Acute Dietary Risk Research Articles

Dietary cumulative acute risk assessment of organophosphorus, carbamates and pyrethroids insecticides for the Brazilian population

Cumulative acute dietary risk assessments of organophosphorus (OPs), carbamates (CBs) and pyrethroids (PYs) were conducted for the Brazilian population. Residue data for 30786 samples of 30 foods were obtained from two national monitoring programs and one University laboratory, and consumption data from a national survey conducted among persons 10 years or older. Acephate and methamidophos were used as index compounds (IC) for OPs, oxamyl for CBs and deltamethrin for PYs. Exposures were estimated using the Monte Carlo Risk Assessment (MCRA 8.2) software. Orange and orange juice (mainly containing methidathion), pasta and salted bread (mainly pirimiphos-methyl) contributed most to the OPs intake. Rice accounted for 80% of the CBs intake (teenagers), mainly due to aldicarb. Pasta, salted bread and beans contributed most to the PYs intake (9–14%), mainly due to bifenthrin. The intake did not exceed the ARfD at the 99.9th percentile for OPs, CBs and PYs, and the risks from the exposure were not considered of health concern. When food consumption data become available for children under age 10, studies in the cumulative exposure should be conducted, as this age group is the most critical among the population, mainly due to their higher food consumption per kg body weight.

Acute dietary risk assessment for the fungicide carbendazim in fruits and vegetables consumed in Brazil

Acute dietary risk assessment for the fungicide carbendazim in fruits and vegetables consumed in Brazil

Risk assessment of pesticide residues in dietary intake of celery in China

ObjectiveResidue risk assessment of pesticides in celery was conducted to provide a scientific basis for agricultural regulation policies and working procedures. MethodsThree hundred samples from eight main growing regions in China were collected and pesticide residue analyses were performed using GC–MS/MS and LC-MS/MS methods. Both chronic and acute intake risk of pesticides were assessed. Furthermore, intake risk of each detected pesticide was ranked according to a predefined ranking matrix. Results(1) Out of these 300 samples, 175 were revealed to contain one or more pesticide residues. Twenty-five pesticides were identified in total, out of which, carbofuran was found to exceed the maximum residue limit. (2) Chronic and acute intake risks were evaluated and lie in between 0 and 1.80 and between 0.05 and 28.0 for these twenty-five pesticides, respectively. (3) Intake risk of individual pesticide was ranked; five pesticides, including avermectin, triazophos, chlorpyrifos, dimethoate oxygen, and carbofuran posed the highest risks. ConclusionPesticide residues were detected in more than 58% celery samples in our study. Most pesticides have a residue level lower than their maximum residue limit and pose low chronic and acute dietary intake risk. However, usage of some pesticides like carbofuran should be closely monitored and regulated in the future.

Pesticide residues and acute dietary risk assessment in Polish raw food (2005–2013)

Pesticide residues and acute dietary risk assessment in Polish raw food (2005–2013)

How dietary risk assessment can guide risk management and food monitoring programmes: The approach and results of the French Observatory on Pesticide Residues (ANSES/ORP)

The French system for monitoring dietary exposure to pesticide residues and its scoring method are presented. This system aims both to assess acute and chronic risks to the general population and to identify food commodities and pesticides that need to be better monitored and/or regulated thanks to 6 priority levels. The method combines four chronic and acute dietary risk indicators based on the results of the most recent national monitoring programmes and maximum residue levels, in connection with individual and national food consumption data. The probability of exceeding the toxicological reference values was estimated for children and adults, for 522 pesticides and their metabolites. Food contributors were detailed and a minimum number of samples to be taken per food was proposed. The majority of the pesticides (87%) was scored at the lowest priority level 1. For pesticides classified in levels 2 to 5, there is a need to refine the assessment. The monitoring should also be extended to include newly authorised substances in levels 2 to 4. Carbendazim, dimethoate, dithiocarbamates and imazalil merit particular attention as they scored at level 6 and are frequently quantified in fruits and vegetables, meaning that risk managers should take corrective measures in order to ensure consumer safety.

Scientific Opinion on Evaluation of the Toxicological Relevance of Pesticide Metabolites for Dietary Risk Assessment

The European Food Safety Authority (EFSA) asked the Panel on Plant Protection Products and their Residues (PPR) to develop an opinion on approaches to evaluate the toxicological relevance of metabolites and degradates of pesticide active substances in dietary risk assessment. This opinion identifies the threshold of toxicological concern (TTC) concept as an appropriate screening tool. The TTC values for genotoxic and toxic compounds were found to be sufficiently conservative for chronic exposure, as a result of a validation study with a group of pesticides belonging to different chemical classes. Three critical steps were identified in the application of a TTC scheme: 1) the estimate of the level of the metabolite, 2) the evaluation of genotoxicity alerts and 3) the detection of neurotoxic metabolites. Tentative TTC values for acute exposure were established by the PPR Panel by analysis of the lowest 5th percentiles of No Observed Adverse Effect Levels (NOAELs) used to establish the Acute Reference Doses (ARfD) for the EFSA pesticide data set. Assessment schemes for chronic and acute dietary risk assessment of pesticide metabolites, using the TTC approach and combined (Q)SAR and read across, are proposed. The opinion also proposes how the risk assessment of pesticide metabolites that are stereoisomers should be addressed due to isomer ratio changes reflected in the composition of metabolites. The approach is ready for use, but it is anticipated that on many occasions the outcome of the assessment scheme will be that further testing is needed to reach a firm conclusion on the toxicological relevance of the metabolite. However, the benefit of applying the approach is that it will allow prioritisation of metabolites for subsequent testing. EFSA will develop a Guidance Document based on the results in this opinion.

Bats at risk? Bat activity and insecticide residue analysis of food items in an apple orchard

Although bats are reported as being threatened by pesticides, they are currently not considered in European Union pesticide risk assessments. The reason for that contradiction is probably related to the scarcity of information on bat activity in pesticide-treated fields and the pesticide residues on their food items. The authors recorded bat activity and measured pesticide residues on bat-specific food items following applications of two insecticides in an apple orchard. High activity levels of the common pipistrelle bat, a foraging habitat generalist, were detected. Airborne foragers and bats that take part of their food by gleaning arthropods from the vegetation were recorded frequently. The initial value and the decline of pesticide residues were found to depend on the arthropod type, their surface to volume ratio, their mobility, and the mode of action of the applied pesticide. The highest initial residue values were measured on foliage-dwelling arthropods. By following the toxicity-exposure ratio approaches of the current pesticide risk assessment, no acute dietary risk was found for all recorded bat species. However, a potential reproductive risk for bat species that include foliage-dwelling arthropods in their diet was indicated. The results emphasize the importance of adequately evaluating the risks of pesticides to bats, which, compared to other mammals, are potentially more sensitive due to their ecological traits.

Degradation of Chlorpyrifos and Fipronil in Rice from Farm to Fork and Risk Assessment

Degradation of pesticide residues (chlorpyrifos and fipronil) in rice from farm to fork and risk assessment for human health were studied to reveal the magnitude of risks faced by different populations of interest, so that appropriate measures can be taken to control the risks, and to refine and update the human health risk assessment data while helping to determine the maximum residue level (MRL) value and harvest interval. Different dosages and treatments were used in field trials for the harvest residue test. Residue levels of postharvest-applied chlorpyrifos and fipronil during storage, exposure to sunlight, washing and boiling processes (boiled rice) were investigated for brown rice. The dietary exposure evaluation model (DEEM) was employed to estimate acute and chronic risks faced by different populations of interest. Percent of reference dose (POR) and margin of exposure (MOE) were calculated. A positive correlation between pesticide residues and the dosage and application frequency of pesticide was found in the field trials. Risk quotients indicate that multiple applications and double dosages of chlorpyrifos increase the risks to the entire population and prolong exposures to toxic concentrations. The concentration of pesticide residues decreased as a function of time, after sunlight exposure, storage, washing, and boiling processes. 91.6 and 96.16% degradations were achieved at the end of the experimental period for fipronil and chlorpyrifos, respectively. The boiling process played an important role in the degradation of these pesticides. The result of risk assessment to human health showed that harvest residues of chlorpyrifos in rice and acute dietary risks of chlopyrifos were of concern. The acute dietary (food only) risk estimated for chlorpyrifos as percent of acute population adjusted dose (aPAD) was frequently over 100%. The risk faced by boys under the age of 14 was higher than that for girls of the same age. For the subpopulation above age 14, the risk reversed. The chronic dietary risk from food alone showed that dietary exposures with fipronil were below the level of concern for the entire population, including children. The risk faced by rural residents was more serious than that for urbanite residents with the most sensitive populations being children and male residents who faced higher acute dietary risk than the other subpopulation groups. The harvest interval was found to be the critical measure to mitigate risk for all populations for safe rice eating. All risk levels decreased to acceptable levels when the harvest interval was extended to 14 d. To address these risks, a number of measures including reduced application rates (should not be doubled at single application), increased retreatment intervals (longer than 7 d) and extended interval of harvest (at least 14 d) will be needed. The MRL for fipronil in rice is recommended to be 0.01 mg kg −1 in accordance with Codex (ref).

Organophosphorus pesticide residues in Greek virgin olive oil: levels, dietary intake and risk assessment

The occurrence of organophosphorus pesticide (OPs) and their metabolite residues was investigated in 167 samples of Greek virgin olive oil during a 2-year (2004–2005) sampling campaign. A total of 30.5% of samples contained detectable residues, although only one sample contained dimethoate residues above the maximum residue limit. Among the seven detected OPs, fenthion and fenthion sulfoxide residues were detected in 10.8 and 14.4% of the samples, respectively, at levels of 0.003–0.61 mg kg−1. Dimethoate was detected in 10.2% of the samples at 0.003–0.057 mg kg−1. The acute dietary risk assessment was undertaken by determining the national estimated short-term intake (NESTI); for chronic dietary risk assessment, the national theoretical maximum daily intake (NTMDI) and national estimated daily intake (NEDI) were calculated. The estimated intakes (NESTI and NEDI) of each pesticide were <7 and <0.86% of the corresponding acute reference doses (ARfDs) and acceptable daily intakes (ADIs), respectively. A cumulative risk assessment was performed using the hazard index (HI) and toxicity equivalence factor (TEF), taking into account that OPs share the same toxicological mechanism. The determined HI and TEF values were found to represent only a small portion of the respective ADIs or ARfDs. These results indicate that there is neither acute nor chronic risk for the Greek population through olive oil consumption.

Continuing Advances in Acute Dietary Risk Assessment for Agrochemicals

Continuing Advances in Acute Dietary Risk Assessment for Agrochemicals

Refinements in acute dietary exposure assessments for chlorpyrifos.

Food pesticide residue data are used by the U.S. Environmental Protection Agency (EPA) to determine potential dietary risk from chronic and acute exposures. An acute dietary risk assessment determines the pesticide exposure resulting from a single-day consumption of food, and uses stepwise refinement of residue estimates to better judge actual exposures. All exposure refinements use estimates of the fraction of crops treated and food residues measured increasingly closer to the point of actual food consumption, without changes in the pesticide uses. Exposure distributions at all levels of data refinement were extremely right skewed. At the highest level evaluated, estimated exposures at the 99.9th percentile were 0.00087 mg/kgBW/day compared to 0.2648 mg/kgBW/day at the tolerance level for children 1-6 years, theoretically the highest-exposed population sub-group. The estimated exposure at the 99.9th percentile of the U.S. population was approximately twice the exposure at the 99th percentile and 33 times the exposure at the 90th percentile. This evaluation showed the calculated exposure at the highest tier of assessment was 300 times lower than the tolerance level assessment for children 1-6 years at the 99.9th percentile. Reduction in exposure estimates between these tiers was due to a combination of the following factors: food residue measurements in a specially designed market-basket study, government-sponsored monitoring data, probabilistic methodologies, market share information, and food processing data. This case study demonstrates that an improved understanding of the uncertainties of acute dietary exposure from pesticides is possible by using well-established statistical tools and applying them to comprehensive exposure information, including residue monitoring data, consumption data, and pesticide use information.

Pesticide residues and acute risk assessment the US EPA approach

The US Environmental Protection Agency (EPA) assesses acute dietary exposure to pesticide residues using a tiered approach, proceeding from conservative to more refined assumptions as the risk management situation requires. Toxicity and food residue data used by EPA in assessing acute dietary risk are obtained from studies submitted by chemical companies in support of pesticide registration and tolerance setting. The primary source of food consumption data used by EPA in acute dietary risk assessments is the Continuing Survey of Food Intakes by Individuals (CSFII) 1989–1991.

Unit to unit variation of pesticide residues options for acute dietary risk assessment

Within the context of the current UK policy for those commodities where the potential variability of residues in individual commodity units is taken into account, a variability factor nu, which reflects the ratio of a high level residue in the individual commodity unit to the corresponding composite residue level, is used. Data gathered from supervised industry trials in which individual items were analysed following treatment, although limited, show that variability is typically lower than that reflected by the default factors currently used and that the range of variability is reproducible over the limited range of different a.i./crop/method of application combinations investigated. In order to improve the accuracy of the acute dietary exposure estimate, the European Crop Protection Association (ECPA) proposes the following alternative to the current Tier I approach. The residue level input from a ‘hot’ unit within the dietary risk assessment should be determined using the highest composite sample residue from supervised field trials and a generic variability factor (nu) determined experimentally from supervised trials. The variability factor itself should be calculated as the 95th percentile level of the residue level found in an individual unit (or single serving portion for large crops) divided by sample mean for data produced from supervised trials. This would improve the accuracy of the Tier I approach and allow attention to be focused on particular a.i./crop/method of application combinations where the NESTI> acute RƒD (based on a Tier I assessment) and generation of individual unit residue data for the particular outlet or other mitigation may be appropriate.

Summary report of the International Conference on pesticide residues variability and acute dietary risk assessment

Click to increase image sizeClick to decrease image sizeKeywords: Pesticide Residue Variability Consumer Intake Toxicology Sampling

A perspective of pesticide residue variability and acute dietary risk assessment

The question of the variability of pesticide residues and acute risk assessment has arisen in the context of the work of the European Commission's Scientific Committee for Plants (SCP). A brief outline is presented of European Community legislation on pesticide residues and the authorization of plant protection products. It is stated that although chronic risk assessment is systematically carried out in connection with the fixing of Community MRLs, the same has not applied for acute risk assessment. The reasons for this situation have been the absence of an agreed methodology, acute reference dose (RƒD) and adequate dietary and residue data. It is stated that in the opinion of the Scientific Committee for Plants an acute risk assessment should be considered on a routine basis and that steps should be taken to ensure the availability of the necessary data. Possible implications for risk communication and the authorization of plant protection products in the EC are also discussed.

Pesticide residues variability and acute dietary risk assessment: a consumer perspective

In relation to residue variability and acute dietary intake, this paper considers whether or not consumers are adequately protected, and makes recommendations for governments and international bodies. Existing risk assessment science is inadequate to lay to rest some concerns raised by the scientific community, and it is plausible that acute exposures to pesticides from the most contaminated food may be causing adverse effects in some consumers. Consumers International recommends that: (1) analysis and regulation of pesticides with a common mechanism of action (e.g. organophosphate insecticides) be conducted in an integrated, aggregated manner, not on a single pesticide basis; (2) exposure to pesticides in foods consumed in large amounts by children be reduced by revising good agricultural practices; (3) clear risk assessment policies for acute risk assessments be established at the national and international level; and (4) an additional safety factor be applied in order to protect children when establishing maximum residue limits (MRLs) for pesticides in the absence of reliable data on the effects of pesticides on children (e.g. no pesticide-specific tests on immature animals for effects on the developing brain, endocrine, or immune systems).

Estimating acute dietary intakes of chemicals.

In some cases a single dose above an acceptable daily intake could elicit an adverse effect. In other cases a cumulative dose over several days may be necessary before an effect is expressed. Estimates of acute intake must relate to what is known about the toxicokinetics of the substance, in relation to the toxicological studies associated with the relevant end point. This is because estimates of intake can vary considerably over even a few days in some circumstances. Acute reference doses should therefore be qualified by an exposure interval. Default values can introduce considerable conservatism into intake estimates. Techniques for estimating acute intakes are very varied. They can range in complexity from conservative screening methods to sophisticated techniques designed to simulate real situations. Monte Carlo models allow for the distributions of chemical concentrations and food consumption patterns to be taken into account. For acute dietary risk assessments very high upper percentile cutoffs are sometimes applied, even as high as 99.9%. However, assumptions applied in such methods can lead to misleading results. Great care must also be used when interpreting such statistics because uncertainty and inaccuracy in the data increase considerably in the upper "tail" of the distribution.

Exposure endpoint selection in acute dietary risk assessment.

Current USEPA Office of Pesticide Program approaches to acute dietary risk assessment do not adequately address uncertainty in the distributional analysis of exposure. This is especially true with respect to regulatory decision points (bright lines) located at the far extreme of the cumulative output distribution. Use of the 99.9th centile as a risk assessment endpoint necessitates confidence in food consumption and residue input distributions that cannot be demonstrated with currently available data and analysis approaches. Even for a pesticide with a rich residue database, data limitations are sufficient to skew results to significantly overestimate exposure. This is compounded when extremes in food consumption are used that go beyond the stated error bounds for the database used. Risk management decision making need not consider endpoints at extremes of exposure output distributions in order for mitigation to be protective of sensitive populations. In fact, such decision making is better informed by utilizing more statistically reliable endpoint selection in the risk assessment process. The richest data content in cumulative exposure distributions occurs in regions well removed from output tails, where the pattern of exposure distribution is driven by the effects of residue concentrations. In contrast, the extreme upper tail of the exposure distribution is data poor and is characterized by high uncertainty reflecting extremes in food consumption patterns. At present, risk managers are better served with exposure endpoints removed from the highly uncertain tails of exposure distributions such as the 99.9th centile bright line. The selection of more appropriate risk management decision points should consider the nature of the distribution, the severity of the effect being assessed, and robustness of the data available for assessing acute dietary risk.