to 1.39), acrolein (OR 1.22; 95% CI 1.09 to 1.38) and NO(2) (OR 1.16; 95% CI 0.95 to 1.41) compared with others. The relationship was observed mostly for allergic asthma as defined using SPT. A significant positive correlation was found between EIA and the levels of PM(2.5) and acrolein in the same week. CONCLUSIONS: In this random sample, air quality in classrooms was poor, varied significantly among schools and cities, and was related to an increased prevalence of clinical manifestations of asthma and rhinitis in schoolchildren. Children with a background of allergies seemed at increased risk.

Respiratory health and indoor air pollutants based on quantitative exposure assessments.

We reviewed the main epidemiological studies that evaluate the respiratory effects of indoor air pollutants quantitatively in industrialised countries. Consistent results support short-term (aggravation) and, although more rarely, long-term (prevalence augmentation) effects on asthma, chronic bronchitis and chronic obstructive pulmonary disease (COPD) in indoor settings with poor air quality. Environmental tobacco smoke is one of the most important risks for respiratory symptoms and diseases worldwide. The evidence is also reliable for indoor nitrogen dioxide and particulate matter, which have been associated with asthma, bronchitis and COPD. Whereas formaldehyde and volatile organic compounds seem to be the main pollutants in indoor settings, relevant papers on their respiratory effects are still scarce, and limited to asthma and bronchitis. Moulds have been associated with an increased risk of asthma and COPD. Contradictory results have been found between endotoxins and asthma. The role of phthalates, persistent organic pollutants and flame retardants in respiratory diseases remains to be established. Results from rural areas of industrialised countries indicate that exposure to some indoor bio-contaminants might be protective in early life, while it is associated with adverse respiratory adverse effects in adulthood. Studies focusing on indoor air pollutants should be developed to better understand their involvement in the inception and aggravation of respiratory diseases.

Prosulfocarb at center stage!

Prosulfocarb is a thiocarbamate herbicide that is rapidly growing in use due to the progressive bioresistance of weeds to certain pesticides and the ban and/or limitation of others. However, the use of prosulfocarb is only recent, and the relevant literature is scarce. The environmental and food impact of prosulfocarb has already been observed, and its transfer mode from targeted crops to untargeted parcels has been investigated. This expertise highlights the volatilization effect to explain the pollution of lone parcels and hedge inefficiency against residue spreads.

Identification of pesticides exposure biomarkers for residents living close to vineyards in France.

Biomonitoring can be relevant for assessing pesticides exposure of residents living close to vineyards (LCTV). However, because xenobiotics are generally present at low levels in human biological matrices and the sources of pesticide exposure are multiple, several challenges need to be overcome to reliably assess exposure in residents LCTV. This includes particularly identifying the most appropriate exposure biomarkers, the biological matrices in which they should be measured, and analytical methods that are sufficiently sensitive and specific to quantify them. The aim of the present study was to develop a tiered approach to identify relevant biomarkers and matrices for assessing pesticide exposure in residents LCTV. We used samples from a biobank for 121 adults and children included in a national prevalence study conducted between 2014 and 2016 who lived near or far from vineyards. We analyzed five priority pesticides (folpet, mancozeb, tebuconazole, glyphosate, and copper) and their metabolites in urine and hair samples. We identified relevant biomarkers according to three criteria related to: i) the detection frequency of those pesticides and metabolites in urine and hair, ii) the difference in concentrations depending on residence proximity to vineyards and, iii) the influence of other environmental and occupational exposure sources on pesticide levels. This tiered approach helped us to identify three relevant metabolites (two metabolites of folpet and one of tebuconazole) that were quantified in urine, tended to be higher in residents LCTV than in controls, and were not significantly influenced by occupational, dietary, or household sources of pesticide exposure. Our approach also helped us to identify the most appropriate measurement strategies (biological matrices, analytical methods) to assess pesticide exposure in residents LCTV. The approach developed here was a prerequisite step for guiding a large-scale epidemiological study aimed at comprehensively measuring pesticides exposures in French residents LCTV with a view to developing appropriate prevention strategies.

Infant total diet study in France: Exposure to substances migrating from food contact materials.

A total diet study (TDS) was conducted in France to assess the health risks related to the chemicals in food of non-breastfed children under three years of age (Infant TDS). For the first time, substances coming from food contact materials, such as bisphenol A (BPA), bisphenol A diglycidyl ether (BADGE) and its derivatives, some phthalates, and some ink photoinitiators, were targeted because of growing interest in these substances. Food samples were collected to be representative of the whole diet of non-breastfed children aged 1-36 months, and prepared as consumed prior to analysis. Dietary exposure was assessed for 705 representative children under three years of age. Generally, the substances from food contact materials were detected in few samples: 38% for BPA, 0% for BADGE and its derivatives, 0-35% for phthalates, 1.9% for benzophenone, and 0% for the other ink photoinitiators. Regarding exposure levels, the situation was deemed tolerable for BADGE and its hydrolysis products, di-isodecyl phthalate, dibutyl phthalate, butyl benzyl phthalate, bis(2-ethylhexyl) phthalate, and di-isononyl phthalate, benzophenone, and 4-methylbenzophenone. Only for BPA, the exposure levels of some children exceeded the lowest toxicological value established by the French Agency for Food, Environmental and Occupational Health & Safety at 0.083 µg.kg bw-1.d-1. The temporary tolerable daily intake of the European Food Safety Authority (EFSA), set at 4 µg.kg bw-1.d-1, was never exceeded. However, actual exposure to BPA was probably overestimated, as well as the associated risk, because the foods were sampled prior to the recent regulations banning BPA in food packaging. This study is the first worldwide to provide an estimate of infant food contamination levels and exposures of children under 3 years of age, based on a TDS approach. It therefore provides key data on the exposure of this particularly sensitive population to substances released from food contact materials, and presents useful data for studies evaluating exposure to mixtures or aggregated exposure.

Monitoring of pesticides in ambient air: Prioritization of substances.

Despite the richness of data collected on pesticide concentrations in ambient air in France, knowledge on this topic remains partial and heterogeneous in the absence of specific regulations. The population exposure remains thus difficult to estimate; therefore it was necessary to define modalities for implementing national monitoring of pesticides in ambient air in metropolitan France and in the overseas territories. The objective of this work was to identify which active substances (a.s.) have to be monitored in priority. As part of a collective expertise, a group of multidisciplinary experts has developed a method to rank active substances authorised as plant protection products, biocides and antiparasitic agents, which were available on the French market in 2015. A 3-steps approach has been developed. The first step consisted of a theoretical approach based on a hierarchy of substances according to four criteria: (a) national uses, (b) emission potential to the air, (c) persistence in the air, and (d) chronic toxicity. The three first criteria give information on their potential to be present in the atmosphere, and the fourth criterion allows to consider their potential of hazard. The second step was an observational approach based on existing database on pesticide air measurements in France. In the third step, both approaches were combined using decision trees to select priority pesticides. Among the 1316 a.s. first identified from the EU Pesticides database, 90 were selected, among which 43 required metrological and/or analytical development. The experts recommended confirming the relevance of performing a longer term monitoring of these a. s. after a one-year exploratory campaign. The proposed method is reproduceable, transparent, easy to update (e.g. in the light of a change in product authorization), and can be adapted to other agricultural and geographical conditions, and objectives (e.g. monitoring of the ecotoxicological effects of pesticides).

Air pollution and increased levels of fractional exhaled nitric oxide in children with no history of airway damage.

Air pollution is associated with a wide range of adverse respiratory events. In order to study the mechanism associated with these effects, the relationships between fractional exhaled nitric oxide (FeNO), a potential marker of airway inflammation, and exposure to air pollution were examined in schoolchildren. FeNO was measured in 104 children (34 asthmatics and 70 non-asthmatics) drawn from the general population simultaneously with air pollution assessments (fine particles with an aerodiameter under 2.5 microm, nitrogen dioxide, acetaldehyde, and formaldehyde, with pumps and passive samplers) in schoolyards and classrooms. Asthmatics exhaled more FeNO than non-asthmatics. FeNO levels were significantly elevated in both asthmatic and non-asthmatic children exposed to high concentrations of formaldehyde, acetaldehyde, and PM(2.5). Differences between high versus low exposure in non-asthmatics resulted in an FeNO increase ranging from 45% for indoor acetaldehyde to 62% for indoor PM(2.5). Stronger associations were found in non-asthmatic children who were atopic, suggesting that atopic children may be more sensitive to air pollution than non-atopic children. Exposure to air pollution may lead to airway inflammation, as measured by FeNO, in schoolchildren. These associations occur even in children with no history of airway damage and seem to be enhanced in atopic subjects.

Health risk assessment to dioxins, furans and PCBs in young children: The first French evaluation.

A total diet study (TDS) was conducted between 2010 and 2016 to characterize the health risk related to chemical residues in food of French not breastfed children under three years of age (infant TDS). Among the targeted substances, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) have been characterized as they accumulate through the food chain, especially in lipid-rich food items, and because they have been associated with a number of adverse effects in humans. Food samples (n = 180) were collected to be representative of the dioxins and PCB exposure through the whole diet of non-breastfed children from 1 to 36 months old and prepared as consumed (including cooking) prior to analysis. Dietary exposure was then assessed for 705 representative children under 3 years of age based on their food consumptions recorded through a 3-consecutive-days record. Levels of PCDD/Fs and PCBs in infant food were lower than those observed in common food, leading to significant differences in exposure according to age groups. Mean exposures to PCDD/Fs ranged from 0.22 to 0.44 pg TEQWHO05.kg bw-1.d-1 (0.40-0.65 at the 90th percentile), depending on the age group and the hypothesis considered to manage left-censored data. Mean exposure to non-dioxin-like PCBs ranged from 0.87 ng kg bw-1.d-1 (1.55 at the 90th percentile) in the 1-4 months old children to 3.53 ng kg bw-1.d-1 (5.44 at the 90th percentile) in the 13-36 months old children. For dioxins and NDL-PCBs, the tolerable daily intake (TDI) was exceeded for some age groups, in particular for older ones. Therefore, appropriate management measures must continue for reducing exposure; it concerns mainly common milk in youngest children, ultra-fresh dairy products and fish. For PCBs, recommendations on fish consumption should be reminded. Moreover, toxicity studies focusing on mixtures of dioxin-like compounds should be encouraged in order to take into account effect of mixtures.

Dietary exposure to mycotoxins in the French infant total diet study.

The present study evaluated the exposure of children aged from one to 36 months to seven groups of mycotoxins, in the context of the infant French Total Diet Study (iTDS). Exposure was then compared to the health-based guidance values (HBGVs) for each mycotoxin. The value of the 90th percentile of exposure to nivalenol, patulin, fumonisins and zearalenone was less than 40% of the HBGV considered relevant for children. On the other hand, a risk could not be excluded for ochratoxin A and aflatoxins as exposure was close to the HBGV for ochratoxin A and the margin of exposure was much lower than the critical margin of 10,000 for aflatoxins. The HBGVs for toxins T2 and HT2, and for deoxynivalenol (DON) and its acetylated compounds were exceeded. Five percent to 10% of the children aged 5-12 months exceeded the HBGV considering the lower bound hypothesis for toxins T2 and HT2 and 7.5%-27% of the children aged 5 months and above exceeded the HBGV for DON. Consequently, the exposure of young children raises safety concerns for T2/HT2 and DON. Efforts should therefore be pursued to decrease their exposure to these molecules.

Dietary exposure to pesticide residues and associated health risks in infants and young children - Results of the French infant total diet study.

A total diet study (TDS) was undertaken to estimate the chronic dietary exposure to pesticide residues and health risks for the French infants and young children below 3 years old. As a whole, 516 pesticides and metabolites were analysed in 309 food composite samples including 219 manufactured baby foods and 90 common foods, which cover 97% of infants and young children's diet. These composite samples were prepared using 5,484 food products purchased during all seasons from 2011 to 2012 and processed as consumed. Pesticide residues were detected in 67% of the samples and quantified in 27% of the baby food samples and in 60% of the common foods. Seventy-eight different pesticides were detected and 37 of these quantified at levels ranging from 0.02 to 594 µg/kg. The most frequently detected pesticides (greater than 5% samples) were (1) the fungicides 2-phenylphenol, azoxystrobin, boscalid, captan and its metabolite tetrahydrophthalimide, carbendazim, cyprodinil, difenoconazole, dodine, imazalil, metalaxyl, tebuconazole, thiabendazole, (2) the insecticides acetamiprid, pirimiphos-methyl and thiacloprid, (3) the herbicide metribuzin and (4) the synergist piperonyl butoxide. Dietary intakes were estimated for each of the 705 individuals studied and for 431 pesticides incl. 281 with a toxicological reference value (TRV). In the lower-bound scenario, which tends to underestimate the exposure, the TRV were never exceeded. In the upper-bound scenario that overestimates exposure, the estimated intakes exceeded the TRV for dieldrin and lindane (two persistent organic pollutants) and propylene thiourea, a metabolite of propineb. For these three substances, more sensitive analyses are needed to refine the assessment. For 17 other detected and/or prioritised pesticides, the risk could not be characterised due to the lack of a valid TRV, of certain food analyses or the absence of analytical standards for their metabolites.

Dietary exposure to perfluoroalkyl acids, brominated flame retardants and health risk assessment in the French infant total diet study.

Perfluoroalkyl acids (PFAAs) and brominated flame retardants (BFRs) are widely used and present in human food. Due to the increased susceptibility to pollutants of the young children, we conducted a total diet study focusing on this population. Around 200 baby and common food composite samples, prepared "as consumed", have been analysed for PFAAS, hexabromocyclododecanes, polybrominated biphenyls, polybrominated diphenyl ethers and tetrabromobisphenol A. The dietary exposure of 705 children aged 1-36 months was assessed. PFAAS were detected only in one fish sample. Detection rates varied from 4 to 93% for BFRs, depending on the congeners. Regarding the provisional health-based guidance values set by EFSA in 2018 for PFOA and PFOS at 0.8 and 1.8 ng kg bw-1.d-1, respectively, 20-100% of children exceeded them, depending on the age. Efforts should be made to decrease the PFAAs contamination of common foods. This study also highlighted that for other PFAAs, toxicological studies are needed to set dietary health-based guidance values, to assess their related health risk. Conversely, dietary exposures to BRFs were much lower than the respective health based guidance values or margins of safety were high enough, and consequently not considered at-risk due to very low contamination of the infant specific foods.

French infant total diet study: Dietary exposure to heat-induced compounds (acrylamide, furan and polycyclic aromatic hydrocarbons) and associated health risks.

A total diet study (TDS) was conducted between 2010 and 2016 to assess the risk associated with chemicals in food of non-breast-fed children from 1 to 36 months living in France. Food samples were collected, prepared "as consumed", and analyzed for chemicals of public health interest. Acrylamide, furan and polycyclic aromatic hydrocarbons (PAHs) were analyzed as heat-induced compounds produced mainly during thermal processing of foods. Dietary exposure was assessed for 705 representative children using food consumptions recorded through a 3-consecutive-days record. As all calculated margins of exposure (MOE) for PAHs exceeded 10 000, dietary exposure of the infant and toddler population was deemed tolerable with regard to the carcinogenic risk. Conversely, the exposure levels to acrylamide and furan were considered as of concern, requiring management measures to reduce the exposure essentially by reducing the formation of heat-induced compounds during food production or preparation processes. Efforts should mainly focus on major contributors to the exposure, i.e. sweet and savoury biscuits and bars, and potatoes and potato products for acrylamide, baby jars of vegetables, with or without meat or fish for acrylamide and furan.

Mercury in foods from the first French total diet study on infants and toddlers.

A very sensitive method using a direct mercury analyser was developed and validated according to the accuracy profile procedure to determine mercury levels in foods mainly consumed by infants and toddlers. Total mercury was not detected (LOD of 0.30µg.kg-1 fresh weight) in 92.4% of the 291 food samples analysed or at relatively low concentrations, lesser than or equal to LB/UB 0.5/1.0µg.kg-1 in all samples, except in fish samples (mean LB/UB 25µg.kg-1 with a maximum of 53µg.kg-1). Levels of total mercury in these foods were in all cases within permitted Regulatory limits of 500 or 1000µg.kg-1 in fishery products and muscle meat of fish.

Levels of acrylamide in foods included in 'the first French total diet study on infants and toddlers'.

This study describes an optimisation and validation process using liquid chromatography coupled with tandem mass spectrometry to quantify acrylamide in foods mainly consumed by infants and toddlers. A limit of quantification of 5µg.kg-1 for both solid and liquid samples was achieved, except for unprepared infant cereals (LOQ of 18µg.kg-1). The method was then applied to 141 food samples from the first French total diet study on infants and toddlers. Acrylamide was detected in most samples at mean LB/UB concentrations ranging from 0.14 to 102µg.kg-1. The "Follow-on formula" and "Infant formula" products contained the lowest average content (LB/UB of 0.14/2.2µg.kg-1 and 0.60/2.9µg.kg-1 respectively) and the "Sweet and savoury biscuits and bars" (102µg.kg-1; n=1 represented by a plain dry biscuit) contained the highest.

Levels of furan in foods from the first French Total Diet Study on infants and toddlers.

This study describes an optimisation and validation process on a method using gas chromatography coupled with mass spectrometry to quantify furan in foods consumed mainly by infants and toddlers. The method that we developed allowed for low limits of quantification for liquid (1 µg kg-1) and solid (2 µg kg-1) samples. Our method was then applied to 134 food samples from the first French Total Diet Study on infants and toddlers. Furan was detected in 84% and quantified in 61% of the samples, at average lower and upper bound (LB/UB) concentrations ranging from 0 to 44 µg kg-1. The sugar and sugar derivatives, milk, growth milk, infant formulae and "other hot beverages categories contained the lowest average content (LB/UB ≤ 1 µg kg-1) and breakfast cereals contained the highest (LB/UB = 44 µg kg-1).

French infant total diet study: Exposure to selected trace elements and associated health risks.

A total diet study (TDS) was conducted between 2010 and 2016 to assess the risk associated with chemicals in food of non-breast-fed children under three living in France. 291 composite food samples were prepared "as consumed" and analyzed for 16 trace elements: aluminium (Al), antimony (Sb), arsenic (As), barium (Ba), cobalt (Co), chromium (Cr), gallium (Ga), germanium (Ge), lead (Pb), mercury (Hg), nickel (Ni), silver (Ag), strontium (Sr), tellurium (Te), tin (Sn), vanadium (V). Dietary exposure was assessed for 705 representative children using food consumptions recorded through a 3-consecutive-days record. For inorganic mercury, chromium III, and antimony, the exposure levels were lower than the health-based guidance values and the risk was considered tolerable. Conversely, the exposure levels to inorganic arsenic, lead and nickel were higher than the health-based guidance values for a part of children and were considered as a concern, requiring management measures to reduce the exposure. For aluminium, methylmercury, strontium, chromium VI, cobalt, and barium, a risk could not be ruled out because of uncertainty sources. As a precautionary measure, reducing the exposure is recommended. For chemicals without robust health-based guidance value (organic arsenic, gallium, germanium, silver, tin, tellurium and vanadium), additional data are needed for risk assessment.

Dietary exposure to cadmium and health risk assessment in children - Results of the French infant total diet study.

Besides specific occupational activities or smoking, food is the main route of cadmium exposure for the general population. In France a total diet study previously conducted for adults and children over 3 years old revealed that health concerns due to Cd dietary exposure existed for both adults and children. This study showed that the Cd tolerable weekly intake, based on potential nephrotoxicity effects, is exceeded by a high proportion of children under 3 years old. Nephrotoxicity results from the accumulation of cadmium in the kidney and appears typically after long-term exposure (40-50 years). Despite the exceeding of the tolerable weekly intake observed during the first three years of childhood, due to low body weights compared to adults, the accumulation rate of cadmium is much lower during the whole childhood period (from 0 to 17 years of age) than during adulthood. These data suggest that dietary exposure to cadmium should be reduced for both children and adults to prevent health concerns associated with nephrotoxicity in later life. Moreover, recent literature suggests that Cd can induce other adverse health effects (especially endocrine disruption or neurotoxicity) that could be triggered at even lower doses than those triggering nephrotoxicity.

Levels of lead in foods from the first French total diet study on infants and toddlers.

Infants and toddlers are highly vulnerable to exposure to lead due to its higher absorption in small children than in adults. This study describes the optimisation and validation of a very sensitive method for the determination of low levels of lead in foods mostly consumed by infants and toddlers. This method, based on inductively coupled plasma-mass spectrometry with a programmable temperature cyclonic spray chamber, attained a limit of quantification (LOQ) of 0.6 or 0.9µgPbkg-1 for a liquid or a solid sample, that was improved by a factor 5.6-8.3 compared to the previous method (LOQ: 5µgkg-1). The analytical method was then applied to 291 food samples from the first French total diet study on infants and toddlers. Lead was detected in most samples at relatively low concentrations (range 0.0-16µgkg-1). The highest lead concentrations were mainly found in processed food products (e.g. products containing chocolate).