Prioritizing agricultural pesticides to protect human health: A multi-level strategy combining life cycle impact and risk assessments

Pesticides in fish from the Uruguay River and markets in Argentina and health risk assessment

Organochlorine, organophosphate, triazole, and strobilurin pesticides were determined in fish samples. Relative standard deviations lower than 9.3% were obtained for organochlorine pesticides and 10.8% for other pesticides. Accuracy ranged from 73% to 119% for organochlorine pesticides and 80.4% to 116% for organophosphate, triazole, and strobilurin pesticides. A total of 28 pesticides were analysed and 7 of them were detected (exceeding 10 µg/kg) in some samples, with the highest concentration recorded at 68.5 µg/kg, corresponding to heptachlor epoxide A. The pesticide most frequently detected was β HCH, found in 30 of the 100 analysed samples. Hazard Quotient values were estimated for men, women, and children. These values exceeded 1 for heptachlor epoxide in women and children, as well as for endrin in children. These findings emphasise the need for stricter controls to reduce fish contamination and mitigate health risks.

From economic threshold to economic injury level: Modeling the residual effect and delayed response of pesticide application

Integrated Pest Management (IPM) poses a challenge in determining the optimal timing of pesticide sprays to ensure that pest populations remain below the Economic Injury Level (EIL), due to the long-term residual effects of many pesticides and the delayed responses of pest populations to pesticide sprays. To address this issue, a specific pesticide kill-rate function is incorporated into a deterministic exponential growth model and a subsequent stochastic model. The findings suggest the existence of an optimal pesticide spraying cycle that can periodically control pests below the EIL. The results regarding stochasticity indicate that random fluctuations promote pest extinction and ensure that the pest population, under the optimal cycle, does not exceed the EIL on average, even with a finite number of IPM strategies. All those confirm that the modeling approach can accurately reveal the intrinsic relationship between the two key indicators Economic Threshold and EIL in the IPM strategy, and further realize the precise characterization of the residual effect and delayed response of pesticide application.

Those That Remain Caught in the "Organic Matter Trap": Sorption/Desorption Study for Levelling the Fate of Selected Neonicotinoids

With projections suggesting an increase in the global use of neonicotinoids, contemporary farmers can get caught on the "pesticide treadmill", thus creating ecosystem side effects. The aim of this study was to investigate the sorption/desorption behavior of acetamiprid, imidacloprid, and thiacloprid that controls their availability to other fate-determining processes and thus could be useful in leveling the risk these insecticides or their structural analogues pose to the environment, animals, and human health. Sorption/desorption isotherms in four soils with different organic matter (OC) content were modelled by nonlinear equilibrium models: Freundlich's, Langmuir's, and Temkin's. Sorption/desorption parameters obtained by Freundlich's model were correlated to soil physico-chemical characteristics. Even though the OC content had the dominant role in the sorption of the three insecticides, the role of its nature as well as the chemical structure of neonicotinoids cannot be discarded. Insecticides sorbed in the glassy OC phase will be poorly available unlike those in the rubbery regions. Imidacloprid will fill the sorption sites equally in the rubbery and glassy phases irrespective of its concentration. The sorption of thiacloprid at low concentrations and acetamiprid at high concentrations is controlled by hydrophilic aromatic structures, "trapping" the insecticides in the pores of the glassy phase of OC.

Study on the toxicity prediction model ofacetolactate synthase inhibitor herbicides based on human serum albumin and superoxide dismutase binding information

Toxicity significantly influences the successful development of drugs. Based on the toxicity prediction method (carrier protein binding information-toxicity relationship) previously established by the our group, this paper introduces information on the interaction between pesticides and environmental markers (SOD) into the model for the first time, so that the toxicity prediction model can not only predict the toxicity of pesticides to humans and animals, but also predict the toxicity of pesticides to the environment. Firstly, the interaction of acetolactate synthase inhibitor herbicides (ALS inhibitor herbicides) with human serum albumin (HSA) and superoxide dismutase (SOD) was investigated systematically from theory combined with experiments by spectroscopy methods and molecular docking, and important fluorescence parameters were obtained. Then, the fluorescence parameters, pesticides acute toxicity LD50 and structural splitting information were used to construct predictive modeling of ALS inhibitor herbicides based on the carrier protein binding information (R2 = 0.977) and the predictive modeling of drug acute toxicity based on carrier protein binding information and conformational relationship (R2 = 0.991), which had effectively predicted pesticides toxicity in humans and animals. To predict potential environmental toxicity, the predictive modeling of drug acute toxicity based on superoxide dismutase binding information was established (R2 = 0.883) by ALS inhibitor herbicides-SOD binding information, which has a good predictive ability in the potential toxicity of pesticides to the environment. This study lays the foundation for developing low toxicity pesticides.

Global assessment of honeybee exposure to pesticides through guttation consumption: An indicator approach

Guttation consumption is a potential pathway of pesticide residue exposure in honeybees. However, modeling tools for assessing honeybee exposure to pesticide residues in guttation drops are lacking. In this study, we propose an indicator-based approach for qualitatively or quantitatively analyzing the guttation-based exposure pathway, allowing us to conduct region-specific pesticide residue exposure assessments for honeybees. Exposure scores (the product of guttation production and residue level scores) were established to compare or rank honeybee exposure to pesticide residues via guttation intake across locations using three specified indicators (i.e., air temperature, relative humidity, and precipitation intensity). Warm, dry regions had high residue level scores (indicating high residue levels in guttation), whereas cold, wet regions had high guttation production scores (indicating high possibilities of guttation formation on leaf surfaces); their exposure scores were a combination of these two values. We evaluated and ranked honeybee exposure to imidacloprid residue across regions in Brazil, China, the United States, and selected European Union member states, revealing that pesticide application in many Brazilian federative units may raise honeybee risks due to high exposure scores. We also compared the guttation pathway to other common exposure pathways (nectar and pollen), suggesting that for some moderately lipophilic compounds, the guttation exposure pathway may not be ignored and should be further evaluated.

Water quality, human health risk, and pesticides accumulation in African catfish and Nile tilapia from the Kitchener Drain-Egypt

Pesticides are toxic and could negatively impact humans and the ecosystem. The Kitchener Drain is among the longest drains in Egypt and carries a wide range of wastewater from the agriculture sector, which contains pesticides and may pollute the ecosystem. Thus, water quality, human health risk, and pesticide accumulation in African catfish and Nile tilapia from the Kitchener Drain-Egypt. The water and fish samples were collected from Kitchener Drain in Kafr Elsheikh Governorate, Egypt, during the four seasons. The results indicated that heptachlor and diazinon were undetected during the four seasons. However, endosulfan, chlorpyrifos, and dicofol were detected in winter and autumn. Only p,p'-DDT was detected during spring. Endosulfan, heptachlor, and aldrin were detected in Nile tilapia during winter. Only heptachlor and aldrin were detected during spring. Endosulfan, heptachlor, dicofol, p,p'-DDT, chlorpyrifos, and diazinon were detected in the autumn season. In summer, dicofol and p,p'-DDT were detected, while endosulfan, heptachlor p,p'-DDT, aldrin, chlorpyrifos, and diazinon were not detected. In African catfish, endosulfan, heptachlor, dicofol, and p,p'-DDT were detected during winter, while chlorpyrifos, aldrin, and chlorpyrifos, aldrin, and diazinon were not detected. In the spring season, endosulfan, heptachlor, and aldrin were detected. Endosulfan, heptachlor, dicofol, p,p'-DDT, aldrin, chlorpyrifos, and diazinon were detected in the autumn season. Similarly, in the summer season, endosulfan, heptachlor, dicofol, p,p'-DDT, aldrin, chlorpyrifos, and diazinon were detected. The sequence of estimated daily intake (EDI) in Nile tilapia during the four seasons is heptachlor > endosulfan > dicofol > p,p'-DDT > aldrin > diazinon > chlorpyrifos. The sequence of EDI in African catfish during the four seasons is endosulfan > p,p'-DDT > heptachlor > aldrin > dicofol > diazinon > chlorpyrifos. In conclusion, the results confirmed the absence of a hazard index for consuming Nile tilapia and African catfish collected from the Kitchener drain.

Ecological risk assessment of pesticides on soil biota: An integrated field-modelling approach

Pesticide residues in soils can cause negative impacts on soil health as well as soil biota. However, research related to the toxicity and exposure risks of pesticides to soil biota are scarce, especially in the North China Plain (NCP) where pesticides are intensively applied. In this study, the occurrence and distribution of 15 commonly used pesticides in 41 fields in Quzhou county in the NCP were determined during the growing season in 2020. The ecological risks of pesticides to the soil biota, including earthworms, enchytraeids, springtails, mites and nitrogen mineralization microorganisms, were assessed using toxicity exposure ratios (TERs) and risk quotient (RQ) methods. Based on pesticide detection rates and RQs, pesticide hazards were ranked using the Hasse diagram. The results showed that pesticides were concentrated in the 0-2 cm soil depth. Chlorantraniliprole was the most frequently detected pesticide with a detection rate of 37%, while the highest concentration of 1.85 mg kg^-1 was found for carbendazim in apple orchards. Chlorpyrifos, carbendazim and imidacloprid posed a chronic exposure risk to E. fetida, F. candida and E. crypticus with the TERs exceeding the trigger value. Pesticide mixtures posed ecological risks to soil biota in 70% of the investigated sites. 47.5% of samples were ranked as high-risk, with the maximum RQ exceeding 490. According to the Hasse diagram, abamectin, tebuconazole, chlorantraniliprole and chlorpyrifos were ranked as the most hazardous pesticides for soil biota in the study region, indicating that alternative methods of pest management need to be considered. Therefore, practical risk mitigation solutions are recommended, in which the use of hazardous pesticides would be replaced with low-risk pesticides with similar functions from the Hasse diagram, or with biopesticides.

Impact of historical legacy pesticides on achieving legislative goals in Europe

Pesticides are widely used in agriculture to optimise food production. However, the movement of pesticides into water bodies negatively impacts aquatic environments. The European Union (EU) aims to make food systems fair, healthy and environmentally friendly through its current Farm to Fork strategy. As part of this strategy, the EU plans to reduce the overall use and risk of chemical pesticides by 50 % by 2030. The attainment of this target may be compromised by the prevalence of legacy pesticides arising from historical applications to land, which can persist in the environment for several decades. The current EU Farm to Fork policy overlooks the potential challenges of legacy pesticides and requirements for their remediation. In this review, the current knowledge regarding pesticide use in Europe, as well as pathways of pesticide movement to waterways, are investigated. The issues of legacy pesticides, including exceedances, are examined, and existing and emerging methods of pesticide remediation, particularly of legacy pesticides, are discussed. The fact that some legacy pesticides can be detected in water samples, more than twenty-five years after they were prohibited, highlights the need for improved EU strategies and policies aimed at targeting legacy pesticides in order to meet future targets.

Chlorination disinfection by-products in Southeast Asia: A review on potential precursor, formation, toxicity assessment, and removal technologies

This review discusses disinfection by-products' (DBPs) potential precursors, formation, and toxicity, alongside available research on the treatment of DBPs in Southeast Asian countries' water sources. Although natural organic matter (NOM) in the form of humic and fulvic acids is the major precursor of DBPs formation, the presence of anthropogenic organic matter (AOM) also plays essential roles during disinfection using chlorine. NOM has been observed in water sources in Southeast Asian countries, with a relatively high concentration in peat-influenced water sources and a relatively low concentration in non-peat-influenced water sources. Similarly, AOMs, such as microplastics, pharmaceuticals, pesticides, and endocrine-disrupting chemicals (EDCs), have also been detected in water sources in Southeast Asian countries. Although studies regarding DBPs in Southeast Asian countries are available, they focus on regulated DBPs. Here, the formation potential of unregulated DBPs is also discussed. In addition, the toxicity associated with extreme DBPs' formation potential, as well as the effectiveness of treatments such as conventional coagulation, filtration, adsorption, and ozonation in reducing DBPs' formation potential in Southeast Asian sources of water, is also analyzed.

[Determination of 107 typical pesticides and metabolites in raw water and drinking water by online-solid phase extraction coupled with ultra performance liquid chromatography-triple quadrupole mass spectrometry]

In order to monitor the risk of pesticide pollutants in drinking water, an analytical method based on online-solid phase extraction coupled with ultra performance liquid chromatography-triple quadrupole mass spectrometry (online-SPE-UPLC-MS/MS) was established for the simultaneous rapid screening and determination of 107 pesticides and metabolites (organophosphorus, organic nitrogen, organic heterocycle, carbamate, amide, benzoyl urea, neonicotinoid, etc.) in raw water and drinking water. Different injection volumes (5, 10, and 15 mL) were compared. The detection response increased with an increase in the injection volume, but the matrix effect also became more pronounced. Under the premise of ensuring the sensitivity of the method and meeting the detection requirements, the injection volume was selected as 5 mL. Accordingly, the samples were filtered through a 0.22-μm hydrophilic polytetrafluoroethylene filter, and then, 5 mL samples were injected into the online-SPE system by the automatic sampler. After adsorption on an X Bridge C₁₈ online-SPE column, the samples were washed with pure water and eluted by gradient elution using acetonitrile and 0.1% formic acid aqueous solution as the mobile phases, with separation on an ACQUITY HSS T₃ column. The samples were detected by multiple reaction monitoring with electrospray ionization in positive and negative ion modes, and quantified by an external standard method. Using raw water and drinking water as the sample matrices, the accuracy and precision of the method were verified. The 107 pesticides and metabolites showed good linear relationships in different ranges with correlation coefficients (r²)>0.995. The limits of detection (LODs, S/N=3) of the method were 0.03-1.5 ng/L, and the limits of quantification (LOQs, S/N=10) were 0.1-5.0 ng/L. The target pesticides were spiked at concentration levels of 1, 20, and 50 ng/L. The spiked recoveries of the 107 targets in raw water and drinking water samples were 60.6%-119.8% and 61.2%-119.0%, respectively. The corresponding relative standard deviations (RSDs, n=6) were 0.3%-18.6% and 0.4%-17.1%. The pesticide residues in raw water and drinking water were determined by this method. Amide herbicides, triazine herbicides, triazole insecticides, carbamate insecticides, and neonicotinoid insecticides had high detection rates. The detected concentrations ranged from 0.1 to 97.1 ng/L in raw water and from 0.1 to 93.6 ng/L in drinking water. The sample consumption of online-SPE method was lower than that in the traditional off-line SPE methods, which greatly improved the convenience of sample collection, storage, and transportation. The samples only need to be filtered before injection and analysis. The method is simple to operate and shows good reproducibility. With this online-SPE method, only 23 min were required from online enrichment to detection completion. The developed method has the advantages of high analytical speed and high sensitivity. The method is suitable for the trace analysis and determination of 107 typical pesticides in raw water and drinking water, which effectively improves the detection efficiency of pesticides in water and has high potential for practical application. It can extend technical support for the pollution-level analysis of typical pesticides and metabolites in drinking water and provide an objective basis for human health risk assessment.

Risk cognition, agricultural cooperatives training, and farmers' pesticide overuse: Evidence from Shandong Province, China

Introduction

Pesticides are widely and excessively used in the world. Reducing pesticide overuse is an important measure to protect the environment and human health.

Methods

Based on the survey data of 518 farmers in Shandong Province, China, using the Logit model to empirically test the effect of risk cognition on farmers' pesticide overuse behavior and the moderating effect of cooperatives training on the effect of risk cognition on farmers' pesticide overuse behavior.

Results and discussion

We found that 21.24% of farmers overused pesticides. The three dimensions of risk cognition have significant negative effects on farmers' behavior of excessive pesticide use, among which the human health risk cognition has the largest impact (0.74), followed by food safety risk cognition (0.68) and ecological environment risk cognition (0.63). Cooperatives training has a positive moderating effect on the relationship between risk cognition and pesticide overuse behavior, that is, when risk cognition matches farmers participating in cooperatives training, the effect on reducing pesticide overuse is more significant. Years of education, planting scale and detection frequency of pesticide residues have significant effects on farmers' pesticide overuse.

Conclusions

The government should help farmers reduce pesticide overuse by improving risk cognition, developing agricultural cooperatives and perfecting guarantee conditions.