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Evaluation of the Results of Pesticide Residue Analysis in Food Sampled between 2017–2021.

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05 July 2023

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06 July 2023

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Abstract
As required by the EU legislation and the national risk management duties, the pesticide residues were determined by four specialized laboratories in 9,924 samples taken from 119 crops of economic importance and imported foodstuffs during 2017-2021 in Hungary. The screening method applied covered 622 pesticide residues as defined for enforcement purposes. The limit of detection ranged between 0.002-0.008 mg/kg. The 1.0% violation rate was lower than in the European Union for all commodities. No residue was detectable in 45.9% of the samples. For detailed analyses of the results, eight commodities (apple, cherry, grape, nectarine/peach, sweet peppers, and strawberry) were selected as they were analyzed over 195 samples and contained most frequently residues. Besides testing their conformity with national MRLs, applying 0.3MRL action limits for pre-export control, we found that 73% of the sampled lots would be compliant with ≥90% probability based on second independent sampling. Multiple residues (2-23) in one sample were detected in 36-50% of the tested lots. Noting the provisions of integrated pest management and the major pests and diseases of selected crops, normally 3-4, exceptionally 7-9 active ingredients of different mode of actions should be sufficient for their effective and economic protection.
Keywords: 
Subject: Environmental and Earth Sciences  -   Environmental Science

1. Introduction

Many cultivated plants used as food, feed or industrial raw material must be protected from pests, diseases and weeds. Chemical substance-based pesticides and micro-organisms are used for their protection. The popularity of the so-called bio-products, grown practically without or limited kinds of pesticides is increasing. However, their proportion in the total production is low. According to the latest information, bio-farming was conducted in 9.2% of the whole agricultural area within the European Union (in Hungary about 6%) in 2020 [1].
The pesticides are toxic substances. Their authorization and use are strictly regulated world-wide. In the European Union (EU) the European Parliament (EP) and the Council or the Council alone issue regulations concerning the placing of the chemical and micro-biological plant protection products on the market [2,3,4,5,6].
Each Member State shall take a sufficient number and range of samples to ensure that the results are representative of the market, taking into account the results of previous control programs. Such sampling shall be carried out as close to the point of supply as is reasonable, to allow for subsequent enforcement action to be taken [6].
Due to legal obligations and based on their own interest many national authorities regularly monitor the pesticide residues in food and feed products. For example, extensive control is in place and the results are published by Austria, Australia, Germany, Japan and the USA [7,8,9,10,11]. The main objectives of the programs, for instance, is to provide data and information for testing the compliance of marketed foodstuff with the legal limits, preventing marketing products with unacceptable residues, performing dietary exposure assessment, and managing the risks identified [12,13].
Besides the nationwide monitoring programs, researchers often determine the pesticide residues in/on specialty crops or specific group of plant commodities [14,15,16,17,18] including feed [19], and fish [20,21]. They perform dietary risk assessment based on the residue levels found and corresponding food consumption data. Moreover, various non-profit activity groups, such as the Environmental Working Group (EWG) in the USA conduct surveys of pesticide residues and other toxic chemicals in food and environmental samples to provide information needed to make “smart, healthy choices” [22]. The EWG recently published the list of “dirty dozen” and “clean 15” commodities based on the frequency and concentration of detected pesticide residues. Our findings in Hungary largely agree with those of EWG.
In addition to the national control programs, the European Commission (EC) has selected certain foodstuffs constituting the major components of the diet in which the pesticide residues should be monitored since 2009. The changes in residue levels are monitored within the compulsory coordinated multiannual control programs [23]. The European Food Safety Authority (EFSA) evaluates the results of the national and coordinated monitoring programs. The results show that out of 96,302 and 88,141 samples 2.3% and 3.6% were non-compliant in 2019 and 2020, respectively. Based on the acute and chronic risk assessment it was concluded that the residue levels unlikely pose any concern for consumer health [24,25].
Despite the low frequency of residues exceeding the MRLs, 40% of the European citizens consider the pesticide residues in food as a health risk [26].
For testing the conformity to MRLs, the residues defined for enforcement purposes [27,28] should be determined in the portion/part of commodity to which the MRLs apply, and which is analyzed [6,29]. The test portion should represent the composite sample containing the specified minimum number of primary samples and mass of sampled material [30,31]. For the evaluation of the test results the measurement uncertainty should always be considered according to ISO Standard 17025 and Codex GL [32,33]. Where the compliance of locally marketed products is tested, the combined relative uncertainty of the within laboratory reproducibility (CVL) [34] or the 0.25 default value introduced in EU [35] should be used. For controlling imported products, if available, the specific import MRLs apply. However, when the results of pre-export control are evaluated the combined uncertainty of the whole process, including that of sampling, ought to be considered [36] in combination with a properly selected action limit [37,38,39].
The sampling uncertainty was determined based on the analyses of over 10,000 duplicate supervised trial results [38,40]. The practical application of the action limit was explained in detail in a recent article [36].
The objectives of this article are to present the summary results of the Hungarian national pesticide residue monitoring conducted between 2017-2021, evaluate, as an example, the compliance of six selected commodities with the Hungarian (EU) MRLs, and predict the potential acceptability of the sampled lots if they were exported to the EU. Moreover, critically review the plant protection practice that led to multiple residues detected in the selected crops.

2. Materials and Methods

2.1. Sampling

The sampling plan was prepared by the Central Office of the Hungarian National Food Chain Safety Office (NFCSO) considering, in general, the principles of risk- based monitoring programs [41] and the coordinated multi-annual control plan of the European Commission [23,42].
The plant protection or quarantine inspectors took the samples at farm gates, border control points and in wholesale markets or large supermarkets in the whole country. The specified number of primary samples and the minimum mass of the composite sample were collected from randomly selected positions according to the Codex [30] and EC sampling standard/instruction [31] noting the minimum mass of the composite sample as well. After collection, the samples were transported in cooled transport vans to the laboratories. The sampling records were directly uploaded to the central online database. The laboratory staff could download and insert the data relevant to the analyses of samples in the laboratory sample registry book [36]. The authorized officials of NFCSO took the necessary official control actions. The system enables access to records by authorized persons from their offices to observe the progress of the operations in real-time. Moreover, it eliminates repeated manual data entry and potential errors.

2.2. Analyses of pesticide residues

Four laboratories of NFCSO were involved in the analyses of pesticide residues in plant commodities. The laboratories considered the samples of unknown pesticide treatment history even if the pesticide applications were indicated on the sampling record sheet. The scope of the screening included over 600 residues with 0.002-0.008 mg/kg limit of detection which enabled detecting any unauthorized use of pesticides, too. The laboratories applied different versions of the QuEChERS methodology depending on the physical-chemical properties of the residues [43,44,45]. The pesticide residues are divided in subgroups depending on the methods and detection conditions applied. Some very polar compounds such as glyphosate and glufosinate and some others such bromid-ion and dithiocarbamates required single residue methods.
The laboratories worked in coordination and shared the tasks of method validation and performance verification. While the rolling programme of the recovery tests were carried out in each laboratory at the LOQ and MRL levels. The criteria for the acceptable performance parameters established by the European Commission [35] were the basis of their internal quality control. The performance of the laboratories is verified by their good results achieved in the European Proficiency tests similar to that reported previously [46].

2.3. Assessment of compliance with legal limits (MRL)

For making fair decision on the compliance of a sampled lot with the relevant MRLs, the uncertainty of measured residues should always be considered according to the ISO Standard 17025 [32]. The practical application of the principles is explained in detail by Ambrus et al [34].
There are two principally different situations:
the sampled lot is intended for the local market;
the lot is sampled before export.
Case (a): when a commodity is placed on the local market the average residue content of the tested composite sample (R) should be equal or lower than the corresponding MRL taking into account the expanded within laboratory reproducibility relative standard deviation (CVL):
R − 2 × R × C V L ≤ M R L
If the residue calculated with the expanded uncertainty (equation 1) exceeds the MRL, the sampled lot should not be marketed.
However, an imported product is rejected in the European Union only if the measured residue (R’) adjusted with its combined relative uncertainty exceeds the MRL. For facilitating uniform decision, a default among laboratories relative reproducibility of 0.25 is used within the EU [35].
R ' − 2 × 0.25 × R ≥ M R L
It practically means that the sampled lot would only be accepted if the measured residue, R’, is equal to or less than 2 times the MRL.
Applying this rule, the probability of wrongly rejecting a lot by the importing country is about 2.3-2.5% which is a fair treatment according to the principles of Codex GL on settling dispute [33].
EFSA applies the same principle and distinguish cases of exceedance of MRL in the evaluation of monitoring data. For example, in 2020 the analyses of 88,141 samples were reported. The residues exceeded the MRL in 5.1% of the samples of which 3.6% were non-compliant after taking the expanded measurement uncertainty into account [25].
In Case (b) the compliance of the exported commodity will be decided by the importing country based on the analyses of an independently taken composite sample at the border control point. Consequently, the likely upper 95-98% tail of the distribution of the residues in repeated composite samples should be predicted and compared to the MRL of the importing county to make sure that the exported lot will be accepted. Therefore, for pre-export control the sampling uncertainty should also be accounted for in the combined uncertainty of the whole determination process (CVR) [34,37]. For this reason, an action limit (AL) lower than the MRL should be used as acceptance criterion.
A L + k × C V R × A L
=MRL
A L = M R L 1 + k × C V R
The value of k depends on the targeted compliance level that is typically 95-98%.
Applying an action limit for facilitating compliance with export MRLs is relatively a new approach. In addition to pesticide residues [36,47], it was recently applied for mycotoxins [48] and gluten in oat groats [39]. In view of its applicability for three different analyte-matrix combinations, its use can be generally recommended during pre-marketing control.
Based on the evaluation of over 10,000 supervised trial results, Farkas and co-workers [38,40] concluded that a default action limit should be chosen around 0.3MRL to assure with about 95-98% probability that the sampled product would be accepted in the EU taking into account the decision rule specified with equation 2.
The pre-export evaluation of residues in tested commodity is illustrated with the example of acetamiprid residues in apple (MRL=0.4 mg/kg). Figure 1 shows the operation characteristic curves if single sample is taken from a lot and 0.12 mg/kg, 0.15 mg/kg and 0.2 mg/kg action limits are considered. Moreover, the targeted compliance level is 98% (the probability of rejection is 2%).
The figure shows the probability of detection of pesticide residues in composite samples taken from the tested lot. The probabilities of finding ≥0.4 mg/kg residue in repeated samples are 2, 4.5 and 12.5% if the samples did not contain residues above the action limits of 0.12, 0.15 and 0.2 mg/kg respectively. Moreover, the figure indicates that the probability of finding residues ≥0.8 mg/kg decision limit (equation 2) is practically zero if action limits 0.12 and 0.15 mg/kg were applied at the time of pre-export sampling of the apple lot. On the other hand, residues above the 0.8 mg/kg may occur at low probability if an AL of 0.2 mg/kg were considered.
The relative sampling uncertainty (CVS) varies between 1.2 and 1.7 in case of fruits and vegetables [38,40]. Therefore, to be on the safe side a default action limit of 0.3MRL is recommended for general use.
Refined action limit can be selected based on the CVS values determined by Farkas and co-workers.

3. Results

3.1. Summary of the results of pesticide residue monitoring during 2017-2021

During the period of 2017-2021 pesticide residues were determined in 9,924 samples taken from 119 crops. Altogether over 2.6 million analyte-sample combinations were tested. In view of the very large database, the results obtained by the analyses of six commodities containing the most frequently detected residues were selected, as example, for their evaluation in this article. Table 1 shows the main parameters and results of the tests carried out.
Table A1 and Table A2 indicate the number of samples in which the active substances were detected. The residue components included in the definition of residues were tested with the methods applied, but they are not listed separately in the table. Nevertheless, the active substance concentration reported was calculated from their measured concentrations expressed in the reported active subsatnce equivalent.
The table indicates the frequency of occurnece of various reidues and provides guidance for the relevance of their inclusion in the scope of the screening method(s) applied. It is especially important if selected ion monitoring detection mode is used. Moreover, it should be emphasised that the 0.01* mg/kg default limit is applicable for all substances for which MRL has not been established.

3.2. Assessment of compliance of residues with MRLs

3.2.1. Commodities marketed in Hungary

The authorizations of several active substance were withdrawn by the European Commission during 2017-2021. After the grace period, these substances must not be used, and their residues should not be present in detectable concentration in/on food and feed commodities. The R>MRL cases indicated in Table 1 for the selected six commodities resulted from the unauthorized use of these substances.
As it was the case in other Member Countries of the EU [24,25] multiple residues were detected in many samples at varying concentrations below the corresponding MRLs. The summary of findings related to the selected crops is given in Table 2 and Table 3. A few samples contained residues above the corresponding MRLs: one sour cherry [dimethoate (0.052 mg/kg) + omethoate (0.101 mg/kg) in 2018]; two peppers [chlorpyrifos (0.058 mg/kg and 0.036 mg/kg) in 2020 and 2021]; three strawberries [flonicamid (0.32 mg/kg), tebuconazole (0.17 mg/kg) in 2019 and propiconazole 0.064 mg/kg) in 2020]. The residue concentrations were generally low indicating that the pesticides were likely applied along the four weeks period before harvest and the pre-harvest intervals were considered. The acute exposure deriving from those multiple residues belonging to one cumulative risk assessment group might raise concern. Therefore, the exposure of consumers to pesticide residues will be evaluated in another article. Moreover, we consider in section 3.3 if the presence of multiple residues reflects the good plant protection practice.

3.2.2. Prediction of potential compliance with MRLs if the sampled products would be exported

We postulate that the tested lots might have been exported to EU and subjected to repeated sampling by the importing country as part of the border control. To verify compliance with export MRLs the sampling uncertainty shall also be included in the combined uncertainty of the results.
Taking the recommended 0.3MRL action limit, we evaluated the potential compliance of the tested lots considering the residues of all active substances detected in the samples taken from the selected commodities.
The results, shown in Table 2, indicate the number of lots that would comply with the given high probability if any of the active substances analyzed were applied in them except those which are listed individually.
Of the detected residues in the selected commodities the grace period is over for a number of active substances. They should not be presents in detectable concentration (MRL=0.01*) in the samples:
  • apple: chlorothalonil, chlorpyrifos, chlorpyrifos-methyl, fenhexamid, imidacloprid and methoxyfenozide;
  • grape: chlorpyrifos, chlorpyrifos-methyl, diflubenzuron, dimethoate/omethoate, famoxadone, iprodione, pirimicarb and thiophanate-methyl;
  • cherry: chlorpyrifos, dimethoate, omethoate, prochloraz;
  • peach: chlorpyrifos, chlorpyrifos-methyl, diflubenzuron, fenbuconazole, imazalil, imidacloprid and propamocarb;
  • peppers: buprofezin, chlorpyrifos-methyl, napropamid, triadimefon, triadimenol.
In addition, the residues of glyphosate (0.1*), captan and THPI (0.03*), thiophanate-methyl (0.1*) should not be present in detectable concentrations in the commodities listed in Table 2.
The test results obtained during the grace period are not relevant for the present assessment and were not considered. The restricted substances should be included in the scope of screening methods with LOD lower than the MRLs (LOQ values) indicated with asterisk.
Moreover, those lots containing them in detectable concentration must not be exported or marketed in Hungary either.

3.3. Evaluation of plant protection practice

Multiple residues were detected in many samples at varying concentrations below the corresponding MRLs. Based on their residue levels, the majority of the detected active substances were likely applied in the period of four weeks before harvest.
The summary of findings related to the selected crops is given in Table 3 and Table 4.
At the first sight the number of active substances look surprisingly high. However, one of the most important tools for avoiding the pest resistance to pesticides is to use alternate or tank-mix substances of different chemical structures and modes of actions, and limiting the number of applications of the chemicals with site-specific modes of action, and avoidance of their eradicant use. It is the general recommendation to resistance management in the agriculture. Pesticide resistance has been documented in a large number of key diseases and pests of the selected crops, e.g. apple scab, powdery mildews, downy mildew, gray mold, brown rot of stone fruits, codling moth, cotton bollworm, white flies, several aphid and spider mite species, etc. In the last decade the authorization of several broad-spectrum insecticides was withdrawn (e.g. organophosphates, several synthetic pyrethroids and zoocide carbamates). Both plant pathogens and pest species differ significantly, for this reason there is no possibility to control all with only 1-2 active substances. Therefore, the growers must combine and apply different plant protection products.
Nevertheless, the residues of 23, 15, 12 and 11 different active ingredients detected in apple, pepper, grape and strawberry, respectively, are considered high. In an average year the diseases and pests can be effectively controlled with lower number of applications. Depending on the weather conditions and the pest situation in the given orchard, 2-2 combined applications are justified against plant pathogens and pests in apple, cherry, peach and nectarine within the period of four weeks before harvest. In peppers and strawberry probably, more applications are reasonable in this period. There is no general rule for the number of treatments that depends on the life cycles and flight activity of the pests, the developmental stages of the crops, the weather conditions during the growing season (temperature, precipitation, humidity), the variety, the training system, the presence of insect pollinators, etc. For choosing the compounds to be applied, besides the pest communities actually present in the orchard and vineyard, it is very important to take into account the mode of action of the active substances. To carry out integrated pest management, the continuous and precise pests forecast (monitoring, scouting, pheromone trapping) in the orchard is necessary.
In apple the most important diseases and pests are apple scab, powdery mildew, codling moth, leaf miner moths, aphids and woolly aphid. In certain years fire blight, tortrix moths, spider mites and apple clearwing can cause problems, too. On the average, the applications of 3-4 active substances (Table 4), is well justified. Even 8-9 active substances may be required, because the need for resistance management.
During the four weeks period before harvest pesticide treatments are required to control of codling moth and tortrix moths (acetamiprid, etofenprox, indoxacarb, chlorantraniliprole, thiacloprid), spider mites (etoxazole, spirodiclofen), apple scab and powdery mildew (difenoconazole, dithianon, fluopyram, pyraclostrobin, pyrimethanil, tebuconazole) and the storage diseases (cyprodinil, fludioxonil, fluopyram, pyraclostrobin).
In sour cherry the pesticides used for the control of the most important diseases and pests were as follows: cherry fruit flies and black cherry aphid (acetamiprid, deltamethrin, lambda-cyhalothrin, pirimicarb and thiacloprid), brown rot and anthracnose (boscalid, captan, cyprodinil, dithiocarbamates, fenhexamid, fludioxonil, fluopyram, penconazole, prochloraz and tebuconazole). The period of last decade of May till middle of June is of crucial importance in pest management of this stone fruit in Hungary. The average of 3-4 active substances sprayed per growing season is not a high number because of the numerous diseases and arthropod pests.
In table grape the growers must control effectively several key diseases and pests which infest both leaves and berries, such as powdery mildew, downy mildew, gray mold (botrytis blight), grape berry moths, Northern American grapevine leafhopper (Scaphoideus titanus) and phytophagous mites during the growing season. The vast majority of the active substances were applied against diseases caused by fungi. On the average of 3-4 active substances applied per growing season is not a high number. The number of target pests and diseases and the number of applications are closely related. Because of the different fungal pathogen species, different active substances have to be applied against powdery mildew and gray mould. Similarly, for the control of grape berry moths an acaricide which efficacious against spider mites is not suitable.
In the period of flowering and fruit development the effective control of powdery mildew (azoxystrobin, fluopyram, metrafenone, myclobutanil, penconazole, pyraclostrobin, spiroxamine, tebuconazole), downy mildew (cyazofamid, dimethomorph, dithiocarbamates, fluopicolide, folpet, mandipropamid, metalaxyl), gray mold (boscalid, cyprodinil, fenhexamid, fenpyrazamin, fludioxonil, fluopyram, folpet, iprodione, pyrimethanil), grapevine leafhopper (chlorpyrifos, imidacloprid, lambda-cyhalothrin, spinosad, spirotetramat, thiamethoxam) and grape berry moth (chlorantraniliprol, chlorpyrifos, lambda-cyhalothrin, spinosad, tau-fluvalinate) is essential.
In case of nectarine and peach the relevant diseases are: peach leaf curl, peach shot hole, bacterial dieback, Cytospora canker, brown rot, peach twig borer, Oriental fruit moth, aphids, scale insects and mites. Therefore, spraying is necessary to control peach twig borer and Oriental fruit moth (acetamiprid, indoxacarb, lambda-cyhalothrin), aphids (acetamiprid, flonicamid, pirimicarb) and brown rot (boscalid, captan, cyprodinil, fenhexamid, fenpyrazamine, fluopyram, penconazole, tebuconazole). On the average, treatments with 3-4, even 7-9 active substances per year are justified.
For the successful peppers production, the efficacious control of the following key diseases and pests is essential, i.e. root rots, bacterial spots, powdery mildew, soil-dwelling insects, thrips species and cotton bollworm. In the period of flowering and fruit development the effective control of thrips species (abamectin, acetamiprid, spinosad, thiamethoxam), aphids (acetamiprid, flonicamid, pirimicarb, thiacloprid, thiamethoxam), cotton bolworm (chlorantraniliprol, lambda-cyhalothrin, spinosad) and powdery mildew (azoxystrobin, boscalid, difenoconazole, penconazole, pyraclostrobin) is necessary. Besides fungicides and zoocides, in peppers herbicides were also used and detected in some samples (napropamid, pendimethalin).
The strawberry growers must control effectively several key diseases and pests, such as soil pathogens, leaf diseases, gray mold (fruit rot), strawberry blossom weevil, strawberry rhynchites, strawberry root weevil, aphids and strawberry mite. The number of target pests and diseases and the number of applications is closely related. On the average of 3-5 active substances applied per growing season is not a high number because different pesticides have to be used to control, for instance, soil pathogens and leaf diseases or gray mold, or aphids and mites.
In the period of flowering and fruit development the control of gray mold (boscalid, cyprodinil, fenhexamid, fenpyrazamin, fludioxonil, fluopyram), strawberry blossom weevil and aphids (lambda-cyhalothrin, thiacloprid, thiamethoxam) and strawberry mite (abamectin, bifenazate, hexythiazox) is very important.

4. Discussion and conclusions

Altogether the residues of 622 pesticide active ingredients were analyzed in 9,924 samples taken mostly from 119 fruits and vegetables of economic importance grown in Hungary as well as imported during 2017-2021. The pesticide residue-sample combinations amounted to over 2.6 million. The risk-based sampling plan was developed by the NFCSO. It also incorporated the samples specified by the multi-annual control program of the European Commission [42].
The analyses were performed in laboratories accredited according to ISO 17025 Standard [32]. They applied the appropriate variant of the QuEChERS methodology in combination with LC-MS/MS and GC-MS/MS detection [43,44,45].
The analysts worked in close cooperation in implementing the work program, method validation and confirmation of critical results but performed separately the rigorous internal quality control program. The accuracy of their results and in general the technical level of laboratory analyses was demonstrated with the successful participation in proficiency tests covering fruits, vegetables and cereals.
In view of the very large number of results, 6 crops having the largest frequency of detectable pesticide residues were selected for the illustration of the results and our evaluation methods.
Out of the 9,924 samples/lots 102 (1.0 %) contained residues above the Hungarian (EU) MRLs. The violation rate was lower than that reported by EU Members countries (4.5% (2018), 3.9% (2019), 3.6% (2020) [24,25]. In Hungary, the violation of the MRLs resulted from the use of unauthorized pesticides which were applied after the grace period expired. Such a situation requires action from the regulatory agency. The growers were fined and advised on the changed authorization status of the pesticides that they misused to reduce the chance of placing plant commodities containing unauthorized residues on the market in the future.
In addition to the assessment of the compliance to legal MRLs of commodities marketed in Hungary, we examined the fictive situation of their potential export to the EU. For making a decision whether the tested lot would contain residues below the corresponding MRLs upon the border control, we used an action limit of 0.3MRL for the evaluation of detected residue concentrations. In view of its applicability for three different analyte-matrix combinations [37,39,48], we recommend its use generally for pre-marketing control.
In the evaluation of residue data, the proportion of lots that contained residues ≤0.3 MRL was considered compliant. It was found that all tested residues in 79% of apple, 83% of cherry, 88% of grape, 89% of peach/nectarine, 73% of pepper and 76% of strawberry lots would comply with the import MRLs with >90% probability. The residues of active substances that would lead to a lower level of probability of compliance were identified.
Our results draw attention to a very important practical situation. Notwithstanding that the residues in tested lots conformed with the EU MRLs based on the first sampling, it cannot be excluded that certain proportion of these lots would contain higher residues and be rejected based on the results of repeated independent sampling, even if both sampling was representative, and the analyses provided accurate results. The inevitable variation of the results of repeated random sampling is caused by the very heterogeneous distribution of residues in primary samples [49,50] and consequently in the composite samples too. Therefore, to avoid rejection of export shipments, the lots to be exported should be selected based on pre-export sampling and analyses. Their results should be evaluated applying appropriate action limit.
The wide scope of the screening methods and low LOD values enabled the detection of all residues present even in trace concentrations. As a result, we found that 36-50% of samples of selected crops contained multiple residues ranging from 2 to 23. The frequency of multiples residues was in the same range in European countries where the average frequencies reported were 29% (2018), 28% (2019) and 28.9% (2020) of the samples. The highest percentages of multiple residues were in sweet peppers/bell peppers, apples, oranges, pears, strawberries, table grapes, mandarins and peaches in 2020. The maximum number of residues was found in a strawberry sample (35) and a dried vine fruit sample (28) in 2020 and 2019, respectively [24,25].
The residue levels were typically low, indicating that some of the pesticides were applied well before the harvest of the crops. Since the residue levels are compared to the corresponding MRLs [6,51] individually, the samples containing multiple residues complied with MRLs.
Observing the high number of pesticide residues present in some samples, we examined whether the application of those active substances could be justified based on the principles of integrated pest management and good practice in the application of pesticides. Considering the major pests and diseases of the selected crops as well as the need for the rotation of active substances and treatments with mixtures of pesticides to reduce the chance for the development of resistance, we concluded that the use of 23, 15, 12 and 11 different pesticides in apple, pepper, grape and strawberry, respectively, are not representing good plant protection practice. On average, the application of 3-4 active substances in apples is well defensible. Similarly, 3-4 pesticide treatments of cherry and peach and 3-5 in strawberry during the growing season are reasonable. Even 7-9 active substances may be needed for effective protection under special circumstances and for resistance management.
When high number of pesticide treatments is witnessed, even though there is no risk of the health of the consumers deriving from the exposure to pesticide residues, the farm owners should be informed and advised to seek the help of a plant protection specialist who would examine the actual growing conditions prevailed during the growing season and advise the farmers on the effective and economical use of pesticides.
Considering the results of our evaluation based on the selected crops, we can conclude that the national monitoring program conducted during the past 5-years period served its purpose and met the requirements of the European Commission specified in 396/2005 regulation. Moreover, it provided well-supported information for the regulators on the appropriate level of plant protection practice in Hungary.
Nevertheless, the monitoring of pesticide residues should be continued to provide up-to-date information for exporters of agricultural products and regulators to make timely action assuring the safe and effective use of pesticides, if necessary.

Author Contributions

Conceptualization, original draft preparation, manuscript finalization, Á.A.; data collection and formatting A.V.; methodology Á.A., H.S.-D. and G.R.; review, Á.A., G.R., A.V. and J.S.-C.; editing J.S.-C. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

Appendix A

Abbreviations
AL Action limit
AS Active substance
EFSA European Food Safety Authority
FAO Food and Agriculture Organization
GAP Good Agricultural Practices
HFCSO Hungarian Food Chain Safety Office
JMPR Joint Meeting on Pesticide Residues
LOD Limit of detection
LOQ Limit of quantification
MRL Maximum Residue Limit
US FDA United States Food and Drug Administration
WHO World Health Organization

Appendix B

Table A1. Summary of number of samples and active substances tested.
Table A1. Summary of number of samples and active substances tested.
Number of tests Apples Cherries Grapes Green peppers Peaches Active substances1
No. of samples tested 803 122 783 588 468 349
No. of residues - matrix combinations tested 227571 32962 113132 165388 90851 60458
No. of ASs tested 459 441 459 459 445 447
Table A2. Number of samples in which the active substances were detected.
Table A2. Number of samples in which the active substances were detected.
Active substances1 Apples Cherries Grapes Green peppers Peaches Strawberries
2,4-D 202 52 212 148 80 99
2,4-DB 48 12 42 19 13 32
2-Phenylphenol 588 81 499 438 367 153
3,5-Dichloroaniline 219 42 156 139 68 95
3-Chloroaniline 158 40 125 90 53 70
Abamectin (sum) 449 41 166 346 190 92
Acephate 759 99 386 573 302 204
Acetamiprid 765 108 394 586 321 212
Acetochlor 694 102 316 489 278 178
Aclonifen 163 10 63 92 61 32
Acrinathrin 766 102 389 577 311 206
Alachlor 542 81 273 381 192 140
Aldicarb (sum) 572 92 343 471 248 165
Aldrin and Dieldrin (sum) 724 104 387 568 312 205
Alphamethrin 184 29 77 145 91 39
Ametoctradin 404 38 157 257 148 70
Ametryn 370 52 203 214 122 107
Amidosulfuron 140 18 36 97 75 35
Aminopyralid 14
Amitraz (sum) 161 40 126 94 53 68
AMPA 14 1 11 15 4 2
Atraton 207 42 140 122 61 75
Atrazine 593 95 287 423 239 162
Azamethiphos 247 18 67 134 88 25
Azinphos-ethyl 700 103 320 494 287 178
Azinphos-methyl 769 103 393 581 318 206
Aziprotryne 370 52 203 214 122 107
Azoxystrobin 765 110 394 586 322 211
Beflubutamid 137 18 34 96 75 33
Benalaxyl (sum of isomers) 698 104 317 490 273 177
Bendiocarb 122 11 41 107 44 15
Benfluralin 379 71 210 289 131 108
Bentazone (sum) 218 41 104 207 103 48
Benthiavalicarb (Benthiavalicarb-isopropyl) 169 10 131 102 61 34
Benzovindiflupyr 151 13 320 83 31 8
Bifenazate 163 10 359 92 61 32
Bifenox 694 102 331 490 279 178
Bifenthrin (sum of isomers) 769 108 155 588 322 212
Biphenyl 565 79 316 417 210 151
Bitertanol (sum of isomers) 759 107 617 574 307 209
Bixafen 709 107 396 493 290 177
Boscalid 773 108 308 588 322 212
Bromfenvinfos 167 12 396 98 64 37
Bromide ion 14
Bromophos-methyl 688 105 309 473 288 177
Bromophos-ethyl 691 105 170 477 287 177
Bromopropylate 771 108 395 587 321 212
Bromoxynil and its salts 382 65 356 246 132 106
Bromuconazole (sum of diasteroisomers) 696 108 63 499 290 184
Bupirimate 779 111 393 585 324 215
Buprofezin 759 108 203 583 314 211
Butocarboxim 146 18 70 103 77 35
Butralin 172 29 39 167 70 33
Butylate 370 52 39 214 122 107
Cadusafos 698 106 362 495 98 179
Captafol 221 32 291 200 298 55
Captan (sum) 692 99 386 540 304 211
Carbaryl 754 101 380 576 322 205
Carbendazim and benomyl (sum) 765 108 318 586 297 212
Carbofuran (sum) 697 103 336 556 231 349
Carboxin 696 108 39 499 16 184
Carfentrazone-ethyl (sum) 293 40 210 243 288 54
Chinomethionat 379 71 73 289 156 108
Chlorantraniliprole 766 108 7 578 228 202
Chlorbromuron 163 10 361 92 280 32
Chlordane (sum of cis- and trans-chlordane) 653 104 40 468 280 171
Chlorfenapyr 692 99 140 541 271 205
Chlorfenson 207 42 19 122 39 75
Chlorfenvinphos 690 102 58 487 61 177
Chlorfluazuron 134 15 36 73 75 11
Chloridazon 506 98 380 389 16 151
Chlorobenzilate 374 54 307 220 61 108
Chlorothalonil 772 108 390 587 283 212
Chlorotoluron 706 107 285 494 307 182
Chloroxuron 140 18 397 100 321 35
Chlorpropham 578 81 396 435 18 145
Chlorpyrifos 803 108 311 588 321 212
Chlorpyrifos-methyl 803 108 1 588 215 212
Chlorsulfuron 1 4 318 14 321 10
Chlozolinate 208 42 63 123 123 71
Cinidon-ethyl 370 52 398 214 122 107
Clethodim (sum) 184 30 318 167 314 33
Clofentezine 759 108 1 583 283 211
Clomazone 706 107 393 494 321 182
Clopyralid 1 248
Clothianidin 722 99 206 535 60 189
Coumaphos 653 93 321 443 322 173
Cyanazine 113 10 140 58 32 10
Cyanofenphos 207 42 3 122 61 75
Cyantraniliprole 47 2 328 7 8
Cyazofamid 656 105 53 491 299 186
Cycloate 516 70 71 316 199 142
Cycloxydim (sum) 169 10 394 102 61 34
Cyflufenamid 273 45 186 254 102 37
Cyfluthrin (sum of isomers) 741 102 553 569 299 187
Cymoxanil 765 108 203 586 322 212
Cypermethrin (sum of isomers) 802 108 394 588 321 212
Cyproconazole 754 106 15 576 305 203
Cyprodinil 780 107 388 587 315 211
Cyprosulfamide 5 2
Cyromazine 21 307 70 8 14
Dazomet 58 17 322 17 14 40
DDT 701 108 322 501 290 184
Deltamethrin 803 108 204 588 322 212
Demeton-S-Methyl 367 54 82 219 124 108
Desethyl-Atrazine 552 86 275 385 196 144
Desisopropyl-Atrazine 552 86 214 385 196 144
Desmedipham 402 63 189 257 168 129
Dialifos 207 42 395 122 61 75
Diazinon 773 108 387 588 322 212
Dicamba 146 48 252 97 62 72
Dichlobenil 525 94 63 396 212 145
Dichlofenthion 535 96 320 401 227 145
Dichlofluanid 696 106 336 493 287 183
Dichlormid 338 59 146 276 121 94
Dichlorprop 210 52 74 139 74 82
Dichlorvos 771 108 176 586 322 212
Diclobutrazol 163 10 259 91 32 10
Dicloran 595 81 394 457 215 155
Dicofol (sum of p, p´ and o,p´ isomers) 712 99 615 519 340 213
Dicrotophos 372 62 1 232 135 114
Diethofencarb 765 108 318 586 322 212
Difenoconazole 766 108 141 586 322 212
Diflovidazin (Flufenzin) 204 44 394 127 63 76
Diflubenzuron 765 108 321 586 322 212
Diflufenican 696 108 120 499 290 184
Dimethachlor 700 107 203 491 275 181
Dimethenamid (sum of isomers) 370 52 286 214 122 107
Dimethipin 379 71 394 289 131 108
Dimethoate 765 108 101 586 322 212
Dimethomorph (sum of isomers) 767 108 318 586 322 212
Dimoxystrobin 707 107 393 494 283 182
Diniconazole (sum of isomers) 759 108 140 583 314 211
Dioxacarb 1
Dioxathion 207 42 273 122 61 75
Diphenylamine 591 81 394 439 215 153
Diquat 317 1
Disulfoton (sum) 488 79 255 348 184 133
Ditalimfos 698 106 142 493 288 177
Dithianon 243 30 324 172 105 35
Dithiocarbamates 605 77 320 399 247 176
Diuron 690 108 202 496 282 183
Dodine 423 37 157 335 169 90
Emamectin B1a (free base) 421 52 535 337 171 84
Endosulfan (sum) 772 108 395 588 322 212
Endrin 701 108 322 501 290 184
Endrin Aldehyde 692 108 109 495 290 178
Endrin, Keto- 312 37 394 205 160 74
EPN 769 106 362 535 319 207
Epoxiconazole 766 108 29 586 322 212
epsilon-HCH 48 8 35 48 25 13
EPTC (ethyl dipropylthiocarbamate) 207 42 140 122 61 75
Ethephon 60 46 44 30
Ethiofencarb 119 7 46 68 32 12
Ethiofencarb-Sulfone 119 7 46 68 32 12
Ethiofencarb-Sulfoxide 119 7 392 68 32 12
Ethion 767 103 394 579 318 206
Ethirimol 765 108 388 586 322 210
Ethofumesate 367 54 126 219 124 108
Ethoprophos 699 106 157 495 288 179
Ethoxyquin 222 55 143 164 116 93
Etofenprox 781 99 204 575 301 203
Etoxazole 404 38 148 257 148 74
Etridiazole 208 42 322 123 60 71
Etrimfos 698 106 327 495 288 179
Famoxadone 592 90 393 458 229 171
Fenamidone 759 108 396 583 314 211
Fenamiphos (sum) 566 88 324 450 228 155
Fenarimol 760 102 393 574 303 205
Fenazaquin 759 108 394 583 314 211
Fenbuconazole 763 108 18 584 317 211
Fenbutatin oxide 47 394 27 19 9
Fenchlorphos (sum) 487 92 245 372 217 138
Fenhexamid 765 108 391 586 322 212
Fenitrothion 765 106 140 571 317 193
Fenoxycarb 765 108 1 586 322 212
Fenpicoxamid 15 151 3
Fenpropathrin 771 106 392 582 319 207
Fenpropidin 763 108 392 585 320 212
Fenpropimorph (sum of isomers) 706 90 308 524 256 171
Fenpyrazamine 276 40 394 260 96 34
Fenpyroximate 765 108 396 586 322 212
Fenson (Fenison) 207 42 388 122 61 75
Fensulfothion 649 100 39 458 278 168
Fensulfothion-Oxon 113 7 39 58 32 10
Fensulfothion-Sulfone 113 7 388 58 32 10
Fenthion (sum) 515 83 242 399 221 145
Fenuron 1 4 398 14 18 10
Fenvalerate (sum) 801 108 140 588 322 212
Fipronil (sum) 733 103 390 570 313 204
Flazasulfuron 137 18 316 96 75 33
Flonicamid (sum) 447 78 255 353 176 110
Florasulam 385 80 138 302 151 116
Fluazifop-P 180 52 333 152 73 88
Fluazifop-P-butyl 22 270 46 9 18
Fluazinam 690 105 211 495 281 182
Flubendiamide 580 74 394 468 261 126
Flucythrinate (sum of isomers) 376 73 297 294 133 109
Fludioxonil 766 108 392 586 322 212
Flufenacet 646 105 3 465 261 162
Flufenoxuron 741 108 39 575 305 188
Flumethrin 113 7 243 58 32 10
Flumetralin 6 141 5
Flumioxazine 341 39 377 269 131 67
Fluometuron 513 72 351 322 201 143
Fluopicolide 764 105 268 573 321 210
Fluopyram 615 92 175 475 230 163
Fluoxastrobin 500 58 388 359 210 101
Flupyradifurone 29 3 3
Fluquinconazole 755 104 15 578 305 206
Flurochloridone 597 88 1 376 230 153
Fluroxypyr (sum) 16 11 246 25 38 17
Flusilazole 761 104 354 580 313 207
Flutolanil 503 78 47 332 171 131
Flutriafol 771 104 182 578 313 206
Fluvalinate (sum of isomers) 768 106 783 581 410 249
Fluxapyroxad 421 49 361 296 179 88
Folpet (sum) 684 92 252 522 270 192
Fomesafen 163 10 39 92 61 32
Fonofos 521 77 297 327 210 143
Foramsulfuron 146 18 204 103 77 35
Forchlorfenuron 140 18 292 100 75 35
Formetanate 429 77 322 359 166 128
Formothion 624 92 8 428 243 161
Fosetyl-Al (efozit-Al) 330 24
Fosthiazate 763 108 354 586 201 203
Fuberidazole 308 28 140 195 130 67
Furilazole 207 42 7 122 32 75
Glufosinate 27 11
Glyphosate 82 2 36 27 75 17
Halosulfuron methyl 140 18 138 100 8 35
Haloxyfop 201 52 592 208 353 104
Heptachlor (sum) 653 104 307 471 280 177
Heptenophos 698 106 322 495 143 179
Hexachlorobenzene 701 108 205 501 315 184
Hexachlorocyclohexane, alpha-isomer 700 108 322 501 290 183
Hexachlorocyclohexane, beta-isomer 700 108 495 501 290 183
Hexachlorocyclohexane, delta-isomer 679 100 398 482 276 176
Hexaconazole 775 107 394 581 124 210
Hexaflumuron 394 60 391 245 290 110
Hexazinone 382 54 394 221 322 108
Hexythiazox 765 108 207 586 322 212
Imazalil 765 108 128 586 143 212
Imazamox 353 78 7 278 53 109
Imazapyr 164 40 394 100 321 69
Imazethapyr 6 391 10 2
Imidacloprid 765 108 141 586 315 212
Indoxacarb 775 107 141 581 63 210
Iodosulfuron-methyl 184 27 94 164 288 33
Ioxynil 204 44 389 127 199 76
Ipconazole 516 70 394 317 313 142
Iprodione 765 104 38 578 322 206
Iprovalicarb 765 108 322 586 35 212
Isocarbophos 768 107 204 576 68 208
Isodrin 116 12 312 64 287 15
Isofenphos 698 106 390 495 270 178
Isofenphos-methyl 688 99 90 484 305 176
Isoprocarb 367 54 249 219 284 108
Isoprothiolane 693 108 34 508 178 197
Isoproturon 493 79 210 337 75 133
Isopyrazam 205 18 335 120 124 35
Isoxaben 137 18 56 96 143 33
Isoxadifen-ethyl 431 53 140 301 42 106
Isoxaflutole 376 60 393 239 175 109
Kresoxim-methyl 770 107 398 578 251 209
Lambda-cyhalothrin 802 108 322 588 290 213
Lenacil 696 108 394 499 290 184
Lindane 701 108 380 501 322 184
Linuron 765 108 371 586 276 212
Lufenuron 719 99 383 535 287 180
Malathion (sum) 721 100 383 564 322 199
Mandipropamid 765 108 319 586 70 212
MCPA and MCPB 180 52 138 121 73 81
Mecarbam 688 108 389 493 73 183
Mecoprop (sum) 180 52 169 121 305 81
Mefenpyr-diethyl 172 29 138 167 282 33
Mepanipyrim 764 104 204 575 124 205
Mepiquat 141
Mepronil 367 54 36 219 63 108
Meptyldinocap 204 44 281 127 75 76
Mesosulfuron-methyl 146 18 3 103 62 35
Mesotrione 194 44 391 113 315 76
Metaflumizone (sum of E- and Z- isomers) 548 90 2 395 265 148
Metalaxyl and metalaxyl-M (sum of isomers) 771 104 455 578 373 206
Metaldehyde 163 10 321 92 318 32
Metamitron 696 108 390 499 275 184
Metazachlor 700 107 395 491 302 181
Metconazole (sum of isomers) 688 105 345 498 287 177
Methabenzthiazuron 140 18 305 100 212 35
Methacrifos 616 100 388 461 1 167
Methamidophos 767 103 317 579 290 206
Methidathion 760 102 395 575 321 201
Methiocarb (sum) 598 90 327 455 316 162
Methomyl 766 108 394 586 322 212
Methoxychlor 701 108 356 501 32 184
Methoxyfenozide 765 108 39 586 290 212
Metobromuron 696 108 32 499 92 184
Metolachlor and S-metolachlor (sum of isomers) 705 98 678 496 468 171
Metoxuron 113 10 316 58 322 10
Metrafenone 764 108 113 547 273 211
Metribuzin 695 104 321 487 157 177
Metsulfuron-methyl 332 48 39 270 288 70
Mevinphos 698 106 133 493 77 179
Molinate 516 70 63 317 291 142
Monocrotophos 686 98 203 534 61 195
Monolinuron 163 10 39 92 122 32
Myclobutanil 775 107 362 581 199 210
N,N-Diethyl-m-toluamid (DEET) 652 105 302 462 266 174
Napropamide (sum of isomers) 370 52 243 214 77 107
Nicosulfuron 146 18 167 103 201 35
Nitenpyram 513 72 204 322 90 143
Nitrofen 300 49 203 165 124 84
Novaluron 367 54 294 219 122 108
Nuarimol 370 52 112 214 249 107
o.p'-DDD 631 92 322 434 251 164
o.p'-DDE 631 92 203 434 290 164
Ofurace 370 52 73 214 309 107
Omethoate 728 108 393 575 105 205
Oxadiazon 198 19 394 130 314 53
Oxadixyl 759 108 39 583 322 211
Oxamyl 765 108 1 586 77 212
Oxasulfuron 146 18 247 103 168 35
Oxathiapiprolin 15 284 3 118
Oxycarboxin 163 10 322 92 249 172
Oxydemeton-methyl (sum) 551 83 374 442 216 161
Oxyfluorfen 492 78 294 347 61 32
Paclobutrazol 760 104 389 580 218 140
Paraoxon 526 77 362 324 318 206
Parathion 773 108 391 541 322 212
Parathion-methyl (sum) 768 106 391 580 318 211
Penconazole 772 104 110 578 269 175
Pencycuron 765 108 87 586 315 210
Pendimethalin 775 107 390 581 68 33
Penflufen (sum of isomers) 205 18 303 115 313 206
Penthiopyrad 282 42 203 202 321 212
perchlorate 1 107
Permethrin (sum of isomers) 772 108 242 587 122 142
Pethoxamid 370 52 320 214 199 182
Phenkapton 207 42 245 122 61 75
Phenmedipham 402 63 394 257 168 129
Phenthoate 516 70 5 317 200 143
Phorate (sum) 342 78 41 282 158 115
Phorate (sum) 700 106 8 495 288 179
Phosmet (sum) 595 81 394 438 216 151
Phosphamidon 700 106 358 495 288 179
Phosphane and phosphide salts 1 320 12
Phoxim 513 72 102 323 270 143
Picolinafen 516 70 229 317 282 139
Picoxystrobin 690 108 63 496 244 32
Piperonyl butoxide 163 10 6 92 53 9
Pirimicarb 773 103 394 579 102 212
Pirimicarb, desmethyl- 333 63 140 219 107 110
Pirimiphos-ethyl 654 94 389 476 319 207
Pirimiphos-methyl 769 106 17 582 313 19
Prochloraz (sum) 507 87 54 412 42 18
Procymidone 750 99 388 569 199 205
Profenofos 759 102 348 574 131 178
Profluralin 379 71 255 289 273 133
Promecarb 326 48 245 267 215 138
Prometryn 571 86 394 398 201 212
Propachlor 516 73 337 316 298 184
Propamocarb 715 108 359 586 252 178
Propaquizafop 467 68 203 290 279 107
Propargite 650 96 102 518 122 67
Propazine 370 52 390 214 138 209
Propetamphos 309 28 394 195 307 212
Propham 516 70 210 317 303 108
Propiconazole (sum of isomers) 768 107 276 578 322 141
Propisochlor 547 81 321 387 282 162
Propoxur 690 108 271 496 242 137
Propyzamide 765 108 320 586 192 183
Proquinazid 618 89 63 474 274 32
Prosulfocarb 605 74 309 483 61 180
Prosulfuron 163 10 178 92 291 80
Prothioconazole: prothioconazole-desthio (sum of isomers) 542 90 333 450 296 184
Prothiofos 693 107 102 481 136 67
Pymetrozine 540 74 43 482 61 20
Pyraclostrobin 765 108 164 586 288 78
Pyraflufen-ethyl 135 19 394 111 322 211
Pyrazophos 698 106 393 495 85 211
Pyrethrins 271 47 320 152 313 178
Pyridaben 759 108 100 583 286 6
Pyridalyl 151 13 204 134 143 108
Pyridaphenthion 696 102 207 486 31 109
Pyridate 353 78 391 278 124 210
Pyrifenox 367 54 285 219 315 164
Pyrimethanil 776 107 395 581 277 207
Pyriofenone 273 36 70 201 322 33
Pyriproxyfen 765 108 383 586 78 204
Pyroxsulam 184 27 242 161 301 142
Quinalphos 700 106 117 495 131 179
Quinmerac 503 98 393 388 68 211
Quinoclamine 190 18 300 112 314 170
Quinoxyfen 759 108 304 583 262 175
Quintozene (sum) 658 102 204 466 123 25
Resmethrin (sum of isomers) 366 54 243 216 63 143
Rimsulfuron 69 15 203 75 201 107
Rotenone 513 72 63 322 122 32
Secbumeton 309 28 102 196 138 177
Sedaxane 26 4 3 67
Silthiofam 309 65 196 168
Simazine 370 52 104 214 32 10
Simetryn 113 10 394 91 31 212
Spinetoram (XDE-175) 151 13 394 139 322 212
Spinosad (sum) 765 108 394 586 322 212
Spirodiclofen 765 108 187 586 317 78
Spiromesifen 770 106 38 582 175 39
Spirotetramat (sum) 540 67 344 406 324 142
Spiroxamine (sum of isomers) 775 107 102 581 138 2
Sulfotep 690 102 346 487 31 211
Sulfoxaflor (sum of isomers) 151 13 393 83 224 212
Tau-Fluvalinate 613 81 394 468 314 206
Tebuconazole 774 104 393 580 226 205
Tebufenozide 759 108 391 583 322 147
Tebufenpyrad 766 108 260 586 313 211
Tecnazene 535 96 388 403 314 33
Teflubenzuron 759 108 34 583 303 33
Tefluthrin 760 102 34 574 75 144
Tepraloxydim 137 18 322 96 201 32
Terbacil 516 73 63 320 288 10
Terbufos 698 106 39 494 61 10
Terbufos-sulfone 163 10 39 92 32 182
Terbufos-sulfoxide 113 7 361 1 61 162
Terbumeton 113 10 285 58 273 151
Terbuthylazine 651 98 396 516 237 146
Terbutryn 583 93 291 422 321 210
Tetrachlorvinphos 526 77 316 328 315 212
Tetraconazole 775 107 392 581 279 212
Tetradifon 772 108 252 587 201 178
Tetramethrin 695 102 394 490 321 32
Thiabendazole 765 105 394 585 321 70
Thiacloprid 766 108 40 586 321 212
Thiamethoxam 766 108 113 586 32 180
Thiencarbazone-methyl 128 10 394 61 157 69
Thifensulfuron-methyl 332 48 361 270 322 117
Thiodicarb 765 108 112 586 271 184
Thiofanox 326 48 340 267 180 205
Thiometon 470 74 254 287 270 35
Thiophanate-methyl 684 97 227 501 149 112
Tolclofos-methyl 759 102 307 574 75 48
Tolylfluanid (sum) 445 76 210 345 303 210
Tralkoxydim 140 18 391 100 280 210
Triadimefon 775 107 391 581 85 36
Triadimenol 775 107 39 581 124 35
Tri-allate 367 54 395 219 78 171
Triasulfuron 146 18 39 103 319 212
Triazophos 770 106 306 582 77 182
Tribenuron-methyl 146 18 394 103 267 108
Trichlorfon 518 70 313 319 149 12
Triclopyr 7 112 10 25
Tricyclazole 600 105 318 457 322 211
Trifloxystrobin 765 108 200 586 281 178
Triflumizole 690 105 394 495 132 101
Triflumuron 765 108 191 586 279 143
Trifluralin 694 102 7 506 114 69
Triflusulfuron 15 46 3 42
Triforine 327 50 243 192 200 177
Trimethacarb 326 48 1 267 272 151
Triticonazole 685 101 38 490 76 206
Uniconazole 144 18 279 95 32 182
Valifenalate 119 7 389 68 269
Vamidothion 643 96 33 477 311
Vinclozolin 765 102 319 577 13
Zoxamide 690 122 495
Note: 1: The residue components included in the residue definition defined by various European Commission regulations were measured separately or as their common derivative. The reported residue concentration was calculated from the measured residues.

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Figure 1. Operation characteristic curves indicating the probability of detection of acetamiprid residues when single samples containing 10 apples each are analyzed.
Figure 1. Operation characteristic curves indicating the probability of detection of acetamiprid residues when single samples containing 10 apples each are analyzed.
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Table 1. Summary information on the pesticide residue analyses carried out during 2017-2021.
Table 1. Summary information on the pesticide residue analyses carried out during 2017-2021.
Commodity No. of
Samples2 Analytes3 Tests4 R>MRL5 MRL≥R≥LOQ6 R<LOQ7
All commodities1 9924 622 2,652,560 102 5261 4560
Apples 803 459 227571 1 587 215
Cherries, sour 122 441 32962 1 95 26
Grapes, table 783 459 113132 1 703 79
Peaches/nactarines 468 445 90851 1 350 117
Peppers, green, red 616 459 165388 4 298 314
Strawberries 349 447 60458 3 291 55
Notes: 1: Commodities included in the sampling programme. 2: Number of samples investigated. 3: Number of active substances screened in the samples. All residue components defined by the relevant EC Regulations were inculded in he scope of methods and analysed. The reported results are calculated from the measured residue components. However, it does not mean that all samples were tested for all active subsatnces. 4: Number of tests = number of samples multiplied by the number of residues analyzed. 5: Number of samples contained residues above the MRL. =6: Number of samples contained detectable residues lower than the MRL. 7: Number of samples without detectable residues (limit of quantification).
Table 2. Summary of compliance of exported lots with EU MRLs.
Table 2. Summary of compliance of exported lots with EU MRLs.
Commodity No. of tested No. of lots complied1 No. of lots and proportion of their compliance due to residues detected1
lots AS-s
Apple 1944 50 1545 >92% 9 tau-fluvalinate (89%) 8 folpet (88%) 21 lambda-cyhalothrin (81%)
Cherries 195 21 162 > 96% 23 (dithiocarbamates 87%) 6 thiamethoxam (83%) 4 deltamethrin (50%)
Grape 986 62 869 >90 % 8 buprofezin2 (0%) 4 pyraclostrobin (78%) 36 acetamiprid (86%)
Peach 521 34 465 >95% acetamiprid (87.5%) prochloraz (83.3%) carbendazim (70%)
Peppers, sweet 631 48 460 >90% #3
Strawberry 588 40 444> 90% #4
Notes: The proportion of tested lots that would comply with the indicated probability. 1: There are many cases where the number of measured residues was ≤5. The compliance of these lots cannot be realistically evaluated. Therefore, they are not included in the table. 2: Buprofezin MRL was reduced to 0.01* mg/kg. It was detected in eight lots (0.012-0.066 mg/kg). None of them would comply; Lower compliance was found in case of 16 and 12 lots because of lambda-cyhalothrin (81%), carbendazim (75%), respectively. #3: methomyl, pymetrozine, acetamiprid, clothianidin, spirodiclofen (0%) flonicamid (44%), acetamiprid (69%), tebuconazole (75%), cyflufenamid (80%), lambda-cyhalothrin (81%), spinosad (83%), indoxacarb (84%). #4: emamectin benzoate, cyflufenamid (sum), formetanate (0%), ethirimol (64%), etoxazole (60%), bupirimate (79%), abamectin (75%), spinosad (82%), thiamethoxam (83%), thiacloprid (89%).
Table 3. Summary of samples containing multiple residues.
Table 3. Summary of samples containing multiple residues.
Year No. of samples analyzed Samples w. multiple residues Max. no. of AS No. of samples containing multiple residues1
Apples Cherries, sour Grapes Nectarines Peaches Peppers sweet Strawberries
2017 1902 761 23 75 16 57 45 35 33
2018 1995 820 13 101 16 53 51 44 35
2019 1842 916 15 107 10 49 59 45 36
2020 1750 625 16 89 8 42 39 45 3
2021 1666 719 11 103 9 32 37 43 20
1: The minimum number of active substances in samples was 2 in each commodity and year. The maximum and average number of AS detected in the selected commodities together with the relevant pest and disease groups are shown in Table 4.
Table 4. Number of AS detected in individual samples.
Table 4. Number of AS detected in individual samples.
Commodity Max (average) no. of AS found in one sample Relevant groups of
2017 2018 2019 2020 2021 Diseases Pests
Apples 23 (3.9) 13 (3.9) 8 (3.8) 9 (3.7) 11 (3.5) 3 5
Cherries, sour 8 (3.4) 7 (3.7) 6 (3.6) 6 (3.5) 6 (3.8) 3 5
Grapes, table 12 (4) 11 (4.1) 11(3.8) 11(4.1) 7(3.3) 3 3
Nectarines & peaches 6 (2.7) 7 (3.4) 9 (3.1) 9 (4.1) 5 (2.9) 4 4
Peppers, sweet 10 (3.7) 11 (3.2) 15 (3.8) 15 (3.6) 10 (3.1) 3-4 4
Strawberries 7 (3.4) 9 (4.3) 11 (4.8) 7 (4.3) 9 (5.0) 3 4
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