ATR induces hepatic lipid metabolism disorder in rats by activating IRE1α/XBP1 signaling pathway

Atrazine (ATR) is a widely used herbicide and due to its persistence in environment and bioaccumulation, it can cause harmful impacts on human health. ATR exposure can lead to disorders of lipid metabolism in the liver, but its underlying mechanism is still unclear. 40 eight-week-old rats were given different doses of ATR (0, 0.5, 5 and 50 mg/kg/d) for 90 days. The liver tissue and serum were collected for histological observation and biochemical analysis. The levels of lipid and oxidative stress were assessed using colorimetry. Changes in MMP and ROS of liver cells were observed through flow cytometry. The expression of mRNA and protein was detected using Real-Time PCR and western blot. The results showed that TC and HDL-C levels in both the liver and serum were increased in the ATR-treated groups. The levels of MDA were accumulated, while the levels of SOD and GSH were depleted in the liver with ATR exposure. The expression of liver lipid metabolism related genes (SCD1, DGAT2, ACC1, PPARγ) was elevated. The liver ERS was activated and the gene expression of IRE1α/XBP1 signal pathway and GRP78, GRP94 in the liver was increased. There was a correlation between the levels of ERS and the levels of lipid metabolism. These results suggested that ATR can activate ERS and promote the expression of IRE1α/XBP1 signaling pathway, and further lead to lipid metabolism disorders in rat liver. This study can provide valuable insights as a reference for the prevention and control of hazards associated with agricultural residues.

Selectivity of herbicides used in corn on Crotalaria ochroleuca G. Don

In the cropping systems that integrate the corn crop, the insertion of Crotalaria ochroleuca G. Don is predominantly intercropped. In this context, there is a need to observe herbicides that present selectivity for this sunn hemp species. The objective of this study was to evaluate the selectivity of pre and post-emergent herbicides on C. ochroleuca. Two field experiments were conducted in randomized blocks with four replications, involving the pre-emergence and post-emergence application of different herbicide treatments. For the pre-emergent ones, amicarbazone, atrazine and flumioxazin provided phytotoxicity higher than 90% and, consequently, low plant biomass. On the other hand, acetochlor and s-metolachlor did not cause phytotoxicity and did not affect the dry mass of crotalaria. In post-emergence, atrazine + mesotrione showed phytotoxicity >95%, followed by nicosulfuron and 2.4-D with phytotoxicity between 50-60%, whereas tembotrione did not cause injury to the plants. Thus, it was found that among the pre-emergent, acetochlor and s-metolachlor were selective, and for the emerging powders, only tembotrione was the most selective for all parameters analyzed.

Monitoring the temporal changes in herbicide-resistant Amaranthus tuberculatus: a landscape-scale probability-based estimation in Iowa

BACKGROUND

A landscape-scale probability-based sampling of Iowa soybean [Glycine max (L.) Merr.] fields was conducted in 2013 and 2019; Amaranthus tuberculatus [Moq.] J.D. Sauer seed was collected from 97 random geospatial selected fields. The objectives were to evaluate the prevalence and distribution of herbicide-resistant A. tuberculatus (waterhemp) in soybean fields and evaluate temporal changes over 6 years. Amaranthus tuberculatus seedlings were evaluated for resistance to imazethapyr, atrazine, glyphosate, lactofen and mesotrione at 1× and 4× label rates.

RESULTS

Resistance to imazethapyr, glyphosate, lactofen and mesotrione at the 1× rate increased significantly from 2013 to 2019 and was found in 99%, 97%, 16% and 15% of Iowa A. tuberculatus populations in 2019, respectively. Resistance to atrazine at the 4× rate increased over time; atrazine resistance was found in 68% of populations in 2019. Three-way multiple herbicide-resistant A. tuberculatus was the most frequent and increased significantly to 4× rates from 16% in 2013 to 43% of populations in 2019. All A. tuberculatus populations resistant to HPPD-inhibitor herbicides also were resistant to atrazine.

CONCLUSION

To the best of our knowledge, this is the first probability-based study that presented evolution of A. tuberculatus herbicide resistance over time. The results demonstrated that imazethapyr, atrazine and glyphosate resistance in Iowa A. tuberculatus populations was frequent whereas resistance to lactofen and mesotrione was less frequent. Most Iowa A. tuberculatus populations evolved resistance to multiple sites of action over time. The results of our study are widely applicable given the similarities in weed management practices throughout the Midwest United States. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Differential interference of copper with endophytic bacterial inoculation: Atrazine decontamination in Acorus tatarinowii and culture solution

To clarify the interference effects of inorganic ions, Acorus tatarinowii and endophytic bacterium Herbaspirillum huttiense (Hh) were combined to decontaminate atrazine pollution under different copper levels. This study verified inoculation effects and revealed the complicated processes of atrazine transformation in solutions. 35.9% leaf biomass was promoted by Hh inoculation, and the value was lowered to 7.87% by high doses of copper. The changing trend of leaf N, K, and S contents, and tiller numbers were consistent with that of leaf biomass. Hh injection improved atrazine accumulation by 43.5% in roots, and under copper interference, this value lowered to 10.6%. Hh promoted atrazine deethylation in plants, which was copper-dose dependent in different plant organs. In solutions, atrazine was conjugated with small-molecule secretions at m/z 118, detoxicated into 2-hxydroatrazine and 2-hydroxy-4-acetamido-atrazine, then the triazine ring opened. Copper interference had a more significant impact on residual atrazine conversion products than Hh inoculation treatments. Hh treatment promoted the ring-opening degradation of atrazine in water. The addition of high doses of copper ions promoted the oxidative process of atrazine while inhibiting its ring-opening transformation process in water.

Exposure to three herbicide mixtures influenced maize root-associated microbial community structure, function and the network complexity

Herbicide mixtures are a new and effective agricultural strategy for managing suppress weed resistance and have been widely used in controlling weeding growth in maize fields. However, the potential ecotoxicological impact of these mixtures on the microbial community structure and function within various root-associated niches, remains inadequately understood. Here, the effects of nicosulfuron, mesotrione and atrazine on soil enzyme activity and microbial community structure and function were investigated when applied alone and in combination. The findings indicated that herbicide mixtures exhibit a prolonged half-life compared to single herbicides. Ecological niches are the major factor influencing the structure and functions of the microbial community, with the rhizosphere exhibiting a more intensive response to herbicide stress. Herbicides significantly inhibited the activities of soil functional enzymes, including dehydrogenase, urease and sucrose in the short-term. Single herbicide did not drastically influence the alpha or beta diversity of the soil bacterial community, but herbicide mixtures significantly increased the richness of the fungal community. Meanwhile, the key functional microbial populations, such as Pseudomonas and Enterobacteriaceae, were significantly altered by herbicide stress. Both individual and combined use of the three herbicides reduced the complexity and stability of the bacterial network but increased the interspecific cooperations of fungal community in the rhizosphere. Moreover, by quantification of residual herbicide concentrations in the soil, we showed that the degradation period of the herbicide mixture was longer than that of single herbicides. Herbicide mixtures increased the contents of NO3--N and NH4+-N in the soil in the short-term. Overall, our study provided a comprehensive insight into the response of maize root-associated microbial communities to herbicide mixtures and facilitated the assessment of the ecological risks posed by herbicide mixtures to the agricultural environment from an agricultural sustainability perspective.

Glucose oxidase-like Co-MOF nanozyme-catalyzed self-powered sensor for sensitive detection of trace atrazine in complex environments

The self-powered sensor (SPS) is a sensor method that does not require the external power source and has the potential for portable detection of environmental contaminants. In this work, for the first time, a biomolecule-free SPS for detection of ultra-trace triazine endocrine disruptor atrazine (ATZ) with high sensitivity and selectivity is constructed using a glucose oxidase (GOD)-like cobalt metal-organic framework (Co-MOF) nanozyme-modified high-performance anode and a molecularly imprinted cathode. By modulating the size and morphology of the prepared materials, Co-MOF nanozyme with superior GOD-like property (Michaelis constant Km = 15.8 mM) has been obtained and modified at the anode to catalyze glucose oxidation with high efficiency and provide energy continuously and stably for the SPS. The separation mode of anodic energy supply-cathodic recognition ensures the recognition effect without affecting the catalytic characteristic of Co-MOF and the output signal of the SPS. The designed SPS has a wide linear range of 1 pM-100 nM and a detection limit as low as 0.65 pM, as well as superior selectivity and good stability. The present work provides a promising approach for the design of self-powered sensors which can be extended to detection of a wider range of environmental pollutants.

Polar electric field-modulated peroxymonosulfate selective activation for removal of organic contaminants via non-radical electron transfer process

Nonradical electron transfer process (ETP) in peroxomonosulfate (PMS) based advanced oxidation processes (AOPs) is regarded promising for selective degradation of organic contaminants in water, however, the subjective modulation strategy and the definitive mechanistic elucidation of ETP are still lacking. Herein, we proposed a heretofore unreported yet efficient ETP indution approach by construction of polar electrical field on biochar via nonmetallic elements co-doping. Physicochemical characterizations and density functional theory (DFT) calculations verified the electronegativity difference among boron, nitrogen, and sulfur elements bestowed robust local electric fields on biochar surface (BC-BNS), which effectively enhanced the adsorption complexation and charge transfer between biochar and PMS. Compared to the other single-doped or co-doped biochar, BC-BNS exhibited superior catalytic performance of PMS activation for degradation of atrazine (ATZ) (kobs=0.036 min-1), as well as various kinds of electron-rich organics. The remarkable catalytic degradation capacity was further verified in various aqueous matrices and background factors, representing the excellent selectivity. Analysis of contribution from reactive oxygen species and electrochemical testing together substantiated the role of polar electric fields in facilitating the modulation from singlet oxygen (1O2) to ETP as a prevailing mechanism. DFT calculations and apparent interactions revealed the dissociation of S-O bond was thermodynamically favored within this potent localized electric field, which further induced the cleavage of OO bond and ultimately promoted the dual electron transfer between ATZ and PMS. The superiority of BC-BNS/PMS system was further validated with the low ecotoxicity caused by enhanced dechlorination, the low energy consumption, and the long-term effectiveness. The novel modulation principle and atomic-level mechanism exploration gave suggestions for advancing ETP-dominated AOP to remove recalcitrant contaminants during water treatment and restoration.

Terminal Residue and Dietary Risk Assessment of Atrazine and Isoxaflutole in Corn Using High-Performance Liquid Chromatography-Tandem Mass Spectrometry

Isoxaflutole and atrazine are representative pesticides for weed control in corn fields. Formulations containing these two pesticides have been registered in China, and their residues may threaten food safety and human health. In this study, a method for simultaneous determination of isoxaflutole, atrazine, and their metabolites in fresh corn, corn kernels, and corn straw was established based on modified QuEChERS pre-treatment and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The linearity of seven compounds was good (R2 ≥ 0.9912), and the matrix effect was 48.5-77.1%. At four spiked levels of 0.01, 0.02, 0.05, and 0.5 mg kg-1, all compounds' average recovery was 76% to 116%, with relative standard deviation (RSD) less than 18.9%. Field experiments were conducted in Liaoning, Heilongjiang, Inner Mongolia, Shanxi, Beijing, and Yunnan provinces to study the terminal residues. The terminal residues of all compounds were below the LOQ (0.01 mg kg-1) in fresh corn and corn kernels, and atrazine residues in corn straw ranged from <0.05 mg kg-1 to 0.17 mg kg-1. Finally, a dietary risk assessment was conducted based on residues from field trials, food consumption, and acceptable daily intake (ADI). For all populations, the chronic dietary risk probability (RQc) of atrazine was between 0.0185% and 0.0739%, while that of isoxaflutole was 0.0074-0.0296%, much lower than 100%. The results may provide scientific guidance for using isoxaflutole and atrazine in corn field ecosystems.

Integrating environmental carry capacity based on pesticide risk assessment in soil management: A case study for China

Pesticides are widely used in agriculture and can pose risks to soil health and environmental quality. This study assessed the occurrence, distribution, ecological risk, and environmental carrying capacity of 56 currently used pesticides and three metabolites in agricultural soils of Horqin Left Middle Banner, a typical Northeast China agricultural area. 29 pesticides were detected, with atrazine, clothianidin, and propiconazole the most common. Clothianidin and difenoconazole were high-risk to non-target organisms according to risk-toxicity exposure ratio and risk quotient approaches. This study provides a comprehensive and improvement framework for pesticide soil environmental carrying capacity (SECC) assessment and soil quality protection early warning. The SECC model showed no pesticides surpassed the soil carrying capacity threshold under the current application pattern. Five pesticides (clothianidin, difenoconazole, propiconazole, atrazine, and imidacloprid) may reach the threshold within 10 years, requiring pesticide reduction and soil quality monitoring. An early warning system based on SECC values and cumulative amounts of pesticides predicted that clothianidin may exceed the threshold within 0.1 years. These pesticides should be prioritized for management and regulation to prevent soil environmental degradation. The findings can help inform policymakers and stakeholders on pesticide management and sustainable agricultural development in Horqin Left Middle Banner and similar regions.

Degradation of co-applied Atrazine and Fipronil in Phanerochaete Chrysosporium Augmented Biobeds

White rot fungi possess an enzymatic system that is non-specific to any pesticide and can be used for pesticide detoxification in biobeds. The present study evaluated potential of Phanerochaete chrysosporium to degrade co-applied atrazine and fipronil in ash or biochar biomixtures. Five biomixtures were prepared by partially replacing compost in rice straw-compost biomixture (BM) with 10% rice husk ash (RHA), 10% sugarcane bagasse ash (SBA), and 1 and 5% wheat straw biochar (WBC). Results suggested that after 30 days P. chrysosporium augmented biobeds resulted in 60.52-72.72% atrazine and 69.57-72.52% fipronil degradation. Hydroxyatrazine and fipronil sulfone were detected as the only metabolite of atrazine and fipronil, respectively, and were further degraded. Although, SBA significantly enhanced atrazine degradation, RHA or SBA had no significant effect on fipronil degradation. WBC (5%) slowed down degradation of both pesticides.

Responses to herbicides of Arctic and temperate microalgae grown under different light intensities

In aquatic ecosystems, microalgae are exposed to light fluctuations at different frequencies due to daily and seasonal changes. Although concentrations of herbicides are lower in Arctic than in temperate regions, atrazine and simazine, are increasingly found in northern aquatic systems because of long-distance aerial dispersal of widespread applications in the south and antifouling biocides used on ships. The toxic effects of atrazine on temperate microalgae are well documented, but very little is known about their effects on Arctic marine microalgae in relation to their temperate counterparts after light adaptation to variable light intensities. We therefore investigated the impacts of atrazine and simazine on photosynthetic activity, PSII energy fluxes, pigment content, photoprotective ability (NPQ), and reactive oxygen species (ROS) content under three light intensities. The goal was to better understand differences in physiological responses to light fluctuations between Arctic and temperate microalgae and to determine how these different characteristics affect their responses to herbicides. The Arctic diatom Chaetoceros showed stronger light adaptation capacity than the Arctic green algae Micromonas. Atrazine and simazine inhibited the growth and photosynthetic electron transport, affected the pigment content, and disturbed the energy balance between light absorption and utilization. As a result, during high light adaptation and in the presence of herbicides, photoprotective pigments were synthesized and NPQ was highly activated. Nevertheless, these protective responses were insufficient to prevent oxidative damage caused by herbicides in both species from both regions, but at different extent depending on the species. Our study demonstrates that light is important in regulating herbicide toxicity in both Arctic and temperate microalgal strains. Moreover, eco-physiological differences in light responses are likely to support changes in the algal community, especially as the Arctic ocean becomes more polluted and bright with continued human impacts.

Model-Based Analysis of Lactuca sativa Root Growth under the Action of Herbicides in Milli-Channel Arrays with In Situ Imaging

Extracting practical information from the large amounts of data gathered during the live imaging analysis of plant organs is a challenging issue. The present work investigates the use of the logistic growth model to analyze experimental data from root elongation assays performed in milli-fluidic devices with in situ imaging. Lactuca sativa was used as a bioindicator and was subjected to wide concentration ranges of four different herbicides: 2,4-D, atrazine, glyphosate, and paraquat. The model parameters were directly connected to standard indicators of toxicity and plant development, such as the LD50 and the absolute growth rate, respectively. In addition, it was found that realistic predictions of the maximum root length can be achieved about 60 h before the bioassay end point, which could significantly shorten the turnaround time. The combination of milli-fluidic devices, real-time imaging, and model-based data analysis becomes a powerful tool for environmental studies and ecotoxicity testing.

The role of reactive phosphate species in the abatement of micropollutants by activated peroxymonosulfate in the treatment of phosphate-rich wastewater

This study investigated the mechanisms of forming reactive species to degrade micropollutants through the activation of peroxymonosulfate (PMS) by phosphate, a prevalent ion in wastewater. Considering the density functional theory results, the formation of hydrogen bonds between phosphate and PMS molecules might be the crucial step in the overall reactions, which prefers producing ⋅OH and reactive phosphate species (RPS, namely H2PO4⋅, HPO4⋅-, and PO4⋅2-) to yielding SO4⋅-. Besides, in the phosphate (5 mM)/PMS system at pH = 8, HPO4⋅- was modeled to be the dominant radical with a steady-state concentration of 3.6 × 10-12 M, which was 666 and 773 times higher than those of ⋅OH and SO4⋅-. The contributions of 1O2, ⋅OH, SO4⋅-, and RPS to the micropollutant decomposition in phosphate/PMS were studied, and RPS were found to be selective for micropollutants with electron-donating moieties (such as phenolic and aniline groups). Additionally, the degradation pathways of bisphenol A, diclofenac, ibuprofen, and atrazine in phosphate/PMS were proposed according to the detected transformation products. Cytotoxicity analysis was carried out to evaluate the potential environmental impacts resulting from the degradation of micropollutants by phosphate/PMS. This study confirmed the significance of RPS for micropollutant degradation during PMS-based treatment in phosphate-rich scenarios.

Contaminant occurrence, water quality criteria and tiered ecological risk assessment in water: A case study of antifouling biocides in the Qiantang River and its estuary, Eastern China

Antifouling biocides may cause adverse effects on non-target species. This study aims to determine the distribution, sources, and ecological risks of antifouling biocides in the surface waters of the Qiantang River and its estuary in eastern China. The concentrations of total antifouling biocides were ranged from 12.9 to 215 ng/L for all water samples. Atrazine, diuron and tributyltin were the major compounds in the water bodies of the study area. The acute and chronic toxicity criteria for tributyltin, diuron and atrazine were derived for freshwater and saltwater, respectively, based on the species sensitivity distribution approach. The freshwater and saltwater criteria were slightly different, and the toxicity to aquatic organisms could be summarized as tributyltin > diuron > atrazine. The graded ecological risk rating showed that the long-term risk of TBT was significant in coastal waters. The pollution of TBT in the Qiantang River deserves further attention.

Adsorption-desorption characteristics of atrazine on soil and vermicompost prepared with different ratios of raw materials

In this work, vermicompost was prepared with maize stover and cattle dung in ratios of 60:40 (VC1), 50:50 (VC2) and 40:60 (VC3), and the physicochemical properties of the vermicompost were related to the ratio of the raw materials used. The effect of the vermicomposts on the adsorption kinetics, adsorption isotherms and desorption of atrazine were investigated in unamended soil (S) and soil amended with 4% (w/w) of VC1(S-VC1), VC2(S-VC2) and VC3(S-VC3). The total organic carbon (TOC) content of VC1, VC2 and VC3 was 38.46, 37.33 and 34.47%, the HA content was 43.50, 42.22 and 39.28 g/kg, and the HA/FA ratios was 1.47, 0.44 and 0.83, respectively. The adsorption of atrazine on the soil, on the vermicompost and on soils amended with vermicompost followed a pseudo-second-order kinetic model. The Freundlich equation better fitted the adsorption isotherm of atrazine. The vermicomposts enhanced atrazine adsorption and decreased atrazine desorption. Correlation analysis showed that the TOC and HA were significantly positively correlated with Kf, which indicated that TOC and HA of the vermicomposts contributed significantly to the adsorption and desorption of atrazine. This study demonstrated that vermicomposts have great potential in the bioremediation of atrazine pollution and that their role is related to the raw materials used to prepare them.

Predicting the relationship between pesticide genotoxicity and breast cancer risk in South Indian women in in vitro and in vivo experiments

Breast cancer is the third most common cancer in women after skin and lung cancer. Pesticides are of interest in etiologic studies of breast cancer because many pesticides mimic estrogen, a known breast cancer risk factor. In this study, we discerned the toxic role of the pesticides atrazine, dichlorvos, and endosulfan in inducing breast cancer. Various experimental studies, such as biochemical profiling of pesticide-exposed blood samples, comet assays, karyotyping analysis, pesticide and DNA interaction analysis by molecular docking, DNA cleavage, and cell viability assays, have been carried out. Biochemical profiling showed an increased level of blood sugar, WBC, hemoglobin, and blood urea in the patient exposed to pesticides for more than 15 years. The comet assay for DNA damage performed on patients exposed to pesticides and pesticide-treated blood samples revealed more DNA damage at the 50 ng concentration of all three pesticides. Karyotyping analysis showed enlargements in the heterochromatin region and 14pstk+, and 15pstk+in the exposed groups. In molecular docking analysis, atrazine had the highest glide score (- 5.936) and glide energy (- 28.690), which reveals relatively high binding capability with the DNA duplex. The DNA cleavage activity results showed that atrazine caused higher DNA cleavage than the other two pesticides. Cell viability was the lowest at 50 ng/ml (72 h). Statistical analysis performed using SPSS software unveiled a positive correlation (< 0.05) between pesticide exposure and breast cancer. Our findings support attempts to minimize pesticide exposure.

Emerging organic contaminants in the River Ganga and key tributaries in the middle Gangetic Plain, India: Characterization, distribution & controls

The presence and distribution of emerging organic contaminants (EOCs) in freshwater environments is a key issue in India and globally, particularly due to ecotoxicological and potential antimicrobial resistance concerns. Here we have investigated the composition and spatial distribution of EOCs in surface water along a ∼500 km segment of the iconic River Ganges (Ganga) and key tributaries in the middle Gangetic Plain of Northern India. Using a broad screening approach, in 11 surface water samples, we identified 51 EOCs, comprising of pharmaceuticals, agrochemicals, lifestyle and industrial chemicals. Whilst the majority of EOCs detected were a mixture of pharmaceuticals and agrochemicals, lifestyle chemicals (and particularly sucralose) occurred at the highest concentrations. Ten of the EOCs detected are priority compounds (e.g. sulfamethoxazole, diuron, atrazine, chlorpyrifos, perfluorooctane sulfonate (PFOS), perfluorobutane sulfonate, thiamethoxam, imidacloprid, clothianidin and diclofenac). In almost 50% of water samples, sulfamethoxazole concentrations exceeded predicted no-effect concentrations (PNECs) for ecological toxicity. A significant downstream reduction in EOCs was observed along the River Ganga between Varanasi (Uttar Pradesh) and Begusarai (Bihar), likely reflecting dilution effects associated with three major tributaries, all with considerably lower EOC concentrations than the main Ganga channel. Sorption and/or redox controls were observed for some compounds (e.g. clopidol), as well as a relatively high degree of mixing of EOCs within the river. We discuss the environmental relevance of the persistence of several parent compounds (notably atrazine, carbamazepine, metribuzin and fipronil) and associated transformation products. Associations between EOCs and other hydrochemical parameters including excitation emission matrix (EEM) fluorescence indicated positive, significant, and compound-specific correlations between EOCs and tryptophan-, fulvic- and humic-like fluorescence. This study expands the baseline characterization of EOCs in Indian surface water and contributes to an improved understanding of the potential sources and controls on EOC distribution in the River Ganga and other large river systems.

Adsorptive behavior of multi-walled carbon nanotubes immobilized magnetic nanoparticles for removing selected pesticides from aqueous matrices

The present work synthesized two new materials of functionalized multi-walled carbon nanotubes (MWCNT-OH and MWCNT-COOH) impregnated with magnetite (Fe₃O₄) using solution precipitation methodology. The resulting MWCNT-OH-Mag and MWCNT-COOH-Mag materials were characterized by scanning electron microscopy coupled with energy dispersion X-ray spectroscopy, Fourier transform infrared, X-ray diffraction, atomic force microscopy, and electrical force microscopy. The characterization results indicate that the -OH functional groups in the MWCNT interact effectively with magnetite iron favoring impregnation and indicating the regular distribution of nanoparticles on the surface of the synthesized materials. The adsorption efficiency of the MWCNT-OH-Mag and MWCNT-COOH-Mag materials was tested using the pollutants 2,4-D and Atrazine. Over batch studies carried out under different pH ranges, it was found that the optimal condition for 2,4-D adsorption was at pH 2, while for Atrazine, it was found at pH 6. The rapid adsorption kinetics of 2,4-D and Atrazine reaches equilibrium within 30 min. The pseudo-first-order model described 2,4-D adsorption well. The General-order model described better atrazine adsorption. The magnetically doped adsorbent functionalized with -OH surface groups (MWCNT-OH-Mag) demonstrated superior adsorption performance and increased Fe-doped sites. The Sips model described the adsorption isotherms accurately. MWCNT-OH-Mag presented the greatest adsorption capacity at 51.4 and 47.7 mg g^-1 for 2,4-D and Atrazine, respectively. Besides, electrostatic forces and complexation rule the molecular interactions between metals and pesticides. The leaching and regeneration tests of the synthesized materials indicate high stability in an aqueous solution. Furthermore, experiments with wastewater samples contaminated with the model pollutants indicate that the novel adsorbents are highly promising for enhancing water purification by adsorptive separation.

Safety profile evaluation of different herbicides used on peach rootstock seedlings

To screen out suitable herbicides for peach nurseries, we treated the potted seedlings of the peach rootstock 'Nemaguard' with eleven herbicides under recommended doses to investigate the changes of physiological indices and comprehensively evaluate the safety of different herbicides using principal component analysis (PCA). The results showed that soil application of quizalofop-p exhibited no detectable phytotoxicity on rootstock seedlings, while the remaining herbicides generated multiple symptoms, including green loss, wilting, spot, and withering. Starane caused rapid wilting and death, with a 100.0% phytotoxicity index (PI). Soil application of n-(phosphonomethyl)glycine, glufosinate-ammonium, acetochlor, and MCPA-Na showed a PI＞65.0%. As compared with the control, all herbicides inhibited leaf area growth to varying degrees, with a 10.0%-56.2% and 5.8%-44.4% reduction in young leaf area and mature leaf area, respectively. All herbicides, except quizalofop-p, increased the electrolyte permeability of leaf and root tip cells by 21.2%-145.0% and 36.9%-291.4%, respectively, and significantly inhibited root growth. The total root length, root surface area, root volume, and the number of root tips significantly decreased by 37.3%-75.3%, 35.7%-83.0%, 44.3%-89.9%, and 42.6%-73.7%, respectively. Although net photosynthetic rate (Pn) and transpiration rate (Tr) of leaves were not significantly affected by quizalofop-p, mesotrione-atrazine, MCPA-Na·bentazone, bensulfuron-methyl·quinclorac, and bensulfuron-methyl·acetochlor, there was significant reduction of 29.6%, 28.9%, 28.4% and 27.9% in Pn and 21.9%, 29.2%, 26.4%, and 19.7% in Tr post soil application of n-(phosphonomethyl)glycine, glufosinate-ammonium, acetochlor, and MCPA-Na. The overall safety ranking of the 11 examined herbicides is as follows: quizalofop-p>bensulfuron-methyl·acetochlor>bensulfuron-methyl·quinclorac>esotrione·atrazine> auizalofop-p·fluoroglycofen>acetochlor>MCPA-Na·bentazone>MCPA-Na>n-(phosphonomethyl)glycine>glufosinate-ammonium>sterane.

Sensibility, multiple tolerance and degradation capacity of forest species to sequential contamination of herbicides in groundwaters

Herbicides have already reported environmental contamination in several countries with intense agricultural activity. The transport of these molecules due to leaching and surface runoff has frequently caused contamination of rivers, groundwater and soil in non-agricultural areas. Thereby, we propose to investigate the sensitivity and phytoremediation capacity of 5 native Cerrado species to sequential exposure to 2,4-D, atrazine, diuron and hexazinone. We hypothesized that species have different sensitivity levels to sequential exposure to these herbicides absorbed from contaminated simulated groundwater model. The objectives of this work were: i) to determine the sensitivity of native cerrado species by sequential exposure to 2,4-D, atrazine, diuron and hexazinone via contaminated simulated groundwater model; ii) to evaluate the presence and degradation capacity of these herbicides in the soil and water leached by tolerant species. Some species showed high phytoremediation potential for groundwater already contaminated with 2,4-D, atrazine, diuron and hexazinone. S. macranthera and C. antiphilitica are tolerant and reduce the concentration of herbicides in simulated groundwater model. Among these species, C. antiphilitica reduces the concentration of all herbicides, suggesting greater adaptability to compose decontamination strategies in areas close to agricultural systems that use 2,4-D herbicides, atrazine, diuron and hexazinone. Also, our results show that herbicides can act as a selection factor for Cerrado forest species, however, two species can mitigate the effects of contamination due to their ability to degrade herbicides.

Efficient degradation of atrazine through in-situ anchoring NiCo2O4 nanosheets on biochar to activate sulfite under neutral condition

Sulfite (S(IV)) is a promising substitute for sulfate radical-based advanced oxidation processes. Here, a composite of in-situ anchoring NiCo₂O₄ nanosheets on biochar (BC) was firstly employed as a heterogeneous activator for sulfite (NiCo₂O₄@BC-sulfite) to degrade atrazine (ATZ) in the neutral environment. The synergistic coupling of BC and NiCo₂O₄ endows the resulting composite excellent catalytic activity. 82% of the degradation ratio of ATZ (1 mg/L) could be achieved within 10 min at initial concentrations of 0.6 g/L NiCo₂O₄@BC, 3.0 mmol/L sulfite in neutral environment. When further supplementing sulfite into the system at 20 min (considering the depletion of sulfite), outstanding degradation efficiency (∼ 100%) were achieved in the next 10 min without any other energy input by the NiCo₂O₄@BC-sulfite system. The features of the prepared catalysts and the effects of some key parameters on ATZ degradation were systematically examined. A strong inner-sphere complexation (Co²⁺/Ni²⁺-SO₃^2-) was explored between sulfite and the metal sites on the NiCo₂O₄@BC surface. The redox cycle of the surface metal efficiently mediated sulfite activation and triggered the series radical chain reactions. The generated radicals, in particular the surface-bound radicals were involved in ATZ degradation. High performance liquid chromatography-tandem mass spectrometry (LC-MS) technique was used to detect the degradation intermediates. Density functional theory (DFT) calculations were performed to illustrate the possible degradation pathways of ATZ. Finally, an underlying mechanism for ATZ removal was proposed. The present study offered a low-cost and sustainable catalyst for sulfite activation to remove ATZ in an environmentally friendly manner from wastewater.

Stimulation of atrazine degradation by activated carbon and cathodic effect in soil microbial fuel cell

Soil microbial fuel cells (MFCs) have been increasingly studied in recent years and have attracted significant attention as an environmentally sustainable bioelectrochemical technology. However, the poor conductivity of the soil matrix and the neglect of the cathodic function have limited its application. In this study, quartz sand and activated carbon were subjected to investigation on their influence on atrazine degradation. Atrazine was introduced in different layers (cathode, upper layer) to explore the cathodic effect on atrazine removal. The results revealed that activated carbon could reduce the internal resistance (693 Ω) and generate the highest power density (25.51 mW/m²) of the soil MFCs, and thus increase the removal efficiency (97.92%) of atrazine. The dynamic degradation profiles of atrazine were different for different adding layers. The cathode electrode acted as an electron donor could increase the distance of the effective influence of the soil MFCs' cathode from the middle to the cathode layer. The cathode (region) and the region close to the cathode could degrade atrazine with the atrazine removal efficiencies ranging from 60.67% to 92.79%, and the degradation ability of the cathode was stronger than that of other layers. The degradation effect followed the order: cathode > upper > lower > middle). Geobacter, Desulfobulbus, and Desulfuromonas belonging to the δ-Proteobacteria class were identified as the dominant electroactive microorganisms in the anode layer, while their relative abundances are quite low in the upper and cathode layers. Pseudomonas is an atrazine-degrading bacterium, but its relative abundance was only 0.13-0.51%. Thus, bioelectrochemistry rather than microbial degradation was the primary driving force.

Insights into sorption and molecular transport of atrazine, testosterone, and progesterone onto polyamide microplastics in different aquatic matrices

Microplastics can act as vectors of a wide class of contaminants in aquatic environments. The sorption behavior of two hormones known to cause adverse effects in biota even in low concentrations (testosterone-TTR and progesterone-PGT), and a pesticide with a high environmental persistence known as endocrine disruptor chemical (atrazine-ATZ) onto polyamide (PA) microplastics is investigated under different aquatic matrices using kinetic and isotherm experiments. The sorption equilibrium is achieved in 48 h, and the experimental results are better fitted by pseudo-2nd-order model. Langmuir isotherm better describes the sorption of the contaminants onto PA microplastics. PGT presents the highest sorption efficiency at around 90%, followed by TTR at 70% and ATZ at approximately 20%. Moreover, ATZ is the contaminant with the highest desorption efficiency (∼65%), indicating its preference for staying solubilized in water. Combining classical molecular dynamics and density functional theory calculations, the sorption energies were calculated as 12-15 kcal mol^-1, 13-16 kcal mol^-1, and 19-22 kcal mol^-1 for PGT, TTR, and ATZ, respectively, showing that PGT needs less energy to be transferred from the solvent network to the PA surface, in agreement with experimental results. The sorption mechanism is driven by hydrogen bonds onto PA outer surface, while the electrostatic interactions dominate the PA inner surface sorption. Moreover, the sorption efficiency is statistically different between the investigated matrices, indicating that physicochemical characteristics of water systems could influence the interactions between PA-contaminant. In seawater, the phenomena of salting-out/in and competitive sorption with saline ions are observed for three contaminants. The PA-contaminant complexes are more polar and soluble than the dissociated ones, which increases the contaminant's co-transport by PA in water.

Prenatal exposure to pesticides and domain-specific neurodevelopment at age 12 and 18 months in Nanjing, China

BACKGROUND

The extensive usage of pesticides has led to a ubiquitous exposure in the Chinese general population. Previous studies have demonstrated developmental neurotoxicity associated with prenatal exposure to pesticides.

OBJECTIVES

We aimed to delineate the landscape of internal pesticides exposure levels from pregnant women's blood serum samples, and to identify the specific pesticides associated with the domain-specific neuropsychological development.

METHODS

Participants included 710 mother-child pairs in a prospective cohort study initiated and maintained in Nanjing Maternity and Child Health Care Hospital. Maternal spot blood samples were collected at enrollment. Leveraging on an accurate, sensitive and reproducible analysis method for 88 pesticides, a total of 49 pesticides were measured simultaneously using gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS). After implementing a strict quality control (QC) management, 29 pesticides were reported. We assessed neuropsychological development in 12-month-old (n = 172) and 18-month-old (n = 138) children using the Ages and Stages Questionnaire (ASQ), Third Edition. Negative binomial regression models were used to investigate the associations between prenatal exposure to pesticides and ASQ domain-specific scores at age 12 and 18 months. Restricted cubic spline (RCS) analysis and generalized additive models (GAMs) were fitted to evaluate non-linear patterns. Longitudinal models with generalized estimating equations (GEE) were conducted to account for correlations among repeated observations. Weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were applied to examining the joint effect of the mixture of pesticides. Several sensitivity analyses were performed to assess the robustness of the results.

RESULTS

We observed that prenatal exposure to chlorpyrifos was significantly associated with a 4 % decrease in the ASQ communication scores both at age 12 months (RR, 0.96; 95 % CI, 0.94-0.98; P < 0.001) and 18 months (RR, 0.96; 95 % CI, 0.93-0.99; P < 0.01). In the ASQ gross motor domain, higher concentrations of mirex (RR, 0.96; 95 % CI, 0.94-0.99, P < 0.01 for 12-month-old children; RR, 0.98; 95 % CI, 0.97-1.00, P = 0.01 for 18-month-old children), and atrazine (RR, 0.97; 95 % CI, 0.95-0.99, P < 0.01 for 12-month-old children; RR, 0.99; 95 % CI, 0.97-1.00, P = 0.03 for 18-month-old children) were associated with decreased scores. In the ASQ fine motor domain, higher concentrations of mirex (RR, 0.98; 95 % CI, 0.96-1.00, P = 0.04 for 12-month-old children; RR, 0.98; 95 % CI, 0.96-0.99, P < 0.01 for 18-month-old children), atrazine (RR, 0.97; 95 % CI, 0.95-0.99, P < 0.001 for 12-month-old children; RR, 0.98; 95 % CI, 0.97-1.00, P = 0.01 for 18-month-old children), and dimethipin (RR, 0.94; 95 % CI, 0.89-1.00, P = 0.04 for 12-month-old children; RR, 0.93; 95 % CI, 0.88-0.98, P < 0.01 for 18-month-old children) were associated with decreased scores. The associations were not modified by child sex. There was no evidence of statistically significant nonlinear relationships between pesticides exposure and RRs of delayed neurodevelopment (P_nonlinearity > 0.05). Longitudinal analyses implicated the consistent findings.

CONCLUSION

This study gave an integrated picture of pesticides exposure in Chinese pregnant women. We found significant inverse associations between prenatal exposure to chlorpyrifos, mirex, atrazine, dimethipin and the domain-specific neuropsychological development (i.e., communication, gross motor and fine motor) of children at 12 and 18 months of age. These findings identified specific pesticides with high risk of neurotoxicity, and highlighted the need for priority regulation of them.

Atrazine sorption on biodegradable microplastics: Significance of microbial aging

The study of the environmental sorption behavior of typical biodegradable microplastics (BMPs) during biodegradation is essential given the different characteristics of BMPs and conventional microplastics (MPs) and the knowledge gap on the sorption capacity of BMPs for pollutants during degradation. In this study, polylactic acid (PLA) and poly (butylene-adipate-co-terephthalate) (PBAT) were chosen as research objects, and the effects of soil microbial aging on their surface properties and atrazine (ATZ) sorption were investigated. The structural composition of the bacterial community was essentially similar between B-PLA and B-PBAT. Microbial aging action created new pores and cavities in PLA, forming microbial films that led to the agglomeration of PLA particles. The microbial aging action destroyed the amorphous regions of PLA and PBAT, resulting in higher crystallinity, and the ester groups broke to form carboxyl groups. The equilibrium sorption (Q_e) of B-PLA increased by 11.12 % compared with PLA, while the Q_e of B-PBAT decreased by 4.95 % compared to PBAT. These results show that soil microbes change the surface properties of PLA and PBAT, thus affecting the sorption mechanism of ATZ, and provide a theoretical premise for the behavior and ecological risk assessment of ATZ in the presence of BMPs.