Pesticide Concentrations Research Articles

Intensive short-term sampling with long-term consequences: characterizing pollutant transport with implications for developing monitoring.

Riverine sampling of pollutants is commonly used to understand pollutants' transport pathways, relationships with hydrology, and overall presence in a waterbody. However, temporal gaps between sample collection introduce errors to these efforts, and guidance prescribing sampling frequency remains sparse. The magnitude of error often depends on a contaminant's transport mechanisms and local hydrologic conditions, making the creation of comprehensive sampling guidance difficult. This study analyzed a unique dataset that measured 18 analytes, including pesticides, nutrients, and pathogens, in three Iowa rivers for 90 consecutive days (May 4-August 1, 2000). This dataset provided a novel opportunity to relate pollutants to local hydrology and quantify errors associated with recurring sampling. Pesticide concentrations followed the spring flush phenomenon, where values were greatest during high streamflow in May and June but often depleted by July. Fecal coliform and total phosphorus (TP) also coincided with high flow, but unlike pesticides, their concentrations never diminished. Nitrate exhibited more complex behavior; concentrations were diluted during high flows and then increased as streamflow receded. Autocorrelations were significant for nitrate and atrazine in larger rivers but negligible for fecal coliform and TP. Loads were calculated for four pollutants with minimal non-detects (atrazine, fecal coliform, nitrate, and TP). We simulated intermittent sampling by selecting evenly spaced subsets of measured values to estimate loads, which were compared to the loads calculated using every daily sample to quantify error. This method typically overestimated nitrate loads but underestimated other pollutants, and errors often decreased in larger watersheds. Nitrate generally had the lowest error, while fecal coliform had the highest. We used these results to approximate the sampling frequency needed to bind errors within a certain threshold.

Landscape and local factors drive pesticide distribution in perennial agroecosystems

Abstract Pesticides constitute a major threat to biodiversity, but our understanding of the complex interactions between local and landscape factors influencing their distribution in agroecosystems remains limited. We conducted a pioneering study where we screened spiders, rodents, plants and soils for multiple pesticide residues in perennial crops (orchards and vineyards) managed under organic (N = 8) and integrated pest management (N = 8) systems. We then quantified the proportional representation of major habitat types in surrounding landscapes. Additionally, we conducted interviews with farmers to gain precise insights into pesticide applications. We expected that landscape factors would be more important for mobile entities (i.e. spiders and rodents), while management type would be relatively more important for the sedentary entities (i.e. soils and plants). We detected various pesticides within studied crop types, including several forbidden in the European Union. We found that pesticide distribution in spiders was influenced by the proportion of semi‐natural habitats in the landscape, with pesticide concentration decreasing as the proportion of semi‐natural habitats increased. Additionally, we observed that the spectrum of pesticides in spiders increased with the dominance of web‐building spiders. In contrast, pesticide levels in rodents were not affected by either landscape composition or local management type. For plants, pesticide distribution was affected by the proportion of forests and shrublands and, to some extent, by local management practices. In the case of soil, pesticide distribution was primarily determined by local management. This study marks an effort in demonstrating that both local and landscape factors play crucial roles in shaping pesticide distribution within perennial crops. Importantly, the relative importance of these factors varied across the four matrices investigated. Synthesis and applications: To comprehend the factors that determine pesticide distribution in crops, it is crucial to monitor diverse ecosystem components rather than focusing on a few model species. This approach underscores the necessity for ecologically sensitive management at landscape scale. Such management should involve the preservation and enhancement of (semi)natural habitats around crops. These combined insights can form the foundation for conservation and management initiatives aimed at mitigating the impact of pesticides on biodiversity within crops.

Spatiotemporal distribution of organochlorine pesticides in the upper La Antigua watershed, Veracruz Mexico

Even though the use of organochlorine pesticides has been prohibited since the last century their presence is still being recorded around the world. In the upper La Antigua watershed, Veracruz, Mexico we have reported concentrations of these contaminants in different compartments of the riverine ecosystems. This is of relevance due to their potential disruptive endocrine effect on the vertebrates drinking the water or feeding in the riverine area. In this study we evaluated concentrations of organochlorine pesticides (OCPs) in streams running throughout mountain cloud forest and two different types of land use, pasture lands and coffee plantations. Water and periphyton samples were collected during the wet and the dry seasons from streams located in independent micro-basins. Spatial explicit analyzes show that the concentrations measured are independent of the distribution of the streams in the geographical area sampled. However seasonal differences were found during the dry season in the water and during the rainy season in periphyton. While OCPs in water support the idea that micro-basins can be used as independent monitoring units, OCPs in periphyton can be indicators of the effect of different land use. Some concentrations of all the OCPs registered had values above the limits for tap water.

The impact of landscape structure on pesticide exposure to honey bees

Pesticides may have serious negative impacts on bee populations. The pesticide exposure of bees could depend on the surrounding landscapes in which they forage. In this study, we assess pesticide exposure across various land-use categories, while targeting the Japanese honey bee, Apis cerana japonica, a native subspecies of the eastern honey bee. In a project involving public participation, we measured the concentrations of major pesticides in honey and beeswax collected from 175 Japanese honey bee colonies across Japan and quantitatively analyzed the relationships between pesticide presence/absence or pesticide concentration and land-use categories around the colonies. Our findings revealed that the surrounding environment in which bees live strongly influences pesticide residues in beehive materials, whether the pesticides are systemic or not, with a clear trend for each land-use category. Agricultural lands, particularly paddy fields and orchards, and urban areas resulted in higher pesticide exposure, whereas forests presented a lower risk of exposure. To effectively control pesticide exposure levels in bees, it is essential to understand pesticide usage patterns and to develop appropriate regulatory systems in non-agricultural lands, similar to those in agricultural lands.

Unveiling six novel bacterial strains for fipronil and thiobencarb biodegradation: efficacy, metabolic pathways, and bioaugmentation potential in paddy soil.

Soil bacteria offer a promising approach to bioremediate pesticide contamination in agricultural ecosystems. This study investigated the potential of bacteria isolated from rice paddy soil for bioremediating fipronil and thiobencarb, common agricultural pesticides. Bacterial isolates capable of degrading fipronil and thiobencarb were enriched in a mineral salt medium. A response surface methodology with a Box-Behnken design was utilized to optimize pesticide degradation with the isolated bacteria. Bioaugmentation tests were performed in paddy soils with varying conditions. Six strains, including single isolates and their mixture, efficiently degraded these pesticides at high concentrations (up to 800 µg/mL). Enterobacter sp., Brucella sp. (alone and combined), and a mixture of Stenotrophomonas sp., Bordetella sp., and Citrobacter sp. effectively degraded fipronil and thiobencarb, respectively. Notably, a single Pseudomonas sp. strain degraded a mixture of both pesticides. Optimal degradation conditions were identified as a slightly acidic pH (6-7), moderate pesticide concentrations (20-50 µg/mL), and a specific inoculum size. Bioaugmentation assays in real-world paddy soils (sterile/non-sterile, varying moisture) demonstrated that these bacteria significantly increased degradation rates (up to 14.15-fold for fipronil and 5.13-fold for thiobencarb). The study identifies these novel bacterial strains as promising tools for bioremediation and bioaugmentation strategies to tackle fipronil and thiobencarb contamination in paddy ecosystems.

Gestational organophosphate pesticide exposure and childhood cardiovascular outcomes

IntroductionThe general population is chronically exposed to organophosphate pesticides through various routes including ingestion, hand-to-mouth contact, inhalation, and dermal contact. Exposure to organophosphate pesticides during pregnancy impairs fetal development, but the potential long-term effects of gestational organophosphate pesticide exposure are less well understood. MethodsWe investigated associations between gestational organophosphate pesticide exposure and cardiovascular outcomes in 643 children in the Generation R Study, a prospective pregnancy cohort based in Rotterdam, The Netherlands. Urinary organophosphate pesticide metabolites (dimethyl [∑DMAP], diethyl [∑DEAP], and total dialkyl phosphate [∑DAP] metabolites) were quantified in three urine samples collected from pregnant participants, and their children were followed until age 10 years at which time cardiac magnetic resonance imaging, ultrasonography, blood pressure, and serum biomarkers assessed cardiovascular health. Linear regression models estimated associations (β and 95 % confidence interval [CI]) between a one-interquartile range (IQR) increase in averaged gestational exposure biomarker concentrations and z-scored pediatric cardiovascular outcomes. We investigated effect modification of associations by PON1 genotype. ResultsCarotid intima-media thickness z-score was lower (β: -0.14 [95 % CI: −0.25, −0.02]) and HDL cholesterol z-score was higher (β: 0.14 [95 % CI: 0.02, 0.25]) for increases in ∑DEAP concentrations. Carotid intima-media distensibility z-score was lower (β: -0.08 [95 % CI: −0.19, 0.03]) for increases in ∑DMAP concentrations, and systolic blood pressure z-score was higher (β: 0.10 [95 % CI: −0.01, 0.21]) for increases in ∑DMAP and ∑DAP. Among those with PON1-161CC and PON1-L55MTT genotypes, higher organophosphate pesticide concentrations conferred an excess risk of adverse vascular and glycemic outcomes, respectively. ConclusionsWe observed heterogenous associations between gestational organophosphate pesticide exposure and pediatric cardiovascular health: an anti-atherogenic profile was observed for increases in ∑DEAP concentrations, and impairments in multiple aspects of cardiovascular health was observed for increases in ∑DMAP concentrations. PON1-161 and PON1-L55M single nucleotide polymorphisms modified associations for vascular and glycemic outcomes, respectively.

Evaluation of the effects of two commercial pesticides on Daphnia magna in different feeding environments using morphological and biochemical markers

ABSTRACT In this study, the impact of exposure to a glyphosate-based herbicide (GBH) and a trifloxystrobin-based fungicide (TBF) on Daphnia magna in diverse feeding environments was assessed through the analysis of morphological and biochemical markers. The test organisms selected for analysis were Chlorella vulgaris and D. magna. First, the 48-hour median lethal concentrations (LC50) of GBH and TBF for D. magna were determined to be 253.1 mg/L and 20.7 µg/L, respectively. Secondly, the lethality, length, width, and spin length of D. magna were evaluated following exposure to sublethal pesticide concentrations, selected based on the LC50 values, in different feeding environments. Thirdly, the activities of glutathione S-transferase (GST), glutathione reductase, catalase (CAT), carboxylesterase, and acetylcholinesterase, as well as the levels of reduced glutathione, were measured in D. magna exposed to sublethal pesticide concentrations in different feeding environments. Both pesticides caused an increase in CAT activity, while GBH also caused an increase in GST activity in the unfed and mixed-fed groups. Conversely, it can be concluded that feeding with C. vulgaris reduces oxidative stress and toxic effects since there was a lesser increase in GST and CAT activities in the C. vulgaris-fed group for both pesticides, similar to the lethality.

Atrazine dependence in cultivated fungal communities.

The isolation and study of fungi within specific contexts yield valuable insights into the intricate relationships between fungi and ecosystems. Unlike culture-independent approaches, cultivation methods are advantageous in this context because they provide standardized replicates, specific species isolation, and easy sampling. This study aimed to understand the ecological process using a microcosm system with pesticide concentrations similar to those found in the soil, in contrast to high doses, from the isolation of the enriched community. The atrazine concentrations used were 0.02mg/kg (control treatment), 300ng/kg (treatment 1), and 3000ng/kg (treatment 2), using a 28-day microcosm system. Ultimately, the isolation resulted in 561 fungi classified into 76 morphospecies. The Ascomycota phylum was prevalent, with Purpureocillium, Aspergillus, and Trichoderma being consistently isolated, denoting robust and persistent genera. Diversity analyses showed that the control microcosms displayed more distinct fungal morphospecies, suggesting the influence of atrazine on fungal communities. Treatment 2 (higher atrazine concentration) showed a structure comparable to that of the control, whereas treatment 1 (lower atrazine concentration) differed significantly, indicating that atrazine concentration impacted community variance. Higher atrazine addition subtly altered ligninolytic fungal community dynamics, implying its potential for pesticide degradation. Finally, variations in atrazine concentrations triggered diverse community responses over time, shedding light on fungal resilience and adaptive strategies against pesticides.

First evidence of age-dependent decreases in non-persistent pesticide mixtures in nestlings of a farmland raptor

Intensive use of synthetic pesticides in conventional agriculture may harm non-target organisms through sublethal effects on life-history traits. Farmland birds are exposed throughout their life cycle, but the fate of non-persistent pesticide mixtures in wild birds remains unknown. In this study, we investigated changes in pesticide contamination levels in Montagu’s harrier (Circus pygargus) nestlings during their growth. In total, 35 chicks were sampled twice during the rearing period, and blood was tested for 116 pesticides to assess pesticide load through two proxies; the number of pesticides detected and the sum of pesticide concentrations. Body mass and tarsus length were also measured to estimate body condition. Across the two sampling times, nine herbicides, five insecticides and four fungicides were detected. Contamination levels decreased significantly with nestling age irrespective of sampling date, and there was no relationship between pesticide load and body condition. Moreover, concentrations of chlorpyrifos-methyl, fenpropidin, metamitron, picloram and S-metolachlor, all detected throughout the rearing period, were unrelated to any of the explanatory variables. However, ethofumesate concentrations decreased significantly with chick age. This study provides the first evidence that non-persistent pesticide mixtures can decrease with age in wild nestlings. This has implications for understanding how chicks are contaminated and provides new insights on pesticide fate within organisms.

Screening and quantification of pesticides in wetland water, ice, sediment and soil: Occurrence, transport and risk assessment

Current researches on pesticides in wetlands are limited in terms of screening and quantification of many types of pesticides. Understanding the spatial and temporal dynamics, distribution patterns, and environmental risks of pesticides in multiple media is important for wetland ecological conservation. In this study, 222 pesticides were determined in multimedia samples collected simultaneously from the Songhua Wetland during four seasons. Concentrations of target pesticides in water, ice, sediment and soil ranged from 94.1 to 7445 ng/L, 62.6–953 ng/L, 0.82–50.2 ng/g dw, and 4.32–146 ng/g dw. Large spatial differences (p < 0.05) in pesticide concentrations in ice were found. However, there were no significant differences in the spatial and temporal distribution of pesticides in water, sediment, and soil (p > 0.05), suggesting that there were no correlation between the spatial and temporal use of pesticides. The dynamic exchange of pesticides between water-ice indicated that most pesticides were more enriched in water. However, there were still some pesticides (Dichlorvos and Biphenyl) that showed a stronger tendency to transfer from water to ice. Sediment-water exchange suggested that sediment is a source of secondary releases of most pesticides in wetland ecology, but is a sink for Biphenyl and Oxadiazon. The correlation between concentration ratios and fugacity fraction supported this finding. Most individual pesticides in wetland water and ice had shown low or moderate ecological risk conducted using risk quotient. The cumulative toxic effects of multiple pesticides had a high potential to pose a threat to wetland aquatic organisms.

Assessing Organochlorine Pesticide Behavior in Agricultural Watershed Soil, Water and Sediment: A Dynamic Modeling Approach

ABSTRACT The utilization of pesticides has experienced a substantial rise in order to enhance both the quantity and caliber of the produced goods. Agricultural runoff, a major source of nonpoint pollution, adversely impacts surface water, groundwater, soil and sediment quality in the watershed. Especially, organochlorine pesticides have adverse effects on the environment because of their toxicity, persistence and bioaccumulation. In this study, the presence of organochlorine pesticides (DDTs- dichlorodiphenyltrichloroethane and HCHs- hexachlorocyclohexane) in the environment of the dryland agricultural watershed, was determined. For this purpose, soil, sediment and water samples from the landscape of pond were collected. The concentrations of organochlorine pesticides in water, sediment, and soil ranged from 0.0005 to 0.0138 μg/L, 0.03 to 1.02 μg/kg, and 0.54 to 52 μg/kg, respectively. The persistence of these pesticides in soil and sediment poses long-term risks to both terrestrial and aquatic ecosystems. Sediment, as a significant reservoir for these contaminants, can act as a secondary source of pollution, releasing pesticides back into the water column under certain environmental conditions. Similarly, soil contamination not only affects plant health and productivity but also leads to further leaching and runoff into water bodies. The behavior of a toxic substance in water, soil and sediment environment, which is organochlorine pesticide, in a well-mixed lake watershed, was modeled using mass balances in the lake. Statistical analysis, including a paired t-test and calculation of the Nash-Sutcliffe index, confirms the consistency and reliability of the model’s predictions compared to observed data. Simulated concentrations closely matched observed values, and the distribution patterns and trends remained consistent across different months. Moreover, the Risk Quotient (RQ) for DDTs and HCHs is less than 0.1, indicating low ecological risk.

Effect of gamma irradiation on the degradation rate of various pesticides and active ingredients in dandelion

The levels of 37 pesticides in dandelion were analyzed using gas chromatography-tandem mass spectrometry (GC–MS/MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The dandelion samples were treated with different irradiation doses, pH levels, moisture contents, and initial concentrations. Additionally, the respective contents of chicoric, chlorogenic, and caffeic acids in the dandelion samples were determined using high-performance liquid chromatography (HPLC) with DAD detector. The results showed that the pesticide degradation rate was positively correlated with the irradiation dose and negatively correlated with pesticide concentration. The degradation of most pesticides followed first-order kinetics. The pesticide degradation rate initially decreased and subsequently increased with an increase in the pH. Irradiation below 8 kGy had an insignificant effect on the three active ingredients of dandelion. The chicoric acid content decreased with an increase in water content and pH, whereas the caffeic acid content increased.

Assessing the distribution and ecotoxicological risks of organochlorine pesticides in a river-wetland system of the Manipur River basin, India

ABSTRACT The present study aims to evaluate the distribution of organochlorine pesticides in the Loktak Lake and its draining rivers over a spatial and seasonal scale. Organochlorine pesticides including α- HCH, β- HCH, γ- HCH, δ- HCH, Aldrin, 4,4-DDE, Endrin, Endosulfan II, 4,4-DDD, Endrin Aldehyde, Endosulfan sulphate and 4,4-DDT were analysed in the water and sediments adopting gas chromatography and mass spectrometric techniques. The concentration of pesticides recorded the highest concentration of 2271 ng/l in the water samples and 5319 ng/g in sediment samples. In water samples, Endosulfan II, Endrin and γ- HCH were present at the higher concentrations, whereas α-BHC was recorded at the lowest at 0.78 ng/l. In sediment samples, 4, 4-DDT recorded the highest concentration, followed by 4,4-DDD and Endosulfan II. Human health risk assessment based on water consumption shows higher risk potential from five pesticides. Pesticides in the region may pose a threat to the wetland comprising vital flora and fauna of the biodiversity hotspot. The bacterial population was more or less related to the pesticide concentration, with a lower population at less contaminated sites.

Modelling pesticide concentrations in Japanese paddy fields using the RICEWQ model

Increasing concerns about plant protection products in surface waters have highlighted the importance of pesticide monitoring and modelling, both nowadays integral components of the pesticide registration process. The Rice Water Quality (RICEWQ) model predicts the fate and transport of pesticides under various paddy environmental conditions. The model has been used widely for regulatory purpose in the U.S., while its use in Europe has been limited to regulatory submissions, despite multiple recommendations to adopt RICEWQ as a high tier assessment model for regulatory purposes. The applicability of the RICEWQ model under Japanese agricultural conditions remains unexplored. This study leverages field experimental data to evaluate the RICEWQ model's capability to simulate daily concentrations of two herbicides, mefenacet and pretilachlor, in paddy water and paddy soil in Japan.The RICEWQ model provided a reasonable level of performance for predicting the fate and transport of the two herbicides by ensuring that the simulated daily water balance corresponded with field observations and with minor pesticide-specific calibration. To further improve the performance of the simulations, we implemented a straightforward calibration framework. Calibrating the RICEWQ model improved the accuracy of all simulations; for both herbicides and in both paddy water and paddy soil compartments, the lowest Nash-Sutcliffe efficiency achieved was 0.725, demonstrating excellent performance. However, the RICEWQ model consistently underestimated the peak concentrations of herbicides in paddy water within the first three days of simulation. Simulation results suggested that approximately 50 % of the total applied herbicide was lost from the paddy system. Increasing the duration of the water holding period after pesticide application or increasing the storage capacity of the rice field via excess water storage depth management has the potential to reduce greatly herbicide loss to below 10 % of the total applied herbicide.

Harnessing multifunctional antimony doped Tin (IV) sulfide nanosheets for chlorpyrifos degradation and hydrogen evolution

Multifunctional photocatalysts are vital for advancing environmental sustainability and clean energy. The hydrothermal method helped in optimized antimony (Sb) doping in the Tin (IV) sulfide (SnS2) lattice, increasing surface area with nanosheet assortment, as confirmed by Scanning Electron Microscopy and BET (Brunauer, Emmett and Teller) analysis. Moreover, the Fermi level shift towards conduction band within the semiconductor, increasing free electron concentration which enhanced conductivity and altered electronic properties. Photocatalysts were evaluated for Chlorpyrifos pesticide degradation, with studies conducted on photocatalytic parameters such as catalyst dosage, pesticide concentration, and pH to ascertain optimal degradation conditions. The 6 wt% Sb-doped SnS2 (6Sb:SnS2) demonstrated highest degradation efficiency within 60 min and degradation obeyed a pseudo first-order kinetic model with a rate constant of 0.0349 min−1. The degradation pathway of Chlorpyrifos and its transformation products was elucidated through High-Performance Liquid Chromatography-tandem mass spectroscopy. In addition, Sb doping empowers the surface traps and hydrophilicity of photocatalysts towards successful interaction between photogenerated electrons/holes with adsorbed oxidizable/reducible species. Moreover, 6Sb:SnS2 exhibited superior hydrogen evolution of 214.39 µmolg−1h−1, along with improved stability. Significantly, 6Sb:SnS2 attained Apparent Quantum Yield (AQY400 nm) of 39.49 % attributed to the doping induced band structure modification of SnS2 to match the hydrogen ion reduction potential

Simultaneous detection of carbendazim and pendimethalin residues using a compact Raman spectrometer

Abstract Surface-enhanced Raman spectroscopy (SERS) exhibits significant latent capacity in the prompt and accurate detection of minute concentrations of pesticides. In this study, carbendazim and pendimethalin were simultaneously detected within tobacco foliage by utilizing a PS@Ag composite substrate coupled with a compact Raman spectrometer. The detection limits for carbendazim is 0.1 mg/kg, and for pendimethalin, it is 5 mg/kg. The recovery rates for carbendazim within tobacco foliage ranged from 85.2% to 112.12%. And the recovery rates for pendimethalin ranged from 90.38% to 113.42%. The combination of the PS@Ag composite substrate in conjunction with a Raman spectrometer provides a highly effective means for the concurrent identification of pesticides in tobacco foliage.

Comparative adsorption of selected pesticides from aqueous solutions by activated carbon and biochar

ABSTRACT This work aimed to determine activated carbon (AC) and hard wood derived biochar (BC) adsorption capacity for the uptake of four pesticides atrazine, chlorothalanil, α-endosulfan and β-endosulfan from aqueous solution by conducting batch experiments under different experimental conditions. Structural properties of AC and BC were determined through ‘SEM (Scanning Electron Microscope), FTIR (Fourier Transform Infrared Spectrometer) and XRD (X-ray Powder Diffraction Spectroscopy)’. The optimized pH, particle size, contact time, agitation speed and initial pesticides concentration for the maximum adsorption rates were found to be 7, 250 μm, 60 min, 180 rpm and 12 μgL−¹ respectively. Pesticides adsorption were enhanced by increasing pH to 7 while slight decrease were noted when pH increases from 7 to 9. The adsorption equilibrium data were well described by the Langmuir isotherm model having a significant correlation coefficient value from 0.9999 to 1. Adsorption kinetic data were well fitted with the Lagergren's Pseudo-Second-Order kinetic model. The standard Gibb's free energy (ΔG) negative value at every temperature shows the practicability and spontaneity of the adsorption process. While the negative value for enthalpy change (ΔH) indicated the collective impact of exothermic adsorptions process with randomness intensifying due to positive entropy change.

Modern problems of Ukraine's ecology: agricultural pollutants and the quality of drinking water in the city of Kyiv

Considered modern problems of Ukraine's ecology. The problem “influence of agriculture on the quality of underground water” is considered in detaile. In 1998-2002, 163 analyzes of underground waters of the aquifer of Cenomanian sediments and the aquifer of Jurassic sediments in the city of Kyiv for the content of persistent chlorine-organic pesticides: DDT and its metabolites, hexachlorocyclohexane (HCCH) and its isomers, aldrin, heptachlor and the fluor-containing pesticide treflane were carried out by the gas-chromatographic method. In the water of the aquifer of Cenomanian sediments and the aquifer of Jurassic sediments of the city of Kyiv, the average concentration of DDT was at the level of 10-5 mg/dm3. According to our calculations for the year 2024, the concentration of the amount of DDT in the drinking groundwater of the city of Kyiv has decreased by 2-3 orders of magnitude, depending on natural conditions. This indicates that there no new inputs of DDT to natural ecosystems, and retrospective contamination is gradually decreasing. The need to conduct fundamental research of establishing concentrations of new pesticides in groundwater, developing criteria for assessing the danger of co-presence of pesticides of various classes of chemical compounds in groundwater and other natural objects remains relevant. In 2023-2024, 58 wells were examined for the quality of drinking water in Kyiv.

Salinization and low-dose levels of pesticides alter brain shape of larval amphibians

Wetland communities are increasingly threatened by multiple stressors simultaneously, such as pesticides and salinization. We examined the effects of ecologically-relevant exposures to broad-spectrum insecticides and salinization on amphibian neurodevelopment, which is strongly linked to how organisms respond behaviorally to environmental change. Prior research showed that exposure to trace concentrations of an organophosphate pesticide (chlorpyrifos) altered the brain shape and behavior of larval and metamorphic amphibians. It is unknown whether brain shape is altered by additional pesticides and road salt. Using outdoor mesocosms, we tested whether salt (NaCl) and representatives from three pesticide families (organophosphates, pyrethroids, and neonicotinoids) altered tadpole (Lithobates pipiens) brain shape. Of the two organophosphates, chlorpyrifos induced relatively longer telencephalon lengths relative to body mass, consistent with previous studies, but malathion had no effect on brain shape. Of the two pyrethroids, permethrin, but not cypermethrin, increased telencephalon length. For the neonicotinoids, there were marginally significant effects of imidacloprid and thiamethoxam on telencephalon length. Thus, the impacts of pesticides on brain shape was not dictated by pesticide family. Exposure to relatively high concentrations of salt resulted in brains that were less wide but had longer optic tecta. Although we failed to find strong interactive effect of salt with pesticides, there was some weak, nonsignificant, evidence that exposure to salt masked responses to pesticides. Together, our results indicate that environmentally realistic levels of pesticides and salinization can alter larval brain shape. Our study highlights the importance of studying the impacts of naturally-occurring levels of pesticides and salinization on vertebrate neural development.

The adsorption of chlorpyrifos and malathion under environmentally relevant conditions using biowaste carbon materials

Water bodies face persistent contamination from organophosphorus pesticides like chlorpyrifos and malathion, which pose substantial environmental and health hazards due to their toxicity and resilience in ecosystems. This study explores the potential of spent coffee grounds, a common agricultural byproduct, as an eco-friendly adsorbent for eliminating these pesticides from polluted water. Spent coffee grounds underwent carbonization at 400 °C and various activation treatments using KOH, H3PO4, CO2, and their combinations. The impact of these activation methods on the adsorption capacity of carbonized materials was assessed under environmentally relevant conditions (25 °C, pH=6, and typical pesticide concentrations in wastewater). Results revealed that the physical and chemical properties of biowaste-derived materials significantly influence their adsorption efficiency, with KOH-activated adsorbents exhibiting the highest capacities ((16.1 ± 0.8) mg g−1 for chlorpyrifos and (11.2 ± 0.2) mg g−1 for malathion). Spent coffee grounds carbonized at 400 °C without additional activation demonstrated similar adsorption performance to the best-performing material ((19.4 ± 0.4) mg g−1 for chlorpyrifos and (10.6 ± 0.4) mg g−1 for malathion), with notably lower economic and environmental costs. Given its straightforward preparation and significant adsorption capacity, this material stands out as a sustainable solution for treating agrochemical wastewater containing chlorpyrifos and malathion.