Different Classes Of Pesticides Research Articles

Effects of acute insecticide exposure on neuronal activity in vitro in rat cortical cultures

Exposure to pesticides, such as carbamates, organophosphates, organochlorines and pyrethroids, has been linked to various health problems, including neurotoxicity. Although most in vivo studies use only male rodents, some studies have shown in vivo sex-specific effects after acute exposure. Since in vivo studies are costly and require a large number of animals, in vitro assays that take sex-specific effects into account are urgently needed. We therefore assessed the acute effects of exposure to different carbamates (methomyl, aldicarb and carbaryl), organophosphates (chlorpyrifos (CPF), chlorpyrifos-oxon (CPO) and 3,5,6-trichloropyridinol), organochlorines (endosulfan, dieldrin and lindane) and pyrethroids (permethrin, alpha-cypermethrin and 3-phenoxy-benzoic acid (3-PBA)) on neuronal network function in sex-separated rat primary cortical cultures using micro-electrode array (MEA) recordings. Our results indicate that exposure to the carbamate carbaryl and the organophosphates CPF and CPO decreased neuronal activity, with CPO being the most potent. Notably, (network) burst patterns differed between CPF and CPO, with CPO inducing fewer, but more intense (network) bursts. Exposure to low micromolar levels of endosulfan induced a hyperexcitation, most likely due to the antagonistic effects on GABA receptors. Interestingly, females were more sensitive to endosulfan than males. Exposure to dieldrin and lindane also increased neuronal activity, albeit less than endosulfan and without sex-specific effects. Exposure to type I pyrethroid permethrin increased neuronal activity, while exposure to type II pyrethroid alpha-cypermethrin strongly decreased neuronal activity. The increase seen after permethrin exposure was more pronounced in males than in females. Together, these results show that acute exposure to different classes of pesticides exerts differential effects on neuronal activity. Moreover, it shows that MEA recordings are suited to detect sex-specific neurotoxic effects in vitro.

Pesticides in surface water of the Ondas river watershed, western Bahia, Brazil: Spatial-seasonal distribution and risk assessment

This study investigated the occurrence and seasonal distribution of different classes of pesticides in surface waters of the Ondas River Watershed, as well as potential risks to the aquatic health and human water consumption in the western region of Bahia state, Brazil. Two gas chromatography-mass spectrometry analytical methods were applied to monitor 34 pesticides in water samples collected during both the dry and rainy seasons at 17 sites. Upon individual analysis, only γ-HCH, methoxychlor, demeton-S, methyl parathion, fenitrothion, chlorpyrifos, and azoxystrobin exhibited statistically significant differences between seasons. During rainy season, concentration medians of residues were higher for γ-HCH (74.7 ng L−1), methoxychlor (25.1 ng L−1), and azoxystrobin (47.2 ng L−1), potentially linked to historical contamination or illegal use. Conversely, pesticides like methyl parathion, fenitrothion, and chlorpyrifos, belonging to the organophosphate class, showed higher concentration medians in the dry period, measuring 75.1, 5.50, and 10.8 ng L−1, respectively, probably due to region crop activities. The risk quotient (RQ) assessment for aquatic life indicated that 59.0% of the samples in the dry season and 76.0% in the rainy season had RQ values greater than one, signifying a critical scenario for species conservation. Regarding human consumption, elevated risks were observed for heptachlor in both sampling periods and for azoxystrobin during the rainy season, surpassing RQ levels above 1, indicating danger in untreated water ingestion. Additionally, 24.0% and 53.0% of the samples in the dry and rainy seasons, respectively, contained at least one pesticide exceeding the EU resolution limit (100 ng L−1). Therefore, considering this information, implementing mitigation measures to avoid the river's contamination becomes imperative.

An adverse outcome pathway-based approach to assess the neurotoxicity by combined exposure to current-use pesticides

Exposure to multiple pesticides in daily life has become an important public health concern. However, the combined effects of pesticide mixtures have not been fully elucidated by the conventional toxicological testing used for individual chemicals. Grouping of chemicals by mode of action using common key events (KEs) in the adverse outcome pathway (AOP) as endpoints could be applied for efficient risk assessment of combined exposure to multiple chemicals. The purpose of this study was to investigate whether exposure to multiple pesticides has synergistic neurotoxic effects on mammalian nervous systems. According to the AOP-based approach, we evaluated the effects of 10 current-use pesticides (4 neonicotinoids, 4 pyrethroids and 2 phenylpyrazoles) on the common KEs in AOPs for neurotoxicity, such as KEs involving mitochondrial and proteolytic functions, in a mammalian neuronal cell model. Our data showed that several pyrethroids and phenylpyrazoles partly shared the effects on several common KEs, including decreases in mitochondrial membrane potential and proteasome activity and increases in autophagy activity. Furthermore, we also found that combined exposure to a type-I pyrethroid permethrin or a type-II pyrethroid deltamethrin and the phenylpyrazole fipronil decreased the cell viability and the benchmark doses much more than either single exposure, indicating that the pair exhibited synergistic effects, since the combination indexes were less than 1. These findings revealed that novel pairs of different classes of pesticides with similar effects on common KEs exhibited synergistic neurotoxicity and provide new insights into the risk assessment of combined exposure to multiple chemicals.

Follicular DNA Damage and Pesticide Exposure Among Latinx Children in Rural and Urban Communities

AbstractThe intersectional risks of children in United States immigrant communities include environmental exposures. Pesticide exposures and their biological outcomes are not well characterized in this population group. We assessed pesticide exposure and related these exposures to DNA double-strand breaks (DSBs) in Latinx children from rural, farmworker families (FW; N = 30) and from urban, non-farmworker families (NFW; N = 15) living in North Carolina. DSBs were quantified in hair follicular cells by immunostaining of 53BP1, and exposure to 72 pesticides and pesticide degradation products were determined using silicone wristbands. Cholinesterase activity was measured in blood samples. DSB frequencies were higher in FW compared to NFW children. Seasonal effects were detected in the FW group, with highest DNA damage levels in April–June and lowest levels in October–November. Acetylcholinesterase depression had the same seasonality and correlated with follicular DNA damage. Organophosphate pesticides were more frequently detected in FW than in NFW children. Participants with organophosphate detections had increased follicular DNA damage compared to participants without organophosphate detection. Follicular DNA damage did not correlate with organochlorine or pyrethroid detections and was not associated with the total number of pesticides detected in the wristbands. These results point to rural disparities in pesticide exposures and their outcomes in children from vulnerable immigrant communities. They suggest that among the different classes of pesticides, organophosphates have the strongest genotoxic effects. Assessing pesticide exposures and their consequences at the individual level is key to environmental surveillance programs. To this end, the minimally invasive combined approach used here is particularly well suited for children.

Insights Into the Application of Polyaniline-Based Composites in Environmental Engineering

Environmental management demands innovative techniques for its protection and treatment. The essential agreement of the modern world is to overcome every issue in a sustainable way. The two major financial problems in this area are water pollution and material corrosion. Persistent, organic compounds such as pesticides have devastating effects on the water ecosystem. This problem can be solved by applying advanced treatment processes (ATPs) like membrane separation and photocatalysis. Additionally, the corrosion of metal materials needs to be prevented to preserve natural resources and reduce environmental concerns. Therefore, researchers are trying to develop tunable, multifunctional materials with broad applications. Employed materials in these operations must fulfill high criteria, like durability, stability, and chemical and optical activity, to make specified processes efficient and viable. Electroconductive polymers (ECPs) can meet the aforementioned standards. The most used ECP is polyaniline (PANI), due to its catalytic and electrochemical performances. These two properties are beneficial for both water purification and anticorrosion applications. The objectives of the paper are to represent various PANI-based composites utilized in the removal of different classes of pesticides during wastewater treatment by adsorption or photocatalytic degradation. Further corrosion inhibition, utilizing PANI-based inhibitors, will be discussed as well.

Multiresidue method for determination of pesticides in papaya using modified QuEChERS and UHPLC-MS/MS

ABSTRACT Papaya is the fourth most consumed fruit in Brazil and the third most exported fruit by the country. Considering that pesticides are frequently used in agriculture to increase production this work aimed to establish a method for the multiresidue determination of pesticides in papaya using the QuEChERS method and analysis by ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS). The parameters that influence the extraction efficiency were studied and, after finding the best extraction conditions, the method was validated. The analysis by UHPLC-MS/MS allowed the determination of analytes with high selectivity and detectability. The main modification of the original QuEChERS method was the use of the polymeric sorbent Strata SDB-L in the clean-up step by dispersive solid-phase extraction. The method was validated for 110 compounds and presented adequate values of accuracy, with recoveries between 70 and 120%, and precision, with RSD<20%. The method limits of quantification ranged from 5 to 10 µg kg−1 and detection limits from 1.5 to 3 µg kg−1. The validated method was used for the determination of pesticides in commercial papaya samples, and 17 pesticides of different classes were found, including 5 pesticides not authorised in Brazil for papaya. Considering the results obtained, the use of the proposed method proved to be fast and efficient for the multiresidue determination of pesticides in papaya in routine analysis.

Dynamic light scattering and zeta-potential as a tool for understanding the mechanism of pesticides binding toward individual components of transition metal nanoparticles and graphene oxide hybrids

Pesticides present in their commercial formulations are studied for their preferable binding toward carbon-based graphene oxide (GO) or transition metal nanoparticles (Fe, Co, Ni, and Cu), present as hybrids. This simple study also reveals the mechanism of interaction of few selected different classes of pesticides, namely, λ-cyhalothrin, imidacloprid, and metsulfuron-methyl toward these hybrids. Individually, to study this comparative binding when hybrids are not used, the understanding of preferred binding toward any of these selected compounds could be challenging, costly, and time-consuming. Dynamic light scattering (DLS) is used to study the changes observed for hydrodynamic radius and zeta potential for the stability of the resulting products. This simple method can also be extended to identify the binding mechanism for other diverse set of combinations. These studies are supported by binding of GO with nanoparticles in batch adsorption and the best fit using Langmuir and Freundlich isotherms is presented. Moreover, pesticide adsorption toward GO-nanoparticle composites is also evidenced.

Determination of Pesticide Residues in Grapes Consumed in Natura and for Juice and Wine Production by High-Performance Liquid Chromatography with High Resolution Mass Spectrometry (HPLC-HRMS)

The grape is the fifth most consumed fruit around the world with a production of approximately 85 million tons that requires pesticide use; however, some of these compounds may damage to the environment, as well as have implications for human and animal health. Therefore, the present work aims to evaluate the pesticide residues present in grapes of different varieties for in natura consumption as well as for production of wine and juice. As a result, the methodology was validated having limits of quantification ranging from 14.86 (for chlorantraniliprole) to 308.01 µg L−1 (for etofenprox), recovery values between 82 and 119%, and relative standard deviations less than 20%. Thus, the method was applied to 10 real samples produced in south Brazil, targeting 92 pesticides of different classes by high-performance liquid chromatography coupled to high resolution mass spectrometry (HPLC-HRMS). Approximately 80% of the samples have residues of at least one compound, including 6 pesticides not approved for grape cultivation: atrazine, carbaryl, carbendazim, etoxazole, malathion, and simazine. Fenarimol is allowed to be used in this culture in Brazil; however, it was present in a concentration higher than its maximum residue level (MRL) in 57% of the samples. Thus, in this work, we present the application of a valid method by HLC-HRMS for grapes. These results show that, regardless of the variety and purpose of the grapes, many pesticides are present in this fruit, requiring greater control by farmers as well as supervisory bodies because the toxicological effects of these compounds in high concentrations have already been demonstrated in both consumers and farmers who have been directly exposed.

An integrative review on the analysis of pesticide multiresidues in sweet pepper samples using the QuEChERS method and chromatographic techniques

Since foods are complex matrices that contain pesticides of different classes, multiresidue sample preparation methods such as QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) are used and modified to obtain more accurate and sensitive results. This work was developed through an integrative review in the journal databases Capes, Science Direct, Scielo, and Scientia Chromatographic, from 2011 to 2021, to answer the following question: “What is the most efficient and advantageous sample preparation method for the determination of multiresidue pesticides of interest in sweet pepper samples, when chromatographic techniques are used for detection?” The sweet pepper was chosen because the Pesticide Residue Analysis in Food Program (PARA) suggests that it is the sample with the highest percentage of irregularities related to active ingredients not allowed or above the Maximum Residue Limit (MRL). A total of 391 articles were found, 11 of which met the inclusion criteria established. Several analyses were studied. The organophosphates were the most studied class of pesticide, with seven articles. In addition, there was a predominance of nonpolar analytes (log Kow &gt; 1). The use of different extracting solvents, such as methanol, acetonitrile, ethyl acetate, and acetone, was observed, with acetonitrile presenting the best analytical parameters in most cases. The use of different sorbents such as secondary and primary secondary amine (PSA), ocatadecyllane (C18), graphite carbon (GCB), and carbon black was noted, as well. The authors highlight the difficulties in the analysis when the matrix effect is significant (except for fensulfothion, tensulfothion, flonicamid, and its metabolite TFNA-AM) and the degradation of analytes through the analysis process (flonicamid, captan, folpet, thiophanate methyl and benomyl). Finally, the statistical test Analysis of Variance (ANOVA) was used to identify if there was a significant difference between the different methods used for the same analysis or when the same method used for the different analytes.

Ozonation for remediation of pesticide-contaminated soils at field scale

This work is the first ever study under field conditions for the removal of different classes of pesticides from soil using ozonation as a remediation technique. Initial assays were conducted with three different soil matrices to assess the effectiveness of the methodology under lab conditions. Field scale experiments were carried out on plots located in a greenhouse during the winter of 2020. The polluted soil was exposed to different treatments to test the effect of the mode of ozone application on pesticide degradation (S: polyethylene film covering, SOS: polyethylene film + surface ozone application, SOD: polyethylene film + deep application, SODS: polyethylene film + dual application, and C: no treatment). Ozonation impact was also assessed by variations on physical–chemical characteristics of the soil. Higher degradation was detected in ozonized soils, particularly in the SODS treatment, where ozone was dually applied on the surface and deep. During monitoring of remediation experiments, 15 of the main transformation products (TPs) were found. The results suggest that ozonation has favourable prospects to be considered a credible alternative technology for remediation of pesticide polluted soils.

The Complex Role of Lactic Acid Bacteria in Food Detoxification.

Toxic ingredients in food can lead to serious food-related diseases. Such compounds are bacterial toxins (Shiga-toxin, listeriolysin, Botulinum toxin), mycotoxins (aflatoxin, ochratoxin, zearalenone, fumonisin), pesticides of different classes (organochlorine, organophosphate, synthetic pyrethroids), heavy metals, and natural antinutrients such as phytates, oxalates, and cyanide-generating glycosides. The generally regarded safe (GRAS) status and long history of lactic acid bacteria (LAB) as essential ingredients of fermented foods and probiotics make them a major biological tool against a great variety of food-related toxins. This state-of-the-art review aims to summarize and discuss the data revealing the involvement of LAB in the detoxification of foods from hazardous agents of microbial and chemical nature. It is focused on the specific properties that allow LAB to counteract toxins and destroy them, as well as on the mechanisms of microbial antagonism toward toxigenic producers. Toxins of microbial origin are either adsorbed or degraded, toxic chemicals are hydrolyzed and then used as a carbon source, while heavy metals are bound and accumulated. Based on these comprehensive data, the prospects for developing new combinations of probiotic starters for food detoxification are considered.

Perinatal exposure to pesticides alters synaptic plasticity signaling and induces behavioral deficits associated with neurodevelopmental disorders

Increasing evidence from animal and epidemiological studies indicates that perinatal exposure to pesticides cause developmental neurotoxicity and may increase the risk for psychiatric disorders such as autism and intellectual disability. However, the underlying pathogenic mechanisms remain largely elusive. This work was aimed at testing the hypothesis that developmental exposure to different classes of pesticides hijacks intracellular neuronal signaling contributing to synaptic and behavioral alterations associated with neurodevelopmental disorders (NDD). Low concentrations of organochlorine (dieldrin, endosulfan, and chlordane) and organophosphate (chlorpyrifos and its oxon metabolite) pesticides were chronically dosed ex vivo (organotypic rat hippocampal slices) or in vivo (perinatal exposure in rats), and then biochemical, electrophysiological, behavioral, and proteomic studies were performed. All the pesticides tested caused prolonged activation of MAPK/ERK pathway in a concentration-dependent manner. Additionally, some of them impaired metabotropic glutamate receptor-dependent long-term depression (mGluR-LTD). In the case of the pesticide chlordane, the effect was attributed to chronic modulation of MAPK/ERK signaling. These synaptic alterations were reproduced following developmental in vivo exposure to chlordane and chlorpyrifos-oxon, and were also associated with prototypical behavioral phenotypes of NDD, including impaired motor development, increased anxiety, and social and memory deficits. Lastly, proteomic analysis revealed that these pesticides differentially regulate the expression of proteins in the hippocampus with pivotal roles in brain development and synaptic signaling, some of which are associated with NDD. Based on these results, we propose a novel mechanism of synaptic dysfunction, involving chronic overactivation of MAPK and impaired mGluR-LTD, shared by different pesticides which may have important implications for NDD.Graphical abstract

COMPARATIVE HYGIENIC ASSESSMENT AND ANALYSIS OF THE RANGES AND SCOPE OFF PESTICIDES IN DIFFERENT COUNTRIES

Relevance. The task of maximizing the resource potential of agriculture is facing all countries of the world, including Ukraine. Pesticides allow farms to increase their efficiency, increase yields and reduce losses from harmful factors.&#x0D; Objective: analysis and hygienic assessment of the quantitative use and volume of use of different classes of pesticides in the world.&#x0D; Materials and methods. The object of our research was the range and scope of pesticides used in our countries; factors influencing and the use of different classes of pesticides.&#x0D; Results. Ukraine ranks first in Europe in terms of sown areas among the countries we study – 72% of the total area of the state. Jamaica has the largest number of drugs, their number is 3791 pesticides. In the structure of the range of chemical plant protection products Australia, Canada and Ukraine include 3248 pesticides, 3025 pesticides and 893 pesticides, respectively. The highest rate of pesticide use in the United States is 373 kg per 1 hectare of field, in Ukraine it is only 2 kg per 1 hectare of sown area (the last place among the countries we studied). New generations of plant growth regulators are being introduced into world agriculture, which will increase the gross harvest of the main food crops by 15-20 %. The predominant producers of chemical plant protection products (according to our estimates in 2018) in Ukraine are China – 42%, own production – 12%, Switzerland – 8%, Germany – 7% and others.&#x0D; Conclusion. The use of plant chemicals is an integral part of modern world agriculture. The volume, quantity and range of pesticides in the countries of the world we study depend on many factors. Among them: territorial location, climatic and weather conditions, level of economic development, etc.

Targeted Multiresidue Method for the Analysis of Different Classes of Pesticides in Agro-Food Industrial Sludge by Liquid Chromatography Tandem Mass Spectrometry.

Sludge generated after washing of fruits and vegetables during agro-food processes is a complex matrix and selective methods for the identification and quantification of pesticides’ residues are necessary in order to achieve a sustainable and effective management of the total sewage. The present work describes the development and validation of a reliable, simple and fast analytical method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the determination of 47 pesticides of different chemical classes, including organosphosphates, pyrethroids, neonicotinoids, triazoles and others, in sludge samples after QuEChERS sample preparation. The necessity of the individual steps of QuEChERS was investigated and the LC-ESI-MS/MS conditions were optimized to achieve maximum sensitivity of the target analytes. The method limits of detection (LODs) ranged between 0.0005 mg/kg (imidacloprid) and 0.05 mg/kg (beta cyfluthrin). The recoveries ranged between 71–120% and the repeatability of the method was ≤25% expressed as relative standard deviation. The method was applied to sludge samples generated after washing of fruits in an agro-fruit-packaging unit in Greece. The results showed the presence of 37 pesticides’ active substances with concentrations ranging from low ppbs, such as fludioxinil (5 μg/kg) up to low ppms such as beta cyfluthrin (3.5 mg/kg) and with their sum concentration reaching up to 19 mg/kg.

Interaction between pesticides applied alone or in mixtures in corn

The objective of this work was to evaluate the selectivity of herbicides applied alone or in tank mix, and also of combinations of different classes of pesticides (fungicides, herbicides and insecticides) on corn. An experiment was installed in the 2017/18 crop to assess herbicide selectivity, and repeated in 2018/19. The second experiment aimed to assess the selectivity of mixtures of different classes of pesticides, and was installed only in 2017/18. The experimental design adopted in the tests was randomized blocks, with four replicates. In each trial, a total of 16 treatments were evaluated, plus a control. At 7, 14 and 21 days after the application of treatments the phytotoxicity to corn was evaluated and the yield components and grain yield were determined. Herbicides caused low levels of injury to the corn plants, with small variations in yield components, and affected crop yield differently. The mixtures of pesticides promoted low phytotoxicity, affected yield components inconsistently and caused changes in corn yield. Although these herbicides and other pesticides are registered for use in corn crops, application alone or in tank mix of certain molecules can cause losses in grain yield.

A meta-analytic review of fish antioxidant defense and biotransformation systems following pesticide exposure

Pesticides reach aquatic ecosystems and interact with various targets in cells of fish and other living organisms. Toxicity originates during the metabolization process, which may produce toxic metabolites or reactive oxygen species (ROS). Ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), catalase (CAT), superoxide dismutase (SOD) activities, and levels of reduced glutathione (GSH) indicate toxicants interacted with drug-metabolizing and antioxidant systems, i.e., they are biomarkers of biotransformation and oxidative stress. We meta-analytically quantified the impact of pesticides on the mean response and variability of these biomarkers. Our goals were to verify (i) the overall effect of pesticides on oxidative stress and biotransformation, and how each biomarker respond to exposure; (ii) how the life stage of fish (juvenile and adult) influence biomarkers variability and mean activity; (iii) to what extent fish sex (male, female or mixed-sex groups) modify pesticides toxicity; (iv) how different classes of pesticides, and the combination of their concentration and time of exposure, affect each biomarker. Overall, pesticides induced oxidative stress and the biotransformation system. Regardless of life stage, EROD mean activity increased significantly. In exposed juveniles, CAT and GST variability decreased and increased, respectively. CAT mean activity was higher in females, while EROD and GST activities increased in males after pesticide exposure. Organophosphorus (OPs) and organochlorine insecticides, along with imidazole and triazole fungicides, affected biomarkers the most, however the combined effect of concentration and time of exposure of OPs was not detected. Notably, imidazoles and triazoles classes increased EROD by more than 100%. Additionally, we identified research gaps, such as the lack of effect estimates of relevant pesticides on EROD (e.g., pyrethroids and neonicotinoids) and the small number of studies evaluating GSH on female fish. Future researchers may use these gaps as a guide towards enhanced experimental designs and, consequently, a better understanding of pesticide toxic effects on fish.

Assessment of Ecological Risk and Environmental Behavior of Pesticides in Environmental Compartments of the Formoso River in Tocantins, Brazil.

Anthropogenic interference the ecosystem unavoidably changes the physical and biological environment. The biodiversity of the Amazon region has been threatened by increased agricultural production and pesticide use. Considering that monitoring pesticides in environments close to their application is one of the ways to preserve the ecosystem, this study investigated the levels of pesticide residues in different environmental compartments (soil, sediment, and water samples). Thirty-one active ingredients of pesticides of different classes were analyzed by UHPLC-MS/MS. For this purpose, we performed quarterly collections in dry and rainy seasons in the region, which helped to evaluate the impact of pesticides on the biodiversity of the study site. Sampling points were the river banks in the area of an agricultural project in Formoso do Araguaia city, Tocantins State. After analysis, we detected the following substances in the water matrix: clomazone, fluazifop-p-butyl, flutolanil, metsulfuron-methyl, propanil, and imidacloprid. Nevertheless, we did not detect any active ingredient in sediment and soil matrices. The active ingredient clomazone was present in all points in the trials, with concentrations reaching up to 0.538μgL-1. These substances have potential for groundwater contamination. Even at low concentrations in the aquatic ecosystem, these substances can damage human populations and wildlife species, given their toxicological classification. Thus, the study showed an environmental risk of bioaccumulation and/or biomagnification in the region, which may affect environmental biodiversity as well as human health.

On the possibility of evaluative prediction of the extraction of organic substances of complex structure using the method of group increments

The distribution of pesticides of different classes (amides, anilinopyrimidines, benzene derivatives, benzoylphenylureas, benzenesulfonates, hydrazides, dinitroanilines, carbamates, pyretroids, pyrimidines, tetrazines, triazoles, pheny lureas, organophosphorus compounds, esters of carboxylic acids) was studied at 20 ± 1 °C in the extraction systems of hexane–water, hexane–acetonitrile, hexane– acetonitrile and water mixture that are most often used in analytical chemistry of pesticides. The distribution constants P of pesticides and the increments of logarithms of the distribution constants If of their functional groups between the hydrocarbon and polar phases are calculated. Two main methods for evaluative prediction of lg P of pesticides are proposed and approved – substitutive method based on the calculation of lg P by replacing the substituents in the base molecule and the method of absolute addition of increments. The possibilities of the both methods are illustrated. The reasons for the deviations of the experimental values from the calculated ones are discussed. The influence of the nature and composition of the polar phase on the magnitudes of the observed deviations is estimated. In particular, they decrease dramatically with an increase in the acetonitrile content in the polar phase. Averaged values of correction to the calculated values of lg P are introduced. In most cases, they allow predicting lg P of pesticides with a deviation of not more than 0.5–1.0 from the calculated one.

HYGIENIC ASSESSMENT OF CHANGES IN THE ASSORTMENT AND RANGES OF APPLICATION OF PESTICIDES IN THE AGRICULTURE OF UKRAINE FROM 2015 TO 2019

Relevance. Ukraine actively exports its agricultural products to the markets of Europe and the world. The growth rate of agricultural exports from Ukraine to the EU in May 2019 was 49.9%.&#x0D; Objective was to analyze and hygienically evaluate changes in the assortment and ranges of pesticide application in Ukrainian agriculture over the last 5 years (from 2015 to 2019).&#x0D; Materials and methods. The object of our research was changes in the assortment and ranges of pesticide application in Ukrainian agriculture from 2015 to 2019. Growth and growth rates were calculated.&#x0D; Results. Herbicides are leaders among the pesticides authorized for use in Ukraine: in 2019 their fraction was 56 % of the total (321 formulations). The following in number are fungicides: in 2019 – 25 % (147 formulations); and in third place are insecticides and acaricides: 19 % (107 formulations).&#x0D; Most of all classes’ pesticides are monoformulations. Their growth rate from 2015 to 2019 was 93 %, increasing rate - 52%. In second place - combined formulations with two active substances: their number during 2015-2019 increased by 42%. For pesticides with three active substances, the growth rate from 2015 to 2019 was 145%. Also in 2017 there were herbicide formulations with four active substances, but their number is insignificant: in 2017 – 2, in 2019 – 3 formulations.&#x0D; Conclusion. It was found that in the period from 2015 to 2019, the increase of all chemical plant protection products was 47%. The tendency towards an increase in different classes of pesticides does not change significantly every year and the leaders among them are herbicides, second place is occupied by fungicides and third – by insecticides and acaricides. Pesticides with one active substance (monoformulations) predominate.

Pesticides With Potential Thyroid Hormone-Disrupting Effects: A Review of Recent Data.

Plant Protection Products, more commonly referred to as pesticides and biocides, are used to control a wide range of yield-reducing pests including insects, fungi, nematodes, and weeds. Concern has been raised that some pesticides may act as endocrine disrupting chemicals (EDCs) with the potential to interfere with the hormone systems of non-target invertebrates and vertebrates, including humans. EDCs act at low doses and particularly vulnerable periods of exposure include pre- and perinatal development. Of critical concern is the number of pesticides with the potential to interfere with the developing nervous system and brain, notably with thyroid hormone signaling. Across vertebrates, thyroid hormone orchestrates metamorphosis, brain development, and metabolism. Pesticide action on thyroid homeostasis can involve interference with TH production and its control, displacement from distributor proteins and liver metabolism. Here we focused on thyroid endpoints for each of the different classes of pesticides reviewing epidemiological and experimental studies carried out both in in vivo and in vitro. We conclude first, that many pesticides were placed on the market with insufficient testing, other than acute or chronic toxicity, and second, that thyroid-specific endpoints for neurodevelopmental effects and mixture assessment are largely absent from regulatory directives.