Long-term dietary exposure to lead in young European children: comparing a pan-European approach with a national exposure assessment.

Long-term dietary exposures to lead in young children were calculated by combining food consumption data of 11 European countries categorised using harmonised broad food categories with occurrence data on lead from different Member States (pan-European approach). The results of the assessment in children living in the Netherlands were compared with a long-term lead intake assessment in the same group using Dutch lead concentration data and linking the consumption and concentration data at the highest possible level of detail. Exposures obtained with the pan-European approach were higher than the national exposure calculations. For both assessments cereals contributed most to the exposure. The lower dietary exposure in the national study was due to the use of lower lead concentrations and a more optimal linkage of food consumption and concentration data. When a pan-European approach, using a harmonised food categorisation system and "European" concentration data, results in a possible health risk related to the intake of an environmental chemical for a certain country, it is advisable to refine this assessment, as part of a tiered approach, using national occurrence data, including an optimised linkage between foods analysed and consumed for that country. In the case of lack of occurrence data, these data can be supplemented with data from the "European" concentration database or by generating additional concentration data at country level.

Harmonisation of food categorisation systems for dietary exposure assessments among European children.

Within the European project called EXPOCHI (Individual Food Consumption Data and Exposure Assessment Studies for Children), 14 different European individual food consumption databases of children were used to conduct harmonised dietary exposure assessments for lead, chromium, selenium and food colours. For this, two food categorisation systems were developed to classify the food consumption data in such a way that these could be linked to occurrence data of the considered compounds. One system served for the exposure calculations of lead, chromium and selenium. The second system was developed for the exposure assessment of food colours. The food categories defined for the lead, chromium and selenium exposure calculations were used as a basis for the food colour categorisation, with adaptations to optimise the linkage with the food colour occurrence data. With this work, an initial impetus was given to make user-friendly food categorisation systems for contaminants and food colours applicable on a pan-European level. However, a set of difficulties were encountered in creating a common food categorisation system for 14 individual food consumption databases that differ in the type and number of foods coded and in level of detail provided about the consumed foods. The work done and the problems encountered in this project can be of interest for future projects in which food consumption data will be collected on a pan-European level and used for common exposure assessments.

Probabilistic modelling of exposure doses and implications for health risk characterization: glycoalkaloids from potatoes.

Potatoes are a source of glycoalkaloids (GAs) represented primarily by alpha-solanine and alpha-chaconine (about 95%). Content of GAs in tubers is usually 10-100 mg/kg and maximum levels do not exceed 200 mg/kg. GAs can be hazardous for human health. Poisoning involve gastrointestinal ailments and neurological symptoms. A single intake of >1-3 mg/kg b.w. is considered a critical effect dose (CED). Probabilistic modelling of acute and chronic (usual) exposure to GAs was performed in the Czech Republic, Sweden and The Netherlands. National databases on individual consumption of foods, data on concentration of GAs in tubers (439 Czech and Swedish results) and processing factors were used for modelling. Results concluded that potatoes currently available at the European market may lead to acute intakes >1 mg GAs/kg b.w./day for upper tail of the intake distribution (0.01% of population) in all three countries. 50 mg GAs/kg raw unpeeled tubers ensures that at least 99.99% of the population does not exceed the CED. Estimated chronic (usual) intake in participating countries was 0.25, 0.29 and 0.56 mg/kg b.w./day (97.5% upper confidence limit). It remains unclear if the incidence of GAs poisoning is underreported or if assumptions are the worst case for extremely sensitive persons.

Cumulative risk assessment of the exposure to organophosphorus and carbamate insecticides in the Dutch diet.

We report the acute cumulative exposure to organophosphorus insecticides (OPs) and carbamates in the Dutch population and young children (1-6 years) via the diet. Residue data were derived from Dutch monitoring programmes performed during 2003-2005, and food consumption levels from the Dutch National Food Consumption Survey 1997/1998. The relative potency factor (RPF) approach was used to cumulate the exposure to OPs and carbamates using acephate and oxamyl as index compound respectively. The exposure was estimated using the probabilistic approach, including unit variability and processing effects. We demonstrate that about 3% of the composite samples analysed for OPs and 0.2% for carbamates contain combinations of these pesticides. The P99.9 of exposure to OPs and carbamates in the total Dutch population equals 23 and 0.64microg/kg BW/d respectively. For young children the corresponding exposure levels are 57 and 1.47microg/kg BW/d. When comparing the P99.9 of exposure with the ARfD, 50 and 9microg/kg BW/d for acephate and oxamyl respectively, there is only a possible health risk for young children. Spinach contributed most to the exposure to OPs in both age groups, followed by orange and mandarin. For carbamates apple (sauce) was the main product determining the exposure.

Analysis of multivariate extreme intakes of food chemicals.

A recently published multivariate Extreme Value Theory (EVT) model is applied to the estimation of population risks associated with dietary intake of pesticides. The objective is to quantify the acute risk of pesticide intake above a threshold and relate it to the consumption of specific primary food products. As an example daily intakes of a pesticide from three foods are considered. The method models and extrapolates simultaneous intakes of pesticide, and estimates probability of exceeding unobserved large intakes. Multivariate analysis was helpful in identifying whether the avoidance of certain food combinations would reduce the likelihood of exceeding a threshold. We argue that the presented method can be an important contribution to exposure assessment studies.

Determination of trichothecenes in duplicate diets of young children by capillary gas chromatography with mass spectrometric detection.

Trichothecenes are mycotoxins produced by several fungal genera, mainly Fusarium species, that can contaminate a wide range of cereals used for human and animal consumption. They are associated with various adverse health effects in animals and humans such as feed refusal, vomiting and immunotoxic effects. A method based on capillary gas chromatography with mass spectrometric detection was developed and validated in-house for the determination of nine trichothecenes in duplicate diets of young children. The trichothecenes were extracted from the sample matrix by water/ethanol (90/10). The extracts were cleaned by means of ChemElut and Mycosep columns. The cleaned extracts were evaporated to dryness and derivatized to trimethylsilyl ethers at room temperature. The residues were dissolved in iso-octane and washed with water. The final extracts were analysed for trichothecenes by GC-MS. The response was linear in the range tested (1-10 microg kg(-1)). Recoveries for the trichothecenes were between 70 and 111%, with the exception of nivalenol, which had a low recovery (34%). The limit of quantification for all trichothecenes was below 0.4 microg kg(-1). Seventy-four food samples from young children collected by 74 respondents in a duplicate diet study were analysed for trichothecenes with the developed method. The mean levels of deoxynivalenol, nivalenol, HT-2 toxin and T-2 toxin were 5.8, 0.3, 0.3 and 0.1 microg kg(-1), respectively. Based on the individual results, dietary intake calculations were made. For deoxynivalenol, the tolerable daily intake of 1 microg kg(-1) body weight was exceeded by nine respondents. For the combined intake of T-2 and HT-2 toxin, the temporary tolerable daily intake of 0.06 microg kg(-1) body weight was exceeded by nine respondents.

Dioxins, dioxin-like PCBs and non-dioxin-like PCBs in foodstuffs: occurrence and dietary intake in The Netherlands.

Data on occurrence of dioxins (polychlorinated dibenzo-p-dioxins [PCDDs] and dibenzofurans [PCDFs]), dioxin-like PCBs (polychlorinated non-ortho and mono-ortho biphenyls) and non-dioxin-like PCBs (as represented by the so-called indicator-PCBs: congeners 28, 52, 101, 118, 138, 153 and 180) in food products consumed in The Netherlands that were collected in measurement programs carried out during 1998 and 1999, and combined with food consumption data to assess the dietary intake of these persistent food contaminants. The estimated median life-long-averaged intake of the sum of dioxins and dioxin-like PCBs in the population is 1.2 pg WHO-TEQ (toxic equivalents) per kg body weight (bw) per day, while the estimated median life-long-averaged intake of indicator-PCBs is 5.6 ng per kg bw per day. The contribution of different food groups to the total intake of both dioxins + dioxin-like PCBs and non-dioxin-like PCBs is fairly uniformly distributed over the foods consumed: meat products (23% and 27%, respectively), dairy products (27% and 17%, respectively), fish (16% and 26%, respectively), eggs (4% and 5%, respectively), vegetable products (13% and 7%, respectively), and industrial oils and fats (17% and 18%, respectively). Compared with earlier intake estimations the present estimation shows a continued reduction in the intake of dioxins as well as PCBs. This reduction is related to the decrease in the concentration of these substances in the majority of foodstuffs. Nevertheless, a small part of the population still has a rather high life-long averaged intake: 8% of the population is exposed to intake levels above the tolerable weekly intake for dioxins and dioxin-like PCBs of 14 pg WHO-TEQ per kg bw per week, as recently derived by the Scientific Committee on Food of the European Commission. For the non-dioxin-like PCBs an internationally accepted maximum intake level is still lacking. However, to provide risk managers with a health-based guideline to prevent health effects of exposure to non-dioxin-like PCBs, the (international) derivation of a tolerable daily intake is recommended. Monitoring the dietary intake of PCBs is just as important as monitoring the intake of dioxins and dioxin-like PCBs, and attempts to decrease the exposure to both compound classes need continuous attention.

Validation of a probabilistic model of dietary exposure to selected pesticides in Dutch infants.

A probabilistic model for dietary exposure to pesticides was validated. For this, we evaluated the agreement of dietary exposure to six pesticides as estimated with the model with exposures measured in duplicate diet samples (='real intake') and those calculated with the point estimate. To calculate the exposure with the model and point estimate, consumption data of the duplicate diet survey and pesticide residue measurements from Dutch monitoring programmes in 2000 and 2001 were used. The model was considered validated when the outcome was both higher than the real intake and lower than the point estimate. Results showed that exposures estimated with the model were closer to the real intake than those of the point estimate, and that the model outcome was lower than the point estimate. Furthermore, it was shown that the probabilistic approach can address the exposure to a pesticide via the consumption of different food products, while the point estimate only estimates the exposure through the consumption of one product. The model validated is a valuable asset when estimating the dietary exposure to pesticides in both the authorization of new pesticides and the evaluation of exposures using monitoring data.

Acrylamide exposure from foods of the Dutch population and an assessment of the consequent risks.

At the end of April 2002, the Swedish Food Administration reported the presence of acrylamide in heat treated food products. Acrylamide has been shown to be toxic and carcinogenic in animals, and has been classified by the WHO/IARC among others as 'probably carcinogenic for humans'. The purposes of this study were firstly to analyse acrylamide contents of the most important foods contributing to such exposure, secondly, to estimate the acrylamide exposure in a representative sample of the Dutch population, and thirdly to estimate the public health risks of this consumption. We analysed the acrylamide content of foods with an LC-MS-MS method. The results were then used to estimate the acrylamide exposure of consumers who participated in the National Food Consumption Survey (NFCS) in 1998 (n=6250). The exposure was estimated using the probabilistic approach for the total Dutch population and several age groups. For 344 food products, acrylamide amounts ranged from <30 to 3100 microg/kg. Foods with the highest mean acrylamide amounts were potato crisps (1249 microg/kg), chips (deep-fried) (351 microg/kg), cocktail snacks (1060 microg/kg), and gingerbread (890 microg/kg). The mean acrylamide exposure of the NFCS participants was 0.48 microg/kg bw/day. Risk of neurotoxicity is negligible. From exposure estimations it appears that the additional cancer risk might not be negligible.

Intake of nitrate and nitrite and the risk of gastric cancer: a prospective cohort study.

The association between the intake of nitrate or nitrite and gastric cancer risk was investigated in a prospective cohort study started in 1986 in the Netherlands, of 120,852 men and women aged 55-69 years. At baseline, data on dietary intake, smoking habits and other covariates were collected by means of a self-administered questionnaire. For data analysis, a case-cohort approach was used, in which the person-years at risk were estimated from a randomly selected subcohort (1688 men and 1812 women). After 6.3 years of follow-up, 282 microscopically confirmed incident cases of stomach cancer were detected: 219 men and 63 women. We did not find a higher risk of gastric cancer among people with a higher nitrate intake from food [rate ratio (RR) highest/lowest quintile = 0.80, 95% CI 0.47-1.37, trend-P = 0.18], a higher nitrate intake from drinking water (RR highest/lowest quintile = 0.88, 95% CI 0.59-1.32, trend-P = 0.39) or a higher intake of nitrite (RR highest/lowest quintile = 1.44, 95% CI 0.95-2.18, trend-P = 0.24). Rate ratios for gastric cancer were also computed for each tertile of nitrate intake from foods within tertiles of vitamin C intake and intake of beta-carotene, but no consistent pattern was found. Therefore, our study does not support a positive association between the intake of nitrate or nitrite and gastric cancer risk.

Nutritional status of infants aged 4 to 18 months on macrobiotic diets and matched omnivorous control infants: a population-based mixed-longitudinal study. II. Growth and psychomotor development.

A mixed-longitudinal study was carried out in the 1985 Dutch birth cohort of macrobiotic infants aged 4-18 months (n = 53) and 57 omnivorous control infants matched for month of birth, sex, parity, educational level of the father and the residential area. Study methods included regular anthropometric measurements and a psychomotor testing. Reported birth weight was 180 g lower in the macrobiotic group than in the control group and was positively associated with maternal weight increase during pregnancy. Between 4 and 18 months of age, mean values for all anthropometric parameters were considerably lower in the macrobiotic infants. From birth to 4 months, weight gain was less in macrobiotic infants, and from 6 months the rate of growth in weight and length decreased further, reaching its lowest value between 8 and 14 months of age. A similar pattern was also observed for other anthropometric parameters. Between 8 and 14 months, arm circumference showed an absolute decrease. During this period, increase in arm muscle mass in the macrobiotic group was only half of that in the control group. From 14 months of age, growth stabilized parallel to the 10th percentile of the Dutch references. Gross motor and language development were also slower in the macrobiotic infants. The paediatrician observed major wasting of skin and muscles in 30 per cent of them. The growth rate for weight and arm circumference was independently associated with the energy intake and the protein content of the macrobiotic diet. Growth in length was positively associated with protein content of the diet, but not with energy intake.

Do children on macrobiotic diets show catch-up growth? A population-based cross-sectional study in children aged 0-8 years.

Children who are fed alternative and especially macrobiotic diets have been reported to be smaller and weigh less than their peers fed omnivorous diets. To answer the questions: at what age does growth in children on macrobiotic diets slow down, and is there any return to standards later in childhood, a cross-sectional anthropometric study was performed in the Dutch macrobiotic child population aged 0-8 years (n = 243). Addresses were obtained from macrobiotic organizations and from families already participating in the study. Food habits were checked by a structured food frequency questionnaire. Anthropometric measurements included weight, height, mid-upper arm circumference and triceps and subscapular skinfolds. For each sex, age curves were constructed in comparison to standards. For selected age intervals, standard deviation scores (SDS) were tested for differences from the reference after accounting for confounding variables in a multiple regression model. Reported birth weight was 150 g lower than the Dutch reference; birth weight was positively associated with the consumption frequency of dairy products and fish. During the first 6-8 months of life, SDS were not different from the standard except for arm circumference and skinfolds. From 6-8 months onwards, growth stagnation occurred in both sexes, but was most marked in girls. A minimum level of 1 to 1.5 SD below the P50 of the reference was reached by the age of 18 months. Between 2 and 4 years a partial return towards the P50 occurred for arm circumference and, in boys only, for weight and skinfolds, but not for height. SDS of weight, height and arm circumference were higher in children from families with regular consumption of dairy products than in children from families avoiding dairy products.