Determination of 5-hydroxythiabendazole in human urine as a biomarker of exposure to thiabendazole using LC/MS/MS

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.

The ABCG2 protein in vitro transports the xenobiotic thiabendazole and increases the appearance of its residues in milk

Thiabendazole (TBZ) is a broad-spectrum anthelmintic and fungicide used in humans, animals, and agricultural commodities. TBZ residues are present in crops and animal products, including milk, posing a risk to food safety and public health. ABCG2 is a membrane transporter which affects bioavailability and milk secretion of xenobiotics. Therefore, the aim of this work was to characterize the role of ABCG2 in the in vitro transport and secretion into milk of 5-hydroxythiabendazole (5OH-TBZ), the main TBZ metabolite. Using MDCK-II polarized cells transduced with several species variants of ABCG2, we first demonstrated that 5OH-TBZ is efficiently in vitro transported by ABCG2. Subsequently, using Abcg2 knockout mice, we demonstrated that 5OH-TBZ secretion into milk was affected by Abcg2, with a more than 2-fold higher milk concentration and milk to plasma ratio in wild-type mice compared to their Abcg2-/- counterpart.

Co-detection of azoxystrobin and thiabendazole fungicides in mold and mildew resistant wallboards and in children

The study measured the levels of azoxystrobin (AZ) and thiabendazole (TBZ) in wallboards and metabolite levels of these fungicides in children. The paper covering of wallboard samples contained a higher concentration of AZ and TBZ than the gypsum core, and similar amounts (w/w) of these two fungicides were present in the samples. These data suggest that commercial products containing a 1:1 (w/w) amount of AZ and TBZ, such as Sporgard® WB or Azo Tech™, were applied to the wallboard paper. This is the first detection of TBZ in mold-and-mildew resistant wallboards. The TBZ metabolite, 5OH-TBZ, was detected in 48% of urine samples collected from children aged 40-84 months, and was co-detected with AZ-acid, a common AZ metabolite, in 37.5% of the urine samples. The detection frequency of 5OH-TBZ was positively associated with the detection frequency of AZ-acid. These findings suggest that certain types of wallboards used in homes and commercial buildings may be a potential source of co-exposure to AZ and TBZ in humans.

Simultaneous Determination of Adulterants in Dietary Food Supplements Using Multivariate Data Analysis after Preconcentration with Novel Nanosorbents and Chromatographic Measurement

Background

The increasing popularity of dietary supplements and, consequently, related adulteration emphasizes the rising need to examine the association of food supplements with fraud. Intentional or unintentional fraud in food supplements by hazardous chemicals compounds is a problem that many countries are struggling with. Much effort have been made to effectively and reliably control the quality of food supplements.

Objective

Due to the importance of the subject, an analytical method for the simultaneous and reliable detection and quantitative determination of three key adulterants in dietary food supplements was developed. The proposed method benefits from analytical methods and multivariate calibration methods to progress the determination of adulterants in a complex matrix.

Methods

HPLC assisted by multivariate curve resolution-alternating least square (MCR-ALS) analysis was used to detect adulterants in real samples after separation and preconcentration using novel mesoporous carbon nanoparticles. Solid-phase extraction (SPE) optimization was accomplished by central composite design (CCD). In order to obtain the best results, the MCR-ALS model was compared with the parallel factor analysis 2 (PARAFAC2) model and validated by estimation of linearity, detection limits, and recovery.

Results

The detection limits and linear dynamics were calculated as 1.5, 4.27, and 4.77 µg/mL, and 1–50, 5–20, and 5–20 µg/mL for caffeine, ephedrine, and fluoxetine, respectively. Mean recovery for determination of caffeine, ephedrine, and fluoxetine using the developed method was reported as 101.75, 91.7, and 92.36, respectively.

Conclusion

The results showed that to avoid negative health outcomes associated with the excessive consumption of adulterated food supplements releasing such products should be carefully regulated. The developed method was validated using statistical factors and showed acceptable and reliable results.

Highlights

(1) The application of MCR-ALS coupled with HPLC-Diode-Array Detection data sets allowed the simultaneous identification and quantification of three key adulterants (caffeine, ephedrine, and fluoxetine) in dietary food supplements. (2) A small amount of the novel adsorbent was successfully used to preconcentrate the trace amounts of adulterants in samples. (3) This method benefits from the chemometrics tools and experimental design to significantly reduce the use of toxic solvents and complicated instruments to propose a less time-consuming method for quantification of multicomponents in the presence of uncalibrated interferents.

Exposure to common-use pesticides, manganese, lead, and thyroid function among pregnant women from the Infants' Environmental Health (ISA) study, Costa Rica

BACKGROUND

Pesticides and metals may disrupt thyroid function, which is key to fetal brain development.

OBJECTIVES

To evaluate if current-use pesticide exposures, lead and excess manganese alter free thyroxine (FT4), free triiodothyronine (FT3), and thyroid stimulating hormone (TSH) concentrations in pregnant women from the Infants' Environmental Health Study (ISA).

METHODS

At enrollment, we determined women's (n = 400) specific-gravity corrected urinary pesticide (μg/L) metabolite concentrations of mancozeb (ethylene thiourea (ETU)), pyrimethanil, thiabendazole, chlorpyrifos, synthetic pyrethroids, and 2,4-D. We also measured manganese hair (MnH) (μg/g) and blood (MnB) (μg/L), and blood lead (PbB) (μg/L) concentrations. To detect an immediate and late effect on thyroid homeostasis, we determined TSH, FT4 and FT3 in serum obtained at the same visit (n = 400), and about ten weeks afterwards (n = 245). We assessed associations between exposures and outcomes with linear regression and general additive models, Bayesian multivariate linear regression, and Bayesian kernel machine regression.

RESULTS

About 80%, 94%, and 100% of the women had TSH, FT4, and FT3 within clinical reference ranges, respectively. Women with higher urinary ETU, and pyrimethanil-metabolites, had lower FT4: β = -0.79 (95%CI = -1.51, -0.08) and β = -0.29 (95%CI = -0.62, -0.03), respectively, for each tenfold increase in exposure. MnB was positively associated with FT4 (β = 0.04 (95%CI = 0.00, 0.07 per 1 μg/L increase), and women with high urinary pyrethroid-metabolite concentrations had decreased TSH (non-linear effects). For the late-effect analysis, metabolites of pyrethroids and chlorpyrifos, as well as MnH, and PbB were associated decreased TSH, or increased FT4 and/or FT3.

DISCUSSION

Mancozeb (ETU) and pyrimethanil may inhibit FT4 secretion (hypothyroidism-like effect), while chlorpyrifos, pyrethroids, MnB, MnH, PbB and Mn showed hyperthyroidism-like effects. Some effects on thyroid homeostasis seemed to be immediate (mancozeb (ETU), pyrimethanil, MnB), others delayed (chlorpyrifos, MnH, PbB), or both (pyrethroids), possibly reflecting different mechanisms of action.

Electrochemical determination of thiabendazole pesticide extracted and preconcentrated from tomato samples by cloud point extraction

A procedure for electroanalytical determination of the fungicide TBZ extracted and preconcentrated from tomatoes by the cloud-point extraction (CPE) technique was developed and validated in this work. The analytical technique used for this determination was HPLC coupled to an electrochemical detector (HPLC/EC), with a BDD electrode. The main variables of the CPE process were evaluated using a 24 full factorial design. The optimal condition of CPE was achieved by using Tergitol (19% v/v), NaCl (0.83 g), ultrasonic stirring time of 15 min and a temperature of 36 °C. Under these conditions, the preconcentration factor obtained was 5.7. The limits of detection (LOD) and quantification (LOQ) were 2.7 × 10-8 mol L-1 (or 5.4 μg L-1) and 5.5 × 10-8 mol L-1 (or 11 μg L-1), respectively. The average recovery values varied from 80.7% to 115.1% and the precision (average of 3 days) was less than 15%, indicating the good accuracy and precision of the method developed here. Upon applying the method to examine commercial tomatoes, TBZ was detected in one of the three analyzed samples.

Concentrations and temporal trends in pesticide biomarkers in urine of Swedish adolescents, 2000-2017

Agricultural pesticides are extensively used for weed- and pest control, resulting in residues of these compounds in food. The general population is mainly exposed through dietary intake. Exposure to certain pesticides has been associated with adverse human health outcomes. Our aim was to assess urinary concentrations and temporal trends in the biomarkers of commonly used pesticides. Samples were collected from adolescents (n = 1060) in Scania, Sweden, from 2000 to 2017. Concentrations of 14 pesticide biomarkers were analyzed in urine using LC-MS/MS. Temporal trends in biomarker concentrations (ln-transformed) were evaluated using linear regression. Biomarkers of pyrethroids (3-PBA and DCCA), chlorpyrifos (TCPy), chlormequat (CCC), thiabendazole (OH-TBZ), and mancozeb (ETU) were detected in >90% of the population all sampling years. The biomarkers CCC and TCPy had the highest median concentrations (>0.8 µg/L), whereas the biomarkers of cyfluthrin (4F-3-PBA) and two pyrethroids (CFCA) had the lowest median concentrations (<0.02 µg/L). Increasing temporal trends were found for the biomarkers 3-PBA (3.7%/year), TCPy (1.7%/year) and biomarkers of pyrimethanil (11.9%/year) and tebuconazole (12.2%/year). Decreasing trends were found for CCC (-5.5%/year), OH-TBZ (-5.5%/year), and ETU (-3.9%/year). Our results suggest that Swedish adolescents are commonly exposed to pesticides in low concentrations (median concentrations <3.88 µg/L).

Pesticide exposure among Bolivian farmers: associations between worker protection and exposure biomarkers

The use of pesticides has increased during the past decades, also increasing the risk of exposure to toxic pesticides that can cause detrimental health effects in the future. This is of special concern among farmers in low-to-middle-income countries that may lack proper training in the safe use of these chemicals. To assess the situation in Bolivia a cross-sectional study in three agricultural communities was performed (n = 297). Handling, use of personal protective equipment (PPE) and pesticide exposure were assessed by a questionnaire and measurements of urinary pesticide metabolites (UPMs). Results showed that methamidophos (65%) and paraquat (52%) were the most commonly used pesticides and that 75% of the farmers combined several pesticides while spraying. Notably, only 17% of the farmers used recommended PPEs while 84% reported to have experienced symptoms of acute pesticide poisoning after spraying. UPM measurements indicated high levels of exposure to chlorpyrifos, pyrethroids and 2,4D and that men generally were more highly exposed compared to women. Our study demonstrates that farmers who are better at following recommendations for pesticide handling and use of PPE had a significantly lower risk of having high UPM levels of most measured pesticides. Our results thus confirm the need of proper training of farmers in low-to-middle-income countries in proper protection and pesticide handling in order to reduce exposure levels and health problems.

Prenatal pesticide exposure and respiratory health outcomes in the first year of life: Results from the infants' Environmental Health (ISA) study

BACKGROUND

Growing evidence suggests that pesticide exposure may influence respiratory health, but data in young children are very limited. We examined the association of prenatal pesticide exposure with lower respiratory tract infections (LRTIs) and wheeze at one year of age in children from the Infants' Environmental Health (ISA) study in Costa Rica.

METHODS

We measured seven pesticide metabolites, including ethylenethiourea (ETU, metabolite of mancozeb), in maternal urine samples collected repeatedly during pregnancy. For each woman, we averaged pesticide concentrations during each half of pregnancy (≤20 and >20 weeks of gestation) and across repeated samples collected over the course of pregnancy. We collected information about LRTIs (n = 355) and wheezing (n = 272) during the first year of life from mothers when their children were 11-19 months old. We fit multivariable logistic regression models using high (quartile 4) vs. low (quartiles 1-3) urinary pesticide concentrations as exposures and adjusted models for maternal age, education, parity, gestational age at birth, and child sex.

RESULTS

Ten percent of the children had at least one LRTI and 39% had at least one episode of wheezing during their first year of life. Median (25-75th percentile) specific gravity-corrected urinary ETU concentrations during the first half, second half, and over the course of pregnancy were 3.4 (2.1-5.0), 3.3 (2.2-4.7), and 3.4 (2.4-5.0) ng/mL, respectively. We observed that high urinary ETU concentrations during the first half of pregnancy were associated with increased odds of LRTI (OR = 2.45; 95% CI: 0.96, 6.26), whereas high urinary ETU concentrations during the second half of pregnancy were associated with decreased odds of wheezing (OR = 0.50; 95% CI: 0.26, 0.96). We found that the association between high urinary ETU concentrations during the first half of pregnancy and LRTIs persisted among mother-child pairs with either high or low ETU concentrations during the second half. In contrast, the association of high urinary ETU concentrations during the second half of pregnancy with wheezing was attenuated when we simultaneously adjusted for urinary ETU concentrations during the first half. We observed null associations between other pesticide metabolites measured during pregnancy and respiratory outcomes.

CONCLUSIONS

Our data indicate that exposure to mancozeb/ETU during the first half of pregnancy may be associated with respiratory outcomes in the first year of life.

Environmental exposures in young adults with declining kidney function in a population at risk of Mesoamerican nephropathy

OBJECTIVES

There is an epidemic of Mesoamerican nephropathy (MeN) in Central America, where sugarcane production is prominent. Numerous causes are proposed, but to date limited evidence supports any one hypothesis. A nested case-control study using biosamples from a rural, community-based follow-up study of 350 young adults from Northwest Nicaragua at risk of MeN was conducted with the aim of characterising the associations between urinary concentrations of metals, pesticides and mycotoxins from samples collected in the first 6 months and decline in kidney function over 2 years.

METHODS

Urine samples collected at baseline (pre-sugarcane harvest) and the first 6 month follow-up (post-sugarcane harvest) visit were tested. Twelve metals and metalloids (aluminium, total arsenic, cadmium, chromium, cobalt, copper, lead, manganese, mercury, selenium, silicon and strontium) were analysed by inductively coupled plasma-mass spectrometry. Twelve pesticides or their metabolites (2,4-dichlorophenoxyacetic acid, 3-phenoxybenzoic acid, 4-fluoro-3-phenoxybenzoic acid, chloro-3,3,3-trifluoro-1-propen-1-yl-2,2-dimethylcyclopropanecarboxylic acid, cis/trans 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid, ethylenethiourea, glyphosate, 4-chloro-2-methylphenoxy acetic acid, 3-hydroxy-pyrimetanil, 5-hydroxytiabendazole, hydroxy-tebuconazole and 3,5,6-trichloro-2-pyridinol) and two mycotoxins (ochratoxin A (OTA) and citrinin (CIT)) were analysed by liquid chromatography coupled-mass spectrometry. Differences in the creatinine-corrected urinary concentrations of the measured exposures between outcome groups (participants with stable vs declining kidney function) were examined.

RESULTS

Elevated levels of aluminium and total arsenic as well as metabolites of several pesticides were detected across the population. No differences were identified between the declining and stable groups in the levels of metals or pesticides tested. OTA and CIT were below the limit of detection.

CONCLUSIONS

The tested metals, metalloids, pesticides and mycotoxins were not associated with loss of kidney function in participants at-risk of MeN.

Exposure to Pesticides and Health Effects on Farm Owners and Workers From Conventional and Organic Agricultural Farms in Costa Rica: Protocol for a Cross-Sectional Study

Background

Pesticide use is increasing in low- and middle-income countries (LMICs) including Costa Rica. This increase poses health risks to farm owners, farm workers, and communities living near agricultural farms.

Objective

We aimed to examine the health effects associated with occupational pesticide exposure in farm owners and workers from conventional and organic smallholder farms in Costa Rica.

Methods

We conducted a cross-sectional study involving 300 owners and workers from organic and conventional horticultural smallholder farms in Zarcero County, Costa Rica. During the baseline study visit, we administered a structured, tablet-based questionnaire to collect data on sociodemographic characteristics, pesticide exposure, and health conditions (eg, respiratory and allergic outcomes and acute pesticide intoxication symptoms) and administered a neurobehavioral test battery (eg, Finger Tapping Test and Purdue Pegboard); we measured blood pressure, anthropometry (height, weight, and waist circumference), and erythrocytic acetylcholinesterase activity and also collected urine samples. In addition, a functional neuroimaging assessment using near-infrared spectroscopy was conducted with a subset of 50 study participants. During the follow-up study visit (~2-4 weeks after the baseline), we administered participants a short questionnaire on recent pesticide exposure and farming practices and collected hair, toenail, and urine samples. Urine samples will be analyzed for various pesticide metabolites, whereas toenails and hair will be analyzed for manganese (Mn), a biomarker of exposure to Mn-containing fungicides. Self-reported pesticide exposure data will be used to develop exposure intensity scores using an exposure algorithm. Furthermore, exposure-outcome associations will be examined using linear and logistic mixed-effects regression models.

Results

Fieldwork for our study was conducted between May 2016 and August 2016. In total, 113 farm owners and 187 workers from 9 organic and 83 conventional horticultural smallholder farms were enrolled. Data analyses are ongoing and expected to be published between 2019 and 2020.

Conclusions

This study is one of the first to examine differences in health effects due to pesticide exposure between farm owners and workers from organic and conventional smallholder farms in an LMIC. We expect that this study will provide critical data on farming practices, exposure pathways, and how occupational exposure to pesticides may affect farm owners and workers’ health. Finally, we hope that this study will allow us to identify strategies to reduce pesticide exposure in farm owners and workers and will potentially lay the groundwork for a future longitudinal study of health outcomes in farm owners and workers exposed to pesticides.

International Registered Report Identifier (IRRID)

DERR1-10.2196/10914

Analysis of binding properties and interaction of thiabendazole and its metabolite with human serum albumin via multiple spectroscopic methods

Thiabendazole (TBZ), which is oxidized into 5-hydroxythiabendazole (5-OH-TBZ) in vivo, is a commonly used food preservative. Interactions of TBZ and 5-OH-TBZ with human serum albumin (HSA) were comprehensively studied via multiple spectroscopic methods and molecular docking. This study focussed on the mechanistic and structural information on binding of TBZ and 5-OH-TBZ to HSA to evaluate the impact of the food additive on HSA. ¹H NMR spectra of the two ligands showed the binding exists. ITC and fluorescence spectroscopy results revealed that TBZ was a stronger ligand, with a binding constant of 10⁵l/mol and formed a more stable complex with HSA than did 5-OH-TBZ via electrostatic interaction. Spectroscopic results (UV-vis, FT-IR, and CD) showed that TBZ and 5-OH-TBZ caused conformational changes in HSA, in which α-helix and β-turn transformed into β-sheet, causing HSA structure to loosen. Docking programs showed that both TBZ and 5-OH-TBZ bound to HSA via IB.