Pesticide Metabolites Research Articles

Classifying micropollutants by environmental risk in groundwater using screening analysis associated to a hybrid multicriteria method combining (Q)SAR tools, fuzzy AHP and ELECTRE

This study aimed to evaluate and monitor pesticides in groundwater of the Serra Geral aquifer, located in the Paraná Basin 3 (southern Brazil), using Liquid Chromatography coupled with a Quadrupole-Time-of-Flight Mass Spectrometer (LC-QTOF MS). A total of 117 samples, collected in three different moments, were analyzed over 36 months. Groundwater samples from 35 wells and four surface water points were monitored in each sampling campaign. A pesticide screening methodology was proposed with the tentative identification of 1607 pesticides and pesticide metabolites. The application of the proposed methodology resulted in the verification of 29 pesticides and pesticide metabolites, 7 as confirmed analytes and 22 as suspect compounds. (Q)SAR in silico predictions and GUS index calculation provided data on the potential environmental risk of the identified compounds, with eight endpoints considered. After in silico predictions, an alternative hybrid multicriteria method was applied, combining the weighting of endpoints of fuzzy AHP and micropollutants classification by environmental risk using ELECTRE. The fuzzy AHP results indicated the greatest importance of mutagenicity among the eight evaluated indicators, while the scarce influence of the physicochemical properties on the environmental risk suggested their exclusion from the model. Accordingly, the ELECTRE results highlighted the prevalence of thiamethoxam and carbendazim as the most dangerous for the environment. The application of the proposed method enabled the selection of the compounds that must be monitored, considering mutagenicity and toxicity predictions for environmental risk analysis.

The health risk of acetochlor metabolite CMEPA is associated with lipid accumulation induced liver injury

Liver injury may cause many diseases, such as non-alcoholic fatty liver disease (NAFLD). Acetochlor is one of the representative chloroacetamide herbicides, and its metabolite 2-chloro-N-(2-ethyl-6-methyl phenyl) acetamide (CMEPA) is the main form of exposure in the environment. It has been shown that acetochlor can cause mitochondrial damage of HepG2 cells and induce apoptosis by activating Bcl/Bax pathway (Wang et al., 2021). But there has been less research on CMEPA. we explored the possibility of CMEPA and liver injury through biological experiments. In vivo, CMEPA (0–16 mg/L) induced liver damage in zebrafish larvae, including increased lipid droplets, changes in liver morphology (>1.3-fold) and increased TC/TG content (>2.5-fold). In vitro, we selected L02 (human normal liver cells) as the model, and explored its molecular mechanism. We found that CMEPA (0–160 mg/L) induced apoptosis (similar to 40%), mitochondrial damage and oxidative stress in L02 cells. CMEPA induced intracellular lipid accumulation by inhibiting AMPK/ACC/CPT-1A signaling pathway and activating SREBP-1c/FAS signaling pathway. Our study provides evidence of a link between CMEPA and liver injury. This raises concerns regarding the health risks of pesticide metabolites to liver health.

Fitness assessment of Mytilus galloprovincialis Lamarck, 1819 after exposure to herbicide metabolite propachlor ESA

The lack of data on the chronic effects of chloroacetanilide herbicide metabolites on non-target aquatic organisms creates a gap in knowledge about the comprehensive impacts of excessive and repeated pesticide use. Therefore, this study evaluates the long-term effects of propachlor ethanolic sulfonic acid (PROP-ESA) after 10 (T1) and 20 (T2) days at the environmental level of 3.5 μg.L−1 (E1) and its 10x fold multiply 35 μg.L−1 (E2) on a model organism Mytilus galloprovincialis. To this end, the effects of PROP-ESA usually showed a time- and dose-dependent trend, especially in its amount in soft mussel tissue. The bioconcentration factor increased from T1 to T2 in both exposure groups – from 2.12 to 5.30 in E1 and 2.32 to 5.48 in E2. Biochemical haemolymph profile and haemocyte viability were not affected by PROP-ESA exposure. In addition, the viability of digestive gland (DG) cells decreased only in E2 compared to control and E1 after T1. Moreover, malondialdehyde levels increased in E2 after T1 in gills, and DG, superoxidase dismutase activity and oxidatively modified proteins were not affected by PROP-ESA. Histopathological observation showed several damages to gills (e.g., increased vacuolation, over-production of mucus, loss of cilia) and DG (e.g., growing haemocyte trend infiltrations, alterations of tubules). This study revealed a potential risk of chloroacetanilide herbicide, propachlor, via its primary metabolite in the Bivalve bioindicator species M. galloprovincialis. Furthermore, considering the possibility of the biomagnification effect, the most prominent threat poses the ability of PROP-ESA to be accumulated in edible mussel tissues. Therefore, future research about the toxicity of pesticide metabolites alone or their mixtures is needed to gain comprehensive results about their impacts on living non-target organisms.

Prenatal organochlorine pollutant exposure and risk of schizophrenia in a national birth cohort

Non-genetic prenatal exposures have been associated with schizophrenia risk. However, the role of prenatal exposure to environmental neurotoxicants in offspring schizophrenia risk has been studied in only limited instances. Polychlorinated biphenyls (PCBs) and the pesticide metabolite p,p′-dichlorodiphenyl dichloroethylene (DDE) have been linked to neurodevelopmental outcomes, including impairments implicated in schizophrenia. To determine whether prenatal maternal levels of organochlorine pollutants including PCBs or DDE are associated with schizophrenia in the offspring, an investigation was conducted in the Finnish Prenatal Study of Schizophrenia (FIPS-S), a case-control study nested in a national birth cohort. Cases were born in 1987–1991 and had at least two diagnoses of schizophrenia (ICD-10 F20; ICD-9 295) or schizoaffective disorder (ICD-10 F25; ICD-9 295.7) recorded in the national Care Register for Health Care. Each case was individually matched to a control on sex, date of birth, and residence in Finland on the date of case diagnosis. In 500 case-control pairs, PCB congeners 74, 99, 118, 138, 153, 156, 170, 180, 183, 187, and some widespread organochlorine pesticides or their metabolites including DDE were measured in archived prenatal maternal sera using gas chromatography - high triple quadrupole mass spectrometry. Maternal total PCBs were quantified as the sum of concentrations of the measured congeners. Associations with schizophrenia were examined using conditional logistic regression. Maternal PCB or DDE levels greater than the 75th percentiles of the control distributions showed no evidence of association with offspring schizophrenia (PCBs: adjusted odds ratio (aOR) = 1.13, 95 % CI = 0.85–1.50), p = 0.41; DDE: aOR = 1.08, 95 % CI = 0.80–1.45; p = 0.63). Maternal levels of either pollutant dichotomized at the 90th percentile or considered as a continuous variable also did not show evidence for association with offspring schizophrenia. This study found a lack of evidence that prenatal maternal levels of the organochlorine pollutants DDE and PCBs are associated with offspring risk of schizophrenia.

Factors affecting urinary organophosphate pesticide metabolite levels among Californian agricultural community members

Organophosphate (OP) pesticides are widely used in California for agricultural pest and weed control despite their well-documented adverse health effects among infants, children, and adults. We sought to identify factors affecting urinary OP metabolites among families living in high-exposure communities. Our study included 80 children and adults who lived within 61 m (200 ft) of agricultural fields in the Central Valley of California in January and June 2019, which are pesticide non-spraying and spraying seasons, respectively. We collected one urine sample per participant during each visit to measure dialkyl phosphate (DAP) metabolites; these were coupled with in-person surveys to identify health, household, sociodemographic, pesticide exposure, and occupational risk factors. We used a data-driven, best subsets regression approach to identify key factors that influenced urinary DAPs. Participants were mostly Hispanic/Latino(a) (97.5 %), over half were female (57.5 %), and most households reported having a member who worked in agriculture (70.6 %). Among the 149 urine samples suitable for analysis, DAP metabolites were detected in 48.0 % and 40.5 % of samples during January and June, respectively. Total diethyl alkylphosphates (EDE) were only detected in 4.7 % (n = 7) of samples, but total dimethyl alkylphosphates (EDM) were detected in 41.6 % (n = 62) of samples. No differences were observed in urinary DAP levels by visit month or by occupational exposure to pesticides. Best subsets regression identified several individual- and household-level variables that influenced both urinary EDM and total DAPs: the number of years spent living at the current address, household use of chemical products to control mice/rodents, and seasonal employment status. Among adults only, we identified educational attainment (for total DAPs) and age category (for EDM) as significant factors. Our study found consistent urinary DAP metabolites among participants, regardless of spraying season, and identified potential mitigating factors that members of vulnerable populations can implement to protect their health against OP exposure.

Individual and combined toxicity of sulfamethoxazole and desethylatrazine to Chlorella vulgaris: growth inhibition, photosynthetic activity and oxidative stress

ABSTRACT The influence of emerging contaminants on the composition of aquatic ecosystems, including antibiotics and pesticide metabolites, is receiving increasing attention. In this study, the acute and chronic toxic effects of single and combined exposure to sulfamethoxazole (SMX) and desethylatrazine (DEA) on Chlorella vulgaris (C. vulgaris) were evaluated in terms of growth, pigment content and antioxidant systems. The findings demonstrated that cytochrome content and cell growth followed a similar trend for both single and combined exposures, with C. vulgaris being affected in a dose-dependent manner, and chlorophyll content decreasing at high exposures. For SMX and DEA, the maximum inhibition rates at a single exposure were 95.14% and 87.31%, respectively. Cell membrane permeability, superoxide dismutase content and catalase release were significantly increased in the early stages of cultivation. Additionally, cell density was used to calculate the single exposure half effect concentration (EC50), which was then used as part of the toxic unit (TU) method for evaluating mixture interactions. TU analysis revealed that the interaction between SMX and DEA shifted from being synergistic to being antagonistic after 7 d of incubation. These results suggest that SMX and DEA may play a significant role in aquatic ecosystems.

Influence of exposure to pesticides on telomere length and pregnancy outcome: Diethylphosphates but not Dimethylphosphates are associated with accelerated telomere attrition in a Palestinian cohort

Exposure to environmental pesticides during pregnancy is associated with adverse health outcomes such as low birth weight and impaired neuro-development. In this study, we assessed maternal leukocyte telomere lengths (TL) in Palestinian pregnant women and compared the data with urinary organophosphate concentrations, demographic, lifestyle and dietary factors, birth weight, body length, gestational age, and head circumference. Women with high urine levels of creatinine adjusted diethylphosphate(DE)derived pesticide metabolites DEP, DETP or DEDTP had shorter telomeres (p = 0.05). Women living in proximity to agricultural fields had shorter telomeres compared to women not living in proximity to agricultural fields (p = 0.011). Regular consumption of organic food was associated with shorter telomeres (p = 0.01), whereas the consumption of other vegetables such as artichokes was rather associated with longer telomeres. By contrast, urine levels of dimethylphosphate(DM)-derived pesticide metabolites DMTP and DMDTP were associated with lower birth weight (p = 0.05) but not with shrter telomeres. In conclusion organophosphate pesticides and living in proximity to agriculture are associated with shorter TL, likely due to higher consumption of contaminated fruits and vegetables and/or the transport of pesticides to non-treatment sites. DE and DM substituted pesticides seem to have different effects on telomeres and development.

LC–Tof-Ms an Influential Hyphenated Technique and its Application

LC-TOF-MS is powerful analytical technique. It is a combination of two techniques one of which is belongs to chromatography and other is from spectroscopy. Chromatography is separation technique and perform both techniques separately it is very time consuming but combined both techniques to save time and provide better results. This represents the potential of liquid chromatography with (quadrupole) time-of-flight mass spectrometry [LC-(Q)TOF-MS] in examining the presence of pesticide metabolites in food and water samples. This method portrays a quick enhanced screen for blood and urine specimens in post-mortem, driving under the influence and drug facilitated sexual assault forensic toxicology casework. (LC–MS) is an analytical technique that amalgamate the physical separation capability of liquid chromatography with the mass analysis capability of mass-spectrometry (MS).This technique can be used in analysis of pharmacokinetics, proteomics/metabolomics, development drug, analysis of pesticides in vegetables, analysis of medicinal panaxherbs for metabolomic research, identification of diphenhydramine in segment sample, investigation of pesticides metabolites in food and water etc.

Quantification and stability assessment of urinary phenolic and acidic biomarkers of non-persistent chemicals using the SPE-GC/MS/MS method

Nowadays, people are exposed to numerous man-made chemicals, many of which are ubiquitously present in our daily lives, and some of which can be hazardous to human health. Human biomonitoring plays an important role in exposure assessment, but complex exposure evaluation requires suitable tools. Therefore, routine analytical methods are needed to determine several biomarkers simultaneously. The aim of this study was to develop an analytical method for quantification and stability testing of 26 phenolic and acidic biomarkers of selected environmental pollutants (e.g., bisphenols, parabens, pesticide metabolites) in human urine. For this purpose, a solid-phase extraction coupled with gas chromatography and tandem mass spectrometry (SPE-GC/MS/MS) method was developed and validated. After enzymatic hydrolysis, urine samples were extracted using Bond Elut Plexa sorbent, and prior to GC, the analytes were derivatized with N-trimethylsilyl-N-methyl trifluoroacetamide (MSTFA). Matrix-matched calibration curves were linear in the range of 0.1–1000 ng mL−1 with R > 0.985. Satisfactory accuracy (78–118%), precision (< 17%), and limits of quantification (0.1–0.5 ng mL−1) were obtained for 22 biomarkers. The stability of the biomarkers in urine was assayed under different temperature and time conditions that included freezing and thawing cycles. All tested biomarkers were stable at room temperature for 24 h, at 4 °C for 7 days, and at −20 °C for 18 months. The total concentration of 1-naphthol decreased by 25% after the first freeze–thaw cycle. The method was successfully used for the quantification of target biomarkers in 38 urine samples.

The metabolism and dissipation behavior of tolfenpyrad in tea: A comprehensive risk assessment from field to cup

The metabolites of pesticides usually require rational risk assessment. In the present study, the metabolites of tolfenpyrad (TFP) in tea plants were identified using UPLC-QToF/MS analysis, and the transfer of TFP and its metabolites from tea bushes to consumption was studied for a comprehensive risk assessment. Four metabolites, PT-CA, PT-OH, OH-T-CA, and CA-T-CA, were identified, and PT-CA and PT-OH were detected along with dissipation of the parent TFP under field conditions. During processing, 3.11–50.00 % of TFP was further eliminated. Both PT-CA and PT-OH presented a downward trend (7.97–57.89 %) during green tea processing but an upward trend (34.48–124.17 %) during black tea manufacturing. The leaching rate (LR) of PT-CA (63.04–101.03 %) from dry tea to infusion was much higher than that of TFP (3.06–6.14 %). As PT-OH was no longer detected in tea infusions after 1 d of TFP application, TFP and PT-CA were taken into account in the comprehensive risk assessment. The risk quotient (RQ) assessment indicated a negligible health risk, but PT-CA posed a greater potential risk than TFP to tea consumers. Therefore, this study provides guidance for rational TFP application and suggests the sum of TFP and PT-CA residues as the maximum residual limit (MRL) in tea.

The metabolic processes of selected pesticides and their influence on plant metabolism. A case study of two field-cultivated wheat varieties

Pesticides that are absorbed by plants undergo biotransformation and might affect plant metabolic processes. The metabolisms of two cultivated wheat varieties, Fidelius and Tobak, treated with commercially available fungicides (fluodioxonil, fluxapyroxad, and triticonazole) and herbicides (diflufenican, florasulam, and penoxsulam) were studied under field conditions. The results provide novel insights regarding the effects of these pesticides on plant metabolic processes. Plants (roots and shoots) were sampled six times during the six-week experiment. Pesticides and pesticide metabolites were identified using GC–MS/MS, LC–MS/MS, and LC–HRMS, while root and shoot metabolic fingerprints were determined using non-targeted analysis. Fungicide dissipation kinetics were analyzed according to the quadratic mechanism (R2: 0.8522–0.9164) for Fidelius roots, and zero-order for Tobak roots (R2: 0.8455–0.9194); shoot dissipation kinetics were analyzed according to first-order (R2: 0.9593–0.9807) and quadratic (R2: 0.8415–0.9487) mechanisms for Fidelius and Tobak, respectively. The fungicide degradation kinetics were different compared to reported literature values, most likely due to differences in pesticide application methods. The following metabolites were respectively identified in shoot extracts of both wheat varieties for fluxapyroxad, triticonazole, and penoxsulam: 3-(difluoromethyl)-N-(3',4',5'-trifluorobiphenyl-2-yl)-1H pyrazole-4-carboxamide, 2-chloro-5-{(E)-[2-hydroxy-3,3-dimethyl-2-(1H-1,2,4-triazol-1-ylmethyl)-cyclopentylidene]-methyl}phenol, and N-(5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidin-2-yl)-2,4-dihydroxy-6 (trifluoromethyl)benzene sulfonamide. Metabolite dissipation kinetics varied depending on the wheat variety. These compounds were more persistent than parent compounds. Despite having the same cultivation conditions, the two wheat varieties varied in their metabolic fingerprints. The study revealed that pesticide metabolism has a greater dependence on plant variety and method of administration compared to the physicochemical properties of the active substance. This highlights the necessity of conducting research on pesticide metabolism under field conditions.

Exposure to non-persistent pesticides and sexual maturation of Spanish adolescent males

BackgroundSeveral non-persistent pesticides are endocrine disrupting chemicals and may impact on sexual maturation. ObjectiveTo examine the association between urinary biomarkers of non-persistent pesticides and sexual maturation in adolescent males in the Environment and Childhood (INMA) Project. MethodsThe metabolites of several pesticides were measured in spot urine samples collected from 201 boys aged 14–17 years, including: 3,5,6-trichloro-2-pyridinol (TCPy), metabolite of chlorpyrifos; 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPy), metabolite of diazinon; malathion diacid (MDA), metabolite of malathion; diethyl thiophosphate (DETP) and diethyl dithiophosphate, non-specific metabolites of organophosphates; 3-phenoxybenzoic acid (3-PBA) and dimethyl cyclopropane carboxylic acid, metabolites of pyrethroids; 1-naphthol (1-NPL), metabolite of carbaryl; and ethylene thiourea (ETU), metabolite of dithiocarbamate fungicides. Sexual maturation was assessed using Tanner stages, self-reported Pubertal Development Scale, and testicular volume (TV). Multivariate logistic regression was employed to examine associations between urinary pesticide metabolites and the odds of being in Tanner stage 5 of genital development (G5) or pubic hair growth (PH5); stage ≥4 of overall pubertal development, gonadarche, and adrenarche; or having mature TV (≥25 mL). ResultsDETP concentrations>75th percentile (P75) were associated with lower odds of being in stage G5 (OR = 0.27; 95% CI = 0.10–0.70), detectable TCPy with lower odds of gonadal stage≥4 (OR = 0.50; 95% CI = 0.26–0.96), and intermediate detectable MDA concentrations (<P75) with lower odds of adrenal stage≥4 (OR = 0.32; 95% CI = 0.11–0.94). Conversely, detectable concentrations of 1-NPL were associated with higher odds of adrenal stage≥4 (OR = 2.61; 95% CI = 1.30–5.24) but lower odds of mature TV (OR = 0.42; 95% CI = 0.19–0.90). ConclusionExposure to certain pesticides may be associated with delayed sexual maturity in adolescent males.

Assessment of exposure to pesticide mixtures in five European countries by a harmonized urinary suspect screening approach.

Humans are exposed to a mixture of pesticides through diet as well as through the environment. We conducted a suspect-screening based study to describe the probability of (concomitant) exposure to a set of pesticide profiles in five European countries (Latvia, Hungary, Czech Republic, Spain and the Netherlands). We explored whether living in an agricultural area (compared to living in a peri-urban area), being a a child (compared to being an adult), and the season in which the urine sample was collected had an impact on the probability of detection of pesticides (-metabolites). In total 2088 urine samples were collected from 1050 participants (525 parent-child pairs) and analyzed through harmonized suspect screening by five different laboratories. Fourty pesticide biomarkers (either pesticide metabolites or the parent pesticides as such) relating to 29 pesticides were identified at high levels of confidence in samples across all study sites. Most frequently detected were biomarkers related to the parent pesticides acetamiprid and chlorpropham. Other biomarkers with high detection rates in at least four countries related to the parent pesticides boscalid, fludioxonil, pirimiphos-methyl, pyrimethanil, clothianidin, fluazifop and propamocarb. In 84% of the samples at least two different pesticides were detected. The median number of detected pesticides in the urine samples was 3, and the maximum was 13 pesticides detected in a single sample. The most frequently co-occurring substances were acetamiprid with chlorpropham (in 62 urine samples), and acetamiprid with tebuconazole (30 samples). Some variation in the probability of detection of pesticides (-metabolites) was observed with living in an agricultural area or season of urine sampling, though no consistent patterns were observed. We did observe differences in the probability of detection of a pesticide (metabolite) among children compared to adults, suggesting a different exposure and/or elimination patterns between adults and children. This survey demonstrates the feasibility of conducting a harmonized pan-European sample collection, combined with suspect screening to provide insight in the presence of exposure to pesticide mixtures in the European population, including agricultural areas. Future improvements could come from improved (harmonized) quantification of pesticide levels.

Determination of phenoxyacetic herbicides, metabolites of organophosphorus and pyrethroid pesticides in human urine using solid phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry

Pesticides are widely used in most agricultural areas to protect food crops but adversely affect ecosystems and human beings. Pesticides have attracted great public concern due to their toxic properties and ubiquitous occurrence in the environment. China is one of the largest users and producers of pesticides globally. However, limited data are available on pesticide exposure in humans, which warrants a method for quantification of pesticides in human samples. In the present study, we validated and developed a comprehensive and sensitive method for the quantification of two phenoxyacetic herbicides, two metabolites of organophosphorus pesticides and four metabolites of pyrethroid pesticides in human urine using 96-well plate solid phase extraction (SPE) coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). For this purpose, a systematic optimization of the chromatographic separation conditions and MS/MS parameters was conducted. Six solvents were optimized for the extraction and clean-up of human urine samples. The targeted compounds in the human urine samples were well separated within 16 min in one analytical run. A 1 mL aliquot of human urine sample was mixed with 0.5 mL sodium acetate buffer (0.2 mol/L) and hydrolyzed by β-glucuronidase enzyme at 37 ℃ overnight. The eight targeted analytes were extracted and cleaned using an Oasis HLB 96-well solid phase plate and eluted with methanol. The separation of the eight target analytes was performed on a UPLC Acquity BEH C18 column (150 mm×2.1 mm, 1.7 μm) with gradient elution using 0.1% (v/v) acetic acid in acetonitrile and 0.1% (v/v) acetic acid in water. The analytes were identified using the multiple reaction monitoring (MRM) mode under negative electrospray ionization (ESI-) and quantified by isotope-labelled analogs. Para-nitrophenol (PNP), 3,5,6-tricholor-2-pyridinol (TCPY) and cis-dichlorovinyl-dimethylcyclopropane carboxylic acid (cis-DCCA) exhibited good linearities ranging from 0.2 to 100 μg/L, and 3-phenoxy benzoic acid (3-PBA), 4-fluoro-3-phenoxy benzoic acid (4F-3PBA), 2,4-dicholorphenoxyacetic acid (2,4-D), trans-dichlorovinyl-dimethylcyclopropane carboxylic acid (trans-DCCA) and 2,4,5-tricholorphenoxyacetic acid (2,4,5-T) showed linearity ranging from 0.1 to 100 μg/L with correlation coefficients all above 0.9993. Method detection limits (MDLs) and method quantification limits (MQLs) of targeted compounds were in the range of 0.02 to 0.07 μg/L and 0.08 to 0.2 μg/L, respectively. The spiked recoveries of target compounds at three levels of 0.5, 5 and 40 μg/L were 91.1% to 110.5%. The inter- and intra-day precisions of targeted analytes were 2.9% to 7.8% and 6.2% to 10%, respectively. This method was applied to the analysis of 214 human urine samples across China. The results showed that all the targeted analytes, except 2,4,5-T, were detected in human urine. The detection rates of TCPY, PNP, 3-PBA, 4F-3PBA, trans-DCCA, cis-DCCA, and 2,4-D were 98.1%, 99.1%, 94.4%, 2.80%, 99.1%, 63.1% and 94.4%, respectively. The median concentration of targeted analytes in a decreasing order were: 2.0 μg/L (TCPY), 1.8 μg/L (PNP), 0.99 μg/L (trans-DCCA), 0.81 μg/L (3-PBA), 0.44 μg/L (cis-DCCA), 0.35 μg/L (2,4-D) and below MDLs (4F-3PBA ). For the first time, we developed a method to extract and purify specific biomarkers of pesticides from human samples based on offline 96-well SPE. This method has the advantages of simple operation, high sensitivity, and high accuracy. Moreover, up to 96 human urine samples were analyzed in one batch. It is suitable for the determination of eight specific pesticides and their metabolites in large sample sizes.

Childhood exposure to non-persistent endocrine disrupting chemicals and multi-omic profiles: A panel study

BackgroundIndividuals are exposed to environmental pollutants with endocrine disrupting activity (endocrine disruptors, EDCs) and the early stages of life are particularly susceptible to these exposures. Previous studies have focused on identifying molecular signatures associated with EDCs, but none have used repeated sampling strategy and integrated multiple omics. We aimed to identify multi-omic signatures associated with childhood exposure to non-persistent EDCs. MethodsWe used data from the HELIX Child Panel Study, which included 156 children aged 6 to 11. Children were followed for one week, in two time periods. Twenty-two non-persistent EDCs (10 phthalate, 7 phenol, and 5 organophosphate pesticide metabolites) were measured in two weekly pools of 15 urine samples each. Multi-omic profiles (methylome, serum and urinary metabolome, proteome) were measured in blood and in a pool urine samples. We developed visit-specific Gaussian Graphical Models based on pairwise partial correlations. The visit-specific networks were then merged to identify reproducible associations. Independent biological evidence was systematically sought to confirm some of these associations and assess their potential health implications. Results950 reproducible associations were found among which 23 were direct associations between EDCs and omics. For 9 of them, we were able to find corroborating evidence from previous literature: DEP - serotonin, OXBE - cg27466129, OXBE - dimethylamine, triclosan - leptin, triclosan - serotonin, MBzP - Neu5AC, MEHP - cg20080548, oh-MiNP - kynurenine, oxo-MiNP − 5-oxoproline. We used these associations to explore possible mechanisms between EDCs and health outcomes, and found links to health outcomes for 3 analytes: serotonin and kynurenine in relation to neuro-behavioural development, and leptin in relation to obesity and insulin resistance. ConclusionsThis multi-omics network analysis at two time points identified biologically relevant molecular signatures related to non-persistent EDC exposure in childhood, suggesting pathways related to neurological and metabolic outcomes.

Unified Method for Target and Non-Target Monitoring of Pesticide Residues in Fruits and Fruit Juices by Gas Chromatography-High Resolution Mass Spectrometry.

A new polyvalent wide-scope analytical method, valid for both raw and processed (juices) fruits, combining target and non-target strategies, has been developed and validated to determine low concentrations of 260 pesticides, as well as many potential non-target substances and metabolites. The target approach has been validated according to SANTE Guide requirements. Trueness, precision, linearity, and robustness values were validated in raw fruit (apple) and juice (apple juice) as representative solid and liquid food commodities. Recoveries were between 70-120% and two ranges of linearity were observed: 0.5-20 μg kg-1 (0.5-20 μg L-1 apple juice) and 20-100 μg kg-1 (20-100 μg L-1 apple juice). The limits of quantification (LOQs) reached were lower than 0.2 μg kg-1 in apple (0.2 μg L-1 apple juice) in most cases. The developed method, based on QuEChERS extraction followed by gas chromatography-high resolution mass spectrometry (GC-HRMS), achieves part-per-trillions lower limits, which allowed the detection of 18 pesticides in commercial samples. The non-target approach is based on a retrospective analysis of suspect compounds, which has been optimized to detect up to 25 additional compounds, increasing the scope of the method. This made it possible to confirm the presence of two pesticide metabolites which were not considered in the target screening, phtamlimide and tetrahydrophthalimide.

Pesticide Residues and Metabolites in Greek Honey and Pollen: Bees and Human Health Risk Assessment.

Bees encounter a plethora of environmental contaminants during nectar and pollen collection from plants. Consequently, after their entrance into the beehives, the transfer of numerous pollutants to apicultural products is inevitable. In this context, during the period of 2015-2020, 109 samples of honey, pollen, and beebread were sampled and analyzed for the determination of pesticides and their metabolites. More than 130 analytes were investigated in each sample by applying two validated multiresidue methods (HPLC-ESI-MS/MS and GC-MS/MS). Until the end of 2020, 40 determinations were reported in honey, resulting in a 26% positive to at least one active substance. The concentrations of pesticides ranged from 1.3 ng/g to 785 ng/g honey. For seven active substances in honey and pollen, maximum residue limits (MRLs) exceedances were observed. Coumaphos, imidacloprid, acetamiprid, amitraz metabolites (DMF and DMPF), and tau-fluvalinate were the predominant compounds detected in honey, while several pyrethroids such as λ-cyhalothrin, cypermethrin, and cyfluthrin were also found. Pollen and beebread, as expected, accumulated a higher number of active substances and metabolites (32 in total), exhibiting almost double the number of detections. Although the above findings verify the occurrence of numerous pesticide and metabolite residues in both honey and pollen, the human risk assessment in the majority of the cases does not raise any concerns, and the same applies to bee risk assessment.

Engineering of a phosphotriesterase with improved stability and enhanced activity for detoxification of the pesticide metabolite malaoxon.

Organophosphorus (OP) pesticides are still widely applied but pose a severe toxicological threat if misused. For in vivo detoxification, the application of hydrolytic enzymes potentially offers a promising treatment. A well-studied example is the phosphotriesterase of Brevundimonas diminuta (BdPTE). Whereas wild-type BdPTE can hydrolyse pesticides like paraoxon, chlorpyrifos-oxon and mevinphos with high catalytic efficiencies, kcat/KM >2×107M-1min-1, degradation of malaoxon is unsatisfactory (kcat/KM ≈ 1×104M-1min-1). Here, we report the rational engineering of BdPTE mutants with improved properties and their efficient production in Escherichia coli. As result, the mutant BdPTE(VRNVVLARY) exhibits 37-fold faster malaoxon hydrolysis (kcat/KM = 4.6×105M-1min-1), together with enhanced expression yield, improved thermal stability and reduced susceptibility to oxidation. Therefore, this BdPTE mutant constitutes a powerful candidate to develop a biocatalytic antidote for the detoxification of this common pesticide metabolite as well as related OP compounds.

Comprehensive evaluation of chiral penflufen metabolite (penflufen-3-hydroxy-butyl): Identification, synthesis, enantioseparation, toxicity and enantioselective metabolism

Identification and evaluations of pesticide metabolites are necessary for risk assessment and toxicological research. In this study, the metabolites of penflufen (a widely used chiral pesticide) in rat liver microsomes were identified using liquid chromatography Q-Exactive Plus mass spectrometry. In total, 17 penflufen metabolites were identified, and most of them were hydroxylation products, which were generated by oxygenation at different candidate sites of penflufen. The relative abundance of metabolite M12 (penflufen-3-hydroxy-butyl, 32 %) was the largest, followed by M8 (15.6 %) and M2 (12.8 %). The major metabolite penflufen-3-hydroxy-butyl was first synthesized by 11 reactions with a 99.73 % purity. The absolute configuration of M12 enantiomers were confirmed after preparing enantiomers, and establishing the enantioseparation method. The M12 enantiomers toxicity to Danio rerio (LC50, >10 mg/L) and four kinds of phytopathogens (EC50, 148–34969 mg/L) were significantly lower than parents (LC50, 0.449–24.3 mg/L; EC50, 0.027–92.0 mg/L). In rat liver microsomes, approximately 40–47 % of the penflufen enantiomers were metabolized to M12 enantiomers, and R-penflufen was preferentially metabolized. The generation concentrations of S-M12 were higher than R-M12 after 10 min, and the metabolic half-lives of R-M12 (29.0–32.5 min) were shorter than S-M12 (35.2–38.1 min), and were approximately 4 times longer than parent penflufen enantiomers (4.5–9.5 min). Simultaneously, the generated contents (relative contents) of M8 (27.1–57 %) and M10 (2.22–8.36 %) from S-penflufen were lower than those from R-penflufen (M8, 24.7–92.4 %; M10, 27.4–69.5 %). The enantioselective evaluations of M12, M10 and M8 deserve further study. These findings were helpful in understanding the fate and risks of chiral penflufen.

Kisspeptin as potential biomarker of environmental chemical mixture effect on reproductive hormone profile: A pilot study in adolescent males

BackgroundKisspeptin has been proposed as an effect biomarker to understand the mechanisms by which some environmental chemicals adversely affect the human reproductive system. ObjectiveTo ascertain whether kisspeptin serum protein and DNA methylation levels are associated with exposure to several environmental chemicals (individually and as a mixture) and serum reproductive hormone levels in adolescent males. MethodsThree phenols (bisphenol A [BPA], methyl-paraben [MPB], and benzophenone-3 [BP3]); two toxic metals (arsenic and cadmium); and four metabolites of non-persistent pesticides, including insecticides (2-isopropyl-6-methyl-4-pyrimidinol [IMPy], malathion diacid [MDA], and dimethylcyclopropane carboxylic acid [DCCA]) and fungicides (ethylene thiourea [ETU]) were measured in first-morning urine samples of 133 adolescent males aged 15–17 years from the INMA-Granada cohort. In blood samples collected on the same day, KISS1 gene DNA methylation was measured at four CpGs from the Exon IV, as well as serum levels of kiss54 protein, total testosterone (T), estradiol (E2), sex hormone binding-globulin, dehydroepiandrosterone sulfate, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Multiple linear regression and mixture (quantile g-computation) models were fit. ResultsUrinary MDA and DCCA concentrations were associated with higher kiss54 levels [% change (95%CI) for each log-unit increase in concentration = 2.90 (0.32;5.56), and 1.93 (0.45,3.43), respectively]; IMPy with lower DNA methylation percentage at CpG1 and total CpGs [% change (95%CI) = −1.15 (−1.96;-0.33): −0.89 (−1.73;-0.01), respectively]; and BP3 and DCCA with lower total CpGs methylation [−0.53 (−1.04;-0.01) and − 0.69 (−1.37;-0.01), respectively]. The pesticide mixture and the whole chemical mixture were associated with higher kiss54 [% change (95%CI) = 9.09 (3.29;15.21) and 11.61 (3.96;19.82), respectively] and lower methylation levels at several CpGs. Additionally, serum kiss54 in the third tertile was associated with higher LH levels [% change (95%CI) = 28.69 (3.75–59.63)], and third-tertile CpG1, CpG2, and total CpG methylation percentages were associated with lower FSH and E2. ConclusionThe findings of the present study and the negative correlation between serum kiss54 levels and KISS1 DNA methylation percentages suggested that kisspeptin may be a promising effect biomarker.