Water Resource Pollution by Herbicide Residues

Herbicides are frequently used in the chemical control of weeds in various crops in Brazil and worldwide, so they are more frequently detected outside the application areas, contributing to the risk of environmental contamination. The importance of knowledge of the physicochemical properties of the environment and the pesticide used in the agricultural area is in order to understand its effects on terrestrial and aquatic ecosystems and the search for the prevention of future bioaccumulation potentials (bioconcentration and/or biomagnification) of molecules of pesticides in living nontarget organisms, minimizing their negative effects on the environment. The understanding of analytical techniques for measuring the quality of water resources as well as techniques for the remediation of contaminated water is essential to minimize the possible impacts caused by the application of pesticides to the environment

Effect of Biochar Amendments on the Sorption and Desorption Herbicides in Agricultural Soil

Improved understanding of herbicide destinations, effects, and environmental risks through worldwide studies is crucial to minimizing impacts to nontarget organisms, especially in tropical regions rich in biodiversity. In recent years, there has been widespread international concern about the toxic effects of herbicides on humans, faunas, and native floras. Therefore, the adoption of agricultural practices that minimize the environmental effects of herbicides has been frequently studied, for example, the addition of biochar in agricultural soils. Biochar can be defined as the by-product of a thermal process conducted under low oxygen or oxygen-free conditions (pyrolysis) to convert plant biomass to biofuels, where biochar is the solid product of pyrolysis. The addition of biochar to the soil can easily potentiate the herbicide retention process, which, in addition to contributing positively to the reduction of chemical contaminants in the environment, may exert negative effects on herbicide behavior and the efficacy of these products on weed control. Thus, this chapter will present the general characteristics of biochar, as well as the impact of this material on sorption-desorption of herbicides in the soil

Is there an association between dental caries, fluorosis, and molar-incisor hypomineralization?

Objective: This cross-sectional study aimed to determine the prevalence of dental caries, dental fluorosis, and molar-incisor hypomineralization, and their associations in a group of Brazilian schoolchildren. Methodology:Adolescents (n=411) were evaluated by two calibrated examiners for dental caries (DC), dental fluorosis (DF), and molar-incisor hypomineralization (MIH) using the CAST (Caries Assessment Spectrum and Treatment) instrument, Thylstrup and Fejerskov (TF) index, and MIH Severity Scoring System (MIH-SSS), respectively. Descriptive statistics, chi-square tests, and logistic regression were used for statistical analysis. Results:The sample comprised 42.75% boys and 57.25% girls. The prevalence of DC in permanent dentition was 94.75%, of which 29% were represented by dentin lesions. For DF, a prevalence of 40.75% was observed, with 69.32% mild, 12.88% moderate, and 17.79% severe. A positive association between the source of water and fluorosis was detected (p=0.01). The prevalence of MIH was 18%. Thirty adolescents (41.7%) presented with severe MIH. No association was found between DF or MIH and dentin DC or between MIH and DF at the individual level. However, a significant negative relationship was detected between DF and dentin carious lesions ( p <0.005) and DF and MIH ( p <0.00001) at the tooth level, whereas a positive association was observed between MIH and dentin carious lesions ( p <0.00001). A positive association was also observed between the severity of both conditions ( p <0.00001). Mild DF was the most prevalent problem observed. Cases of teeth with mild MIH were the most predominant in MIH-affected teeth. Conclusions: No association was observed among the dentin carious lesions, MIH, and DF at the participant level. However, a positive association between MIH and dentin carious lesions was found at the tooth level, whereas MIH, DF, and DF and dentin carious lesions showed a negative relationship.&nbsp

Effectiveness of atrazine on populations of capim navalha and selectivity of two varieties of pastagem

O Paspalum virgatum L. é uma planta daninha comum de pastagens e possui difícil controle, principalmente devido sua semelhança com as forrageiras. As técnicas convencionais como gradagem e replantio da pastagem têm sido insatisfatórias no controle desta planta daninha. O objetivo deste trabalho foi avaliar o controle do capim-navalha (P. virgatum L.) à atrazine aplicada em pré-emergência, por meio de curva dose-resposta e a seletividade deste herbicida nas pastagens de Brachiaria brizantha cv. Marandu e Panicum maximum cv. Mombaça. Foram realizados três experimentos independentes, com cada espécie, em dois tipos de solo (Latossolo Vermelho Amarelo distrófico - LVAd de textura franco-argilosa e Argissolo Vermelho Amarelo distrófico - PVAd de textura franca), utilizando a escala percentual de notas para verificar o controle do capim-navalha e a fitotoxicidade nas forrageiras e massa seca no final dos experimentos. A atrazine controlou o capim-navalha, desde os 15 dias após a aplicação (DAA), nas doses abaixo da recomendação do fabricante (250 e 500 g ha-1 i.a.). Contudo, apesar dos sintomas de fitotoxicidade causados pela atrazine, houve retomada de crescimento aos 60 DAA tanto para B. brizantha cv. Marandu quanto para P. maximum cv. Mombaça. Houve menor fitotoxicidade às pastagens no solo de textura franco‑argilosa em relação ao solo de textura franca. A atrazine proporcionou controle eficiente do P. virgatum L. (500 g ha-1 i.a.) quando aplicada em pré-emergência e seletividade para B. brizantha cv. Marandu (<2.000 g ha-1 i.a.) e P. maximum cv. Mombaça (<500 g ha-1 i.a.).Paspalum virgatum L. is a grass weed common in pasture and has difficult control, mainly due to its similarity to forage. Conventional techniques such as grazing and replanting of pasture have been unsatisfactory in the control of this weed. The objective of this work was to evaluate the control of the razor-blade grass (P. virgatum L.) at the pre-emergence atrazine, by means of a dose‑response curve and the selectivity of this herbicide in the pastures of Brachiaria brizantha cv. Marandu and Panicum maximum cv. Mombasa. Three independent experiments were carried out with each species on two types of soils (Dystrophic Yellow Red Latosol - LVAd with loamy clay texture and Dystrophic Yellow Red Argisol - loamy texture PVAd), using the percentage grading scale to verify the control of the and herbage phytotoxicity and dry mass at the end of the experiments. Atrazine controlled the razor blade from 15 days after application (DAA) at doses below the manufacturer’s recommendation (250 and 500 g ha-1 i.a.). However, despite the phytotoxicity symptoms caused by atrazine, there was a resumption of growth at 60 DAA for both B. brizantha cv. Marandu and P. maximum cv. Mombasa. There was less phytotoxicity to pastures in the soil of loamy clay texture than the loamy texture soil. The atrazine provided efficient control of P. virgatum L. (500 g ha-1 i.a.) when applied in pre-emergence and selectivity to B. brizantha cv. Marandu (<2,000 g ha-1 i.a.) and P. maximum cv. Mombasa (<500 g ha-1 i.a.)

Eficácia do imazapic no controle de capim-camalote aplicado em solos de diferentes texturas

Itchgrass (Rottboelia exaltata L.f.) is a weed that presented fast dissemination in sugarcane fields in Brazil, causing significant yield losses to the crop. Therefore, this research had the objective of evaluating the susceptibility of the weed itchgrass to imazapic when applied in pre-emergence using dose-response curves. The experiments were carried out in randomized blocks experimental design with four replications in a factorial arrangement between two soil (clayey-sandy and sandy) and nine rates of imazapic. The herbicide rates were: 0; 9.19; 18.38; 36.75; 50; 73; 147; 294; 588 and 1176 g a.i. ha-1 and check without application. The sandy soil scored by visual control upper and lower levels of residual dry matter compared to the clayey-sandy soil. Soil texture has a direct influence on the effectiveness of control. Soil texture has a direct influence on control efficiency, so that the dose of 18.38 g a.i. ha-1 showed more control of itchgrass in sandy soil, while for clay and sandy soil was 294 g a.i. ha-1. Control levels indicate that application of imazapic in pre-emergence is viable to control the weed itchgrass.O capim-camalote (Rottboelia exaltata L.f.) é uma planta daninha com rápida capacidade de disseminação nas áreas canavieiras do Brasil, causando significativas perdas de produtividade na cultura. Assim, esta pesquisa teve como objetivo avaliar a suscetibilidade do capim-camalote ao herbicida imazapic, quando aplicado em pré-emergência, por meio de curvas de dose-resposta. O experimento foi desenvolvido no delineamento experimental do tipo blocos ao acaso com quatro repetições em esquema fatorial entre dois tipos de solo (franco argilo-arenoso e franco arenoso) e nove doses do herbicida imazapic. As doses utilizadas foram: 0; 9,19; 18,38; 36,75; 50; 73; 147; 294; 588 e 1176 g i.a. ha-1 e testemunha sem aplicação. O uso do imazapic causou maior controle e menor matéria seca do capim-camalote quando aplicado em solo franco arenoso, em relação ao solo franco argilo-arenoso. A textura do solo tem influência direta na eficiência de controle, de modo que a dose de 18,38 g i.a. ha-1 demonstrou maior controle do capim-camalote em solo franco arenoso, já para solo franco argilo-arenoso foi de 294 g i.a. ha-1. Os níveis de controle indicam a viabilidade de aplicação de imazapic em pré-emergência para controle do capim-camalote

Behavior aminocyclopyrachlor in function of the addition of organic material in soil

A matéria orgânica é um dos componentes mais influentes no comportamento de herbicidas aplicados via solo, podendo alterar a dinâmica destes compostos no ambiente. O objetivo deste estudo foi avaliar o efeito de solos alterados com palha de cana-de-açúcar, torta de filtro e vinhaça na sorção-dessorção, lixiviação, mineralização e degradação do aminoyclopyrachlor no solo. A sorção-dessorção foi verificada pelo método de equilíbrio em \"batch\", com os materiais orgânicos envelhecidos no solo (0, 15, 30 e 60 dias). A lixiviação foi realizada em colunas de vidro (200 mm em 48 horas) com as concentrações do herbicida aferidas no perfil do solo (0-0,30 m) e no lixiviado. A biodegradação foi conduzida por 112 dias, em frascos biométricos. A sorção do herbicida foi baixa para todos os tratamentos (Kd = 0,17-0,41 L kg-1), com dessorção de grande parte do herbicida aplicado. Menos de 2 % do herbicida esteve retido na palha e torta de filtro, com maior distribuição no perfil do solo. A vinhaça aumentou a lixiviação do herbicida (71 %) em relação aos demais materiais e o solo sem alteração (~50 %). A mineralização do aminocyclopyrachlor foi baixa (<45 % em 112 dias), havendo formação de ~30 % de resíduo ligado, sem a observação da formação de metabólitos ao longo do estudo. A meia-vida (DT50) no solo sem adição de material orgânico foi de 187 dias, com adição de materiais orgânicos chegou a 247-277 dias e 90 % de degradação foi estimada em 600-900 dias para todos os tratamentos. A presença de materiais orgânicos no solo promoveu maior disponibilidade do aminocyclopyrachlor em solução, principalmente para a lixiviação no perfil do solo, além de ter sua persistência aumentada no ambiente. A persistência do herbicida no ambiente favorece o controle mais prolongado de plantas daninhas, principalmente quando há maior disponibilidade no solo, porém no manejo deste herbicida em sistema de cana-de-açúcar, no qual há grande aporte de matéria orgânica no solo, podendo favorecer a contaminação de águas subterrâneasThe organic matter is one of the most influential components in the behavior of herbicides applied via soil, being able to alter the dynamics of these compounds in the environment. The objective of this study was to evaluate the effect of altered soils with sugarcane straw, filter cake and vinasse on sorption-desorption, leaching, mineralization and degradation of aminocyclopyrachlor in soil. Sorption-desorption was verified by the batch equilibrium method, with organic materials aged in the soil (0, 15, 30 and 60 days). The leaching was carried out in glass columns (200 mm in 48 hours) with the herbicide concentrations measured in the soil profile (0-0.30 m) and in the leachate. Biodegradation was conducted for 112 days in biometric vials. The sorption of the herbicide was low for all treatments (Kd = 0.17-0.41 L kg-1), with desorption of a large part of the herbicide applied. Less than 2 % of the herbicide was retained in straw and filter cake, with greater distribution in the soil profile. Vinasse increased herbicide leaching (71 %) in relation to other materials and soil without change (~ 50 %). Mineralization of aminocyclopyrachlor was low (<45 % in 112 days), with ~ 30 % formation of bound residue without observation of metabolite formation throughout the study. The half-life (DT50) in the soil without addition of organic material was 187 days, with addition of organic materials reached 247-277 days and 90 % degradation was estimated at 600-900 days for all treatments. The presence of organic materials in the soil promoted greater availability of aminocyclopyrachlor in solution, mainly for the leaching, besides having its persistence increased in the environment. The persistence of the herbicide in the environment favors the longer control of weeds, especially when there is greater availability in the soil, but in the management of this herbicide in a sugar cane system, in which there is a great contribution of organic matter in the soil, may favor the contamination of groundwate

Availability of Metribuzin-Loaded Polymeric Nanoparticles in Different Soil Systems: An Important Study on the Development of Safe Nanoherbicides

Nanoformulations have been used to improve the delivery of fertilizers, pesticides, and growth regulators, with a focus on more sustainable agriculture. Nanoherbicide research has focused on efficiency gains through targeted delivery and environmental risk reduction. However, research on the behavior and safety of the application of these formulations in cropping systems is still limited. Organic matter contained in cropping systems can change the dynamics of herbicide&ndash;soil interactions in the presence of nanoformulations. The aim of this study was to use classical protocols from regulatory studies to understand the retention and mobility dynamics of a metribuzin nanoformulation, compared to a conventional formulation. We used different soil systems and soil with added fresh organic material. The batch method was used for sorption&ndash;desorption studies and soil thin layer chromatography for mobility studies, both by radiometric techniques. Sorption parameters for both formulations showed that retention is a reversible process in all soil systems (H~1.0). In deep soil with added fresh organic material, nanoformulation was more sorbed (14.61 &plusmn; 1.41%) than commercial formulation (9.72 &plusmn; 1.81%) (p &lt; 0.05). However, even with the presence of straw as a physical barrier, metribuzin in nano and conventional formulations was mobile in the soil, indicating that the straw can act as a barrier to reduce herbicide mobility but is not impeditive to herbicide availability in the soil. Our results suggest that environmental safety depends on organic material maintenance in the soil system. The availability can be essential for weed control, associated with nanoformulation efficiency, in relation to the conventional formulation

Behavior aminocyclopyrachlor in function of the addition of organic material in soil

A matéria orgânica é um dos componentes mais influentes no comportamento de herbicidas aplicados via solo, podendo alterar a dinâmica destes compostos no ambiente. O objetivo deste estudo foi avaliar o efeito de solos alterados com palha de cana-de-açúcar, torta de filtro e vinhaça na sorção-dessorção, lixiviação, mineralização e degradação do aminoyclopyrachlor no solo. A sorção-dessorção foi verificada pelo método de equilíbrio em \"batch\", com os materiais orgânicos envelhecidos no solo (0, 15, 30 e 60 dias). A lixiviação foi realizada em colunas de vidro (200 mm em 48 horas) com as concentrações do herbicida aferidas no perfil do solo (0-0,30 m) e no lixiviado. A biodegradação foi conduzida por 112 dias, em frascos biométricos. A sorção do herbicida foi baixa para todos os tratamentos (Kd = 0,17-0,41 L kg-1), com dessorção de grande parte do herbicida aplicado. Menos de 2 % do herbicida esteve retido na palha e torta de filtro, com maior distribuição no perfil do solo. A vinhaça aumentou a lixiviação do herbicida (71 %) em relação aos demais materiais e o solo sem alteração (~50 %). A mineralização do aminocyclopyrachlor foi baixa (<45 % em 112 dias), havendo formação de ~30 % de resíduo ligado, sem a observação da formação de metabólitos ao longo do estudo. A meia-vida (DT50) no solo sem adição de material orgânico foi de 187 dias, com adição de materiais orgânicos chegou a 247-277 dias e 90 % de degradação foi estimada em 600-900 dias para todos os tratamentos. A presença de materiais orgânicos no solo promoveu maior disponibilidade do aminocyclopyrachlor em solução, principalmente para a lixiviação no perfil do solo, além de ter sua persistência aumentada no ambiente. A persistência do herbicida no ambiente favorece o controle mais prolongado de plantas daninhas, principalmente quando há maior disponibilidade no solo, porém no manejo deste herbicida em sistema de cana-de-açúcar, no qual há grande aporte de matéria orgânica no solo, podendo favorecer a contaminação de águas subterrâneasThe organic matter is one of the most influential components in the behavior of herbicides applied via soil, being able to alter the dynamics of these compounds in the environment. The objective of this study was to evaluate the effect of altered soils with sugarcane straw, filter cake and vinasse on sorption-desorption, leaching, mineralization and degradation of aminocyclopyrachlor in soil. Sorption-desorption was verified by the batch equilibrium method, with organic materials aged in the soil (0, 15, 30 and 60 days). The leaching was carried out in glass columns (200 mm in 48 hours) with the herbicide concentrations measured in the soil profile (0-0.30 m) and in the leachate. Biodegradation was conducted for 112 days in biometric vials. The sorption of the herbicide was low for all treatments (Kd = 0.17-0.41 L kg-1), with desorption of a large part of the herbicide applied. Less than 2 % of the herbicide was retained in straw and filter cake, with greater distribution in the soil profile. Vinasse increased herbicide leaching (71 %) in relation to other materials and soil without change (~ 50 %). Mineralization of aminocyclopyrachlor was low (<45 % in 112 days), with ~ 30 % formation of bound residue without observation of metabolite formation throughout the study. The half-life (DT50) in the soil without addition of organic material was 187 days, with addition of organic materials reached 247-277 days and 90 % degradation was estimated at 600-900 days for all treatments. The presence of organic materials in the soil promoted greater availability of aminocyclopyrachlor in solution, mainly for the leaching, besides having its persistence increased in the environment. The persistence of the herbicide in the environment favors the longer control of weeds, especially when there is greater availability in the soil, but in the management of this herbicide in a sugar cane system, in which there is a great contribution of organic matter in the soil, may favor the contamination of groundwate

Opinion: Hybrid nanoparticle systems – Two-way delivery approach for agriculture

Nanometric carriers have great potential for promoting agrochemical target delivery and dose reduction while transforming agriculture into a more sustainable environment. Many nanoplatforms, such as metal, polymeric, clay, and carbon-based, are developed differently. However, new possibilities of a mixture between nanomaterials are explored by scientists called hybrid nanoparticles. The information about these nanosystems was focused on development and characterization, target and non-target effects, and uptake of nanoparticles applied to reach root or foliar pathways in plants. In this scenario, a lack of application possibilities exists and can be explored more in the future. Hybrid nanoparticles can be developed as smart carrier to deliver nanoparticles and agrochemicals in a two-way approach for uptake by root and foliar routes simultaneously in plants. The advance of nanocarrier strategies depends on the design of nanoparticles considering nanomaterial and agrochemical characteristics and target plants. The main gaps and recent reports are discussed here. Furthermore, platforms have been suggested to enable two-way delivery for agricultural applications in more sustainable farming systems