Making best use of available residue data for acute intake assessment

Risk assessment for pesticide residues in food has previously concentrated on chronic intake, probably with the assumption that if the chronic intake is acceptable, acute intake will also be acceptable. Data generation is expensive so we should extract, where possible, information useful for acute intake estimation from supervised residue trials. Residues in individual units of fruit or vegetables are more variable than the residues in composite samples and the distribution in individual units is probably best approximated by a lognormal distribution, but further evidence is needed. Theory provides a method for calculating the variability of replicate composite samples and applying it to individual units. The expected residue in the 95th or 99th percentile single fruits may then be calculated. An example for folpet residues in apples showed that the 95th and 99th percentile apples would contain 1.8 x and 2.3 x the residue in the composite sample, respectively. For abamectin in apples the 95th and 99th percentile factors were 6.7 and 15, respectively. The 95th and 99th percentile factors for azinphos-methyl in apples, based on single apple analysis, were 1.7 and 2.1, respectively.     

Unit-to-unit variability of pesticide residues in fruit and vegetables.

Pesticide residue levels (36 pesticides and some of their metabolites) were determined in the individual units taken from large samples of apples, bananas, celery, kiwi fruit, oranges, peaches and nectarines, pears, plums, potatoes, and tomatoes. The 65 large samples (generally about 100-110 units, but only 45 units of celery) were purchased at retail or wholesale outlets in the UK. The lots from which the samples were drawn originated from 17 different countries. Average concentrations in the samples were in the approximate range 0.002-2 mg kg(-1). Unit-to-unit variability factors (97.5th percentile mg kg(-1)/average mg kg(-1)), for the pesticide/product combination data sets in which >10% of samples contained measurable residues (n = 106), were in the range 1.4-9.6 (11.1 based on a value of zero for data below reporting limits). Analytical variance contributed only a small proportion (up to 11%) to the overall variance of the 106 data sets. There was no evidence of a relationship between the variability factor and the commodity, country of origin, residue concentration or the physicochemical characteristics of the pesticide. The extent of variability appears to be determined at or about the time of pesticide application. Taking non-detectable residues as half the reporting limits, the frequency distribution of variability factors was approximately log-normal, with a geometric mean of 3.4. The corresponding 95% probability limits of the variability factors were calculated to be 1.6 and 7.6.     

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 RfD (based on a Tier I assessment) and generation of individual unit residue data for the particular outlet or other mitigation may be appropriate.     

Factors affecting the estimated probabilistic acute dietary exposure to captan from apple consumption

The effect of the number of pesticide residue values below the LOQ/LOD of analytical methods, the variability of residues in individual fruits, mass of fruit units and the number of bootstrap iterations was studied on the probabilistically estimated acute exposure of consumers. The 4720 daily apple consumption data and the results of 1239 apple sample analyses for captan residues, performed within the Hungarian monitoring programme between 2005 and 2011, were used in this study as model matrix. Up to about 95th percentile exposure (µg/(kg bw·day)), simply multiplying each residue in composite samples with each consumption value gave similar estimates to those obtained with the complex procedure taking also into account the mass of and residues in individual fruits. However, the exposure above the 95th percentile calculated with the complex procedure gradually increased with increasing percentile level compared to the simple procedure. Including the high number of non-detects reduced the estimated exposure, which was the highest when only the residues measured in treated fruits were taken into account. The number of bootstrap iterations between 100 and 10,000 did not significantly affect the calculated exposure. The 99.99th percentile exposure amounted to 17.9% of the acute reference dose of 300 µg/(kg bw·day) for women of childbearing age.     

Variability of organophosphorus insecticide residues in large size crops grown in commercial farms in Brazil

Field trials were conducted in commercial agricultural areas in Brazil to determine the variability of residues of parathion methyl, diazinon and methidathion in individual units of large crops treated twice with a mixture of the three pesticides. Over 120 random samples were collected, extracted with ethyl acetate and residues determined by GC/FPD. The recoveries and their coefficient of variation were, in general, within the acceptable levels during sample analyses. Residues in papaya and mango were not affected by the position of the fruits in the plant, apparently more or less exposed to the pesticides. Variability factor υ, defined as the 97.5th percentile divided by the mean of residues in all samples taken from a field ranged from 2.0-2.6. The variability of residues within the plant contributed to about 34-61% of the field variability. The results found in this study support the variability factor of 3 adopted by the FAO/WHO for the deterministic estimation of dietary acute intake of pesticides.     

山东省主产区苹果农药残留水平及累积急性 膳食摄入风险评估

目的评估目前山东主要苹果产区的农药残留水平,为农药残留监管提供科学依据。方法对采自山东苹果主产区的110个苹果样品运用现有的标准方法进行102种农药残留分析检测,利用急性参考剂量(acute reference dose,ARf D)和国家估计短期摄入量(international estimated short-term intake,IESTI)公式评估苹果农药累积急性风险。结果山东省苹果共检出26种农药残留,多残留(2种农残及以上)样品占样品总数的78%,所有样品检出农药残留量均未超过规定的最大残留限量值;检出苹果上禁用农药灭多威和未登记农药噻嗪酮、螺螨酯、杀铃脲;有机磷类、菊酯类、三唑类和烟碱类农药在山东苹果中累积急性膳食摄入风险(%ARf D值)分别为37.7%、7.37%、0.28%和1.53%。结论山东省苹果农药残留种类较多,残留水平不高,有机磷类、菊酯类、三唑类和烟碱类农药累计急性摄入风险较小,但需重点关注苹果上禁用农药和未登记农药。     

Variability in pesticides residues the US experience

The evolution of US Environmental Protection Agency's (EPA) process for estimating potential health risks from pesticide residues in or on food is examined in light of changes in US Legislation and the variability of residue data and assumptions used to estimate dietary exposure. In the 86 years since enactment of the Insecticide Act, pesticide laws have become progressively more health-based. Passage of the 1996 Food Quality Protection Act (FQPA) requires EPA to place particular emphasis on assessing potential risk from pesticides to infants and children. Primary factors affecting the actual pesticide residues in food include frequency of application, percentage of crop treated, and the interval from treatment to harvest. Primary factors affecting the estimated pesticide residues in food include the source of the residue data, calculation techniques for non-detected residues, and the availability of data reflecting post-harvest treatments. Risk assessors must thoroughly consider these factors when assessing dietary risk to pesticides. Risk managers will need to consider these factors as a means of mitigating dietary risk from pesticides.     

Pesticide residues in apples grown under a conventional and integrated pest management system

This paper describes method validation for determination of more than 40 pesticides in apples using a GC technique. Target compounds belonged to the organochlorine, organophosphorus, carbamates, pyrethroids, triazoles, dicarboximides and strobilurins groups, among others. Sample preparation consisted of acetone extraction and subsequent cleanup/concentration by SPE with a polymer-based sorbent. Single quadrupole GC–MS operating in SIM mode and electron impact ionization was used for identification and quantification of the pesticides. Average recoveries for analytes ranged between 70 and 110% at three fortification levels – 0.01, 0.1 and 0.2 mg kg^?1. Relative standard deviations were lower than 20% for all tested compounds. Calculated limits of detection and limits of quantification were below 0.01 mg kg^?1, which were sufficiently low compared to the maximum residue levels (MRLs) established by European legislation. The proposed method was applied for determination of pesticide residue in four selected apple varieties after harvesting. Whole and processed fruits (peel and peeled fruits) were analyzed from different treatment systems: two conventional, one based on integrated pest management (IPM) and two variants based on organic production (controls). Higher levels of pesticide residues were found in apple fruits under conventional conditions. Fenitrothion and chlorpyrifos residues were detected frequently in apple peel at concentrations up to 0.45 and 0.77 mg kg^?1, respectively. The levels found in the whole fruits of the same samples were much lower than in peel and below the respective MRLs (0.5 mg kg^?1 for both pesticides). Measurable residues of triadimenol only, up to 0.05 mg kg^?1, concentrated in the peel, were found in the apples from IPM.     

Prediction of the processing factor for pesticides in apple juice by principal component analysis and multiple linear regression

The main objective of this work was to establish a mathematical function that correlates pesticide residue levels in apple juice with the levels of the pesticides applied on the raw fruit, taking into account some of their physicochemical properties such as water solubility, the octanol/water partition coefficient, the organic carbon partition coefficient, vapour pressure and density. A mixture of 12 pesticides was applied to an apple tree; apples were collected after 10 days of application. After harvest, apples were treated with a mixture of three post-harvest pesticides and the fruits were then processed in order to obtain apple juice following a routine industrial process. The pesticide residue levels in the apple samples were analysed using two multi-residue methods based on LC-MS/MS and GC-MS/MS. The concentration of pesticides was determined in samples derived from the different steps of processing. The processing factors (the coefficient between residue level in the processed commodity and the residue level in the commodity to be processed) obtained for the full juicing process were found to vary among the different pesticides studied. In order to investigate the relationships between the levels of pesticide residue found in apple juice samples and their physicochemical properties, principal component analysis (PCA) was performed using two sets of samples (one of them using experimental data obtained in this work and the other including the data taken from the literature). In both cases the correlation was found between processing factors of pesticides in the apple juice and the negative logarithms (base 10) of the water solubility, octanol/water partition coefficient and organic carbon partition coefficient. The linear correlation between these physicochemical properties and the processing factor were established using a multiple linear regression technique.     

2012—2014年青岛、深圳、大连三口岸282份进口水果和蔬菜中农药残留监测

目的掌握和了解进口水果和蔬菜中农药残留污染状况,为国家制定和完善相关标准和采取相关措施提供科学依据。方法本文采用GB/T 19648—2006《水果和蔬菜中500种农药及相关化学品残留量的测定气相色谱-质谱法》和GB/T 20769—2008《水果和蔬菜中450种农药及相关化学品残留量的测定液相色谱-串联质谱法》分析方法,对2012—2014年从青岛、深圳、大连三个主要水果和蔬菜进口口岸采集的282份水果和蔬菜样品进行了666种农药残留的检测。结果对282份水果和蔬菜样品进行农药残留测定和技术分析:未检出农药残留样品31份,占11.0%;检出农药残留样品251份,占89.0%。共检测出农药52种,频次702次。结合中国、欧盟、日本的农药最大残留限量标准,对获得的数据进行了科学的分析:进口香蕉、榴莲、火龙果、草莓的农药残留水平整体处于安全水平,应加强进口龙眼、樱桃、葡萄中农药残留的检测和监管。结论进口水果和蔬菜的农药残留检出率较高,达到89.0%,但超出中国最大残留限量标准的样品较少,只占1.1%,说明进口水果和蔬菜中农药残留整体处于安全水平。     

Phosphorous acid residues in apples after foliar fertilization: Results of field trials

The levels of phosphorous acid residues in apples after foliar fertilization with P fertilizers and after treatment with a phosphonate fungicide (Fosetyl-Al) were determined and compared. Two field trials and a glasshouse experiment, using different genotypes and plants of different age, were carried out and monitored over a three-year period. Phosphorous acid residues were found in apples after application of foliar P fertilizers. Concentrations of the residues ranged between 0.02 and 14 mg kg^-1 depending on the phosphorous acid content in the fertilizer used and the plant size and yield. The treatments induced an accumulation of the residue in the course of the experiments, which in some cases reached a level exceeding the maximum limit set by EU legislation. Residues were also detected in other plant organs, i.e., roots and buds. Plants treated with Fosetyl-Al contained phosphorous acid residues in their fruits and buds two years after the suspension of the treatment, suggesting a long-term persistence of the substance in plant storage organs. A second experiment, involving treatment of trees with seven foliar fertilizers of different composition, also induced accumulation of phosphorous acid residues in fruits. It is concluded that a wide array of foliar products containing phosphorous acid, even as a minor component, could mimic the residue effect of phosphonate fungicide treatments.     

Dietary exposure of Hong Kong adults to pesticide residues: results of the first Hong Kong total diet study

The use of pesticides and other chemicals has become a common practice in modern agriculture to enhance and stabilise crop yield, protect the nutritional integrity of food, facilitate food storage to assure year-round supplies, and provide attractive and appealing food products. With the adoption of strict good agricultural practice (GAP), only minimal amounts of pesticide residues should remain on the crops or in connected foods of animal origin up the food chain. To assess their associated health risk to local people, the dietary exposure of Hong Kong adults to residues of four groups of pesticides or their metabolites – organophosphorus pesticides (OPPs), carbamates, pyrethrins and pyrethroids, and dithiocarbamate (DTC) metabolites – is estimated in the first Hong Kong Total Diet Study (TDS). A total of 150 commonly consumed food items were collected and prepared “as consumed”. A total of 600 composite food samples were analysed for 85 pesticides or their metabolites by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These pesticides were primarily found at low levels (highest mean = 350 μg kg^?1) in food samples of plant origin such as vegetables and fruits. Dietary exposures to pesticide residues were estimated based on the analytical results and the food consumption data of the local residents. The estimated dietary exposures of Hong Kong adults to all individual pesticides were well below their respective acceptable daily intakes (ADIs). The percentage contributions of the estimated mean and 95th percentile dietary exposures to the ADIs of individual pesticides were <6% and <24% for the OPPs, <1% for the carbamates and pyrethrins and pyrethroids, and <1% and <4% for the DTC metabolites, respectively. The findings indicate that dietary exposures to all the pesticide residues analysed in this study were unlikely to pose unacceptable health risks to the Hong Kong population.     

果蔬加工过程农药残留行为研究及加工因子在风险评估中的应用

食品安全问题一直是社会关注的焦点,而果蔬中农药残留是影响食品安全的重要因素之一。果蔬产品大部分需要经过加工处理,残留在果蔬中的农药在加工过程中受到不同程度的影响,如清洗、去皮等加工对于果 蔬表面的非内吸性农药有显著的去除效果,而热处理过程对某些农药存在蓄积作用,在某些情况下也会加快分解或形成有毒的代谢产物。随着加工工艺水平不断提升,新型的加工方式在果蔬加工过程中应用越来越广泛,对农药残留影响也越发复杂。因此,本文对果蔬加工过程中农药残留行为影响进行系统综述,并总结农药残留加工因子在膳食暴露评估中的应用,以期为农药残留进行精准膳食风险评估和农药合理使用提供依据。     

3种农药在土壤-烟株系统中的迁移降解特征

为明确甲霜灵、噁霜灵和烯酰吗啉3种农药从土壤向烟草叶片的迁移降解及在不同部位叶片中的分布特征,在烟田进行灌根施药,采用GC-MS/MS测定农药残留量,研究了灌根施药方式对烟叶农药残留的影响。结果表明,灌根施药后,3种农药在土壤中的残留量逐渐降低且降解动态符合一级动力学方程;在烟叶中的残留量先升高后降低,不同部位的残留量呈现下部叶 > 中部叶 > 上部叶的趋势。甲霜灵、烯酰吗啉在施药后第7天烟叶农药残留量低于最大残留限量标准,噁霜灵在施药后第28天烟叶农药残留量仍高于最大残留限量标准。可见,按推荐高剂量进行灌根施药后,烟叶中甲霜灵、烯酰吗啉超限风险较低,噁霜灵超限风险较高。     

臭氧技术对果蔬农残去除效果的研究进展

近年来,臭氧技术在降解农药残留方面表现出良好的效果,且不会对果蔬造成二次污染,被认为是一种绿色的处理技术,其应用方式主要有熏蒸法和浸泡法两种。本文结合近年来的研究成果,综述了臭氧气氛熏蒸法和臭氧水浸泡法降解果蔬中多种常见农药的效果,以及对两种方法效果的对比;并介绍了影响臭氧作用效果的因素,包括气相温度和湿度、水温、臭氧气泡大小和pH等,以此为臭氧技术降解果蔬农残的实际应用提供理论指导。     

Matrix‐Matching as an Improvement Strategy for the Detection of Pesticide Residues

More than 90% of the pesticides residues in apples are located in the peel. We developed a gas chromatography/ion trap tandem mass spectrometry method for investigating all detectable residues in the peel of 3 apple varieties. Sample preparation is based on the use of the Quick Easy Cheap Effective Rugged and Safe method on the whole fruit, the flesh, and the peel. Pesticide residues were quantified with solvent‐matched and matrix‐matched standards, by spiking apple sample extracts. Matrix effects dependent on the type of extract (fruit, flesh, or peel) and the apple variety were detected. The best data processing methods involved normalizing matrix effect rates by matrix‐matched internal/external calibration. Boscalid, captan, chlorpyrifos, fludioxonil, and pyraclostrobin were the most frequently detected pesticides. However, their concentrations in the whole fruit were below European maximum residue levels. Despite negative matrix effects, the residues in peel were detected at concentrations up to 10 times higher than those in whole fruits. Consequently, other pesticide residues present at concentrations below the limit of quantification in the whole fruit were detected in the peel.     

成都市售果蔬中农药残留水平分析及慢性膳食风险评估

了解成都市果蔬中农药残留污染现状及其对成都市居民的膳食风险水平.采集成都市果蔬大型农贸市场和超市的9类果蔬共203份样品,采用改良的GB 23200.113-2018 QuEChERS前处理方法,结合气相色谱-三重四级杆串联质谱对48种农药进行检测,分析成都市果蔬中农药残留现状,并结合大城市居民的果蔬消费情况和食品安全...     

Baby food production chain: pesticide residues in fresh apples and products.

During 3 years of a monitoring programme, 522 samples of fresh apples, six brands of fruit purées and various types of fruit baby food prepared from these materials were analysed. Each sample was examined for the presence of 86 GC amenable pesticide residues. The reporting limits of the procedure employed for sample analyses were in the range 0.003-0.01 mg kg(-1). Pesticide residues were detected in 59.5% of the samples of fresh apples. However, maximum residue levels (European Union MRLs) were exceeded only in 1.4% of samples. The levels of residues in 'positive' fruit purées were substantially lower, overall with residues detected in 33% of samples. Fruit baby food represented the commodity with the lowest incidence of residues being detected in only 16% of samples. The 0.01 mg kg(-1) MRL was exceeded in 9% of these products. Multiple residues were found in 25% of fresh apples and in 10% of fruit purées. None of fruit baby food samples contained more than a single residue. Organophosphorus insecticides and fungicides representing phtalimides, sulphamides and dicarboximides were the most frequently found residues. To obtain more knowledge on the fate of residues during fruit baby food production, processing experiments employing apples with incurred residues (fenitrothion, phosalone and tolylfluanid) were conducted. Washing of apples did not significantly reduce the content of pesticides. Steam boiling followed by removal of peels/stems was identified as the most efficient steps in terms of residues decrease (phosalone) or complete elimination (fenitrothion and tolylfluanid).     

天津地区果蔬农药施用状况的调查

目的调查天津农民在种植水果蔬菜过程中的农药施用状况。方法对全年随机抽取的3360名农户进行问卷调查，内容涉及施用农药的种类、频次、施药间隔及安全间隔期等。结果2005年天津市施用于水果、蔬菜的农药种类共计140种，以有机磷类杀虫剂为主，占20．7％；按施药频次排序，前10位主要为低毒低残留农药，其中有机磷类杀虫剂一遍净（吡虫啉）施用频次最多，占全年总频次的15．3％；全年总违规施药率为1．59％，四季农药违规施用率差异有统计学意义（P〈0，01），第三季度违规施用率最高，为2．57％；部分调查果蔬中施药次数违规率较高．其中苹果中氰戊菊酯的施药次数违规率高达95．8％。结论国家明令禁止的农药违规施用率明显好转，但部分农药的施药次数及安全间隔期违规现象比较严重。     

A preliminary assessment of consumer’s exposure to organochlorine pesticides in fruits and vegetables and the potential health risk in Accra Metropolis,Ghana

Accra Metropolis is the major recipient of agricultural produce in Ghana, with almost the entire population depending on rural agricultural activities for subsistence. To increase agricultural produce, various forms of pesticides are normally used in fruits and vegetable farming. The consequence is that several cases of pesticide poisoning have been observed. In this preliminary study, a field survey was carried out to assess the knowledge, attitudes, and peoples’ perception concerning the use of pesticides by farmers in fruit production. The residual concentrations of selected pesticides in pawpaw, imported apples and tomato samples and the potential health risks associated with the exposure to these pesticides were also assessed. The field survey data indicated that more than 70% of the participants reported one or more poisoning upon fruits consumption resulting in pesticide-related illnesses. Pesticide residues in the various environmental samples were determined by gas chromatography with electron capture detector (GC-ECD). The results showed that, the levels of pesticide residues varied from <0.01 μg/g to as high as 0.11 μg/g depending on the pesticide monitored. The analysis of health risk estimates revealed heptachlor, heptachlor epoxide, endrin aldehyde, and endrin ketone levels exceeded the reference dose, suggesting a great potential for systemic toxicity in children considered the most vulnerable population subgroup. Lastly, the public is in the know of pesticide residues in fruits and calls for the curtailing of pesticide use on fruits and vegetable production via educational programmes for farmers on control and safer use of pesticides.