Neonicotinoids and carbendazim in indoor dust from three cities in China: Spatial and temporal variations

Microbial degradation of contaminants of emerging concern: metabolic, genetic and omics insights for enhanced bioremediation

The perpetual release of natural/synthetic pollutants into the environment poses major risks to ecological balance and human health. Amongst these, contaminants of emerging concern (CECs) are characterized by their recent introduction/detection in various niches, thereby causing significant hazards and necessitating their removal. Pharmaceuticals, plasticizers, cyanotoxins and emerging pesticides are major groups of CECs that are highly toxic and found to occur in various compartments of the biosphere. The sources of these compounds can be multipartite including industrial discharge, improper disposal, excretion of unmetabolized residues, eutrophication etc., while their fate and persistence are determined by factors such as physico-chemical properties, environmental conditions, biodegradability and hydrological factors. The resultant exposure of these compounds to microbiota has imposed a selection pressure and resulted in evolution of metabolic pathways for their biotransformation and/or utilization as sole source of carbon and energy. Such microbial degradation phenotype can be exploited to clean-up CECs from the environment, offering a cost-effective and eco-friendly alternative to abiotic methods of removal, thereby mitigating their toxicity. However, efficient bioprocess development for bioremediation strategies requires extensive understanding of individual components such as pathway gene clusters, proteins/enzymes, metabolites and associated regulatory mechanisms. "Omics" and "Meta-omics" techniques aid in providing crucial insights into the complex interactions and functions of these components as well as microbial community, enabling more effective and targeted bioremediation. Aside from natural isolates, metabolic engineering approaches employ the application of genetic engineering to enhance metabolic diversity and degradation rates. The integration of omics data will further aid in developing systemic-level bioremediation and metabolic engineering strategies, thereby optimising the clean-up process. This review describes bacterial catabolic pathways, genetics, and application of omics and metabolic engineering for bioremediation of four major groups of CECs: pharmaceuticals, plasticizers, cyanotoxins, and emerging pesticides.

The mother-offspring transfer of chlorothalonil through human breast milk: A multi-city cross-sectional study

4-Hydroxychlorothalonil (4-OH CHT), the main metabolite of chlorothalonil and the most widely used fungicide, has been frequently detected in human samples during monitoring. 4-OH CHT may exhibit higher toxicity and persistence in the environment compared to its prototype. In this study, a total of 540 paired serum and breast milk samples from pregnant women in three provinces in China were monitored for contaminant residues. 4-OH CHT was analyzed in the samples using ultra high-performance liquid chromatography - high-resolution mass spectrometry with a detection limit of 20 ng/L. The study investigated the effects of demographic factors, such as BMI, region of residence, and education level, on the levels of 4-OH CHT residues in serum and breast milk. Among the three provinces, the highest median concentration of 4-OH CHT in serum samples was observed in Hebei (1.04 × 103 ng/L), while the highest median concentration of 4-OH CHT in breast milk samples was observed in Hubei and Guangdong (491 ng/L). Multiple linear regression was used to investigate the significant positive correlation between 4-OH CHT in serum and breast milk (p = 0.000) after adjusting for personal characteristics. Based on this, the study further explored the influencing factors of transfer efficiencies (TEs) in conjunction with the individual TEs and the personal characteristics of the participants. Our results demonstrated that the age of the volunteers and their exercise habits had an effect on TEs, but further studies are needed to determine whether exercise leads to an increase in TEs.

Associations between neonicotinoid insecticide levels in follicular fluid and serum and reproductive outcomes among women undergoing assisted reproductive technology: An observational study

Neonicotinoid insecticides (NEOs) are a widely used type of insecticide found globally, leading to broad human exposure. However, there is limited research on how internal exposure levels of NEOs and their metabolites impact in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes. A study was conducted at the Sixth Affiliated Hospital of Sun Yat-sen University between 2017 and 2020 involving 436 women undergoing IVF/ICSI treatment. Data on demographics and clinical history were collected from medical records. The concentrations of 11 NEOs and 4 NEO metabolites in follicular fluid and serum were measured using a salting-out assisted liquid-liquid extraction method and liquid chromatography-tandem mass spectrometry. Our findings indicated that NEOs were prevalent in women with infertility. One NEO metabolite, N-dm-ACE, was detected in all samples with median concentrations of 0.221 ng/mL in follicular fluid and 0.228 ng/mL in serum. The study showed a decrease in the number of retrieved oocytes, mature oocytes, 2 PN zygotes, and high-quality embryos as the number of exposed NEOs in follicular fluid increased. Women in the highest tertile of N-dm-ACE exposure had fewer mature oocytes, 2 PN zygotes, and lower oocyte maturity rates compared to those in the lowest tertile. The findings suggest that exposure to NEOs may negatively impact reproductive outcomes in IVF/ICSI pregnancies, particularly affecting oocyte retrieval and embryo quality. This study highlights the potential adverse effects of environmental NEO exposure on IVF/ICSI outcomes, emphasizing the importance of considering such exposures in preconception care.

Neonicotinoids as emerging contaminants in China's environment: a review of current data

Neonicotinoids (NEOs), the most widely used class of insecticides, are pervasive in the environment, eliciting concerns due to their hydrophilicity, persistence, and potential ecological risks. As the leading pesticide consumer, China shows significant regional disparities in NEO contamination. This review explores NEO distribution, sources, and toxic risks across China. The primary NEO pollutants identified in environmental samples include imidacloprid, thiamethoxam, and acetamiprid. In the north, corn cultivation represents the principal source of NEOs during wet seasons, while rice dominates in the south year-round. The high concentration levels of NEOs have been detected in the aquatic environment in the southern regions (130.25 ng/L), the urban river Sects. (157.66 ng/L), and the downstream sections of the Yangtze River (58.9 ng/L), indicating that climate conditions and urban pollution emissions are important drivers of water pollution. Neonicotinoids were detected at higher levels in agricultural soils compared to other soil types, with southern agricultural areas showing higher concentrations (average 27.21 ng/g) than northern regions (average 12.77 ng/g). Atmospheric NEO levels were lower, with the highest concentration at 1560 pg/m3. The levels of total neonicotinoid pesticides in aquatic environments across China predominantly exceed the chronic toxicity ecological threshold of 35 ng/L, particularly in the regions of Beijing and the Qilu Lake Basin, where they likely exceed the acute toxicity ecological threshold of 200 ng/L. In the future, efforts should focus on neonicotinoid distribution in agriculturally developed regions of Southwest China, while also emphasizing their usage in urban greening and household settings.

Spatiotemporal variation, fluxes and risk evaluation of neonicotinoid insecticides within the midsection of Yangtze River, China: An exploration as ecological protection threshold

Neonicotinoid insecticides (NNIs) have attracted global concern due to its extensive use in agricultural activities and their potential risks to the animal and human health, however, there is limited knowledge on the regional traits and ecological risks of NNIs in the aquatic environments. We herein investigated the occurrence of NNIs within the midsection of Yangtze River in China, offering the inaugural comprehensive report on NNIs within this region. In this study, eleven NNIs were analyzed in 108 river water and sediment samples from three seasons (normal, dry and wet season). We detected a minimum of seven NNIs in the water and four NNIs in the sediment, with total concentrations ranging from 12.33 to 100.5 ng/L in water and 0.08-5.68 ng/g in sediment. The levels of NNIs in both river water and sediment were primarily influenced by the extent of agricultural activities. The estimated annual load of NNIs within the midsection of Yangtze River totaled 40.27 tons, April was a critical contamination period. Relative potency factor (RPF) analysis of the human exposure risk revealed that infants faced the greatest exposure risk, with an estimated daily intake of 11.27 ng kg-1∙bw∙d-1. We established the acute and chronic thresholds for aquatic organisms by employing the Species Sensitive Distribution (SSD) method (acute: 384.1 ng/L; chronic: 168.9 ng/L). Based on the findings from this study, 33% of the river water samples exceeded the chronic ecological risks thresholds, indicating the urgent need for intervention programs to guarantee the safety of the river for aquatic life in the Yangtze River Basin.

Associations between neonicotinoids and liver function measures in US adults: National Health and Nutrition Examination Survey 2015-2016

Background

Toxicological studies indicate that neonicotinoids may be associated with disruptions in liver function due to an increase in oxidative stress. There are scant epidemiological studies investigating the chronic hepatotoxic effects of neonicotinoids.

Objective

To examine the association between detectable concentrations of parent neonicotinoids and neonicotinoid metabolites with liver function markers among US adults, and whether sex modifies this association.

Methods

National Health and Nutrition Examination Survey 2015-2016 data were used to estimate associations between detectable neonicotinoids and serum alkaline phosphatase (ALP), alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transaminase (GGT), albumin, total bilirubin, total protein, and Hepatic Steatosis Index (HSI) using multiple linear regression.

Results

Detectable levels of N-desmethyl-acetamiprid were associated with a decrease in GGT (β = -3.54 unit/l; 95% confidence interval [CI] = -6.48, -0.61) and detectable levels of 5-hydroxy-imidacloprid were associated with a decrease in HSI (β = -1.11; 95% CI = -2.14, -0.07). Sex modified the association between any parent neonicotinoid and ALP (Pint = 0.064) and the association between clothianidin and ALP (Pint = 0.019), with a pattern of positive associations in males and inverse associations in females, though stratified associations did not reach statistical significance. Sex also modified the association between 5-hydroxy-imidacloprid and total protein (Pint = 0.062), with a significant positive association in females (β = 0.14 g/dl; 95% CI = 0.03, 0.25) and a null association in males.

Conclusion

Detectable concentrations of neonicotinoid metabolites were inversely associated with GGT and HSI in US adults. Evidence suggests neonicotinoids may influence liver function differently depending on sex. Future research is recommended to replicate the findings as the study was limited in its cross-sectional nature and inability to examine continuous neonicotinoid concentrations with liver function.

Swellable microneedle-coupled light-addressable photoelectrochemical sensor for in-situ tracking of multiple pesticides pollution in vivo

In vivo monitoring of multiple pesticide contamination is of great significance for evaluating the health risks of different pesticides, agricultural production safety, and ecological and environmental assessment. Here, we report a hydrogel microneedle array coupled light-addressable photoelectrochemical sensor for tracking multiple pesticide uptake and elimination in living animals and plants, holding three prominent merits: i) enables in-situ detection of in vivo pesticides, avoiding cumbersome and complex sample transportation and handling processes; ii) allows repeated in vivo sampling of the same organism, improving tracking test controllability and accuracy; iii) avoids lethal sampling, providing a better understanding of the pesticides fate in living organisms. The coupled sensor is mechanically robust for withstanding more than 0.35 N per needle and highly swellable (800 %) for timely extraction of sufficient in vivo solution for analysis. For proof-of-concept, it achieves in-situ detection of atrazine, acetamiprid, and carbendazim efficiently and quantitatively in artificial agarose skin models, mouse skin interstitial fluids, and plant leaves with little inflammatory reaction. This simple, highly integrated, minimally invasive, and high-throughput in vivo monitoring method is ideal for future field environmental monitoring and plant and animal disease diagnosis.

Identification of key factors affecting neonicotinoid residues in crops and risk of dietary exposure

Neonicotinoids, widely used on farmland, are ubiquitous in food; however, their distribution among various crops and associated exposure risks at the provincial level in China remain unclear. We collected 19 types of crop samples (fruits, vegetables, and tea) from farmland in nine prefectural cities in Zhejiang Province, China. We analyzed nine commonly used neonicotinoids in the edible portions of these crops. A notable detection rate (42.1 %-82.9 %) and high residual neonicotinoid concentrations (278 ± 357 ng/g) were observed. Tea exhibited the highest residue, followed by fruits, and vegetables showed the lowest (P < 0.05). Neonicotinoid ratios in crops to soil (R_C/S) and soil to water (R_S/W) were defined to discern insecticide distribution across different environments. Increased water solubility leads to increased migration of neonicotinoids (R_S/W) from agricultural soils to water through runoff, thereby increasing the relative contribution of nitenpyram and dinotefuran in water. In comparison with other studied compounds, all crops demonstrated the strongest soil uptake of thiamethoxam, denoted by the highest R_C/S value. Elevated R_C/S values in tea, pickled cabbage, and celery suggest increased susceptibility of these crops to neonicotinoid absorption from the soil (P < 0.05). Estimated dietary intake for teenagers, adults and elders was 8.9 ± 0.5, 8.9 ± 0.6, and 8.8 ± 0.3 μg/kg/d, respectively, below the reference dose (57 μg/kg/d). Teenagers, compared to adults and elders, exhibited significantly higher neonicotinoid exposure through fruit consumption, emphasizing the need for increased attention to neonicotinoid exposure among vulnerable populations.

Non-acute exposure of neonicotinoids, health risk assessment, and evidence integration: a systematic review

Neonicotinoid pesticides are utilized against an extensive range of insects. A growing body of evidence supports that these neuro-active insecticides are classified as toxicants in invertebrates. However, there is limited published data regarding their toxicity in vertebrates and mammals. the current systematic review is focused on the up-to-date knowledge available for several neonicotinoid pesticides and their non-acute toxicity on rodents and human physiology. Oral lethal dose 50 (LD50) of seven neonicotinoids (i.e. imidacloprid, acetamiprid, clothianidin, dinotefuran, thiamethoxam, thiacloprid, and nitenpyram) was initially identified. Subsequently, a screening of the literature was conducted to collect information about non-acute exposure to these insecticides. 99 studies were included and assessed for their risk of bias and level of evidence according to the Office of Health and Translation (OHAT) framework. All the 99 included papers indicate evidence of reproductive toxicity, hepatotoxicity, nephrotoxicity, neurotoxicity, immunotoxicity, and oxidative stress induction with a high level of evidence in the health effect of rodents and a moderate level of evidence for human health. The most studied type of these insecticides among 99 papers was imidacloprid (55 papers), followed by acetamiprid (22 papers), clothianidin (21 papers), and thiacloprid (11 papers). While 10 of 99 papers assessed the relationship between clothianidin, thiamethoxam, dinotefuran, and nitenpyram, showing evidence of liver injury, dysfunctions of oxidative stress markers in the reproductive system, and intestinal toxicity. This systematic review provides a comprehensive overview of the potential risks caused by neonicotinoid insecticides to humans and rodents with salient health effects. However, further research is needed to better emphasize and understand the patho-physiological mechanisms of these insecticides, taking into account various factors that can influence their toxicity.

Urinary biomarkers of exposure to organophosphate, pyrethroid, neonicotinoid insecticides and oxidative stress: A repeated measurement analysis among pregnant women

Exposure to insecticides may be associated with increased oxidative stress (OS), but few studies have assessed the associations of OS biomarkers (OSBs) with exposure to multiple insecticides and their mixture, especially in pregnant women who are a vulnerable population. In the present study, 1,094 Chinese pregnant women were recruited and a total of 3,282 urine samples were collected at their three trimesters to measure eight metabolites of organophosphates, three metabolites of pyrethroids, nine typical neonicotinoids/their metabolites, and three OSBs of DNA damage (8-OHdG), RNA damage (8-OHG), and lipid peroxidation (HNE-MA). Among the twenty target insecticide metabolites, sixteen of them were frequently detected; thirteen of them were detected in over 86% of all the urine samples except for imidacloprid (IMI, detection frequency: 72.9%), desnitro-imidacloprid (DN-IMI, 70.0%), and clothianidin (CLO, 79.6%). The reproducibility of their concentrations across the three trimesters was poor to fair (intraclass correlation coefficients <0.50). Multiparity and warm season were related to higher urinary levels of some insecticide metabolites, while higher education level and inadequate weight gain during pregnancy were significantly associated with lower concentrations of certain insecticide metabolites. Linear mixed model analyses suggested that almost all the frequently detected insecticide metabolites [other than 3-phenoxybenzoic acid (3-PBA)] were significantly associated with elevated levels of the three OSBs (8-OHdG, 8-OHG, and HNE-MA), where the percent change (Δ%) ranged 8.10-36.0% for 8-OHdG, 8.49-34.7% for 8-OHG, and 5.92-182% for HNE-MA, respectively, with each interquartile ratio (IQR)-fold increase in the concentrations of the individual exposure biomarkers. Weighted quantile sum models demonstrated that the insecticide metabolite mixture was positively associated with the three OSBs. Overall, urinary desmethyl-clothianidin (DM-CLO) and 3,5,6-trichloro-2-pyridinol (TCPy) were the top insecticide exposure biomarkers contributing to the association with 8-OHdG and 8-OHG levels, while PNP contributed the most to the association with HNE-MA levels. These findings suggested that gestational exposure to organophosphates, pyrethroids, neonicotinoids, their transformation products, and their mixture may increase oxidative damage to lipids, RNA, and DNA during pregnancy.

Neonicotinoids Persisting in the Sea Pose a Potential Chronic Risk to Marine Organisms: A Case from Xiangshan Bay, China (2015-2019)

Neonicotinoid insecticides (neonics) are extensively employed in agriculture and pervade various environmental matrices. However, few studies have documented the occurrence and potential chronic ecological risks of these chemicals in the marine environment. We collected 720 seawater samples from Xiangshan Bay during 2015-2019 and the integrated concentrations of seven neonics were determined using the relative potency factor method. Trend analyses using the Mann-Kendall test in time series, along with the estimation of the flux of neonics into the sea, were conducted. At last, the ecological risk of neonics was evaluated by water quality criteria derivation based on species sensitivity distribution. Our findings revealed that 47.6% of samples contained at least one neonic, with the integrated concentration of neonics ranging from 63.30 to 1684.14 ng/L. Imidacloprid and dinotefuran exhibited the highest frequency of detection in the analysis. The significance level of the Mann-Kendall test ranged from 2.16 × 10-10 to 1.21 × 10-5 (S > 0), indicating all neonics behaved with sharply increasing trends. Approximately 8.47 × 10-2 tons of neonics were discharged into Xiangshan Bay. Notably, the integrated concentrations of neonics represented a potential chronic ecological risk to marine organisms. This study provided novel insights into the spatial distribution, source, and migration of neonic species and their impacts on marine ecosystems.

Pesticide residues in adults living near a bioenergy plant with 85,000 tons of contaminated wetcake

Neonicotinoid insecticide use is on the rise worldwide due to its broad-spectrum insecticidal action and exclusive approach of neurotoxic action. Besides application during the cultivation of several crops, all seed companies coat their seeds with neonicotinoids to have increased protection against insects during germination. Despite reduced mammalian toxicity, neonicotinoids have harmful effects on non-target non-mammalian organisms such as bees, an essential part of maintaining the ecosystem. In addition, epidemiologic studies have linked human exposure to neonicotinoids with poor developmental and neurological outcomes. Starting in 2015, the AltEn bioenergy plant near Mead, Nebraska, USA, used coated seeds for their ethanol production and failed to properly dispose of byproducts, causing environmental contamination that still exists. This pilot study reports the human urinary levels of neonicotinoids in samples collected during 2022-2023 in the population living in areas close to this now-closed bioenergy plant. Our results show that approximately 30% of the urine samples are contaminated with at least one of the targeted neonicotinoids or their transformed products. The most frequently detected parent neonicotinoid was clothianidin, which accounts for 13% of the samples. However, 5-hydroxy-imidacloprid, the transformed imidacloprid product, is detected in 27% of the samples, ranging from 1.2 to 42 ng/mL. In conclusion, the environmental contamination near Mead, Nebraska, due to improper storage and disposal of highly contaminated byproducts, puts the nearby population at risk from continuous exposure to neonicotinoids through air and dust particles and possible water contamination.

Occurrence of pesticide residues in indoor dust of farmworker households across Europe and Argentina

Pesticides are widely used as plant protection products (PPPs) in farming systems to preserve crops against pests, weeds, and fungal diseases. Indoor dust can act as a chemical repository revealing occurrence of pesticides in the indoor environment at the time of sampling and the (recent) past. This in turn provides information on the exposure of humans to pesticides in their homes. In the present study, part of the Horizon 2020 funded SPRINT project, the presence of 198 pesticide residues was assessed in 128 indoor dust samples from both conventional and organic farmworker households across Europe, and in Argentina. Mixtures of pesticide residues were found in all dust samples (25-121, min-max; 75, median). Concentrations varied in a wide range (<0.01 ng/g-206 μg/g), with glyphosate and its degradation product AMPA, permethrin, cypermethrin and piperonyl butoxide found in highest levels. Regarding the type of pesticides, insecticides showed significantly higher levels than herbicides and fungicides. Indoor dust samples related to organic farms showed a significantly lower number of residues, total and individual concentrations than those related to conventional farms. Some pesticides found in indoor dust were no longer approved ones (29 %), with acute/chronic hazards to human health (32 %) and with environmental toxicity (21 %).

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.

Association between urinary neonicotinoid insecticide levels and dyslipidemia risk: A cross-sectional study in Chinese community-dwelling elderly

Experimental evidence has demonstrated that neonicotinoids (NEOs) exposure can cause lipid accumulation and increased leptin levels. However, the relationship between NEOs exposure and dyslipidemia in humans remains unclear, and the interactive effects of NEOs and their characteristic metabolites on dyslipidemia remain unknown. We detected 14 NEOs and their metabolites in urine samples of 500 individuals (236 and 264 with and without dyslipidemia, respectively) randomly selected from the baseline of the Yinchuan community-dwelling elderly cohort (Ningxia, China). The NEOs and their metabolites were widely detected in urine (87.2-99.6 %) samples, and the median levels ranged within 0.06-0.55 μg/g creatinine. The positive associations and dose-dependent relationships of thiacloprid, imidacloprid-olefin, and imidacloprid-equivalent total with dyslipidemia were validated using restricted cubic spline analysis. Mixture models revealed a positive association between the NEOs mixture and dyslipidemia risk, with urine desnitro-imidacloprid ranked as the top contributor. The Bayesian Kernel Machine Regression models showed that the NEOs mixtures were associated with increased dyslipidemia when the chemical mixtures were ≥ 25th percentile compared to their medians, and desnitro-imidacloprid and imidacloprid-olefin were the major contributors to the combined effect. Given the widespread use of NEOs and the dyslipidemia pandemic, further investigations are urgently needed to confirm our findings and elucidate the underlying mechanisms.

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.

Exposure to multiple neonicotinoid insecticides, oxidative stress, and gestational diabetes mellitus: Association and potential mediation analyses

As the most extensively used insecticides worldwide, neonicotinoid insecticides (NNIs) have received a growing global concern over their adverse health effects. This study aimed to assess the associations of urinary concentrations of NNIs in early pregnancy with gestational diabetes mellitus (GDM) and the mediation roles of oxidative DNA damage, RNA damage, and lipid peroxidation in the associations. With a prospective nested case-control study, 519 GDM cases and 519 controls were matched on the infant's sex and maternal age. Urinary biomarkers of NNIs exposure and oxidative stress were measured in early pregnancy. We estimated the associations of single and the mixture of NNIs and their metabolites with GDM by conditional logistic regression and quantile g-computation models, respectively. The mediating roles of oxidative stress were evaluated by the structural equation model. The odds of GDM significantly increased by 15 %, 18 %, 26 %, 42 %, 49 %, and 13 % in each unit increment of ln-transformed concentrations of urinary imidacloprid (IMI), imidacloprid-olefin (IMI-olefin), desnitro-imidacloprid (DN-IMI), thiamethoxam (THM), clothianidin, and desmethyl-clothianidin, respectively. Exposure to the mixture of NNIs was associated with increased odds of GDM (adjusted OR: 1.76; 95 %CI: 1.45, 2.13). Advanced maternal age enhanced the associations of 5-hydroxy-IMI, DN-IMI, and IMI-olefin with GDM (P < 0.05), and being overweight/obese before pregnancy strengthened the effects of IMI, IMI-olefin, and THM on GDM (P < 0.05). In the association of NNIs exposure and GDM, the proportions mediated by oxidative DNA damage, RNA damage, and overall oxidative stress were 9.8 %, 11.8 %, and 14.5 %, respectively (P < 0.05). Exposure to individual NNIs and a mixture of NNIs were associated with GDM, and maternal age and pre-pregnancy BMI may modify the association. The possible mechanism underlying the association between NNIs and GDM may involve oxidative damage to nucleic acids.

Neonicotinoid insecticides and their metabolites: Specimens tested, analytical methods and exposure characteristics in humans

The use of neonicotinoid insecticides (NEOs) has been rising globally due to their broad-spectrum insecticidal activity, unique mode of neurotoxic action and presumed low mammalian toxicity. Given their growing ubiquity in the environment and neurological toxicity to non-target mammals, human exposure to NEOs is flourishing and now becomes a big issue. In the present work, we demonstrated that 20 NEOs and their metabolites have been reported in different human specimens with urine, blood and hair as the dominance. Sample pretreatment techniques of solid-phase and liquid-liquid extractions coupled with high performance liquid chromatography-tandem mass spectrometry have successfully achieved matrix elimination and accurate analysis. We also discussed and compared exposure characteristics of these compounds among types of specimens and different regions. A number of important knowledge gaps were also identified in order to further facilitate the understanding of health effects of NEO insecticides, which include, but are not limited to, identification and use of neuro-related human biological samples for better elucidating neurotoxic action of NEO insecticides, adoption of advanced non-target screening analysis for a whole picture in human exposure, and expanding investigations to cover non-explored but NEO-used regions and vulnerable populations.

Urinary neonicotinoid insecticides and adiposity measures among 7-year-old children in northern China: A cross-sectional study

BACKGROUND

Neonicotinoid insecticides (NEOs) are emerging synthetic insecticides used in various pest management regimens worldwide. Toxicology studies have indicated the obesogenic potential of NEOs, but their associations with adiposity measures are largely unknown.

OBJECTIVES

We aimed to assess urinary levels of NEOs/metabolites and their associations with children's adiposity measures, and to further investigate the potential role of oxidative stress.

METHODS

This study included 380 children who participated in the 7th year's follow-up of the Laizhou Wan Birth Cohort in northern China. Urinary levels of seven NEOs and two metabolites and a biomarker of lipid peroxidation named 8-iso-prostaglandin-F2α (8-iso-PGF2α) were detected. A total of nine indicators of adiposity were measured. Body mass index (BMI) z-score ≥85th percentile was defined as overweight/obesity, and waist-to-height ratio (WHtR) ≥0.5 was considered as abdominal obesity. Multiple linear regression, binary logistic regression and mediation analysis were performed.

RESULTS

Six NEOs [imidacloprid (IMI, 99.7%), clothianidin (CLO, 98.9%), dinotefuran (DIN, 97.6%), thiamethoxam (THM, 95.5%), acetamiprid (ACE, 82.9%), thiacloprid (THD, 77.6%)] and two metabolites [N-desmethyl-acetamiprid (N-DMA, 100.0%), 6-chloronicotinic acid (6-CINA, 97.9%)] exhibited high detection rates. Multiple linear regressions showed positive associations of waist circumference with urinary levels of IMI and THM, of WHtR with IMI and THM levels, and of body fat percentage with 6-CINA levels. In contrast, exposure to N-DMA was negatively associated with body fat percentage and fat mass index. Binary logistic regressions further revealed that higher IMI levels were associated with overweight/obesity (OR = 1.556, 95% CI: 1.100, 2.201) and abdominal obesity (OR = 1.478, 95% CI: 1.078, 2.026) in children. 8-iso-PGF2α demonstrated 27.92%, 69.52% and 35.37% mediating effects in the positive associations of IMI, THD and THM with WHtR, respectively. Sex modified the associations of DIN with body fat mass (p_int = 0.032), body fat percentage (p_int = 0.009), fat mass index (p_int = 0.037) and the overweight/obesity rate (p_int = 0.046), with negative associations in girls and nonsignificant positive associations in boys.

CONCLUSIONS

School-age children in northern China were widely exposed to NEOs/metabolites. Urinary levels of NEOs/metabolites were associated with adiposity measures through the mediating role of 8-iso-PGF2α. These associations were mixed, and a sex-specific effect might exist.

Endocrine disrupting chemicals in indoor dust: A review of temporal and spatial trends, and human exposure

Several chemicals with widespread consumer uses have been identified as endocrine-disrupting chemicals (EDCs), with a potential risk to humans. The occurrence in indoor dust and resulting human exposure have been reviewed for six groups of known and suspected EDCs, including phthalates and non-phthalate plasticizers, flame retardants, bisphenols, per- and polyfluoroalkyl substances (PFAS), biocides and personal care product additives (PCPs). Some banned or restricted EDCs, such as polybrominated diphenyl ethers (PBDEs), di-(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), are still widely detected in indoor dust in most countries, even as the predominating compounds of their group, but generally with decreasing trends. Meanwhile, alternatives that are also potential EDCs, such as bisphenol S (BPS), bisphenol F (BPF), decabromodiphenyl ethane (DBDPE) and organophosphate flame retardants (OPFRs), and PFAS precursors, such as fluorotelomer alcohols, have been detected in indoor dust with increasing frequencies and concentrations. Associations between some known and suspected EDCs, such as phthalate and non-phthalate plasticizers, FRs and BPs, in indoor dust and paired human samples indicate indoor dust as an important human exposure pathway. Although the estimated daily intake (EDI) of most of the investigated compounds was mostly below reference values, the co-exposure to a multitude of known or suspected EDCs requires a better understanding of mixture effects.

Prevalence of neonicotinoid insecticides in paired private-well tap water and human urine samples in a region of intense agriculture overlying vulnerable aquifers in eastern Iowa

A pilot study among farming households in eastern Iowa was conducted to assess human exposure to neonicotinoids (NEOs). The study was in a region with intense crop and livestock production and where groundwater is vulnerable to surface-applied contaminants. In addition to paired outdoor (hydrant) water and indoor (tap) water samples from private wells, urine samples were collected from 47 adult male pesticide applicators along with the completions of dietary and occupational surveys. Estimated Daily Intake (EDI) were then calculated to examine exposures for different aged family members. NEOs were detected in 53% of outdoor and 55% of indoor samples, with two or more NEOs in 13% of samples. Clothianidin was the most frequently detected NEO in water samples. Human exposure was ubiquitous in urine samples. A median of 10 different NEOs and/or metabolites were detected in urine, with clothianidin, nitenpyram, thiamethoxam, 6-chloronicotinic acid, and thiacloprid amide detected in every urine samples analyzed. Dinotefuran, imidaclothiz, acetamiprid-N-desmethyl, and N-desmethyl thiamethoxam were found in ≥70% of urine samples. Observed water intake for study participants and EDIs were below the chronic reference doses (CRfD) and acceptable daily intake (ADI) standards for all NEOs indicating minimal risk from ingestion of tap water. The study results indicate that while the consumption of private well tap water provides a human exposure pathway, the companion urine results provide evidence that diet and/or other exposure pathways (e.g., occupational, house dust) may contribute to exposure more than water contamination. Further biomonitoring research is needed to better understand the scale of human exposure from different sources.

The partitioning and distribution of neonicotinoid insecticides in human blood

The burden of neonicotinoid insecticides (neonics) in humans has attracted widespread attention in recent years due to the potential adverse effects. Nonetheless, information on the partitioning behavior and distribution in human blood is still limited. Herein, we obtained 115 adult whole blood and plasma specimens for analysis of eight neonics to better understand neonics' partitioning and distribution in human blood. At least one neonic was detected in 49.6% of the red blood cells and 55.7% of the plasma. In red blood cells, the highest detection rate and concentration was thiamethoxam (THI) with 19.1% and 3832 ng/L, respectively. Imidacloprid had the highest detection rate with 26.1% in the plasma. The mass fraction (Fp) of neonics detected indicates that thiacloprid, imidacloprid, and dinotefuran are mostly resided in plasma upon entering into human blood, while thiamethoxam is mostly present in red blood cells. The distribution of clothianidin and acetamiprid between plasma and red blood cells is similar. The mass fraction (Fp) values for THI were significantly different compared to other neonics, and the effect of age and gender on THI partitioning concluded that there may not be significant variability in the distribution of THI in the sampled population. Overall, this study was the first to investigate neonics residuals in red blood cells and provided fundamental information on the partitioning and distribution of neonics in human blood.

Urinary concentrations of fungicide carbendazim's metabolite and associations with oxidative stress biomarkers in young children

Carbendazim (CBDZ) is the most widely used fungicide in China. It is ubiquitous in environment and can induce oxidative stress in mammals, while data on occurrence of its metabolite in human urine are scarce, and the relationship between CBDZ and oxidative stress biomarkers (OSBs) in young children has not been examined. The aim of this study was to measure the concentrations of methyl 5-hydroxy-2-benzimidazolecarbamate (5-HBC, the main metabolite of CBDZ in urine) in 390 urine samples collected from 130 healthy young (< 6.6 years old) children from Shenzhen and Wuhan, in south and central China, respectively, and to evaluate the associations of 5-HBC with three selected OSBs (4-HNEMA, 8-OHG, and 8-OHdG, for lipid, RNA, and DNA, respectively). 5-HBC was found in 99.2% of the urine samples at concentrations ranging from below the method detection limit (< 0.005 ng/mL) to 10.9 ng/mL (median: 0.11 ng/mL). Moderate inter-day reproducibility was found for specific gravity-adjusted 5-HBC concentrations (intraclass correlation coefficient: 0.50). The urinary 5-HBC concentrations were significantly and positively associated with 4-HNEMA (p < 0.01). An interquartile range increase in urinary 5-HBC concentrations was associated with a 42.1% increase in 4-HNEMA, which implied that CBDZ exposure might be associated with lipid peroxidation in young children without occupational exposure. As far as we know, this pilot study is the first to report urinary 5-HBC and its associations with OSBs in children.

Neonicotinoid Insecticides and Their Metabolites Can Pass through the Human Placenta Unimpeded

Studies on neonicotinoid (NEO) exposure in pregnant women and fetuses are scarce, and transplacental transfer of these insecticides is unknown. In this study, parent NEOs (p-NEOs) and their metabolites (m-NEOs) were determined in 95 paired maternal (MS) and cord serum (CS) samples collected in southern China. Imidacloprid was the predominant p-NEO in both CS and MS samples, found at median concentrations of 1.84 and 0.79 ng/mL, respectively, whereas N-desmethyl-acetamiprid was the most abundant m-NEO in CS (median: 0.083 ng/mL) and MS (0.13 ng/mL). The median transplacental transfer efficiencies (TTEs) of p-NEOs and m-NEOs were high, ranging from 0.81 (thiamethoxam, THM) to 1.61 (olefin-imidacloprid, of-IMI), indicating efficient placental transfer of these insecticides. Moreover, transplacental transport of NEOs appears to be passive and structure-dependent: cyanoamidine NEOs such as acetamiprid and thiacloprid had higher TTE values than the nitroguanidine NEOs, namely, clothianidin and THM. Multilinear regression analysis revealed that the concentrations of several NEOs in MS were associated significantly with hematological parameters related to hepatotoxicity and renal toxicity. To our knowledge, this is the first analysis of the occurrence and distribution of NEOs in paired maternal-fetal serum samples.

Neonicotinoids residues in the honey circulating in Chinese market and health risk on honey bees and human

China is the largest beekeeping and honey consumption country globally. Neonicotinoids in honey can pose adverse effects on honey bees and human, but data on neonicotinoids residues in honey and its health risk remain limited in China. A total of 94 honey samples were selected from Chinese market based on production region and sale volume in 2020. Eight neonicotinoids and four metabolites were determined by liquid chromatography coupled to mass spectrometry. Health risk of neonicotinoids in honey on honey bees and human was assessed by hazard quotient (HQ) and hazard index (HI). Neonicotinoids and their metabolites were overall detected in 97.9% of honey samples. Acetamiprid, thiamethoxam, and imidacloprid were top three dominant neonicotinoids in honey with the detection frequencies of 92.6%, 90.4%, and 73.4%, respectively. For honey bees, 78.7% of honey samples had a HI larger than one based on the safety threshold value of sublethal effects. Top three neonicotinoids with the highest percent proportion of HQ larger than one for honey bees were acetamiprid (43.6%), imidacloprid (31.9%), and thiamethoxam (24.5%) and their maximum HQs were 420, 210, and 41, respectively. Based on oral median lethal doses for honey bees, both HQ and HI were lower than one in all honey samples. For human, both HQ and HI were lower than one based on acceptable daily intakes in all honey samples. Neonicotinoids concentrations and detection frequencies in honey samples and its health risk varied with production region, commercial value of nectariferous plants, number of nectariferous plants, and sale price. The results suggested extensive residues of neonicotinoids in honey in Chinese market with a variation by the characteristics of honey. The residues were likely to affect the health of honey bees, but showed no detectable effect on human health.

Residues of neonicotinoid insecticides in surface sediments in lakes and rivers across Jiangsu Province: Impact of regional characteristics and land use types

Neonicotinoid insecticides (NNIs) had been detected in soil and surface water frequently because of extensive use worldwide, however, data regarding regional characteristics and potential influential factors of sediment were scarce. In the present study, eight NNIs were analyzed in 86 surface sediment samples from different regions (central cities, rural areas and suburbs) and land use types (construction land and crop land) in Jiangsu Province. NNIs were widespread in the sediments, with a mean value of 1.73 ± 0.89 ng g^-1 dry weight (dw) (ranged from 0.41 to 3.87 ng g^-1 dw). Imidaclothiz (IMIZ), dinotefuran (DIN) and nitenpyram (NIT) were the dominant compounds in the surface sediment, accounted for half of combined total. The results of regional distribution analysis show that NNIs were at higher concentrations in rural areas and crop land, while the residues of NNIs in lakes were more severe compare with rivers in Jiangsu Province. Region characteristics and land use types have an influence on residues of NNIs in surface sediment. Principal component analysis showed that residues of NNIs in surface sediment in Jiangsu Province mainly originated from protect grain crops (maize), fruit (apples, pears) and vegetables in agricultural systems. The residues of NNIs were found to be mostly concentrated in the northwest and northeast in Jiangsu Province, where were the area of intensive agriculture. To investigate the residues of NNIs, while identify the contributing factors, could provide a scientific basis for basic of region environment management and pollution control.

Domestic Exposure to Chemicals in Household Products, Building Materials, Decoration, and Pesticides: Guidelines for Interventions During the Perinatal Period from the French National College of Midwives

INTRODUCTION

We are exposed to numerous pollutants inside our homes. The perinatal period represents a particular window of vulnerability during which these exposures can have negative health effects over a more or less long term. The objective of this article is to formulate guidelines for health care professionals and intended for parents to reduce exposure to chemical pollutants at home, based on the scientific literature and already existing guidelines.

METHODS

We have followed the methodological procedures set forth by the French authority for health (HAS) to establish guidelines to limit exposure to pollutants in homes. This narrative review of the scientific literature was conducted with two principal objectives: (1) to identify priority substances emitted within homes and that have a reprotoxic potential and (2) to identify measures to limit exposure to these residential pollutants. The guidelines were developed from the data in the literature and from advice already made available by diverse institutions about environmental health during the perinatal period.

RESULTS

Domestic pollutants are numerous and come from both common (that is, shared, eg, painting, cleaning, and maintenance work) and specific (use of household pesticides) sources. Numerous pollutants are suspected or known to produce developmental toxicity, that is, to be toxic to children during developmental stages. Removing some products from the home, protecting the vulnerable (ie, pregnant women and young children) from exposure, and airing the home are among the preventive measures proposed to limit exposure to these chemical substances.

CONCLUSION

Health care professionals can provide advice to parents during the perinatal period to diminish exposure to household pollutants. The lack of interventional studies nonetheless limits the level of evidence for most of these recommendations.

A Pilot Nationwide Survey on the Concentrations of Neonicotinoids and Their Metabolites in Indoor Dust from China: Application for Human Exposure

The present study assessed the residue levels of six parent neonicotinoids (p-NEOs) and four metabolites (m-NEOs) in indoor dust collected from 12 cities of China. Acetamiprid (ACE) and imidacloprid (IMI) were the predominated p-NEOs (detection rates: 98%) with the median values at 4.54 and 7.48 ng/g dry weight (dw), respectively. N-demethyl-acetamiprid (N-dm-ACE) was the most important m-NEO with the median value at 0.69 ng/g dw, while other m-NEOs were rarely detected (detection rates: < 15%). Significant correlation between ACE and thiacloprid (THD) was observed (p < 0.01), indicating their probably concurrent applications. ACE was significantly correlated to N-dm-ACE (p < 0.01), implicating the degradation of ACE in indoor environment. The estimated daily intake (EDI_ing) of NEOs via dust ingestion were far lower than the acceptable daily intake for NEOs. To our knowledge, this study provided a baseline nationwide investigation on the occurrence of NEOs in indoor dust of China.

The Characteristics and Potential Risks of Neonicotinoid Residues in Soils of Different Types of Land Use in Hangzhou

Due to the wide existence of neonicotinoid insecticides (neonics) and their potential impact on ecosystems and human health, they have received special attention in recent years. Soil is not only a sink of neonics but also a source of neonics, so it plays a key role in the ubiquity of neonics in the environment. The purpose of this research was to compare neonics residues in soils of different types of land use and estimate their exposure to different populations via ingestion. A total of 130 soil samples from six different types were collected. The concentrations of seven neonics in soil were simultaneous determined using isotope-dilution ultra-performance liquid chromatography-tandem mass spectrometry. The results showed that at least one neonic was analyzed in all samples. The highest average concentration was 3.42 ng/g (clothianidin), followed by 3.39 ng/g (thiamethoxam), 3.06 ng/g (acetamiprid), 2.84 ng/g (imidacloprid), 2.66 ng/g (nitenpyram), 2.43 ng/g (thiacloprid), and 1.89 ng/g (dinotefuran). IMI and ACE were the most commonly found neonics in soil. The neonic levels in different soils varied significantly. The integrated neonic residue in cropland was much higher than that in other types of land. The risk assessment revealed that the average daily dose (ADD) through ingestion contact with soil was acceptable to children and adults. With the increasing evidence that neonics could cause a variety of toxic effects on mammals and humans, ingestion exposure caused by neonics in soil should also receive continuous attention in future studies.

Determination of Acetamiprid Residues in Vegetables by Indirect Competitive Chemiluminescence Enzyme Immunoassay

Acetamiprid (ACE) is widely used in various vegetables to control pests, resulting in residues and posing a threat to human health. For the rapid detection of ACE residues in vegetables, an indirect competitive chemiluminescence enzyme immunoassay (ic-CLEIA) was established. The optimized experimental parameters were as follows: the concentrations of coating antigen (ACE-BSA) and anti-ACE monoclonal antibody were 0.4 and 0.6 µg/mL, respectively; the pre-incubation time of anti-ACE monoclonal antibody and ACE (sample) solution was 30 min; the dilution ratio of goat anti-mouse-HRP antibody was 1:2500; and the reaction time of chemiluminescence was 20 min. The half-maximum inhibition concentration (IC₅₀), the detection range (IC₁₀–IC₉₀), and the detection limit (LOD, IC₁₀) of the ic-CLEIA were 10.24, 0.70–96.31, and 0.70 ng/mL, respectively. The cross-reactivity rates of four neonicotinoid structural analogues (nitenpyram, thiacloprid, thiamethoxam, and clothianidin) were all less than 10%, showing good specificity. The average recovery rates in Chinese cabbage and cucumber were 82.7–112.2%, with the coefficient of variation (CV) lower than 9.19%, which was highly correlated with the results of high-performance liquid chromatography (HPLC). The established ic-CLEIA has the advantages of simple pretreatment and detection process, good sensitivity and accuracy, and can meet the needs of rapid screening of ACE residues in vegetables.

Carbendazim toxicity in different cell lines and mammalian tissues

The extensive production and use of harmful pesticides in agriculture to improve crop yield has raised concerns about their potential threat to living components of the environment. Pesticides cause serious environmental and health problems both to humans and animals. Carbendazim (CBZ) is a broad spectrum fungicide that is used to control or effectively kill pathogenic microorganisms. CBZ is a significant contaminant found in food, soil and water. It exerts immediate and delayed harmful effects on humans, invertebrates, aquatic animals and soil microbes when used extensively and repeatedly. CBZ is a teratogenic, mutagenic and aneugenic agent that imparts its toxicity by enhancing generation of reactive oxygen species generation. It elevates the oxidation of thiols, proteins and lipids and decreases the activities of antioxidant enzymes. CBZ is cytotoxic causing hematological abnormalities, mitotic spindle deformity, inhibits mitosis and alters cell cycle events which lead to apoptosis. CBZ is known to cause endocrine-disruption, embryo toxicity, infertility, hepatic dysfunction and has been reported to be one of the leading causes of neurodegenerative disorders. CBZ is dangerous to human health, the most common side effects upon chronic exposure are thyroid gland dysfunction and oxidative hepato-nephrotoxicity. In mammals, CBZ has been shown to disrupt the antioxidant defense system. In this review, CBZ-induced toxicity in different cells, tissues and organisms, under in vitro and in vivo conditions, has been systematically discussed.

Comparative study of neonicotinoid insecticides (NNIs) and NNI-Related substances (r-NNIs) in foodstuffs and indoor dust

Comparative studies of neonicotinoid insecticides (NNIs) and NNI-related substances (r-NNIs) in foodstuffs and indoor dust are rare. Herein, we investigated the feature fragmentations of nine NNIs in high-energy collision dissociation cells via high-resolution orbitrap mass spectrometry and observed that NNIs can consistently generate several feature fragments (e.g., C6H5NCl+, C4H3NSCl+, and C6H5NF3+). Consequently, NNIs and r-NNIs were comprehensively (targeted, suspect, and feature fragment-dependent) detected in 107 foodstuff and 49 indoor dust samples collected from Nanjing City (eastern China). We fully or tentatively identified 9 target NNIs and 5 r-NNIs in these samples. NNIs and r-NNIs were detected in 93.5% of the analyzed foodstuff samples, and high concentrations were detected in vegetables (mean: 409 ng/g wet weight [ww]) and fruits (127 ng/g ww). Regarding indoor dust, imidacloprid and acetamiprid exhibited extremely high detection frequencies and contamination levels, and the highest mean concentrations of NNIs and r-NNIs were detected in dormitory samples. Based on the NNI and r-NNI concentrations in the analyzed samples, the mean estimated daily intake values for Chinese adults and children via dietary intake and dust ingestion were 2080-8190 ng/kg bw/day and 378-2680 pg/kg bw/day, respectively.

Profiling of pesticides and pesticide transformation products in Chinese herbal teas

Herbal teas have potential health benefits, but they also contain a variety of pesticides and pesticide transformation products (PTPs) that might brings health risks. Our study maps the pesticides and PTPs in two herbal teas (chrysanthemum and Lusterleaf Holly) from two main producing areas in China. Almost all 122 samples contain pesticides, with concentration ranging from 0.0005 to 10.305 mg/kg. Nearly 40% carbendazim and imidacloprid in chrysanthemum teas and λ-cyhalothrin in Lusterleaf Holly have higher concentration levels than the values permitted in EC Regulation No. 396/2005. Distinct distributions of pesticides were found in different teas and production areas. Eight PTPs were identified along with their parents, and were confirmed using a biosynthetic strategy. Acute, chronic and cumulative health risk assessments of pesticides revealed acceptable results. Our study uncovers the profile of pesticides in herbal teas, and provides new insight into discovering the potential environmental pollution and food contaminants.

Occurrence of azole and strobilurin fungicides in indoor dust from three cities of China

Widespread use of fungicides has raised the concern of exposure to them among the general population. However, there are extremely limited studies reporting the occurrence of fungicides in indoor dust in China. This study aimed to determine ten agricultural fungicides in indoor dust samples collected in three cities of China from 2016 to 2019, assess spatial and seasonal variations, and estimate the related exposure via dust ingestion. Six out of ten fungicides including difenoconazole, prochloraz, tebuconazole, tricyclazole, azoxystrobin, and pyraclostrobin were frequently detected in the dust samples (ranged 65.8-97.7%) and the concentrations of some fungicides showed a strong correlation with each other. Difenoconazole was the most abundant one among the selected fungicides. The highest level of the selected fungicides was observed in the indoor dust collected from Wuhan in summer 2019 (median cumulative concentration of the fungicides: 62.6 ng/g), while the relatively low concentrations of fungicides were found in the dust from Taiyuan (2.08 ng/g). Heavier fungicide contamination was observed in urban districts compared to that in rural districts. Seasonal variations in the fungicide residuals were also identified. The exposure assessment suggested that intake of the selected fungicides via dust ingestion was much lower than dietary intake reported in other studies. This study filled the data gap of fungicide residuals in the indoor dust in China and further studies are needed to identify the sources and determinants of indoor fungicide contamination.

Pesticide Residues in Commonly Consumed Vegetables in Henan Province of China in 2020

Background

Pesticides are widely used in agricultural production to control insect pests and regulate plant growth in China, which may result in the presence of some pesticide residues in the vegetables. However, few studies of monitoring pesticides have been conducted in Henan Province. The aim of this study was to evaluate the level of pesticide residues in commonly consumed vegetables in the regions of Henan Province.

Methods

In this study, we collected 5,576 samples of 15 different vegetables in 17 areas from Henan Province during 2020. Eight kinds of pesticides were analyzed by gas chromatography-mass spectrometry (GC-MS), including procymidone, lambda-cyhalothrin, cypermethrin, pendimethalin, isocarbophos, isazophos, fenthion and deltamethrin. The chi-square test was used to compare the detection rates of pesticide residues in different regions.

Results

Of all the pesticides above, procymidone, lambda-cyhalothrin, cypermethrin, pendimethalin and isocarbophos were detected in vegetables, the detection rates were 27.0%, 16.2%, 11.4%, 3.5%, and 1.9%, respectively. However, isazophos, fenthion, and deltamethrin were not detected. In addition, procymidone, lambda-cyhalothrin, and cypermethrin were detected in urban areas, while pendimethalin was detected in rural areas. The detection rates of cypermethrin and pendimethalin in rural were 19.8% and 5.4%, respectively, which in urban were at relatively lower levels (13.7% and 1.9%, respectively) (P < 0.05). Compared the differences of pesticide detection rates among five areas of Henan province, we found that there were statistical differences in the detection rates of procymidone, cypermethrin and lambda-cyhalothrin in different regions (all P < 0.05).

Conclusion

The results have revealed that the pesticide residues are present. Higher detection rates and more types of pesticides were found in rural areas than urban areas. In addition, there were higher detection rates in Eastern Henan. The findings provided valuable information on the current pesticide residues status, which can be a reference of pesticide supervision and management.

Exposure to neonicotinoid insecticides and their characteristic metabolites: Association with human liver cancer

Neonicotinoid insecticides (NEOs) are commonly applied for pest control in China and around the world. Previous studies reported that NEOs are hepatotoxic to mammals. However, limited studies have explored the associations between NEOs exposure and liver disease. In the present study, we detected six parent NEOs (p-NEOs), including acetamiprid, thiacloprid, dinotefuran, clothianidin, imidacloprid, and thiamethoxam, and five characteristic metabolites (m-NEOs), including 5-hydroxy-imidacloprid, olefin-imidacloprid, N-desmethyl-acetamiprid, 1-methyl-3-(tetrahydro-3-furylmethyl) guanidine and 1-methyl-3-(tetrahydro-3-furyl methyl) urea, in blood samples collected from healthy donors (n = 100; females vs. males: 45 vs. 55; age: 22-91 years) and liver cancer patients (n = 274; females vs. males: 118 vs. 156; age: 11-88 years) in one hospital from Guangzhou city, South China. NEOs were frequently detected (61%-94%) in blood samples, with median concentrations ranging from 0.19 ng/mL to 1.28 ng/mL and 0.20 ng/mL to 2.03 ng/mL for healthy and liver cancer populations, respectively. olefin-imidacloprid was the most abundant NEOs in healthy and liver cancer populations, accounting for 23.4% and 20.7%, respectively. Significant positive correlations among most m-NEOs concentrations were found, and associations between m-NEOs and their corresponding p-NEOs were positively correlated. These findings indicated that the sources of m-NEOs were both endogenous and exogeneous. Females had higher median concentrations of NEOs and their metabolites than males. Moreover, the α-fetoprotein values and blood concentrations of target analytes (r = 0.428-0.601, p < 0.05) were positively correlated. Meanwhile, associations between the concentrations of p-NEOs and m-NEOs and liver cancer were found (odds ratio = 2.33-9.02, 95% confidence interval = 0.31-22.7, p < 0.05), indicating that human exposure to NEOs and their metabolites might increase the odds of liver cancer prevalence. Our work provided a new insight into the hepatotoxicity of NEOs and their metabolites, and human health risks of exposure to these pollutants warranted further studies.

Pesticides in doormat and floor dust from homes close to treated fields: Spatio-temporal variance and determinants of occurrence and concentrations

Indoor dust has been postulated as an important matrix for residential pesticide exposure. However, there is a lack of information on presence, concentrations and determinants of multiple pesticides in dust in residential homes close to treated fields. Our objective was to characterize the spatial and temporal variance of pesticides in house dust, study the use of doormats and floors as proxies for pesticides in indoor dust and identify determinants of occurrence and concentrations. Homes within 250 m from selected bulb fields were invited to participate. Homes within 20 km from these fields but not having agricultural fields within 500 m were selected as controls. House dust was vacuumed in all homes from floors (VFD) and from newly placed clean doormats (DDM). Sampling was done during two periods, when pesticides are used and not-used. For determination of 46 prioritized pesticides, a multi-residue extraction method was used. Most statistical analyses are focused on the 12 and 14 pesticides that were detected in >40% of DDM and VFD samples, respectively. Mixed models were used to evaluate relationships between possible determinants and pesticides occurrence and concentrations in DDM and VFD. 17 pesticides were detected in more than 50% of the homes in both matrixes. Concentrations differed by about a factor five between use and non-use periods among homes within 250 m of fields and between these homes and controls. For 7 pesticides there was a moderate to strong correlation (Spearman rho 0.30-0.75) between concentrations in DDM and VFD. Distance to agricultural fields and air concentrations were among the most relevant predictors for occurrence and levels of a given pesticide in DDM. Concentrations in dust are overall higher during application periods and closer to fields (<250 m) than further away. The omnipresence of pesticides in dust lead to residents being exposed all year round.

Human exposure to neonicotinoids and the associated health risks: A review

Neonicotinoids (NEOs) are a class of broad-spectrum insecticides dominant in the global market. They were distributed extensively in the environment and occurred frequently in humans. Potential health effects of NEOs, such as neurological toxicity and diabetes to non-targeted mammals, have raised concerns. This review summarizes analytical methods of NEOs in human samples, their internal exposure levels and composition profiles in urine, blood, hair, breast milk, saliva and tooth samples with global comparisons, and daily NEOs exposure dose and relative health risks.Urinary NEOs levels in Asian populations were substantially higher than those in the U.S. and Europe, which may be due to different dietary patterns and insecticide applications across regions. N-desmethyl acetamiprid, 5-hydroxy-imidacloprid and olefin-imidacloprid were dominant among detected NEOs. NEO metabolites exhibited higher detection frequencies and levels than their parent compounds in humans, while investigations on NEO metabolites remain much limited. Current exposure assessments mainly focused on short-term urine analysis, while biomaterials for long-term monitoring, such as hair, nail and other alternatives, should also be considered. Large-scale epidemiological studies are critically needed to elucidate potential health outcomes associated with NEOs exposure.

Exposure assessment of neonicotinoid insecticides and their metabolites in Chinese women during pregnancy: A longitudinal study

Neonicotinoid insecticides (NNIs) are the most widely used insecticides globally and ubiquitous in the environment, which has led to widespread human exposure. However, studies on internal exposure levels of NNIs and their metabolites in pregnant women are scarce. In this study, we measured nine parent NNIs and ten main metabolites in 1224 urine samples donated by 408 pregnant women at three trimesters. In the urine samples, the unadjusted vs. specific gravity (SG) adjusted median concentrations and detection frequencies (DFs) of desmethyl-acetamiprid (DM-ACE; 1.01 vs. 1.08 ng/mL; DF: 99.7%), 5-hydroxy-imidacloprid (5-hydroxy-IMI; 0.54 vs. 0.56 ng/mL; 98.5%), imidacloprid-olefin (IMI-olefin; 0.41 vs. 0.44 ng/mL; 99.3%), and desnitro-imidacloprid (DN-IMI; 0.12 vs. 0.12 ng/mL; 90.4%) were higher than their corresponding parent NNIs, acetamiprid (ACE; <0.01 vs. <0.01 ng/mL; 26.4%) and imidacloprid (IMI; 0.04 vs. 0.04 ng/mL; 69.9%). The unadjusted and SG-adjusted median concentrations of clothianidin (CLO), thiamethoxam (THM), and desmethyl-clothianidin (DM-CLO) were 0.05 vs. 0.07, 0.05 vs. 0.06, and 0.04 vs. 0.05 ng/mL, with the DFs of 61.0%, 57.5%, and 75.7%, respectively. The cumulative exposure level, imidacloprid-equivalent total NNIs (IMI_eq), was generated by the relative potency factor approach considering the toxic effects of NNIs and their metabolites. The unadjusted IMI_eq varied from 0.17 ng/mL (SG-adjusted: 0.20) to 1969 ng/mL (SG-adjusted: 1817) with a median of 14.1 ng/mL (SG-adjusted: 14.1). A decreased trend was observed in urinary NNIs and their metabolites throughout the three trimesters. Maternal age, educational level, and household income were related to the concentrations of NNIs and their metabolites. DM-ACE, 5-hydroxy-IMI, and IMI-olefin were significantly lower in winter than in autumn; DN-IMI, THM, CLO, and DM-CLO were significantly higher in both summer and autumn than in winter. The maximum estimated daily intake of IMI_eq [34.8 μg/kg-body weight (bw)/d] was lower than the chronic reference dose of IMI (57 μg/kg-bw/d) currently recommended by the United States Environmental Protection Agency. Human health risk of exposure to NNIs and their main metabolites warranted further studies.

Neonicotinoid insecticide metabolites in seminal plasma: Associations with semen quality

Animal studies have revealed that exposure to neonicotinoid insecticides (NNIs) could compromise male reproductive function; however, related data on the occurrence of NNIs and their specific metabolites in human seminal plasma are scarce. To explore the potential effects of NNI exposure on male semen quality, we determined the concentrations of NNIs and some of their metabolites (collectively defined as mNNIs) in seminal plasma samples collected from men (n = 191) who visited a fertility clinic in Shijiazhuang, North China from 2018 to 2019. Associations between the mNNI concentrations and semen quality parameters were assessed using linear regression models, adjusting for important covariates. In the seminal plasma samples, desmethyl-acetamiprid (DM-ACE, detection frequency: 98.4%), imidacloprid-olefin (IMI-olefin, detection frequency: 86.5%), and desmethyl-clothianidin (DM-CLO, detection frequency: 70.8%) were frequently detected at median concentrations of 0.052, 0.003, and 0.007 ng/mL, respectively; meanwhile other compounds were detected at less than the method detection limits. In the single-mNNI models, the IMI-olefin concentration was associated with decreased progressive motility [IMI-olefin concentration: percent change (%Δ) = -17.0; 95% confidence interval (CI) = -30.3, -0.92; the highest tertile compared with the lowest tertile: %Δ = -21.1; 95% CI = -37.5, -0.23]. Similar results were found in the multiple-mNNIs models. No other inverse associations were found between the other mNNI concentrations and semen quality parameters. This is the first study to identify the occurrence of mNNIs in the seminal plasma and the potential associations of their concentrations with human semen quality parameters. These findings imply an inverse association between the IMI-olefin concentration and semen quality.

Serum concentrations of neonicotinoids and their characteristic metabolites in elderly population from South China: Association with osteoporosis

Neonicotinoids (NEOs) are extensively applied in global agricultural production for pest control but have adverse effects on human health. In this study, the concentrations of six NEOs and three characteristic metabolites were investigated by collecting 200 serum samples from an elderly population in China. Results showed that the NEOs and their metabolites were widely detected (89%-98 %) in the serum samples from the osteoporosis (OP) (n = 120) and non-OP (n = 80) population, and their median concentrations ranged from 0.04 ng/mL to 5.99 ng/mL and 0.01 ng/mL to 2.02 ng/mL, respectively. N-desmethyl-acetamiprid (ACE-dm) was the most abundant NEOs in the serum samples. Gender-related differences were found in concentrations of most NEOs and their metabolites in serum, with males having higher target analytes than females. Significantly (p < 0.05) positive correlations were observed among most NEO concentrations, suggesting that exposure source of these substances is common or related. However, associations between the concentrations of characteristic metabolites and their corresponding NEOs were insignificant, probably because the exogenous intake are the primary sources of metabolites of NEOs instead of the internal biotransformation. The associations between NEO concentrations (i.e., ACE-dm, dinotefuran, and olefin-imidacloprid) and OP (OR = 2.33-6.92, 95 % CI = 0.37-16.9, p-trend < 0.05) indicate that NEO exposure is correlated with increased odds of prevalent OP. This study is the first to document the profiles of NEOs and their metabolites in serum samples collected from an elderly population in South China and examine the relationships between NEO exposure and OP.

Associations of neonicotinoids with insulin and glucose homeostasis parameters in US adults: NHANES 2015-2016

Neonicotinoids are replacement insecticides increasingly used for organophosphates, methylcarbamates, and pyrethroids. Experimental evidence suggests neonicotinoids may affect glucose metabolism and insulin secretion through pancreatic β cell dysfunction, oxidative stress, and inflammation. However, no epidemiologic study has investigated neonicotinoids as potential diabetogens. We examined associations between neonicotinoids with insulin and glucose homeostasis parameters among 1381 non-diabetic adults in the National Health and Nutrition Examination Survey (2015-2016). Urinary concentrations of acetamiprid, clothianidin, imidacloprid, N-desmethyl-acetamiprid, and 5-hydroxy-imidacloprid were quantified. Fasting plasma glucose, insulin, and hemoglobin A_1c (HbA_1c) were assessed. Insulin resistance was defined as a homeostatic model assessment of insulin resistance ≥2.5. We used weighted linear and logistic regression to estimate associations between detectable neonicotinoids with insulin and glucose homeostasis parameters compared to non-detectable neonicotinoid concentrations. Weighted detection frequencies for imidacloprid, 5-hydroxy-imidacloprid, and N-desmethyl-acetamiprid were 4.4 %, 21.5 %, and 32.8 %, respectively. Detectable imidacloprid (β = -4.7 μIU/mL, 95 % confidence interval [CI] -8.5, -0.8) and 5-hydroxy-imidacloprid (β = -2.4 μIU/mL, 95 % CI -4.6, -0.2) were associated with lower fasting plasma insulin levels. Individuals with detectable 5-hydroxy-imidacloprid had lower odds of insulin resistance (odds ratio [OR] = 0.3, 95 % CI 0.2, 0.7). We observed evidence of sexually dimorphic associations between N-desmethyl-acetamiprid with glucose (p_int = 0.079) and 5-hydroxy-imidacloprid with HbA_1c (p_int = 0.038), with patterns suggesting positive associations in males and negative associations in females. Associations between 5-hydroxy-imidacloprid and insulin were modified by body mass index (BMI) (p_int = 0.013). We additionally observed age modified associations between 5-hydyroxy-imidacloprid and glucose (p_int = 0.048). Results suggest neonicotinoids may be associated with insulin and glucose homeostasis indices and call for prospective studies to examine the metabolic impact of these replacement insecticides in humans.

Association between new onset type 1 diabetes and real-world antibiotics and neonicotinoids' exposure-related gut microbiota perturbation

BACKGROUND

The real-world exposure levels of non-therapeutic antibiotics and neonicotinoids in type 1 diabetes (T1D) children and their associations as environmental triggers through gut microbiota shifts remained unknown. We thus investigated the antibiotics and neonicotinoids' exposure levels and their associations with gut microbiota in pediatric T1D.

METHODS

Fifty-one newly onset T1D children along with 67 age-matched healthy controls were recruited. Urine concentrations of 28 antibiotics and 12 neonicotinoids were measured by mass spectrometry. Children were grouped according to the kinds of antibiotics' and neonicotinoids' exposures, respectively. The 16S rRNA of fecal gut microbiota was sequenced, and the correlation with urine antibiotics and neonicotinoids' concentrations was analyzed.

RESULTS

The overall detection rates of antibiotics were 72.5% and 61.2% among T1D and healthy children, whereas the neonicotinoids detection rates were 70.6% and 52.2% (P = 0.044). Children exposed to one kind of antibiotic or two or more kinds of neonicotinoids had higher risk of T1D, with the odd ratios of 2.579 and 3.911. Furthermore, co-exposure to antibiotics and neonicotinoids was associated with T1D, with the odd ratio of 4.924. Antibiotics or neonicotinoids exposure did not affect overall richness and diversity of gut microbiota. However, children who were exposed to neither antibiotics nor neonicotinoids had higher abundance of Lachnospiraceae than children who were exposed to antibiotics and neonicotinoids alone or together.

CONCLUSION

High antibiotics and neonicotinoids exposures were found in T1D children, and they were associated with changes in gut microbiota featured with lower abundance of butyrate-producing genera, which might increase the risk of T1D.

Occurrence and exposure risk assessment of organic micropollutants in indoor dust from Malaysia

Indoor dust is an important source of human exposure to hazardous organic micropollutants (OMPs) because humans spend about 90 % of their time in the indoor environments. This study initially analyzed the concentrations and compositions of OMPs in the dust of different indoor environments from Kuala Lumpur, Malaysia. A total of 57 OMPs were detected and assigned to 7 chemical classes in this study. The total concentration of OMPs ranged from 5980 to 183,000 ng/g, with the median concentration of 46,400 ng/g. Personal care products, organophosphate esters, and pesticides were the dominant groups, with their median concentrations at 12,000, 10,000, and 5940 ng/g, respectively. The concentrations and compositions of influential OMPs varied in different microenvironments, suggesting different sources and usage patterns in the house. Then, the noncarcinogenic and carcinogenic risks of exposure to these substances for diverse age groups were assessed based on the median concentration. Cumulative noncarcinogenic risks of these OMPs via ingestion pathway were estimated to be negligible (1.41 × 10^-4 - 1.87 × 10^-3). The carcinogenic risks of these OMPs were higher than 10^-6 (1.63 × 10^-6 - 6.17 × 10^-6) and should be noted. Theobromine accounted for more than 89 % of the cumulative cancer risk, implying that the carcinogenic risk of theobromine needs further monitoring in the future. Toddler was the most affected group for cancer risk among all the age groups, regardless of the microenvironments. These findings from this study may provide a benchmark for future efforts to ensure the safety of indoor dust for the local residents.

Azole and strobilurin fungicides in source, treated, and tap water from Wuhan, central China: Assessment of human exposure potential

Fungicides are widely used in agriculture worldwide. However, data on the occurrence of fungicides in drinking water are scarce. This study aimed to determine the occurrence of 12 selected fungicides in drinking water, the removal efficiency of conventional water treatment processes for fungicides, and the risk of fungicide exposure. In this study, source water (February and July), treated water (February and July), and tap water samples (February, April, July, and October) were collected from Wuhan, central China, in 2019. Seven of the twelve selected fungicides were 100% detected in the three types of water samples; tricyclazole was found with the highest concentrations in the source water phase (median: 15.2 ng/L; range: 4.21-67.9 ng/L). The concentrations of the 12 selected fungicides remaining in the treated water samples (median proportion of the remaining content: 77.5%) revealed that most of the target analytes may not be removed efficiently by conventional water treatment processes, though they could be removed efficiently by advanced treatment. Higher concentrations of the fungicides were observed in samples collected in July (median: 38.7 ng/L; range: 12.5-85.8 ng/L), followed by those in October (median: 21.8 ng/L; range: 10.2-58.8 ng/L), February (median: 9.82 ng/L; range: 5.63-93.3 ng/L), and April (median: 7.13 ng/L; range: 6.23-91.1 ng/L). The health risk assessment implied that estimated daily intake of these fungicides through tap water ingestion might pose a low risk to consumers, though risk associated with infant exposure to the fungicides requires further attention. This study provides baseline data on the occurrence, removal efficiencies, and seasonal variations of the selected fungicides in tap water from central China.

Urinary metabolites of multiple volatile organic compounds among general population in Wuhan, central China: Inter-day reproducibility, seasonal difference, and their associations with oxidative stress biomarkers

General population are concurrently and extensively exposed to many volatile organic compounds (VOCs), including some Group 1 human carcinogens, such as 1,3-butadiene. However, only a few studies assessed internal exposure levels of VOCs; particularly, very limited studies have examined associations between the urinary concentrations of multiple VOC metabolites (mVOCs) and oxidative stress biomarkers (OSBs) among the general population. In this study, 21 mVOCs and three OSBs including 8-hydroxy-2'-deoxyguanosine (8-OHdG; for DNA), 8-hydroxyguanosine (8-OHG; for RNA), and 4-hydroxy nonenal mercapturic acid (HNEMA; for lipid) were measured in 406 urine samples collected from 128 healthy adults during autumn and winter of 2018 in Wuhan, central China, including repeated samples taken in 3 d from 75 volunteers. Inter-day reproducibility for most mVOCs was good to excellent; urinary concentrations of mVOCs in winter were generally higher than those in autumn. Risk assessment was conducted by calculating hazard quotients for the parent compounds, and the results suggested that acrolein, 1,3-butadiene, and cyanide should be considered as high-priority hazardous ones for management. After false-discovery adjustment, 16 of the studied mVOCs were positively associated with 8-OHdG and 8-OHG (β values ranged from 0.04 to 0.48), and four mVOCs were positively associated with HNEMA (β values ranged from 0.21 to 0.78). Weighted quantile sum regression analyses were used to assess associations of mVOC mixture and OSBs, and we found significantly positive associations between the mixture index and OSBs, among which the strongest mVOC contributors for the associations were 2-methylhippuric acid for both DNA (20%) and RNA (17%) oxidative damage, and trans,trans-muconic acid (50%) for lipid peroxidation. This study firstly reported good to excellent short-term reproducibility, seasonal difference in autumn and winter, and possible health risk in urinary concentrations of multiple mVOCs among the general population.

Contamination of drinking water by neonicotinoid insecticides in China: Human exposure potential through drinking water consumption and percutaneous penetration

Neonicotinoids (NEOs) are the most widely used pesticides and have posed a serious threat to human health. However, data on human exposure to NEOs are extremely scarce. To bridge this gap, human exposure potential of NEOs through drinking water consumption and percutaneous penetration was evaluated with the influences of 17 age groups, 4 seasons, 6 regions, and 2 genders. The results showed that drinking water in the present study had an upper middle level of NEO contamination. Anthropogenic activity and weather condition played important roles in the regional distribution of NEOs in tap water. For both children and adults, NEOs intake from drinking water exposure (NDE) and percutaneous exposure (NPE) in the south regions of China are significantly higher than those in the north regions, while the order of NDE and NPE by season is summer > spring = autumn > winter. Furthermore, human age and gender also have remarkable impacts on NDE and NPE. The age groups of children subjected to the highest NDE and NPE were 9 months - 2 years old and 9-12 years old, respectively. This study provides insights into the role of seasonal and regional influence, age and gender in the risk of drinking water and percutaneous exposure to NEOs.

Effects of imidacloprid on viability and increase of reactive oxygen and nitrogen species in HepG2 cell line

Imidacloprid (IMD) is a neonicotinoid insecticide used in large quantities worldwide in both veterinary and agronomic applications. Several studies have shown adverse effects of IMD on non-target organisms, with the liver being identified as the main affected organ. This study aimed to evaluate the effects of IMD on human hepatoblastoma (HepG2) cells. HepG2 were exposed to IMD (0.25-2.0 mM) for 24 and 48 h. IMD treatment resulted in cytotoxicity in the HepG2, inhibiting cell proliferation in a dose- and time-dependent manner, starting at concentrations of 0.5 mM (24 h) and 0.25 mM (48 h), and reducing cell viability from 0.5 mM onwards (24 and 48 h). IMD significantly decreased the mitochondrial membrane potential at both time points investigated (2.0 mM), and also induced damage to the cell membrane, demonstrated by significant dose and time-dependent increases in lactate dehydrogenase (LDH) release from concentrations of 1.0 mM (24 h) and 0.5 mM (48 h) upwards. IMD treatment also increased the production of reactive oxygen and nitrogen species (ROS/RNS) at rates above 50% following 0.5 mM (24 h) or 0.25 mM (48 h) concentrations, and caused a significant decrease in reduced/oxidized glutathione ratio (GSH/GSSG), indicating oxidative stress. Furthermore, the antioxidant dithiothreitol, which reacts with ROS/RNS and acts as a thiol reducing agent, inhibited the cytotoxic effect of IMD. In addition, the metabolite IMD-olefin was more toxic than IMD. Our results indicate that IMD induces cytotoxicity in HepG2 cells and that this effect may be associated with an increase in the generation of ROS/RNS.

Occurrence, variations, and risk assessment of neonicotinoid insecticides in Harbin section of the Songhua River, northeast China

Neonicotinoid insecticides (NNIs) have been intensively used and exploited, resulting in their presence and accumulation in multiple environmental media. We herein investigated the current levels of eight major NNIs in the Harbin section of the Songhua River in northeast China, providing the first systematic report on NNIs in this region. At least four NNIs in water and three in sediment were detected, with total concentrations ranging from 30.8 to 135 ng L-1 and from 0.61 to 14.7 ng g-1 dw, respectively. Larger spatial variations in surface water NNIs concentrations were observed in tributary than mainstream (p < 0.05) due to the intensive human activities (e.g., horticulture, urban landscaping, and household pet flea control) and the discharge of wastewater from many treatment plants. There was a significant positive correlation (p < 0.05) between the concentrations of residual imidacloprid (IMI), clothianidin (CLO), and Σ4NNIs in the sediment and total organic carbon (TOC). Due to its high solubility and low octanol-water partition coefficient (K ow), the sediment-water exchange behavior shows that NNIs in sediments can re-enter into the water body. Human exposure risk was assessed using the relative potency factor (RPF), which showed that infants have the highest exposure risk (estimated daily intake (ΣIMIeq EDI): 31.9 ng kg-1 bw·d-1). The concentration thresholds of NNIs for aquatic organisms in the Harbin section of the Songhua River were determined using the species sensitivity distribution (SSD) approach, resulting in a value of 355 ng L-1 for acute hazardous concentration for 5% of species (HC5) and 165 ng L-1 for chronic HC5. Aquatic organisms at low trophic levels were more vulnerable to potential harm from NNIs.

Urinary concentrations of acetaminophen in young children in central and south China: Repeated measurements and associations with 8-hydroxy-guanosine and 8-hydroxy-2'-deoxyguanosine

Acetaminophen (AAP) is the most widely used over-the-counter analgesic in the world; it is also a metabolite of industrial chemical aniline. It may predispose individuals to oxidative stress. However, the exposure profile of AAP in the general population in China and the associations between AAP and oxidative stress biomarkers have scarcely been investigated. In this study, we determined the urinary concentrations of AAP and evaluated its associations with 8-hydroxy-guanosine (8-OHG) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), the most widely used biomarkers of nucleoside oxidation affecting RNA and DNA, in 393 urine samples collected from 131 healthy children (0-6.6 y) on three consecutive days from Wuhan, central China, and Shenzhen, south China. AAP was found in all urine samples, suggesting that exposure to AAP was ubiquitous in young children in central and south China. The median concentration of specific gravity (SG)-adjusted AAP was 9.21 ng/mL (range: 1.11-1 453 ng/mL). Good inter-day reproducibility was observed for SG-adjusted AAP concentrations (intraclass correlation coefficient, 0.75). The SG-adjusted urinary 8-OHdG and 8-OHG concentrations were positively correlated with AAP (β = 0.08; 95% confidence interval [95% CI]: 0.02-0.13, and β = 0.10; 95% CI: 0.04-0.15, respectively). The data indicated that AAP exposure might be associated with oxidative DNA and RNA damage in the general population with unintentional exposure. To our knowledge, this is the first report of AAP exposure in young healthy children in central and south China. This is also the first study to evaluate the inter-day variations in urinary AAP concentrations and to explore the associations between AAP exposure and oxidative stress biomarkers in the general population.