Carbamate Insecticides Research Articles

Mixture toxicity assessment of selected insecticides to silver perch fingerling, Bidyanus bidyanus

The organophosphorus (OP) and carbamate (CB) insecticides are responsible for inhibition of the Acetylcholinesterase (AChE) enzyme. The AChE activity, therefore, has been demonstrated to be a potent biomarker for these insecticides in terrestrial and aquatic environments. The objective of this study was to investigate the response of AChE in the brain of four-week old fingerlings of silver perch, Bidyanus bidyanus exposed to OP and CB insecticides. The fish fingeling were exposed to three OPs and one CB insecticide as individual and their binary mixtures for 48 h. The OP insecticides with oxon (PO) as well as thion (PS) group gets oxidized to oxon analogs in biological systems. The 50% AChE inhibition (48 h EC50) in fingerling exposed to chlorpyrifos (CPF) and triazophos (TRZ) was evident at 2.3 and 6.7 µg/L, respectively. The toxicological interaction of three OPs and one CB insecticide was evaluated using the toxic unit method. A strong synergism was observed for binary combination of CPF with profenofos (PRF), and CPF with TAZ. In contrast, the mixture of TAZ with PRF and carbofuran (CBF) with CPF and PRF showed antagonistic behavior. Although OP and CB insecticides can break down rapidly in the environment, this study suggests that non-target aquatic biota may be exposed to mixtures of ChE-inhibiting insecticides for a period of several months, in agricultural regions where insecticides are applied for extended periods of the year. And at environmentally relevant concentrations such mixtures may lead to deleterious effects in non-target organisms.

Study of the binding interaction between bovine serum albumin and carbofuran insecticide: Multispectroscopic and molecular docking techniques

Carbofuran is an agricultural use nematicide, acaricide, and broad-spectrum systematic anticholinesterase carbamate insecticide. Carbofuran accumulates in foodstuffs and has many hazardous effects on animal and human health through ingestion and respiration. People with a cardiovascular condition, asthma, diabetes, mechanical obstruction of the gastrointestinal or urinary tract are more prone to these effects. Therefore, there is a need to develop a responsive and economical approach to understand the molecular interaction between carbofuran and serum protein. In this paper, carbofuran is examined for interaction with bovine serum albumin across several spectroscopic methods. The fluorescence quenching study of bovine serum albumin withCarbofuran revealed the static nature of quenching. The Stern-Volmer constant (Ksv) for Carbofuran interaction with bovine serum albumin was found to be 2.02 × 104 dm3 mol−1 at 298 K. Circular dichroism studies showed minor changes in the secondary structure of albumin on interaction with bovine serum albumin. The binding of carbofuran at Site I of bovine serum albumin was confirmed by competitive molecular docking studies. The present work may provide new insights into the mechanism of carbofuran toxicity and its health consequences.

The Hepatoprotective Role of Balanites aegyptiaca Extract and its Nano-Formulation Against Methomyl-Induced Toxicity and Oxidative Stress in Mice via Overexpression of Nrf2

IntroductionMethomyl (MET) is a monomethyl carbamate insecticide that is widely used around the world. MET is highly toxic to humans via oral exposure and mainly affects the liver tissue. It actually induces toxicity through overproduction of Reactive Oxygen Species (ROS) leading to oxidative stress with subsequent destruction of lipids, proteins, and nucleic acids.Materials and MethodsVarious plant extracts have been primarily screened for their antioxidant activities by measuring the free radical scavenging ability. Later, the plant extract with the highest antioxidant efficacy has been further formulated into a nanosuspension and the antioxidative effect has also been investigated against MET. Additionally, liver, kidney, and heart function biomarkers, liver tissue oxidative stress parameters, and total antioxidant capacity were assessed. Moreover, RT-PCR was applied to measure the Nrf2 expression.ResultsThe antioxidant screening data showed that balanites extract (BLT, Balanites aegyptiaca) had the most potent antioxidant activity. Besides, BLT showed dose-dependent improvement in liver, heart, and kidney functions in experimental mice treated with MET. The antioxidant biomarkers in liver tissue and total antioxidant capacity were elevated as compared to the MET-treated group. Furthermore, BLT significantly ameliorated MET-induced toxicity via the induction of Nrf2 and MET hepatic clearance. This study suggests the potential use of BLT extract as a natural antioxidant for the safe management of MET-induced hepatotoxicity and oxidative stress.ConclusionsBased on the presented data in this study, it can be concluded that BLT or BLT-NS can be used as a safe drug for methomyl toxicity.

The endocrine-disrupting potential of a generic carbamate insecticide methomyl, as explored in a 90-day study in vivo

The endocrine-disrupting potential of a generic carbamate insecticide methomyl, as explored in a 90-day study in vivo

Heterologous expression and exploration of the enzymatic properties of the carbaryl hydrolase CarH from a newly isolated carbaryl-degrading strain

Carbaryl is the representative of carbamate insecticide. As an acetylcholinesterase inhibitor, it poses potential threat to humans and other non-target organisms. Agrobacterium sp. XWY-2, which could grow with carbaryl as the sole carbon source, was isolated and characterized. The carH gene, encoding a carbaryl hydrolase, was cloned from strain XWY-2 and expressed in Escherichia coli BL21 (DE3). CarH was able to hydrolyze carbamate pesticides including carbaryl, carbofuran, isoprocarb, propoxur and fenobucarb efficiently, while it hydrolyzed oxamyl and aldicarb poorly. The optimal pH of CarH was 8.0 and the optimal temperature was 30 ℃. The apparent Km and kcat values of CarH for carbaryl were 38.01 ± 2.81 μM and 0.33 ± 0.01 s−1, respectively. The point mutation experiment demonstrated that His341, His343, His346, His416 and D437 are the key sites for CarH to hydrolyze carbaryl.

Characterization of Acetylcholinesterase from Various Sources: A Mini Re

In this review, various aspects of acetylcholinesterase (AChE) are reviewed. Acetylcholinesterase (AChE, EC3.1.1.7) is an important neurotransmitter because it hydrolyses the neurotransmitter acetylcholine (ACh), it is also the target site of organophosphorus and carbamate insecticides. The discovery of the first neurotransmitter ACh was soon followed by the discovery of its hydrolysing enzyme, AChE. The role of AChE in terminating AChE-mediated neurotransmission made it the focus of intense research for much of the past century. The role of butyrylcholinesterase (BChE) is not known but it is assumed to participate in the growth and development and to scavenge the cholinergic toxins, it is also reported to have an auxiliary role in synaptic transmission. Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) are the major groups of cholinesterase differentiated by their substrate preferences. Substrate binding specificity and catalytic efficiency are tangled in enzyme catalysis. The fact that an enzyme may exist in more than one molecular form has been accepted for a number of years.

Occupational insecticide exposure and risk of non-Hodgkin lymphoma: A pooled case-control study from the InterLymph Consortium.

Evidence for the human health effects of pesticides is needed to inform risk assessment. We studied the relationship between occupational insecticide use and risk of non-Hodgkin lymphoma (NHL) by pooling data from nine case-control studies participating in the InterLymph Consortium, including 7909 cases and 8644 controls from North America, the European Union and Australia. Insecticide use was coded using self-report or expert assessment, for insecticide groups (eg, organophosphates, pyrethroids) and active ingredients (eg, malathion, permethrin). Associations with insecticides were estimated using logistic regression to produce odds ratios (ORs) and 95% confidence intervals (CI) for all NHL and NHL subtypes, with adjustment for study site, demographic factors and use of other pesticides. Occupational insecticide use, overall, was not associated with risk of NHL. Use of organophosphate insecticides was associated with increased risk of all NHL and the subtype follicular lymphoma, and an association was found with diazinon, in particular (ever use: OR=2.05, 95%CI: 1.24-3.37). The carbamate insecticide, carbaryl, was associated with risk of all NHL, and the strongest associations were found with T-cell NHL for ever-use (OR=2.44, 95%CI: 1.13-5.28) and longer duration (>8 years vs never: OR=2.90, 95%CI: 1.02-8.25). There was no association of NHL with other broad groups of insecticides, including organochlorines and pyrethroids, and some inverse associations were estimated in relation to historical DDT use. Our findings contribute to the totality of evidence available to help inform risk decisions by public health and regulatory agencies of importance given continued, widespread use of organophosphate and carbamate insecticides.

Bioefficacy of bendiocarb WP80 in vector-borne and zoonotic diseases areas in borderline of Iran and Pakistan.

Malaria and leishmaniasis are the public health problems in southern Iran. The main activity of vector control is indoor residual spraying using pyrethroids, using different insecticides as larviciding and impregnated bednets. The aim of study was to evaluate the biological assays of bendiocarb wettable powder (WP) at different surfaces of wall. The residual effect of bendiocarb WP80 at 400 milligram/meter square (mg/m2) was evaluated on various local surfaces of rooms such as mud and plaster as well as thatch roofs and wooden. World Health Organization standard cones using contact bioassays were carried out using laboratory reared sugar-fed, 48-72 h old females of Anopheles stephensi. Contact bioassays were carried out on sprayed surfaces for 150 days. Contact bioassay on surfaces treated with bendiocarb WP80 at different surfaces was estimated about 2 months. Fumigant tests of bendiocarb WP80 at 400 mg/m2 revealed 50-93.83% mortality with 1 month persistency. The results showed that carbamate insecticide could be used as rotation with pyrethroids for malaria vector control. Monitoring and evaluation of environmental toxicology of pesticides is important for decision making for choosing appropriate pesticides for disease vector control.

Electrochemically-driven regeneration of iron (II) enhances Fenton abatement of pesticide cartap

Cartap is a carbamate insecticide intended to protect crops such as rice, tea, and sugarcane. Cartap in the environment presents a serious threat to non-target organisms through direct exposure or via biomagnification. Electro-assisted Fenton technology taps the potential of Fenton reagents to degrade cartap. Electrochemical reduction of iron accelerates catalyst regeneration. Cartap degradation was first investigated by varying reaction pH, as well as the initial H2O2 and Fe2+ dosage, followed by optimization studies using central composite design. Parametric results indicate the highest cartap removal of 98.10% was achieved at 1.6 pH, 3.0 mM Fe2+, and 40 mM H2O2 at I = 1.0 A and t = 30 min. These results notoriously surpass conventional Fenton that only achieved 53.8% cartap removal under similar conditions. The hybridization of Fenton process through electrochemical regeneration enhances removal and increases degradation kinetic up to a pseudo-first-order rate constant value of 21.30 × 10–4 s−1. Effects of coexisting inorganic salts PO43–, NO3–, and Cl– at 1 mM and 10 mM concentrations were investigated. These results demonstrate that Fenton electrification as process intensification alternative can enhance the performance and competitiveness of conventional Fenton by ensuring higher availability of iron catalyst while minimizing sludge production.

Organophosphate and carbamate insecticide exposure is related to lung function change among smallholder farmers: a prospective study

Introduction and aimExposure to some insecticides may cause airway obstruction, but existing evidence is limited by cross-sectional designs and inadequate confounder control. We investigated the relation between organophosphate and carbamate...

Monitoring and Mapping of Insecticide Resistance in Medically Important Mosquitoes (Diptera: Culicidae) in Iran (2000-2020): A Review.

Background:Mosquitos due to their role in the transmission of different pathogens to humans are considered as an important group in the phylum Arthropoda. According to the WHO and FAO guideline different groups of insecticide applied for controlling pests in both the agricultural and public health sectors.Methods:All the data published about resistant status of the mosquitoes Anopheles, Culex, Aedes and Culiseta species were searched on PubMed, Elsevier, Web of Science, Magiran and google scholar. The objectives of this study was to review the trend of resistance to insecticides during 2000–2020 in medically important mosquitoes in Iran. The criteria for resistant are followed according to WHO guideline.Results:The Results showed that there are widespread, multiple resistances in the country to different organochlorine, organophosphates, carbamate and pyrethroids insecticides in the mosquitoes.Conclusion:The effect of pesticide residues on the environment could be a cause for selection pressure on mosquitos and lead to insecticides resistance to them. Insecticides resistance is main challenge of the vector control program. Also result will provide a guideline for control of the mosquito-borne diseases in the country as well as the world.

Residential exposure to carbamate, organophosphate, and pyrethroid insecticides in house dust and risk of childhood acute lymphoblastic leukemia

BackgroundSelf-reported residential use of pesticides has consistently been associated with increased risk of childhood leukemia. However, these studies were limited in their ability to identify specific insecticide active ingredients that were associated with risk. ObjectiveWe used household carpet dust measurements of 20 insecticides (two carbamate, 10 organophosphate, two organochlorine, and six pyrethroid) as indicators of exposure and evaluated associations with the risk of childhood acute lymphoblastic leukemia (ALL). MethodsWe conducted a population-based case-control study of 252 ALL cases diagnosed from 1999 to 2007 and 306 birth certificate controls from 35 counties in Central and Northern California. Carpet dust was collected at a second interview (2001–2007) for cases who had not moved since diagnosis (comparable reference date for controls) using a specialized vacuum cleaner in the room where the child spent most of their time or from the household vacuum. Insecticides were categorized as detected (yes/no), or as tertiles or quartiles of their distributions among controls. We calculated odds ratios (OR) and 95% confidence intervals (CI) using unconditional logistic regression adjusting for demographic characteristics, interview year, and season of dust collection. ResultsPermethrin, chlorpyrifos, diazinon, and carbaryl were the most frequently detected insecticide active ingredients. When we compared the highest quartile to the lowest or to non-detections, there was no association with ALL for permethrin (OR Q4 vs. Q1 = 0.81; 95% CI 0.50–1.31), carbaryl (OR Q4 vs. non-detects = 0.61, 95% CI 0.34–1.08) or chlorpyrifos (OR Q4 vs. Q1 = 0.60; 95% CI 0.36–1.00). The highest quartile of diazinon concentration was inversely associated with risk in the single pesticide model but without a monotonic exposure-response (p-trend = 0.14). After adjusting for other common insecticides, the OR was not significant (OR Q4 vs. Q1 = 0.58; 95% CI 0.33–1.05). None of the other insecticides were associated with risk. ConclusionOur results should be interpreted within the limitations of the case-control study design including the use of a single post-diagnosis dust sample and restriction to residentially stable participants, which may have resulted in selection bias. Although difficult to implement, additional studies with assessment of exposure to insecticide active and non-active ingredients are necessary to elucidate the role of these common exposures in childhood leukemia risk.

Association between pesticide exposure and obesity: A cross-sectional study of 20,295 farmers in Thailand

Background: Obesity isaseriousconditionbecause it is associated with other chronic diseaseswhichaffect the quality of life. In addition to diet and exercise, recent research has foundthatpesticide exposure might be another important risk factor. Methods: The objective of this large cross-sectional study was to determine the association between pesticide exposure and obesityamong farmers in Nakhon Sawan andPhitsanulokprovince, Thailand. Data on pesticide use and obesity prevalence from 20,295 farmers aged 20 yearsandolder was collected usingan in-person interviewquestionnaire. The associationwas analysed using multivariable logistic regression, adjusted for its potential confounding factors. Results:Obesity was found to be associated with pesticide use in the past. The risk of obesity was significantly predicted by types of pesticides, including insecticides(OR=2.27, 95% CI 1.09-4.74), herbicides (OR=4.72, 95% CI 1.16-19.29), fungicides (OR=2.17, 95% CI 1.37-3.44), rodenticides (OR=2.52, 95% CI 1.59-3.99),and molluscicides(OR=3.37, 95% CI 2.13-5.31).Among 35 surveyed individual pesticides, 24 were significantly associated with higher obesity prevalence (OR = 1.75, 95% CI 1.00-3.06 to OR = 8.37, 95% CI 3.97-17.64),including herbicide butachlor, 17 insecticides (threecarbamate insecticides,fiveorganochlorine insecticides, andnineorganophosphate insecticides), andsixfungicides. Conclusion:This study found obesity in farmers in Nakhon Sawan andPhitsanulokprovince,Thailand,to be associated withthelong-termuse of several types of pesticides. The issue should receive more public attention, and pesticide use should be strictly controlled.

Multiclass Pesticide Residue Analysis in Fruit and Vegetable Samples by Combining Acetone-Based Salting-Out Assisted Extraction with Dispersive Liquid-Liquid Microextraction

Isolation and enrichment of multiclass pesticides’ residue, namely, fungicides (benalaxyl), herbicides (atrazine), carbamate insecticides (carbofuran), organophosphate insecticides (chlorpyrifos), organochlorine insecticides (4,4′-DDT), and pyrethroid insecticides (bifenthrin), were made by combining acetone-based salting-out assisted extraction with the dispersive liquid-liquid microextraction (SADLLME) method, followed by high-performance liquid chromatography-diode array detection (HPLC-DAD). The effect of the type and volume of the extraction solvent in the pretreatment step, the volume of the disperser solvent (acetone extract), the type and volume of the extraction solvent, pH, and salt addition in the DLLME procedure was studied. Good coefficient of determination (R2 ≥ 0.9964) was obtained for all the target analytes. The limits of detection and quantification limits were between 2.1 and 4.5 and 5.7 and 12.9 µg/kg, respectively, with adequate enrichment factors ranging from 37.6 to 191. The recoveries of spiked blank tomato ranged from 86.8 to 109.5%. The limit of quantification of the proposed method was lower than the maximum residue limits set by the European Union. The repeatability and reproducibility of precisions ranged between 2.9 and 8.0 and 4.9 and 9.5%, respectively. The optimized and validated method was applied to quantify pesticides in tomato, pear, apple, and melon obtained from different markets. However, all target compounds studied in this work were not detected in any real samples applied. Overall, the work results revealed that the proposed method is useful for the sample extraction and preconcentration of the target analytes from fruits and vegetables.

Ambient moisture causes methomyl residues on corn plants to rapidly lose toxicity to the pest slug, Arion subfuscus, Müller (Gastropoda, Stylommatophora)

The carbamate insecticide methomyl is sometimes used to control slugs in field corn and soybean by foliar applications, but control outcomes in research trials and commercial operations have been mixed. In this study, laboratory bioassays were conducted on dusky slug, Arion subfuscus Müller, a common pest of corn and soybean in the Mid-Atlantic United States, to evaluate residual toxicity of Lannate LV (methomyl) at low and high concentrations corresponding to label recommended field rates, and if toxicity may be affected by ambient moisture or repellency to treated plants. Without wetting events, methomyl residues on corn plants caused 90–100% mortality of A. subfuscus for two days and 70–90% mortality for six days. When corn plants were briefly misted with ca. 0.3 cm of water 6 h after methomyl application, mortality was 36% 12 h after treatment, and 0 to 5% 24 h after treatment for both low and high rates. Repellency of A. subfuscus to corn plants treated with the high rate of methomyl was narrowly significant (P = 0.04) and low rate was not significant. These results suggest that high ambient moisture needed to elicit slug activity in the field also abates toxicity of methomyl residues, explaining why field control is usually poor despite high mortality in the lab.

Oxidative stress induced by methomyl exposure reduces the quality of early embryo development in mice.

Methomyl is a widely used carbamate insecticide and environmental oestrogen that has adverse effects on the reproductive system. However, there have been no reports on the effect of methomyl on early embryos in mammals. In this study, we explored the effect of methomyl exposure on the quality of early embryonic development in mice and the possible mechanisms. During in vitro culture, different concentrations of methomyl (10, 20, 30 and 35 μM) were added to mouse zygote medium. The results showed that methomyl had an adverse effect on early embryonic development. Compared with the control group, the addition of 30 μM methomyl significantly reduced the rate of early embryo blastocyst formation. Methomyl exposure can increase oxidative stress and impair mitochondrial function, which may be the cause of blastocyst formation. In addition, we found that methomyl exposure promoted apoptosis and autophagy in mouse blastocysts. The toxic effect of methomyl on early embryos may be the result of oxidative stress induction. Taken together, our results indicate that methomyl can cause embryonic development defects in mice, thereby reducing the quality of early embryo development.

Florida says no to aldicarb on citrus

Citrus growers in Florida cannot use the pesticide aldicarb to combat citrus greening caused by the Asian citrus psyllid, the state announced April 21 . The decision reverses a last-minute approval by the Trump administration allowing use of the chemical on citrus crops in Florida under federal law . The Florida Department of Agriculture and Consumer Services denied the request from pesticide maker AgLogic Chemical to register aldicarb for use on citrus in the state, claiming that the chemical poses unacceptable health risks to humans, wildlife, and the environment. Aldicarb, an older carbamate insecticide, “is one of the world’s most toxic pesticides and is banned in more than 100 countries,” Nikki Fried, Florida’s agriculture commissioner, says in a statement. The US Environmental Protection Agency declared in 2010 that aldicarb may pose health risks to infants and young children. At the time, Bayer Crop Science agreed to immediately stop selling it

Ovicidal, Larvicidal and Biochemical Effects of Thyme, Thymus vulgaris, ON the Cotton Leafworm, Spodoptera littoralis (Boisd.)

Ovicidal,larvicidal and biochemical effects of Thyme oil,Thymus vulgaris,and the carbamate insecticide,Methomyl,on the cotton leafworm, Spodoptera littoralis (boisd.) (Lepidoptera: Noctuidae)were studied.The calculated percentages of reduction in egg hatching were 32.5, and 57.1% for thyme oil tested at concentrations of 2 and 4% and 21.3, and 28.2% for Methomyl tested at concentrations of 2 and 4ppm, respectively.The calculated percentages of reduction were 100% for thyme oil and Methomyl tested at concentrations of 12% and 20ppm, respectively.Larval feeding assay showed that the calculated LC50 values for thyme oil were 0.701, 0.324 and 0.108% after 24, 48 and 72hrs, respectively.The calculated LC50 values for methomyl were 1.60, 0.918 and 0.51ppm after 24, 48 and 72hrs,respectively.Topical assay showed that the calculated LC50 values were 3.601, 3.601, and 2.089% after 24, 48, and 72hrs, respectively.Among methomyl, the calculated LC50 values were 2.12, 1.28 and 0.75ppm after 24, 48 and 72hrs, respectively. The in vitro inhibitory activity of Thyme oil and Methomyl on acetylcholinesterase (AChE) were also tested in larval head and midgut of S. littoralis in this study.Concentration of 6% of Thyme oil caused 68.6 and 68.7% inhibition of AChE in heads and midgut of the 4th larval instar of S. littoralis, respectively. While concentration of 20 ppm of methomyl caused 81.8 and 80.4% inhibition of AChE in heads and midgut of the 4th larval instar of S. littoralis, respectively. I50 values for larval midgut AChE was about 1.3 and 1.52 folds more resistant to inhibition by thyme oil and methomyl,respectively,than those of larval head AChE.

Insecticide susceptibility of Phlebotomus argentipes sandflies, vectors of visceral leishmaniasis in India.

Indoor residual spraying (IRS) with insecticides is the main vector control intervention for the elimination of visceral leishmaniasis in India. After a change in IRS policy in 2015 due to widespread resistance of Phlebotomus argentipes to DDT, IRS with DDT was replaced with alpha-cypermethrin IRS in 2016. The objective of the present study was to evaluate the susceptibility of P.argentipes to DDT and its alternatives, namely malathion and pirimiphos-methyl (organophosphates); alpha-cypermethrin, deltamethrin, lambda-cyhalothrin and permethrin (pyrethroids), and bendiocarb and propoxur (carbamates), in support of visceral leishmaniasis elimination in India. Phlebotomus argentipes sandflies were collected from the visceral-leishmaniasis endemic states of Bihar, Jharkhand and West Bengal. In the WHO tube tests, the phenotypic susceptibility of F1, 2-day old, non-blood fed females were determined against filter papers impregnated with DDT 4%, malathion 5%, pirimiphos-methyl 0.25%, alpha-cypermethrin 0.05%, deltamethrin 0.05%, lambda-cyhalothrin 0.05%, permethrin 0.75%, bendiocarb 0.1% and propoxur 0.1%, which were sourced from Universiti Sains Malaysia. The knockdown of sandflies after 1-h exposure and mortality at 24h after the 1-h exposure period were scored. Mean mortality of P.argentipes 24h after exposure in tube tests was 22.6% for DDT and ≥ 98% for other insecticide-impregnated papers tested. Phlebotomus argentipes continues to be highly resistant to DDT with no reversal of resistance after DDT's withdrawal from IRS. P.argentipes was fully susceptible to pyrethroid, organophosphate and carbamate insecticides tested. Regular monitoring is warranted for insecticide resistance management in sandfly vectors.

Urinary metabolites of non-persistent pesticides and serum hormones in Spanish adolescent males

ObjectiveTo assess the relationship of urinary concentrations of ethylenethiourea (ETU), the main degradation product of ethylene bis-dithiocarbamate fungicides, 3-phenoxybenzoic acid (3-PBA), a common metabolite of many pyrethroids, and 1-naphthol (1N), a metabolite of the carbamate insecticide carbaryl, with hormone concentrations in adolescent males; and to examine interactions between pesticide metabolites and polymorphisms in xenobiotic metabolizing enzymes, including CYP2C19 and CYP2D6, in relation to hormone concentrations. MethodsA cross-sectional study was conducted in 134 males from the Spanish Environment and Childhood (INMA)-Granada cohort. Urine and serum samples were collected from participants during the same clinical visit at the age of 15–17 years. First morning urine void was analyzed for concentrations of ETU, 3-PBA, and 1N. Serum was analyzed for concentrations of reproductive hormones (testosterone, 17β-estradiol [E2], dehydroepiandrosterone sulfate [DHEAS], sex hormone binding globulin [SHBG], luteinizing hormone [LH], follicle stimulating hormone [FSH], anti-Müllerian hormone [AMH], and prolactin), thyroid hormones (free thyroxine [FT4], total triiodothyronine [TT3], and thyroid stimulating hormone [TSH]), insulin growth factor 1 (IGF-1), adrenocorticotropic hormone (ACTH), and cortisol. CYP2C19 G681A and CYP2D6 G1846A polymorphisms were determined in blood from 117 participants. Multiple linear regression, interaction terms, and stratified analyses were performed. ResultsUrinary ETU was detected in 74.6% of participants, 1N in 38.1%, and 3-PBA in 19.4%. Positive associations between detectable 3-PBA and TT3 and between detectable 1N and DHEAS were found, and marginally-significant associations of 1N with reduced E2 and FSH were observed. Poor CYP2C19 and CYP2D6 metabolizers (GA and AA genotype carriers) showed a greater increase in DHEAS for detected versus undetected 1N compared with GG genotype carriers. Poor CYP2D6 metabolizers (1846 GA and AA genotypes) evidenced increased cortisol for detected versus undetected ETU. ConclusionsThe associations observed between urinary pesticide metabolites and altered thyroid and reproductive hormones are novel and should be verified in studies with larger sample size. Further research on gene-environment interactions is warranted to establish individual susceptibility to pesticides and the risk of adverse health effects.