RESUMEN

This study explores the use of algae for phycoremediation, focusing on how Chlorella sorokiniana and Anabaena laxa detoxify water contaminated with captan, a common fungicide. The efficiency of these species in absorbing captan and the associated biochemical changes were evaluated to assess their potential for environmental protection. Microalgae were exposed to captan concentrations of 15 and 30 mg/L, and various parameters, including captan uptake, chlorophyll (Chl) a, carotenoid levels, and changes in metabolic profiles (soluble carbohydrates, organic acids, amino acids, and fatty acids), were measured. Results showed Anabaena had a higher captan absorption capacity (141.7 µg/g at 15 mg/L and 239.3 µg/g at 30 mg/L) compared to Chlorella (74.43 µg/g and 162 µg/g). Increased captan uptake reduced the growth of both species, as indicated by lower Chl a levels. Both species accumulated osmo-protectants and antioxidants as defense mechanisms, with soluble sugars increasing by 83.49% in Chlorella and 68.87% in Anabaena, and carotenoids increasing by 60.42% and 46.24%, respectively. Principal component analysis revealed distinct species-level responses, with Anabaena showing greater tolerance. The study concludes that both species can effectively remediate captan, with Anabaena being more efficient, indicating their potential for mitigating agrochemical impacts in aquatic environments and promoting sustainable agriculture and water management.

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This study uniquely demonstrates the superior capability of Anabaena laxa over Chlorella sorokiniana in remediating captan-contaminated water, highlighting distinct biochemical responses and enhanced tolerance mechanisms. By detailing species-specific metabolic adaptations, it underscores the potential of Anabaena for more effective phycoremediation. This novel insight into the differential resilience of microalgae species offers a promising approach to mitigating agrochemical pollution, advancing sustainable agriculture, and improving water management practices.

RESUMEN

An in vitro study using rainbow trout spermatozoa was designed to evaluate the toxic effects of different concentrations of captan (CPT), mancozeb (MCZ), and azoxystrobin (AZX) fungicides on motility parameters, lipid peroxidation, SOD activity, total antioxidant capacity (TAC), and DPPH inhibition. Moreover, changes in fatty acids profiles caused by the fungicides were determined for the first time. The results revealed that motility parameters, SOD activities, TAC values, and DPPH inhibitions decreased significantly while lipid peroxidation increased after ≥2 µg/L of CPT, ≥1 µg/L of MCZ, and ≥5 µg/L of AZX incubations for 2 h at 4 °C. Additionally, 10 µg/L CPT, 5 µg/L MCZ, and 200 µg/L AZX reduced motility to the 50 % level. Our results clearly demonstrated significant changes in the fatty acids profiles of spermatozoa exposed to these concentrations of the fungicides. The highest lipid peroxidation and the lowest monounsaturated and polyunsaturated saturated fatty acids (MUFA and PUFA, respectively) were detected in AZX. Even though the susceptibility of spermatozoa to oxidative damage is generally attributed to PUFA contents, the results of this study have represented that MUFA content could play a part in this tendency. Moreover, the lower concentration of MCZ reduced motility to the % 50 level while it deteriorated the fatty acids profile less than did AZX. Overall, the present study demonstrated that the detrimental effects of the fungicides on mitochondrial respiration and related enzymes have more priority than oxidative stress in terms of their toxicities on spermatozoa. It has also been suggested that fish spermatozoa are a good model for determining changes in the fatty acid profiles by fungicides, probably, by other pesticides and environmental contaminants as well.

Asunto(s)

Captano , Ácidos Grasos , Fungicidas Industriales , Maneb , Oncorhynchus mykiss , Estrés Oxidativo , Pirimidinas , Motilidad Espermática , Espermatozoides , Estrobilurinas , Contaminantes Químicos del Agua , Zineb , Animales , Masculino , Fungicidas Industriales/toxicidad , Estrés Oxidativo/efectos de los fármacos , Espermatozoides/efectos de los fármacos , Zineb/toxicidad , Maneb/toxicidad , Ácidos Grasos/metabolismo , Motilidad Espermática/efectos de los fármacos , Estrobilurinas/toxicidad , Contaminantes Químicos del Agua/toxicidad , Pirimidinas/toxicidad , Oncorhynchus mykiss/fisiología , Captano/toxicidad , Peroxidación de Lípido/efectos de los fármacos , Metacrilatos/toxicidad , Antioxidantes/metabolismo , Superóxido Dismutasa/metabolismo

RESUMEN

Captan dislodgeable foliar residues (DFRs) were determined by following the applications of this fungicide in an apple orchard. The study comprised an investigation of the variability of captan DFR values and 14 days of DFR monitoring to assess kinetic modeling. A method combining solid-phase microextraction (SPME) gas chromatography and high-resolution mass spectrometry (GC-QTOF-MS) was developed for the quantification of captan residues from DFR aqueous extracts. The results evidenced that (1) sampling parameters such as the position of the tree in a row and the height of foliar significantly influenced captan DFR levels (247-1450 ng·cm-2), highlighting the need to implement a comprehensive sampling strategy; (2) the DFR captan dissipation kinetic model best matched with a biphasic one, with half-lives of DFRcaptan of 3.4 and 12.8 days, respectively, for the initial rapid phase 1 decline (day 0-5) and the slower phase 2 decline phase (day 6-14). Furthermore, through DFR measurements, the potential dermal exposure (PDE) of workers was assessed using transfer coefficients (TCs) from the literature. Compared to the acceptable operator exposure levels (AOELs), the results showed that the re-entry interval for captan may not sufficiently protect workers whose arms, hands, and legs are not covered.

Asunto(s)

Captano , Fungicidas Industriales , Malus , Exposición Profesional , Malus/química , Humanos , Residuos de Plaguicidas , Hojas de la Planta/química , Microextracción en Fase Sólida

RESUMEN

On 24 July 2020, the EFSA conclusion on the peer review of the pesticide risk assessment of the active substance captan drawn in the context of the renewal of approval of the active substance captan conducted in accordance with Commission Implementing Regulation (EC) No 844/2012 was approved. In December 2023, the European Commission asked EFSA to provide a statement on its view as regards the RMS's revised environmental risk assessment concerning some uses in pome fruits and cherries and the potential impact of the recent new classification recommended by RAC on the toxicological reference values of captan stated in the EFSA Conclusion. The current statement contains the conclusions of the considerations related to the environmental revised risk assessment performed by the RMS, Austria, and to the new classification proposed by RAC on the toxicological reference values.

RESUMEN

There are few published data on the impact of combined exposure to multiple pesticides (coexposure) on levels of biomarkers of exposure in workers, which may alter their toxicokinetics and thus the interpretation of biomonitoring data. This study aimed to assess the impact of coexposure to two pesticides with shared metabolism pathways on levels of biomarkers of exposure to pyrethroid pesticides in agricultural workers. The pyrethroid lambda-cyhalothrin (LCT) and the fungicide captan were used as sentinel pesticides, since they are widely sprayed concomitantly in agricultural crops. Eighty-seven (87) workers assigned to different tasks (application, weeding, picking) were recruited. The recruited workers provided two-consecutive 24-h urine collections following an episode of lambda-cyhalothrin application alone or in combination with captan or following tasks in the treated fields, as well as a control collection. Concentrations of lambda-cyhalothrin metabolites - 3-(2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethyl-cyclopropanecarboxylic acid (CFMP) and 3-phenoxybenzoic acid (3-PBA) - were measured in the samples. Potential determinants of exposure established in a previous study, including the task performed and personal factors were documented by questionnaire. Multivariate analyses showed that coexposure did not have a statistically significant effect on the observed urinary levels of 3-PBA (Exp(ß) (95% confidence interval (95% CI)): 0.94 (0.78-1.13)) and CFMP (1.10 (0.93-1.30). The repeated biological measurements ("time variable") - defined as the within-subjects variable - was a significant predictor of observed biological levels of 3-PBA and CFMP; the within-subjects variance (Exp(ß) (95% (95% CI)) for 3-PBA and CFMP was 1.11 (1.09-3.49) and 1.25 (1.20-1.31). Only the main occupational task was associated with urinary levels of 3-PBA and CFMP. Compared to the weeding or picking task, the pesticide application task was associated with higher urinary 3-PBA and CFMP concentrations. In sum, coexposure to agricultural pesticides in the strawberry fields did not increase pyrethroid biomarker concentrations at the exposure levels observed in the studied workers. The study also confirmed previous data suggesting that applicators were more exposed than workers assigned to field tasks such as weeding and picking.

Asunto(s)

Insecticidas , Plaguicidas , Piretrinas , Humanos , Insecticidas/orina , Agricultores , Captano , Monitoreo del Ambiente , Piretrinas/orina , Plaguicidas/orina , Biomarcadores/orina

RESUMEN

Accurate and highly sensitive analysis of folpet and captan was accomplished using liquid chromatography-triple quadrupole linear ion trap mass spectrometry (LC-QqQIT) with selective ion mode; mass filtering, collision, and trapping condition. Dimensional mass spectrometry (MS3) parameters were optimized for the residue detection of folpet and captan in six food commodities (apples, tomatoes, sweet pepper, wheat flour, sesame seeds, and fennel seeds). The sample preparation method was based on the known QuEChERS protocol, except a mixture of acetonitrile/acetone was used for the sample extraction from the sesame seeds. The robustness and reliability of the developed MS3 method were demonstrated by performing a full validation, according to SANTE/11312/2021, at 0.01-0.25 mg/kg. Recovery ranged from 83 to 118% with a relative standard deviation below 19% in all the tested commodities, and limits of quantifications (LOQs) were 0.01 mg/kg in apples and tomatoes; 0.03 mg/kg in sweet pepper; and 0.05 mg/kg in wheat flour, sesame seeds, and fennel seeds. Monitoring results showed that about 90% of apples contained captan residue, and in sweet pepper, concentrations of captan and folpet as high as 1.57 and 0.97 mg/kg were found, respectively. The novel developed MS3 method enabled more reliable identification of these commonly problematic fungicides at lower LOQs than previously reported methods.

Asunto(s)

Captano , Malus , Harina/análisis , Reproducibilidad de los Resultados , Triticum , Cromatografía de Gases y Espectrometría de Masas/métodos , Cromatografía Liquida/métodos , Malus/química , Cromatografía Líquida de Alta Presión

RESUMEN

The excessive use of fungicides against Venturia inaequalis, the causal agent of apple scab, has led to the emergence of resistant populations to multiple fungicides over the years. In Greece, there is no available information on fungicide resistance, despite the fact that control failures have been reported on certain areas. An amount of 418 single-spore isolates were collected from three major apple production areas and tested for their sensitivity to eight commonly used fungicides from unrelated chemical groups. The isolates were tested on malt extract agar media enriched with the discriminatory dose of each fungicide using the point inoculation method. To define the discriminatory dose for assessing the levels of resistance, EC50 values on both spore germination and mycelial growth assays were previously determined. Isolates exhibiting high resistance to trifloxystrobin (92% in total) and difenoconazole (3%); and moderate resistance to cyprodinil (75%), dodine (28%), difenoconazole (36%), boscalid (5%), and fludioxonil (7%) were found for the first time in Greece. A small percentage of the isolates were also found less sensitive to captan (8%) and dithianon (6%). Two isolates showed various levels of resistance to all eight fungicides. Despite the occurrence of strains with multiple resistances to many fungicides, we concluded that this practical resistance in the field arose mainly due to the poor control of apple scab with trifloxystrobin and difenoconazole.

RESUMEN

There are limited literature data on the impact of coexposure on the toxicokinetics of pesticides in agricultural workers. Using the largely employed pyrethroid lambda-cyhalothrin (LCT) and fungicide captan as sentinel pesticides, we compared individual temporal profiles of biomarkers of exposure to LCT in strawberry field workers following an application episode of LCT alone or in coexposure with captan. Participants provided all urine voided over a 3-day period after an application of a pesticide formulation containing LCT alone (E1) or LCT mixed with captan (E2), and in some cases following re-entry in treated field (E3). Pyrethroid metabolites were measured in all urine samples, in particular 3-(2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethyl-cyclopropanecarboxylic acid (CFMP), 3-phenoxybenzoic acid (3-PBA), and 4-hydroxy-3-phenoxybenzoic acid (4-OH3PBA). There were no obvious differences in individual concentration-time profiles and cumulative excretion of metabolites (CFMP, 3-PBA, 4-OH3BPA) after exposure to LCT alone or in combination with captan. For most workers and exposure scenarios, CFMP was the main metabolite excreted, but time courses of CFMP in urine did not always follow that of 3-PBA and 4-OH3BPA. Given that the latter metabolites are common to other pyrethroids, this suggests that some workers were coexposed to pyrethroids other than LCT. For several workers and exposure scenarios E1 and E2, values of CFMP increased in the hours following spraying. However, for many pesticide operators, other peaks of CFMP were observed at later times, indicating that tasks other than spraying of LCT-containing formulations contributed to this increased exposure. These tasks were mainly handling/cleaning of equipment used for spraying (tractor or sprayer) or work/inspection in LCT-treated field according to questionnaire responses. Overall, this study provided novel excretion time course data for LCT metabolites valuable for interpretation of biomonitoring data in workers, but also showed that coexposure was not a major determinant of variability in exposure biomarker levels. Our analysis also pointed out the importance of measuring specific metabolites.

Asunto(s)

Fragaria , Insecticidas , Plaguicidas , Piretrinas , Biomarcadores/orina , Captano/toxicidad , Monitoreo del Ambiente , Agricultores , Humanos , Insecticidas/farmacocinética , Insecticidas/toxicidad , Nitrilos , Plaguicidas/toxicidad , Piretrinas/toxicidad

RESUMEN

The sub-lethal toxicity of Captan® on selected haematological (Hemoglobin, Haematocrit, Mean Corpuscular Hemoglobin) growth (Condition factor, Hepatosomatic Index, Specific Growth Rate), biochemical (serum glucose, protein), and endocrine parameters (growth hormone, T3 and T4) in Clarias batrachus was examined under chronic exposures. Captan® was administered at predetermined exposure concentrations (0.53 and 1.06 mg/L) and monitored on days 15, 30, and 45 of the experimental periods. The experimental groups showed significantly lower values (p < 0.05) of haemoglobin content, hematocrit, MCH in Captan® exposed fish compared to control. Serum protein, k-factor and SGR were significantly lower in exposed fish. Endocrine responses (T3 and T4) emerged as the most sensitive biomarker category, depicting modulated responses between sub-chronic exposure at day-15 and chronic responses at day-45. In general, biomarker depictions indicate that Captan® exposures are capable of inducing stress-specific effects at the biochemical and physiological levels negatively impacting the overall health and longevity of such animals.

Asunto(s)

Biomarcadores/sangre , Captano/toxicidad , Bagres/sangre , Animales , Bagres/crecimiento & desarrollo , Fungicidas Industriales/toxicidad , Hematócrito , Hemoglobinas/análisis , Tiroxina/sangre , Triyodotironina/sangre , Contaminantes Químicos del Agua/toxicidad

RESUMEN

Captan is one of the most widely used organochlorine fungicides, its frequent application contaminates both terrestrial and aquatic ecosystems and negatively affects their key ecological processes. This study demonstrated the toxicity and efficient removal of captan by two different taxonomic species; the green microalga Scenedesmus obliquus and cyanobacterium Nostoc muscorum. After a week of exposure to mild (15 mg/L) and severe (30 mg/L) captan doses, the intracellular captan uptake, degradation and metabolic regulation of captan detoxification were studied. Compared to N. muscorum, S. obliquus accumulated more captan, but efficiently degraded it into two safe eco-friendly by-products; phthalic acid and 1,2,3,6-tetrahydro phthalimide. S. obliquus showed less decrease in cell growth, photosynthesis activity and related parameters including Chla content and activity of PEPC and RuBisCo enzymes. Captan at the severe dose induced oxidative damage particularly in N. muscorum, as expressed by the high levels of H2O2, MDA, NADPH oxidase and protein peroxidation. Both species invested glutathione-s-transferase enzyme in captan detoxification however, induction of antioxidant defence system e.g. ascorbate and glutathione cycle was more pronounced in S. obliquus which could explain its tolerance ability. This study provided a better understanding of the environmental risks of captan and introduced S. obliquus as a promising captan phycoremediator.

Asunto(s)

Microalgas , Nostoc , Scenedesmus , Antioxidantes , Captano , Ecosistema , Peróxido de Hidrógeno

RESUMEN

OBJECTIVE: Although apple trees are heavily sprayed, few studies have assessed the pesticide exposure of operators and workers in apple orchards. However, these data are crucial for assessing the health impact of such exposures. The aim of this study was to measure pesticide exposure in apple growing according to tasks and body parts. METHODS: A non-controlled field study was conducted in apple orchards in 4 regions of France during the 2016 and 2017 treatment seasons. Workers' external contamination and their determinants were assessed over 156 working days corresponding to 30 treatment days, 68 re-entry days and 58 harvesting days. We measured pesticide dermal contamination during each task and made detailed observations of work characteristics throughout the day. Captan and dithianon were used as markers of exposure. RESULTS: The median dermal contamination per day was 5.50 mg of captan and 3.33 mg of dithianon for operators, 24.39 mg of captan and 1.84 mg of dithianon for re-entry workers, and 5.82 mg of captan and 0.74 mg of dithianon for harvesters. Thus, workers performing re-entry tasks, especially thinning and anti-hail net opening, presented higher contamination, either equal to or higher than in operators. For these last ones, mixing/loading and equipment cleaning were the most contaminating tasks. Most of the contamination was observed on workers' hands in all tasks, except for net-opening in which their heads accounted for the most daily contamination. CONCLUSIONS: This study highlights the importance of taking indirect exposures into account during re-entry work in apple growing.

Asunto(s)

Malus , Exposición Profesional , Plaguicidas , Captano/análisis , Humanos , Exposición Profesional/análisis , Estaciones del Año

RESUMEN

Captan is a non-systematic fungicide widely used in agricultural production, and its residues have been found in the environment and daily diet. Previous studies confirmed that captan exerts several toxic effects on tissues, but its effect on the mammalian female reproductive system is unclear. In current study, we reported that captan affected mouse ovarian homeostasis and disrupted female hormone receptor expression, leading to impaired follicular development. Ovarian follicles from the captan exposure group showed an increased level of inflammation, endoplasmic reticulum stress and apoptosis. In addition, captan exposure disrupted oocyte development. Transcriptomic analysis indicated that captan changed multiple genes expression in oocytes, including autophagy and apoptosis. Further molecular testing showed that captan induced oxidative stress and mitochondrial dysfunction, as indicated by the increased level of reactive oxygen species, disrupted mitochondrial structure and distribution, and depolarized membrane potential. Furthermore, captan triggered DNA damage, autophagy and early apoptosis, as shown by the enhanced levels of γ-H2AX, LC3, and Annexin-V and increased expression of related genes. Taken together, these results indicated that captan exposure impairs ovarian homeostasis and subsequently affects oocyte development.

Asunto(s)

Captano , Oocitos , Animales , Apoptosis , Captano/metabolismo , Femenino , Homeostasis , Ratones , Mitocondrias/metabolismo , Oocitos/metabolismo , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo

RESUMEN

Pesticides have been used in large amounts around the world for decades and are responsible for environmental pollution and various adverse effects on human health. Analysis of untreated wastewater can deliver useful information on pesticides' use in a particular area and allow the assessment of human exposure to certain substances. A wide-scope screening method, based on liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry, was applied, using both target and suspect screening methodologies. Daily composite influent wastewater samples were collected for seven or eight consecutive days in Athens between 2014 and 2020 and analyzed for 756 pesticides, their environmental transformation products and their human metabolites. Forty pesticides were quantified at mean concentrations up to 4.9 µg/L (tralkoxydim). The most abundant class was fungicides followed by herbicides, insect repellents, insecticides and plant growth regulators. In addition, pesticide transformation products and/or metabolites were detected with high frequency, indicating that research should be focused on them. Human exposure was evaluated using the wastewater-based epidemiology (WBE) approach and 3-ethyl-carbamoyl benzoic acid and cis-1,2,3,6-tetrahydrophthalimide were proposed as potential WBE biomarkers. Wastewater analysis revealed the presence of unapproved pesticides and indicated that there is an urgent need to include more transformation products in target databases.

RESUMEN

Apple scab is one of the most economically important diseases of apple in temperate production regions. In the absence of durable host resistance in commercially preferred cultivars, considerable applications of fungicides are needed to manage this disease. With the sequential development of resistance to nearly all classes of single-site fungicides in the apple scab pathogen Venturia inaequalis, synthetic multisite fungicides, such as mancozeb and captan, often comprise the core of chemical management programs for apple scab. Although these fungicides have demonstrable benefits for both disease and fungicide resistance management, the sustainability movement within agriculture aims to reduce reliance on such fungicides because of their broader environmental impacts. In this study, we establish a framework to enhance the feasibility of chemical management programs that do not rely on use of synthetic multisite protectant fungicides to manage apple scab. Specifically, we wish to evaluate chemical programs that integrate the biopesticide Bacillus subtilis QST 713 (Serenade Opti) in rotation with benzovindiflupyr (Aprovia), a single-site fungicide belonging to the class of succinate dehydrogenase inhibitors (SDHI), to circumvent the need for applications of synthetic multisite fungicides. During implementation of these programs, disease incidence data were taken at biweekly intervals. Regardless of the seasonal challenges presented in the 2 years of this study, when Bacillus subtilis QST 713 was used in place of captan and mancozeb mixtures, we did not observe any significant differences (P > 0.05) in development of apple scab symptoms between any of the management programs for the vertical axis or super spindle orchards in either year. This potential for substituting synthetic multisite fungicides with biopesticides is best realized when the programs are used with a decision support system in a super spindle planting system, where trees have reduced canopy densities. This 2-year study shows the potential to achieve adequate disease control using the integration of SDHI fungicides and biological controls without the use of synthetic multisite fungicides.

Asunto(s)

Ascomicetos , Fungicidas Industriales , Malus , Bacillus subtilis , Agentes de Control Biológico , Captano , Fungicidas Industriales/farmacología , Maneb , Norbornanos , Enfermedades de las Plantas , Pirazoles , Zineb

RESUMEN

Pesticide leaching and soil contamination are major issues in the present agriculture formulations. Hence, here 2D graphene oxide in combination with cationic, anionic, or nonionic polymers were tested for runoff resistance and targeted release behavior. Cationic polymer supplemented the binding of rGO on leaf surface by 30% more than control and reduced off-target leaching in soil by 45% more than control. Further, to enhance the fruit rot control caused by Colletotrichum capsici in chili crop, the rGO was decorated with Cu2-xSe nanocrystals, which provided combined disease control with captan. The chitosan coating in the nanocomposite added targeted pH-responsive fungal inhibition behavior and could reduce the C. capsici growth by ∼1/2 times compared to captan control.

Asunto(s)

Captano/farmacología , Quitosano/farmacología , Colletotrichum/efectos de los fármacos , Fungicidas Industriales/farmacología , Grafito/farmacología , Enfermedades de las Plantas/prevención & control , Captano/química , Quitosano/química , Colletotrichum/crecimiento & desarrollo , Frutas/química , Fungicidas Industriales/química , Grafito/química , Concentración de Iones de Hidrógeno , Pruebas de Sensibilidad Microbiana , Nanocompuestos/química , Tamaño de la Partícula , Propiedades de Superficie

RESUMEN

The quantitative determination of multiple pesticide residues in food is an iterative process given the frequent changes in monitoring specifications set by regulatory authorities, introduction of new pesticide active ingredients, variety of commodities encountered and advances in the capability of analytical instrumentation and software platforms. The method described here:•replaces our previous methodology [1] that was based on an ethyl acetate extraction [2], two different sample extract clean-up regimes depending on the commodity; either Gel Permeation Chromatography (GPC) or Solid Phase Extraction (SPE) and GC/MSMS analysis using cool on-column injection and permits higher throughput using the same QuEChERS extraction method used for LCMS/MS analysis [3]•uses PTV injection incorporating a deactivated (baffled) injection liner required to improve performance for 'difficult to analyse' pesticides e.g. captan, dichlofluanid, folpet, tolylfluanid.•has been validated for the quantitative determination of 113 different pesticides and their metabolites in a range of fruit and vegetables of high water content and high acid and high water content i.e. cabbage, lemon, pepper, plum and spinach and complies with requirements of European Commission guidance document on Analytical Quality Control and Method Validation Procedures for Pesticides Residues Analysis in food and feed - SANTE/12682/2019 [4].

RESUMEN

Serious difficulties in evaluating the fungicides captan and folpet by the usual chromatography systems coupled to mass spectrometry are well known. These compounds are highly prone to degradation due to different conditions into tetrahydrophthalimide (THPI) and phthalimide (PHI). Such an effect can be produced at different stages of the analytical procedure or during the growing crop, making their evaluation troublesome. As a consequence, the quantification of captan and folpet is typically performed through or together these metabolites. However, imide ring metabolites can be produced by other unknown sources, including other phthalimide derived pesticides enabling false positive results. For this reason, in the last decade, laboratories demand a robust method to quantify captan and folpet, that overcomes such a situation. In the present work, various operational parameters were optimized to ensure the no degradation of captan and folpet facilitated by supercritical fluid chromatography coupled to mass spectrometry (SFC-MS/MS). A direct comparison with reverse-phase LC-MS/MS and GC-MS/MS was conducted for comparative purposes. The representative commodities selected for this evaluation were pepper and tomato. Furthermore, possible oxidative degradation during the sample milling step was also evaluated and avoided by the application of crio-milling conditions and ascorbic acid addition. By the proposed procedure, captan and folpet were recovered in both matrices at the 84%-105% range and with an RSD below 8% at two concentration levels: 10 and 50 µg/kg. On the contrary, with GC-MS/MS, captan and folpet were not recovered, and, as a consequence, their evaluation was possible only by THPI and PI. In the case of LC-MS/MS a significant decrease in the sensitivity was observed compared to SFC-MS/MS. Other validation parameters evaluated were satisfactory. This new approach can assess the correct analysis of captan and folpet at low concentrations in fruits and vegetables.

RESUMEN

Small intestinal (SI) tumors are relatively uncommon outcomes in rodent cancer bioassays, and limited information regarding chemical-induced SI tumorigenesis has been reported in the published literature. Herein, we propose a cytotoxicity-mediated adverse outcome pathway (AOP) for SI tumors by leveraging extensive target species- and site-specific molecular, cellular, and histological mode of action (MOA) research for three reference chemicals, the fungicides captan and folpet and the transition metal hexavalent chromium (Cr(VI)). The gut barrier functions through highly efficient homeostatic regulation of SI epithelial cell sloughing, regenerative proliferation, and repair, which involves the replacement of up to 1011 cells per day. This dynamic turnover in the SI provides a unique local environment for a cytotoxicity mediated AOP/MOA. Upon entering the duodenum, cytotoxicity to the villous epithelium is the molecular initiating event, as indicated by crypt elongation, villous atrophy/blunting, and other morphologic changes. Over time, the regenerative capacity of the gut epithelium to compensate declines as epithelial loss accelerates, especially at higher exposures. The first key event (KE), sustained regenerative crypt proliferation/hyperplasia, requires sufficient durations, likely exceeding 6 or 12 months, due to extensive repair capacity, to create more opportunities for the second KE, spontaneous mutation/transformation, ultimately leading to proximal SI tumors. Per OECD guidance, biological plausibility, essentiality, and empirical support were assessed using modified Bradford Hill considerations. The weight-of-evidence also included a lack of induced mutations in the duodenum after up to 90 days of Cr(VI) or captan exposure. The extensive evidence for this AOP, along with the knowledge that human exposures are orders of magnitude below those associated with KEs in this AOP, supports its use for regulatory applications, including hazard identification and risk assessment.

Asunto(s)

Captano/toxicidad , Cromo/toxicidad , Fungicidas Industriales/toxicidad , Hiperplasia , Neoplasias Intestinales/inducido químicamente , Ftalimidas/toxicidad , Rutas de Resultados Adversos , Animales , Duodeno , Humanos , Ratones , Medición de Riesgo

RESUMEN

The conclusions of EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State Austria and co-rapporteur Member State Italy for the pesticide active substance captan are reported and the confirmatory data following the Article 12 of Regulation (EC) No 396/2005 as well. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of captan as a fungicide on pome fruit, peaches and nectarines, plums, cherry, tomato, strawberries (field use) and strawberries (greenhouse application). The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.

RESUMEN

Many yeasts have demonstrated intrinsic insensitivity to certain antifungal agents. Unlike the fungicide resistance of medically relevant yeasts, which is highly undesirable, intrinsic insensitivity to fungicides in antagonistic yeasts intended for use as biocontrol agents may be of great value. Understanding how frequently tolerance exists in naturally occurring yeasts and their underlying molecular mechanisms is important for exploring the potential of biocontrol yeasts and fungicide combinations for plant protection. Here, yeasts were isolated from various environmental samples in the presence of different fungicides (or without fungicide as a control) and identified by sequencing the internal transcribed spacer (ITS) region or through matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Among 376 isolates, 47 taxa were identified, and Aureobasidium pullulans was the most frequently isolated yeast. The baseline sensitivity of this yeast was established for 30 isolates from different environmental samples in vitro to captan, cyprodinil, and difenoconazole. For these isolates, the baseline minimum inhibitory concentration (MIC50) values for all the fungicides were higher than the concentrations used for the control of plant pathogenic fungi. For some isolates, there was no growth inhibition at concentrations as high as 300 µg/mL for captan and 128 µg/mL for cyprodinil. This information provides insight into the presence of resistance among naturally occurring yeasts and allows the choice of strains for further mechanistic analyses and the assessment of A. pullulans for novel applications in combination with chemical agents and as part of integrated plant-protection strategies.