Ecotoxicological effects of commercial herbicides on the reproductive system of aquatic arthropod Limnocoris submontandoni (Hemiptera: Naucoridae) / Efeitos ecotoxicológicos de herbicidas comerciais no sistema reprodutivo do artrópode aquático Limnocoris submontandoni (Hemiptera: Naucoridae)

Abstract Worldwide, conventional agriculture makes extensive use of pesticides. Although the effects of herbicides are relatively well known in terms of environmental impacts on non-target organisms, there is very little scientific evidence regarding the impacts of herbicide residues on aquatic arthropods from tropical conservation areas. This study evaluates for the first time the toxicity of the herbicides ametryn, atrazine, and clomazone on the aquatic insect Limnocoris submontandoni (Hemiptera: Naucoridae). The lethal concentration (LC50) of herbicides was evaluated for these insects, as well as the effect of the herbicides on the insects' tissues and testicles. The estimated LC50 was 1012.41, 192.42, and 46.09 mg/L for clomazone, atrazine, and ametryn, respectively. Spermatocyte and spermatid changes were observed under the effect of atrazine, and effects on spermatogenesis were observed for some concentrations of clomazone, with apparent recovery after a short time. Our results provide useful information on the effects of herbicide residues in aquatic systems. This information can help minimize the risk of long-term reproductive effects in non-target species that have been previously overlooked in ecotoxicology studies.

Resumo Em todo o mundo, a agricultura convencional faz uso extensivo de pesticidas. Embora os efeitos dos herbicidas sejam relativamente bem conhecidos em termos de impactos ambientais em organismos não-alvo, há pouca evidência científica sobre os impactos de resíduos de herbicidas em artrópodes aquáticos de áreas de conservação tropicais. Este estudo avalia pela primeira vez a toxicidade dos herbicidas ametryn, atrazine e clomazone sobre o inseto aquático Limnocoris submontandoni (Hemiptera: Naucoridae). A concentração letal (LC50) de herbicidas foi avaliada para esses insetos, bem como o efeito dos herbicidas nos tecidos e testículos dos insetos. A LC50 estimada foi de 1012,41, 192,42 e 46,09 mg/L para clomazone, atrazine e ametryn, respectivamente. Alterações nos espermatócitos e espermátides foram observadas sob o efeito de atrazine, e efeitos na espermatogênese foram observados para algumas concentrações de clomazone, com aparente recuperação após um curto período de tempo. Nossos resultados fornecem informações úteis sobre os efeitos de resíduos de herbicidas em sistemas aquáticos. Essas informações podem ajudar a minimizar o risco de efeitos reprodutivos de longo prazo em espécies não-alvo que foram negligenciadas anteriormente em estudos de ecotoxicologia.

Ecotoxicological effects of commercial herbicides on the reproductive system of aquatic arthropod Limnocoris submontandoni (Hemiptera: Naucoridae)

Abstract Worldwide, conventional agriculture makes extensive use of pesticides. Although the effects of herbicides are relatively well known in terms of environmental impacts on non-target organisms, there is very little scientific evidence regarding the impacts of herbicide residues on aquatic arthropods from tropical conservation areas. This study evaluates for the first time the toxicity of the herbicides ametryn, atrazine, and clomazone on the aquatic insect Limnocoris submontandoni (Hemiptera: Naucoridae). The lethal concentration (LC50) of herbicides was evaluated for these insects, as well as the effect of the herbicides on the insects tissues and testicles. The estimated LC50 was 1012.41, 192.42, and 46.09 mg/L for clomazone, atrazine, and ametryn, respectively. Spermatocyte and spermatid changes were observed under the effect of atrazine, and effects on spermatogenesis were observed for some concentrations of clomazone, with apparent recovery after a short time. Our results provide useful information on the effects of herbicide residues in aquatic systems. This information can help minimize the risk of long-term reproductive effects in non-target species that have been previously overlooked in ecotoxicology studies.

Resumo Em todo o mundo, a agricultura convencional faz uso extensivo de pesticidas. Embora os efeitos dos herbicidas sejam relativamente bem conhecidos em termos de impactos ambientais em organismos não-alvo, há pouca evidência científica sobre os impactos de resíduos de herbicidas em artrópodes aquáticos de áreas de conservação tropicais. Este estudo avalia pela primeira vez a toxicidade dos herbicidas ametryn, atrazine e clomazone sobre o inseto aquático Limnocoris submontandoni (Hemiptera: Naucoridae). A concentração letal (LC50) de herbicidas foi avaliada para esses insetos, bem como o efeito dos herbicidas nos tecidos e testículos dos insetos. A LC50 estimada foi de 1012,41, 192,42 e 46,09 mg/L para clomazone, atrazine e ametryn, respectivamente. Alterações nos espermatócitos e espermátides foram observadas sob o efeito de atrazine, e efeitos na espermatogênese foram observados para algumas concentrações de clomazone, com aparente recuperação após um curto período de tempo. Nossos resultados fornecem informações úteis sobre os efeitos de resíduos de herbicidas em sistemas aquáticos. Essas informações podem ajudar a minimizar o risco de efeitos reprodutivos de longo prazo em espécies não-alvo que foram negligenciadas anteriormente em estudos de ecotoxicologia.

Arbuscular mycorrhizal fungi activity in the rhizosphere of tree seedlings subjected to residual herbicides / Atividade de fungos micorrízicos arbusculares na rizosfera de mudas de árvores submetidas a herbicidas residuais

Abstract Trees occurring on the margins of agricultural areas can mitigate damage from residual herbicides. Rhizospheric microbial activity associated with trees is one of the main remedial capacity indicators. The objective of this study was to evaluate the rhizospheric microbiological activity in tree species subjected to the herbicides atrazine and sulfentrazone via the rhizosphere. The experiment was designed in four blocks and a 6 × 3 factorial scheme. The first factor consisted of six tree species from Brazil and the second of atrazine, sulfentrazone, and water solutions. Four herbicide applications were performed via irrigation. The total dry mass of the plants, mycorrhizal colonization, number of spores, basal respiration of the rhizospheric soil, and survival rate of bioindicator plants after phytoremediation were determined. Trichilia hirta had higher biomass when treated with atrazine and sulfentrazone. Herbicides decreased the microbial activity in Triplaris americana and did not affect the microbiological indicators of Myrsine gardneriana, Schizolobium parahyba, and Toona ciliata. Fewer bioindicator plants survived in soil with Triplaris americana and sulfentrazone. Microbiological indicators were influenced in different ways between species by the presence of herbicides in the rhizosphere.

Resumo As árvores que ocorrem nas margens das áreas agrícolas podem mitigar os danos dos herbicidas residuais. A atividade microbiana rizosférica associada às árvores é um dos principais indicadores de capacidade corretiva. O objetivo deste trabalho foi avaliar a atividade microbiológica rizosférica em espécies arbóreas submetidas aos herbicidas atrazina e sulfentrazone via rizosfera. O experimento foi estruturado em quatro blocos e esquema fatorial 6 × 3. O primeiro fator consistiu em seis espécies de árvores do Brasil e o segundo em soluções de atrazine, sulfentrazone e água. Quatro aplicações de herbicidas foram realizadas via irrigação. Foram determinados a massa seca total das plantas, colonização micorrízica, número de esporos, respiração basal do solo rizosférico e taxa de sobrevivência de plantas bioindicadoras após fitorremediação. Trichilia hirta apresentou maior biomassa quando tratada com atrazina e sulfentrazone. Os herbicidas diminuíram a atividade microbiana em Triplaris americana e não afetaram os indicadores microbiológicos de Myrsine gardneriana, Schizolobium parahyba e Toona ciliata. Menos plantas bioindicadoras sobreviveram no solo com Triplaris americana e sulfentrazone. Os indicadores microbiológicos foram influenciados de formas distintas entre as espécies pela presença dos herbicidas na rizosfera.

Arbuscular mycorrhizal fungi activity in the rhizosphere of tree seedlings subjected to residual herbicides / Atividade de fungos micorrízicos arbusculares na rizosfera de mudas de árvores submetidas a herbicidas residuais

Trees occurring on the margins of agricultural areas can mitigate damage from residual herbicides. Rhizospheric microbial activity associated with trees is one of the main remedial capacity indicators. The objective of this study was to evaluate the rhizospheric microbiological activity in tree species subjected to the herbicides atrazine and sulfentrazone via the rhizosphere. The experiment was designed in four blocks and a 6 × 3 factorial scheme. The first factor consisted of six tree species from Brazil and the second of atrazine, sulfentrazone, and water solutions. Four herbicide applications were performed via irrigation. The total dry mass of the plants, mycorrhizal colonization, number of spores, basal respiration of the rhizospheric soil, and survival rate of bioindicator plants after phytoremediation were determined. Trichilia hirta had higher biomass when treated with atrazine and sulfentrazone. Herbicides decreased the microbial activity in Triplaris americana and did not affect the microbiological indicators of Myrsine gardneriana, Schizolobium parahyba, and Toona ciliata. Fewer bioindicator plants survived in soil with Triplaris americana and sulfentrazone. Microbiological indicators were influenced in different ways between species by the presence of herbicides in the rhizosphere.

As árvores que ocorrem nas margens das áreas agrícolas podem mitigar os danos dos herbicidas residuais. A atividade microbiana rizosférica associada às árvores é um dos principais indicadores de capacidade corretiva. O objetivo deste trabalho foi avaliar a atividade microbiológica rizosférica em espécies arbóreas submetidas aos herbicidas atrazina e sulfentrazone via rizosfera. O experimento foi estruturado em quatro blocos e esquema fatorial 6 × 3. O primeiro fator consistiu em seis espécies de árvores do Brasil e o segundo em soluções de atrazine, sulfentrazone e água. Quatro aplicações de herbicidas foram realizadas via irrigação. Foram determinados a massa seca total das plantas, colonização micorrízica, número de esporos, respiração basal do solo rizosférico e taxa de sobrevivência de plantas bioindicadoras após fitorremediação. Trichilia hirta apresentou maior biomassa quando tratada com atrazina e sulfentrazone. Os herbicidas diminuíram a atividade microbiana em Triplaris americana e não afetaram os indicadores microbiológicos de Myrsine gardneriana, Schizolobium parahyba e Toona ciliata. Menos plantas bioindicadoras sobreviveram no solo com Triplaris americana e sulfentrazone. Os indicadores microbiológicos foram influenciados de formas distintas entre as espécies pela presença dos herbicidas na rizosfera.

Arbuscular mycorrhizal fungi activity in the rhizosphere of tree seedlings subjected to residual herbicides

Abstract Trees occurring on the margins of agricultural areas can mitigate damage from residual herbicides. Rhizospheric microbial activity associated with trees is one of the main remedial capacity indicators. The objective of this study was to evaluate the rhizospheric microbiological activity in tree species subjected to the herbicides atrazine and sulfentrazone via the rhizosphere. The experiment was designed in four blocks and a 6 × 3 factorial scheme. The first factor consisted of six tree species from Brazil and the second of atrazine, sulfentrazone, and water solutions. Four herbicide applications were performed via irrigation. The total dry mass of the plants, mycorrhizal colonization, number of spores, basal respiration of the rhizospheric soil, and survival rate of bioindicator plants after phytoremediation were determined. Trichilia hirta had higher biomass when treated with atrazine and sulfentrazone. Herbicides decreased the microbial activity in Triplaris americana and did not affect the microbiological indicators of Myrsine gardneriana, Schizolobium parahyba, and Toona ciliata. Fewer bioindicator plants survived in soil with Triplaris americana and sulfentrazone. Microbiological indicators were influenced in different ways between species by the presence of herbicides in the rhizosphere.

Resumo As árvores que ocorrem nas margens das áreas agrícolas podem mitigar os danos dos herbicidas residuais. A atividade microbiana rizosférica associada às árvores é um dos principais indicadores de capacidade corretiva. O objetivo deste trabalho foi avaliar a atividade microbiológica rizosférica em espécies arbóreas submetidas aos herbicidas atrazina e sulfentrazone via rizosfera. O experimento foi estruturado em quatro blocos e esquema fatorial 6 × 3. O primeiro fator consistiu em seis espécies de árvores do Brasil e o segundo em soluções de atrazine, sulfentrazone e água. Quatro aplicações de herbicidas foram realizadas via irrigação. Foram determinados a massa seca total das plantas, colonização micorrízica, número de esporos, respiração basal do solo rizosférico e taxa de sobrevivência de plantas bioindicadoras após fitorremediação. Trichilia hirta apresentou maior biomassa quando tratada com atrazina e sulfentrazone. Os herbicidas diminuíram a atividade microbiana em Triplaris americana e não afetaram os indicadores microbiológicos de Myrsine gardneriana, Schizolobium parahyba e Toona ciliata. Menos plantas bioindicadoras sobreviveram no solo com Triplaris americana e sulfentrazone. Os indicadores microbiológicos foram influenciados de formas distintas entre as espécies pela presença dos herbicidas na rizosfera.

The Effects of Triazine Herbicides on Critical Peroxide Metabolism Gene Expression in MCF-7 and MCF-10A Cells

Aim: To identify the oxidative stress impacts of chloro-s-triazine herbicides on human mammary epithelial cell lines.Study Design:MCF-7 mammary epithelial carcinoma and MCF-10A mammary epithelial cells were treated with levels of three triazine herbicides in concentrations flanking the US FDA safe levels. Place and Duration of Study:Department of Biology, Millikin University, in January 2015 through December 2015 and January 2019 through May 2020.Methodology:We examined the oxidative effects of two triazine herbicides, atrazine and simazine, on estrogen-dependent MCF-7 mammary epithelial carcinoma cells using three different bioluminescent assay techniques. We then utilized real time PCR to analyze gene expression through RT-PCR analysis, in both MCF-7 cells and a non-cancerous cell line, MCF-10A, for both of these triazine herbicides plus the related cyanazine.Results:At all concentrations of atrazine and simazine, no statistical differences were found in the levels of oxidized glutathione or total oxidized and reduced nicotinamide adenine dinucleotides phosphates. In stark contrast, levels of hydrogen peroxide were found tobe statistically different from the control at all concentrations of atrazine and simazine tested. Using an Analysis of Variance (ANOVA) we determined that within the enzymatic portion of the hydrogen peroxide pathway there were statistically significant differences in the expression of Peroxiredoxin 1 (PRDX1), Sulfiredoxin (SRXN1), and Thioredoxin (TXN).Conclusion:Exposure to triazines alters the hydrogen peroxide pathway, which in turn can greatly affect the stability of the cell milieu

Effects of weed management and plant arrangements on yield index of sweet sorghum / Eefeito do manejo de plantas daninhas e arranjo de plantas nos índices de produtividade do sorgo sacarino

Sweet sorghum is currently an important alternative for ethanol production in sugar cane off-season. In this study was to evaluate the effects of plant arrangements and the application of atrazine and S-metolachlor on growth and productivity of sweet sorghum. An experiment was conducted in randomized block design and, arranged in split plots with four repetitions. Plots consisted of spacing (0.25 m, 0.45 m 0.45-0.45-0.90 m) and sub-plots of weed control methods - atrazine (2000 g ha-1), atrazine + S-metolachlor (2000 + 720 g ha-1), atrazine + S-metolachlor (2000 + 960 g ha-1), atrazine + S-metolachlor (2000 + 1200 g ha-1), atrazine + S-metolachlor (2000 + 1440 g ha-1). Besides that, manual hoeing control was added. The intoxication of sorghum plants and weed control was evaluated at 7, 14 e 28 days after herbicides application (DAA). Plant height, stem diameter, total fresh matter, juice mass and total soluble solids (°Brix) were evaluated at 120 days after crop emergence (DAE). There was no interaction between the factors spacings and control method for variables total matter fresh (TMF), height (H), stem diameter (D), juice mass (JM), and Brix. Application of the mixture (atrazine + S-metolachlor) in the highest doses reduced total fresh matter and °Brix. The spacing of 0.25 m provided the highest productivity of fresh matter, juice mass and increased the °Brix. The application of mixture (atrazine + S-metolachlor) controlled 90% of the weeds at 28 days after application. The increasing in doses of S-metolachlor elevates the intoxication in sorghum plants. The mixture (atrazine + S-metolachlor) has a potential for use in weed control in sweet sorghum, but at doses below 960 g ha-1 of S-metolachlor.

O objetivo desse trabalho foi avaliar os efeitos de arranjos de plantas e dos herbicidas atrazine e S-metolachlor sobre o crescimento e a produtividade do sorgo sacarino. O experimento foi realizado no delineamento em blocos casualizados, com quatro repetições. Os tratamentos foram dispostos em esquema de parcelas subdivididas. Nas parcelas avaliaram-se os espaçamentos entrelinhas (0,25 m, 0,45 m e 0,45-0,45-0,90 m) e nas subparcelas os métodos de controle das plantas daninhas: atrazine (2000 g ha-1), atrazine + S-metolachlor (2000 + 720 g ha-1), atrazine + S-metolachlor (2000 + 960 g ha-1), atrazine + S-metolachlor (2000 + 1200 g ha-1), atrazine + S-metolachlor (2000 + 1440 g ha-1), capina manual e ausência de controle. Aos 7, 14 e 28 dias após a aplicação dos herbicidas foi avaliado a intoxicação das plantas de sorgo e o nível de controle de plantas daninhas na cultura. Aos 120 dias após a emergência da cultura avaliou-se altura de plantas, diâmetro de colmo, massa fresca total, massa de caldo e o teor de sólidos solúveis totais (Brix). Não houve interação entre os fatores espaçamentos e o método de controle para as variáveis massa fresca total (TMF), altura (H), diâmetro do caule (D), peso do suco (JM) e Brix. O controle das plantas daninhas e a intoxicação visual do sorgo aumentaram linearmente com o incremento das doses do S-metolachlor. O crescimento da cultura e os teores de Brix foram reduzidos pela aplicação da associação entre atrazine + S-metolachlor. A escolha do espaçamento de entrelinha influenciou nos componentes de rendimento da cultura. Conclui-se que, o espaçamento de 0,25 m de entrelinhas proporcionou maior produtividade de matéria fresca e de Brix do caldo. A associação entre atrazine e S-metolachlor tem potencial para o uso no controle de plantas daninhas em sorgo sacarino, em doses abaixo de 960 g ha-1 de S-metolachlor.

Desarrollo y capacidad de remoción de los pesticidas atrazina, clorpirifós y endosulfán por parte de cepas de Aspergillus sección Flavi no toxigénicas / Development and removal ability of non-toxigenic Aspergillus section Flavi in presence of atrazine, chlorpyrifos and endosulfan

This study evaluated the in vitro effect of three concentrations of atrazine, chlorpyrifos and endosulfan on the growth parameters of four non-toxigenic Aspergillus section Flavi strains. The ability of the strains to remove these pesticides in a synthetic medium was also determined. Growth parameters were measured on soil extract solid medium supplied with 5,10 and 20mg/l of each pesticide, and conditioned to -0.70, -2.78, -7.06 and -10.0 water potential (MPa). Removal assays were performed in Czapek Doc medium (CZD) supplied with 20mg/l of each pesticide under optimal environmental conditions (-2.78 of MPa and 25 °C). The residual levels of each pesticide were detected by the reversed-phase HPLC/fluorescence detection system. The lag phases of the strains significantly decreased in the presence of the pesticides with respect to the control media. This result indicates a fast adaptation to the conditions assayed. Similarly, the mycelial growth rates in the different treatments increased depending on pesticide concentrations. Aspergillus oryzae AM 1 and AM 2 strains showed high percentages of atrazine degradation (above 90%), followed by endosulfan (56 and 76%) and chlorpyrifos (50 and 73%) after 30 days of incubation. A significant (p <0.001) correlation (r = 0.974) between removal percentages and growth rate was found. This study shows that non-toxigenic Aspergillus section Flavi strains from agricultural soils are able to effectively grow in the presence of high concentrations of atrazine, chlorpyrifos and endosulfan under a wide range of MPa conditions. Moreover, these strains have the ability to remove high levels of these pesticides in vitro in a short time.

En este estudio se evaluó los efectos in vitro de 3 concentraciones de atrazina, clorpirifós y endosulfán sobre los parámetros de crecimiento de 4 cepas no toxigénicas de Aspergillus sección Flavi. También se evaluó la capacidad de las cepas de remover los pesticidas. Los parámetros de crecimiento se ensayaron en medio agar extracto de suelo suplementado con 5, 10 y 20mg/l de cada pesticida y acondicionado a -0.70, -2.78, -7.06 y -10.0 de potencial de agua (MPa). Los ensayos de remoción se realizaron en medio Czapek Dox con 20mg/l de cada pesticida bajo condiciones óptimas de crecimiento (-2.78 de MPa y 25 °C). Los niveles residuales de atrazina, clorpirifós y endosulfán se detectaron en un sistema HPLC con detección por fluorescencia. La fase de latencia de las cepas disminuyó significantemente en presencia de los pesticidas, indicando una rápida adaptación a dichas condiciones. La velocidad de crecimiento se incrementó considerablemente dependiendo de la concentración de pesticida. Las cepas Aspergillus oryzae AM1 y AM2 mostraron porcentajes elevados de degradación de atrazina (aproximadamente el 90%), seguidos por endosulfán (56 y 76%) y clorpirifós (50 y 73%). Se observó una correlación (r = 0.974) significante (p <0.001) entre el porcentaje de pesticida removido y la velocidad de crecimiento. Este estudio muestra que cepas no-toxigénicas de Aspergillus sección Flavi aisladas de suelos agrícolas desarrollan eficientemente en presencia de altas concentraciones de atrazina, clorpirifós y endosulfán en un amplio rango de MPa. Además, presentan capacidad de remover in vitro altos niveles de pesticidas en corto tiempo.

Exposure to Atrazine Elicits Morpho-Physiological and Testicular Dysfuntions in adult male rats

@#Some of the environmental toxicants acting as endocrine disruptors have been associated with health hazards in human and wildlife by modulating hormonal actions. The widely used herbicide; atrazine (ATZ) is a potent endocrine and testicular disruptor. However, studies on it remain largely inconclusive especially whether the effects are reversible or permanent. We therefore designed this study to evaluate the histological and hormonal changes associated with differential ATZ exposure. Twenty (20) adult male Wistar rats were divided into 4 groups (5 rats per group) control and three experimental groups. Control received the vehicle; the 3 groups received ATZ, 38.5, 77.0 and 154.0 mg/kg bw/day for 30 days respectively. The effects of Atrazine were assessed through histopathological observation, spermatozoa quality examination and reproductive hormone levels. Results showed that irrespective of the ATZ dose, there was significant decrease in weight, severe pathological changes in testicular tissue, decrease in the quality of semen and altered luteinizing hormone (LH) of the rats. Taken together, our findings showed that ATZ exposure could lead to poor reproductive ability in male Wistar rats

Immunotoxicity of herbicide atrazine and its effect on immune function of rats / 吉林大学学报(医学版)

Objective: To detecet the effect of herbicide atrazine (ATR) on immunologic function of the rats, and to clarify the immunotoxicity of ATR. Methods: A total of 32 Wistar rats were randomly divided into control group, low, middle and high doses of ATR groups (ra=8); the rats in various groups were given 0, 5, 25, and 125 mg · kg-1 ATR for 28 d, respectively. The body weights and spleen indexes of the rats in various groups were detected; HE staining was used to observe the morphology of spleen tissue of the rats in various groups; lymphocyte transformation assay was used to determine the lymphocyte transformation rates in spleen cells of the rats in various groups; the killing activities of NK cells in spleen cells of the rats in various groups were detected; flow cytometry was used to detect the percentages of CD3 and CD8 1 T cells in spleen cells of the rats in various groups; ELISA assay was used to detect the serum levels of interleukin-1 (IL-1) and interleukin-6 (IL-6) of the rats in various groups. Results: Compared with control group, the body weights of the rats in different doses of ATR groups had no statistically significant differences (P>0. 05). Compared with control group, the spleen indexes of the rats in low and middle doses of ATR groups had no statistically significant differences (P>0. 05), and the spleen index of the rats in high dose of ATR group was decreased (P0. 05). The spleen lymphocyte transformation assay results showed that compared with control group, the lymphocyte transformation rates of spleen cells of the rats in low and middle doses of ATR groups had no significant differences (P>0. 05); the lymphocyte transformation rate of spleen cells of the rats in high dose of ATR group was decreased (P0. 05), and the percentages of CD3 1 and CD8 1 T cells of the rats in high dose of ATR group were decreased (P0. 05), and the serum levels of IL-1 and IL-6 of the rats in high dose of ATR group were increased (P<0. 05). Conclusion: High dose of ART can induce the obvious immunotoxicity.

High sensitive ELISA for detection of atrazion / 中国应用生理学杂志

OBJECTIVES@#To set up ELISA for detection of atrazine with high precision.@*METHODS@#The reaction condition of indirect-ELISA was optimized, including atrazine-ovalbumin(AT-OVA) concentration and primary antibody concentration, organic solvent, goat anti-rat immunoglobin G-horseradish peroxidase(IgG-HRP) concentration. The actual samples were detected by the ELISA method established in our laboratory. Then the ELISA method was compared with the HPLC.@*RESULTS@#The specification curve of indirect-ELISA was set up after optimization. The relation coefficient R=0.9958. The limit of detection (LOD) was 1.972 ng/ml. The percent recovery of the actual samples was in range of 80%~120%. The ELISA detection sensitivity was higher than the HPLC in the range of 0 ng/ml~6 ng/ml atrazine.@*CONCLUSIONS@#The ELISA to detect atrazine has good specificity and high precision. And it can be applied in testing real atrazine samples replacing of the large-scale instrument.

Presença e remoção de atrazina, desetilatrazina, desisopropilatrazina e desetilhidroxiatrazina em instalação piloto de ozonização e filtração lenta / The presence and the removal of atrazine, deethylatrazine, deisopropylatrazine and deethylhidroxiatrazine in a pilot plant consisted of ozonation and slow sand filtration

RESUMO Os agrotóxicos, quando utilizados no meio ambiente, sofrem transformações bióticas e abióticas, gerando subprodutos com toxicidade maior ou semelhante ao agrotóxico de origem. No presente estudo foi investigada a dinâmica da presença de atrazina e seus produtos de degradação clorados, desisopropilatrazina e desetilhidroxiatrazina, na oxidação com ozônio, na filtração lenta em areia e na associação dos dois processos em instalação piloto. Foram estudadas as doses de ozônio de 0,9, 1,6 e 2,8 mg.L-1 para concentração de atrazina no afluente, variando de 30 a 79 µg.L-1. Para dose de ozônio de 2,8 mg.L-1, a concentração de atrazina foi inferior a 2 µg.L-1; no entanto, ocorreu formação de subprodutos em concentração superior a 3 µg.L-1. Na filtração lenta, não ocorreu redução da concentração de atrazina. Quando precedida da ozonização, para dose de 1,6 mg.L-1, a concentração de atrazina foi inferior a 2 µg.L-1 e atendeu ao valor máximo permitido pela Portaria MS 2.914/2011; entretanto, a concentração de subprodutos foi superior a 18 µg.L-1. Para dose de 2,8 mg.L-1, o valor de atrasina no efluente filtrado foi inferior a 0,1 µg.L-1, porém a somatória dos subprodutos clorados foi igual a 3,7 µg.L-1, ocorrendo comprometimento sanitário do efluente filtrado. A avaliação da remoção da atrazina em processos que utilizam a ozonização deve sempre estar associada ao monitoramento dos subprodutos clorados, principalmente o desetilatrazina, considerando que ocorre formação desses em concentração superior à da atrazina, produzindo água para abastecimento com elevado risco sanitário, e esses não constam da Portaria MS 2.914/2011.

ABSTRACT Pesticides suffer biotic and abiotic transformations when used in the environment, generating byproducts with toxicity greater than or similar to the original pesticide. In this study the dynamics of the presence of atrazine and its degradation products and chlorinated deisopropylatrazine and deethylhidroxiatrazine oxidation with ozone, in the slow filtration and the association of the two processes in pilot plant were investigated. Ozone dose of 0.9, 1.6 and 2.8 mg.L- 1 were studied for atrazine in the influent concentration ranging 30 a 79 µg.L-1. For ozone dose of 2.8 mg.L-1 atrazine concentration was less than 2 µg.L-1; however, formation of byproducts occurred at a concentration greater than 3 µg.L-1. In slow sand filtration only, there was no reduction in the concentration of atrazine. When preceded by ozonation, dose of 1.6 mg.L-1, the concentration of atrazine was less than 2 µg.L-1 and met the maximum value allowed by the Portaria 2,914/2011; however, the concentration of byproducts was over 18 µg.L-1. For ozone dose of 2.8 mg.L-1, atrazine value in the filtered effluent was less than 0.1 µg.L-1, but the sum of chlorinated byproducts was equal to 3.7 µg.L-1. The assessment of the removal of atrazine in processes using ozonation should always be associated with the monitoring of chlorinated byproducts, especially deethylatrazine considering that: there is formation of those in higher concentration of atrazine producing water supply with a high health risk and those not included in Portaria MS 2,914/2011.

Simultaneous Extraction of Atrazine and Its Toxic Metabolites Based on Functionalized Polyacrylonitrile Nanofiber Mat / 分析化学

A novel solid-phase extraction (SPE) adsorbent for simultaneous extraction of atrazine (ATZ) and its metabolites, deisopropylatrazine (DIA) and deethylatrazine (DEA) from environmental water samples was prepared. Polyacrylonitrile nanofibers (PAN NFs) mat was prepared via electrospinning, and was further functionalized to obtain polypyrrole modified polyacrylonitrile nanofibers (PPy-PAN NFs) mat, hydrazine modified polyacrylonitrile nanofibers (NH2-PAN NFs) mat and carboxyl modified polyacrylonitrile (COOH-PAN NFs) mat. The results showed that the adsorption capacity of COOH-PAN NFs mat was better than other three NFs mats in both static (2.0 mg/g) and dynamic (0.19 mg/g) experiments. Meanwhile, the runoff ratios of COOH-PAN NFs mat were the lowest (less than 30.0％) in the adsorption of three analytes, especially for high polar analytes, which showed that the hydrogen bond between carboxyl groups and analytes was the main interactive force. A combination of mat-based SPE and high performance liquid chromatography-diode array detection was further established for determination of 3 analytes in environmental water samples. The recoveries were 81.4％-120.3％ and the limits of detection were 0.12 ng/mL for DIA, 0.09 ng/mL for DEA and ATZ, respectively.

Influence of pH, temperature and nutrient addition on the degradation of atrazine by Nocardioides spp. isolated from agricultural soil in Nigeria

Aims: To effectively exploit the atrazine degrading capabilities of Nocardioides spp. isolated from agricultural soil samples in Nigeria and ascertain the effect of pH, temperature and nutrient addition on the degradation process. Methodology and results: Isolates were cultivated on atrazine mineral salts medium at a temperature range of 4 °C - 45 °C and a pH range of 3-10. An optimum atrazine degrading activity was observed in the isolates between temperatures of 25 °C and 37 °C and between pH 5 and 8. Different carbon sources (glycerine, glucose, chitin, cellulose and sodium citrate) and nitrogen sources (urea, biuret, cyanuric acid, potassium nitrate and ammonium chloride) were also added to the medium. The addition of carbon and nitrogen sources did not increase degradation rates although urea and glycerine repressed the degradation ability of the isolates. Statistical analyses of variance at P < 0.05 showed no significant differences in the growth and degradation rates by both bacterial isolates under these conditions. Conclusion, significance and impact study: Atrazine degradation by Nocardioides spp. is pH and temperature dependent, and requires no additional sources of carbon and nitrogen. Hence, its use in bioremediation of atrazine contaminated agricultural soil should be explored.

Performance of herbicides in sugarcane straw / Dinâmica de herbicidas em palha de cana-de-açúcar

The process of mechanical harvesting of sugarcane generates a large deposition of straw on the soil surface, providing a coverage that several studies have found important for reducing the weed population. Although such coverage reduces weed infestations, additional management, including chemical control, is still needed. Thus, this study aimed to evaluate the leaching of atrazine, pendimethalin, metribuzin, clomazone, diuron and hexazinone in sugarcane straw. The experiment was conducted at the School of Agronomic Engineering at UNESP (Sao Paulo State University) - Botucatu/SP. The sugarcane straw was collected in the field, cut and placed in quantities of 10t ha-1 in the capsules used as experimental units. The experimental design was completely randomized, using six herbicide treatments and four replications. Within 24 hours after the herbicides were applied in capsules with straw, five different rainfalls (5, 10, 20, 50 and 100mm) were simulated. The leached water was collected for chromatographic analysis. The herbicide percentages that crossed the straw layer were statistically correlated with the rainfall amount by the Mitscherlich model that compares the facility of herbicide removal from sugarcane straw. In summary, pendimethalin did not present quantified transposition of the product by sugarcane straw even with a rain simulation of 100 mm. Furthermore, two different profiles of facility to transpose the herbicides in straw were found: one for metribuzin and hexazinone that crossed quickly through the straw layer and another for atrazine, diuron and clomazone that required more rainfall to be leached from coverage to the soil according to the maximum removable amount of each herbicide.

O processo de colheita mecanizada de cana-de-açúcar gera uma grande quantidade de palhada depositada na superfície do solo e vários trabalhos destacam a importância da manutenção dessas coberturas em sistemas de cana crua, com destaque na redução da população de plantas daninhas. Mas, apesar de a cobertura vegetal reduzir a infestação das plantas daninhas, medidas complementares, como o controle químico, ainda são necessárias. Dessa forma, o objetivo deste estudo foi avaliar a transposição dos herbicidas atrazine, pendimethalin, metribuzin, clomazone, diuron e hexazinone em palha de cana-de-açúcar. O experimento foi desenvolvido na Faculdade de Ciências Agronômicas da UNESP - Botucatu/SP. A palha da cana-de-açúcar foi coletada em campo, cortada e colocada em quantidades de 10t ha-1 em recipientes plásticos utilizados como unidades experimentais. O delineamento experimental foi inteiramente casualisado, e foram testados seis tratamentos (atrazine, pendimethalin, metribuzin, clomazone, diuron e hexazinone) e quatro repetições. Nas cápsulas com palha e pulverizadas, foi realizado, no período de 24 horas após a aplicação, a simulação de diferentes lâminas de chuva (5, 10, 20, 50 e 100mm) e coletada a água lixiviada para posterior quantificação cromatográfica. Como análise estatística, os herbicidas foram correlacionados com as lâminas de chuva e foi usado o modelo de Mitscherlich para ajuste dos dados, que permitiu comparar a facilidade de remoção dos herbicidas pela palha. Em síntese, para o pendimethalin, não se observou transposição quantificada do produto pela palha de cana-de-açúcar, mesmo com uma lâmina de 100mm de chuva. Foram encontrados dois perfis diferentes de facilidade de transposição dos herbicidas em palha: um para o metribuzin e hexazinone, que passaram rapidamente pela camada de palha, e outro para atrazine, clomazone e diuron, que precisaram de uma quantidade superior de chuva para serem lixiviados da cobertura vegetal, em função da quantidade máxima removível dos herbicidas.

Toxic effects of atrazine on reproductive system of male rats / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>This study was designed to evaluate the toxic effects of Atrazine (ATZ) on the reproductive system of male rats.</p><p><b>METHODS</b>Male Sprague-Dawley rats were exposed to ATZ by gavage at dosages of 0, 38.5, 77, and 154 mg/kg bw/day for 30 d. The toxic effects of ATZ to rats were assessed through histopathologcal observation, spermatozoa quality evaluation, testicular marker enzyme indicators, antioxidant capacity and reproductive hormone levels.</p><p><b>RESULTS</b>Significant adverse effects on reproductive system were observed in rats exposed to ATZ at different dosages compared with 0 mg/kg group, including an irregular and disordered arrangement of the seminiferous epithelium in 154 mg/kg group; a decreased spermatozoa number and an increased spermatozoa abnormality rate in 77 and 154 mg/kg groups; decreased levels of acid phosphatase (ACP), alkaline phosphatase (AKP), lactic dehydrogenase (LDH), and succinate dehydrogenase (SDH) with the increasing of ATZ concentration; a decreased level of total antioxidant capacity (TAC) in a dose-dependent manner, and a decreased reduced glutathione (GSH) level and an increased malondialdehyde (MDA) content in 154 mg/kg group; and decreased serum levels of testosterone (T) and inhibin-B (INH-B) and an increased serum level of follicle stimulating hormone (FSH) in 77 and 154 mg/kg groups, and an increased serum level of luteinizing hormone (LH) in 154 mg/kg group.</p><p><b>CONCLUSION</b>These results suggested that relatively high doses of ATZ could exert reproductive toxicity of male rats.</p>

Atrazine degradation in liquid culture and soil by a novel yeast Pichia kudriavzevii strain Atz-EN-01 and its potential application for bioremediation.

A novel yeast strain, Atz-EN-01 isolated from contaminated-agricultural soil was found to be highly effective in degrading atrazine in liquid culture and soil. The molecular characterization based upon partial 18S rDNA and ITS regions identified the strain Atz-EN-01 as Pichia kudriavzevii. The yeast could degrade atrazine completely within 7 days with a rate constant of 0.31 per day following the first order kinetic model. The time in which initial atrazine concentration (500 mg/L) was reduced by 50% (half-life) was 2.2 days under optimal conditions (pH 7.0, temperature 30˚ C, inoculum size 3% (v/v) and shaking speed 120 rpm). The analysis of the metabolites using GC-MS identified the formation of 3 intermediates viz. hydroxyatrazine, N-isopropylammelide and cyanuric acid. The enzyme atrazine chlorohydrolase exhibited maximum activity during degradation. Based upon the intermediates identified by GC-MS and FT-IR analysis, the sequential process of atrazine degradation was proposed. In soil bioremediation experiment, inoculation of soil with Atz-EN-01 promoted effective degradation than did the control. To the best of our knowledge, this is the first report on Pichia kudriavzevii strain Atz-EN-01 which can serve as a potential agent for in-situ bioremediation of atrazine contaminated environment.

Emprego do carvão ativado para remoção de atrazina em água de abastecimento público / Using activated carbon for atrazine removal from public water supply

A atrazina é um dos herbicidas mais utilizados no mundo, sendo encontrada em águas superficiais e subterrâneas. Pertence à classe das s-triazinas, possui potencial carcinogênico e apresenta toxicidade como disruptor endócrino. A reconhecida limitação dos processos de tratamento de água, os quais empregam a coagulação química na remoção da atrazina e os efeitos na saúde, motivou este trabalho, considerando a adsorção em carvão ativado como tecnologia alternativa. O estudo experimental consistiu na caracterização física do carvão ativado e nos ensaios de adsorção em águas de diferentes conteúdos orgânicos. Foi possível verificar a capacidade do carvão ativado em remover atrazina, e o mecanismo de adsorção foi influenciado pela variação da qualidade das matrizes de água gerando isotermas com características distintas.

Atrazine is one of the most widely herbicides used in the world, being found in surface water and groundwater. It belongs to the s-triazines class classified as possible carcinogenic potential and toxicity presents as an endocrine disruptor. The acknowledged limitation of the water treatment processes, which employ chemical coagulation in atrazine removal and the risks to health, has motivated this work taking into regards the adsorption of activated carbon as an alternative technology. The experimental study consisted of physical characterization of activated carbon and of adsorption tests in waters of different organic content. It was possible to verify the capacity of activated carbon to remove atrazine, and the adsorption mechanism was influenced by the quality variation of water matrices generating isotherms with different characteristics.

Remoção de atrazina e metabólitos pela filtração lenta com leito de areia e carvão ativado granular / Removal of atrazine and metabolites through slow filtration by sand and granular activated carbon

A atrazina (ATZ)é um herbicida largamente utilizado no mundo, sendo encontrada associada aos seus produtos de degradação em águas superficiais e subterrâneas. Pertence à classe das s-triazinas e, juntamente com os metabólitos clorados deetilatrazina (DEA) e deisopropilatrazina (DIA), possui potencial carcinogênico e toxicidade como disruptores endócrinos. A limitação dos processos que empregam a coagulação química na remoção de ATZ, a conhecida capacidade do carvão ativado em remover microcontaminantes em água e o risco que a ATZ e seus metabólitos apresentam à saúde motivaram o estudo da filtração lenta com leito de areia e carvão ativado granular. Os resultados apontaram a eficiência do processo de filtração lenta com camada intermediária de carvão ativado granular na remoção de ATZ e a limitação deste na remoção dos metabólitos DEA, DIA e deetilhidroxiatrazina (DEHA).

Atrazine (ATZ) is widely used as herbicide, commonly found in association to its degradation products in surface water and groundwater. It belongs to the class of s-triazines and together with the chlorinated metabolites dieethylatrazine (DEA) and deisopropilatrazine (DIA) have carcinogenic potential and toxicity as endocrine disruptors. The limitation of the processes employing chemical coagulation in the removal of atrazine, the known ability of activated carbon to remove microcontaminants in water and the risk that atrazine and the potential toxicity to human health of its metabolits motivated the study of slow sand filtration bed combined with granular activated carbon. The results showed the high efficiency of the slow filtration process with intermediate layer of granular activated carbon in the removal of atrazine and its limitation on the removal of the metabolites DEA, DIA and diethylhidroxiatrazine (DEHA).

Adsorption of atrazine on selected vertisols and alfisols.

Adsorption of atrazine was studied on two Vertisols and two Alfisols varying in their physicochemical properties. Soils were equilibrated with various concentrations of atrazine using batch techniques. Adsorption affinity for atrazine was approximated by Freundlich constant (Kf), which is a measure of the strength or degree of adsorption. Kd values were calculated for atrazine despite some non-linearity in adsorption on both Vertisols and Alfisols. The Kd values are greater for Vertisols than Alfisols and increased with organic carbon content. Correlations were worked out between extent of adsorption and soil properties and were positively correlated with organic carbon (r = 0.688), clay content ( r = 0.712) and clay + organic carbon (r = 0.708). KOC values were calculated taking into account the organic carbon content for both Vertisols and Alfisols.