Influence of processing factors on the estimation of consumer exposure to pesticide residues

Estimation of consumer exposure to chemicals: application of simple models

Probabilistic techniques were used to characterize dietary exposure of consumers to pesticides found in twelve commodities implicated as having the greatest potential for pesticide residue contamination by a United States-based environmental advocacy group. Estimates of exposures were derived for the ten most frequently detected pesticide residues on each of the twelve commodities based upon residue findings from the United States Department of Agriculture's Pesticide Data Program. All pesticide exposure estimates were well below established chronic reference doses (RfDs). Only one of the 120 exposure estimates exceeded 1% of the RfD (methamidophos on bell peppers at 2% of the RfD), and only seven exposure estimates (5.8 percent) exceeded 0.1% of the RfD. Three quarters of the pesticide/commodity combinations demonstrated exposure estimates below 0.01% of the RfD (corresponding to exposures one million times below chronic No Observable Adverse Effect Levels from animal toxicology studies), and 40.8% had exposure estimates below 0.001% of the RfD. It is concluded that (1) exposures to the most commonly detected pesticides on the twelve commodities pose negligible risks to consumers, (2) substitution of organic forms of the twelve commodities for conventional forms does not result in any appreciable reduction of consumer risks, and (3) the methodology used by the environmental advocacy group to rank commodities with respect to pesticide risks lacks scientific credibility.

Consumers come into contact with chemical substances by using cleaning products. Accurate estimation of human exposure is a necessity in assessing the potential risks of chemical substances in consumer products. The Cleaning Products Fact Sheet that supports in estimating such exposure has been recently revised. New data collected from literature and re-interpretation of existing data has led to the adjustment of a number of default values used for exposure calculations. For some cleaning products (such as all-purpose cleaner spray and bathroom cleaner spray) increased exposure values are calculated, whereas for other products (such as liquid laundry detergent and liquid floor cleaner) the calculated exposure value seems to decrease. This is shown by RIVM research in which the impact of new data on estimated human exposure to substances in cleaning products has been investigated. Consumer exposure estimates based on the content of the Cleaning Products Fact Sheet of 2006 were compared to those based on the updated content in 2018. The impact was evaluated and found to depend on the way the product is used, its substance ingredients, and whether the exposure is via dermal contact or inhalation of substances. The Cleaning Products Fact Sheet was developed to support the users of ConsExpo, a computer model developed by RIVM for calculating human exposure to substances in consumer products. This fact sheet describes the default models to use and the default values to insert in order to perform a standardised and transparent consumer exposure estimation for substances in cleaning products

TS1-13 Abstract: Canada is the first country to introduce a legislative requirement for systematic priority setting for all existing chemicals. In addition to a continuing mandate to establish and conduct full assessments for lists of priority substances, the Canadian Environmental Protection Act (CEPA '99) requires that the Ministers of Health and Environment complete “categorization” (priority setting) of all of the approximately 23,000 substances on the Domestic Substances List (DSL) by September 2006, with subsequent screening and full risk assessment, when warranted. These requirements set the stage for identification of highest priority substances for subsequent introduction of control measures to reduce exposure in both consumer products and the general environment. This precedent setting mandate has required the development and refinement of methodology for priority setting and risk assessment for a wide range of diverse substances. These approaches draw maximally from available, often generic information as a basis to consider large numbers of substances, for which individual data on exposure and hazard are often limited. Estimation of exposure to consumer products is addressed both in priority setting and assessment stages of the program. For consumer products, an approach has been developed to provide quantitative estimates of exposure relevant in a priority setting context. This has required consideration of the relative degree of conservatism in existing exposure modeling algorithms and development of a considerable number of additional scenarios and leads to quantitative plausible maximum estimates of exposure of individuals in the general population by age group based on use scenario, physical/chemical properties, and bioavailability. Comparison of the output with measures of exposure–response for relevant critical effects leads to substances being set aside from further consideration or prioritized for additional assessment. After 2006, the approach will also contribute to efficient screening, delineating the focus of subsequent assessment. The development and integration of consumer exposure modeling in increasingly broad legislative mandates to systematically consider all existing chemicals raises a number of issues relevant to exposure assessment in differing jurisdictions. These include transparency, consistency, usability, and defensibility of the models, including relevant degree of complexity for priority setting versus assessment. These issues are discussed through examples and lessons learned from the development of the approach to consumer products for priority setting and screening assessment.

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.

This Opinion describes recent developments in the safety assessment of chemicals in food and explores their potential impact on EFSA evaluation of food contact materials (FCM). It is not intended to be a guidance document. The draft opinion was subject to a public consultation and this final Opinion takes into account the scientific comments received. The Opinion will provide the European Commission with the scientific basis for a discussion among risk managers on possible implications for risk management. One major area to revisit is the estimation of consumer exposure. Four food consumption categories could be set. They are approximately 9, 5, 3 and 1.2 times higher than the current SCF default scenario, i.e. 17 g/kg bw per day, and so using them would afford a higher level of protection, particularly for infants and toddlers. Special exposure scenarios might be used if consumption were lower. The amount of toxicity data needed should be related to the expected human exposure. The tiered approach of the SCF is updated. For substances used in FCM, genotoxicity testing is always required, even if their migration leads to a low exposure. Beyond this, three threshold levels of human exposure, namely 1.5, 30 and 80 μg/kg bw per day, are proposed as triggers for the requirement for additional toxicity data. Regarding the identification and evaluation of migrating substances, experience has shown that more focus is needed on the finished materials and articles. Considering the non-intentionally added substances (NIAS), such as impurities of the substance along with reaction and degradation products including oligomers, the same approach as is used for authorised substances could, in principle, be applied for their toxicological assessment, as the same degree of safety should be warranted for all migrating substances. However, non-testing methods could have increased importance for the assessment of genotoxicity of NIAS.

Discussions as to the extent of pesticide residue contamination in the food supply often rely on results of government residue monitoring programs focusing primarily upon the percentages of samples containing pesticide residues and the number of violative residues identified. Such an approach does not adequately convey the likelihood of pesticide residues posing consumer risks since residue regulatory limits are not safety standards and violative pesticide residues rarely constitute residues of health concern. It is more appropriate to develop estimates of actual dietary exposure to pesticides and to compare such estimates to established toxicological criteria such as the Chronic Reference Dose (RfD). The U.S. Food and Drug Administration's (FDA) Total Diet Study (TDS) previously provided such information but last published its findings in 1995 to estimate dietary exposure to pesticides detected between 1986 and 1991. This paper provides updated estimates of dietary exposure to pesticides in the United States using the most recent TDS findings on pesticide residues. A total of 77 specific pesticides were detected from market basket samples of 2240 TDS food items analyzed by FDA in 2004 and 2005. All estimated exposures to the 77 pesticides for the General US population were well below chronic RfD levels. Only 3 of the 77 pesticides showed exposures greater than 1 % of chronic RfDs, while 14 showed exposures between 0.1 and 1 % of chronic RfDs and 19 had exposures between 0.01 and 0.1 % of chronic RfDs. The remaining 41 pesticides had exposures below 0.01 % of chronic RfDs. Compared with 1986–1991 findings, dietary exposure to six environmentally persistent chlorinated hydrocarbon insecticides were reduced by factors of 47 to 96 % in 2004–2005. Exposures to 15 different population subgroups were estimated and indicated that children, particularly two year-olds, frequently receive higher exposures to pesticide residues in their diets than do adults. Chronic dietary exposure to pesticides in the diet, according to results of the FDA's 2004–2005 TDS, continue to be at levels far below those of health concern. Consumers should be encouraged to eat fruits, vegetables, and grains and should not fear the low levels of pesticide residues found in such foods.

BackgroundVinyl acetate monomer (VAM) (CAS 108-05-4) is employed in the creation of an array of polymers and copolymers used in the manufacture of consumer products. There is no direct use of VAM in consumer products. However, residual amounts of unreacted VAM in (co)polymer products have been identified as a possible general population exposure concern.ObjectiveThe objective of this evaluation was to provide a contemporary review of exposure to VAM via residual VAM (co)polymer in a range of consumer products in the United States.MethodsThe study authors conducted a market-basket sampling of residual VAM levels in 71 consumer products purchased in the United States that met the selection criteria. Subsequently, exposure assessments were conducted using ConsExpo (version 1.1.1) and the United States Environmental Protection Agency’s Consumer Exposure Model (CEM; version 2.1) on a subset of those identified products.ResultsOf the products analyzed, 40 had VAM concentrations below the lowest detection limits (0.1–2 ppmw), 19 were non-detectable but the product materials demonstrated atypical or nonlinear calibration behavior, four had detectable VAM in the 2–10 ppmw range, and eight had detectable VAM from 10 to 648 ppmw. Eleven use scenarios were developed based on seven categories of consumer products from the evaluation. Resulting exposure estimates were all less than both acute and chronic non-cancer human health thresholds.ImpactThis study presents an analytical detection methodology for residual VAM present in a variety of consumer products. The information presented herein can inform future studies of VAM exposure and facilitate exposure estimates of VAM in similar products by providing measured concentrations. This study also demonstrates that, for the products evaluated, potential VAM exposure is less than acute and chronic health thresholds for the general public based on modeled exposure estimates.

Estimation of smokers' exposure to mercury from combustible tobacco products, based on the approach used in food consumers’ exposure estimation

Since the discovery of acrylamide in foods, there have been many calculations of dietary exposure. Total diet studies have been commonly used to estimate consumer exposure of acrylamide; however, these often fall short in evaluating true exposure levels because of limitations in small occurrence data sets. Dietary exposure to acrylamide can also be estimated by use of modeling packages. The U.K. Food Standards Agency and the Food Safety Authority of Ireland have prepared estimates for dietary acrylamide exposure using semiprobabilistic and probabilistic modeling. Occurrence data were obtained from the European Union acrylamide monitoring database, whereas consumption data were obtained from the relevant U.K. and Irish National Diet and Nutrition Surveys. The mean adult U.K. consumer exposure was estimated as 0.61 microg/kg of body weight (bw)/day and high-level adult consumer exposure (P97.5) as 1.29 microg/kg of bw/day. The mean adult Irish consumer exposure was estimated as 0.59 microg/kg of bw/day and the high-level adult consumer exposure (P97.5) as 1.75 microg/kg of bw/day. Owing to the wide range of acrylamide levels in foods, semiprobabilistic modeling does not always provide an accurate picture of dietary exposure levels and patterns. Therefore, a comparison of semiprobabilistic assessments to probabilistic assessments of U.K. and Irish dietary exposure estimates of certain food groups is provided.

Risk Assessment: Chemical Hazards

β-Casomorphin-7 (BCM-7), a heptapeptide derived from β-casein hydrolysis, has gained attention for its potential role in gastrointestinal discomfort and certain diseases, yet its effects remain controversial. This study aimed to provide the first reliable estimation of BCM-7 exposure for low, medium and high consumers of milk and dairy products in the European population. We developed a database on BCM-7 released after simulated digestion, combining literature review and direct analysis of milk and selected dairy products. Using European food consumption data, we estimated BCM-7 daily exposure for adults (132–2541 μg), adolescents (163–2594 μg) and children (200–2357 μg). Milk emerged as the most significant source of BCM-7 exposure across all population groups. Statistical analysis revealed differences in exposure levels between adults and children at medium consumption levels. This work provides the first comprehensive estimation of dietary BCM-7 exposure, laying the groundwork for future research on its potential health effects.

Use of an aggregate exposure model to estimate consumer exposure to fragrance ingredients in personal care and cosmetic products

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

Next generation risk assessment is defined as a knowledge-driven system that allows for cost-efficient assessment of human health risk related to chemical exposure, without animal experimentation. One of the key features of next generation risk assessment is to facilitate prioritization of chemical substances that need a more extensive toxicological evaluation, in order to address the need to assess an increasing number of substances. In this case study focusing on chemicals in food, we explored how exposure data combined with the Threshold of Toxicological Concern (TTC) concept could be used to prioritize chemicals, both for existing substances and new substances entering the market. Using a database of existing chemicals relevant for dietary exposure we calculated exposure estimates, followed by application of the TTC concept to identify substances of higher concern. Subsequently, a selected set of these priority substances was screened for toxicological potential using high-throughput screening (HTS) approaches. Remarkably, this approach resulted in alerts for a selection of substances that are already on the market and represent relevant exposure in consumers. Taken together, the case study provides proof-of-principle for the approach taken to identify substances of concern, and this approach can therefore be considered a supportive element to a next generation risk assessment strategy.