Health risk assessment of exposure to chlorpyrifos in pregnant women using deterministic and probabilistic approaches

Longitudinal Study and Predictive Modeling of Urinary Pesticide Metabolite Concentrations in Residents of Guangzhou, China

Continuous human biomonitoring and predictive modelling of urinary pesticide metabolites are critical for evaluating pesticide exposure trends and associated health risks. We conducted repeat cross-sectional surveys to determine the urinary concentrations of eight pesticide metabolites in the residents of Guangzhou, China, from 2018 to 2022. We longitudinally analyzed the changes in these metabolite concentrations over the years and assessed the potential non-carcinogenic risks by calculating the hazard quotient and hazard index. No significant differences were observed in the total urinary pesticide metabolite concentrations over the 5 years (9.16 to 12.99 μg/L). The urinary concentrations of 3,5,6-trichloro-2-pyridinol and 2,4-dichlorophenoxyacetic acid reached their lowest levels in 2020 (1.47 and 0.11 μg/L). Conversely, urinary para-nitrophenol concentrations exhibited an inverse trend, peaking in 2020 (6.16 μg/L). The composition profiles of urinary pesticide metabolites showed that para-nitrophenol consistently constituted the largest proportion each year. Males consistently showed higher median concentrations of total urinary pesticide metabolites and individual metabolites of 3,5,6-trichloro-2-pyridinol, trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid, and para-nitrophenol than females. The concentrations of cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid in adults' urine were significantly higher than those in minors' urine each year. The total pesticide metabolite concentrations in adults' urine were significantly higher than those in minors' urine in 2018 and 2020, whereas no significant differences were observed in other years. No significant differences in urinary pesticide metabolite concentrations were observed among different BMI groups. Results showed that 14.17% of the population had hazard index values above 1, indicating a higher risk of health hazards. Three predictive models were employed to predict urinary pesticide metabolite concentrations for 2023-2024, revealing an increasing trend in 3,5,6-trichloro-2-pyridinol concentrations while other metabolites are expected to decrease. The study showed the concentration of para-nitrophenol peaked in 2020 while 3,5,6-trichloro-2-pyridinol and 2,4-dichlorophenoxyacetic acid reached their lowest levels, suggests that the COVID-19 pandemic may have influenced pesticide exposure patterns.

Deciphering molecular basis of pesticide-induced recurrent pregnancy loss: insights from transcriptomics analysis

Recent studies have revealed a notable connection between pesticide exposure and Recurrent Pregnancy Loss (RPL), yet the precise molecular underpinning of this toxicity remains elusive. Through the alignment of Differentially Expressed Genes (DEGs) of healthy and RPL patients with the target genes of 9 pesticide components, we identified a set of 12 genes responsible for RPL etiology. Interestingly, biological process showed that besides RPL, those 12 genes also associated with preeclampsia and cardiovascular disease. Enrichment analysis showed the engagement of these genes associated with essential roles in the molecular transport of small molecules, as well as the aldosterone-regulated sodium reabsorption, endocrine and other factor-regulated calcium reabsorption, mineral absorption, ion homeostasis, and ion transport by P-type ATPases. Notably, the crosstalk targets between pesticide components played crucial roles in influencing RPL results, suggesting a role in attenuating pesticide agents that contribute to RPL. It is important to note that non-significant concentration of the pesticide components observed in both control and RPL samples should not prematurely undermine the potential for pesticides to induce RPL in humans. This study emphasizes the complexity of pesticide induced RPL and highlights avenues for further research and precautionary measures.

The situation of chlorpyrifos in Mexico: a case study in environmental samples and aquatic organisms

Chlorpyrifos (CPF) is one of the most commonly used organophosphate pesticides. Because CPF was described as a toxic compound without safe levels of exposure for children, certain countries in Latin America and the European Union have banned or restricted its use; however, in Mexico it is used very frequently. The aim of this study was to describe the current situation of CPF in Mexico, as well as its use, commercialization, and presence in soil, water, and aquatic organisms in an agricultural region of Mexico. Structured questionnaires were applied to pesticide retailers to determine the sales pattern of CPF (ethyl and methyl); in addition, monthly censuses were conducted with empty pesticide containers to assess the CPF pattern of use. Furthermore, samples of soil (48 samples), water (51 samples), and fish (31 samples) were collected, which were analyzed chromatographically. Descriptive statistics were performed. The results indicate that CPF was one of the most sold (3.82%) and employed OP (14.74%) during 2021. Only one soil sample was found above the CPF limit of quantification (LOQ); in contrast, all water samples had CPF levels above the LOQ (x̄ = 4614.2 ng/L of CPF). In the case of fish samples, 6.45% demonstrated the presence of methyl-CPF. In conclusion, the information obtained in this study indicates the need for constant monitoring in the area, since the presence of CPF in soil, water, and fish constitutes a threat to the health of wildlife and humans. Therefore, CPF should be banned in Mexico to avoid a serious neurocognitive health problem.

Risk Assessment Considering the Bioavailability of 3-β-d-Glucosides of Deoxynivalenol and Nivalenol through Food Intake in Korea

Deoxynivalenol and nivalenol are major type B trichothecenes and the most frequently occurring mycotoxins worldwide. Their 3-β-d-glucoside forms have recently become a safety management issue. These glucoside conjugates are converted back to the parent toxins during human digestion, but studies to confirm their bioavailability are lacking. In this study, a risk assessment was performed considering the bioavailability of glucoside conjugates. A literature review was conducted to compile the existing bioavailability studies of glucoside conjugates, and three exposure scenarios considering bioavailability were established. As a result of a risk assessment using deterministic and probabilistic methods, both the deoxynivalenol and nivalenol groups had safe levels of tolerable daily intake percentage (TDI%), not exceeding 100%. The TDI% for the nivalenol group was approximately 2-3 times higher than that for the deoxynivalenol group. Notably, infants showed higher TDI% than adults for both toxin groups. By food processing type, the overall TDI% was highest for raw material, followed by simple-processed and then fermented-processed. Since glucoside conjugates can be converted into parent toxins during the digestion process, a risk assessment considering bioavailability allows the more accurate evaluation of the risk level of glucoside conjugates and can direct their safety management in the future.

Benchmark Dose Approach to DNA and Liver Damage by Chlorpyrifos and Imidacloprid in Male Rats: The Protective Effect of a Clove-Oil-Based Nanoemulsion Loaded with Pomegranate Peel Extract

Pesticides are widely used around the world to increase crop production. They also have negative impacts on animals, humans, and the ecosystem. This is the first report evaluating a novel pomegranate-extract-loaded clove-oil-based nanoemulsion (PELCN) and its potential for reducing oxidative stress and DNA damage, as well as its hepatoprotective effects against imidacloprid (IM) and chlorpyrifos (CPF) toxicity in male rats. The benchmark dose (BMD) approach was also used to study the dose-response toxicity of IM and CPF. IM and CPF were administered daily for 28 days at doses of 14, 28, and 54 mg/kg body weight (bw) of IM and 1, 2, and 4 mg/kg bw of CPF via drinking water. The PELCN was administered orally at a dose of 50 mg/kg bw/day of pomegranate extract, 500 mg/kg bw of the clove oil nanoemulsion, and IM or CPF at high doses in the drinking water. In male rats, IM and CPF caused a reduction in body weight gain and hepatotoxic effects as evidenced by increases in the liver enzymes AST, ALT, and ALP. They caused oxidative damage in the liver of male rats as indicated by the decreased liver activity of the GST, GPX, SOD, and CAT enzymes and decreased serum TAC. IM and CPF produced a significant dose-dependent increase in DNA damage in hepatocyte cells, resulting in moderate to severe liver damage with cells that are more inflammatory and have enlarged sinusoids and compacted nuclei. IM had a higher BMD than CPF for both body and liver weight, suggesting that CPF was more dose-dependently toxic than IM. Albumin was a highly sensitive liver biomarker for IM, while total protein was a biomarker for the CPF-treated rats. GPx was an extremely sensitive biomarker of oxidative stress in the IM treatment, while CAT and GPx were highly sensitive parameters in the CPF-treated rats. Therefore, at comparable doses, CPF has a higher potential to cause liver damage and oxidative stress than IM. The hepatotoxicity of IM and CPF can be mitigated by administering a nanoemulsion containing clove oil and pomegranate extract. The nanoemulsion acts as a protector against the oxidative stress caused by these insecticides, especially at high doses. The nanoemulsion based on clove oil increases the bioavailability and stability of the pomegranate extract, which has antioxidant properties.

Chronic Exposure to Chlorpyrifos Damages Thyroid Activity and Imbalances Hepatic Thyroid Hormones Signaling and Glucose Metabolism: Dependency of T3-FOXO1 Axis by Hyperglycemia

Early life exposure to Endocrine Disruptor Chemicals (EDCs), such as the organophosphate pesticide Chlorpyrifos (CPF), affects the thyroid activity and dependent process, including the glucose metabolism. The damage of thyroid hormones (THs) as a mechanism of action of CPF is underestimated because the studies rarely consider that TH levels and signaling are customized peripherally. Here, we investigated the impairment of metabolism/signaling of THs and lipid/glucose metabolism in the livers of 6-month-old mice, developmentally and lifelong exposed to 0.1, 1, and 10 mg/kg/die CPF (F1) and their offspring similarly exposed (F2), analyzing the levels of transcripts of the enzymes involved in the metabolism of T3 (Dio1), lipids (Fasn, Acc1), and glucose (G6pase, Pck1). Both processes were altered only in F2 males, affected by hypothyroidism and by a systemic hyperglycemia linked to the activation of gluconeogenesis in mice exposed to 1 and 10 mg/kg/die CPF. Interestingly, we observed an increase in active FOXO1 protein due to a decrease in AKT phosphorylation, despite insulin signaling activation. Experiments in vitro revealed that chronic exposure to CPF affected glucose metabolism via the direct modulation of FOXO1 activity and T3 levels in hepatic cells. In conclusion, we described different sex and intergenerational effects of CPF exposure on the hepatic homeostasis of THs, their signaling, and, finally, glucose metabolism. The data points to FOXO1-T3-glucose signaling as a target of CPF in liver.

Endocrine Disruptor Compounds in Environment: Focus on Women’s Reproductive Health and Endometriosis

Endometriosis is an estrogen-dependent gynecologic illness that has long-term effects on a woman’s fertility, physical health, and overall quality of life. Growing evidence suggests that endocrine-disrupting chemicals (EDCs) may be etiologically involved in the development and severity of the disease. We consider the available human evidence on EDCs and endometriosis, limiting ourselves to studies that have individually assessed chemical amounts in women. Dioxins, BPA, Phthalates, and other endocrine disruptors, like DDT, are among the evidence indicating an environmental etiology for endometriosis. Collectively, this review describes how environmental toxins are linked to lower fertility in women, as well as a number of reproductive diseases, focusing on the pathology of endometriosis and its treatments. Importantly, this review can be used to investigate techniques for preventing the negative effects of EDC exposure.

How safe is our food we eat? An electrochemical lab-on-kitchen approach towards combinatorial testing for pesticides and GMOs; A case study with edamame

In our daily life, as consumers we are constantly made aware of the impact of pesticides and other modifications to food products derived from genetically modified organisms (GMO's) that have an impact on human health. In our connected world, there is an immense interest for on-demand information about food quality prior to consumption. The gold standard method to detect pesticides or GMOs residues in food is complex and is not amenable to rapid consumer use. In this study, we demonstrate the feasibility of an electrochemical portable sensing approach for the simultaneous direct detection of spiked pesticides chlorpyrifos (Chlp) and GMOs protein Cry1Ab in real edamame soy matrix. The immunoassay based two-plex sensing platform was fabricated using respective antibody's Chlp on one side and Cry1Ab on other side. A simple lab-on-kitchen level preparation of matrix has been demonstrated and sensor response was tested using non-faradaic electrochemical impedance spectroscopy (EIS), which showed a linear response in Cry1Ab/Chlp concentrations from 0.3 ng/mL to 243 ng/mL with limit of detection 0.3 ng /mL for both the target antigens (Cry1Ab and Chlp) respectively. The spiked and recovery test results fall within ± 20% error in real sample matrix which demonstrates the performance of the our platform with maximum residue limit (MRL) for the given targets. Such electrochemical portable multi-analyte direct sensing tool with simple matrix processing protocol can be a future commercial field-testing tool for use at everyday consumer level.

The use of a simple model for the regulatory environmental risk assessment of pesticides in Ethiopia

Pesticide registration in developing countries like Ethiopia is often not supported by substantiated risk assessment procedures. In this study, we evaluated the PRIMET (Pesticide Risks in the Tropics for Man, Environment and Trade) Registration_Ethiopia_1.1 model which is a tool developed to assess the risks to non-target protection goals. All the 103 registered active ingredients (a.i.) in Ethiopia, except those used for flower and storage pest control purposes, were evaluated on their environmental risks. Data on physico-chemical characteristics, toxicity and pesticide use patterns were mined from either the information given in the dossier or public databases. Together with scenarios specifically developed for Ethiopia, these data were used to perform a risk assessment for the aquatic and terrestrial environment as well as for vertebrates including humans via contaminated drinking water exposure. Results indicated that 11 and 16% of the a.i.s are indicated to pose high acute risk and 7.3 and 11% high chronic risks for fish and aquatic invertebrates, respectively. Similarly, 5.5 and 8.7% high acute risks and 6.8 and 3.9% high chronic risks were observed for the soil ecosystem and birds, respectively. 23% of the evaluated active ingredients were indicated to be highly risky to bees when beehives are present inside the sprayed crop while 7.8% of them are highly risky when beehives are present outside the field of the sprayed crop. The fungicide metalaxyl, the herbicides acetochlor, alachlor, mecoprop and tembotrion, and the insecticides carbaryl, chlorpyrifos, diazinon and methidathion were predicted to pose high acute or chronic risks to humans or other vertebrates if surface water is used as a source of drinking water. Future studies should give emphasis on how the risk assessment results of this study can be implemented to aid the registration process.

Electrochemical biosensor based on cellulose nanofibers/graphene oxide and acetylcholinesterase for the detection of chlorpyrifos pesticide in water and fruit juice†

In this work, cellulose nanofibers and graphene oxide are used to fabricate a simple and reliable electrochemical biosensor, based on acetylcholinesterase (AChE) for the detection of highly dangerous organophosphates (OPs), utilizing chlorpyrifos as a representative sample. AChE is an enzyme that is essential for neurotransmission and catalyzes the conversion of acetylcholine (ATCh) into thiocholine and acetic acid. The pesticide used in this work, chlorpyrifos, inhibits the catalytic activity of AChE on ATCh, and this inhibition can be measured using square wave voltammetry (SWV). Utilizing a process of surface modification, layers of cellulose nanofibers, graphene oxide, a chitosan-graphene oxide composite, and acetylcholinesterase (AChE/CS-GO/GO/CNFs) were immobilized on a screen-printed carbon electrode (SPCE). The modified SPCE working electrode was characterized using scanning electron microscopy and graphene oxide trapped in the cellulose nanofibers was found to increase the sensitivity of the biosensor. The modified biosensor demonstrated good performance for detection of chlorpyrifos over a linear range of 25–1000 nM under optimum conditions, and the limits of detection and quantification were 2.2 nM and 73 nM, respectively. Our sophisticated technique might offer a more precise, straightforward, quick, and environmentally friendly way to assess chlorpyrifos contamination in water and juice samples.

Cellulose nanofibers and graphene oxide are used to fabricate an electrochemical biosensor based on acetylcholinesterase for detecting organophosphates. This biosensor is simple and reliable, and it utilizes chlorpyrifos as a representative sample of highly dangerous OPs.

Metabolome-wide association study of the relationship between chlorpyrifos exposure and first trimester serum metabolite levels in pregnant Thai farmworkers

INTRODUCTION

Organophosphate (OP) insecticides, including chlorpyrifos, have been linked with numerous harmful health effects on maternal and child health. Limited data are available on the biological mechanisms and endogenous pathways underlying the toxicity of chlorpyrifos exposures on pregnancy and birth outcomes. In this study, we measured a urinary chlorpyrifos metabolite and used high-resolution metabolomics (HRM) to identify biological perturbations associated with chlorpyrifos exposure among pregnant women in Thailand, who are disparately exposed to high levels of OP insecticides.

METHODS

This study included 50 participants from the Study of Asian Women and their Offspring's Development and Environmental Exposures (SAWASDEE). We used liquid chromatography-high resolution mass spectrometry to conduct metabolic profiling on first trimester serum samples collected from participants to evaluate metabolic perturbations in relation to chlorpyrifos exposures. We measured 3,5,6-trichloro-2-pyridinol (TCPy), a specific metabolite of chlorpyrifos and chlorpyrifos-methyl, in first trimester urine samples to assess the levels of exposures. Following an untargeted metabolome-wide association study workflow, we used generalized linear models, pathway enrichment analyses, and chemical annotation to identify significant metabolites and pathways associated with urinary TCPy levels.

RESULTS

In the 50 SAWASDEE participants, the median urinary TCPy level was 4.36 μg TCPy/g creatinine. In total, 691 unique metabolic features were found significantly associated with TCPy levels (p < 0.05) after controlling for confounding factors. Pathway analysis of metabolic features associated with TCPy indicated perturbations in 24 metabolic pathways, most closely linked to the production of reactive oxygen species and cellular damage. These pathways include tryptophan metabolism, fatty acid oxidation and peroxisome metabolism, cytochromes P450 metabolism, glutathione metabolism, and vitamin B3 metabolism. We confirmed the chemical identities of 25 metabolites associated with TCPy levels, including glutathione, cystine, arachidic acid, itaconate, and nicotinamide adenine dinucleotide.

DISCUSSION

The metabolic perturbations associated with TCPy levels were related to oxidative stress, cellular damage and repair, and systemic inflammation, which could ultimately contribute to health outcomes, including neurodevelopmental deficits in the child. These findings support the future development of sensitive biomarkers to investigate the metabolic underpinnings related to pesticide exposure during pregnancy and to understand its link to adverse outcomes in children.

Binding and Detoxification of Insecticides by Potentially Probiotic Lactic Acid Bacteria Isolated from Honeybee (Apis mellifera L.) Environment-An In Vitro Study

Lactic acid bacteria (LAB) naturally inhabiting the digestive tract of honeybees are known for their ability to detoxify xenobiotics. The effect of chlorpyrifos, coumaphos, and imidacloprid on the growth of LAB strains was tested. All strains showed high resistance to these insecticides. Subsequently, the insecticide binding ability of LAB was investigated. Coumaphos and chlorpyrifos were bound to the greatest extent (up to approx. 64%), and imidacloprid to a much weaker extent (up to approx. 36%). The insecticides were detected in extra- and intracellular extracts of the bacterial cell wall. The ability of selected LAB to reduce the cyto- and genotoxicity of insecticides was tested on two normal (ovarian insect Sf-9 and rat intestinal IEC-6) cell lines and one cancer (human intestinal Caco-2) cell line. All strains exhibited various levels of reduction in the cyto- and genotoxicity of tested insecticides. It seems that coumaphos was detoxified most potently. The detoxification abilities depended on the insecticide, LAB strain, and cell line. The detoxification of insecticides in the organisms of honeybees may reduce the likelihood of the penetration of these toxins into honeybee products consumed by humans and may contribute to the improvement of the condition in apiaries and honeybee health.