Assessment of penconazole exposure in winegrowers using urinary biomarkers

Determination of pesticide residues in urine by chromatography-mass spectrometry: methods and applications

Introduction

Pollution has emerged as a significant threat to humanity, necessitating a thorough evaluation of its impacts. As a result, various methods for human biomonitoring have been proposed as vital tools for assessing, managing, and mitigating exposure risks. Among these methods, urine stands out as the most commonly analyzed biological sample and the primary matrix for biomonitoring studies.

Objectives

This review concentrates on exploring the literature concerning residual pesticide determination in urine, utilizing liquid and gas chromatography coupled with mass spectrometry, and its practical applications.

Method

The examination focused on methods developed since 2010. Additionally, applications reported between 2015 and 2022 were thoroughly reviewed, utilizing Web of Science as a primary resource.

Synthesis

Recent advancements in chromatography-mass spectrometry technology have significantly enhanced the development of multi-residue methods. These determinations are now capable of simultaneously detecting numerous pesticide residues from various chemical and use classes. Furthermore, these methods encompass analytes from a variety of environmental contaminants, offering a comprehensive approach to biomonitoring. These methodologies have been employed across diverse perspectives, including toxicological studies, assessing pesticide exposure in the general population, occupational exposure among farmers, pest control workers, horticulturists, and florists, as well as investigating consequences during pregnancy and childhood, neurodevelopmental impacts, and reproductive disorders.

Future directions

Such strategies were essential in examining the health risks associated with exposure to complex mixtures, including pesticides and other relevant compounds, thereby painting a broader and more accurate picture of human exposure. Moreover, the implementation of integrated strategies, involving international research initiatives and biomonitoring programs, is crucial to optimize resource utilization, enhancing efficiency in health risk assessment.

Hexaconazole exposure may lead to Parkinson via disrupting glucocerebrosidase and parkin: molecular interaction, dynamics, MMPBSA and DFT based in-silico predictive toxicology

Hexaconazole is a known fungicide for agricultural purposes. It has bioaccumulation ability which makes it important for its toxicological characterization. There are various neurological impacts of pollutants on human health. Therefore, in this study, we have done predictive analyses of the interaction mechanism of hexaconazole by molecular interaction analysis, molecular dynamics simulation, and Poisson-Boltzmann surface area (MM-PBSA) to assess hexaconazole's potency to disrupt the homeostasis of glucocerebrosidase (-7.9 kcal/mol) and parkin (-5.67 kcal/mol) proteins which have significant roles in the manifestation of Parkinson disease. The findings reveal that hexaconazole has the potency to form stable interactions with glucocerebrosidase and parkin. This research provides a molecular and atomic-level understanding of how hexaconazole exposure may disrupt the homeostasis of glucocerebrosidase and parkin. The root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration, and hydrogen bonding exhibited the potent molecular interactions of hexaconazole, which may lead to neurological manifestations such as Parkinson disease.

Fungicides as a risk factor for the development of neurological diseases and disorders in humans: a systematic review

Although studies show that pesticides, especially insecticides, may be toxic to humans, publications on the neurological effects of fungicides are scarce. As fungicides are used widely in Brazil, it is necessary to gather evidence to support actions aimed at safely using of these chemicals. We investigated through a systematic review of publications on the use of fungicides and consequences of exposure related to nervous system diseases or neurological disorders in humans. The protocol review was registered on PROSPERO and followed the guidelines of the PRISMA-Statement. As far as it is known, there is no apparent systematic review in the literature on this topic. The search was comprised of the following databases: PubMed; Web of Science; Scopus and EMBASE, using groups of Mesh terms and strategies specific to each database. Thirteen articles were selected for this review. Regarding the substances analyzed in the studies, some reported the use of fungicides in general, without separating them by type, while others summarized the categories of all pesticides by their function (insecticides, herbicides, fungicides, etc.) or chemical class (dithiocarbamate, dicarboximide, inorganic, etc.). However, most of the articles referred to fungicides that contain the metal manganese (Mn) in their composition. As for neurological disorders, articles addressed Parkinson's disease (PD), neurodevelopmental outcomes, extrapyramidal syndrome resembling PD, cognitive disorders, depression, neural tube defects, motor neurone disease, and amyotrophic lateral sclerosis. Most investigations pointed to exposure to fungicides, mainly maneb and mancozeb, leading to the development of at least one neurological disease, which suggests the need for further multicentric clinical trials and prospective studies for greater clarity of the research problem.

Non-target biotransformation enzymes as a target for triazole-zinc mixtures

Triazoles inhibit lanosterol 14α-demethylase and block ergosterol biosynthesis in fungal pathogens. However, they also interact with other cytochrome P450 enzymes and influence non-target metabolic pathways. Disturbingly, triazoles may interact with essential elements. The interaction of penconazole (Pen), cyproconazole (Cyp) and tebuconazole (Teb) with Zn2+ results in the formation of deprotonated ligands in their complexes or in the creation of complexes with Cl- as a counterion or doubly charged complexes. Triazoles, as well as their equimolar cocktails with Zn2+ (10-6 mol/L), decreased the activities of the non-target enzymes CYP19A1 and CYP3A4. Pen most decreased CYP19A1 activity and was best bound to its active centre to block the catalytic cycle in computational analysis. For CYP3A4, Teb was found to be the most effective inhibitor by both, activity assay and interaction with the active centre. Teb/Cyp/Zn2+ and Teb/Pen/Cyp/Zn2+ cocktails also decreased the CYP19A1 activity, which was in correlation with the formation of numerous triazole-Zn2+ complexes.

Resveratrol ameliorates penconazole-induced cardiotoxicity by inhibition of oxidative stress and apoptosis in zebrafish larvae

Penconazole (PEN) is a typical systemic triazole fungicide with cardiac toxic effects. Resveratrol (RES) is a natural polyphenolic phytochemical with antioxidation properties. This study aimed to investigate if RES could protect against PEN-induced cardiotoxicity and to determine the underlying mechanisms. Zebrafish embryos were exposed to 0, 0.5, 1 and 2 mg/L of PEN from 4 to 96 h post fertilization (hpf) and cardiac developmental toxicity was assessed. Our results showed that PEN decreased hatching rate, survival rate, heart rate and body length, with increased malformation rate and spontaneous movement. PEN induced pericardial edema and abnormal cardiac structure in myl7:egfp transgenic zebrafish, as well as downregulation of cardiac development related genes (nkx2.5, tbx2.5, gata4, noto, and vmhc). In addition, PEN elevated oxidative stress via reactive oxygen species (ROS) accumulation and triggered cardiomyocytic apoptosis by upregulation of p53, bcl-2, bax and caspase 3. These adverse outcomes were counteracted by RES, indicating that RES ameliorated PEN-induced cardiotoxicity by inhibiting oxidative stress and apoptosis in zebrafish. Taken together, this study revealed the important role of oxidative stress in PEN-induced cardiotoxicity and identified dietary RES supplementation as a novel strategy to mitigate its toxicity.

Enantioselective toxicity effect and mechanism of hexaconazole enantiomers to human breast cancer cells

The toxicity effects of chiral pesticides on living organisms have attracted an increasing public attention. This study aims to investigate the toxicity effect and mechanism of hexaconazole (HEX) to human breast cancer cell (MCF-7) at enantiomer levels. HEX exposure obviously inhibited cells activities in a dose-dependent manner. Under the conditions of VIP >1 and p < 0.05, a total of 255 and 177 differential metabolites (DMs), 17 and 15 amino acid- and lipid-related metabolic pathways were disturbed after (+)-HEX and (-)-HEX exposure, respectively. HEX exposure may affect cell membrane function, signal transduction, and cell differentiation. We further investigated the mechanism of enantioselective differences by using molecular docking which showed that CYP17A1 was the main enzyme that leading to endocrine disrupting effects with the binding energy of -6.30 and -6.08 kcal/mol compared to CYP19A1 enzyme which were -5.81 and -5.93 kcal/mol for (+)-HEX and (-)-HEX, respectively. The docking results explained the reasons why (+)-HEX achieved higher cytotoxicity and induced more seriously metabolic profiles than its antipode. These findings could provide a new insight to understand the enantioselective cytotoxicity effect and mechanism of HEX and will be conducive to assessing its risk to human health at enantiomer levels.

High contamination of a sentinel vertebrate species by azoles in vineyards: a study of common blackbirds (Turdus merula) in multiple habitats in western France

Azoles represent the most used family of organic fungicides worldwide and they are used in agriculture to circumvent the detrimental impact of fungi on yields. Although it is known that these triazoles can contaminate the air, the soil, and the water, field data are currently and dramatically lacking to assess if, and to what extent, the use of triazoles could contaminate non-target wild vertebrate species, notably in agroecosystems. In this study, we aimed to document for the first time the degree of blood contamination of a generalist wild bird species by multiple azoles which are used for plant protection and fungi pest control in various habitats. We deployed passive air samplers and captured 118 Common blackbirds (Turdus merula) in an agroecosystem (vineyard), a protected forest, and a city in western France. We collected blood and analyzed the plasma levels of 13 triazoles and 2 imidazoles. We found that a significant percentage of blackbirds living in vineyards have extremely high plasma levels of multiple azoles (means (pg.g^-1); tebuconazole: 149.23, difenoconazole: 44.27, fenbuconazole: 239.38, tetraconazole: 1194.16), while contamination was very limited in the blackbirds from the protected forest and absent in urban blackbirds. Interestingly, we also report that the contamination of blackbirds living in vineyard was especially high at the end of Spring and the beginning of Summer and this matches perfectly with the results from the passive air samplers (i.e., high levels of azoles in the air of vineyards during June and July). However, we did not find any correlation between the levels of plasma contamination by azoles and two simple integrative biomarkers of health (feather density and body condition) in this sentinel species. Future experimental studies are now needed to assess the potential sub-lethal effects of such levels of contamination on the physiology of non-target vertebrate species.

Analytical and toxicological aspects of dithiocarbamates: an overview of the last 10 years

Compilation studies related to toxicological aspects and also biological monitoring and analysis methods for specific fungicides and, mainly, those that belong to the class of the dithiocarbamates (DTCs) have not been carried out at least in the last ten years. DTCs - dimethyldithiocarbamates, ethylenebisditiocarbamates, propylenebisditiocarbamates - are organosulfur compounds that form complexes due to the presence of different chemical elements, which bind strongly and inhibit enzymes that are essential to the functioning of the organism, causing a serious proven adverse effect on biological systems, such as alteration of thyroid hormones, teratogenesis and neurotoxicity. It is still evident, as shown by world data, that the growing consumption of fungicides has increasingly exposed the population in general and, in particular, workers who deal with these substances. There is a scarcity of studies in the literature discussing the toxicological and analytical aspects that are important for understanding the real effects of DTCs and monitoring human exposure to them. Therefore, the aim of this work was to expose, in a comprehensive way and through a narrative review, the negligence of research related to the fungicides of the DTCs class, their metabolites, as well as the toxicological and analytical aspects involved. The review is divided into two parts: (1) Toxicological aspects, including toxicokinetics, toxicodynamics and toxidromes; and (2) Analytical Toxicology, which comprises biomarkers, sample preparation and identification/quantification methods.

A Critical Scoping Review of Pesticide Exposure Biomonitoring Studies in Overhead Cultures

The exposure of operators, workers, residents and bystanders to pesticides is of high potential concern. Yet, reports on pesticide residues in the environment and near treated fields often spark debates if such findings might indicate a health risk. Although the underlying models are considered conservative, there are only limited field data on systemic exposure available. As a first step to improve the situation, we conducted a scoping review of state-of-the-art pesticide exposure biomonitoring studies in operators, workers, residents or bystanders. In contrast to existing reviews, we focused on target cultures of potential high pesticide exposure such as tree-grown produce, vine or hops. The search was conducted in Web of Science, Scopus and PubMed. Out of 17 eligible articles, a total of 11 studies met our search criteria, and 6 of them quantified the systemic exposure of humans. The analysis revealed that exposure was mainly driven by application of pesticides and reentry work, resulting in a higher exposure of operators and workers than of residents and bystanders. In nearly all cases, the systemic exposure was below the relevant toxicological reference values. The studies were subsequently analyzed to identify key criteria for a reliable design of a biomonitoring study on pesticide exposure.

Gold-based lateral-flow strip for the detection of penconazole in watermelon and cucumber samples

As a typical triazole fungicide, penconazole (PEN) is widely used in agriculture but has been proven to be toxic. In this study, we designed a new hapten to prepare a highly sensitive and specific anti-PEN monoclonal antibody (mAb) and established a gold nanoparticle-based lateral-flow immunoassay (LFIA) for the detection of PEN residues in watermelon and cucumber. The 50% inhibitory concentration (IC50) of the mAb was 0.42 ng/mL and the LFIA strip had a visual limit of detection (vLOD) of 2.5 ng/g and a cut-off value of 10 ng/g in watermelon and cucumbers. The calculated limit of detection (LOD) of the LFIA strip was 0.36 ng/g for watermelon and 0.29 ng/g for cucumber. The LFIA strip also gave a recovery rate of 92.5–109.0% for watermelon samples and 92.5–106.7% for cucumber samples. These results using the LFIA strip are highly consistent with those seen using LC-MS/MS. Thus our developed LFIA strip represents a potentially reliable tool for the rapid on-site screening for PEN in watermelons and cucumbers..

Cumulative risk assessment of dietary exposure to triazole fungicides from 13 daily-consumed foods in China

The agroeconomic benefits of the routine use of triazole fungicides on crops have been evident for more than 40 years. However, increasing evidence shows that residues of triazoles are ubiquitous in various foods and thus could pose a potential health risk to humans. We analyzed 3406 samples of 13 food commodities that were collected from markets in 9 regions across China, and assessed the health risk of both chronic and acute exposure to the triazoles for Chinese children (1-6 years old) and the general population. Among all samples, 55.52% had triazoles in concentrations of 0.10-803.30 μg/kg, and 29.77% of samples contained a combination of 2-7 triazoles. Tebuconazole and difenoconazole were the most commonly found triazoles in the foods, being detected in 33.44% and 30.45% of samples, respectively. Chronic and acute cumulative risk assessment for total triazoles based on a relative potency factor method revealed that exposure to triazoles from these particular commodities was below the levels that might pose a health risk (chronic hazard index range, 5.90×10^-7 to 1.83×10^-3; acute hazard index range, 7.77×10^-5 to 0.39, below 1). Notably, dietary exposure risk for children was greater than that for the general population-particularly for the acute intake of mandarin, grape, and cucumber (acute hazard index values of 0.35-0.39). Despite the low health risk, the potential hazards of exposure to triazoles should raise public concern owing to their ubiquitous presence in common foods and potential cumulative effects.

Tebuconazole induces liver injury coupled with ROS-mediated hepatic metabolism disorder

Tebuconazole, the most widely used fungicide, is reported to cause various environmental problems and have serious health risks in humans. Despite numerous advances in toxicity studies, its internal metabolic process and the underlying mechanisms have not been systemically studied. The present study administered low doses (0.02 g/kg bw and 0.06 g/kg bw) of tebuconazole to C57BL/6 mice in vivo. The high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed and validated to analyze the tebuconazole in different organs, and our data revealed that tebuconazole mainly accumulated in the liver and that histopathological damage were exhibited in this organ. Tebuconazole significantly dysregulated phase Ⅰ- and phase II-metabolizing enzymes, ATP-binding cassette (ABC) efflux transporters (Abcc2 and Abcc3) and fatty acid metabolism-related genes (Cdkn1a and Fasn), thereby directly causing liver hypertrophy and steatosis. Importantly, the excessive induction of reactive oxygen species (ROS) and oxidative stress partially accounted for the metabolic abnormalities mediated by tebuconazole. Moreover, these alterations were related to the abnormal transcriptional levels of peroxisome proliferator-activated receptor α (PPAR-α) and liver x receptor α (LXR-α), which were predicted to bind to tebuconazole via hydrogen bonding interactions. The current findings provide new insight into the molecular mechanisms of metabolic abnormalities induced by tebuconazole at low concentration, and are conducive to a better understanding of the environmental risk posed by this fungicide.

Effects of penconazole enantiomers exposure on hormonal disruption in zebrafish Danio rerio (Hamilton, 1822)

PEN is a widely used triazole fungicide, usually used to control grape white rot. In the process of agricultural use, PEN will be scattered to the soil and water environment, which brings certain environmental safety risks. In this study, we used a 200-μg/L solution of Rac-PEN, (+)-PEN, and (-)-PEN to perform a 28-day exposure test on zebrafish. The results showed that long-term low-dose PEN exposure did not significantly change the growth factor K and the number of spawning of zebrafish. However, the content of four important hormones vitellogenin, 17β-estradiol, testosterone, and 11-ketotestosterone in zebrafish has changed significantly. Furthermore, we measured the expression of hypothalamus-pituitary-gonads-liver (HPGL) axis-related genes, and the results showed that the expressions of related genes in the brain, gonads, and liver all changed significantly. Combining the above results, we can conclude that PEN has obvious endocrine disrupting effect on zebrafish, and has gender-specific endocrine effects. Meanwhile, Rac-PEN and (+)-PEN had stronger effects on the endocrine system of zebrafish than (-)-PEN.

Romain SJ, Pedersen EI, Siddiqui S, Chappell PE, White JW, Armbrust KL, Brander SM. Salinity Alters Toxicity of Commonly Used Pesticides in a Model Euryhaline Fish Species (Menidia beryllina)

Changing salinity in estuaries due to sea level rise and altered rainfall patterns, as a result of climate change, has the potential to influence the interactions of aquatic pollutants as well as to alter their toxicity. From a chemical property point of view, ionic concentration can increase the octanol–water partition coefficient and thus decrease the water solubility of a compound. Biologically, organism physiology and enzyme metabolism are also altered at different salinities with implications for drug metabolism and toxic effects. This highlights the need to understand the influence of salinity on pesticide toxicity when assessing risk to estuarine and marine fishes, particularly considering that climate change is predicted to alter salinity regimes globally and many risk assessments and regulatory decisions are made using freshwater studies. Therefore, we exposed the Inland Silverside (Menidia beryllina) at an early life stage to seven commonly used pesticides at two salinities relevant to estuarine waters (5 PSU and 15 PSU). Triadimefon was the only compound to show a statistically significant increase in toxicity at the 15 PSU LC₅₀. However, all compounds showed a decrease in LC₅₀ values at the higher salinity, and all but one showed a decrease in the LC₁₀ value. Many organisms rely on estuaries as nurseries and increased toxicity at higher salinities may mean that organisms in critical life stages of development are at risk of experiencing adverse, toxic effects. The differences in toxicity demonstrated here have important implications for organisms living within estuarine and marine ecosystems in the Anthropocene as climate change alters estuarine salinity regimes globally.

Developmental toxicity and neurotoxicity of penconazole enantiomers exposure on zebrafish (Danio rerio)

Penconazole is a widely used chiral triazole bactericide that may adversely affect the environment. It contains two corresponding enantiomers and there may be differences in toxicity between the isomers. Therefore, in this study, we exposed zebrafish embryos to different concentrations of the penconazole enantiomer to study the developmental toxicity and neurotoxicity of penconazole on zebrafish and the difference in toxicity between enantiomers. The results showed that penconazole exposure caused adverse effects on zebrafish embryos, such as autonomous motor abnormalities, heart rate slowing, and increased deformity, resulting in significant developmental toxicity. Meanwhile, also caused the zebrafish larvae to slow movement, the neurotransmitter content and nervous system related gene expression significantly changed, which proved that penconazole also caused neurotoxicity to zebrafish. Interestingly, our results also clearly show that (+)-penconazole is significantly more toxic to zebrafish than (-)-penconazole at the same concentration, whether it is developmental toxicity or neurotoxicity, which suggests that we should focus on (+)-penconazole more when conducting toxicological studies on penconazole.

Bioaccumulation and toxic effects of penconazole in earthworms (Eisenia fetida) following soil exposure

As an agricultural fungicide, penconazole (PEN) is widely used and has adverse effects on various organisms. In order to evaluate the ecological safety risks of PEN, the bioaccumulation and toxic effects of PEN in earthworms were studied. Specifically, the results show that the biota-sediment accumulation factor (BSAF) of PEN in earthworms reaches its maximum within 1 day, and then decreases slowly. It reached its lowest value after 14 days of PEN exposure and then rose again. In addition, oxidative stress and metabolic disorder of the earthworm with PEN exposure were assessed. After PEN exposure, the related indicators of oxidative stress involved in the activities of SOD and CAT and the contents of GSH and MDA all changed significantly in earthworms. Moreover, metabolomics analysis of earthworms showed disturbed metabolic profiles following PEN exposure. Respectively, PEN exposure significantly altered the relative abundances of 14 metabolites in earthworms. In general, exposure to PEN caused oxidative stress and metabolic profile disorders of earthworms. The results of this study will be helpful for further evaluation of soil ecological security of PEN.

Acute exposure to the fungicide penconazole affects some biochemical parameters in the crayfish (Astacus leptodactylus Eschscholtz, 1823)

Penconazole is one of the most widely used fungicides all over the world, and since it spreads to large environments, its toxic effects on non-target organisms are of great concern. The toxic effects of penconazole on crayfish (Astacus leptodactylus), which is a bioindicator in freshwater ecosystems and consumed economically, are not known. Therefore, in this study, the purpose was to contribute to the literature on the potential harmful effects of penconazole on a non-target species, Astacus leptodactylus. For this aim, the acute toxicity (96 h) of penconazole was examined. The 96-h LC₅₀ value of penconazole was detected as 18.7 mg L^-1. Four concentrations of penconazole (18.7 mg L^-1, 9.35 mg L^-1, 4.68 mg L^-1, 2.34 mg L^-1) were applied to crayfish for 96 h. The results showed that penconazole had destructive effects on esterase mechanisms by inhibiting acetylcholinesterase (AChE) and carboxylesterase (CaE) activities. Significant increases were observed in all antioxidant parameters (superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), reduced glutathione (GSH), malondialdehyde (MDA)) in all doses except the lowest concentration (2.34 mg L^-1). All adenosine triphosphatase (ATPase) activities (Na⁺/K⁺-ATPase, Mg²⁺-ATPase, Ca²⁺-ATPase, total ATPase) had significant dose-related inhibition in both gill and muscle tissues. In summary, our findings show that acute penconazole administration to crayfish causes significant toxic effects on esterase, antioxidative parameters, and metabolic enzymes.

Wastewater-based epidemiology approach to assess population exposure to pesticides: a review of a pesticide pharmacokinetic dataset

Wastewater-based epidemiology is an innovative approach to estimate a population's intentional and unintentional consumption of chemicals based on biomarker assays found in wastewater. This method can provide real-time objective information on the xenobiotics to which a population is directly or indirectly exposed. This approach has already been used to assess the population exposure to four classes of pesticides: organochlorines (chlordecone), triazines, organophosphates, and pyrethroids. This review aims to obtain the data (excretion rates) and characteristics (pesticide and metabolites stability, including in-sewer one) for other pesticides to broaden the scope of this new method. Excretion rates and stability descriptions for 14 pesticides, namely 2,4-D, aldrin, carbaryl, chlorobenzilate, dieldrin, diquat, ethion, glufosinate, glyphosate, folpet, malathion, parathion, penconazole, and tebuconazole, will be discussed in a practical framework.

Impacts of Penconazole and Its Enantiomers Exposure on Gut Microbiota and Metabolic Profiles in Mice

Exposure to chiral pesticides poses many potential health risks. In this study, we examined the impacts of exposure to penconazole and its enantiomers on gut microbiota and metabolic profiles in mice. The relative abundance of microbiota in cecal content significantly changed following exposure to penconazole and its enantiomers. At the genus level, the relative abundances of seven gut microflora were altered following exposure to (-)-penconazole. Both (±)-penconazole and (+)-penconazole caused significant changes in the relative abundances of five gut microflora. In addition, targeted serum metabolomics analysis showed disturbed metabolic profiles following exposure. Respectively, (±)-penconazole, (+)-penconazole, and (-)-penconazole exposure significantly altered the relative levels of 29, 23, and 36 metabolites. In general, exposure to penconazole and its enantiomers caused disorders in gut microbiota and metabolic profiles of mice. The potential health risks of penconazole and its enantiomers now require further evaluation.

Methods for the Identification of Outliers and Their Influence on Exposure Assessment in Agricultural Pesticide Applicators: A Proposed Approach and Validation Using Biological Monitoring

The “patch” approach for skin exposure assessment can easily be combined with biological monitoring in real-life pesticide studies. Nevertheless, this approach is sensitive to outliers, with values markedly deviating from other members of the sample, which can result in a gross overestimation of exposure. This study aimed at developing methods for outlier identification and validating them while using biological monitoring. Twenty-seven workers applying mancozeb in Italian vineyards participated in this study. Their skin exposure was estimated while using the patch methodology, while ethylene-thiourea (ETU) was measured in the 24-h post-exposure urine as a biomarker of exposure. The outliers were detected using methods that were based on the multiplication of the median, the median absolute deviation, and boxplots. The detection rate varied between 2.3% and 17.3%. The estimated median skin exposure of 3.2 μg was reduced to 1.2 μg when the modified Z score was used. The highest reduction in the skin exposure was above 54 μg. The use of the modified Z score for outlier detection resulted in an increase in the correlation coefficient between the skin exposure and the urine ETU levels from 0.46 to 0.71, which suggested the validity of the approach. Future studies should standardize and improve the methods for pesticide exposure and risk assessment.