Pesticides In Soil Research Articles

Interaction of ZnO Nanoparticles with Metribuzin in a Soil–Plant System: Ecotoxicological Effects and Changes in the Distribution Pattern of Zn and Metribuzin

The use of zinc oxide nanoparticles (ZnO NPs), applied as a possible micronutrient source, in conjunction with organic pesticides in agricultural soils has the potential to alter the environmental behavior and toxicity of these chemicals to soil biota. This research examines the joint effects of ZnO NPs and the herbicide metribuzin (MTZ) on phytotoxicity to plants, toxicity to soil microorganisms, and the accumulation of Zn and MTZ in plants. After 23 days, effects on growth, photosynthetic pigment content, and oxidative stress biomarkers in bean plants (Phaseolus vulgaris) and soil enzymatic activities were evaluated. Additionally, the amounts of Zn and MTZ (and the latter’s main metabolites) in soil and plant tissues were quantified. ZnO NPs reduced ammonium oxidase activity and growth among MTZ-stressed plants while reducing photosynthetic pigment levels and enhancing antioxidant enzymatic activities. MTZ had a marginal impact on the availability and accumulation of Zn in plant tissues, although significant effects were observed in some specific cases. In turn, ZnO NPs drastically affected MTZ degradation in soil and influenced MTZ accumulation/metabolization in the bean plants. Our findings indicate that the indirect effects of ZnO NPs, through their interaction with commonly used organic pesticides, may be relevant and should be taken into account in agricultural soils.

Characteristic response of formulation ingredients revealed by ultra high performance liquid chromatography-electrospray ionization-high resolution mass spectrometry-based untargeted screening of pesticides in soil.

Commercial solutions of pesticides consist of two main components: The active substance and the formulation ingredients. These ingredients, mainly composed of polymeric surfactants, are considered inert vis-à-vis the targeted organisms and nature. Nonetheless, a relatively low attention is given to their analysis and fate tracking in the environment. In this context, the current paper, embedded in a large study of fate and impact of formulated pesticides in soil, focuses on the analysis of these formulation ingredients. It mainly highlights and discusses the characteristic response of these ingredients in liquid chromatography-mass spectrometry-based untargeted screening of two commercial herbicides applied on soil. This characteristic response is based on different spectral and chromatographic aspects, as their amplified adducts and double-charged ions formation, or their "wavy" chromatographic profiles and the inversion of their elution order following the polymerization degree. These patterns are briefly discussed in order to explain them, and then thanks to their understanding, 12 different series (165 compounds) of formulation ingredients were outlined and discriminated from active substance and soil metabolites. After, high-resolution and tandem mass spectrometry data were investigated for rapid interseries and intraseries identification-by-chain. In addition, recommendations for methods development and hints on postanalytical data processing for identity determination of these ingredients are given in order to help in enhancing future studies. Limitations of the applied approach are also outlined, and some innovate suggestions are provided based on the described findings.

Spectrophotometric detection of thiram pesticide in vegetables, fruits, soil and water samples using silane-modified silver nanoparticles

Spectrophotometric detection of thiram pesticide in vegetables, fruits, soil and water samples using silane-modified silver nanoparticles

Generalizable consistency of soil quality standards for pesticides: Modeling perspectives

Soil quality standards for pesticides play a crucial role in protecting plants and preventing potential health hazards to humans. Here we discuss modeling approaches to define pesticide soil quality standards from two effect endpoints, which ensures consistency throughout the entire pesticide life cycle from application to human exposure assessment. Given that pesticides are applied in a pulse-like emission pattern and their soil concentrations change over time, both a ceiling legal limit and an average legal limit for pesticide soil quality standards should apply to the initial pesticide application practice and the potential human health effect. The timing intervals for pesticide application and the dissipation half-life in the soil can be used to quantify the relationship between the ceiling and average legal limits. By analyzing primary exposure pathways related to soil contamination, the average legal limit can be linked to theoretical human health risks, which requires a comprehensive evaluation for an adequate safety margin, including human interactions with soil, exposure assessment of soil pesticides, and allocation exposure assessment. To establish acceptable human health risks, the average legal limit can be determined, and the ceiling legal limit can be estimated based on the quantitative relationship between the ceiling and average legal limits. Additionally, we discuss situation-specific factors, including climate-pattern and behavior-pattern factors, to define pesticide soil quality standards to further complete the modeling framework. We hope insights presented in this paper will assist regulatory agencies worldwide in defining pesticide soil quality standards that meet their specific regulatory needs throughout the entire pesticide life cycle.

Hydrolytic Behavior of Novel Pesticide Broflanilide and Its Dissipative Properties in Different Types of Soils.

All pesticides are toxic by nature and pose short- or long-term safety risks to human or the environment, especially when they were used extensively and absence of safety measures. As a new insecticidal active compound with a novel mechanism of action, there is a serious inadequate of information on the hydrolytic behavior of broflanilide in the aqueous environment, as well as its degradation pattern in agricultural soils. In particular, the effects of temperature and pH of the aqueous environment on its hydrolytic behaviors and the dissipation pattern in different types of agricultural soils were still in a dark box. And the further understanding and insights into this insecticidal active ingredient were being deeply conditioned by these doubts. The hydrolysis behavior of broflanilide and the dissipation pattern in soil were systematically investigated by constructing hydrolysis systems with different temperatures and pH values, and conducting spiking experiments in different types of agricultural soil in the laboratory. The obtained results showed that the longest hydrolysis half-life of 10mg/L broflanilide at 25°C was 43.32h (in pH 4.0 buffer), while it was only 12.84h in pH 9.0 buffer. In pH 7.0 buffer, the hydrolysis rate of broflanilide exhibited a significant temperature dependence, as shown by the fact that for every 10°C increase in the system temperature, the corresponding hydrolysis rate will increase about 1.5 times. The dissipation experiments in soils showed that broflanilide was most rapidly dissipated in fluvo-aquic soil (half-life of 1.94days), followed by lime concretion black soil (half-life of 2.53days) and cinnamon soil (half-life of 3.11days), and slower in paddy soil (half-life of 4.03days). It was indicated that broflanilide was a readily degradable pesticide in both aqueous environment and agricultural soil, and it was significantly affected by the temperature and pH of the system.

Adsorption Behavior and Residue Degradation of Triazine Herbicides in Soil Amended with Rice Straw Biochar

The removal of or decrease in pesticide residues in soil has attracted considerable attention, due to the serious pollution of pesticides in soil. The purpose of the study was to explore the adsorption behavior of biochar on pesticides and the impact on the degradation of pesticide residues in soil, providing a basis for the remediation of soil by biochar. Biochars were prepared via pyrolysis of rice straw at a high temperature (300 °C, 400 °C, 500 °C, 600 °C). The individual and competitive adsorption of three triazine herbicides, prometryn, atrazine, and simazine, on biochar was investigated, and the degradation of the herbicide residues in biochar-added soil was determined. The selected herbicides presented similar adsorption characteristics to rice straw biochar, and the amount of herbicides adsorbed increased with higher preparation temperature and the amount of biochar. The rice straw biochar adsorbed the studied herbicides simultaneously, and the adsorption amount decreased as follows: simazine > atrazine > prometryn. The competition adsorption of the selected herbicides on the biochar presented a lower adsorption affinity than that when they are adsorbed individually. The adsorption isotherm was best fitted by the Freundlich model. The half-lives of prometryn, atrazine, and simazine were 9.8~12.6 d, 5.2~8.1 d, and 3.7~5.6 d, respectively. Biochar addition increased the degradation of the evaluated herbicides in soil. The rice straw biochar could be the potential sorbents that can be implemented for the removal of pesticides.

Spatial distribution and temporal trend of organochlorine pesticides in Chinese surface soil.

Although organochlorine pesticides (OCPs) in the Stockholm Convention List were banned for a period of time, the residue of OCPs in environment was still detected recently. Therefore, the continuous environmental monitoring was necessary and important for the deep understanding on the temporal trend of environmental fate of OCPs. In this study, the national scale surface soil samples in 26 provinces of China in 2012 were collected, and 28 OCPs were analyzed. The mean concentrations (ng/g dw) of Σhexachlorocyclohexanes (HCHs), Σdichlorodiphenyltrichloroethane (DDTs), hexachlorobenzene (HCB), and hexachlorobutadiene (HCBD) were 2.47 ± 5.4, 4.29 ± 8.28, 3.33 ± 7.68, and 0.041 ± 0.097, respectively. The correlations between OCPs concentrations with temperature, latitude, and longitude were conducted for the deep study of the spatial distribution pattern of OCPs. It was found that HCHs, HCB, and HCBD are positively correlated with latitude and longitude; however, the correlations were not significant. HCHs followed the secondary distribution pattern, and DDTs followed both the primary and/or secondary distribution patterns. Except for HCB, other OCPs showed a gradual downward trend from 2005 to 2012, indicating the effectiveness of the phase-out of OCPs. In summary, the results of the study provided new insight into the related studies, which will help us to better understand the long-term environmental fate of OCPs on large scales.

Evaluation of Cytotoxicity, Release Behavior and Phytopathogens Control by Mancozeb-Loaded Guar Gum Nanoemulsions for Sustainable Agriculture.

Chemical fungicides are the backbone of modern agriculture, but an alternative formulation is necessary for sustainable crop production to address human health issues and soil/water environmental pollution. So, a green chemistry approach was used to form guar gum nanoemulsions (NEs) of 186.5-394.1 nm containing the chemical fungicide mancozeb and was characterized using various physio-chemical techniques. An 84.5% inhibition was shown by 1.5 mg/mL mancozeb-loaded NEs (GG-1.5) against A. alternata, comparable to commercial mancozeb (86.5 ± 0.7%). The highest mycelial inhibition was exhibited against S. lycopersici and S. sclerotiorum. In tomatoes and potatoes, NEs showed superior antifungal efficacy in pot conditions besides plant growth parameters (germination percentage, root/shoot ratio and dry biomass). About 98% of the commercial mancozeb was released in just two h, while only about 43% of mancozeb was released from nanoemulsions (0.5, 1.0 and 1.5) for the same time. The most significant results for cell viability were seen at 1.0 mg/mL concentration of treatment, where wide gaps in cell viability were observed for commercial mancozeb (21.67%) and NEs treatments (63.83-71.88%). Thus, this study may help to combat the soil and water pollution menace of harmful chemical pesticides besides protecting vegetable crops.

Spatio-temporal distribution of organochlorine pesticides in agricultural soils of southeast China during 2014-2019

Organochlorine pesticides (OCPs) are organic pollutants that are persistent and undegradable in the environment. To investigate their residual concentrations, spatial and temporal distributions, and the relationship with the crops planted, 12 individual OCPs in 687 soil samples from Jiangsu, Zhejiang and Jiangxi provinces of southeast China were examined. The detection frequencies of OCPs in the studied areas were 1.89%–64.9%. The concentrations of dichloro-diphenyl-trichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and endosulfans ranged from 0.01 to 5659 μg/kg, 0.03–3.58 μg/kg, and 0.05–3235 μg/kg, respectively. Jiangsu was mainly contaminated by p,p'-DDT, p,p'-DDD and endosulfan sulfate, Zhejiang was more polluted by OCPs except δ-HCH, and Jiangxi was more vulnerable to the contamination of OCPs except o,p'-DDE. The partial least-squares discrimination analysis (PLS-DA) model with RX2 36.3–36.8% revealed that compounds with similar chemical properties tended to appear in the same year and month. All crop lands were polluted by DDTs and Endosulfans. The highest concentrations of DDTs and Endosulfans were found in citrus and vegetable fields, respectively. This study offers new insight into the layout and partitioning of OCPs in agricultural land and into insecticide management on public health and ecological safety.

Endocrine Disruptors: A Silent Kill

Endocrine disruptors are the substances or environmental factors which causes destruction of different endocrine glands.1 Endocrine-disrupting chemicals contribute to several disease and dysfunction, and incur high associated costs of more than 1% of the GDP of European Union.2 As the endocrine glands are formed by soft, delicate and vulnerable cells, they are prone to the easy destructions by different types of noxious substance like dioxin in meat, flame retardants in furniture, electronics and multipurpose use plastics; frequently used pesticides in food water and soil. Bangladesh Medical Res Counc Bull 2022; 48(3): 172-173

Pesticide residues in agricultural soils in light of their on-farm application history

The application of synthetic pesticides to agricultural fields for the protection of crops leads to the formation of residues in soils. While the short-term behavior of pesticide residues in soils after an application is generally known from laboratory and field studies required for authorization (prospective risk assessments), there is still a lack of in-situ observations that address their long-term fate. Long-term soil monitoring programs, with comprehensive site-specific records of pesticide application data, constitute an invaluable, complementary, retrospective exposure assessment tool to address this gap. Considering the pesticide applications over the past 10–15 years, this study assessed the occurrence of pesticides in agricultural soils of Switzerland and put their presence or absence, as well as their concentrations, in the context of their previous application. The results showed that pesticides could also be detected at sites without a connection to previous applications and that small residual mass fractions of pesticides, even of some non-persistent compounds, were found in soils, years or decades after their last application. This finding points to an environmental issue that may not be adequately captured in prospective risk assessment and calls attention to the need for comprehensive long-term recording and monitoring as a complementary retrospective exposure assessment.

Validation and Simultaneous Monitoring of 311 Pesticide Residues in Loamy Sand Agricultural Soils by LC-MS/MS and GC-MS/MS, Combined with QuEChERS-Based Extraction.

Soil can be contaminated by pesticide residues through agricultural practices, by direct application or through spray-drift in cultivations. The dissipation of those chemicals in the soil may pose risks to the environment and human health. A simple and sensitive multi-residue analytical method was optimized and validated for the simultaneous determination of 311 active substances of pesticides in agricultural soils. The method involves sample preparation with QuEChERS-based extraction, and determination of the analytes with a combination of GC-MS/MS and LC-MS/MS techniques. Calibration plots were linear for both detectors over the range of five concentration levels, using matrix-matched calibration standards. The obtained recoveries from fortified-soil samples ranged from 70 to 119% and from 72.6 to 119% for GC-MS/MS and LC-MS/MS, respectively, while precision values were <20% in all cases. As regards the matrix effect (ME), signal suppression was observed in the liquid chromatography (LC)-amenable compounds, which was further estimated to be negligible. The gas chromatography (GC)-amenable compounds showed enhancement in the chromatographic response estimated as medium or strong ME. The calibrated limit of quantification (LOQ) value was 0.01 μg g-1 dry weight for most of the analytes, while the corresponding calculated limit of determination (LOD) value was 0.003 μg g-1 d.w. The proposed method was subsequently applied to agricultural soils from Greece, and positive determinations were obtained, among which were non-authorized compounds. The results indicate that the developed multi-residue method is fit for the purpose of analyzing low levels of pesticides in soil, according to EU requirements.

Understanding the Physicochemical Behavior of Pesticides in Soil and Water

Pesticides serve as indispensable tools in modern agriculture, yet their widespread use poses environmental challenges, particularly concerning soil and water quality. This abstract presents a comprehensive overview of the physicochemical behavior of pesticides in soil and water systems, crucial for effective pesticide management and environmental protection. Factors influencing pesticide fate and transport, including soil properties, pesticide characteristics, environmental conditions, and management practices, are discussed. Key physicochemical processes such as sorption, degradation, volatilization, and leaching govern pesticide behavior, impacting their persistence and potential environmental risks. Strategies for minimizing pesticide contamination and promoting sustainable agriculture are highlighted, emphasizing the importance of integrated pest management and conservation practices. Through collaborative efforts and informed decision-making, we can mitigate pesticide pollution, preserve natural resources, and safeguard ecosystem health.

Pesticide Residues in French Soils: Occurrence, Risks, and Persistence.

Contamination of the environment by pesticide residues is a growing concern given their widespread presence in the environment and their effects on ecosystems. Only a few studies have addressed the occurrence of pesticides in soils, and their results highlighted the need for further research on the persistence and risks induced by those substances. We monitored 111 pesticide residues (48 fungicides, 36 herbicides, 25 insecticides and/or acaricides, and two safeners) in 47 soils sampled across France under various land uses (arable lands, vineyards, orchards, forests, grasslands, and brownfields). Pesticides were found in 98% of the sites (46 of the 47 sampled), including untreated areas such as organic fields, forests, grasslands, and brownfields, with up to 33 different substances detected in one sample, mostly fungicides and herbicides. The concentrations of herbicides were the highest in soils with glyphosate, and its transformation product, AMPA, contributed 70% of the cumulative herbicides. Risk assessment underlined a moderate to high risk for earthworms in arable soils mostly attributed to insecticides and/or acaricides. Finally, the comparison with pesticide application by farmers underlines the presence of some residues long after their supposed 90% degradation and at concentrations higher than predicted environmental concentrations, leading to questions their real persistence in soils.

A review of the enhanced degradation of pesticides in tropical agricultural soils

Pesticides newly introduced into the soil are normally poorly degraded by native soil microbes. However, studies have demonstrated that repeated exposure of pesticides to soil microbes potentially enhances their biodegradation through selective enrichment of pesticide-metabolising microorganisms, particularly when the compound is used as a carbon (C) or nitrogen (N) and energy source. Enhanced degradation of recalcitrant compounds in soil has a significant environmental impact, as the chemicals are less likely to contaminate environmental ecosystems. The authors have undertaken several studies to isolate these adapted microbes that rapidly degrade chemicals hitherto known to be recalcitrant in soil. These microbes could potentially be used for bioremediation (bioaugmentation). In addition, other studies have shown their potential to remove pesticide contamination from the environment by the use of organic materials locally generated as organic amendments (biostimulation). In this review, the various methods used in the course of the authors’ studies in determining the utilisation of selected chemicals (pesticides) by adapted microbes as a source of carbon and nitrogen for growth and energy are discussed. This review also presents some of the compounds that the authors have worked with and the successes registered in isolating key degraders of the respective pesticides and the extent to which the locally generated organic materials are able to enhance the degradation of the respective chemicals in soil.

A new sample preparation approach for the analysis of 98 current-use pesticides in soil and herbaceous vegetation using HPLC-MS/MS in combination with an acetonitrile-based extraction

A simple acetonitrile-based extraction method for the determination of 98 current-use pesticides (CUPs) in soil and herbaceous vegetation using HPLC-ESI-MS/MS is reported. The method was optimized in terms of extraction time, buffer (ammonium formate) ratio, and graphitized carbon black (GCB) ratio for the clean-up of vegetation. The validated method yielded accuracy in terms of percentage recovery of 71–125% (soil) and 70–117% (vegetation) for the majority of 98 CUPs. The precision in terms of relative standard deviation was at 1–14% (soil), and 1–13% (vegetation). Matrix-matched calibration curves exhibited good linearities (R2 > 0.99). The limits of quantitation ranged between 0.008 and 21.5 μg kg−1 in soil and vegetation. The reported method was applied to soils and vegetation from 13 agricultural sites across Germany. Overall, 44 of the 98 common CUPs were detected in our samples and the qualitative load is well above the average for arable soils in the EU.

A screening study of the spatial distribution and cumulative toxicity of agricultural pesticides in the European Union’s waters

Pesticides can be an important stressor to aquatic ecosystems, and their use is strictly regulated in the European Union (EU). However, data on the use of pesticides are rather limited and poorly available, and monitoring is often insufficient to characterize their actual exposure and impact. The aim of the work presented here is to harness the limited data available and assess, for the first time, the distribution of concentrations and toxicity of 148 pesticide active substances (AS) for the whole EU. Starting from available estimates of pesticide use in agriculture and a simple screening-level model of their fate and transport, we quantify pesticide concentrations in soil and water. A comparison with monitoring data shows that predicted water concentrations are in plausible orders of magnitude, hence the model can be regarded as a first-approximation representation of the distribution of pesticides in the environment. The toxicity of individual pesticide active substances (AS) is characterized by their concentrations divided by the respective no observed effect concentrations (NOEC) for aquatic organisms, which represents the “toxic units” (TU) of each AS. The cumulative toxicity of pesticides in soils and streams of the EU is obtained by summing the TU of individual AS. We estimate that the toxicity of individual AS is generally well below 0.1 TU, indicating relatively safe environmental exposure. However, the cumulative toxicity of a mixture of AS can exceed 0.1 toxic units (TU) for more than 27% of the length of the EU’s stream network, and 1 TU for more than 4%. The cumulative toxicity at a given location is driven by only a handful of AS, but these differ from site to site reflecting the variability of pesticide use. Still, we estimate that only about 20 AS out of 148 appear among the top contributors to cumulative toxicity in most cases. While our assessment suggests a relatively widespread risk due to pesticide pollution, it also points to the important limitations concerning knowledge of pesticide use and monitoring of pesticide occurrence in the environment. These limitations need to be addressed in order to evaluate more accurately the effectiveness of EU pesticide policies. The assessment represents a proof-of-concept of a method that can be applied in support of the monitoring of pesticide policies implementation in the EU and elsewhere, once pesticide use can be estimated.

Sinomonas terrae sp. nov., Isolated from an Agricultural Soil.

While searching for the bacteria which are responsible for degradation of pesticide in soybean field soil, a novel bacterial strain, designated 5-5T, was isolated. The cells of the strain were Gram-staining-positive, aerobic and non-motile rods. Growth occurred at 10-42oC (optimum, 30oC), pH 5.5-9.0 (optimum, pH 7.0-7.5), and 0-2% (w/v) NaCl (optimum, 1%). The predominant fatty acids were C15:0 anteiso, C17:0 anteiso, and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The predominant menaquinone was MK-9 (H2). Diphosphatidylglycerol, glycolipids, phosphatidylinositol, and phosphatidylglycerol were the major polar lipids. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain 5-5T is a member of the genus Sinomonas and its closest relative is Sinomonas humi MUSC 117T, sharing a genetic similarity of 98.4%. The draft genome of strain 5-5T was 4,727,205 bp long with an N50 contig of 4,464,284 bp. Genomic DNA G+C content of strain 5-5T was 68.0 mol%. The average nucleotide identity (ANI) values between strain 5-5T and its closest strains S. humi MUSC 117T and S. susongensis A31T were 87.0, and 84.3 % respectively. In silico DNA-DNA hybridization values between strain 5-5T and its closest strains S. humi MUSC 117T and S. susongensis A31T were 32.5% and 27.9% respectively. Based on the ANI and in silico DNA-DNA hybridization analyses, the 5-5T strain was considered as novel species belonging to the genus Sinomonas. On the basis of the results from phenotypic, genotypic and chemotaxonomic analyses, strain 5-5T represents a novel species of the genus Sinomonas, for which the name Sinomonas terrae sp. nov. is proposed. The type strain is 5-5T (=KCTC 49650T=NBRC 115790T).

Mini-review highlighting toxic effects of triflumuron in insects and mammalian systems.

Pesticides have been used to kill pests such as insects, fungi, rodents, and unwanted plants. As these compounds are potentially toxic to the target organisms, they could also be harmful to human health and the environment. Several chronic adverse effects have been identified even after months or years of exposure. The adverse effects of pesticides on the agricultural ecosystem have been a matter of concern in recent decades. In this review, we present an overview of the studies, including our previous studies, monitoring currently used pesticides in the Tunisian agricultural soils that belong to the class of insect growth regulators (IGRs). Triflumuron (TFM) is a benzoyl phenyl urea insecticide belonging to the class of IGRs. TFM is widely used around the world to increase crop yield by protecting them from damage caused by insects. TFM works by inhibiting the synthesis of chitin, an essential part of the insect cuticle, making it susceptible to pathogens and deformities. Consequently, insects become more susceptible to pathogens and malformations. However, studies revealing its toxicity and its mode of action in mammalian systems remain very limited. The aim of this review is to better inform the community about the impact of TFM on crops, the environment, and human beings by summarizing its toxic effects.

Composition, Distribution, and Source Apportionment of Organochlorine Pesticides (OCPs) in Soil of a Chemical Industrial Park and its Surrounding in the Northeast of Qinghai-Tibet Plateau

Composition, Distribution, and Source Apportionment of Organochlorine Pesticides (OCPs) in Soil of a Chemical Industrial Park and its Surrounding in the Northeast of Qinghai-Tibet Plateau