Determination of farm workers' exposure to pesticides by hair analysis

Computational simulations uncover enantioselective metabolism of chiral triazole fungicides by human CYP450 enzymes: A case study of tebuconazole

Tebuconazole (TEB), a prominent chiral triazole fungicide, has been extensively utilized for plant pathogen control globally. Despite experimental evidence of TEB metabolism in mammals, the enantioselectivity in the biotransformation of R- and S-TEB enantiomers by specific CYP450s remains elusive. In this work, integrated in silico simulations were employed to unveil the binding interactions and enantioselective metabolic fate of TEB enantiomers within human CYP1A2, 2B6, 2E1, and 3A4. Molecular dynamics (MD) simulations clearly delineated the binding specificity of R- and S-TEB to the four CYP450s, crucially determining their differences in metabolic activity and enantioselectivity. The primary driving force for robust ligand binding was identified as van der Waals interactions with CYP450s, particularly involving the hydrophobic residues. Mechanistic insights derived from quantum mechanics/molecular mechanics (QM/MM) calculations established C2-methyl hydroxylation as the predominant route of R-/S-TEB metabolism, while C6-hydroxylation and triazol epoxidation were deemed kinetically infeasible pathways. Specifically, the resulting hydroxy-R-TEB metabolite primarily originates from R-TEB biotransformation by 1A2, 2E1 and 3A4, whereas hydroxy-S-TEB is preferentially produced by 2B6. These findings significantly contribute to our comprehension of the binding specificity and enantioselective metabolic fate of chiral TEB by CYP450s, potentially informing further research on human health risk assessment associated with TEB exposure.

The epoxiconazole and tebuconazole fungicides impair granulosa cells functions partly through the aryl hydrocarbon receptor (AHR) signalling with contrasted effects in obese, normo-weight and polycystic ovarian syndrome (PCOS) patients

Polycystic ovarian syndrome (PCOS), frequently associated to obesity, is the main reproductive disorder in women in age to procreate. Some evidence suggests that pesticides can result in alterations of the female reproductive system, including polycystic ovary syndrome (PCOS). Here, we detected two fungicides, Tebuconazole (Tb) and Epoxiconazole (Epox) in the soils and waters of French area. Our hypothesis is that these two triazoles could be associated to the etiology of PCOS. We used the human KGN cell line and primary human granulosa cells (hGCs) from different group of patients: normal weight non PCOS (NW), normal weight PCOS (PCOS NW), obese (obese) and obese PCOS (PCOS obese). We exposed in vitro these cells to Tb and Epox from 0 up to 10 mM for 24 and 48 h and analysed cell viability and steroidogenesis. In hGCs NW, cell viability was reduced from 12.5 µM for Tb and 75 µM for Epox. In hGCs NW, Epox decreased progesterone (Pg) and estradiol (E2) secretions and inhibited STAR, HSD3B and CYP19A1 mRNA expressions from 25 µM and increased AHR mRNA expression from 75 µM. Tb exposure also reduced steroid secretion and STAR and CYP19A1 mRNA expressions and increased AHR mRNA expression but at cytotoxic concentrations. Silencing of AHR in KGN cells reduced inhibitory effects of Tb and Epox on steroid secretion. Tb and Epox exposure decreased more steroid secretion in hGCs from obese, PCOS NW and PCOS obese groups than in NW group. Moreover, we found a higher gene expression of AHR within these three groups. Taken together, both Epox and Tb reduced steroidogenesis in hGCs through partly AHR and Tb was more cytotoxic than Epox. These triazoles alter more strongly PCOS and/or obese hGCs suggesting that human with reproductive disorders are more sensitive to triazoles exposure.

Characterization of organic contaminants in hair for biomonitoring purposes

Biological monitoring is one way to assess human exposure to contaminants. Blood and urine are often used as biological matrices, but hair is an innovative and effective tool for quantifying more biomarkers over a wider exposure window. In order to improve the use of hair in exposure assessment, this article identifies relevant compounds in the literature to investigate hair contamination. Statistical analysis was performed to correlate the physical-chemical properties of the relevant compounds and their concentration levels in hair. Phthalates, pyrethroids and organophosphate flame retardants were chosen for further study of the interpretation of hair measurements for exposure assessment. No significant correlation was found between the average concentration levels in the literature and the physical-chemical properties of the selected compounds. This work also explores the properties of hair and the analytical process that may impact the quantification of organic contaminants in hair. The sample preparation method (sampling, storage, washing) were also studied and adaptations were suggested to improve the existing methods.

Sub-chronic exposure to hexaconazole affects the lipid metabolism of rats through mTOR-PPAR-γ/SREBP1 signaling pathway mediated by oxidative stress

Hexaconazole (Hex) is a widely used and high frequency detected triazole fungicide in agricultural products and environment which may pose potential toxicity to the nontargeted organisms. Hex had been reported to affect lipid homeostasis while the mechanism was undefined. This study aims to explore the characteristic lipidomic profiles and clarify the underlying signaling pathways of Hex-induced lipid metabolism disorder in rat liver. The results showed that sub-chronic exposure to environmental related concentrations of Hex caused histopathological changes, oxidative stress, fat accumulation, lipid biochemical parameter increase in rats. Moreover, the untargeted lipidomic analysis showed that the levels of TAG, PC, and PE and the pathway of glycerophospholipid metabolism were heavily altered by Hex. We further analyzed the lipid metabolism related genes and proteins which revealed that Hex exposure increased amount of lipogenesis by activating oxidative stress-mediated mTOR-PPAR-γ/SREBP1 signaling pathways. The imbalance of lipid homeostasis induced by Hex exposure might further lead to obesity, cardiovascular diseases (CVDs), and hyperlipidemia. Our results provided systematic and comprehensive evidence for the mechanism of Hex-induced lipid metabolism disorder at environmental concentrations and supplied a certain basis for its health risks assessment.

Environmental exposure to organophosphate pesticides and effects on cognitive functions in elementary school children in a Middle Eastern area

Although the fundamental reasons for cognitive function disorders have been well documented, little is known about the impact of environmental exposures, such as pesticides, on children's cognitive function development. This study investigated the effect of exposure to organophosphate pesticides on children's cognitive function. In order to determine various factors of exposure, hair samples were collected from 114 elementary school children who lived in Boyer-Ahmad County in the province of Kohgiluyeh and Boyer-Ahmad, Iran. A detailed questionnaire was utilized to gather demographic information and exposure profile. Pesticides were detected in hair samples using a gas chromatography-mass spectrometer (GC-MS); also, cognitive function was assessed using the trail-making test (TMT), which was divided into two parts: TMT-part A and TMT-part B. Participants in the study were 10.12 ± 1.440 years old on average. Children in rural areas had higher mean total pesticide concentrations (13.612 ± 22.01 ng/g) than those who lived in the urban areas (1.801 ± 1.32). The results revealed that boys (46.44 s and 92.37 s) completed the TMT-part A and part B tests in less time than girls (54.95 s and 109.82 s), respectively, and showed better performance (2.14) on the cognitive function exam than girls (2.07). Diazinon and TMT-part B were positively correlated (p < 0.05). With the increase in pesticides, there was no discernible difference in cognitive function. Pesticide use throughout a child's development may affect certain cognitive function indicators. In order to assess causal relationships, group studies and case studies are required because the current research was cross-sectional in nature.

Aggravation of TGFβ1-Smad Pathway and Autoimmune Myocarditis by Fungicide (Tebuconazole) Exposure

Myocarditis is an inflammatory cardiac disorder and the primary cause of heart failure in young adults. Its origins can be attributed to various factors, including bacterial or viral infections, exposure to toxins or drugs, endocrine disruptors (EDs), and autoimmune processes. Tebuconazole (TEB), which is a member of the triazole fungicide family, is utilized to safeguard agricultural crop plants against fungal pathogens. Although TEB poses serious threats to mammal health, the information about how it induces toxic effects through various pathways, particularly in autoimmune diseases, are still limited. Thus, the aim of this paper was to evaluate the effect of TEB exposure in autoimmune myocarditis (AM). To induce AM, rats were immunized with porcine cardiac myosin and exposed to TEB for 21 days. Thereafter, animals were sacrificed, and histological, biochemical, and molecular analyses were performed. TEB exposure increased heart weight, systolic blood pressure and heart rate already augmented by AM. Additionally, it significantly increased creatine phosphokinase heart (CK-MB), creatine phosphokinase (CPK), cardiac troponin T (cTnT), and cardiac troponin I (cTnI), as compared to the control. From the histological perspective, TEB exacerbates the histological damage induced by AM (necrosis, inflammation and cell infiltration) and increased fibrosis and collagen deposition. TEB exposure strongly increased pro-inflammatory cytokines and prooxidant levels (O2^-, H₂O₂, NO₂^-, lipid peroxidation) and reduced antioxidant enzyme levels, which were already dysregulated by AM. Additionally, TEB increased NOX-4 expression and the TGFβ1-Smads pathway already activated by AM. Overall, our results showed that TEB exposure strongly aggravated the cardiotoxicity induced by AM.

Rapid LC-MS/MS quantification of Organophosphate non-specific metabolites in hair using alkaline extraction approach

Assessing human exposure to commonly used, highly toxic, but non-persistent organophosphates (OPs) is challenging because these toxicants are readily biotransformed into dialkyl phosphates (DAPs) and other metabolites. Growing hair accumulates toxicants and their metabolites, which makes hair a valuable non-invasively sampled matrix that can be used to retrospectively examine chemical exposure. However, the efficient quantification of hydrophilic DAP compounds in hair is challenging due to complex hair matrix effects. To improve upon existing methods, we first examined the acid dissociation constants (pKa) of DAPs and amino acids (major components in hair) and identified the best pH conditions for minimizing matrix effects. We hypothesized that under basic pH conditions DAPs and amino acids would be negatively charged and have weak interactions favorable to DAP dissociation from the matrix. To test this, we compared the efficiency of various pH conditions of suitable solvents to extract six DAPs from hair samples, and we quantified these DAPs using liquid chromatography-tandem mass spectroscopy (LC-MS/MS). As expected, a basic extraction (methanol with 2% NH4OH) approach had the highest extraction efficiency and yielded satisfactory recoveries for all six DAPs (72%-152%) without matrix effects. Additionally, the alkaline extract can be directly injected into the LC-MS/MS. This relatively rapid and simple procedure allowed us to process up to 90 samples per week with reproducible results. To our knowledge, this is the first method to quantify all six DAPs simultaneously in hair using LC-MS/MS with electrospray ionization (ESI) in negative ion mode. Finally, we demonstrated the feasibility of measuring DAP levels in hair samples from patients affected with amyotrophic lateral sclerosis (ALS), a neurodegenerative disease potentially linked to OP exposure. Due to our optimized solvent extraction process, the method we have developed is compatible with the rapidity and sensitivity needed for hair analysis applied to population biomonitoring.

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.

Simple and rapid method for 336 multiresidual pesticide analysis in saliva, determination of their chemical stabilities, and biomonitoring of farmers

Simultaneous multiresidual pesticide analysis of saliva samples was performed using scaled-down QuEChERS extraction with LC-MS/MS and GC-MS/MS. The optimum extraction procedure using acidified acetonitrile was applicable to 336 pesticides (287 for LC-MS/MS and 49 for GC-MS/MS). To determine pesticide multiresidues in saliva, 100 μL of the sample was extracted with 200 μL of 0.1% formic acid in acetonitrile, and the initial extract was partitioned with 40 mg of MgSO₄ and 10 mg of NaCl. The organic supernatants (120 μL) were then mixed with acetonitrile (30 μL) for matrix-matching (4:1, v/v), and the final extract solution was injected into the LC-MS/MS (4 μL) and GC-MS/MS (2 μL) systems. The established analytical method showed a good LOQs between 5 and 25 ng/mL with reliable accuracy/precision values and recovery results (50-140%) for the target pesticides. Under the two different storage conditions, most of the analytes did not undergo chemical changes in the saliva samples, whereas some pesticides were more stable in freeze-thaw processes than those left at room temperature. Biomonitoring of farmers (ten mixers and ten sprayers) was successfully applied using the validated method, and two carbamates (fenobucarb and propamocarb) were determined at trace concentrations (12.5-675.0 ng/mL from 11 positively detected samples).

Triazole fungicide tebuconazole induces apoptosis through ROS-mediated endoplasmic reticulum stress pathway

Tebuconazole (TEB) is a common triazole fungicide that has been widely applied in the treatment of fungal diseases. It is reported that TEB could exert harmful effects on mammals' health. However, the molecular mechanism involved in TEB toxicity remain undefined. Our study aimed to investigate the mechanisms of TEB-induced toxicity in intestinal cells. We found that TEB stimulates apoptosis through the mitochondrial pathway. Additionally, TEB triggers endoplasmic reticulum (ER) stress as demonstrated by the activation of the three arms of unfolded protein response (UPR). The incubation with the chemical chaperone 4-phenylbutyrate (4-PBA) alleviated ER stress and reduced TEB-induced apoptosis, suggesting that ER stress plays an important role in mediating TEB-induced toxicity. Furthermore, inhibition of ROS by N-acetylcysteine (NAC) inhibited TEB-induced ER stress and apoptosis. Taken together, these findings suggest that TEB exerts its toxic effects in HCT116 cells by inducing apoptosis through ROS-mediated ER stress and mitochondrial apoptotic pathway.

The fungicide Tebuconazole induces electromechanical cardiotoxicity in murine heart and human cardiomyocytes derived from induced pluripotent stem cells

Tebuconazole (TEB) is an important fungicide that belongs to the triazole family. It is widely used in agriculture and its use has experienced a tremendous increase in the last decade. The long-term exposure of humans to this pesticide is a real threat because it is stable in water and soil. The association between long-term exposure to TEB and damage of several biological systems, including hepatotoxicity and cardiotoxicity is evident, however, acute toxicological studies to reveal the toxicity of TEB are limited. This research paper addressed the acute exposure of TEB in murine hearts, cardiomyocytes, and human cardiomyocytes derived from an induced pluripotent stem cell (hiPSC-CMs), spelling out TEB's impact on electromechanical properties of the cardiac tissue. In ex vivo experiments, TEB dose dependently, caused significant electrocardiogram (ECG) remodeling with prolonged PR and QTc interval duration. The TEB was also able to change the action potential waveform in murine cardiomyocytes and hiPSC-CMs. These effects were associated with the ability of the compound to block the L-type calcium current (IC₅₀ = 33.2 ± 7.4 μmol.l^-1) and total outward potassium current (IC₅₀ = 5.7 ± 1.5 μmol.l^-1). TEB also increased the sodium/calcium exchanger current in its forward and reverse modes. Additionally, sarcomere shortening and calcium transient in isolated cardiomyocytes were enhanced when cells were exposed to TEB at 30 μmol.l^-1. Combined, our results demonstrated that acute TEB exposure affects the cardiomyocyte's electro-contractile properties and triggers the appearance of ECG abnormalities.

The discovery of combined toxicity effects and mechanisms of hexaconazole and arsenic to mice based on untargeted metabolomics

The high detected frequencies of hexaconazole (Hex) and arsenic (As) increased the probabilities of their co-existence in agricultural products. However, the combined toxicity effect and mechanism of action for these two pollutants were still unclear. In this study, an untargeted metabolomics method with ultra high performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS) was developed to monitor the changes of endogenous metabolites and metabolism pathways in mice liver. Our study revealed that significant differences in metabolomics profiles were observed after Hex, As, and Hex+As exposure for 90 d. Hex exposure altered 54 metabolites and 11 pathways significantly which were mainly lipid-related. For As exposure, 63 metabolites and 9 pathways were affected most of which were amino acid-related. Hex+As induced 93 metabolites changes with 34% was lipids and lipid-like molecules and 22% was organic acids and derivatives. Hex+As exposure shared the pathways that altered by Hex and As indicated that the interaction of Hex and As might be independent action. The results of this study could provide an important insight for understanding the mechanism of combined toxicity for Hex and As and be helpful for evaluating their health risk to human.

Association between occupational and environmental pesticide exposure in Cukurova region by hair and blood biomonitoring

This study assesses association between occupational and environmental pesticide exposure on pesticide applicators directly exposed to pesticides and inhabitants of the Cukurova region by analyzing blood and hair samples. Hair and blood samples were collected from 132 volunteers, 66 of whom are pesticide applicators, and the rest are non-farmer residents, in 10 villages nearby the Ceyhan River between March and June in 2017. Samples were then analyzed via the liquid chromatography-tandem mass spectrometer. As the analysis result, a total number of 31 pesticides were detected in hair samples, whereas a total number of 15 pesticides were observed in blood samples. Twenty of the pesticides (64.5%) detected in the hair and 3 (20%) detected in the blood were significantly higher in the applicators than the non-farm residents. Also, 5 pesticides (16.1%) observed in the hair and 7 observed (46.6%) in the blood were banned pesticides. This study investigated the pesticide exposures on people living in the region via hair and blood samples. Our study revealed that, in addition to individuals who are occupationally exposed to pesticides, individuals from all parts of the society, especially those living in the agricultural region, have a certain level of pesticide exposure.

Population-based biomonitoring of exposure to persistent and non-persistent organic pollutants in the Grand Duchy of Luxembourg: Results from hair analysis

Environmental exposure of humans to pollutants has been associated with adverse health outcomes, but few studies have evaluated the multiple exposure of general populations. In the present study, we used hair analysis to assess the exposure of a general adult population (n = 497) in Luxembourg to 34 persistent and 33 non-persistent organic pollutants from 11 chemical families, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), and pyrethroid pesticides (PYRs). We detected 24 persistent and 29 non-persistent organic pollutants, with 17 pollutants being detected in more than 50% of hair samples. The median concentrations for pollutants detected in 100% of the samples were 0.37 pg/mg for lindane (γ-HCH), 0.15 pg/mg for hexachlorobenzene (HCB), 14.1 pg/mg for p-nitrophenyl (PNP), and 0.10 pg/mg for trifluralin. Each participant in this study had detectable levels of at least 10 of the pollutants analyzed, and 50% of participants had 19 or more, suggesting the simultaneous exposure to numerous different pollutants among our study population. Significant correlations were often found between pollutants from the same family, with the strongest being found between two PYR metabolites, trans/cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-carboxylic acid (Cl₂CA) and 3-phenoxybenzoic acid (3-PBA). Results from multiple linear regression analyses showed that sex, age and/or body mass index were significantly associated with 15 out of the 17 frequently detected pollutants. The current study is the first nationwide biomonitoring investigating organic contaminants in the Luxembourg population using hair analysis.

Method for the simultaneous analysis of 300 pesticide residues in hair by LC-MS/MS and GC-MS/MS, and its application to biomonitoring of agricultural workers

Multiresidual pesticide analysis in hair can provide useful perspectives on the relationship between pesticides and human health. To establish a rapid and simultaneous analytical method using LC-MS/MS and GC-MS/MS, optimization of hair pulverization, extraction solvent and purification with dispersive SPE was performed for 300 pesticides. Hair pulverization was standardized with a ball mill, at 30 Hz for 20 min (10 min twice), using 3-mm diameter beads. For extraction, 0.1% formic acid in acetonitrile was selected, and PSA d-SPE was chosen for clean-up among three different types of solid phase extraction. The limits of quantitation (LOQs) in this method were between 2.5 and 7.5 pg mg^-1. In recovery test, fifty milligrams of hair powder were extracted with 0.1% formic acid in acetonitrile, and incubated for three h at 40 ℃. The crude extract was treated using PSA-dSPE, dried under nitrogen gas, and reconstructed with acetonitrile. An aliquot was analyzed with LC- and GC-MS/MS. Recovery ranges were 22.7-131.1%, in LC-MS/MS analysis, and 81.1-151.8% in GC-MS/MS analysis. The validated analysis systems were applied to biomonitoring of ten agricultural workers, and residues of 28 target pesticides were detected in their hair.

Hair versus urine for the biomonitoring of pesticide exposure: Results from a pilot cohort study on pregnant women

BACKGROUND/AIM

The quantitative assessment of human exposure to contaminants such as pesticides is a crucial step in the characterization of exposure-associated risk. For this purpose, biomonitoring is often privileged as it presents the advantage of integrating all the possible sources and routes of exposure and of being representative of the internal dose resulting from exposure. Although biological fluids such as urine and blood have been used to date for this purpose, increasing interest has also been observed over the past decade for hair analysis. The present work aimed at comparing the information obtained from the analysis of urine versus hair regarding exposure to pesticides in a pilot cohort of pregnant women.

METHODS

In ninety-three pregnant women included in the pilot of the French cohort ELFE, one urine and one hair sample were collected simultaneously from each subject at the maternity. Samples were analyzed using GC-MS/MS analytical methods allowing for the detection of both parent pesticides and metabolites, and designed to be as similar as possible between urine and hair for reliable inter-matrix comparison. Fifty-two biomarkers of exposure were targeted, including parents and metabolites of organochlorines, organophosphates, pyrethroids, carbamates, phenylpyrazoles and other pesticides.

RESULTS

The number of different compounds detected ranged from 16 to 27 (median = 22) in hair, and from 3 to 22 (median = 12) in urine. In hair, 24 compounds were found in > 40% of the individuals, whereas only 12 compounds presented the same frequency of detection in urine. Among the chemicals detected in > 80% of both hair and urine samples, only one (pentachlorophenol) showed a signification correlation between hair and urine concentrations.

CONCLUSIONS

The present results highlight the multiple exposure of the pregnant women included in this cohort and suggest that hair provides more comprehensive information on pesticide exposure than urine analysis. This study thus supports the relevance of hair analysis in future epidemiological studies investigating association between exposure and adverse health effects.

Liquid chromatography tandem mass spectrometry for the determination of nine insecticides and fungicides in human postmortem blood and urine

Pesticide poisoning is a common occurrence due to their widespread use, easy access and high toxicity even in small concentrations. The most common poisoning fatalities have been observed due to exposure to organophosphates, carbamates and neonicotinoids, thus development of a method for the rapid determination of these compounds in blood and urine is of great importance for clinical and toxicology laboratories. A simple, fast and reliable method was developed for the determination of 9 pesticides in blood and urine using HPLC-MS/MS instrumentation. In order to find the most suitable sample pretreatment technique, three different sample preparation procedures: SPE, protein precipitation and QuEChERS were compared. The final optimized analytical method was fully validated with the values of parameters such as calibration linearity, accuracy, precision, recovery, matrix effect and stability being acceptable. The method proved reliable, accurate, robust and sensitive and was successfully applied for the quantitation of pesticides in three postmortem cases of pesticides poisoning.

Analysis of tebuconazole residues in coconut water, kernel and leaves using LC-MS/MS

A method was validated for determining tebuconazole residues in coconut water, kernel and leaves using Liquid chromatography-Mass spectrometry/Mass spectrometry (LC-MS/MS) with electro spray ionization in positive ion mode. Samples were extracted with acetonitrile and subsequent clean-up was done using dispersive solid phase extraction. Recovery ranged between 70 and 114.39 % and the RSD was between 0.64 and 10.24 %. Root feeding studies with tebuconazole @ 5 and 10 mL/100 mL of water/tree revealed the presence of tebuconazole residues in coconut leaves until three days after treatment but dissipated to below quantifiable limit on 5th day at single dose while the residues went below quantifiable limit after 10 days at double the dose. Residues were below quantifiable limit in coconut water and kernel until three days. Data obtained from the study were used for estimating the risks associated with the exposures to tebuconazole residues in coconut.

DNA damage effect of cyprodinil and thiacloprid in adult zebrafish gills

Cyprodinil and thiacloprid are two of the most commonly used pesticides in Turkey. It is more likely to reach humans or animals due to their widespread use. This study aims to investigate whether there is a DNA damage risk due to cyprodinil and thiacloprid exposure. Zebrafish, which is used as a model organism in health and environmental research, and comet assay were chosen to demonstrate this damage. Ten zebrafish per group were exposed to 2 different concentrations for each pesticides (0.31 and 0.155 mg/L for cyprodinil and 1.64 and 0.82 mg/L for thiacloprid) for 21 days. After, gills were excised and comet assay was performed. Photos of an average of 50 cells per slide were taken and were analyzed with visual evaluation program. DNA damage was found to be increased in the 0.31 mg/L cyprodinil, 0.82 mg/L thiacloprid, and 1.64 mg/L thiacloprid treatment groups when compared to the control group (p < 0.001). Average tail DNA percentage parameter values were 9.45 ± 0.51, 10.30 ± 0.34, 11.17 ± 0.33, and 2.47 ± 0.06 respectively. Cyprodinil and thiacloprid were identified as genotoxic agents that should be investigated further.

Tebuconazole exposure disrupts placental function and causes fetal low birth weight in rats

Tebuconazole (TEB) is one of the widely used broad-spectrum triazole fungicides. Its accumulation in mammals leads to various endocrine disruptions. However, it is unclear whether the exposure of TEB during pregnancy affects the growth and development of fetus and placenta. Here, TEB was exposed to pregnant Sprague-Dawley female rats from gestational days 12-21 of 0, 25, 50 or 100 mg/kg for 10 days. TEB reduced placental estradiol levels. TEB disrupted the structure and function of the placenta, leading to hypertrophy, fibrin exudation, edema, calcification, arterial fibroblast proliferation, and trophoblastic infarction. RNA-seq analysis showed that TEB mainly down-regulated the expression of iron transport genes and up-regulated the expression of genes for immune/inflammatory responses. Further qPCR showed that TEB down-regulated Tfrc, Hamp, Eif2ak2 and up-regulated the expression of Cd34, Cd36, Jag1, Pln, Cyp1a1, Esrra, and Aqp1 at 50 and 100 mg/kg. Western blot and semi-quantitative immunohistochemical staining also demonstrated that TEB lowered the levels of TFRC and EIF2AK2 and increased the levels of CD34, CD36, JAG1, CYP1A1, and ESRRA at 50 and 100 mg/kg. In conclusion, TEB severely damages the structure and function of the placenta, leading to hypertrophy of the placenta, low birth weight and feminization of the male fetus possibly via several pathways including iron transport and TNF signaling.

Gestational exposure to tebuconazole affects the development of rat fetal Leydig cells

Tebuconazole is a triazole fungicide, used in agriculture to treat phytopathogenic fungi, and as a biocide, has been reported to be related to reproductive and developmental toxicity. The purpose of this study was to investigate the effect of tebuconazole exposure on rat fetal Leydig cells and fetal testis during pregnancy. Pregnant Sprague-Dawley rats were randomly divided into 4 groups, daily gavaged with corn oil (as a control), 25, 50, and 100 mg/kg body weight tebuconazole for 10 days (from the 12th day of pregnancy). Tebuconazole increased fetal serum testosterone and progesterone levels at a dose of 100 mg/kg. Exposure to 100 mg/kg tebuconazole significantly caused an increase in the number of fetal Leydig cells per testis without inducing cell aggregation. Tebuconazole up-regulated the expression of Star, Cyp11a1, Hsd17b3, and Fshr and their proteins. Further investigation found that tebuconazole caused increased phosphorylation of AKT1, ERK1/2, and mTOR, the level of BCL2, as well as the decrease of Beclin1, LC3B, and BAX, which may contribute to the fetal Leydig cell autophagy and proliferation. In conclusion, in utero exposure of tebuconazole causes the proliferation of fetal Leydig cells.

Tebuconazole induced oxidative stress and histopathological alterations in adult rat heart

TEB belongs to the family of triazole fungicides and it is used to protect agricultural crop plants from fungal pathogens. The information regarding its cardiotoxic effects through different pathways particularly by perturbing the oxidative balance and causing damage to the myocardium is still limited. In the present study, oxidative and histopathologic damages caused by TEB in the cardiac tissue of male adult rats, were evaluated. Rats were exposed orally to TEB at 0.9, 9, 27 and 45 mg/kg b.w. for 28 days. Results showed that following TEB treatment malondialdehyde (MDA), protein carbonyl (PC), advanced oxidation protein product (AOPP), antioxidant enzyme activities (GPx and GR) and GSSG levels increased, while GSH levels and thus the GSH/GSSG ratio decreased. Superoxide dismutase (SOD) and catalase (CAT) initially increased at the doses of 0.9, 9 and 27 mg/kg b.w. and then decreased at the dose of 45 mg/kg b.w. Moreover, western blot analysis showed that TEB increased SOD1, CAT and HSP70 protein levels after 24 h. Furthermore, TEB induced various histological changes in the myocardium, including leucocytic infiltration, hemorrhage congestion of cardiac blood vessels and cytoplasmic vacuolization. Therefore, our investigation revealed, that TEB exhibits cardiotoxic effects by changing oxidative balance and damaging the cardiac tissue.

Exposure to multiclass pesticides among female adult population in two Chinese cities revealed by hair analysis

The high use of pesticides worldwide and the constant exposure of humans to these toxic-by-design chemicals have drawn the attention on the possible consequences on human health. However, information on the exposure of the general population to pesticides remain very limited in most countries, especially in urban areas. In the present work, hair analysis was conducted to investigate the exposure of 204 urban women living in two Chinese cities (Baoding and Dalian) to 110 pesticides and 30 metabolites of the following families: organochlorines, organophosphates, carbamates, pyrethroids, neonicotinoids, phenylpyrazoles, acid herbicides, urea herbicides and azoles. Results showed that 71 pesticides and 23 metabolites were found in the hair samples, with concentrations ranging up to 1070 pg/mg in hair. In each hair sample, the number of detected chemicals ranged from 25 to 50, demonstrating the cumulative exposure to pesticides among Chinese women in the studied regions. The concentrations of 38 chemicals (e.g., p-nitrophenol, diethyldithiophosphate, λ-cyhalothrin, permethrin, carbendazim and tebuconazole) were significantly different between women in Baoding and Dalian, indicating the regional differences in exposure to pesticide. Using a multiple regression analysis, we found that concentrations of a few dominant pesticides were associated with age, body mass index (BMI), cooking frequency and regions. These results can provide baseline information on exposure of female adult Chinese population to multiple pesticides and support future studies focused on the health effects associated with pesticide exposure.

Cumulative exposure to organic pollutants of French children assessed by hair analysis

Children represent one of the most vulnerable parts of the population regarding the effects of pollutants exposure on health. In this study, hair samples were collected between October 2013 and August 2015 from 142 French children originating from different geographical areas (urban and rural) and analysed with a GC/MS-MS method, allowing for the detection of 55 biomarkers for pesticides and metabolites both persistent and non-persistent from different families, including: organochlorines, organophosphates, pyrethroids, azoles, dinitroanilines, oxadiazines, phenylpyrazoles and carboxamidas; 4 polychlorobiphenyls (PCBs) and 5 polybromodiphenylethers (PBDEs). The number of compounds detected in each sample ranged from 9 up to 37 (21 on average), which clearly highlighted the cumulative exposure of the children. The results also showed a wide range of concentration of the pollutants in hair (often more than 100 times higher in the most exposed child compared to the less exposed), suggesting significant disparities in the exposure level, even in children living in the same area. In addition to the detection of currently used chemicals, the presence of persistent organic pollutants (POPs) in children also suggests that the French population is still exposed to POPs nowadays. PCP, DEP, PNP, 3Me4NP, trans-Cl2CA, 3PBA, fipronil and fipronil sulfone, presented statistically significant higher concentration in the hair of boys compared to girls. PCP, PNP and 3Me4NP presented statistically significant higher concentration in younger children. Finally, this study also suggests that local environmental contamination would not be the main source of exposure, and that individual specificities (habits, diet…) would be the main contributors to the exposure to the pollutants analysed here. The present study strongly supports the relevance of hair for the biomonitoring of exposure and provides the first values of organic pollutant concentration in the hair of French children.

Hair as a matrix to evaluate cumulative and aggregate exposure to pesticides in winegrowers

INTRODUCTION

Vineyard is a crop where a large number of pesticides are applied; exposure to pesticides may occur in farmers and the general population living close to the treated area. This work aimed to investigate hair as a matrix for the assessment of cumulative and aggregate exposure to pesticides in potentially exposed individuals.

METHODS

Twenty agricultural workers (AW), 4 agricultural worker relatives (AR), and 5 research staff members (RS) were involved in the study. Hair samples were collected before and after the application season (PRE- and POST-EXP samples) to obtain 18 paired samples. Records with the name and the quantity of applied pesticides were obtained; twenty-seven pesticides were measured in hair by solvent extraction and LC-MS/MS.

RESULTS

During the study season, AW applied 14 different pesticides with median amount ranging from 12 to 7200 g. The most popular pesticides were dimethomorph, penconazole, cyazofamid, fenamidone and quinoxyfen, applied from 94 to 69% of AW. In AW, in PRE-EXP samples the majority of used pesticides was detectable (with detection rates from 6 to 88%), with median concentrations of few pg/mg hair; in the POST-EXP samples the frequency of detected values increased (from 25 to 100%), with median concentrations up to two orders of magnitude higher. In AR, most pesticides were quantifiable only in POST-EXP samples and with lower concentration in comparison with AW; in RS, in both PRE- and POST-EXP samples only a few pesticides were quantifiable with very low levels. In AW, a linear correlation (r = 0.682 on log-transformed data, p < 0.01) was found between the total amounts of applied pesticides during the season and their concentration in hair.

CONCLUSION

The study shows that the majority of assessed pesticides was incorporated into hair of AW and AR. The increased frequency of detection and level at the end of the season and the correlation between pesticide in hair and the amount of applied pesticides, reinforce the use of hair for quantitative biomonitoring of cumulative exposure to pesticides.

Fungicide Tebuconazole Influences the Structure of Human Serum Albumin Molecule

Studies of interactions between pesticides and target mammalian proteins are important steps toward understanding the pesticide's toxicity. Using calorimetric and spectroscopic methods, the interaction between triazole fungicide tebuconazole and human serum albumin has been investigated. The spectroscopic techniques showed that fluorescence quenching of human serum albumin by tebuconazole was the result of the formation of tebuconazole/human serum albumin complex with the static type as the dominant mechanism. The association constant was found to be 8.51 × 103 L/mol. The thermodynamic parameters were obtained as ΔH = -56.964 kJ/mol, ΔS = -115.98 J/mol·K. The main active interactions forming the tebuconazole/human serum albumin complex were identified as the interplay between hydrogen bonds and/or van der Waals forces, based on thermodynamic experiments. These binding modes were corroborated well by the predictions of molecular modeling. Hydrogen bonding of tebuconazole with Arg222, Ala215 and Ala291 of human serum albumin played a relevant role in binding. The conformation changes in secondary structure were characterized by circular dichroism and 3D fluorescence spectra.

A Quantitative Tandem Mass Spectrometry and Scaled-Down QuEChERS Approach for Simultaneous Analysis of Pesticide Multiresidues in Human Urine

Multiresidual pesticide determination in a biological sample is essential for an immediate decision and response related to various pesticide intoxications. A rapid and simultaneous analytical method for 260 pesticides in human urine was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). High speed positive/negative switching electrospray ionization (ESI) mode was used, and scheduled multiple reaction monitoring (MRM) was optimized. Three versions of scaled-down QuEChERS procedures were evaluated, and the procedure using non-buffer reagents (magnesium sulfate and sodium chloride) and excluding cleanup steps was selected for optimum pesticide extraction. The limit of quantitation (LOQ) in this methodology was 10 ng/mL for each target pesticide, and correlation coefficient (r²) values of calibration curves were ≥0.988 (linearity range; 10–250 ng/mL). In accuracy and precision tests, the relative error ranges were −18.4% to 19.5%, with relative standard deviation (RSD) 2.1%–19.9% at an LOQ level (10 ng/mL), and −14.7% to 14.9% (RSD; 0.6%–14.9%) at higher concentrations (50, 150, and 250 ng/mL). Recovery range was 54.2%–113.9% (RSD; 0.3%–20.0%), and the soft matrix effect (range; −20% to 20%) was observed in 75.4% of target pesticides. The established bioanalytical methods are sufficient for application to biomonitoring in agricultural exposures and applicable in the forensic and clinic.

Efficacy of biological agents and compost on growth and resistance of tomatoes to late blight

This study identified biocontrol measures for improving plant quality and resistance under biotic stress caused by the most devastating pathogen in tomato production. The management of plant diseases are dependent on a variety of factors. Two important variables are the soil quality and its bacterial/fungal community. However, the interaction of these factors is not well understood and remains problematic in producing healthy crops. Here, the effect of oak-bark compost, Bacillus subtilis subsp. subtilis, Trichoderma harzianum and two commercial products (FZB24 and FZB42) were investigated on tomato growth, production of metabolites and resistance under biotic stress condition (infection with Phytophthora infestans). Oak-bark compost, B. subtilis subsp. subtilis, and T. harzianum significantly enhanced plant growth and immunity when exposed to P. infestans. However, the commercial products were not as effective in promoting growth, with FZB42 having the weakest protection. Furthermore, elevated levels of anthocyanins did not correlate with enhanced plant resistance. Overall, the most effective and consistent plant protection was obtained when B. subtilis subsp. subtilis was combined with oak-bark compost. In contrast, the combination of T. harzianum and oak-bark compost resulted in increased disease severity. The use of compost in combination with bio-agents should, therefore, be evaluated carefully for a reliable and consistent tomato protection.

Anxiety-associated behavior and genotoxicity found in adult Danio rerio exposed to tebuconazole-based commercial product

The effects of different concentrations of commercial product based on tebuconazole, on adults of Danio rerio, were evaluated through novel tank diving test and micronucleus and comet assay tests. A total of 320 adult D. rerio were divided into eight tanks and exposed to concentrations of 0; 100; 200 and 300 μg/L the commercial product based on tebuconazole, with their respective replicates at 24, 72 and 96 h. The results showed a behavioral deviation of zebrafish and a significant (p < 0.05) increase in DNA damage as a function of exposed time and different concentrations of the commercial product in relation to the negative control. The results obtained in this study allow to conclude that tebuconazole has effects on adults of Danio rerio, inducing genotoxicity and mutagenicity, as well as altering neurological functions related to the change in the behavior of adults.

Interaction of the Fungicide Tebuconazole with Human Serum Albumin: A Preliminary Study

The interactions between the fungicide tebuconazole and human serum albumin were investigated using fluorescence and circular dichroism spectroscopies. The experimental results showed that the fluorescence quenching of the protein by the tebuconazole molecule was a result of the formation of a ligand-protein complex with a binding constant of 8.51×103 l.mol−1 and the number of binding sites in the macromolecule was close to 1. These findings demonstrated the fact that although the binding affinity of tebuconazole to the protein may be slight, it was very similar to other triazole fungicides. In addition, tebuconazole stabilized the α-helical secondary structure of the human serum albumin due to the increase of the α-content in the protein macromolecule.

Identification of new tetrahydroxylated metabolites of Polycyclic Aromatic Hydrocarbons in hair as biomarkers of exposure and signature of DNA adduct levels

The present study addresses the hypothesis that the concentration of tetrahydroxylated Polycylic Aromatic Hydrocarbons (tetra-OH-PAHs) in hair might be a useful biomarker of human exposure to PAHs, providing quantitative assessment of the internal dose, as well as information on the associated toxicity in relation to individual's specific metabolism. By means of animal models, this work aimed at identifying new tetra-OH-PAHs which can be released from the hydrolysis of DNA-adducts and can also be directly detected in biological matrices usually used in the field of biomonitoring such as hair and urine. Results obtained from a targeted gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) approach, demonstrated the presence of 8 tetrahydroxylated metabolites in DNA and 23 in hairs of rats exposed to mixtures of PAHs, which had never been analyzed before. Ten tetra-OH-PAHs were clearly characterized by using their analytical standards, corresponding to 4 parent PAHs (phenanthrene, chrysene, benz[a]anthracene and benzo[a]pyrene) whereas 13 tetra-OH-PAHs from 3 other parents (anthracene, fluoranthene and benz[k]fluoranthene) were detected but not yet characterized. No tetrahydroxylated metabolite has been clearly identified for naphthalene, fluorene, benzo[b]fluoranthene, benzo[g,h,i]perylene, or dibenzo[a,h]anthracene, which can all potentially form adducts. The relevance of tetra-OH-PAH analysis in hair as biomarkers of PAH exposure was evaluated in a dose-response study conducted on 64 rats (Long Evans females/n = 8 per groups) under repeated exposure (3 times per week) to a mixture of 16 PAHs at low doses (0.01-0.8 mg/kg) for 90 days. Most of the tetra-OH-PAHs targeted in the method were detected in the hairs of the rats, regardless of the dose of exposure. Significant linear relationships (R² ranging from 0.558 to 0.964, p < 0.001) were observed between the administered dose and the tetra-OH-PAH concentrations in the hairs for 20 out of the 23 metabolites. By widening the range of PAH metabolites used as biomarkers of exposure so as to include the analysis of PAH tetrahydroxylated forms (especially those exhibiting more than 5 aromatic rings), the present methodology will enable multi-exposure assessments which are more accurately representative of actual situations of exposure to PAHs.

Transgenerational epigenetics and environmental justice

Human transmission to offspring and future generations of acquired epigenetic modifications has not been definitively established, although there are several environmental exposures with suggestive evidence. This article uses three examples of hazardous substances with greater exposures in vulnerable populations: pesticides, lead, and diesel exhaust. It then considers whether, if there were scientific evidence of transgenerational epigenetic inheritance, there would be greater attention given to concerns about environmental justice in environmental laws, regulations, and policies at all levels of government. To provide a broader perspective on environmental justice the article discusses two of the most commonly cited approaches to environmental justice. John Rawls's theory of justice as fairness, a form of egalitarianism, is frequently invoked for the principle that differential treatment of individuals is justified only if actions are designed to benefit those with the greatest need. Another theory, the capabilities approach of Amartya Sen and Martha Nussbaum, focuses on whether essential capabilities of society, such as life and health, are made available to all individuals. In applying principles of environmental justice the article considers whether there is a heightened societal obligation to protect the most vulnerable individuals from hazardous exposures that could adversely affect their offspring through epigenetic mechanisms. It concludes that unless there were compelling evidence of transgenerational epigenetic harms, it is unlikely that there would be a significant impetus to adopt new policies to prevent epigenetic harms by invoking principles of environmental justice.

Effects of triazole fungicides on androgenic disruption and CYP3A4 enzyme activity

Triazole fungicides are widely used as broad-spectrum fungicides, non-steroidal antiestrogens and for various industrial applications. Their residues have been frequently detected in multiple environmental and human matrices. The increasingly reported toxicity incidents have led triazole fungicides as emerging contaminants of environmental and public health concern. However, whether triazole fungicides behave as endocrine disruptors by directly mimicking environmental androgens/antiandrogens or exerting potential androgenic disruption indirectly through the inhibition of cytochrome P450 (CYP450) enzyme activity is yet an unresolved question. We herein evaluated five commonly used triazole fungicides including bitertanol, hexaconazole, penconazole, tebuconazole and uniconazole for the androgenic and anti-androgenic activity using two-hybrid recombinant human androgen receptor (AR) yeast bioassay and comparatively evaluated their effects on enzymatic activity of CYP3A4 by P450-Glo™ CYP3A4 bioassay. All five fungicides showed moderate anti-androgenic activity toward human AR with the IC₅₀ ranging from 9.34 μM to 79.85 μM. The anti-androgenic activity remained no significant change after the metabolism mediated by human liver microsomes. These fungicides significantly inhibited the activity of CYP3A4 at the environmental relevant concentrations and the potency ranks as tebuconazole > uniconazole > hexaconazole > penconazole > bitertanol with the corresponding IC₅₀ of 0.81 μM, 0.93 μM, 1.27 μM, 2.22 μM, and 2.74 μM, respectively. We found that their anti-androgenic activity and the inhibition potency toward CYP3A4 inhibition was significantly correlated (R² between 0.83 and 0.97, p < 0.001). Our results indicated that the risk assessment of triazole pesticides and structurally similar chemicals should fully consider potential androgenic disrupting effects and the influences on the activity of CYP450s.

Pesticide detection in air samples from contrasted houses and in their inhabitants' hair

In order to identify associations between indoor air contamination and human exposure to pesticides, hair samples from 14 persons (9 adults and 5 children below 12 years) were collected simultaneously with the air of their 5 contrasted houses. Three houses were situated in Alsace (France), one in Lorraine (France) and one in Luxembourg (Luxembourg). Houses were located in urban (n=3), semi-urban (n=1) and rural areas (n=1). Twenty five (25) pesticides were detected at least once in indoor air samples and 20 pesticides were detected at least once in hair samples. The comparison between hair and air samples for the same sampling periods shows that pesticides detected in the two matrices were not necessarily associated. Exposure profiles varied from one home to another but also between inhabitants of the same home, suggesting that exposure can be different between inhabitants of the same home. This study demonstrated the usefulness and the complementarity of hair analysis, for the personalized biomonitoring of people exposure to pesticides, and air analysis, for the identification of airborne exposure and house contamination.

Occurrence of biomarkers of pesticide exposure in non-invasive human specimens

Biomonitoring has been used in many types of investigations, including national programmes and epidemiological studies, to explore the occurrence of biomarkers of pesticide exposure in the general population or relevant groups. This review discusses recent studies that measure levels of biomarkers of pesticide exposure in non-invasive human specimens such as urine, breast milk, meconium and hair. Specific and non-specific metabolites of organophosphate and pyrethroid insecticides have been widely investigated in urine, where some of the suitable biomarkers present rates of detection higher than 80%, which stand for an ongoing chronic exposure to traces of these chemicals. Hair is a promising emerging matrix, but some issues on its suitability and the biological relevance needs further research. Breast milk was used in research investigations focused mainly on legacy pesticides, which provide useful information about time trends.

Characterization of cell-free extracts from fenpropathrin-degrading strain Bacillus cereus ZH-3 and its potential for bioremediation of pyrethroid-contaminated soils

Synthetic pyrethroid fenpropathrin has received increasing attention because of its environmental contamination and toxic effects on non-target organisms including human beings. Here we report the degradation characteristics of cell-free extracts from fenpropathrin-degrading strain Bacillus cereus ZH-3 and its potential for pyrethroid bioremediation in soils. 50mg·L(-1) of fenpropathrin was decreased to 20.6mg·L(-1) by the enzymatic extracts (869.4mg·L(-1)) within 30min. Kinetic constants Km and Vm were determined to be 1006.7nmol·L(-1) and 56.8nmol·min(-1), respectively. Degradation products were identified as 3-phenoxybenzaldehyde, α-hydroxy-3-phenoxy-benzeneacetonitrile and phenol by gas chromatography-mass spectrometry (GC-MS). In addition to degradation of fenpropathrin, the cell-free extracts could degrade other pyrethroids including beta-cypermethrin, cyfluthrin, deltamethrin and cypermethrin. Additionally, the reaction conditions were optimized. In the sterile and non-sterile soils, 50mg·kg(-1) of fenpropathrin was reduced to 15.3 and 13.9mg·L(-1) in 1d, respectively. Sprayed 100 and 300mg·kg(-1) of fenpropathrin emulsifiable concentrate (EC), up to 84.6% and 92.1% of soil fenpropathrin were removed from soils within 7d, respectively. Taken together, our results depict the biodegradation characteristics of cell-free extracts from B. cereus ZH-3, highlight its promising potential in bioremediation of pyrethroid-contaminated soils and also provide new insights into the utilization of degrading microbes.

In vivo and ex vivo SPME: a low invasive sampling and sample preparation tool in clinical bioanalysis

Solid phase microextraction (SPME) is well-established technology in bioanalysis. Current review discusses the features of SPME, which determine the non- or low-invasiveness of the method in biomedical analysis. In the first section we analyze the factors, which have significant influence on the SPME sampling device performance in the view of sampling safety and efficiency. In the later sections applicability of various SPME approaches for analysis of easily accessible samples routinely used for analysis (e.g., urine, blood) as well as limited availability samples (tissues) is discussed. Moreover, the examples of sampling alternative matrices such as hair, saliva, sweat or breath are presented. The advantages and limitation of the technology in the view of future development of SPME are also reviewed.

Determination of organochlorines, polychlorinated biphenyls and polybrominated diphenyl ethers in human hair: estimation of external and internal exposure

A novel method was developed for the analysis of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in human hair samples. External contaminants of hair were extracted with acetone under sonication, while washed hair was further hydrolyzed in formic acid and acetone (1:4, v/v) with microwave assisted extraction (MAE) for internal contaminant measurements. Both internal and external extracts were cleaned up with gel permeation chromatography (GPC) and then solid phase extraction (SPE), before analyzed by a large volume injection-gas chromatography-tandem mass spectrometry (LVI-GC-MS/MS) using triple quadruple mass analyzer. Good linearity (R(2)⩾ 0.996) was established within a concentration range between 0.1 and 100 ng mL(-)(1) among all target analytes. The method was validated for accuracy, precision and sensitivity. The developed method is intended to be cost effective and robust for the routine human hair analysis of PCBs, PBDEs and OCPs including acid-labile OCPs. The described method has been applied in pilot biomonitoring study and the preliminary data suggested that the contaminant profiles with the use of partial least-squares analysis discriminant analysis (PLA-DA) could be useful in differentiating external and internal exposure.

Trends in drug testing in oral fluid and hair as alternative matrices

The use of alternative matrices such as oral fluid and hair has increased in the past decades because of advances in analytical technology. However, there are still many issues that need to be resolved. Standardized protocols of sample pretreatment are needed to link the detected concentrations to final conclusions. The development of suitable proficiency testing schemes is required. Finally, interpretation issues such as link to effect, adulteration, detection markers and thresholds will hamper the vast use of these matrices. Today, several niche areas apply these matrices with success, such as drugs and driving for oral fluid and drug-facilitated crimes for hair. Once those issues are resolved, the number of applications will markedly grow in the future.

Potential mechanisms underlying response to effects of the fungicide pyrimethanil from gene expression profiling in Saccharomyces cerevisiae

Pyrimethanil is a fungicide mostly applied in vineyards. When misused, residue levels detected in grape must or in the environment may be of concern. The present work aimed to analyze mechanisms underlying response to deleterious effects of pyrimethanil in the eukaryotic model Saccharomyces cerevisiae. Pyrimethanil concentration-dependent effects at phenotypic (inhibition of growth) and transcriptomic levels were examined. For transcriptional profiling, analysis focused on two sublethal exposure conditions that inhibited yeast growth by 20% or 50% compared with control cells not exposed to the fungicide. Gene expression modifications increased with the magnitude of growth inhibition, in numbers and fold-change of differentially expressed genes and in diversity of over-represented functional categories. These included mostly biosynthesis of arginine and sulfur amino acids metabolism, as well as energy conservation, antioxidant response, and multidrug transport. Several pyrimethanil-responsive genes encoded proteins sharing significant homology with proteins from phytopathogenic fungi and ecologically relevant higher eukaryotes.