Interactions Of Pesticides Research Articles

Pesticide interactions and risks of sperm chromosomal abnormalities.

Disentangling the separate and synergistic effects of chemicals poses methodological challenges for accurate exposure assessment and for investigating epidemiologically how chemicals affect reproduction. We investigated combined exposures to ubiquitous contemporary use pesticides, specifically organophosphates (OP) and pyrethroids (PYR), and their association with germ cell abnormalities among adult men. Fluorescence in situ hybridization was used to determine disomy in sperm nuclei and urine was analyzed for concentrations of PYR metabolites (3-phenoxybenzoic acid; 3PBA) and OP dialkyl phosphate (DAP) metabolites. Incidence rate ratios using Poisson models were estimated for each disomy type by exposure quartile of DAP metabolites and 3PBA, controlling for confounders. The shape of the associations between PYRs, OPs and disomy were frequently nonmonotonic. There were consistent interactions between OP and PYR metabolite concentrations and the risk for sperm abnormalities. Taking both chemicals into account simultaneously resulted in quantitatively different associations than what was reported previously for OPs and PYRs separately, demonstrating the importance of modeling multiple concentrations simultaneously. Methods investigating interactions using Poisson models are needed to better quantify chemical interactions and their effects on count-based health outcomes, the importance of which was shown here for germ cell abnormalities.

Development of a new solvent‐assisted dispersive solid‐phase extraction followed by ion mobility spectrometry for trace determination of organophosphorus pesticides in environmental water samples

AbstractIn this research, an effective sample preparation method called solvent‐assisted dispersive solid‐phase extraction followed by corona discharge ion mobility spectrometry was proposed for the trace determination of organophosphorus pesticides in environmental water samples. In this method, to maximize the interaction surface between target analytes and sorbent, the sorbent was dispersed into the aqueous sample. In this technique, the sorbent was dispersed at very low levels using a solution of sorbent and disperser solvent into the aqueous sample. Then, a cloudy solution was created by dispersing the sorbent particles in aqueous solution. After the interaction of organophosphorus pesticides and benzil, the cloudy solution was centrifuged and organophosphorus pesticides in the solid phase were dissolved in ethanol. In order to obtain the best extraction efficiency, the optimization of parameters affecting this method was examined. After optimization, the results were obtained as follows: pH of solution: 7.0, sorbent: benzil, 2% w/v, disperser solvent: ethanol, 500 µL, and centrifuge: centrifuged at 6000 rpm for 2 min. The presented method showed low method detection limit (0.3 ng mL−1), excellent preconcentration factor (368–376), good linearity (>0.994), repeatability (RSD < 4.1%), and high recoveries (92–94%).

Analysis and DNA interaction of the profluralin herbicide

The increasing use of pesticides is a major health issue. There is therefore a need for improved analytical methods and more knowledge on the interaction of pesticides with living organisms. Here, we developed the analysis of profluralin in water and soils by cyclic voltammetry, square-wave voltammetry and square-wave adsorptive stripping voltammetry. We also studied the interaction between profluralin and double-stranded DNA. Results of cyclic voltammetric studies indicate that the reduction processes have an irreversible and adsorption-like character, as a possible consequence of the reduction of nitro groups of profluralin. Quantification was found linear from 60 to 800 nmol L−1 with a detection limit of 17 nmol L−1 using square-wave adsorptive stripping voltammetry. Results of interactions with double-stranded DNA from salmon sperm revealed that profluralin forms a complex with DNA by electrostatic binding. Values of Gibbs free energy confirmed that formation of profluralin–DNA complex is spontaneous and favourable.

Highly sensitive plasmonic metal nanoparticle-based sensors for the detection of organophosphorus pesticides

Plasmonic nanoparticles offer attractive benefits for the detection of environmental contaminants due to their high extinction coefficients and unique optical properties. Excess use of OP pesticides has been found to have adverse effects on human health and the environment. Here, we demonstrate the use of plasmonic silver (Ag), gold (Au) and bimetallic silver-gold (Ag-Au) nanoparticles (NPs) to detect and distinguish between organophosphorus (OP) pesticides. The NPs were found to detect the thion pesticides: ethion, parathion, malathion, and fenthion) in real time. In each case, the interaction of the pesticides with the plasmonic NPs were found to result in wavelength shifts of the localized surface plasmon resonance (LSPR) accompanied by color changes. The wavelength shifts were characteristic of the pesticide structure and concentration. The interaction between the sensors and the pesticide was a result of the soft metal surface binding to the soft sulfur atom of the pesticide. Similarly, oxon pesticides showed no effect on the LSPR of the NPs. The three plasmonic NPs showed limits of detections (LOD) in ppm range for all pesticides under real-time analysis. The LOD of Ag NPs with ethion, fenthion, malathion, and parathion were 9 ppm, 11 ppm, 18 ppm, and 44 ppm, respectively. The LOD of Au NPs with ethion, fenthion, malathion, parathion were 58 ppm, 53 ppm, 139 ppm, and 3203 ppm, respectively. Ag-Au NPs with ethion, fenthion, malathion, and parathion showed LOD values of 228 ppm, 231 ppm, 1189 ppm, and 1835 ppm, respectively. The ability of the plasmonic NPs to detect the selected pesticides in natural environments was tested under simulated natural conditions in the presence of dissolved organic matter (DOM). Steep gradients in the sedimentation plots revealed that the time dependent interaction of each OP pesticide with the NP surface was accompanied by a considerable change in the LSPR indicative of colloidal destabilization over time. All pesticides showed nearly the same trend in their sedimentation with the plasmonic NPs. The stability of the nanoparticles in the colloidal medium was described by classical DLVO theory, which showed that the net interaction was attractive.

A study on the molecular existing interactions in nanoherbicides: A chitooligosaccharide/tripolyphosphate loaded with paraquat case

Several modified release nanoformulations have been developed for pesticides to improve their physicochemical stability as well as to reduce their toxicity and bioavailability in the environment and human health. Nevertheless, studies related to the molecular interactions of pesticides with nanocarriers are scarce, although the study of the molecular interactions of nanoparticles with pesticides is important to correlate with the nanoparticle structure and biological activity. Thus, the goal of this study is to gain insights on the molecular interactions between a model of nanoparticles (chitosan/tripolyphosphate, CH/TPP) and the herbicide paraquat (PQ). The system was defined using a very simple Coarse-Grained model where sets of atoms having similar properties are replaced by beads (or pearls). Several dissipative particle dynamics (DPD) simulations with different PQ concentrations were initially performed to find the conditions for breaking the triple interaction. All simulations yielded strong CH/TPP/PQ interactions, and the introduction of a new type of bead for distinguishing between the CH nitrogen atoms and the PQ nitrogen atoms appeared to be necessary. Design of experiments was used for finding reasonable CH/TPP/PQ interaction values. Only one simulation among all the carried out had quite good interaction and large areas showing the CH/TPP/PQ triple interaction. Those repulsion constant values were used along this research. The effect of the order of addition was also studied. The results from our simulations and experimental issues allow ensuring that different ways of adding CH, TPP, and PQ definitely affect the ending results.

Direct and indirect effects of pesticides on a benthic grazer during its life cycle

BackgroundMacroinvertebrates in aquatic ecosystems are repeatedly exposed to pesticides during their life cycle. Effects of consecutive exposure during different life stages and possible synergistic effects are not addressed in the standardized hazard assessment. The present study investigated two environmentally relevant exposure scenarios in batch (microcosm) and artificial indoor stream (mesocosm) experiments using the larvae of the mayfly Rhithrogena semicolorata (grazer) and natural aufwuchs. Grazers were analysed regarding growth, physiological condition, and drift behaviour, while the aufwuchs was analysed in terms of biomass using the particulate organic carbon as well as the chlorophyll a content. The aim was to reveal direct and indirect effects of an herbicide exposure during autumn on juvenile grazers and an insecticide exposure during spring on semi-juvenile grazers.ResultsDirect and indirect effects were found in both exposure scenarios at environmentally relevant concentrations. In the herbicide exposure scenario with terbutryn, clear direct effects on the aufwuchs community with a LOEC of 0.38 µg L−1 were found. Effect levels of grazers due to indirect effects were equal, with the overnight drift being the most sensitive grazer endpoint. In the insecticide exposure scenario, clear lethal and sub lethal effects of lambda-cyhalothrin were evident. Derived LC50 values for the artificial indoor stream and batch experiment were 2.42 µg g−1 OC (69 days) and 1.2 µg g−1 OC (28 days), respectively. Sub lethal effects in terms of increased drift as well-reduced growth and triglyceride levels were found at concentrations of 1.4 and 0.09 µg g−1 OC (LOECs). These results were confirmed by the batch experiment, which revealed effect values in the similar range. Finally, a clear indirect effect of the insecticide on the aufwuchs was evident in the batch experiment with an LOEC at 0.9 µg g−1 OC.ConclusionToxicity Exposure Ratios calculated with the derived effect values indicate a risk for the investigated grazer by both pesticides. Moreover, observed indirect effects during the herbicide exposure seem to be able to affect the grazers during a second exposure with an insecticide, due to reduced physiological conditions. We suggest further research with time-shifted exposure scenarios to gain a better understanding of the complex interactions of pesticides with the life cycle and the food webs of macroinvertebrates.

Interaction of Chemical Pesticides and Their Formulation Ingredients with Microbes Associated with Plants and Plant Pests.

Chemical pesticides and their formulation ingredients can have unintended effects on microbes associated with plants and plant pests. These effects can be due to direct effects on the microbes or to effects on crops or weeds that subsequently affect the microbes. In addition to fungicides, some insecticides, herbicides, and formulation compounds are toxic to plant pathogenic microbes, as well as to potentially beneficial microbes, such as those that infect insect pests. These chemicals, especially herbicides, can also indirectly affect microbes through their effects on crops and weeds. For example, glyphosate strongly impairs shikimic acid pathway-based plant defenses to microbial diseases in glyphosate-susceptible plants, significantly increasing its efficacy as an herbicide. Some herbicides induce plant defenses against plant pathogens. For a complete understanding of integrated pest management and overall cost/benefit of pesticide use, much more information is needed on microbial/pesticide interactions.

The effect of antibiotics on the persistence of herbicides in soil under the combined pollution

Antibiotic contamination in agricultural lands through manure application causes changes in soil enzyme activity and the abundance of microbes, which may affect the fate of agrochemicals. A clear understanding of antibiotic–pesticide interactions is very limited. The objective of this study was to investigate the effect of oxytetracycline (OTC) on the persistence of triazine and chloroacetanilide herbicides in soil under a combined application scenario. Soil enzyme activity and the abundance of soil microbes disturbed by OTC were measured. The results showed that OTC inhibited the dissipation of the herbicides and the effect depended on OTC concentration. For example, the half-lives of acetochlor increased from 6.9 days to 21.6 days with the presence of OTC at 50 mg/kg. It was also found the dissipation of the herbicides would still be affected after a month of OTC exposure at high concentration. Co-application also decreased activity of soil urease, dehydrogenase and catalase during earlier incubation periods, then recovered gradually. Furthermore, OTC reduced the abundance of fungi and bacteria, which might relate to inhibition of herbicide dissipation. Co-application of antibiotics and herbicides resulted in greater herbicide persistence, possibly increasing risk of environmental contamination.

Interactions of organophosphorus pesticides with solute carrier (SLC) drug transporters

1. Organophosphorus pesticides (OPs) are known to interact with human ATP-binding cassette drug efflux pumps. The present study was designed to determine whether they can also target activities of human solute carrier (SLC) drug transporters.2. The interactions of 13 OPs with SLC transporters involved in drug disposition, such as organic cation transporters (OCTs), multidrug and toxin extrusion proteins (MATEs), organic anion transporters (OATs) and organic anion transporting polypeptides (OATPs), were mainly investigated using transporter-overexpressing cell clones and fluorescent or radiolabeled reference substrates.3. With a cut-off value of at least 50% modulation of transporter activity by 100 µM OPs, OAT1 and MATE2-K were not impacted, whereas OATP1B1 and MATE1 were inhibited by two and three OPs, respectively. OAT3 activity was similarly blocked by three OPs, and was additionally stimulated by one OP. Five OPs cis-stimulated OATP2B1 activity. Both OCT1 and OCT2 were inhibited by the same eight OPs, including fenamiphos and phosmet, with IC50 values however in the 3–30 µM range, likely not relevant to environmental exposure.4. These data demonstrated that various OPs inhibit SLC drug transporter activities, especially those of OCT1 and OCT2, but only when used at high concentrations not expected to occur in environmentally-exposed humans.

Interaction of Zinc, Cadmium, Copper, Endosulphan and Dimethoate Pesticides on Fresh Water Fish Channa Punctatus

Interaction of Zinc, Cadmium, Copper, Endosulphan and Dimethoate Pesticides on Fresh Water Fish Channa Punctatus

Plant-Pesticide Interactions and the Global Chloromethane Budget.

Ecological, signaling, metabolic, and chemical processes in plant-microorganism systems and in plant-derived material may link the use of chlorinated pesticides in the environment with plant chloromethane emission. This neglected factor should be taken into account to assess global planetary budgets of chloromethane and impacts on atmospheric ozone depletion.

Interaction of pesticides with natural and synthetic solids. Evaluation in dynamic and equilibrium conditions.

Interactions between pesticides (paraquat, glyphosate, 2,4-D, atrazine, and metsulfuron methyl) and soil organic and inorganic components have been studied in batch experiments by performing adsorption, dissolution, and chemical and photochemical degradation under different conditions. The obtained results confirm that the affinity of a pesticide to the solid surface depends on the nature of both and shows that each reactant strongly affects the mobility of the other one, e.g., anionic pesticides promote the dissolution of the solid humic acid but if this last is retained into the inorganic matrix enhances the adsorption of a cationic pesticide. Adsorption also seems to protect the bonded specie to be chemical degraded, such as shown in two pesticide/clay systems at constant pH. The use of mesoporous silicas could result in a good alternative for pesticide remediation. In fact, the solid shows high adsorption capacity towards paraquat and its modification with TiO2 nanoparticles increases not only the pesticide adsorption but also seems to catalyze its degradation under UV light to less-toxic metabolites. UV-VIS spectroscopy was relevant and novel in such sense. Electrostatic interactions, hydrogen and coordinative bonds formations, surface complexations and hydrophobic associations play a key role in the fate of mentioned pesticides on soil and ground/surface water environments.

A systems-level approach for investigating organophosphorus pesticide toxicity

The full understanding of the single and joint toxicity of a variety of organophosphorus (OP) pesticides is still unavailable, because of the extreme complex mechanism of action. This study established a systems-level approach based on systems toxicology to investigate OP pesticide toxicity by incorporating ADME/T properties, protein prediction, and network and pathway analysis. The results showed that most OP pesticides are highly toxic according to the ADME/T parameters, and can interact with significant receptor proteins to cooperatively lead to various diseases by the established OP pesticide -protein and protein-disease networks. Furthermore, the studies that multiple OP pesticides potentially act on the same receptor proteins and/or the functionally diverse proteins explained that multiple OP pesticides could mutually enhance toxicological synergy or additive on a molecular/systematic level. To the end, the integrated pathways revealed the mechanism of toxicity of the interaction of OP pesticides and elucidated the pathogenesis induced by OP pesticides. This study demonstrates a systems-level approach for investigating OP pesticide toxicity that can be further applied to risk assessments of various toxins, which is of significant interest to food security and environmental protection.

Synergistic Effects of Heavy Metals and Pesticides in Living Systems.

There is a widespread repeated exposure of the population to the pesticides and heavy metals of occupational and environmental origin. Such population is forced to undergo continuous stress imposed by combined exposure of the heavy metals and different classes of the pesticides used in agricultural as well as health practices. The existing reports from several workers have indicated that heavy metals and pesticides in combination may lead more severe impact on the human health when compared to their individual effects. Such a combination of pesticides and heavy metals may also change or influence the detection of exposure. Several studies in past have shown the synergistic toxic effects of heavy metals and pesticides. Such evaluations have revealed the synergistic interactions of various heavy metals and pesticides in animals as well as humans. The aim of the present article is to provide a synthesis of existing knowledge on the synergistic effects of heavy metal and pesticides in living systems. The information included in this article may be useful for different environment protection agencies and policy makers to consider the combined effects of heavy metals and pesticides on humans while designing strategies toward environmental protection and safety regulations about human health.

Toxicological interactions of pesticide mixtures: an update.

Pesticides can interact with each other in various ways according to the compound itself and its chemical family, the dose and the targeted organs, leading to various effects. The term interaction means situations where some or all individual components of a mixture influence each other's toxicity and the joint effects may deviate from the additive predictions. The various mixture effects can be greatly determined by toxicokinetic and toxicodynamic factors involving metabolic pathways and cellular or molecular targets of individual pesticides, respectively. However, the complexity of toxicological interactions can lead to unpredictable effects of pesticide mixtures. Interactions on metabolic processes affecting the biotransformation of pesticides seem to be by far the most common mechanism of synergism. Moreover, the identification of pesticides responsible for synergistic interactions is an important issue for cumulative risk assessment. Cholinesterase inhibiting insecticides (organophosphates and N-methylcarbamates), triazole fungicides, triazine herbicides, and pyrethroid insecticides are overrepresented in the synergistic mixtures identified so far. Since the limited available empirical evidence suggests that synergisms at dietary exposure levels are rather rare, and experimentally occurred at unrealistic high concentrations, synergism cannot be predicted quantitatively on the basis of the toxicity of mixture components. The prediction of biological responses elicited by interaction of pesticides with each other (or with other chemicals) will benefit from using a systems toxicology approach. The identification of core features of pesticide mixtures at molecular level, such as gene expression profiles, could be helpful to assess or predict the occurrence of interactive effects giving rise to unpredicted responses.

Pesticide interaction with environmentally important cations: A molecular dynamics and DFT study of metamitron and fenhexamid

Metamitron (Meta), 4-amino-3-methyl-6-phenyl-1,2,4-triazin-5-one, and fenhexamid (Fen), N-(2,3-dichloro-4-hydroxyphenyl)-1-methylcyclohexanecarboxamide, are active substances of herbicide and fungicide products, respectively, employed in agriculture. When these molecules are spread on crops, an important amount reaches the soil and diffuse through water to deep layers of the soil structure and thus to groundwater tables. To get some insight into the interaction of pesticides with soil, in particular clay surfaces, we have run theoretical calculations. This paper presents preliminary results of this wide and challenging work. Metamitron, fenhexamid and their complexes with one or two Ca2+ and Na+, which are among the most abundant cations into soils, are under investigation. Conformational searches have been performed thanks to Car-Parrinello molecular dynamics (CPMD) simulations from which geometries as well as relative, complexation and interaction energies have been extracted. Thermodynamical complexation values have been calculated for complexes of Meta or Fen with one or two cation(s) in order to understand the complex stability. We found that complexation free energies are comparable for Meta and Fen: around −32kcal/mol with one sodium cation, ≈−130kcal/mol with one Ca2+, and −7kcal/mol with two Na+. With two Ca2+, complexation free energy is four times larger in absolute value for Fen (−40kcal/mol) than for Meta due to longer inter-cation distances in Fen-(Ca2+)2 complexes. The larger values obtained with Ca2+ in the gas phase suggest a strong adsorption of Meta and Fen with Ca2+-montmorillonite clay surfaces.

Interactions of Pesticides with Environment and Environmentally Friendly Approaches against Agricultural Pests

In this review study, the relationship and effects of pesticides with human and environment have been examined. In addition to the rapidly growing population and urbanization, developing plant biotechnology for the production of agricultural products to meet the needs and an indispensable part of modern agriculture have become pesticides. Pesticides are being used extensively in the world in order to eliminate harmful substances in agricultural areas and to obtain quality products. As a result of unconscious pesticide use, human, air, water, soil and wild life are affected adversely, resistance is formed in target living beings, natural balance and natural balance are seen to be deteriorated by killing natural life and beneficial beings. Despite all the adversities brought by the pesticides, the use of different methods to combat the pests, the consciousness of the public on this issue and the increasing use of biopesticides which are very important are showing promising developments. It is also a very important development to see biopesticides begin to take up chemical pesticides in developed countries, especially in developing countries.

Pesticide Interactions: Mechanisms, Benefits, and Risks.

Interactions between pesticides at common molecular targets and detoxification systems often determine their effectiveness and safety. Compounds with the same mode of action or target are candidates for cross resistance and restrictions in their recommended uses. Discovery research is therefore focused on new mechanisms and modes of action. Interactions in detoxification systems also provide cross resistance and synergist and safener mechanisms illustrated with serine hydrolases and inhibitors, cytochrome P450 and insecticide synergists, and glutathione S-transferases and herbicide safeners. Secondary targets are also considered for inhibitors of serine hydrolases, aldehyde dehydrogenases, and transporters. Emphasis is given to the mechanistic aspects of interactions, not the incidence, which depends on potency, exposure, ratios, and timing. The benefits of pesticide interactions are the additional levels of chemical control to achieve desired organismal effects. The risks are the unpredictable interactions of complex interconnected biological systems. However, with care, two can be better than one.

Solvent-dependent binding interactions of the organophosphate pesticide, chlorpyrifos (CPF), and its metabolite, 3,5,6-trichloro-2-pyridinol (TCPy), with Bovine Serum Albumin (BSA): A comparative fluorescence quenching analysis

Analysis of the interaction of pesticides and their metabolites with the cellular proteins has drawn considerable attention in past several years to understand the effect of pesticides on environment and mankind. In this study, we have investigated the binding interaction of Bovine Serum Albumin (BSA) with a widely used organophosphorous insecticide chlorpyrifos (CPF), and its stable metabolite, 3,5,6-trichloro-2-pyridinol (TCPy) to provide a comparative analysis of the two molecules by employing various spectroscopic techniques viz., UV–vis absorption, Circular Dichroism (CD), and Fluorescence spectroscopy. The fluorescence quenching studies of BSA emission in two different solvents viz., water and methanol in presence of CPF and TCPy have led to the revelation of several interesting facts about the pesticide-protein interaction. It has been found that both the molecules cause static quenching of BSA emission as seen from the Stern-Volmer constant (Ksv) irrespective of the solvent used for the analysis. While TCPy is a stronger quencher in water, it exhibits comparable quenching capacity with CPF in methanol. The solvent dependent differential binding interaction of the two molecules finally indicates possibility of diverse bio-distribution of the pesticides within human body. The UV–vis and CD spectra of BSA in presence of the test molecules have unravelled that the molecules formed ground state complex that are highly reversible in nature and have minimal effect on the protein secondary structure. Furthermore it is also understood that structural changes of BSA in presence of CPF is significantly higher compared to that in presence of TCPY.

Revisiting the Environmental Interactions of Pesticides

As population increases, the demand for safe and nutritious food, safe water and air quality increases. The emergence of pesticides has played as an essential role in preventing pests from destroying various valued properties in our homes, offices and farmlands. The usage of pesticides has a role to play in the achievement of a sustainable developed earth. The earth today needs to be sustainable for future generations, and hence the need to develop it sustainably. The sustainable development aspect consist of the social, economic and environment. The benefits of pesticide in these recent years seem to have been overlooked since the risks associated with its exposure to our health and environment is fatal. As a result, this study revisits the benefits (primary and secondary) of pesticides to man, its economy and environment. The negative effects of pesticide residue exposure in the environment: the atmosphere, soil and water, and how pesticide exposures affect the human system are revisited. Despite the evidence of the adverse effects of the use of pesticides, its usage has increased in the past decades. This paper ascertains the reasons behind the use of pesticides and propose some recommendations to reduce the effects of its exposure.