Probabilistic acute dietary exposure assessments to captan and tolylfluanid using several European food consumption and pesticide concentration databases

Probabilistic dietary acute exposure assessments of captan and tolylfluanid were performed for the populations of the Czech Republic, Denmark, Italy, the Netherlands and Sweden. The basis for these assessments was national databases for food consumption and pesticide concentration data harmonised at the level of raw agricultural commodity. Data were obtained from national food consumption surveys and national monitoring programmes and organised in an electronic platform of databases connected to probabilistic software. The exposure assessments were conducted by linking national food consumption data either (1) to national pesticide concentration data or (2) to a pooled database containing all national pesticide concentration data. We show that with this tool national exposure assessments can be performed in a harmonised way and that pesticide concentrations of other countries can be linked to national food consumption surveys. In this way it is possible to exchange or merge concentration data between countries in situations of data scarcity. This electronic platform in connection with probabilistic software can be seen as a prototype of a data warehouse, including a harmonised approach for dietary exposure modelling.     

Harmonisation of food consumption data format for dietary exposure assessments of chemicals analysed in raw agricultural commodities

In this paper, we present an approach to format national food consumption data at raw agricultural commodity (RAC) level. In this way, the data is both formatted in a harmonised way given the comparability of RACs between countries, and suitable to assess the dietary exposure to chemicals analysed in RACs at a European level. In this approach, consumption data needs to be converted to edible part of RAC (e-RAC) level using a RAC conversion database. To subsequently use this data in exposure assessments, both e-RACs and RACs analysed in chemical control programmes should be classified via a uniform system. Furthermore, chemical concentrations in RACs may need to be converted to e-RAC level using processing factors. To illustrate the use of this approach, we describe how the Dutch RAC conversion database was used to convert consumption data of four national consumption surveys to e-RAC level, and the use of the FAO/WHO Codex Classification system of Foods and Animal Feeds to harmonise the classification. We demonstrate that this approach works well for pesticides and glycoalkaloids, and is an essential step forward in the harmonisation of risk assessment procedures within Europe when addressing chemicals analysed in RACs by all national food control systems.     

Comparison of different exposure assessment methods to estimate the long-term dietary exposure to dioxins and ochratoxin A

Long-term exposures to dioxins (PCCD/F and dioxin-like PCBs) and ochratoxin A were calculated using food consumption data of the European concise database combined with concentration data of the Netherlands (NL) using a deterministic approach. To refine these assessments, exposures were also calculated using three long-term exposure models, observed individual means (OIM), Iowa State University Foods (ISUF), and betabinomial-normal (BBN) models, combined with individual food consumption data of NL. BBN and ISUF correct the variation in long-term exposure for the within-person variation, whereas OIM calculates the mean exposure over the days in the food consumption survey. Exposures obtained with the concise database were highest, and those obtained with OIM higher than with BBN and ISUF. Contribution of the major sources of exposure differed between the concise database and the three models. Given the constraints of the concise database, exposures obtained with this database should be interpreted as a first tier assessment. Preferably, refined assessments using models that correct the variation in long-term exposure for the within-person variation combined with individual food consumption data and national concentration data should be used to assess the long-term exposure. We recommend the use of BBN since it can model exposure distributions that depend on covariates.     

Toxicity of so-called edible hijiki seaweed (Sargassum fusiforme) containing inorganic arsenic

The UK Food Standards Agency and its counterparts in other countries have warned consumers not to eat hijiki (Sargassum fusiforme; synonym Hizikia fusiformis), a Sargasso seaweed, because it contains large amounts of inorganic arsenic. We investigated dietary exposure of hijiki in weaning male F344/N rats fed an AIN-93G diet supplemented with 3% (w/w) hijiki powder for 7 weeks, compared with those fed only an AIN-93G diet. Body weight, body temperature, blood and tissue arsenic concentrations, plasma biochemistry and hematological parameters were measured. We found that feeding rats a 3% hijiki diet led to a marked accumulation of arsenic in blood and tissues, and evoked a high body temperature and abnormal blood biochemistry including elevated plasma alkaline phosphatase activity and inorganic phosphorus, consistent with arsenic poisoning. These findings should prompt further investigations to identify the health hazards related to consumption of hijiki and related Sargassum species in humans.     

A refined approach to estimate exposure for use in calculating the Maximum Residue Limit of veterinary drugs

Maximum Residue Limits (MRLs) are standards that represent the maximum residue concentration expected to be found if a veterinary drug is administered according to good practice in the use of veterinary drugs (GVP). MRLs are established only where the exposure to residues in food resulting from particular use patterns of the veterinary drug pass a public health risk assessment. The current model diet as used by major regulators overstates mean consumption of food for populations when compared to results from food surveys of actual consumption. Exposure to residues is overestimated when calculating long-term (chronic) exposure using the model diet leading to the risk to consumers being overstated. Additionally the model diet underestimates the size of large portions eaten by the group of consumers that eat large quantities of a particular food in a single meal potentially leading to understating of risks associated with exposure to residues of drugs that produce an adverse effect after a single exposure. A revision of dietary consumption figures is proposed that will better match the consumption figures used in point-estimates of dietary exposure to the timeframe for consumption that is relevant to the reference dose.     

Exposure to dioxin-like pollutants via different food commodities in Swedish children and young adults

The dietary intake of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) in terms of toxic equivalents (TEQs) was investigated in Swedish children and young adults. Exposure was estimated from concentration data of six groups of individual food commodities (meat, fish, dairy products, egg, edible fats and other foodstuff) combined with food intake data from a 7-day record book obtained from 670 individuals aged 1–24 years. The results showed that Swedish boys and girls, up to the age of ten, had a median TEQ intake that exceeded the tolerable daily intake (TDI) of 2 pg TEQ/kg body weight. Children exceeding the TDI varied from almost all individuals among the youngest children to about 20% among young men and women. Dairy and fish products were the main sources of exposure for the average child, accounting for 59% of the total TEQ intake. The individuals most highly exposed were, on the other hand, characterized by a high consumption of fish. Since children constitute a vulnerable group, results obtained from the present study show that it is essential to perform age specific dietary intake assessments of pollutants and more carefully consider sensitive and/or highly exposed groups in the population in the risk management processes.     

A probabilistic model for simultaneous exposure to multiple compounds from food and its use for risk-benefit assessment.

A model is presented which allows to quantify the simultaneous distribution of the exposure to two compounds, for example a health-risk and a health promoting compound. The model considers the total dietary intake, and can be used as a first step to study the effects on the balance between risks and benefits following changes in the consumption pattern. The exposure is modelled separately for intake probabilities using a betabinomial model, and for intake amounts using a lognormal model, and these parts are afterwards integrated by Monte Carlo simulation. The model is illustrated using the risk-benefit case of dioxins and the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). High concentrations of both the health adverse compounds and the health promoting compounds are simultaneously present in fatty fish. Calculated exposures were compared with intake limits: the adequate intake for EPA+DHA and the tolerable daily intake (TDI) for dioxins. We estimate the probability that dioxin exposure is below TDI, the probability that EPA+DHA exposure is above the adequate intake, and the probability that both conditions occur simultaneously. We also model the dependence of these probabilities on age. In the studied population the exposure to both compounds is almost completely below the limits. A scenario study in which meat consumption was replaced by fatty fish consumption shows an increase in the fraction of the population with the recommended intake of EPA+DHA, however also the fraction of the population exceeding the TDI for dioxins is increased. For the example scenario the optimal amount of fatty fish consumption is derived.     

A statistical reevaluation of the data used in the Lanphear et al. () pooled-analysis that related low levels of blood lead to intellectual deficits in children

Abstract

A pooled-analysis by Lanphear et al. (2005) of seven cohort studies of the association between blood lead (BPb) concentrations in children and measures of their intelligence concluded that “environmental lead exposure in children who have maximal blood lead levels <7.5?μg/dL is associated with intellectual deficits.” This study has played a prominent role in shaping the public understanding of the effects upon children’s IQ of low BPb exposures (e.g., BPb?≤?10?μg/dL). Here we present a reanalysis of the data used by Lanphear et al. to evaluate the robustness of their conclusions. Our analysis differed from that of Lanphear et al. primarily in how we controlled for non-lead variables (allowing a number of them to be site-specific), how we defined summary measures of BPb exposure, and in how we decided which BPb measures and transformations best modeled the data. We also reproduced the Lanphear et al. analysis. Although we found some small errors and questionable decisions by Lanphear et al. that, taken alone, could cause doubt in their conclusions, our reanalysis tended to support their conclusions. We concluded that there was statistical evidence that the exposure-response is non-linear over the full range of BPb evaluated in these studies, which implies that, for a given increase in blood lead, the associated IQ decrement is greater at lower BPb levels. However at BPb below 10?µg/dL, the exposure-response is adequately modeled as linear. We also found statistical evidence for an association with IQ among children who had maximal measured BPb levels ≤7?μg/dL, and concurrent BPb levels as low as ≤5?μg/dL.     

Estimation of ochratoxin A in some Turkish populations: An analysis in urine as a simple,sensitive and reliable biomarker

In this study, ochratoxin A (OTA) occurrence and level in human urine samples, collected from four different regions of Turkey was analyzed by NaHCO₃ dilution, immunoaffinity column clean-up and high-performance liquid chromatography with fluorescent detection. For the repeatability of the method, RSD (%) values were found between 3.83 and 8.86, for the accuracy, the recovery values were found between 85.7% and 110.5% and limit of detection and limit of quantification of the method were measured as 0.006 and 0.018 ng mL⁻¹ respectively. For the analysis, first morning urine samples were collected and the results were adjusted with creatinine levels. From the total collected samples of 233 larger amounts of 83% was contaminated with OTA. Among the calculated to be OTA levels, positive sample rate, average OTA amount and the highest contamination was found in Ankara. (Positive sample rate; 90.1%, average OTA concentration; 14.34 ng g⁻¹ creatinine and highest OTA value; 75.60 ng g⁻¹ creatinine). In order to define the exposure profile of OTA in human a questionnaire was conducted among the voluntaries as well. But related to the gender, age, dietary habits, coffee consumption, smoking and alcohol habits of the volunteers, no correlation was found with the OTA exposure.     

Heavy metals concentrations in fish and shellfish from eastern Mediterranean Sea: Consumption advisories

The present study evaluate concentrations of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), manganese (Mn), nickel (Ni), vanadium (V) and zinc (Zn) in fish and shellfish from the Gulf of Catania. Heavy metal analysis was carried on with an ICP-MS, and consumption rates advisory for minimizing chronic systemic and non cancer endpoints in child and adults have been estimated. Among metals investigated, only Cd and Pb have a limit set by European Community for human consumption, and the thresholds were not been exceeded in analyzed species. The As, toxic in its inorganic form, have not a regulatory limit yet, but the Environmental Protection Agency and the World Health Organization provide a reference dose, a cancer slope factor and a tolerable intake, applicable in the risk factors assessment. Arsenic target hazard quotient (THQ) values, suggest that human should minimizing meals/week of analyzed species to avoid deleterious effect during lifetime, furthermore, with As cancer risk assessment, for most of the fish, the risk for cancer is greater than the acceptable lifetime risk of 10^–5. Our results give important finding about the consumption limits on certain metals, especially for As, all for minimizing potential health risks in population.     

The Yugoslavia Prospective Lead Study: contributions of prenatal and postnatal lead exposure to early intelligence

To investigate associations between the timing of lead (Pb) exposure on early intelligence, we examined the results of psychometric evaluations at ages 3, 4, 5, and 7 years, from 442 children whose mothers were recruited during pregnancy from a smelter town and a non-lead-exposed town in Yugoslavia. We compared the relative contribution of prenatal blood lead (BPb) with that of relative increases in BPb in either the early (0–2 years) or the later (from 2 years on) postnatal period to child intelligence measured longitudinally at ages 3 and 4 (McCarthy GCI), 5 (Wechsler Preschool and Primary Scale of Intelligence-Revised, WPPSI-R IQ), and 7 (Wechsler Intelligence Scale for Children-version III, WISC-III IQ), controlling for: Home Observation for Measurement of the Environment (HOME) quality; maternal age, intelligence, education, and ethnicity; and birthweight and gender. Elevations in both prenatal and postnatal BPb were associated with small decrements in young children's intelligence.     

Cognitive development and low-level lead exposure in poly-drug exposed children

The impact of early postnatal lead exposure measured at age 4 on children's IQ and academic achievement at and 11 years of age was examined. The sample consisted of 278 inner-city, primarily African American children who were polydrug exposed prenatally. Regression analyses indicated a linear effect of lead exposure on outcomes and no moderating effects of polydrug exposure. An IQ loss of about 4.1–5.4 Full Scale IQ points was estimated for each 10 µg/dL increase in blood lead level at ages 4, 9, and 11 years as a function of blood lead level at age 4. Decrements in scores on tests of non-verbal reasoning were consistently associated with higher lead levels at age 4, while verbal decrements became apparent only at age 11. Lower reading summary scores at 9 and 11 years were consistently associated with higher lead exposure, while decrements in mathematics were not apparent until 11 years. Subgroup analyses on children with blood lead levels < 10 μg/dL showed detrimental lead effects even at the 5 μg/dL level, providing additional evidence of adverse effects occurring at blood lead levels below the current 10 μg/dL public health blood lead action level.     

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).     

Dietary exposure to essential and toxic trace elements from a Total diet study in an adult Lebanese urban population

This study assesses, by the Total diet study approach, the adequacy of micronutrient intake (Co, Cu, Fe, Mn, Ni, Zn) and the dietary exposure of a Lebanese adult urban population to two toxic elements (Cd, Pb). The foods that made up the average ‘total diet’ were derived from a previous individual consumption survey. A total of 1215 individual foods were collected, prepared and cooked prior to analysis. Analytical quantification was performed using inductively coupled plasma mass spectrometry. Average daily intakes of Co (11.4 μg/day), Cu (1104.19 μg/day), Fe (13.00 mg/day), Mn (2.04 mg/day), Ni (126.27 μg/day) and Zn (10.97 mg/day) were below toxicological reference values and were found to satisfy nutritional recommendations, except for manganese in men and iron in women. Average dietary exposure to Pb and Cd represented 3.2% and 21.7% of the respective provisional tolerable weekly intakes. Estimates of dietary intakes of iron appeared to be inadequate for 63% of adult women. These findings should constitute a current measure of assessing the adequacy and safety of foods consumed in Lebanon and may be a basis for future monitoring studies.     

Assessment of rare dietary risks based on analysis of food combinations

Probabilistic methods, in particular Monte Carlo methods, have become widely used in assessment of dietary risks from plant protection products. However, if the critical exposure occurs rarely, estimating its probability with commonly used Monte Carlo approaches can require an unrealistically big number of iterations. A simple method proposed in this paper, referred to as food combination analysis (FCA), finds out subsets of input values necessary for occurrence of a critical exposure event. In particular, for a critical event to occur consumption of a certain combination of contaminated foods could be required. Sometimes by finding the probability that such a food combination is consumed one could directly get an acceptable estimate of the risk, without Monte Carlo simulations. The method performs especially well if available data sets of consumed amounts of foods and residue concentrations of a chemical contain a large fraction of zeros. Based on a literature example, it is shown that the probability of the critical exposure estimated with the FCA could be more than 10 times lower than the estimate of a Monte Carlo approach with 50,000 iterations. The present approach also provides a platform for adaptation and development of more sophisticated methods to estimate low dietary risks.     

Risk assessment of dietary exposure to methylmercury in fish in the UK

Risk assessment of chemicals in food is generally based upon the results of toxicological studies in laboratory animals, allowing for uncertainties relating to interspecies differences, human variability, and gaps in the database. Use of quantitative human data is preferable if available, as in the example of methylmercury. Methylmercury is a neurotoxic environmental contaminant, for which fish is the main source of dietary exposure. Human data from poisoning incidents and epidemiological studies have been used by expert committees to derive a guideline intake level for methylmercury, based on the susceptibility of the most sensitive lifestage, the developing fetus. In the UK, an expert group of nutritionists and toxicologists was formed to review the benefits and risks associated with fish consumption. A formal risk-benefit analysis was not possible because the nutritional data were not sufficiently quantitative. The Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT), therefore, modified the risk assessment approach to derive different guideline intake levels for different subgroups of the population. The COT opinion was used to provide targeted advice on how much fish can be consumed without undue risk from the contaminants. Consumption by adults of one weekly portion (140 g) of shark, swordfish or marlin, would lead to an exceedance of the guideline intake for methylmercury of 40-90%, set to protect the developing fetus, without considering intake from the rest of the diet. Pregnant women and women who may become pregnant within 1 year were, therefore, advised to avoid consumption of these species. Intakes in other adults would be within a higher guideline intake, set to protect groups of the population other than the developing fetus. However, consumption by children of one weekly portion of these species could lead to an exceedance of this guideline intake by up to 60%, without considering intake from the rest of the diet. It was, therefore, advised that consumption of these species by children should be avoided.     

Prenatal exposure to lead and cognitive deficit in 7- and 14-year-old children in the presence of concomitant exposure to similar molar concentration of methylmercury

Few studies have examined the effects of mixed metal exposures in humans. We have evaluated the effect of prenatal lead exposure in a Faroese birth cohort in the presence of similar molar-level exposure to methylmercury. A cohort of 1022 singleton births was assembled in the Faroe Islands during 1986–1987 from whom lead was measured in cord-blood. A total of 896 cohort subjects participated in a clinical examination at age 7 and 808 subjects in a second examination at age 14. We evaluated the association between cord-blood lead concentrations and cognitive deficits (attention/working memory, language, visuospatial, and memory) using multiple regression models. Overall, the lead concentration showed no clear pattern of association. However, in subjects with a low methylmercury exposure, after inclusion of statistical interaction terms, lead-associated adverse effects on cognitive functions were observed. In particular, higher cord-blood lead was associated with a lower digit span forward score on the Wechsler Intelligence Scale for Children-Revised (WISC-R) [beta = ?1.70, 95% confidence interval (CI): ?3.12 to ?0.28] at age 7 and a lower digit span backward score on the WISC-R (beta = ?2.73, 95%CI: ?4.32 to ?1.14) at age 14. Some interaction terms between lead and methylmercury suggested that the combined effect of the exposures was less than additive. The present study indicates that adverse effects of exposure may be overlooked if the effects of a co-pollutant are ignored. The present study supports the existence of adverse effects on cognitive functions at prenatal lead exposures corresponding to an average cord-blood concentration of 16 μg/L.     

Teeth and blood lead levels in Egyptian schoolchildren: relationship to health effects

The objective of this work was to study teeth and blood lead levels in Egyptian schoolchildren and to relate lead levels to sociodemographic and environmental factors, the degree of urbanization and suspected manifestations of possible lead exposure. The study was conducted on 60 children aged 6-12 years: 30 children living in an urban area at Alexandria City and 30 children living in a rural area at Kafr El-Sheikh Province. Both groups are matched for age and gender. Every child was subjected to history taking, clinical examination and IQ measurements. Laboratory investigations included measuring teeth and blood lead levels, haemoglobin, serum iron and total iron binding capacity. The results showed that the mean blood lead level of children in Alexandria was significantly higher than that of the children in Kafr El-Sheikh; also 56.7% and 6.7% of children from Alexandria and Kafr El-Sheikh had a blood lead level of >20 microg dl(-1), with the most frequent symptoms of headache, arthralgia and lack of school interest. The children in Alexandria had significantly lower mean teeth lead and haemoglobin levels than those of the Kafr El-Sheikh group. A history of wrapping sandwiches in newspapers, age and distance between the home and school were significant predictors of lead exposure. These findings support the concept that teeth lead concentration may be a valid addition to the indicators used for assessment of the body burden of environmental lead. In addition, children living in urban areas such as Alexandria need special consideration regarding protection from lead exposure, as well as teeth and blood lead evaluation.     

Retrospective and Current Risks of Mercury to Panthers in the Florida Everglades

Florida panthers are an endangered species inhabiting south Florida. Hg has been suggested as a causative factor for low populations and some reported panther deaths, but a quantitative assessment of risks has never been performed. This study quantitatively evaluated retrospective (pre-1992) and current (2002) risks of chronic dietary Hg exposures to panthers in the Florida Everglades. A probabilistic assessment of Hg risks was performed using a dietary exposure model and Latin Hypercube sampling that incorporated the variability and uncertainty in ingestion rate, diet, body weight, and mercury exposure of panthers. Hazard quotients (HQs) for retrospective risks ranged from less than 0.1-20, with a 46% probability of exceeding chronic dietary thresholds for methylmercury. Retrospective risks of developing clinical symptoms, including ataxia and convulsions, had an HQ range of <0.1-5.4 with a 17% probability of exceeding an HQ of 1. Current risks were substantially lower (4% probability of exceedences; HQ range <0.1-3.5) because of an estimated 70-90% decline in Hg exposure to panthers over the last decade. Under worst case conditions of panthers consuming only raccoons from the most contaminated area of the Everglades, current risks of developing clinical symptoms that may lead to death was 4.6%. Current risks of mercury poisoning of panthers with a diversified diet was 0.1% (HQ range of <0.1-1.4). The results of this assessment indicate that past Hg exposures likely adversely affected panthers in the Everglades, but current risks of Hg are low.