Exposure to neonicotinoids and serum testosterone in men, women, and children

Disinfection byproducts in US drinking water and cancer mortality

Trihalomethanes, the main drinking water disinfection byproducts, may be carcinogenic and are regulated to amaximum total trihalomethanes (TTHM) of 80 µg/l in the US. We aimed to determine whether total and individual trihalomethanes in drinking water across the US are associated with higher cancer mortality in 6,260 adult participants to the National Health and Nutrition Examination Surveys from 1999 to 2008 followed for mortality until 2019 (median: 14.4 years). At baseline, the geometric mean (standard error) of TTHM in drinking water was 9.61 (0.85) µg/l. During follow-up, 873 deaths occurred, including 207 from cancer. In Cox proportional hazards regression adjusted for relevant covariates, drinking water TTHM (HR: 1.45, 95% CI: 1.16-1.82), chloroform (HR: 1.35, 95% CI: 1.12-1.64), and bromodichloromethane (HR: 1.30, 95% CI: 1.05-1.59) were associated with 30% to 45% higher cancer mortality. Therefore, drinking water trihalomethanes, especially chloroform and bromodichloromethane maybe risk factors for cancer mortality.

Exposure of pregnant women to neonicotinoids in Wenzhou City, East China: A biomonitoring study

BACKGROUND

China produces and consumes a large amount of neonicotinoids. A non-negligible exposure to neonicotinoids might occur for Chinese pregnant women, but relevant data remain limited.

OBJECTIVE

To investigate the exposure to neonicotinoids by urinary biomonitoring in pregnant women from Wenzhou City, East China.

METHODS

We selected 432 pregnant women in Wenzhou City in 2022. A total of eight parent neonicotinoids and four metabolites were determined in single spot urine by liquid chromatography coupled to mass spectrometry. Basic characteristics, physical activity, pre-pregnant body mass index, and intake of drinking water and food were investigated by the questionnaire. Health risk was assessed by hazard quotient (HQ) and hazard index (HI) based on human safety thresholds derived from different health endpoints.

RESULTS

Neonicotinoids and their metabolites in urine had a detection frequency between 0 % and 80.1 %. At least one neonicotinoid or metabolite was detected in 93.5 % of urine samples. Except for clothianidin (51.2 %) and N-desmethyl-acetamiprid (80.1 %), the detection frequencies of other neonicotinoids and metabolites ranged from 0 % to 43.8 %. The summed concentrations of all neonicotinoids and their metabolites ranged from < LOD to 222.83 μg/g creatinine with the median concentration of 2.58 μg/g creatinine. Maternal age, educational level, occupation, household income, screen time, and pre-pregnant body mass index were associated with detection frequencies or concentrations of neonicotinoids and their metabolites. Pregnant women with higher consumption frequencies of wheat, fresh vegetable, shellfish, fresh milk, and powdered milk had higher detection frequencies of neonicotinoids and their metabolites. Both HQ and HI were less than one.

CONCLUSIONS

Overall, pregnant women in Wenzhou City showed a notable frequency of exposure to at least one neonicotinoid, although the exposure frequency for each specific neonicotinoid was generally low. Several food items derived from plants and animals were potential exposure sources. A low health risk was found based on current safety thresholds.

Sex and adrenal hormones in association with insecticide biomarkers among adolescents living in ecuadorian agricultural communities

BACKGROUND

Organophosphate, pyrethroid, and neonicotinoid insecticides have resulted in adrenal and gonadal hormone disruption in animal and in vitro studies; limited epidemiologic evidence exists in humans. We assessed relationships of urinary insecticide metabolite concentrations with adrenal and gonadal hormones in adolescents living in Ecuadorean agricultural communities.

METHODS

In 2016, we examined 522 Ecuadorian adolescents (11-17y, 50.7% female, 22% Indigenous; ESPINA study). We measured urinary insecticide metabolites, blood acetylcholinesterase activity (AChE), and salivary testosterone, dehydroepiandrosterone (DHEA), 17β-estradiol, and cortisol. We used general linear models to assess linear (β = % hormone difference per 50% increase of metabolite concentration) and curvilinear relationships (β2 = hormone difference per unit increase in squared ln-metabolite) between ln-metabolite or AChE and ln-hormone concentrations, stratified by sex, adjusting for anthropometric, demographic, and awakening response variables. Bayesian Kernel Machine Regression was used to assess non-linear associations and interactions.

RESULTS

The organophosphate metabolite malathion dicarboxylic acid (MDA) had positive associations with testosterone (βboys = 5.88% [1.21%, 10.78%], βgirls = 4.10% [-0.02%, 8.39%]), and cortisol (βboys = 6.06 [-0.23%, 12.75%]. Para-nitrophenol (organophosphate) had negatively-trending curvilinear associations, with testosterone (β2boys = -0.17 (-0.33, -0.003), p = 0.04) and DHEA (β2boys = -0.49 (-0.80, -0.19), p = 0.001) in boys. The neonicotinoid summary score (βboys = 5.60% [0.14%, 11.36%]) and the neonicotinoid acetamiprid-N-desmethyl (βboys = 3.90% [1.28%, 6.58%]) were positively associated with 17β-estradiol, measured in boys only. No associations between the pyrethroid 3-phenoxybenzoic acid and hormones were observed. In girls, bivariate response associations identified interactions of MDA, Para-nitrophenol, and 3,5,6-trichloro-2-pyridinol (organophosphates) with testosterone and DHEA concentrations. In boys, we observed an interaction of MDA and Para-nitrophenol with DHEA. No associations were identified for AChE.

CONCLUSIONS

We observed evidence of endocrine disruption for specific organophosphate and neonicotinoid metabolite exposures in adolescents. Urinary organophosphate metabolites were associated with testosterone and DHEA concentrations, with stronger associations in boys than girls. Urinary neonicotinoids were positively associated with 17β-estradiol. Longitudinal repeat-measures analyses would be beneficial for causal inference.

Statement on the toxicological properties and maximum residue levels of acetamiprid and its metabolites

Acetamiprid is a pesticide active substance with insecticidal action whose approval was renewed by Commission Implementing Regulation (EU) 2018/113. In January 2022, the EFSA PPR Panel published a statement following a request from the European Commission to advise on human health or the environment based on new scientific evidence presented by France during the decision-making phase. In July 2022, by means of a further mandate received from the European Commission, EFSA was requested to provide advice if new information and any other scientific evidence that has become available since the assessment conducted for the renewal in 2018 warrant re-evaluation of (i) toxicological parameters used for the risk assessment of acetamiprid during the renewal process, including toxicological endpoints; (ii) the residue definition for acetamiprid in products of plant origin; and (iii) the safety of existing maximum residue levels (MRLs). Meanwhile, the applicant of acetamiprid in the EU submitted new toxicology studies regarding the toxicological profile of the metabolite IM-2-1. Furthermore, the European Commission was made aware that several recent publications in scientific literature were made available after the literature searches conducted by EFSA. As the new data could affect the advice that EFSA was expected to deliver through the 2022 mandate, EFSA was further requested to consider this information by means of a revised mandate received in September 2023. As regards re-evaluation of point (i) in this statement, this was addressed by an EFSA Working Group integrating all the available evidence. The results of the weight of evidence indicated that there are major uncertainties in the body of evidence for the developmental neurotoxicity (DNT) properties of acetamiprid and further data are therefore needed to come to a more robust mechanistic understanding to enable appropriate hazard and risk assessment. In view of these uncertainties, the EFSA WG proposed to lower the acceptable daily intake (ADI) and acute reference dose (ARfD) from 0.025 to 0.005 mg/kg body weight (per day). A revised residue definition for risk assessment was proposed for leafy and fruit crops as sum of acetamiprid and N-desmethyl-acetamiprid (IM-2-1), expressed as acetamiprid. Regarding pulses/oilseeds, root crops and cereals, the new data received did not indicate a need to modify the existing residue definition for risk assessment, which therefore remains as parent acetamiprid. Regarding the residue definition for enforcement, the available data did not indicate a need to modify the existing definition because acetamiprid is still a sufficient marker of the residues in all crop groups. Considering the new health-based guidance values derived in the present statement, a risk for consumer has been identified for 38 MRLs currently in place in the EU Regulation. Consequently, EFSA recommended to lower the existing MRLs for 38 commodities based on the assessment of fall-back Good Agricultural Practices received within an ad hoc data call. Some fall-back MRLs proposals require further risk management considerations.

Exploratory analysis of the associations between neonicotinoids insecticides and serum lipid profiles among US adults: A cross-sectional, population-based study

Neonicotinoid insecticides (NNIs) are widely used in agriculture, horticulture, forestry, and household environment, but their potential impact on human health remains a subject of concern. This study aimed to investigate the relationship between NNIs and their metabolites in urine with serum lipid profiles in adults using data from the National Health and Nutrition Examination Survey (NHANES) 2015-2016. The study included 1192 participants aged over 20 years with urinary NNIs levels, serum lipid parameter levels and potential confounders. Urinary concentrations of NNIs, including imidacloprid, acetamiprid, clothianidin, thiacloprid, N-desmethyl-acetamiprid, and 5-hydroxy-imidacloprid, were quantified. Serum lipids profiles, such as total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B (Apo-B), were assessed. Considering the effects of lipid-lowering medications, the censored normal regression model was used to explore the associations between urinary NNIs and TC, TG, HDL-C, LDL-C and Apo-B levels. The results revealed a significant increase of 9.0 mg/dL (95%CI: 2.0, 16.1) in TC levels among participants with detectable N-desmethyl-acetamiprid compared to those with undetectable levels. Stratified analysis indicated that the association between N-desmethyl-acetamiprid and HDL-C levels was more pronounced among participants aged ≥ 46 years compared to those aged between 20 and 45 years with undetectable N-desmethyl-acetamiprid (pinteraction=0.044). Additionally, there were marginal effect modification of BMI on the association between N-desmethyl-acetamiprid and LDL-C (pinteraction=0.097) and Apo-B (pinteraction=0.052) levels. Specifically, participants with BMI ≥ 25 kg/m² and detectable N-desmethyl-acetamiprid tended to have higher LDL-C and Apo-B levels compared to those with BMI < 25 kg/m² and undetectable N-desmethyl-acetamiprid. However, no significant associations were observed between other NNIs and lipid profiles in the present study. To validate these findings, further longitudinal studies with larger sample sizes should be conducted, particularly within populations characterized by a high detection rate of NNIs.

Cytotoxicity, morphological and ultrastructural effects induced by the neonicotinoid pesticide, imidacloprid, using a rat Leydig cell line (LC-540)

Imidacloprid is a systemic neonicotinoid insecticide widely used to combat agricultural pests and flea infestations in dogs and cats. Despite its low toxicity to mammals, imidacloprid is reported to cause male reproductive toxicity. This study evaluated the cytotoxic effects of 75-800 μM imidacloprid on a rat Leydig cell line (LC-540). The effect of exposure to 300, 400, and 500 µM imidacloprid on selected cytoskeletal proteins, mitochondrial morphology, lysosomal acidity, and ultrastructure were investigated. Cell viability was markedly reduced after 48 and 72 h of exposure to higher imidacloprid concentrations. The immunocytochemical analysis revealed that the cytoskeletal filaments exhibited disorganization, disruption, and perinuclear aggregation in treated LC-540 cells. Ultrastructurally, cytoplasmic vacuoles, autophagic vacuoles, lysosomes, and mitochondrial damage were detected. Changes in the mitochondrial morphology and lysosomes induced by imidacloprid were confirmed. The cytotoxicity of imidacloprid observed in LC-540 cells might be due to its mitochondrial damage and cytoskeletal protein disruption.

Characterization of Environmental Levels of Pesticide Residues in Household Air and Dust Samples near a Bioenergy Plant Using Treated Seed as Feedstock

Exposure to neonicotinoid insecticides is associated with adverse human health outcomes. There is environmental contamination in Saunders County, Nebraska, due to the accumulation of fungicides and insecticides from a now-closed ethanol plant using seed corn as stock. A pilot study quantified environmental contamination in nearby houses from residual pesticides by measuring dust and air (indoor/outdoor) concentrations of neonicotinoids and fungicides at the study site (households within two miles of the plant) and control towns (20-30 miles away). Air (SASS® 2300 Wetted-Wall Air Sampler) and surface dust (GHOST wipes with 4 × 4-inch template) samples were collected from eleven study households and six controls. Targeted analysis quantified 13 neonicotinoids, their transformation products and seven fungicides. Sample extracts were concentrated using solid phase extraction (SPE) cartridges, eluted with methanol and evaporated. Residues were re-dissolved in methanol-water (1:4) prior to analysis, with an Acquity H-Class ultraperformance liquid chromatograph (UPLC) and a Xevo triple quadrupole mass spectrometer. We compared differences across chemicals in air and surface dust samples at the study and control sites by dichotomizing concentrations above or below the detection limit, using Fisher's exact test. A relatively higher detection frequency was observed for clothianidin and thiamethoxam at the study site for the surface dust samples, similarly for thiamethoxam in the air samples. Our results suggest airborne contamination (neonicotinoids and fungicides) from the ethanol facility at houses near the pesticide contamination.

Health risks of neonicotinoids chronic exposure and its association with glucose metabolism: A case-control study in rural China

Since neonicotinoids (NNIs) are widely used around the world, they are extensively distributed in the environment and frequently occurred in humans. This study was conducted to assess the risk of NNIs residues in vegetables and fruits in Henan province, and evaluate the associations of NNIs single and mixed exposure with glucose metabolism, and further explore whether testosterone mediated these relationships in Henan rural population. The data of vegetables and fruits were collected from Henan Province in 2020-2021, and participants were drawn from the Henan Rural Cohort study. Hazard quotient (HQ) and hazard index (HI) were used to assess the risk of exposure to the individual and combined NNIs through vegetables or fruits intake. Relative potency factor (RPF) method was utilized to normalize each NNIs to imidacloprid (IMIRPF). Generalized linear models were used to explore the effects of each NNIs and IMIRPF on glucose metabolism. Weight quartile sum (WQS) regression and Bayesian kernel machine regression (BKMR) model were applied to estimate the effect of NNIs mixtures on glucose metabolism. Mediation analysis was employed to explore whether testosterone mediated these relationships. The HQs and HI in both vegetables and fruits were much lower than 1, which indicated that NNIs in vegetables and fruits were not expected to cause significant adverse effects. However, plasma natural logarithm nitenpyram (Ln_NIT), Ln_thiacloprid-amid (Ln_THD-A), and Ln_IMIeq were positively associated with type 2 diabetes mellitus (T2DM) (odds ratio (OR) (95% confidence interval (CI)): 1.12 (1.05, 1.19), 1.21 (1.10, 1.32), and 1.48 (1.22, 1.80)). Both WQS regression and BKMR models observed significantly positive associations between NNIs mixture exposure and T2DM. Testosterone partially mediated these associations among women (PE = 6.67%). These findings suggest that human NNIs exposure may impair glucose metabolism and could contribute to rising rates of T2DM, and it's necessary to regulate the use of pesticides in rural areas.

Changing on the Concentrations of Neonicotinoids in Rice and Drinking Water through Heat Treatment Process

Neonicotinoids (NEOs) have become the most widely used insecticides in the world since the mid-1990s. According to Chinese dietary habits, rice and water are usually heated before being consumed, but the information about the alteration through the heat treatment process is very limited. In this study, NEOs in rice samples were extracted by acetonitrile (ACN) and in tap water, samples were extracted through an HLB cartridge, then, a high-performance liquid chromatography system and a triple quadrupole mass spectrometry (HPLC-MS/MS) were applied for target chemical analysis. The parents of NEOs (p-NEOs) accounted for >99% of the total NEOs mass (∑NEOs) in both uncooked (median: 66.8 ng/g) and cooked (median: 41.4 ng/g) rice samples from Guangdong Province, China, while the metabolites of NEOs (m-NEOs) involved in this study accounted for less than 1%. We aimed to reveal the concentration changes of NEOs through heat treatment process, thus, several groups of rice and water samples from Guangdong were cooked and boiled, respectively. Significant (p < 0.05) reductions in acetamiprid, imidacloprid (IMI), thiacloprid, and thiamethoxam (THM) have been observed after the heat treatment of the rice samples. In water samples, the concentrations of THM and dinotefuran decreased significantly (p < 0.05) after the heat treatment. These results indicate the degradation of p-NEOs and m-NEOs during the heat treatment process. However, the concentrations of IMI increased significantly in tap water samples (p < 0.05) after heat treatment process, which might be caused by the potential IMI precursors in those industrial pesticide products. The concentrations of NEOs in rice and water can be shifted by the heat treatment process, so this process should be considered in relevant human exposure studies.

Impact of endocrine disruptors from mother's diet on immuno-hormonal orchestration of brain development and introduction of the virtual human twin tool

Diet has long been known to modify physiology during development and adulthood. However, due to a growing number of manufactured contaminants and additives over the last few decades, diet has increasingly become a source of exposure to chemicals that has been associated with adverse health risks. Sources of food contaminants include the environment, crops treated with agrochemicals, inappropriate storage (e.g., mycotoxins) and migration of xenobiotics from food packaging and food production equipment. Hence, consumers are exposed to a mixture of xenobiotics, some of which are endocrine disruptors (EDs). The complex interactions between immune function and brain development and their orchestration by steroid hormones are insufficiently understood in human populations, and little is known about the impact on immune-brain interactions by transplacental fetal exposure to EDs via maternal diet. To help to identify the key data gaps, this paper aims to present (a) how transplacental EDs modify immune system and brain development, and (b) how these mechanisms may correlate with diseases such as autism and disturbances of lateral brain development. Attention is given to disturbances of the subplate, a transient structure of crucial significance in brain development. Additionally, we describe cutting edge approaches to investigate the developmental neurotoxicity of EDs, such as the application of artificial intelligence and comprehensive modelling. In the future, highly complex investigations will be performed using virtual brain models constructed using sophisticated multi-physics/multi-scale modelling strategies based on patient and synthetic data, which will enable a greater understanding of healthy or disturbed brain development.

Associations between neonicotinoids metabolites and hematologic parameters among US adults in NHANES 2015-2016

Hematologic parameters are important indicators for monitoring the physiological changes and human health. Neonicotinoids (NEOs) exhibit toxic effects and can affect hematologic parameters. However, the effects of exposure to NEOs metabolites on hematologic parameters in the general population remain unknown. We examined the relationship between NEOs metabolites and hematologic parameters using a cross-sectional study design in 1397 adults of the National Health and Nutrition Examination Survey (NHANES) 2015-2016. The levels of NEOs metabolites in urine and hematologic makers were measured. Multivariate linear regression models were performed to examine the relationship between exposure to NEOs metabolites and hematologic parameters. Detectable urine levels of clothianidin (CLO) was inversely associated with hematocrit (β =  - 0.689; 95% CI: - 1.335, - 0.042). Detectability of 5-hydroxy-imidacloprid (HIMI) was inversely correlated with basophil percentage (β =  - 0.093; 95% CI: - 0.180, - 0.007). N-Desmethyl-acetamiprid (NDE) was related to reduced white blood cells (WBC) (β =  - 0.419; 95% CI: - 0.764, - 0.074) and neutrophil counts (β =  - 0.349; 95% CI: - 0.623, - 0.074). Imidacloprid-equivalent total neonicotinoids (IMIeq) was negatively related to red blood cells (RBC) (β =  - 0.058; 95% CI: - 0.097, - 0.020), hemoglobin (β =  - 0.149; 95% CI: - 0.282, - 0.015), and hematocrit (β =  - 0.484; 95% CI: - 0.855, - 0.113). We also observed that exposure to NEOs metabolites was sex specifically related to hematologic alterations. For example, IMIeq was associated with reduced basophil counts (β =  - 0.016; 95% CI: - 0.028, - 0.003), basophil percentage (β =  - 0.092; 95% CI: - 0.169, - 0.016), RBC (β =  - 0.097; 95% CI: - 0.156, - 0.038), hemoglobin (β =  - 0.200; 95% CI: - 0.355, - 0.045), and hematocrit (β =  - 0.605; 95% CI: - 1.111, - 0.098) only in males. These results provide the first evidence that exposure to NEOs metabolites can disturb hematologic homeostasis in the general population, and the effects may be sex specific.