Estimation of exposure to food packaging materials. 1: Development of a food-packaging database

A food-packaging database was developed to provide qualitative information on the types of packaging materials used for foods. Packaging information was collected from a sample of 594 children aged 5-12 years as part of a national children's food survey carried out in Ireland during 2003-04. All the food packaging collected during the survey was forwarded to the coordinating centre for further analysis and entry into the Irish Food Packaging Database. The database was created in Microsoft Access® and stored information on: the brand of the food, the packaging type, the unit weight, the contact layer, the European Union food type (i.e. aqueous, acidic, alcoholic or fatty) and other relevant parameters. Of the 5551 different brand foods consumed by children in the food survey, packaging information was collected on 3441 (62%). As some brand foods had different unit weights and packaging formats, there was duplication of some brand foods in the database to account for this fact. Therefore, there were 3672 packaging entries in the database. Of these, plastics were the most common packaging contact layer (n = 2874, 78.3%). Multimaterial multilayers with a plastic contact layer accounted for 459 (12.5%) entries. Polyethylene was the most frequently used contact layer (n = 941), with polypropylene a close second (n = 809). This database is unique in Europe for the quality and amount of food packaging information it contains and could be used to develop packaging use factors for a more refined exposure assessment to food packaging materials in the European Union.     

Development of a new modelling tool (FACET) to assess exposure to chemical migrants from food packaging

The approach used to obtain European Union-wide data on the usage and concentration of substances in different food packaging materials is described. Statistics were collected on pack sizes and market shares for the different materials used to package different food groups. The packaging materials covered were plastics (both flexible and rigid), metal containers, light metal packaging, paper and board, as well as the adhesives and inks used on them. An explanation as to how these data are linked in various ways in the FACET exposure modelling tool is given as well as an overview of the software along with examples of the intermediate tables of data. The example of bisphenol A (BPA), used in resins that may be incorporated into some coatings for canned foodstuffs, is used to illustrate how the data in FACET are combined to produce concentration distributions. Such concentration distributions are then linked probabilistically to the amounts of each food item consumed, as recorded in national food consumption survey diaries, in order to estimate exposure to packaging migrants. Estimates of exposure are at the level of the individual consumer and thus can be expressed for various percentiles of different populations and subpopulations covered by the national dietary surveys.     

Assessing the safety of co-exposure to food packaging migrants in food and water using the maximum cumulative ratio and an established decision tree

Food contact materials can release low levels of multiple chemicals (migrants) into foods and beverages, to which individuals can be exposed through food consumption. This paper investigates the potential for non-carcinogenic effects from exposure to multiple migrants using the Cefic Mixtures Ad hoc Team (MIAT) decision tree. The purpose of the assessment is to demonstrate how the decision tree can be applied to concurrent exposures to multiple migrants using either hazard or structural data on the specific components, i.e. based on the acceptable daily intake (ADI) or the threshold of toxicological concern. The tree was used to assess risks from co-exposure to migrants reported in a study on non-intentionally added substances (NIAS) eluting from food contact-grade plastic and two studies of water bottles: one on organic compounds and the other on ionic forms of various elements. The MIAT decision tree assigns co-exposures to different risk management groups (I, II, IIIA and IIIB) based on the hazard index, and the maximum cumulative ratio (MCR). The predicted co-exposures for all examples fell into Group II (low toxicological concern) and had MCR values of 1.3 and 2.4 (indicating that one or two components drove the majority of the mixture’s toxicity). MCR values from the study of inorganic ions (126 mixtures) ranged from 1.1 to 3.8 for glass and from 1.1 to 5.0 for plastic containers. The MCR values indicated that a single compound drove toxicity in 58% of the mixtures. MCR values also declined with increases in the hazard index for the screening assessments of exposure (suggesting fewer substances contributed as risk potential increased). Overall, it can be concluded that the data on co-exposure to migrants evaluated in these case studies are of low toxicological concern and the safety assessment approach described in this paper was shown to be a helpful screening tool.     

A review of dietary exposure and toxicological information on epoxidised soybean oil (ESBO) in food-contact applications

ABSTRACT

Plasticisers have a long history of use in the industrial manufacture and processing of polymers for the purpose of increasing the flexibility and strength of the material. Approximately, 80–90% of the plasticiser market is devoted to the production of PVC, a highly versatile thermoplastic used to produce both rigid and flexible articles. Many types of plasticisers, including ortho-phthalate esters (OPE), can be added to PVC to impart flexibility. Recently, alternatives to OPEs, such as epoxy esters and aliphatic adipates, are becoming more prevalent for use in PVC-based food-contact articles. Epoxidised soybean oil (ESBO) is used as a plasticiser in flexible PVC for many food-contact articles, including food packaging and food processing equipment, from which it can potentially migrate into food and become a component of an individual’s daily diet. The purpose of this review is to provide an update on the US dietary exposure and toxicological information on ESBO used in PVC-based food-contact articles. The cumulative dietary concentration (CDC) and cumulative estimated daily intake (CEDI) for ESBO from its use as a plasticiser in PVC-based food-contact articles (i.e. gaskets for glass jar lids and film wraps) was calculated to be 2.6 mg/kg (i.e. ppm) and 0.13 mg/kg bw/d, respectively, for the general population. Some regulatory agencies have reported safety levels for ESBO, and the most conservative no observed adverse effect level (NOAEL) was identified to be 100 mg/kg bw/d (i.e. 2000 ppm) based on a two-year feeding study in rats. The current CEDI is well below these levels, supporting the safe use of ESBO in food-contact applications.     

Consumer exposure to substances in plastic packaging. I. Assessment of the contribution of styrene from yogurt pots

A generic methodology for the assessment of consumer exposure to substances migrating from packaging materials into foodstuffs during storage is presented. Consumer exposure at the level of individual households is derived from the probabilistic modeling of the contamination of all packed food product units (e.g. yogurt pot, milk bottle, etc.) consumed by a given household over 1 year. Exposure of a given population is estimated by gathering the exposure distributions of individual households to suitable weights (conveniently, household sizes). Calculations are made by combining (i) an efficient resolution of migration models and (ii) a methodology utilizing different sources of uncertainty and variability. The full procedure was applied to the assessment of consumer exposure to styrene from yogurt pots based on yearly purchase data of more than 5400 households in France (about 2 million yogurt pots) and an initial concentration c₀ of styrene in yogurt pot walls, which is assumed to be normally distributed with an average value of 500 mg kg^-1 and a standard deviation of 150 mg kg^-1. Results are discussed regarding both sensitivity of the migration model to boundary conditions and household practices. By assuming a partition coefficient of 1 and a Biot number of 100, the estimated median household exposure to styrene ranged between 1 and 35 µg day^-1 person^-1 (5th and 95th percentiles) with a likely value of 12 µg day^-1 person^-1 (50th percentile). It was found that exposure does not vary independently with the average consumption rate and contact times. Thus, falsely assuming a uniform contact time equal to the sell-by-date for all yogurts overestimates significantly the daily exposure (5th and 95th percentiles of 2 and 110 µg day^-1 person^-1, respectively) since high consumers showed quicker turnover of stock.     

New hierarchical classification of food items for the assessment of exposure to packaging migrants: use of hub codes for different food groups

This paper describes development work undertaken to expand the capabilities of an existing two-dimensional probabilistic modelling approach for assessing dietary exposure to chemicals migrating out of food contact materials. A new three-level hub-coding system has been devised for coding different food groups with regards to their consumption by individuals. The hub codes can be used at three different levels representing a high, medium and low level of aggregation of individual food items. The hub codes were developed because they have a greater relevance to packaging migration than coding used (largely and historically) for nutritional purposes. Also, the hub codes will assist pan-europeanization of the exposure model in the future, when up to 27 or more different food coding systems from 27 European Union Member States will have to be assimilated into the modelling approach. The applicability of the model with the new coding system has been tested by incorporating newly released 2001 UK consumption data. The example used was exposure to a hypothetical migrant from coated metal packaging for foodstuffs. When working at the three hierarchical levels, it was found that the tiered approach gave conservative estimates at the cruder level of refinement and a more realistic assessment was obtained as the refinement progressed. The work overall revealed that changes in eating habits over time had a relatively small impact on estimates of exposure. More important impacts are changes over time in packaging usage, packaging composition and migration levels. For countries like the UK, which has sophisticated food consumption data, it is uncertainties in these other areas that need to be addressed by new data collection.     

Dietary exposure to chemical migrants from food contact materials: A probabilistic approach

A two-dimensional probabilistic model has been developed to estimate the short-term dietary exposure of UK consumers to migrants from food packaging materials. The current EU approach uses a default scenario of assuming that all individuals are 60 kg weight and consume 1 kg of food packaged in the material of interest per day. Using four UK National Dietary and Nutrition Surveys comprising 4-7 day dietary records for different age groups and survey years, a sample representative of the UK population has been obtained consuming around 4200 different food items. Each survey provides records for around 2000 individuals and supplies detailed information on the consumption of food and data on sex, height and socio-economic status which may be used to analyse the exposure of selected groups within the community. As a result we are able to address the variation in consumption of food amongst individuals, and account for actual body weights providing a more accurate representation of the 'true' exposure. The migrants bisphenol A diglycidyl ether (BADGE), di-2-ethylhexyl adipate (DEHA) and styrene were considered as specimen compounds although the methodology employed has the flexibility to adapt to other migrants and packaging types and indeed other food contaminants. Exposure for each individual is estimated by calculating and summing the individual exposure from each item in their diet, and is repeated for all individuals in each survey to produce a distribution of exposures for the population. The packaging type of each food item is assigned by utilizing known packaging types from the database or, by sampling from a distribution based upon market share information. The parameters contributing towards the exposure from a packaged dietary item are migrant concentration and item weight. Distributions are used to represent the inherent variation and uncertainty affecting these parameters. Where data on concentrations for a particular type of food are lacking, expert judgement is used to extrapolate from available data for other food types. The model can also be run using only migration data for food simulants. In this case, concentrations expected for each of the food items are assigned based on the data for the relevant food simulant. The primary outputs of the model are distributions of estimated daily intakes for the selected population. Each distribution gives the variation across the population subject to the uncertain parameters sampled in that iteration of the model. Analysing the ensemble of distributions allows us to obtain the confidence limits around estimates for percentiles due to the uncertainties. The probabilistic approach allows sensitivity analysis to evaluate the relative importance of the input parameters and places confidence bounds on the outputs to show the effect of the uncertainties and the contribution of each food type toward the overall exposure.     

Consumer exposure to phthalates from paper packaging: an integrated approach

This paper presents an integrated approach to estimate the exposure of the Portuguese population to phthalates as a contaminant originating from paperboard packaging. The approach combined data of migrant concentration in the foods resulting from a stochastic simulation with consumption data of food packaged in paperboard. The results from the exposure model were validated with experimental values actually found in the food. A short surveillance exercise was conducted with samples collection from market shelves to identify and quantify the phthalates present in both the packages and the food. The distribution of values for the di-butyl phthalate concentration in the packages was used as the input of the initial concentration in the Weibull model to estimate the concentration of this phthalate in the foods. This distribution of occurrence data was then combined with the packaging usage data in a probabilistic simulation with a Monte Carlo sampling method. Exposure values ranged between zero and 8.95 µg day^?1 kg_bw, a value close to the tolerable daily intake established by the European Food Safety Authority (EFSA)–10 µg day^?1 kg_bw. However, the 97.5th percentile and the average were 1.82 and 0.44 day^?1 kg_bw, respectively, indicating that further refinement of the estimates is not necessary. Other phthalates were also detected in the packaging samples: di-isobutyl phthalate and di-ethylhexyl phthalate. The latter was present in all packaging samples collected and was detected in a few food samples at values requiring further investigation.     

Use and impact of usual intake models on dietary exposure estimate and risk assessment of chemical substances: a practical example for cadmium,acrylamide and sulphites

To estimate of food and nutrient intakes, 24-h recalls are frequently used in dietary assessment. However intake data collected for a short period are a limited estimator of long-term usual intake. An important limitation of such data is that the within-person variability tends to inflate the intake distribution leading to a biased estimation of extreme percentiles. Statistical models, named usual-intake models, that separate the within-person variability from the between-persons variability, have lately been implemented. The main objectives of this study were to highlight the potential impact that usual-intake models can have on exposure estimate and risk assessment and to point out which are the key aspects to be considered in order to run these models properly and be sure to interpret the output correctly. To achieve the goal we used the consumption data obtained by the French dietary survey INCA2 and the concentration data collected during the French TDS2, using Monte Carlo Risk Assessment (MCRA) software, release 8.0. For the three substances included in this study (cadmium, acrylamide and sulphites), the exposure of the upper percentiles was significantly reduced when using usual-intake models in comparison with the results obtained in the observed individual mean models, even if in terms of risk assessment the impact of using usual-intake models was limited. From the results it appears that the key aspects to consider when using usual-intake models are: (1) the normality of the log-transformed intake distribution, (2) the contribution per single food group to the total exposure, and (3) the independency of food consumption data on multiple days. In conclusion, usual-intake models may have an impact on exposure estimates although, referring to the results, it did not bring any changes in terms of risk assessment, but further investigations are needed.     

Sulfite content in some Brazilian wines: analytical determination and estimate of dietary exposure

Brazilian wines of different regions and that commercially available in the city of Campinas, SP, were analysed for their contents of sulfites. Dietary exposure to sulfites from Brazilian wines was also assessed by combining sulfite levels determined analytically with three hypothetical scenarios of daily wine consumption: 150, 300, and 450 mL. In all samples, the concentration of sulfites was below the maximum permitted level (MPL) of 350 mg L⁻¹ set in the Brazilian legislation with most samples (88%) containing residual sulfite below 150 mg L⁻¹. The dietary exposure to sulfites from regular consumption of 150 mL of national white wines containing sulfites at the mean level of 122.0 mg L⁻¹ covered 44% of the Acceptable Daily Intake (ADI) established by JECFA for these preservatives (0.7 mg kg⁻¹ bw). For high regular consumption (450 mL per day) of white wines, the dietary exposure could reach 131% of the ADI. In the case of national red wines (SO₂ mean level of 71.3 mg L⁻¹) the dietary exposure was lower, ranging from 26 to 76% of the ADI for 150 and 450 mL of daily consumption, respectively. The present study indicates that although sulfite levels in national wines is usually below the MPL (mean of 98.5 mg L⁻¹) a regular moderate consumption of 150 mL per day could lead to a dietary exposure of 15 mg of sulfites (0.25 mg kg⁻¹ bw in a 60-kg adult), covering one-third of the ADI. A regular heavy consumption (450 mL per day) would cover the full ADI.     

Estimates of dietary exposure to bisphenol A (BPA) from light metal packaging using food consumption and packaging usage data: a refined deterministic approach and a fully probabilistic (FACET) approach

The FACET tool is a probabilistic model to estimate exposure to chemicals in foodstuffs, originating from flavours, additives and food contact materials. This paper demonstrates the use of the FACET tool to estimate exposure to BPA (bisphenol A) from light metal packaging. For exposure to migrants from food packaging, FACET uses industry-supplied data on the occurrence of substances in the packaging, their concentrations and construction of the packaging, which were combined with data from a market research organisation and food consumption data supplied by national database managers. To illustrate the principles, UK packaging data were used together with consumption data from the UK National Diet and Nutrition Survey (NDNS) dietary survey for 19–64 year olds for a refined deterministic verification. The UK data were chosen mainly because the consumption surveys are detailed, data for UK packaging at a detailed level were available and, arguably, the UK population is composed of high consumers of packaged foodstuffs. Exposures were run for each food category that could give rise to BPA from light metal packaging. Consumer loyalty to a particular type of packaging, commonly referred to as packaging loyalty, was set. The BPA extraction levels used for the 15 types of coating chemistries that could release BPA were in the range of 0.00005–0.012 mg dm^–2. The estimates of exposure to BPA using FACET for the total diet were 0.0098 (mean) and 0.0466 (97.5th percentile) mg/person/day, corresponding to 0.00013 (mean) and 0.00059 (97.5th percentile) mg kg^–1 body weight day^–1 for consumers of foods packed in light metal packaging. This is well below the current EFSA (and other recognised bodies) TDI of 0.05 mg kg^–1 body weight day^–1. These probabilistic estimates were compared with estimates using a refined deterministic approach drawing on the same input data. The results from FACET for the mean, 95th and 97.5th percentile exposures to BPA lay between the lowest and the highest estimates from the refined deterministic calculations. Since this should be the case, for a fully probabilistic compared with a deterministic approach, it is concluded that the FACET tool has been verified in this example. A recent EFSA draft opinion on exposure to BPA from different sources showed that canned foods were a major contributor and compared results from various models, including those from FACET. The results from FACET were overall conservative.     

中国地区干酪生物胺风险评估中膳食暴露评估模型的构建

基于对中国地区市售97份干酪样品获得的8种生物胺检测数据,以及2002年中国居民营养与健康状况调查报告中的膳食消费数据,采用Monte Carlo模拟和@Risk软件量化人群干酪生物胺膳食暴露量的变异度和不确定度,构建中国地区干酪生物胺风险评估中膳食暴露评估模型。按不同地区、性别和年龄段差异的人群,分析其干酪生物胺膳食暴露量分布的统计量和90%置信区间。评估结果显示,中国城市人群的干酪生物胺暴露量明显高于同年龄段的农村人群;且城市地区女性暴露量通常高于男性,而农村地区则相反。干酪生物胺膳食暴露概率评估方法相比点评估和简单分布评估方法,能够定量评估结果的变异度和不确定度,评估更为准确。      

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.     

Estimation of exposure to food packaging materials. 3: Development of consumption factors and food-type distribution factors from data collected on Irish children

There are many initiatives in Europe trying to refine the exposure assessment for food packaging migrants. In the USA, the US Food and Drug Administration (US FDA) uses food consumption and food-type distribution factors to aid the exposure assessment process and generate more realistic estimates of exposure. The present study developed food-consumption factors and food-type distribution factors for Irish children aged 5-12 years from data collected as part of a National Children's Food Survey (NCFS) completed in Ireland in 2003-04, combined with data from the 2003-05 Irish Food Packaging Database and from literature data on surface area-to-weight ratios for food packaging. Consumption factors are defined as the fraction of a person's diet likely to contact a specific food-contact material, while food-type distribution factors reflect the fraction of all food contacting each material that is aqueous, acidic, alcoholic or fatty. In this study, it was found that 'total plastics' had the highest consumption factor of 0.83, while 'total paper and board' had a factor of 0.13 and 'total metal and alloys' had a factor of 0.06. Although it is tentative to compare the US FDA factors with the factors derived in the current study, as the US FDA data are for the total US population, the consumption factor for 'total plastics' in the present study (0.83) was similar to that used by the US FDA (0.79). However, a large difference existed for the consumption factor for 'total metal and alloys' in the Irish data (0.06) and the US FDA data (0.2). In terms of the type of materials used for foods, glass was used mainly for acidic foods (0.67), while plastic was uniformly used for all food types. The food-contact area for plastic packaging for all foods consumed by children was 10.67 dm²/child day^-1, which is slightly lower than the proposed value for the average European consumer of 12.4 dm²/person day^-1. However, this should be expected, as children do not consume as much food as adults. When scenario exposure estimates were made, it was found that when using European Union assumptions, estimates were much larger than when using consumption factors and food-type distribution factors in the exposure assessment, even when conservative assumptions were employed for the consumption factor. This study highlights the potential use of consumption factors and food-type distribution factors in the refinement of the exposure assessment process and how these factors can be calculated using data collected as part of a national food survey.     

欧美和日本等国食品包装材料膳食暴露评估方法的比较分析

本文介绍了美国、欧盟、日本和加拿大在开展食品包装材料暴露评估时采用方法的原理、所需资料和计算过程,并对各种方法的覆盖面、实用性、难易程度等方面进行了比较,分析各自优缺点,为建立适合于我国国情的食品包装材料暴露评估方法,制修订食品包装材料安全标准提供科学依据,同时为食品包装材料风险评估机构、监管部门以及相关行业、企业开展相关研究工作提供参考.     

Evaluating daily exposure to polychlorinated biphenyls and polybrominated diphenyl ethers in fish oil supplements

Fish oil supplements have become a popular means of increasing one's dietary intake of essential polyunsaturated fatty acids. However, there is growing concern that the levels and potential health effects of lipophilic organic contaminants such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) may diminish some of the health benefits associated with the daily consumption of fish oil supplements. In this study, ten over-the-counter fish oil supplements available in the United States were analysed for PCBs and PBDEs and daily exposures calculated. Based on manufacturers’ recommended dosages, daily intakes of PCBs and PBDEs ranged from 5 to 686 ng day^?1 and from 1 to 13 ng day^?1, respectively. Daily consumption of fish oil supplements expose consumers to PCBs and PBDEs. However, in comparison with fish ingestion, fish supplements may decrease daily PCB exposure and provide a safer pathway for individuals seeking to maintain daily recommended levels of polyunsaturated fatty acids.     

Semicarbazide – from state-of-the-art analytical methods and exposure to toxicity: a review

This review assesses the state of the art concerning semicarbazide (SEM). Originally, SEM was primarily detected as a nitrofurazone veterinary metabolite, but over time scientists gradually found that azodicarbonamide in sealed cans and flour could also lead to the generation of SEM. This discovery makes the study of SEM particularly interesting. At present, an increasing number of researchers are investigating the toxicity of SEM and developing more and better analytical methods for the determination of SEM. In recent years, many researchers have focused on exposure from different foods, the public awareness of hazards and analytical detection methods for SEM in different foods. Although there have been significant achievements, these results have not been summarised in a review. The exposure from different foods, toxicity and methods of detection for SEM are comprehensively reviewed here. This review will provide not only others with a better understanding of SEM but also background information to facilitate future research.     

Migration of styrene monomer, dimers and trimers from polystyrene to food simulants

Migration experiments with polystyrene were performed in two-sided contact with n-heptane and distilled water as the food simulants at temperatures of 10, 24 and 40, and 40, 60 and 90°C, respectively. The surface/volume ratios in the migration cell were set at 8.04 and 10.05 dm² l^-1 for n-heptane and distilled water, respectively. Styrene monomer, styrene dimers and styrene trimers migrating to the food simulants were determined by GC-FID analysis. Heptane fully extracted the styrene monomer and the oligomers from the polystyrene sheet, whereas in the distilled water only the migrated styrene trimers could be detected. To determine the apparent diffusion coefficient, the migration process was analysed based on Fick's law. The higher the molecular weight of the oligomers, the more significant the reduction in the diffusion coefficient. Higher molecular weight oligomers also had lower activation energy of diffusion when the temperature dependence of diffusivity was analysed by the Arrhenius equation. The diffusion coefficient of the trimers was much higher for heptane contact than for water. The activation energy of the diffusion of trimers for water contact was higher than that for heptane.     

Application of triacylglycerol and fatty acid analyses to discriminate blended sesame oil with soybean oil

Triacylglycerols (TAGs) and fatty acids in the mixture of sesame oil (SO) with soybean oil were analysed using high performance liquid chromatography (HPLC)–an evaporative light scattering detector (ELSD) and gas chromatography (GC)–a flame ionisation detector (FID). Relative percentage of linolenic acid increased rapidly compared to those of oleic and linoleic acids as the ratio of soybean oil increased in the blended SO. Peak responses of trilinolein (LLL) and trilinolenin (LnLnLn) by HPLC–ELSD was higher than those by GC–FID from the same concentration of TAGs. The presence of LLLn peak, the contents of linolenic acid, and the relative ratio of L/S, O/Ln, and L/Ln from fatty acids or LLL/OOO from TAGs could be useful indicators to detect the blended SO with soybean oil. TAG analysis by HPLC–ELSD coupled with fatty acids by GC–FID can be useful methods to discriminate blended SO with soybean oil.     

Assessment of uncertainty in a probabilistic model of consumer exposure to pesticide residues in food

The assessment of consumer exposure to pesticides is an important part of pesticide regulation. Probabilistic modelling allows analysis of uncertainty and variability in risk assessments. The output of any assessment will be influenced by the characteristics and uncertainty of the inputs, model structure and assumptions. While the use of probabilistic models is well established in the United States, in Europe problems of low acceptance, sparse data and lack of guidelines are slowing the development. The analyses in the current paper focused on the dietary pathway and the exposure of UK toddlers. Three single food, single pesticide case studies were used to parameterize a simple probabilistic model built in Crystal Ball™. Data on dietary consumption patterns were extracted from National Diet and Nutrition Surveys, and levels of pesticide active ingredients in foods were collected from Pesticide Residues Committee monitoring. The effect of uncertainty on the exposure estimate was analysed using scenarios, reflecting different assumptions related to sources of uncertainty. The most influential uncertainty issue was the distribution type used to represent input variables. Other sources that most affected model output were non-detects, unit-to-unit variability and processing. Specifying correlation between variables was found to have little effect on exposure estimates. The findings have important implications for how probabilistic modelling should be conducted, communicated and used by policy and decision makers as part of consumer risk assessment of pesticides.