Science.gov

Sample records for alachlor atrazine butachlor

  1. Erythema multiforme major due to occupational exposure to the herbicides alachlor and butachlor.

    PubMed

    Kim, Hoon; Min, JinHong; Park, JungSoo; Lee, SukWoo; Lee, JiYeonn

    2011-02-01

    Alachlor and butachlor are commonly used chloroacetanilide herbicides. They are cytotoxic, but there have been rare reported cases of alachlor or butachlor induced erythema multiforme major. We report the case of a 38-year-old farmer with erythema multiforme major due to the occupational exposure to alachlor/butachlor. The patient presented to the ED because of itching. Confluent erythematous to violaceous maculopatches with bullae and erosions were seen on the trunk, both upper extremities and both lower extremities. He had no relevant past or family history of a similar skin disease. He had used alachlor/butachlor for 3 days before he developed the itch. We performed a skin incisional biopsy and found diffuse hydropic degeneration with many necrotic keratinocytes in the epidermis and mild to moderate superficial perivascular lymphocytic infiltrate admixed with neutrophils and eosinophils in the upper dermis. These results confirmed the diagnosis of erythema multiforme major. The patient was admitted and received systemic and topical steroids. After 18 days, most lesions had healed, and he was discharged.

  2. Atrazine, alachlor, and cyanazine in a large agricultural river system

    USGS Publications Warehouse

    Schottler, S.P.; Eisenreich, Steven J.; Capel, P.D.

    1994-01-01

    Atrazine, alachlor, and cyanazine exhibited maximum concentrations of about 1000-6000 ng/L in the Minnesota River in 1990 and 1991, resulting from precipitation and runoff following the application period. Transport of these herbicides to the river occurs via overland flow or by infiltration to tile drainage networks. Suspended sediment, SO42-, and Cl- concentrations were used as indicators of transport mechanisms. The atrazine metabolite, DEA, was present in the river throughout the year. The ratio of DEA to atrazine concentration was used to calculate an apparent first-order soil conversion rate of atrazine to DEA. Half lives of 21-58 d were calculated for 1990 and 1991, respectively. The longer conversion rate in 1991 results from rapid flushing from the soil and minimum exposure to soil microorganisms. Total flux of herbicide to the river was 1-6.5 t, with over 60% of this loading occurring during the month of June. Loading to the river accounts for less than 1.5% of applied herbicide. ?? 1994 American Chemical Society.

  3. Field-scale mobility and persistence of commercial and stargh-encapusulated atrazine and alachlor

    SciTech Connect

    Gish, T.J.; Shirmohammadi, A.; Wienhold, B.J.

    1994-03-01

    Recent laboratory studies have shown that starch-encapsulation (SE) may reduce leachate losses of certain pesticides. This study compares field-scale mobility and persistence of SE-atrazine [2-chloro-4-ethylamino-6-isopropylamino-s-triazine] and alachlor [2-chloro-N(2,6 diethylphenyl)-N-(methoxymethyl)acetamide] to that of a commerciall formulation (CF) of atrazine and alachlor. The research site consisted of four (0.25 ha) fields. Two fields were under no-tillage management (NT) and two were under conventional tillage (CT). One field in each tillage system received SE-formulated atritzine and alachlor, while the others received CF-atrazine and alachlor. Chemical movement and persistence was determined by analysis of surface samples ({approximately}3 cm) taken immediately after application and 1.1-m soil cores collected seven times over 2 yr. No significant difference in herbicide residue levels was observed between NT and CT, but there was a herbicide formulation effect. Soil residue analysis suggests that SE-atrazine was more persistent and less mobile than CF-atrazine. Starch- encapsulated-alachlor was slightly more persistent than CF-alachlor, but no differences in mobility between formulations was observed. The differential field behavior between SE-herbicides is attributed to the faster release of alachlor from the starch granules. Increased atrazine persistence was attributed to the reduction of leachate losses. The reduction in atrazine leaching is likely due to the slow release from the starch granules and subsequent diffusion into the son matrix where it is less subject to preferential flow processes. 20 refs., 6 figs., 1 tab.

  4. Cytogenetic effects of alachlor and/or atrazine in vivo and in vitro

    SciTech Connect

    Meisner, L.F.; Roloff, B.D. ); Belluck, D.A. )

    1992-01-01

    The purpose of this study was to assess the cytogenetic effects of two commonly used herbicides, alachlor and atrazine, which are often found together in groundwater. Chromosome damage was examined in bone marrow cells of mice drinking water containing 20 ppm alachlor and/or 20 ppm atrazine, with an immunosuppressive dose of cyclophosphamide used as a positive control. Chromosome damage was also quantified in human lymphocytes. The in vitro study demonstrated dose related cytogenetic damage not associated with mitotic inhibition or cell death, with damage due to the alachlor-atrazine combination suggesting an additive model. The fact that the elevated mitotic index was associated with immune suppresion in the cyclophosphamide group suggests that death of cells with accumulated chromosomal aberrations resulted in increased bone marrow proliferation, so a higher fraction of cells examined were newer with less damage.

  5. Environmentally friendly formulations of alachlor and atrazine: preparation, characterization, and reduced leaching.

    PubMed

    Sánchez-Verdejo, Trinidad; Undabeytia, Tomás; Nir, Shlomo; Villaverde, Jaime; Maqueda, Celia; Morillo, Esmeralda

    2008-11-12

    Atrazine and alachlor formulations were designed by encapsulating the herbicide molecules into phosphatidylcholine (PC) vesicles, which subsequently were adsorbed on montmorillonite. PC and montmorillonite are classified as substances of minimal toxicological risk by the U.S. EPA. PC enhanced alachlor and atrazine solubilities by 15- and 18-fold, respectively. A 6 mM PC:5 g/L clay ratio was found as optimal for PC adsorption on the clay. Active ingredient contents of the PC-clay formulations ranged up to 8.6% for atrazine and 39.5% for alachlor. Infrared spectroscopy showed hydrophobic interactions of herbicide molecules with the alkyl chains of PC, in addition to hydrophilic interactions with the PC headgroup. Release experiments in a sandy soil showed a slower rate from the PC-clay formulations than the commercial ones. Soil column experiments under moderate irrigation and bioactivity experiments indicate that a reduction in the recommended dose of alachlor and atrazine can be accomplished by using PC-clay formulations.

  6. Acute toxicity of butachlor and atrazine to freshwater green alga Scenedesmus obliquus and cladoceran Daphnia carinata.

    PubMed

    He, Hongzhi; Yu, Jing; Chen, Guikui; Li, Wenyang; He, Jinbo; Li, Huashou

    2012-06-01

    Both single and joint toxicity of atrazine and butachlor to freshwater green alga Scenedesmus obliquus and cladoceran Daphnia carinata isolated from South China were investigated in the present study. The 96 h-EC(50) values of atrazine and butachlor to S. obliquus were 0.0147 and 2.31 mg L(-1), while the 48 h-LC(50) values to D. carinata were 60.6 and 3.40 mg L(-1), respectively. These results suggest that atrazine could be highly toxic to S. obliquus and slightly toxic to D. carinata, while butachlor exhibits moderate toxicity to both organisms. The additive indexes of atrazine and butachlor mixtures were -2.68 (-3.02 to -2.32) to S. obliquus and 0.054 (-0.025 to 0.238) to D. carinata, respectively. Therefore, the joint action of two herbicides was significant antagonism to S. obliquus, while significant synergism was not shown to D. carinata. Moreover, significant linear correlation between the natural logarithm of herbicide concentrations and growth rates of alga S. obliquus was observed. Taken together, it is the first study reporting the toxicity endpoints for mixture of atrazine and butachlor against S. obliquus and D. carinata isolated from south China. The present results would be helpful to provide data to assess the ecological risk of both herbicides to aquatic organisms.

  7. Alachlor

    Integrated Risk Information System (IRIS)

    Alachlor ; CASRN 15972 - 60 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  8. Transport of Alachlor, Atrazine, Dicamba, and Bromide through Silt and Loam Soils

    NASA Astrophysics Data System (ADS)

    Tindall, J. A.

    2015-12-01

    The herbicides alachlor, atrazine, and dicamba, as well as bromide were applied to soils overlying the High Plains aquifer in Nebraska, to both macropore and non-macropore sites. Three of 6 study areas (exhibiting a high percentage of macropores) were used for analysis of chemical transport. Twelve intact soil cores (30 cm diameter; 40 cm height), were excavated (two each from 0-40 cm and 40-80 cm depths). The first three study areas and soil cores were used to study preferential flow characteristics using dye staining and to determine hydraulic properties; the remaining cores were treated the same as field macropore sites. Two undisturbed experimental field plots, each with a 1 m2 surface area, were established in each of the three macropore study areas. Each preferential plot was instrumented with suction lysimeters, tensiometers, and neutron access tubes - 10 cm increments to 80 cm - and planted in corn. Three study areas that did not exhibit macropores had alachlor, atrazine, and dicamba and bromide disked into the top 15 cm of soil; concentrations were tracked for 120 days - samples were collected on a grid, distributed within 3 plots measuring 50 m x 50 m each. Core samples were collected prior to and immediately after application, and then at 30, 60, and 120 days after application. Each lab core sample was in 15-cm lengths from 0-15 cm, 15-30 cm, 45-60 cm, and 75-90 cm. For areas exhibiting macropores, herbicides had begun to move between 10-15 days after application with concentrations peaking at various depths after heavy rainfall events. Field lysimeter samples showed increases in concentrations of herbicides at depths where laboratory data indicated greater percentages of preferential flowpaths. Concentrations of atrazine, alachlor and dicamba exceeding 0.30, 0.30, and 0.05 μg m1-1 respectively were observed with depth (10-30 cm and 50-70 cm) after two months following heavy rainfall events indicating that preferential flowpaths were a significant

  9. RESPONSES OF MOLECULAR INDICATORS OF EXPOSURE IN MESOCOSMS: COMMON CARP (CYPRINUS CARPIO) EXPOSED TO THE HERBICIDES ALACHLOR AND ATRAZINE

    EPA Science Inventory

    Common carp (Cyprinus carpio) were treated in aquatic mesocosms with a single pulse of the herbicides atrazine or alachlor to study the bioavailability and biological activity of these herbicides using molecular indicators: Liver vitellogenin gene expression in male fish for estr...

  10. Responses of molecular indicators of exposure in mesocosms: common carp (Cyprinus carpio) exposed to the herbicides alachlor and atrazine.

    PubMed

    Chang, Lina W; Toth, Gregory P; Gordon, Denise A; Graham, David W; Meier, John R; Knapp, Charles W; deNoyelles, F Jerry; Campbell, Scott; Lattier, David L

    2005-01-01

    Common carp (Cyprinus carpio) were treated in aquatic mesocosms with a single pulse of the herbicides atrazine or alachlor to study the bioavailability and biological activity of these herbicides using molecular indicators: Liver vitellogenin gene expression in male fish for estrogenic activity, liver cytochrome P4501A1 gene expression, and DNA damage in blood cells using the single-cell gel electrophoresis method. Both alachlor and atrazine showed dose-related increases in DNA strand breaks at environmentally relevant concentrations (<100 ppb). Gene expression indicators showed that neither herbicide had estrogenic activity in the carp, whereas atrazine at concentrations as low as 7 ppb induced cytochrome P4501A1. These results support the study of molecular indicators for exposure in surrogate ecosystems to gauge relevant environmental changes following herbicide treatments.

  11. Simultaneous determination of alachlor, metolachlor, atrazine, and simazine in water and soil by isotope dilution gas chromatography/mass spectrometry

    SciTech Connect

    Huang, L.Q.

    1989-03-01

    A multiresidue method was developed for the simultaneous determination of low parts per billion (ppb) concentrations of the herbicides alachlor, metolachlor, atrazine, and simazine in water and soil using isotope dilution gas chromatography/mass spectrometry (GC/MS). Known amounts of /sup 15/N,/sup 13/C-alachlor and /sup 2/H/sub 5/-atrazine were added to each sample as internal standards. The samples were then prepared by a solid phase extraction with no further cleanup. A high resolution GC/low resolution MS system with data acquisition in selected ion monitoring mode was used to quantitate herbicides in the extract. The limit of detection was 0.05 ppb for water and 0.5 ppb for soil. Accuracy greater than 80% and precision better than 4% was demonstrated with spiked samples.

  12. Comparative sensitivity of five species of macrophytes and six species of algae to atrazine, metribuzin, alachlor, and metolachlor

    USGS Publications Warehouse

    Fairchild, James F.; Ruessler, Shane; Carlson, A. Ron

    1998-01-01

    This study determined the relative sensitivity of five species of aquatic macrophytes and six species of algae to four commonly used herbicides (atrazine, metribuzin, alachlor, and metolachlor). Toxicity tests consisted of 96-h (duckweed and algae) or 14-d (submerged macrophytes) static exposures. The triazine herbicides (atrazine and metribuzin) were significantly more toxic to aquatic plants than were the acetanilide herbicides (alachlor and metolachlor). Toxicity studies ranked metribuzin > atrazine > alachlor > metolachlor in decreasing order of overall toxicity to aquatic plants. Relative sensitivities of macrophytes to these herbicides decreased in the order of Ceratophyllum > Najas > Elodea > Lemna > Myriophyllum. Relative sensitivities of algae to herbicides decreased in the order of Selenastrum > Chlorella > Chlamydomonas > Microcystis > Scenedesmus > Anabaena. Algae and macrophytes were of similar overall sensitivities to herbicides. Data indicated that Selenastrum, a commonly tested green alga, was generally more sensitive compared to other plant species. Lemna minor, a commonly tested floating vascular plant, was of intermediate sensitivity, and was fivefold less sensitive than Ceratophyllum, which was the most sensitive species tested. The results indicated that no species was consistently most sensitive, and that a suite of aquatic plant test species may be needed to perform accurate risk assessments of herbicides.

  13. Relation of Landscape Position and Irrigation to Concentrations of Alachlor, Atrazine, and Selected Degradates in Regolith in Northeastern Nebraska

    USGS Publications Warehouse

    Verstraeten, Ingrid M.; Lewis, D.T.; McCallister, D.L.; Parkhurst, A.; Thurman, E.M.

    1996-01-01

    Concentrations of alachlor, its ethanesulfonic acid degradate, atrazine and its degradates, deethylatrazine and deisopropylatrazine, in the upper regolith and associated shallow aquifers were determined in relation to landscape position (floodplains, terraces, and uplands) and irrigation (nonirrigated and irrigated corn cropland) in 1992. Irrigated and nonirrigated sites were located on each landscape position. Samples were collected from three depths. Canonical discriminant and multivariate analyses were used to interpret data. Herbicides and their degradation products tended to be present in soils with high percent organic matter, low pH, and low sand content. Atrazine was present more frequently on the floodplain at all depths than the other compounds. Atrazine (maximum 17.5 ??g/kg) and ethanesulfonic acid (maximum 10 ??g/kg) were associated with landscape position, but not with irrigation. Alachlor (maximum 24 ??g/kg), deethylatrazine (maximum 1.5 ??g/kg), and deisopropylatrazine (maximum 3.5 ??g/kg) were not significantly associated with either landscape position or irrigation. Ground-water analytical results suggested that concentrations of these herbicides and degradates in ground water did not differ among landscape position or between irrigated and nonirrigated corn cropland.

  14. Consensus diagnoses and mode of action for the formation of gastric tumors in rats treated with the chloroacetanilide herbicides alachlor and butachlor.

    PubMed

    Furukawa, Satoshi; Harada, Takanori; Thake, Daryl; Iatropoulos, Michael J; Sherman, James H

    2014-01-01

    A panel of pathologists (Panel) was formed to evaluate the pathogenesis and human relevance of tumors that developed in the fundic region of rat stomachs in carcinogenicity and mechanistic studies with alachlor and butachlor. The Panel evaluated stomach sections stained with hematoxylin and eosin, neuron-specific enolase, and chromogranin A to determine the presence and relative proportion of enterochromaffin-like (ECL) cells in the tumors and concluded all tumors were derived from ECL cells. Biochemical and pathological data demonstrated the tumor formation involved a nongenotoxic threshold mode of action (MOA) initially characterized by profound atrophy of the glandular fundic mucosa that affected gastric glands, but not surface epithelium. This resulted in a substantial loss of parietal cells and a compensatory mucosal cell proliferation. The loss of parietal cells caused a marked increase in gastric pH (hypochlorhydria), leading to sustained and profound hypergastrinemia. The mucosal atrophy, together with the increased gastrin, stimulated cell growth in one or more ECL cell populations, resulting in neoplasia. ECL cell autocrine and paracrine effects led to dedifferentiation of ECL cell tumors. The Panel concluded the tumors develop via a threshold-dependent nongenotoxic MOA, under conditions not relevant to humans.

  15. Runoff and leaching of atrazine and alachlor on a sandy soil as affected by application in sprinkler irrigation.

    PubMed

    Abdel-Rahman, A R; Wauchope, R D; Truman, C C; Dowler, C C

    1999-05-01

    Rainfall simulation was used with small packed boxes of soil to compare runoff of herbicides applied by conventional spray and injection into sprinkler-irrigation (chemigation), under severe rainfall conditions. It was hypothesized that the larger water volumes used in chemigation would leach some of the chemicals out of the soil surface rainfall interaction zone, and thus reduce the amounts of herbicides available for runoff. A 47-mm rain falling in a 2-hour event 24 hours after application of alachlor (2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)-acetamide) and atrazine (6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2, 4-diamine) was simulated. The design of the boxes allowed a measurement of pesticide concentrations in splash water throughout the rainfall event. Initial atrazine concentrations exceeding its' solubility were observed. When the herbicides were applied in 64,000 L/ha of water (simulating chemigation in 6.4 mm irrigation water) to the surface of a Tifton loamy sand, subsequent herbicide losses in runoff water were decreased by 90% for atrazine and 91% for alachlor, as compared to losses from applications in typical carrier water volumes of 187 L/ha. However, this difference was not due to an herbicide leaching effect but to a 96% decrease in the amount of runoff from the chemigated plots. Only 0.3 mm of runoff occurred from the chemigated boxes while 7.4 mm runoff occurred from the conventionally-treated boxes, even though antecedent moisture was higher in the former. Two possible explanations for this unexpected result are (a) increased aggregate stability in the more moist condition, leading to less surface sealing during subsequent rainfall, or (b) a hydrophobic effect in the drier boxes. In the majority of these pans herbicide loss was much less in runoff than in leachate water. Thus, in this soil, application of these herbicides by chemigation would decrease their potential for pollution only in situations where runoff is a greater

  16. Runoff and leaching of atrazine and alachlor on a sandy soil as affected by application in sprinkler irrigation.

    PubMed

    Abdel-Rahman, A R; Wauchope, R D; Truman, C C; Dowler, C C

    1999-05-01

    Rainfall simulation was used with small packed boxes of soil to compare runoff of herbicides applied by conventional spray and injection into sprinkler-irrigation (chemigation), under severe rainfall conditions. It was hypothesized that the larger water volumes used in chemigation would leach some of the chemicals out of the soil surface rainfall interaction zone, and thus reduce the amounts of herbicides available for runoff. A 47-mm rain falling in a 2-hour event 24 hours after application of alachlor (2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)-acetamide) and atrazine (6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2, 4-diamine) was simulated. The design of the boxes allowed a measurement of pesticide concentrations in splash water throughout the rainfall event. Initial atrazine concentrations exceeding its' solubility were observed. When the herbicides were applied in 64,000 L/ha of water (simulating chemigation in 6.4 mm irrigation water) to the surface of a Tifton loamy sand, subsequent herbicide losses in runoff water were decreased by 90% for atrazine and 91% for alachlor, as compared to losses from applications in typical carrier water volumes of 187 L/ha. However, this difference was not due to an herbicide leaching effect but to a 96% decrease in the amount of runoff from the chemigated plots. Only 0.3 mm of runoff occurred from the chemigated boxes while 7.4 mm runoff occurred from the conventionally-treated boxes, even though antecedent moisture was higher in the former. Two possible explanations for this unexpected result are (a) increased aggregate stability in the more moist condition, leading to less surface sealing during subsequent rainfall, or (b) a hydrophobic effect in the drier boxes. In the majority of these pans herbicide loss was much less in runoff than in leachate water. Thus, in this soil, application of these herbicides by chemigation would decrease their potential for pollution only in situations where runoff is a greater

  17. Leaching of Br-, metolachlor, alachlor, atrazine, deethylatrazine and deisopropylatrazine in clayey vadoze zone: a field scale experiment in north-east Greece.

    PubMed

    Vryzas, Zisis; Papadakis, Emmanuel Nikolaos; Papadopoulou-Mourkidou, E

    2012-04-15

    An extensive four-year research program has been carried out to explore and acquire knowledge about the fundamental agricultural practices and processes affecting the mobility and bioavailability of pesticides in soils under semi-arid Mediterranean conditions. Pesticide leaching was studied under field conditions at five different depths using suction cups. Monitoring of metolachlor, alachlor, atrazine, deethylatrazine (DEA), deisopropylatrazine (DIA), and bromide ions in soil water, as well as dye patterns made apparent the significant role of preferential flow to the mobility of the studied compounds. Irrespective to their adsorption capacities and degradation rates, atrazine, metolachlor and bromide ions were simultaneously detected to 160 cm depth. Following 40 mm irrigation, just after their application, both alachlor and atrazine were leached to 160 cm depth within 18 h, giving maximum concentrations of 211 and 199 μg L(-1), respectively. Metolachlor was also detected in all depth when its application was followed by a rainfall event (50 mm) two weeks after its application. The greatest concentrations of atrazine, alachlor and metolachlor in soil water were 1795, 1166 and 845 μg L(-1), respectively. The greatest concentrations of atrazine's degradation products (both DEA and DIA) appeared later in the season compared to the parent compound. Metolachlor exhibited the greatest persistence with concentrations up to 10 μg L(-1) appearing in soil water 18 months after its application. Brilliant blue application followed by 40 mm irrigation clearly depict multi-branching network of preferential flow paths allowing the fast flow of the dye down to 150 cm within 24 h. This network was created by soil cracks caused by shrinking of dry soils, earthworms and plant roots. Chromatographic flow of the stained soil solution was evident only in the upper 10-15 cm of soil. PMID:22325931

  18. Combined toxicity of butachlor, atrazine and λ-cyhalothrin on the earthworm Eisenia fetida by combination index (CI)-isobologram method.

    PubMed

    Chen, Chen; Wang, Yanhua; Zhao, Xueping; Qian, Yongzhong; Wang, Qiang

    2014-10-01

    Pesticides in the environment do not appear singly and usually occur as complex mixtures and their combined effect may exhibit toxicity to organisms. The individual and combined toxicities of two herbicides, atrazine and butachlor and an insecticide λ-cyhalothrin have been examined to the earthworm Eisenia fetida, as a non-target terrestrial organism, in artificial soil and filter paper tests. The order of toxicity for the individual pesticides was ranked as atrazine>λ-cyhalothrin>butachlor in both tests. We applied the combination index (CI)-isobologram method which is widely used to study chemical interactions to determine the nature of toxicological interactions of the pesticides and it allows computerized quantitation of synergism, additive effect and antagonism. For most cases in artificial soil test, synergism was observed in majority of the mixtures except for the combination of butachlor plus λ-cyhalothrin. This particular combination displayed opposite interaction in filter paper test. The CI method was compared with the classical models of Concentration Addition (CA) and Independent Action (IA) and we found that CI method could accurately predict the combined toxicity and can serve as a useful tool in ecotoxicological risk assessment.

  19. A High-Performance Liquid Chromatography-Based Screening Method for the Analysis of Atrazine, Alachlor, and Ten of Their Transformation Products

    USGS Publications Warehouse

    Schroyer, B.R.; Capel, P.D.

    1996-01-01

    A high-performance liquid Chromatography (HPLC) method is presented for the for the fast, quantitative analysis of the target analytes in water and in low organic-carbon, sandy soils that are known to be contaminated with the parent herbicides. Speed and ease of sample preparation was prioritized above minimizing detection limits. Soil samples were extracted using 80:20 methanol:water (volume:volume). Water samples (50 ??L) were injected directly into the HPLC without prior preparation. Method quantification limits for soil samples (10 g dry weight) and water samples ranged from 20 to 110 ng/g and from 20 to 110 ??g/L for atrazine and its transformation products and from 80 to 320 ng/g and from 80 to 320 ??g/L for alachlor and its transformation products, respectively.

  20. Atrazine

    Integrated Risk Information System (IRIS)

    Atrazine ; CASRN 1912 - 24 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects

  1. Characterization of a Novel Butachlor Biodegradation Pathway and Cloning of the Debutoxylase (Dbo) Gene Responsible for Debutoxylation of Butachlor in Bacillus sp. hys-1.

    PubMed

    Gao, Yang; Jin, Lei; Shi, Hui; Chu, Zhangjie

    2015-09-30

    Bacillus sp. strain hys-1, which was isolated from active sludge, could degrade >90% butachlor at a concentration of 100 mg/L within 7 days. The present work revealed that strain hys-1 could mineralize butachlor via the following pathway: butachlor was initially metabolized to 2-chloro-N-(2,6-diethylphenyl)-N-methylacetamide by debutoxylation and then transformed to form 2-chloro-N-(2,6-diethylphenyl)acetamide by N-demethylation. Subsequently, it was converted to 2,6-diethylaniline and further mineralized into CO2 and H2O. In addition, the catalytic efficiency of crude cell extracts descended as follows: alachlor > acetochlor > butachlor. Furthermore, a novel 744 bp gene responsible for transforming butachlor into 2-chloro-N-(2,6-diethylphenyl)-N-methylacetamide was cloned from strain hys-1 and the encoding debutoxylase was designated Dbo. Then Dbo was expressed in Escherichia coli BL21 (DE3) and purified using Ni-nitrilotriacetic acid affinity chromatography. Dbo displayed the highest activity against butachlor at pH 6.5 and 30 °C. Metal ions played an important role in Dbo activity. To the best of the authors' knowledge, this is the first report that strain hys-1 can mineralize butachlor by a novel metabolic mechanism and the first identification of a gene encoding butachlor debutoxylase.

  2. Occurrence of alachlor and its sulfonated metabolite in rivers and reservoirs of the midwestern United States: The importance of sulfonation in the transport of chloroacetanilide herbicides

    USGS Publications Warehouse

    Thurman, E.M.; Goolsby, D.A.; Aga, D.S.; Pomes, M.L.; Meyer, M.T.

    1996-01-01

    Alachlor and its metabolite, 2-[(2',6'-diethylphenyl)- (methoxymethyl)amino]-2-oxoethanesulfonate (ESA), were identified in 76 reservoirs in the midwestern United States using immunoassay, liquid chromatography, and gas chromatography/mass spectrometry. The median concentration of ESA (0.48 ??g/L) exceeded the median concentration of alachlor (<0.05 ??g/L), with highest values in the upper Midwest. ESA also was detected in the Mississippi River from the mouth to the headwaters at concentrations of 0.2-1.5 ??g/L, exceeding the concentration of alachlor. In a field runoff study, alachlor rapidly formed ESA. It is hypothesized that a glutathione conjugate forms, which later oxidizes in soil to ESA. The removal of the chlorine atom lessens the toxicity of the parent compound and increases runoff potential. It is hypothesized further that sulfonic acid metabolites of other chloroacetanilides, including acetochlor, butachlor, metolachlor, and propachlor, also occur in surface water.

  3. Volatilization of alachlor from polymeric formulations.

    PubMed

    Dailey, Oliver D

    2004-11-01

    Pesticides may be dispersed throughout the environment by several means, including groundwater contamination, surface water contamination, and volatilization with subsequent atmospheric transport and deposition. In earlier research primarily directed at reducing the potential for groundwater contamination, a number of herbicides were microencapsulated within several different polymers. These polymeric formulations were evaluated for efficacy in the greenhouse. In the studies described in this paper, three polymeric alachlor formulations that were the most effective in the greenhouse were evaluated in laboratory volatility studies using pure alachlor and a commercial formulation (Lasso 4EC) for comparison purposes. In a given experiment, technical alachlor, Lasso 4EC, and two polymeric formulations were applied to soil and evaluated in a contained system under 53% humidity with a fixed flow rate. Evolved alachlor was collected in ethylene glycol, recovered with C18 solid phase extraction cartridges, and analyzed by reverse-phase high-performance thin-layer chromatography with densitometry. Duration of the studies ranged from 32 to 39 days. In studies in which all formulations were uniformly incorporated in the soil, total alachlor volatilization from the polymeric microcapsules was consistently lower than that from the alachlor and Lasso 4EC formulations. In studies in which the polymeric formulations were sprinkled on the surface of the soil, microcapsules prepared with the polymer cellulose acetate butyrate released the smallest quantity of volatilized alachlor.

  4. DNA adduct formation by alachlor metabolites

    SciTech Connect

    Brown, M.A.; Kimmel, E.C.; Casida, J.E.

    1988-01-01

    The extent of DNA adduct formation by alachlor (ArN(CH/sub 2/OCH/sub 3/)C(O)CH/sub 2/Cl wherein Ar is 2,6-diethylphenyl) and its metabolites is used as a guide to deduce the causal agent(s) in the carcinogenicity of this major herbicide. (/sup 14/C-phenyl)Alachlor is compared to its two metabolic cleavage products, (/sup 14/C-phenyl) 2-chloro-N-(2,6-diethylphenyl)acetamide (CDEPA) (ArNHC(O)CH/sub 2/Cl) and (/sup 14/C-phenyl)2,6-diethylaniline (DEA) (ArNH/sub 2/), and to (/sup 14/C-methoxy)alachlor in various in vitro and in vivo systems. Horseradish peroxidase and hydrogen peroxide activate DEA, but not CEDPA or alachlor, for formation of adducts with calf thymus DNA, which probably involves 2,6-diethylnitrosobenzene (ArNO) as an intermediate. Mouse liver microsomes and NADPH are both required to enhance the binding from each labeled preparation to calf thymus DNA; 4-fold higher labeling is observed from (/sup 14/C-methoxy)- than from (/sup 14/C-phenyl)alachlor. This 4-fold preferential DNA labeling from the /sup 14/C-methoxy compound is likewise found in the liver of mice treated intraperitoneally. Mouse liver protein and hemoglobin are also labeled, in vivo, with (/sup 14/C-phenyl)alachlor, -CDEPA and -DEA, and, as with the DNA, the labeling of these proteins is 1.5- to 2-fold higher with (/sup 14/C-methoxy)alachlor.

  5. Biodegradation of butachlor by Rhodococcus sp. strain B1 and purification of its hydrolase (ChlH) responsible for N-dealkylation of chloroacetamide herbicides.

    PubMed

    Liu, Hong-Ming; Cao, Li; Lu, Peng; Ni, Haiyan; Li, Yun-Xiang; Yan, Xin; Hong, Qing; Li, Shun-Peng

    2012-12-19

    Rhodococcus sp. strain B1 could degrade 100 mg/L butachlor within 5 days. Butachlor was first hydrolyzed by strain B1 through N-dealkylation, which resulted in the production of butoxymethanol and 2-chloro-N-(2,6-dimethylphenyl)acetamide. Butoxymethanol could be further degraded and utilized as the carbon source for the growth of strain B1, whereas 2-chloro-N-(2,6-dimethylphenyl)acetamide could not be degraded further. The hydrolase designated ChlH, responsible for the N-dealkylation of the side chain of butachlor, was purified 185.1-fold to homogeneity with 16.1% recovery. The optimal pH and temperature of ChlH were observed to be 7.0-7.5 and 30 °C, respectively. This enzyme was also able to catalyze the N-dealkylation of other chloroacetamide herbicides; the catalytic efficiency followed the order alachlor > acetochlor >butachlor > pretilachlor, which indicated that the alkyl chain length influenced the N-dealkylation of the chloroacetamide herbicides. This is the first report on the biodegradation of chloroacetamide herbicides at the enzyme level.

  6. Occurrence of Atrazine and Related Compounds in Sediments of Upper Great Lakes.

    PubMed

    Guo, Jiehong; Li, Zhuona; Ranasinghe, Prabha; Bonina, Solidea; Hosseini, Soheil; Corcoran, Margaret B; Smalley, Colin; Kaliappan, Rajashankar; Wu, Yan; Chen, Da; Sandy, Andy L; Wang, Yawei; Rockne, Karl J; Sturchio, Neil C; Giesy, John P; Li, An

    2016-07-19

    Surface grab and core sediment samples were collected from Lakes Michigan, Superior, and Huron from 2010 to 2012, and concentrations of herbicides atrazine, simazine, and alachlor, as well as desethylatrazine (DEA), were determined. Concentrations of atrazine in surface grabs ranged from 0.01 to 1.7 ng/g dry weight and are significantly higher in the southern basin of Lake Michigan (latitude <44°) than other parts of the three lakes. The highest concentration of alachlor was found in sediments of Saginaw Bay in Lake Huron. The inventory and net fluxes of these herbicides were found to decline exponentially from the south to the north. The concentration ratio of DEA to atrazine (DEA/ATZ) increased with latitude, suggesting degradation of atrazine to DEA during atmospheric transport. DEA/ATZ also increased with sediment depth in the sediment cores. Diffusion of deposited herbicides from the upper sediment into deeper sediments has occurred, on the basis of the observed patterns of concentrations in dated sediment cores. Concentrations of atrazine in pore water were estimated and were higher than those reported for the bulk waters, suggesting the occurrence of solid-phase deposition of atrazine through the water column and that contaminated sediments act as a source releasing atrazine to the overlying water.

  7. Occurrence of Atrazine and Related Compounds in Sediments of Upper Great Lakes.

    PubMed

    Guo, Jiehong; Li, Zhuona; Ranasinghe, Prabha; Bonina, Solidea; Hosseini, Soheil; Corcoran, Margaret B; Smalley, Colin; Kaliappan, Rajashankar; Wu, Yan; Chen, Da; Sandy, Andy L; Wang, Yawei; Rockne, Karl J; Sturchio, Neil C; Giesy, John P; Li, An

    2016-07-19

    Surface grab and core sediment samples were collected from Lakes Michigan, Superior, and Huron from 2010 to 2012, and concentrations of herbicides atrazine, simazine, and alachlor, as well as desethylatrazine (DEA), were determined. Concentrations of atrazine in surface grabs ranged from 0.01 to 1.7 ng/g dry weight and are significantly higher in the southern basin of Lake Michigan (latitude <44°) than other parts of the three lakes. The highest concentration of alachlor was found in sediments of Saginaw Bay in Lake Huron. The inventory and net fluxes of these herbicides were found to decline exponentially from the south to the north. The concentration ratio of DEA to atrazine (DEA/ATZ) increased with latitude, suggesting degradation of atrazine to DEA during atmospheric transport. DEA/ATZ also increased with sediment depth in the sediment cores. Diffusion of deposited herbicides from the upper sediment into deeper sediments has occurred, on the basis of the observed patterns of concentrations in dated sediment cores. Concentrations of atrazine in pore water were estimated and were higher than those reported for the bulk waters, suggesting the occurrence of solid-phase deposition of atrazine through the water column and that contaminated sediments act as a source releasing atrazine to the overlying water. PMID:27322944

  8. Development of controlled release formulations of alachlor in ethylcellulose.

    PubMed

    Fernandez-Urrusuno, R; Gines, J M; Morillo, E

    2000-01-01

    The herbicide alachlor (2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)-acetamide) is frequently implicated in groundwater contamination. Microencapsulated alachlor should have reduced potential for leaching in the soil while maintaining effective biological activity. Microspheres of alachlor were prepared using ethylcellulose, according to the solvent evaporation method. The influence of formulation variables affecting the release rate of pesticide, such as the molecular weight of ethylcellulose, the amount of emulsifying agent, the pesticide/polymer ratio and the particle size, were investigated. The results showed that microspheres retarded the release of alachlor in different degrees. Pesticide/polymer ratio and particle size were the more important factors determining the alachlor release. Ethylcellulose microspheres may prove useful for the prolonged release of alachlor.

  9. Mutagenicity study of butachlor and its metabolites using Salmonella typhimurium.

    PubMed

    Hsu, Kuei-Yao; Lin, Hwai-Jeng; Lin, Jen-Kun; Kuo, Wein-Shung; Ou, Yueh-Hsing

    2005-12-01

    Butachlor is the most commonly used herbicide in Taiwan and many other countries. It has been reported to be an indirect mutagen and carcinogen in various in vitro assay systems. Previous investigation has also demonstrated that butachlor stimulates cell proliferation, transforms normal embryonic cells, and induces stomach tumors in Spraque-Dawley rats. However, the mechanism of butachlor carcinogenicity is still not clear. In order to clarify the toxicologic and carcinogenic properties of butachlor, we proposed a metabolic pathway, and synthesized the authentic metabolites by chemical methods. In addition, we tested the mutagenicity of butachlor and these metabolites on Salmonella typhimurium. The results indicate that butachlor might manifest its carcinogenicity via the mutagenicity of its metabolic products. Although the molecular mechanism of butachlor-induced cellular toxicity is still not clear, it is likely that the cellular transformation ability of butachlor is partly associated with its mutagenicity.

  10. Butachlor-induced acute toxic hepatitis.

    PubMed

    Daryani, Nasser Ebrahimi; Hosseini, Parviz; Bashashati, Mohammad; Haidarali, Mona; Sayyah, Alireza

    2007-01-01

    Butachlor is a highly effective herbicidal substance widely used by farmers. We report a 60-year-old man with exfoliative dermatitis, jaundice, increase in liver enzymes and eosinophilia one day after accidental dermal exposure to butachlor toxin. The diagnostic workup showed no other cause and liver histology was consistent with substance-induced toxic hepatitis. Within two weeks of conservative therapy, his liver function tests returned to normal.

  11. Genotoxicity of the herbicide butachlor in cultured human lymphocytes.

    PubMed

    Sinha, S; Panneerselvam, N; Shanmugam, G

    1995-08-01

    Butachlor, a pre-emergence herbicide was investigated for its ability to induce sister chromatid exchanges (SCE) and chromosome aberrations (CA) in cultured human peripheral blood lymphocytes. Mitogen-stimulated lymphocytes were treated with three different concentrations (5, 10 and 20 micrograms/ml) of butachlor for 24, 48 and 72 h. Our results indicate a dose-dependent increase in the frequency of chromosomal aberrations at 24, 48 and 72 h of treatment with butachlor. No SCE was promoted by butachlor.

  12. Mineralization of the s-triazine ring of atrazine by stable bacterial mixed cultures.

    PubMed Central

    Mandelbaum, R T; Wackett, L P; Allan, D L

    1993-01-01

    Enrichment cultures containing atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) at a concentration of 100 ppm (0.46 mM) as a sole nitrogen source were obtained from soils exposed to repeated spills of atrazine, alachlor, and metolachlor. Bacterial growth occurred concomitantly with formation of metabolites from atrazine and subsequent biosynthesis of protein. When ring-labeled [14C]atrazine was used, 80% or more of the s-triazine ring carbon atoms were liberated as 14CO2. Hydroxyatrazine may be an intermediate in the atrazine mineralization pathway. More than 200 pure cultures isolated from the enrichment cultures failed to utilize atrazine as a nitrogen source. Mixing pure cultures restored atrazine-mineralizing activity. Repeated transfer of the mixed cultures led to increased rates of atrazine metabolism. The rate of atrazine degradation, even at the elevated concentrations used, far exceeded the rates previously reported in soils, waters, and mixed and pure cultures of bacteria. PMID:8328795

  13. Progression of alachlor-induced olfactory mucosal tumours

    PubMed Central

    Genter, Mary Beth; Burman, Dawn M; Bolon, Brad

    2002-01-01

    Alachlor is an herbicide used primarily in the production of corn (maize), peanuts, and soybeans and is associated with cancer of the nasal cavity, thyroid, and stomach in rats. Previous work from our laboratory demonstrated that the nasal cavity tumours originate from the olfactory mucosa, and that neoplasms were present following 6 months of exposure (126 mg/kg/day in the diet). The studies presented herein were conducted to determine more precisely the earliest time point at which alachlor-induced tumours were present, and to describe the histological changes that occur en route to tumour formation. We determined that dramatic histological changes, including respiratory metaplasia of the olfactory mucosa, were present following 3 months of exposure, and the earliest alachlor-induced olfactory mucosal tumours were detected following 5 months of treatment. Because alachlor is positive in short-term mutagenicity assays with olfactory mucosal activation, and because of the relatively short time-to-tumour formation observed with alachlor, we also conducted a ‘stop’ study in which rats were treated with alachlor for 1 month and then held without further treatment for an additional 5 months. This study demonstrated that abbreviated alachlor exposure did not result in subsequent tumour formation within the 6-month observation period. PMID:12657139

  14. Probability of detecting atrazine/desethyl-atrazine and elevated concentrations of nitrate in ground water in Colorado

    USGS Publications Warehouse

    Rupert, Michael G.

    2003-01-01

    Draft Federal regulations may require that each State develop a State Pesticide Management Plan for the herbicides atrazine, alachlor, metolachlor, and simazine. Maps were developed that the State of Colorado could use to predict the probability of detecting atrazine and desethyl-atrazine (a breakdown product of atrazine) in ground water in Colorado. These maps can be incorporated into the State Pesticide Management Plan and can help provide a sound hydrogeologic basis for atrazine management in Colorado. Maps showing the probability of detecting elevated nitrite plus nitrate as nitrogen (nitrate) concentrations in ground water in Colorado also were developed because nitrate is a contaminant of concern in many areas of Colorado. Maps showing the probability of detecting atrazine and(or) desethyl-atrazine (atrazine/DEA) at or greater than concentrations of 0.1 microgram per liter and nitrate concentrations in ground water greater than 5 milligrams per liter were developed as follows: (1) Ground-water quality data were overlaid with anthropogenic and hydrogeologic data using a geographic information system to produce a data set in which each well had corresponding data on atrazine use, fertilizer use, geology, hydrogeomorphic regions, land cover, precipitation, soils, and well construction. These data then were downloaded to a statistical software package for analysis by logistic regression. (2) Relations were observed between ground-water quality and the percentage of land-cover categories within circular regions (buffers) around wells. Several buffer sizes were evaluated; the buffer size that provided the strongest relation was selected for use in the logistic regression models. (3) Relations between concentrations of atrazine/DEA and nitrate in ground water and atrazine use, fertilizer use, geology, hydrogeomorphic regions, land cover, precipitation, soils, and well-construction data were evaluated, and several preliminary multivariate models with various

  15. Effects of butachlor on microbial enzyme activities in paddy soil.

    PubMed

    Min, Hang; Ye, Yang-Fang; Chen, Zhong-Yun; Wu, Wei-Xiang; Du, Yu-Feng

    2002-07-01

    This paper reports the influences of the herbicide butachlor (n-butoxymethl-chloro-2', 6'-diethylacetnilide) on microbial respiration, nitrogen fixation and nitrification, and on the activities of dehydrogenase and hydrogen peroxidase in paddy soil. The results showed that after application of butachlor with concentrations of 5.5 micrograms/g dried soil, 11.0 micrograms/g dried soil and 22.0 micrograms/g dried soil, the application of butachlor enhanced the activity of dehydrogenase at increasing concentrations. The soil dehydrogenase showed the highest activity on the 16th day after application of 22.0 micrograms/g dried soil of butachlor. The hydrogen peroxidase could be stimulated by butachlor. The soil respiration was depressed within a period from several days to more than 20 days, depending on concentrations of butachlor applied. Both the nitrogen fixation and nitrification were stimulated in the beginning but reduced greatly afterwards in paddy soil.

  16. Comparative proteome analysis of butachlor-degrading bacteria

    NASA Astrophysics Data System (ADS)

    Wang, Jinhua; Lu, Yitong; Chen, Yingying

    2008-01-01

    A Pseudomonas putida strain, named ER1, was isolated from an agricultural soil and found to actively degrade the herbicide butachlor. The enzyme extracted from ER1 could degrade butachlor. Furthermore, incubation of ER1 in a medium containing 50 mg/kg of butachlor after 3 days resulted in the high butachlor-degrading enzyme activity of ER1. Response of ER1 to butachlor might be related to changes in protein composition at both quantitative and qualitative levels. Total proteins were extracted from control strain (incubated in the medium without butachlor) and the treated strain (incubated in the medium with butachlor). The proteins were separated by two-dimensional gel electrophoresis. Of the total number of ER1 protein, 11 spots were significantly changed under butachlor stress. Analysis by matrix-assisted laser desorption/ionization mass spectrometry and tandem mass spectrometry coupled with database searching allowed the function of some proteins which were similar to the hydrolases activity or oxidoreductase activity.

  17. Probability of detecting atrazine/desethyl-atrazine and elevated concentrations of nitrate (NO2+NO3-N) in ground water in the Idaho part of the upper Snake River basin

    USGS Publications Warehouse

    Rupert, Michael G.

    1998-01-01

    Draft Federal regulations may require that each State develop a State Pesticide Management Plan for the herbicides atrazine, alachlor, cyanazine, metolachlor, and simazine. This study developed maps that the Idaho State Department of Agriculture might use to predict the probability of detecting atrazine and desethyl-atrazine (a breakdown product of atrazine) in ground water in the Idaho part of the upper Snake River Basin. These maps can be incorporated in the State Pesticide Management Plan and help provide a sound hydrogeologic basis for atrazine management in the study area. Maps showing the probability of detecting atrazine/desethyl-atrazine in ground water were developed as follows: (1) Ground-water monitoring data were overlaid with hydrogeologic and anthropogenic data using a geographic information system to produce a data set in which each well had corresponding data on atrazine use, depth to ground water, geology, land use, precipitation, soils, and well depth. These data then were downloaded to a statistical software package for analysis by logistic regression. (2) Individual (univariate) relations between atrazine/desethyl-atrazine in ground water and atrazine use, depth to ground water, geology, land use, precipitation, soils, and well depth data were evaluated to identify those independent variables significantly related to atrazine/ desethyl-atrazine detections. (3) Several preliminary multivariate models with various combinations of independent variables were constructed. (4) The multivariate models which best predicted the presence of atrazine/desethyl-atrazine in ground water were selected. (5) The multivariate models were entered into the geographic information system and the probability maps were constructed. Two models which best predicted the presence of atrazine/desethyl-atrazine in ground water were selected; one with and one without atrazine use. Correlations of the predicted probabilities of atrazine/desethyl-atrazine in ground water with

  18. Environmental fate of alachlor and metolachlor.

    PubMed

    Chesters, G; Simsiman, G V; Levy, J; Alhajjar, B J; Fathulla, R N; Harkin, J M

    1989-01-01

    Decision-makers, scientists, and the interested public should be informed what future research and education is needed if a strong pesticide regulatory program is imposed. Recommendations are intended to highlight research gaps. Some may be of general concern and apply to many pesticides. A situation that calls into question the value of many of our management decisions, is the lack of good field-scale experimentation and of logical mechanisms for translating and extrapolating laboratory data to field-scale dimensions. Many experiments were not designed to allow application of basic statistical criteria. High costs often preclude sufficient replication in field-scale experiments so that researchers must make the "no-win" choice between doing one investigation well or doing two or three poorly. The following observations about alachlor and metolachlor are provided: Pysicochemical properties are accurately determined. The herbicides' modes of action and plant selectivity have received a great deal of attention, but gaps remain in defining which of three modes of action are most important. Geographic distribution and extent of residue contamination of surface waters is documented, but groundwater contamination is poorly defined. Any groundwater monitoring protocol should limit the investigation based on sound scientific judgment since a nationwide monitoring network cannot be economically justified. Enough data are needed, however, to allow mathematical model development, verification and validation for a diversity of soil, geographic, climatic, and agricultural management conditions. In view of the importance of adsorption in determining the fate of pesticides, improved methods of determining adsorption coefficients (KD) are needed particularly for very low concentrations. The impact of soil aggregation on adsorption/desorption needs to be examined. The role of temperature and water content in adsorption/desorption processes needs clearer definition. Although

  19. The economics of atrazine.

    PubMed

    Ackerman, Frank

    2007-01-01

    It is often claimed that atrazine is of great economic benefit to corn growers, but support for this claim is limited. Some cost-benefit studies have assumed that atrazine boosts corn yields by 6%; an extensive review found a 3%-4% average yield increase; other research suggests only a 1% yield effect. Syngenta, the producer of atrazine, also makes mesotrione, an alternative herbicide that does about the same amount for corn yields as atrazine. Italy and Germany both banned atrazine in 1991, with no decrease in corn yields or harvested area. Even if atrazine leads to 6% more corn production, it is not certain that this would justify its continued use; a 1%, or perhaps zero, change does not warrant large-scale exposure of humans and the environment to this potentially hazardous chemical.

  20. Evaluation of mortality and cancer incidence among alachlor manufacturing workers.

    PubMed Central

    Acquavella, J F; Riordan, S G; Anne, M; Lynch, C F; Collins, J J; Ireland, B K; Heydens, W F

    1996-01-01

    Alachlor is the active ingredient in a family of preemergence herbicides. We assessed mortality rates from 1968 to 1993 and cancer incidence rates from 1969 to 1993 for manufacturing workers with potential alachlor exposure. For workers judged to have high alachlor exposure, mortality from all causes combined was lower than expected [23 observed, standardized mortality ratio (SMR) = 0.7, 95% CI, 0.4-1.0], cancer mortality was similar to expected (6 observed, SMR = 0.7, 95% CI, 0.3-1.6), and there were no cancer deaths among workers with 5 or more years high exposure and 15 or more years since first exposure (2.3 expected, SMR = 0, 95% CI, 0-1.6). Cancer incidence for workers with high exposure potential was similar to the state rate [18 observed, standardized incidence ratio (SIR) = 1.2, 95% CI, 0.7-2.0], especially for workers exposed for 5 or more years and with at least 15 years since first exposure (4 observed, SIR = 1.0, 95% CI, 0.3-2.7). The most common cancer for these latter workers was colorectal cancer (2 observed, SIR 3.9, 95% CI, 0.5-14.2 among workers). Despite the limitations of this study with respect to small size and exposure estimating, the findings are useful for evaluating potential alachlor-related health risks because past manufacturing exposures greatly exceeded those characteristic of agricultural operations. These findings suggest no appreciable effect of alachlor exposure on worker mortality or cancer incidence rates during the study period. PMID:8841758

  1. [The transferability of acetochlor and butachlor in soil].

    PubMed

    Zheng, H; Ye, C

    2001-09-01

    The transferability of acetochlor and butachlor in soil was studied by soil thin layer chromatography. Acetochlor and butachlor were dropped on the glass plate and spreaded soil on the glass plate was collected per 2 cm, then acetochlor and butachlor were analyzed quantitatively by HPlC. When river water was as the spread solution, Rf(relative flow) of acetochlor and butachlor in the Haidian loam were 0.116 and 0.031 respectively, Rf of acetochlor and butachlor in the Baiyangdian sandy loam were 0.147 and 0.032 respectively. When 30 mg.L-1 dodecylbenzene sulfonic acid sodium salt solution was as the spread solution, Rf of acetochlor and butachlor in the Haidian loam were 0.159 and 0.034 respectively. Acetochlor's transferability was weak and the gradation of its transferability was II grade, while butachlor's was more weak and the gradation was I grade. Anionic surfactant solution can promote pesticides to transfer. Cationic surfactant solution can impede pesticides to transfer.

  2. Biodegradation of acetanilide herbicides acetochlor and butachlor in soil.

    PubMed

    Ye, Chang-ming; Wang, Xing-jun; Zheng, He-hui

    2002-10-01

    The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matter addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soil-SDBS mixtures and soil-HA mixtures were 4.6 d, 6.1 d and 5.4 d and 5.3 d, 4.9 d and 5.3 d respectively. The biodegradation products were hydroxyacetochlor and 2-methyl-6-ethylaniline for acetochlor, and hydroxybutachlor and 2,6-diethylaniline for butachlor.

  3. An evaluation of the feasibility of using cytogenetic damage as a biomarker for alachlor exposure.

    PubMed

    Kligerman, A D; Erexson, G L

    1999-04-26

    Alachlor is a widely used herbicide for which there is significant human exposure, principally through groundwater contamination and inhalation. Because alachlor is purported to be carcinogenic and mutagenic, we initiated studies to determine if induced cytogenetic damage could be used as a biomarker for exposure to this herbicide. Both isolated and whole blood human lymphocytes were exposed to alachlor using several protocols. The lymphocytes were cultured for analysis of sister chromatid exchange (SCE), chromosome aberrations (CAs), micronuclei (MN) in cytochalasin B-induced binucleated cells, and proliferation kinetics using the replicative index (RI). In addition, CD rats were injected with either 10 or 50 mg kg-1 of alachlor, 2-chloro-N-(2,6-diethylphenyl) acetamide (CDEPA) or 2, 6-diethylanaline (DEA). After 24 h, the peripheral blood lymphocytes were removed and cultured for SCE and RI analysis. Alachlor did induce a concentration-related increase in SCE in vitro, but neither it nor its metabolites (CDEPA or DEA) induced a significant increase in SCEs or an alteration of RI in vivo. At the highest in vitro concentration tested, alachlor induced a statistically-significant increase in MN, but no concomitant increase in CAs was seen. From analyses of our data and the literature on alachlor clastogenicity and exposure levels, we concluded that cytogenetic damage may not be an adequately sensitive marker for evaluating human exposure to alachlor.

  4. KINETICS OF ALACHLOR TRANSFORMATION AND IDENTIFICATION OF METABOLITES UNDER ANAEROBIC CONDITIONS. (R825549C037)

    EPA Science Inventory

    Alachlor is one of the two most commonly used herbicides in the United States. In the environment, little mineralization of this compound has been found to occur, and metabolites of alachlor may be formed and could accumulate. The objectives of this study were to determine the...

  5. Rapid degradation of butachlor in wheat rhizosphere soil.

    PubMed

    Yu, Y L; Chen, Y X; Luo, Y M; Pan, X D; He, Y F; Wong, M H

    2003-02-01

    The degradative characteristics of butachlor in non-rhizosphere, wheat rhizosphere, and inoculated rhizosphere soils were measured. The rate constants for the degradation of butachlor in non-rhizosphere, rhizosphere, and inoculated rhizosphere soils were measured to be 0.0385, 0.0902, 0.1091 at 1 mg/kg, 0.0348, 0.0629, 0.2355 at 10 mg/kg, and 0.0299, 0.0386, 0.0642 at 100 mg/kg, respectively. The corresponding half-lives for butachlor in the soils were calculated to be 18.0, 7.7, 6.3 days at 1 mg/kg, 19.9, 11.0, 2.9 days at 10 mg/kg, and 23.2, 18.0, 10.8 days at 100 mg/kg, respectively. The experimental results show that the degradation of butachlor can be enhanced greatly in wheat rhizosphere, and especially in the rhizosphere inoculated with the bacterial community designated HD which is capable of degrading butachlor. It could be concluded that rhizosphere soil inoculated with microorganisms-degrading target herbicides is a useful pathway to achieve rapid degradation of the herbicides in soil.

  6. [Quantitative analysis of butachlor, oxadiazon and simetryn by gas chromatography].

    PubMed

    Liu, F; Mu, W; Wang, J

    1999-03-01

    The quantitative analysis of the ingredients in 26% B-O-S (butachlor, oxadiazon and simetryn) emulsion by gas chromatographic method was carried out with a 5% SE-30 on Chromosorb AW DMCS, 2 m x 3 mm i.d., glass column at column temperature of 210 degrees C and detector temperature of 230 degrees C. The internal standard is di-n-butyl sebacate. The retentions of simetryn, internal standard, butachlor and oxadiazon were 6.5, 8.3, 9.9 and 11.9 min respectively. This method has a recovery of 98.62%-100.77% and the coefficients of variation of this analysis of butachlor, oxadiazon and simetryn were 0.46%, 0.32% and 0.57% respectively. All coefficients of linear correlation were higher than 0.999.

  7. Embryonic exposure to butachlor in zebrafish (Danio rerio): endocrine disruption, developmental toxicity and immunotoxicity.

    PubMed

    Tu, Wenqing; Niu, Lili; Liu, Weiping; Xu, Chao

    2013-03-01

    Butachlor is a chloroacetanilide herbicide widely employed in weeding important crops. Recently, the study of the possible toxic effects of butachlor in non-target organisms has increased substantially. However, the endocrine disruption, developmental toxicity and immunotoxicity effects of butachlor in fish have not been fully investigated in previous studies. In the present study, zebrafish embryos were exposed to a range of butachlor concentrations from 4 to 20 μM to evaluate the embryonic toxicity of butachlor until 84 hours postfertilization (hpf). The results demonstrated that butachlor was highly toxic to zebrafish embryos, hindering the hatching process, resulting in a series of malformations and followed by mortality. The malformations observed included pericardial edema (PE) and yolk sac edema (YSE), which showed concentration-dependent responses. The analysis of endocrine gene transcription indicated that butachlor significantly induced the expression of the estrogen-responsive gene Vtg1 but had no effect on the expression of the ERα gene. The innate immune system appeared to be another possible target of butachlor. At 72 hpf, butachlor significantly up-regulated the innate immune system-related genes, including IL-1β, CC-chem, CXCL-C1c and IL-8. These data suggest that butachlor causes developmental toxicity, endocrine disruption and immune toxicity in the zebrafish embryo. Bidirectional interactions between the endocrine system and the immune system might be present, and further studies are needed to determine these possible pathways.

  8. Embryonic exposure to butachlor in zebrafish (Danio rerio): endocrine disruption, developmental toxicity and immunotoxicity.

    PubMed

    Tu, Wenqing; Niu, Lili; Liu, Weiping; Xu, Chao

    2013-03-01

    Butachlor is a chloroacetanilide herbicide widely employed in weeding important crops. Recently, the study of the possible toxic effects of butachlor in non-target organisms has increased substantially. However, the endocrine disruption, developmental toxicity and immunotoxicity effects of butachlor in fish have not been fully investigated in previous studies. In the present study, zebrafish embryos were exposed to a range of butachlor concentrations from 4 to 20 μM to evaluate the embryonic toxicity of butachlor until 84 hours postfertilization (hpf). The results demonstrated that butachlor was highly toxic to zebrafish embryos, hindering the hatching process, resulting in a series of malformations and followed by mortality. The malformations observed included pericardial edema (PE) and yolk sac edema (YSE), which showed concentration-dependent responses. The analysis of endocrine gene transcription indicated that butachlor significantly induced the expression of the estrogen-responsive gene Vtg1 but had no effect on the expression of the ERα gene. The innate immune system appeared to be another possible target of butachlor. At 72 hpf, butachlor significantly up-regulated the innate immune system-related genes, including IL-1β, CC-chem, CXCL-C1c and IL-8. These data suggest that butachlor causes developmental toxicity, endocrine disruption and immune toxicity in the zebrafish embryo. Bidirectional interactions between the endocrine system and the immune system might be present, and further studies are needed to determine these possible pathways. PMID:23294635

  9. Effects of butachlor on microbial populations and enzyme activities in paddy soil.

    PubMed

    Min, H; Ye, Y F; Chen, Z Y; Wu, W X; Yufeng, D

    2001-09-01

    This paper reports the influences of the herbicide butachlor (n-butoxymethlchloro -2', 6'-diethylacetnilide) on microbial populations, respiration, nitrogen fixation and nitrification, and on the activities of dehydrogenase and hydrogen peroxidase in paddy soil. The results showed that the number of actinomycetes declined significantly after the application of butachlor at different concentrations ranging from 5.5 microg g(-1) to 22.0 microg g(-1) dried soil, while that of bacteria and fungi increased. Fungi were easily affected by butachlor compared to the bacteria. The growth of fungi was retarded by butachlor at higher concentrations. Butachlor however, stimulated the growth of anaerobic hydrolytic fermentative bacteria, sulfate-reducing bacteria (SRB) and denitrifying bacteria. The increased concentration of butachlor applied resulted in the higher number of SRB. Butachlor inhibited the growth of hydrogen-producing acetogenic bacteria. The effect of butachlor varied on methane-producing bacteria (MPB) at different concentrations. Butachlor at the concentration of 1.0 microg g(-1) dried soil or less than this concentration accelerated the growth of MPB, while at 22.0 microg g(-1) dried soil showed an inhibition. Butachlor enhanced the activity of dehydrogenase at increasing concentrations. The soil dehydrogenase showed the highest activity on the 16th day after application of 22.0 microg g(-1) dried soil of butachlor. The hydrogen peroxidase could be stimulated by butachlor. The soil respiration was depressed during the period from several days to more than 20 days, depending on concentrations of butachlor applied. Both the nitrogen fixation and nitrification were stimulated in the beginning but reduced greatly afterwards in paddy soil.

  10. Metolachlor and alachlor breakdown product formation patterns in aquatic field mesocosms

    USGS Publications Warehouse

    Graham, W.H.; Graham, D.W.; DeNoyelles, F.; Smith, V.H.; Larive, C.K.; Thurman, E.M.

    1999-01-01

    The transformation of metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)- N-(2-methoxy-1-methyl)ethyl)acetamide] and alachlor [2-chloro-N-(2,6- diethylphenyl)-N-methoxymethyl)acetamide] in aquatic systems was investigated using outdoor tank mesocosms. Metolachlor and alachlor levels and their ethane sulfonic acid (ESA) and oxanillic acid breakdown products were monitored over time under five experimental treatments (each in quadruplicate). Background water conditions were identical in all treatments with each treatment differing based on the level and type(s) of herbicide present. Treatments included a noherbicide control, 10 ??g/L metolachlor, 25 ??g/L metolachlor, 25 ??g/L alachlor, and 25 ??g/L alachlor plus 25 ??g/L metolachlor in combination. The experiment was initiated by adding herbicide(s) to the units to the target concentrations; herbicide and breakdown product levels and other chemical parameters were then monitored for 85 days. In general, metolachlor half-lives were longer than alachlor half-lives under all treatments, although the differences were not statistically significant. Metolachlor half-lives (??95% confidence limits) ranged from 33.0 d (??14.1 d) to 46.2 d (??40.0 d), whereas alachlor half- lives ranged from 18.7 d (??3.5 d) to 21.0 d (??6.5 d) for different treatments. Formation patterns of ESA were similar in all treatments, whereas oxanillic acid formation differed for the two herbicides. Alachlor oxanillic acid was produced in larger quantities than metolachlor oxanillic acid and either ESA under equivalent conditions. Our results suggest that the transformation pathways for alachlor and metolachlor in aquatic systems are similar and resemble the acetochlor pathway in soils proposed by Feng (Pestic. Biochem. Physiol. 1991, 34, 136); however, the oxanillic acid branch of the pathway is favored for alachlor as compared with metolachlor.The transformation of metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N- (2-methoxy-1-methylethy

  11. Mechanism study of alachlor biodegradation by Paecilomyces marquandii with proteomic and metabolomic methods.

    PubMed

    Szewczyk, Rafał; Soboń, Adrian; Słaba, Mirosława; Długoński, Jerzy

    2015-06-30

    Alachlor is an herbicide that is widely used worldwide to protect plant crops against broadleaf weeds and annual grasses. However, due to its endocrine-disrupting activity, its application had been banned in the European Union. As described in our earlier work, Paecilomyces marquandii is a microscopic fungus capable of alachlor removal by N-acetyl oxidation. Our current work uses proteomics and metabolomics to gain a better understanding of alachlor biodegradation by the microscopic fungus P. marquandii. The data revealed that the addition of alachlor reduced the culture growth and glucose consumption rates. Moreover, the rates of glycolysis and the tricarboxylic acids (TCA) cycle increased during the initial stage of growth, and there was a shift toward the formation of supplementary materials (UDP-glucose/galactose) and reactive oxygen species (ROS) scavengers (ascorbate). Proteomic analysis revealed that the presence of xenobiotics resulted in a strong upregulation of enzymes related to energy, sugar metabolism and ROS production. However, the unique overexpression of cyanide hydratase in alachlor-containing cultures may implicate this enzyme as the key protein involved in the alachlor biodegradation pathway. The characterization of P. marquandii-mediated alachlor removal in terms of cell structure and function provides a deeper insight into the strategies of microorganisms toward xenobiotic biodegradation. PMID:25765177

  12. Mechanism study of alachlor biodegradation by Paecilomyces marquandii with proteomic and metabolomic methods.

    PubMed

    Szewczyk, Rafał; Soboń, Adrian; Słaba, Mirosława; Długoński, Jerzy

    2015-06-30

    Alachlor is an herbicide that is widely used worldwide to protect plant crops against broadleaf weeds and annual grasses. However, due to its endocrine-disrupting activity, its application had been banned in the European Union. As described in our earlier work, Paecilomyces marquandii is a microscopic fungus capable of alachlor removal by N-acetyl oxidation. Our current work uses proteomics and metabolomics to gain a better understanding of alachlor biodegradation by the microscopic fungus P. marquandii. The data revealed that the addition of alachlor reduced the culture growth and glucose consumption rates. Moreover, the rates of glycolysis and the tricarboxylic acids (TCA) cycle increased during the initial stage of growth, and there was a shift toward the formation of supplementary materials (UDP-glucose/galactose) and reactive oxygen species (ROS) scavengers (ascorbate). Proteomic analysis revealed that the presence of xenobiotics resulted in a strong upregulation of enzymes related to energy, sugar metabolism and ROS production. However, the unique overexpression of cyanide hydratase in alachlor-containing cultures may implicate this enzyme as the key protein involved in the alachlor biodegradation pathway. The characterization of P. marquandii-mediated alachlor removal in terms of cell structure and function provides a deeper insight into the strategies of microorganisms toward xenobiotic biodegradation.

  13. The influence of alachlor, trifluralin, and diazinon on the development of endogenous mycorrhizae in soybeans.

    PubMed

    Burpee, L L; Cole, H

    1978-02-01

    Preplant incorporated treatments of 2 and 4 kg/ha of trifluralin and diazinon had no significant effect on growth, P accumulation or root colonization by mycorrhizal fungi in soybeans planted in an Andover clay loam. At 4 kg/ha, alachlor and trifluralin inhibited root development of 25 day-old plants. The 4 kg/ha alachlor treatment reduced shoot weight of 25 day old plants significantly and suppressed mycorrhizal development of 25 to 60 day old plants. At currently used commercial rates neither alachlor, trifluralin, nor diazinon affected mycorrhizal development under the conditions of the experiment.

  14. Compilation of atrazine and selected herbicide data from previous surface-water-quality investigations within the Big Blue River basin, Nebraska, 1983-92

    USGS Publications Warehouse

    Frankforter, J.D.

    1994-01-01

    Atrazine has been detected in the surface water of the Big Blue River Basin during every month of the year. Recent data (1983-92) documenting the occurrence of atrazine and related herbicides in the surface water of the basin are compiled in this report. In samples analyzed during these studies, atrazine was the herbicide detected most frequently within the basin. Of the 385 samples analyzed, 369 contained atrazine in detectable concentrations with detection levels varying from 0 to 0.1 micrograms per liter. The concentrations of atrazine within the samples varied from 0.5 to 166 micrograms per liter, with a median concentration of 2.7 micrograms per liter. Other herbicides frequently detected in the Big Blue River Basin were alachlor, cyanazine, metolachlor, and simazine, and two metabolites of atrazine, desethylatrazine and deisopropylatrazine. In the 226 samples which alachlor was detected, the concentrations of the herbicide ranged from 0.05 to 56 micrograms per liter, and the median concen- tration was 1.1 micrograms per liter. Cyanazine was detected in 210 of 365 samples collected with con- centrations that ranged from 0.05 to 8.6 micrograms per liter with a median concentration of 0.4 microgram per liter. The maximum concentrations of metolachlor and simazine were 26 and 35 micrograms per liter, respectively. The median concentrations of these herbicides were 1.0 and 0.1 micrograms per liter, respectively. The maximum concentration of desethylatrazine, was 3.7 micrograms per liter, with a median concentration of 1.0 microgram per liter. Deisopropylatrazine, was detected in 152 samples with maximum and median concentrations of 2.6 and 0.6 micrograms per liter, respectively.

  15. Butachlor, a suspected carcinogen, alters growth and transformation characteristics of mouse liver cells.

    PubMed

    Ou, Y H; Chung, P C; Chang, Y C; Ngo, F Q; Hsu, K Y; Chen, F D

    2000-12-01

    Butachlor is a widely used herbicide in Asia and South America. Previous investigations have indicated that it is a suspected carcinogen. To understand more about the biological effects of butachlor on cultured cells and the mechanism(s) of its carcinogenicity, we studied the alteration of the growth characteristics that was induced by butachlor in normal mouse liver cells (BNL CL2). This study demonstrates that butachlor decreases the population-doubling time of BNL CL2 cells, suggesting that it stimulates cell proliferation. To support this finding, a thymidine incorporation assay was conducted and a similar result that butachlor stimulates cell proliferation was elucidated. In addition, we show that butachlor increases the saturation density of the BNL CL2 cells. When combined with the tumor initiator N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), butachlor transforms cells efficiently, as demonstrated by loss of contact inhibition. These findings indicate that butachlor alters the growth characteristics of BNL CL2 cells and suggest that butachlor may induce malignant transformation through stimulation of cell proliferation, alteration of cell cycle regulation, and suppression of cell density-dependent inhibition of proliferation.

  16. [Effect of butachlor on CH4 emission and anaerobes in paddy soil].

    PubMed

    Zhao, Y; Mei, Q; Chen, M; Min, H

    1997-12-01

    Effects of butachlor on CH4 emission and the count of anaerobes in paddy soil or in the media were studied. The results obtained showed that CH4 emission and growth of methanogens would be greatly affected at field rates of butachlor within 2 weeks, but this adverse effects would disappear as time went on. CH4 emission and methanogenic activities would be retarded by butachlor in media for longer time. The amount of butachlor available to act upon anaerobes depended on application rate and method of application.

  17. ANALYTICAL METHOD DEVELOPMENT FOR ALACHLOR ESA AND OTHER ACETANILIDE HERBICIDE DEGRADATION PRODUCTS

    EPA Science Inventory

    In 1998, USEPA published a Drinking Water Contaminant Candidate List (CCL) of 50 chemicals and 10 microorganisms. "Alachlor ESA and other acetanilide herbicide degradation products" is listed on the the 1998 CCL. Acetanilide degradation products are generally more water soluble...

  18. Formation and transport of the sulfonic acid metabolites of alachlor and metolachlor in soil

    USGS Publications Warehouse

    Aga, D.S.; Thurman, E.M.

    2001-01-01

    Alachlor and metolachlor are dechlorinated and transformed into their corresponding ethane sulfonic acid (ESA) metabolites in soil. In a field-disappearance study, it was shown that alachlor ESA was formed at a faster rate and at concentrations 2-4 times higher than metolachlor ESA, conforming with the observed longer disappearance half-life of metolachlor (15.5 d) in the field as compared to alachlor (8 d). Runoff data also showed higher concentrations of alachlor ESA as compared to metolachlor ESA, even though they were applied at the same levels. Data from soil cores showed transport of the ESA compounds in soil to as far down as 75-90 cm below the surface, at concentrations ranging from less than 0.5 ??g/L to about 50 ??g/L. In contrast, no parent herbicide was detected at these depths. This observation correlates with the higher log KOC values for alachlor (3.33) and metolachlor (3.01) relative to their corresponding ESA metabolites, alachlor ESA (2.26), and metolachlor ESA (2.29).

  19. Degradation of alachlor using an enhanced sono-Fenton process with efficient Fenton's reagent dosages.

    PubMed

    Wang, Chikang; Liu, Zonghan

    2015-01-01

    In this study, an enhanced sono-Fenton process for the degradation of alachlor is presented. At high ultrasonic power, low pH, and in the presence of adequate Fenton's reagent dosages, alachlor degradation can reach nearly 100%. The toxicity of treated alachlor wastewater, which was measured by changes in cell viability, slightly decreased after the Fenton or ultrasound/H2O2 process and significantly decreased after the enhanced sono-Fenton process. A satisfactory relationship was observed between the total organic carbon removal and cell viability increment, indicating that alachlor mineralization is a key step in reducing the toxicity of the solution. The formation of alachlor degradation byproducts was observed during the oxidation process, in which the first step was the substitution of a chloride by a hydroxyl group. In conclusion, the enhanced sono-Fenton process was effective in the degradation and detoxification of alachlor within a short reaction time. Thus, the treated wastewater can then be passed through a biological treatment unit for further treatment.

  20. Ethylcellulose formulations for controlled release of the herbicide alachlor in a sandy soil.

    PubMed

    Sopeña, Fátima; Cabrera, Alegría; Maqueda, Celia; Morillo, Esmeralda

    2007-10-01

    The development of controlled-release formulations of alachlor to diminish its leaching in sandy soils, avoiding groundwater contamination and maintaining its efficacy, was studied. For this purpose, ethylcellulose (EC) microencapsulated formulations (MEFs) of alachlor were prepared under different conditions and applied to soil columns to study their mobility. The results show that in all cases the release into water of alachlor from MEFs was retarded when compared with commercial formulation. Total leaching losses in soil columns were reduced to 59% from 98%. The mobility of alachlor from EC microspheres into soil columns has been greatly diminished in comparison with its current commercial formulation (CF), above all with increasing EC/herbicide ratios. Distribution of alachlor applied as MEFs at different depths in the soil was higher in the soil surface (66.3-81.3% of herbicide applied at the first 12 cm). In contrast, the residues from CF along the complete soil column were only 20.4%. From the results of bioassays, MEFs showed a higher efficacy than CF at 30 days after the treatment. The use of ME formulations could provide an advantage in minimizing the risk of groundwater contamination by alachlor and reducing the application rates, as a result of maintaining the desired concentration of the herbicide in the top soil layer, obtaining longer periods of weed control.

  1. Would banning atrazine benefit farmers?

    PubMed Central

    Ackerman, Frank; Whited, Melissa; Knight, Patrick

    2014-01-01

    Atrazine, an herbicide used on most of the US corn (maize) crop, is the subject of ongoing controversy, with increasing documentation of its potentially harmful health and environmental impacts. Supporters of atrazine often claim that it is of great value to farmers; most recently, Syngenta, the producer of atrazine, sponsored an “Atrazine Benefits Team” (ABT) of researchers who released a set of five papers in 2011, reporting huge economic benefits from atrazine use in US agriculture. A critical review of the ABT papers shows that they have underestimated the growing problem of atrazine-resistant weeds, offered only a partial review of the effectiveness of alternative herbicides, and ignored the promising option of non-chemical weed management techniques. In addition, the most complete economic analysis in the ABT papers implies that withdrawal of atrazine would lead to a decrease in corn yields of 4.4% and an increase in corn prices of 8.0%. The result would be an increase in corn growers’ revenues, equal to US$1.7 billion annually under ABT assumptions. Price impacts on consumers would be minimal: at current levels of ethanol production and use, gasoline prices would rise by no more than US$0.03 per gallon; beef prices would rise by an estimated US$0.01 for a 4-ounce hamburger and US$0.05 for an 8-ounce steak. Thus withdrawal of atrazine would boost farm revenues, while only changing consumer prices by pennies. PMID:24804340

  2. Would banning atrazine benefit farmers?

    PubMed

    Ackerman, Frank; Whited, Melissa; Knight, Patrick

    2014-01-01

    Atrazine, an herbicide used on most of the US corn (maize) crop, is the subject of ongoing controversy, with increasing documentation of its potentially harmful health and environmental impacts. Supporters of atrazine often claim that it is of great value to farmers; most recently, Syngenta, the producer of atrazine, sponsored an "Atrazine Benefits Team" (ABT) of researchers who released a set of five papers in 2011, reporting huge economic benefits from atrazine use in US agriculture. A critical review of the ABT papers shows that they have underestimated the growing problem of atrazine-resistant weeds, offered only a partial review of the effectiveness of alternative herbicides, and ignored the promising option of nonchemical weed management techniques. In addition, the most complete economic analysis in the ABT papers implies that withdrawal of atrazine would lead to a decrease in corn yields of 4.4% and an increase in corn prices of 8.0%. The result would be an increase in corn growers' revenues, equal to US$1.7 billion annually under ABT assumptions. Price impacts on consumers would be minimal: at current levels of ethanol production and use, gasoline prices would rise by no more than US$0.03 per gallon; beef prices would rise by an estimated US$0.01 for a 4-ounce hamburger and US$0.05 for an 8-ounce steak. Thus withdrawal of atrazine would boost farm revenues, while only changing consumer prices by pennies.

  3. Effects of butachlor on reproduction and hormone levels in adult zebrafish (Danio rerio).

    PubMed

    Chang, Juhua; Liu, Shaoying; Zhou, Shengli; Wang, Minghua; Zhu, Guonian

    2013-01-01

    Butachlor, a chloracetamide herbicide, is widely used in China. In the present study, paired adult male and female zebrafish (Danio rerio) were exposed to various concentrations of butachlor (0, 25, 50 and 100 μg/L) for 30 days, and the effects on reproduction and endocrine disruption were evaluated using fecundity, condition factor (CF), gonadosomatic index (GSI), liver somatic index (LSI), plasma vitellogenin (VTG), sex steroids and thyroid hormone levels as endpoints. Our results showed that the mean fecundity rates were significantly decreased at 50 and 100 μg/L butachlor during the 30-day exposure period. At the end of the exposure period, no significant changes were observed in CF and LSI in both females and males, while GSI was significantly reduced in males at 50 and 100 μg/L butachlor. At 100 μg/L butachlor, plasma testosterone (T) and 17β-estradiol (E2) levels were significantly decreased in females, while plasma VTG level was significantly increased in males. Plasma thyroxine (T4) and triiodothyronine (T3) levels were significantly increased at 50 and 100 μg/L butachlor in males, and at 100 μg/L in females. This work demonstrated that butachlor adversely affected the normal reproductive success of zebrafish, and disrupted the thyroid and sex steroid endocrine systems, which provides the basis for the estimated ecological risk during butachlor exposure.

  4. Bioavailability of butachlor and myclobutanil residues in soil to earthworms.

    PubMed

    Yu, Y L; Wu, X M; Li, S N; Fang, H; Tan, Y J; Yu, J Q

    2005-05-01

    To establish chemical extraction procedures for predicting bioavailability of butachlor and myclobutanil in soil, several solvent systems, including methanol, methanol-water (9:1), methanol-water (1:1), acetone-water (5:3), petroleum ether and water, were assessed for their feasibility in determining extractability of the target compounds from soil samples. Experimental data showed that the extractability of butachlor and myclobutanil by the solvents was well linearly correlated with their bioavailability to Eisenia foetida and Allolobophora caliginosa, indicating that these extraction procedures may be efficient for predicting bioavailability of the two pesticides. The concentrations of the pesticides accumulated in E. foetida and A. caliginosa varied with species, suggesting that the availability of the soil-sequestered pesticide is a species-dependent process.

  5. Rapid polyelectrolyte-based membrane immunoassay for the herbicide butachlor.

    PubMed

    Dzantiev, B B; Byzova, N A; Zherdev, A V; Hennion, M C

    2005-01-01

    Oppositely charged water-soluble polyelectrolytes were used in the developed membrane immunoenzyme assay for the herbicide butachlor. High-affinity and rapid binding between polyanion polymethacrylate and polycation poly(N-ethyl-4-vinylpyridinium) was applied to separate reacted and free immunoreactants. Competitive immunoassay format with peroxidase-labeled antigen was realized. The insoluble colored product of the peroxidase reaction was formed by bound labeled immune complexes and was reflectometrically detected. The assay combines short duration (15 min), high sensitivity (0.03 g/mL) and availability for out-of-laboratory testing. Different image processing algorithms were used to determine the herbicide content. Low variation coefficients of the measurements in the proposed quantitative assay, namely 4.8-9.0% for the range of antigen concentrations from 0.1 to 3.0 ng/mL, are evidence of the assay effectiveness. Possibility to control the butachlor content in mineral, artesian, and drinking water was demonstrated.

  6. Butachlor is cytotoxic and clastogenic and induces apoptosis in mammalian cells.

    PubMed

    Panneerselvam, N; Sinha, S; Shanmugam, G

    1999-09-01

    The ability of butachlor to induce cytotoxicity, clastogenicity and DNA damage was assessed using Chinese hamster ovary cells (CHO), Swiss mouse embryo fibroblasts (MEF) and human peripheral blood lymphocytes. A dose and time dependent loss of viability was evident upon treatment of CHO cells with butachlor. Cell killing to an extent of 50% was observed when cells were treated with 16.2 micrograms/ml of butachlor for 24 hr or with 11.5 micrograms/ml for 48 hr. The herbicide induced micronuclei significantly in cultured lymphocytes at 24 and 48 hr of treatment suggesting that it is clastogenic. To understand the mechanism of cell death caused by butachlor, its effect on DNA strand breaks was studied in MEF. A concomitant decrease in cell viability was observed with increase in DNA strand breaks. Agarose gel electrophoresis of DNA from herbicide treated CHO cells and cytochemical staining indicate the induction of apoptosis by butachlor.

  7. Inclusion complex of butachlor with beta-cyclodextrin: characterization, solubility, and speciation-dependent adsorption.

    PubMed

    Bian, Haitao; Chen, Jingwen; Cai, Xiyun; Liu, Ping; Liu, Huihui; Qiao, Xianliang; Huang, Liping

    2009-08-26

    Due to soil adsorption, higher amounts of the herbicide butachlor are necessary to achieve its herbicidal activity, hence increasing its environmental risks. In this study, the effects of beta-cyclodextrin (beta-CD) on solubility and soil adsorption of butachlor were investigated. Formation of a 1:1 stoichiometric inclusion complex between them with an apparent stability constant of 443 L mol(-1) was confirmed in the solution. Fourier transform infrared spectroscopy showed that the (N-CO) amide bond and alkyl ether moiety of butachlor molecule could enter into the cavity of beta-CD, but the double-substituted aromatic ring was excluded because it was larger size than the cavity. Significant enhancing dissolution of butachlor in the inclusion complex occurred in comparison to the free herbicide. The adsorption of butachlor on soil was reduced with an increase of beta-CD concentration because of the formation of the inclusion complex with low adsorption potency. Although the sorption distribution coefficient of complexed butachlor (i.e., butachlor/beta-cyclodextrin inclusion complex) (K(d,c) = 6.14) was about 14% of that of the free herbicide (K(d,f) = 44.54), the proportion of the adsorbed amount of complexed butachlor to the total adsorbed amount rose with the increase of beta-CD concentration. Thus, the adsorption of inclusion complex cannot be neglected in the presence of high concentrations cyclodextrins, although its water solubility was much higher than that of the free herbicide. These results indicate that beta-CD may be used as a formation additive to improve the solubility of butachlor, reduce its adsorption on soil, and increase the availability of butachlor for weeds.

  8. Henry's law constants measurements of alachlor and dichlorvos between 283 and 298 K

    NASA Astrophysics Data System (ADS)

    Gautier, Céline; Le Calvé, Stéphane; Mirabel, Philippe

    In this work, a dynamic system based on the water/air equilibrium at the interface within the length of a microporous tube was used to determine experimentally the Henry's law constants (HLC) of two pesticides: alachlor and dichlorvos. The measurements were conducted over the range 283-298 K. At 298 K, HLC were found to be equal to HLC=(14±2)×10 3 and HLC=(4.0±0.6)×10 3 (in units of M atm -1) for alachlor and dichlorvos, respectively. The obtained data were use to derive the following Arrhenius expressions: HLC=(8.0±3.4)×10 -10 exp((9200±1600)/ T) for alachlor and HLC=(2.8±0.4)×10 -13 exp((11 100±1500)/ T) for dichlorvos. At a cumulus temperature of 283 K, the fraction of alachlor and dichlorvos in the atmospheric aqueous phase is about 45% and 22%, respectively. Assuming that annual rainfall rate is 1 m/year, the wet deposition lifetimes were then estimated to be of the order of 2.8 days for alachlor and 5.6 days for dichlorvos. These latter are used to compare the relative importance of wet removal towards the lifetime in the gas phase.

  9. Removal of alachlor from water by catalyzed ozonation on Cu/Al2O3 honeycomb

    PubMed Central

    2013-01-01

    Background The herbicide alachlor (2-chloro-2′6′-diethyl-N-methoxymethylacetanilide) has been known as a probable human carcinogen, and the MCL (minimum contamination level) for drinking water has been set at 2 μg L-1. Therefore, the advanced methods for effectively removing it from water are a matter of interest. Catalyzed ozonation is a promising method for refractory organics degradation. Cu/Al2O3 catalyzed ozonation for degrading an endocrine disruptor (alachlor) in water was investigated. Results Experimental results showed that the ozonation of alachlor can be effectively catalyzed and enhanced by Cu/Al2O3-honeycomb. The main intermediate products formed (aliphatic carboxylic acids) were mineralized to a large extent in the catalytic process. Conclusions This study has shown that Cu/Al2O3-honeycomb is a feasible and efficient catalyst in the ozonation of alachlor in water. Less intermediate oxidation product was produced in the catalytic process than in the uncatalytic one. Furthermore, the mineralization of alachlor could be enhanced by increasing the pH of the reaction solution. PMID:23977841

  10. Biodegradation and mineralization of metolachlor and alachlor by Candida xestobii.

    PubMed

    Munoz, Ana; Koskinen, William C; Cox, Lucía; Sadowsky, Michael J

    2011-01-26

    Metolachlor (2-chloro-6'-ethyl-N-(2-methoxy-1-methylethyl)aceto-o-toluidide) is a pre-emergent chloroacetanilide herbicide used to control broadleaf and annual grassy weeds in a variety of crops. The S enantiomer, S-metolachlor, is the most effective form for weed control. Although the degradation of metolachlor in soils is thought to occur primarily by microbial activity, little is known about the microorganisms that carry out this process and the mechanisms by which this occurs. This study examined a silty-clay soil (a Luvisol) from Spain, with 10 and 2 year histories of metolachlor and S-metolachlor applications, respectively, for microorganisms that had the ability to degrade this herbicide. Tis paper reports the isolation and characterization of pure cultures of Candida xestobii and Bacillus simplex that have the ability to use metolachlor as a sole source of carbon for growth. Species assignment was confirmed by morphological and biochemical criteria and by sequence analysis of 18S and 16S rRNA, respectively. High-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) analyses indicated that C. xestobii degraded 60% of the added metolachlor after 4 days of growth and converted up to 25% of the compound into CO(2) after 10 days. In contrast, B. simplex biodegraded 30% of metolachlor following 5 days of growth in minimal medium. In contrast, moreover, the yeast degraded other acetanilide compounds and 80% of acetochlor (2-chloro-N-ethoxymethyl-6'-ethylaceto-o-toluidide) and alachlor (2-chloro-2',6'-diethyl-N-methoxymethylacetanilide) were degraded after 15 and 41 h of growth, respectively. The results of these studies indicate that microorganisms comprising two main branches of the tree of life have acquired the ability to degrade the same novel chlorinated herbicide that has been recently added to the biosphere. PMID:21190381

  11. Alachlor transformation patterns in aquatic field mesocosms under variable oxygen and nutrient conditions

    USGS Publications Warehouse

    Graham, D.W.; Miley, M.K.; Denoyelles, F.; Smith, V.H.; Thurman, E.M.; Carter, R.

    2000-01-01

    Alachlor is one of the most commonly used herbicides in both Europe and North America. Because of its toxic properties, its fate and attenuation in natural waters is practically important. This paper assesses factors that affect alachlor decay rate in aquatic systems using field-scale experimental units. In particular, we used field mesocosms (11.3 m3 outdoor fiberglass tanks) to examine the affect of oxygen level and other factors on decay rate in water columns. This is one of the first studies ever performed where diverse water column conditions have been successfully simulated using common mesocosm-scale facilities. Four treatments were assessed, including aerobic systems (aerobic); low nutrient, oxygen-stratified systems (stratified-LN); moderate nutrient, oxygen-stratified systems (stratified-HN); and anaerobic systems (anaerobic). The lowest half-lives were observed in the anaerobic units (9.7 days) followed by the aerobic (21 days), stratified-HN (22 days), and stratified-LN (46 days) units. Our results indicate that alachlor is transformed most rapidly under anaerobic conditions, although the ambient phosphorus level also appears to influence decay rate. In this study, two common alachlor breakdown products, ethane sulfonic acid (ESA) and oxanilic acid, were also monitored. Oxanilic acid was produced in greater quantities than ESA under all treatments with the highest levels being produced in the stratified-HN units. In general, our results suggest that previous laboratory data, which indicated that high rates of alachlor decay can occur under oxygen-free methanogenic conditions, is translatable to field-scale applications. Copyright (C) 2000 Elsevier Science Ltd.Alachlor is one of the most commonly used herbicides in both Europe and North America. Because of its toxic properties, its fate and attenuation in natural waters is practically important. This paper assesses factors that affect alachlor decay rate in aquatic systems using field-scale experimental

  12. Comprehensive spectroscopic probing the interaction and conformation impairment of bovine serum albumin (BSA) by herbicide butachlor.

    PubMed

    Liu, Xiaoyi; Ling, Zhaoxing; Zhou, Xing; Ahmad, Farooq; Zhou, Ying

    2016-09-01

    Butachlor is an effective herbicide to deal with undesired weeds selectively and is used at high levels in Asian countries. However, its interaction and impairment effect on BSA was still not clear. In this study, we investigated the interaction between butachlor and bovine serum albumin (BSA) by multi-spectroscopic methods including UV absorption, circular dichroism (CD) spectra, Fourier transform infrared (FTIR) spectra and fluorescence spectra under physiological conditions (pH=7.4). The results revealed that there was a static quenching of BSA induced by butachlor stemmed from the formation of complex. Based on thermodynamic data, the interaction of butachlor with BSA was due to happen, and van der Waals force as well as hydrogen bond were the major forces contributed to the interaction. The binding constant Kb and number of binding site of butachlor with BSA were 5.158×10(5) and 1.372 at 303K, respectively. The distance r between donor (BSA) and acceptor (butachlor) was 0.113nm, obtained according to the Förster theory. The results revealed that butachlor induced conformational changes in BSA but the secondary structure of BSA was still retained. In addition, the microenvironment around chromophore residues of BSA, for example, tryptophan, changed as well, resulting from the formation of more hydrogen bonds. PMID:27419617

  13. Comprehensive spectroscopic probing the interaction and conformation impairment of bovine serum albumin (BSA) by herbicide butachlor.

    PubMed

    Liu, Xiaoyi; Ling, Zhaoxing; Zhou, Xing; Ahmad, Farooq; Zhou, Ying

    2016-09-01

    Butachlor is an effective herbicide to deal with undesired weeds selectively and is used at high levels in Asian countries. However, its interaction and impairment effect on BSA was still not clear. In this study, we investigated the interaction between butachlor and bovine serum albumin (BSA) by multi-spectroscopic methods including UV absorption, circular dichroism (CD) spectra, Fourier transform infrared (FTIR) spectra and fluorescence spectra under physiological conditions (pH=7.4). The results revealed that there was a static quenching of BSA induced by butachlor stemmed from the formation of complex. Based on thermodynamic data, the interaction of butachlor with BSA was due to happen, and van der Waals force as well as hydrogen bond were the major forces contributed to the interaction. The binding constant Kb and number of binding site of butachlor with BSA were 5.158×10(5) and 1.372 at 303K, respectively. The distance r between donor (BSA) and acceptor (butachlor) was 0.113nm, obtained according to the Förster theory. The results revealed that butachlor induced conformational changes in BSA but the secondary structure of BSA was still retained. In addition, the microenvironment around chromophore residues of BSA, for example, tryptophan, changed as well, resulting from the formation of more hydrogen bonds.

  14. The toxic mechanism of high lethality of herbicide butachlor in marine flatfish flounder, Paralichthys olivaceus

    NASA Astrophysics Data System (ADS)

    Guo, Huarong; Yin, Licheng; Zhang, Shicui; Feng, Wenrong

    2010-09-01

    The toxic mechanism of herbicide butachlor to induce extremely high lethality in marine flatfish flounder, Paralichthys Olivaceus, was analyzed by histopathological examination, antioxidant enzymes activities and ATP content assay. Histopathological examination of gill, liver and kidney of exposed fishes showed that gill was a target organ of butachlor. The butachlor seriously impaired the respiration of gills by a series of lesions such as edema, lifting and detachment of lamellar epithelium, breakdown of pillar cells, and blood congestion. The dysfunction of gill respiration caused suffocation to the exposed flounder with extremely high acute lethality. Antioxidant enzyme activity assay of the in vitro cultured flounder gill (FG) cells exposed to butachlor indicated that butachlor markedly inhibited the antioxidant enzyme activities of Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). Furthermore, along with the decline of antioxidant enzyme activities, ATP content in the exposed FG cells decreased, too. This infers that the oxidative stress induced by butachlor can inhibit the production of cellular ATP. Similar decrease of ATP content was also observed in the exposed flounder gill tissues. Taken together, as in FG cells, butachlor possibly induced a short supply of ATP in pillar cells by inhibiting the antioxidant enzyme activities and then affecting the contractibility of the pillar cells, which in turn resulted in the blood congestion and suffocation of exposed flounder.

  15. Exposure to butachlor causes thyroid endocrine disruption and promotion of metamorphosis in Xenopus laevis.

    PubMed

    Li, Shuying; Li, Meng; Wang, Qiangwei; Gui, Wenjun; Zhu, Guonian

    2016-06-01

    Butachlor is extensively applied in rice paddy ecosystem in china, and has been widespread contaminant in the aquatic environment. Here, Xenopus laevis was used for the evaluation of teratogenesis developmental toxicity, and disruption of thyroid system when exposure to different concentrations of butachlor by window phase exposure. Acute toxicity investigation shown that 96 h-LC50 value of butachlor was 1.424 mg L(-1) and 0.962 mg L(-1) for tadpoles (starting from stages 46/47) and embryos (starting from stages 8/9), respectively. Exposure to butachlor caused malformation, including abnormal eye, pericardial edema, enlarged proctodaeum and bent tail. Window phase exposure test indicated that butachlor significantly promote the contents of whole-body thyroid hormones (THs, T3 and T4) at higher levels, indicating thyroid endocrine disruption. At 7 days, exposure to butachlor up-regulated the mRNA expression of genes involved in THs synthesis and metabolism (tshα, tg, tpo and dio1) and THs receptors (trα and trβ). At 14 days, up-regulation of the mRNA expression of genes related to THs synthesis and metabolism (tshα, tshβ, tg, tpo, dio1, dio2 and ttr) and THs receptors (trβ) were also observed after the exposure to butachlor. At 21 days, butachlor up-regulated the mRNA expression of tshα, tg, tpo genes and down-regulated the mRNA expression of tshβ, tg, dio1, ttr and trα genes. These results showed that butachlor could change the mRNA expression of genes involved in the HPT axis and increase whole-body thyroid hormones levels of X. laevis tadpoles in a dose- and time-dependent manner, causing thyroid endocrine disruption and developmental toxicity.

  16. Whole genome sequence analysis of an Alachlor and Endosulfan degrading Pseudomonas strain W15Feb9B isolated from Ochlockonee River, Florida.

    PubMed

    Chauhan, Ashvini; Pathak, Ashish; Ewida, Ayman Y I; Griffiths, Zabrenna; Stothard, Paul

    2016-06-01

    We recently isolated a Pseudomonas sp. strain W15Feb9B from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides - Alachlor [(2-chloro-2',6'-diethylphenyl-N (methoxymethyl)acetanilide)] and Endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(e)di-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain W15Feb9B, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of strain 2385 has been deposited in GenBank under accession number JTKF00000000; BioSample number SAMN03151543. The sequences obtained from strain 2385 assembled into 192 contigs with a genome size of 6,031,588, G + C content of 60.34, and 5512 total number of putative genes. RAST annotated a total of 542 subsystems in the genome of strain W15Feb9B along with the presence of 5360 coding sequences. A genome wide survey of strain W15Feb9B indicated that it has the potential to degrade several other pollutants including atrazine, caprolactam, dioxin, PAHs (such as naphthalene) and several chloroaromatic compounds.

  17. Whole genome sequence analysis of an Alachlor and Endosulfan degrading Pseudomonas strain W15Feb9B isolated from Ochlockonee River, Florida.

    PubMed

    Chauhan, Ashvini; Pathak, Ashish; Ewida, Ayman Y I; Griffiths, Zabrenna; Stothard, Paul

    2016-06-01

    We recently isolated a Pseudomonas sp. strain W15Feb9B from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides - Alachlor [(2-chloro-2',6'-diethylphenyl-N (methoxymethyl)acetanilide)] and Endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(e)di-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain W15Feb9B, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of strain 2385 has been deposited in GenBank under accession number JTKF00000000; BioSample number SAMN03151543. The sequences obtained from strain 2385 assembled into 192 contigs with a genome size of 6,031,588, G + C content of 60.34, and 5512 total number of putative genes. RAST annotated a total of 542 subsystems in the genome of strain W15Feb9B along with the presence of 5360 coding sequences. A genome wide survey of strain W15Feb9B indicated that it has the potential to degrade several other pollutants including atrazine, caprolactam, dioxin, PAHs (such as naphthalene) and several chloroaromatic compounds. PMID:27330991

  18. Degradation of alachlor and pyrimethanil by combined photo-Fenton and biological oxidation.

    PubMed

    Ballesteros Martín, M M; Sánchez Pérez, J A; García Sánchez, J L; Montes de Oca, L; Casas López, J L; Oller, I; Malato Rodríguez, S

    2008-06-30

    Biodegradability of aqueous solutions of the herbicide alachlor and the fungicide pyrimethanil, partly treated by photo-Fenton, and the effect of photoreaction intermediates on growth and DOC removal kinetics of the bacteria Pseudomonas putida CECT 324 are demonstrated. Toxicity of 30-120 mg L(-1) alachlor and pyrimethanil has been assayed in P. putida. The biodegradability of photocatalytic intermediates found at different photo-treatment times was evaluated for each pesticide. At a selected time during batch-mode phototreatment, larger-scale biodegradation kinetics were analysed in a 12 L bubble column bioreactor. Both alachlor and pyrimethanil are non-toxic for P. putida CECT 324 at the test concentrations, but they are not biodegradable. A approximately 100 min photo-Fenton pre-treatment was enough to enhance biodegradability, the biological oxidation response being dependent on the pesticide tested. The different alachlor and pyrimethanil respiration and carbon uptake rates in pre-treated solutions are related to change in the growth kinetics of P. putida. Reproducible results have shown that P. putida could be a suitable microorganism for determining photo-Fenton pre-treatment time. PMID:18162295

  19. METHOD DEVELOPMENT FOR ALACHLOR ESA AND OTHER ACENTANILIDE HERBICIDE DEGRADATION PRODUCTS

    EPA Science Inventory

    Introduction: Acetanilide herbicides are frequently applied in the U.S. on crops (corn, soybeans, popcorn, etc.) to control broadleaf and annual weeds. The acetanilide and acetamide herbicides currently registered for use in the U.S. are alachlor, acetochlor, metolachlor, propa...

  20. Butachlor degradation in tropical soils: effect of application rate, biotic-abiotic interactions and soil conditions.

    PubMed

    Pal, R; Das, P; Chakrabarti, K; Chakraborty, A; Chowdhury, A

    2006-01-01

    The degradative characteristics of butachlor (N-Butoxymethyl-2-chloro-2',6'-diethyla- cetanilide) were studied under controlled laboratory conditions in clay loam alluvial (AL) soil (Typic udifluvent) and coastal saline (CS) soil (Typic endoaquept) from rice cultivated fields. The application rates included field rate (FR), 2-times FR (2FR) and 10-times FR (10FR). The incubation study was carried out at 30 degrees C with and without decomposed cow manure (DCM) at 60% of maximum water holding capacity (WHC) and waterlogged soil condition. The half-life values depended on the soil types and initial concentrations of butachlor. Butachlor degraded faster in AL soil and in soil amended with DCM under waterlogged condition. Microbial degradation is the major avenue of butachlor degradation from soils.

  1. Action of the herbicide butachlor on cholinesterases in the freshwater snail Pila globosa (Swainson).

    PubMed

    Rajyalakshmi, T; Srinivas, T; Swamy, K V; Prasad, N S; Mohan, P M

    1996-11-01

    Butachlor action on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activates in central nervous tissue of the snail Pila globosa was assayed following the method of ELLMAN et al1, in vitro by adding butachlor directly (10-100 mu moles), to tissue homogenates and in in vivo by exposing the snails to sub-lethal concentration (26.6 ppm) and taking out the tissue for experimentation at different intervals (3, 6, 12, 24 and 48 h) of exposure. The enzyme activities decreased in a dose-dependent manner in vitro, and up to 12-24 h in vivo after which they showed recovery towards the control. The inhibition of cholinesterases by butachlor in vitro indicates a direct action of the herbicide on these enzymes. Presumably butachlor exercises its neurotoxic effects through cholinergic impairment in a way similar to that of organophosphates and carbamates.

  2. Influence of degradation and sorption processes on the persistence and movement of alachlor and dicamba in soils

    SciTech Connect

    Yen, P.Y.

    1992-01-01

    The impact of herbicide usage in agriculture on ground water quality is controlled by the interaction of herbicide degradation, sorption, and transport processes as the herbicide moves through the soil to ground water. The objectives of this thesis were to determine the influence of degradation and sorption processes on the fate of a non-ionic (alachlor) and a weak acid (dicamba) herbicide in four soils (Kim loam, Port Byron silt loam, Webster silty clay loam, and Estherville sandy loam) as a function of soil depth. Alachlor dissipated rapidly under field conditions in Kim soil. Although laboratory studied underestimated the rate of alachlor degradation compared to field conditions, they showed that microbial degradation rather than leaching below sampling depth was the major dissipation pathway of alachlor in soil. Laboratory studies are showed that soils obtained from lower depths had capacities to degrade alachlor, however, at slower rates than surface soils. Sorption of alachlor to soils was moderate (Freundlich sorption coefficient, K[sub f] = 0.7 to 7.3). Movement of alachlor in Kim soil under field conditions was overestimated by leachability indices calculated based on laboratory degradation and sorption studies. Leachability indices would classify alachlor as a [open quotes]leacher[close quotes] in Kim, Port Byron and Estherville soils. In the case of Webster soil, alachlor would be classified as transitional between a [open quotes]leacher[close quotes] and [open quotes]nonleacher[close quotes]. Field dissipation experiments are currently being conducted to evaluate potential leachability of dicamba in the three Minnesota soils. Laboratory studies showed that degradation of dicamba in the four soils was slow (50% dissipation time, DT[sub 50] > 70 days) due to a long lag phase. Soils below 15 cm depth demonstrated slower dicamba degradation capacities than the surface soils. Sorption of dicamba to these soils was minimal (K[sub f] = 0.004 to 0.50).

  3. Construction and analysis of an intergeneric fusant able to degrade bensulfuron-methyl and butachlor.

    PubMed

    Feng, Liping; Xiong, Minghua; Cheng, Xiaosong; Hou, Ning; Li, Chunyan

    2013-02-01

    Rhodococcus sp. BX2 degrades bensulfuron-methyl but not butachlor, and Acinetobacter sp. LYC-1 degrades butachlor but not bensulfuron-methyl. Functional strains were constructed through protoplast fusion of Rhodococcus sp. BX2 and Acinetobacter sp. LYC-1 to generate fusants with an improved ability to simultaneously degrade bensulfuron-methyl and butachlor. Initial identification and stability tests of the fusants were performed. Three fusants with eighth transfer on plates containing two antibiotics and two herbicides were obtained. F1 also grew well in an inorganic salt solution containing bensulfuron-methyl and butachlor. F1 was characterized by its parents' morphological and physio-biochemical features. F1 not only had bands in common with BX2 and LYC-1, but also had its own specific bands analyzed by Random Amplified Polymorphic DNA. The genetic similarity indices between F1 and BX2 and F1 and LYC-1 were 0.507 and 0.470, respectively. The percentages bensulfuron-methyl and butachlor degradation by F1 in an inorganic salt solution supplemented with 100 mg/L bensulfuron-methyl and 100 mg/L butachlor were 65.35 and 62.41 %, respectively, and the percentages in soil contaminated with 10 mg/kg bensulfuron-methyl and 10 mg/kg butachlor with an inoculum size of 5 % at 34 °C and at a pH of 7.5 after 35 days were 63.74 and 61.53 %, respectively. It was demonstrated that F1 could simultaneously degrade bensulfuron-methyl and butachlor.

  4. Combined effects of cadmium and butachlor on soil enzyme activities and microbial community structure

    NASA Astrophysics Data System (ADS)

    Wang, Jinhua; Lu, Yitong; Shen, Guoqing

    2007-02-01

    The combined effects of cadmium (Cd, 10 mg/kg of soil) and butachlor (5, 10 and 50 mg/kg of soil) on enzyme activities and microbial community structure were assessed in phaeozem soil. The result showed that phosphatase activities were decreased in soils with Cd (10 mg/kg of soil) alone whereas urease acitivities were unaffected by Cd. Urease and phosphatase activities were significantly reduced by high butachlor concentration (50 mg/kg of soil). When Cd and butachlor concentrations in soils were added at milligram ratio of 2:1 or 1:2, urease and phosphatase activities were decreased, while enzyme activities were greatly improved at the ratio of 1:5. This study indicates that the combined effects of Cd and butachlor on soil urease and phosphatase activities depend largely on the addition concentration ratios to soils. The random amplified polymorphic DNA (RAPD) analysis showed that the changes occurring in RAPD profiles of different treated samples included variation in loss of normal bands and appearance of new bands compared with the control soil. The RAPD fingerprints showed substantial differences between the control and treated soil samples, with apparent changes in the number and size of amplified DNA fragments. The results showed that the addition of high concentration butachlor and the combined applied Cd and butachlor significantly affected the diversity of microbial community. The present results suggest that RAPD analysis in conjunction with other biomarkers such as soil enzyme parameter etc. would prove a powerful ecotoxicological tool.

  5. Butachlor inhibits production and oxidation of methane in tropical rice soils under flooded condition.

    PubMed

    Mohanty, S R; Nayak, D R; Babu, Y J; Adhya, T K

    2004-01-01

    In laboratory incubation experiments, application of a commercial formulation of the herbicide butachlor (N-butoxymethyl-2-chloro-2',6'-diethyl acetanilide) to three tropical rice soils, widely differing in their physicochemical characteristics, under flooded condition inhibited methane (CH4) production. The inhibitory effect was concentration dependent and most remarkable in the alluvial soil. Thus, following application of butachlor at 5, 10, 50 and 100 microg g(-1) soil, respectively, cumulative CH4 production in the alluvial soil was inhibited by 15%, 31%, 91% and 98% over unamended control. Since CH4 production was less pronounced in the sandy loam and acid sulfate soil, the impact of amendment with butchalor, albeit inhibitory, was less extensive than the alluvial soil. Inhibition of CH4 production in butachlor-amended alluvial soil was related to the prevention in the drop in redox potential as well as low methanogenic bacterial population especially at high concentrations of butachlor. CH4 oxidation was also inhibited in butachlor-amended alluvial soil with the inhibitory effect being more prevalent under flooded condition. Inhibition in CH4 oxidation was related to a reduction in the population of soluble methane monooxygenase producing methanotrophs. Results demonstrate that butachlor, a commonly used herbicide in rice cultivation, even at very low concentrations can affect CH4 production and its oxidation, thereby influencing the biogeochemical cycle of CH4 in flooded rice soils.

  6. Phylogenetic changes in soil microbial and diazotrophic diversity with application of butachlor.

    PubMed

    Yen, Jui-Hung; Wang, Yei-Shung; Hsu, Wey-Shin; Chen, Wen-Ching

    2013-01-01

    We investigated changes in population and taxonomic distribution of cultivable bacteria and diazotrophs with butachlor application in rice paddy soils. Population changes were measured by the traditional plate-count method, and taxonomic distribution was studied by 16S rDNA sequencing, then maximum parsimony phylogenic analysis with bootstrapping (1,000 replications). The bacterial population was higher after 39 than 7 days of rice cultivation, which indicated the augmentation of soil microbes by rice root exudates. The application of butachlor increased the diazotrophic population in both upper (0-3 cm) and lower (3-15 cm) layers of soils. Especially at day 39, the population of diazotrophs was 1.8 and 1.6 times that of the control in upper and lower layer soils, respectively. We found several bacterial strains only with butachlor application; examples are strains closest to Bacillus arsenicus, B. marisflavi, B. luciferensis, B. pumilus, and Pseudomonas alvei. Among diazotrophs, three strains closely related to Streptomyces sp. or Rhrizobium sp. were found only with butachlor application. The population of cultivable bacteria and the species composition were both changed with butachlor application, which explains in part the contribution of butachlor to augmenting soil nitrogen-fixing ability.

  7. Biotransformation of butachlor through mercapturic acid pathway in rat tissue homogenates.

    PubMed

    Ou, Y H; Lin, J K

    1992-01-01

    The metabolism of butachlor was studied in rat liver and kidney homogenates. In vitro incubation of butachlor with liver fractions (S9, microsome, and cytosolic fractions) formed a considerable amount of butachlor glutathione conjugate (BGSC), while the conjugating activity was not efficient for the kidney S9 fraction. There is a sex difference in the distribution of glutathione S-transferase in the liver. It seems that more enzyme activity is detected in the female liver microsome, while this is not the case in its cytosolic fraction. Further biotransformation of BGSC to mercapturate was not observed in the liver S9 fraction. This metabolite was further transformed to butachlor acetyl cysteine conjugate (BACC) in the presence of acetyl CoA, but to butachlor cysteine conjugate (BCC) in the absence of acetyl CoA. These findings demonstrated that butachlor is initially conjugated with GSH to form BGSC by the enzyme glutathione S-transferase in the liver. This metabolite is apparently transported to the kidneys, where it is transformed to the mercapturate.

  8. Introduction of atrazine degrader to enhance rhizodegradation of atrazine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introducing atrazine (ATR) degraders into riparian vegetative buffer strips (VBS) can be a promising bioremediation approach to accelerate the degradation of ATR and its degradation products deposited into VBS by surface runoff. A growth chamber study was conducted to investigated the synergistic ef...

  9. Atrazine leaching from biochar-amended soils.

    PubMed

    Delwiche, Kyle B; Lehmann, Johannes; Walter, M Todd

    2014-01-01

    The herbicide atrazine is used extensively throughout the United States, and is a widespread groundwater and surface water contaminant. Biochar has been shown to strongly sorb organic compounds and could be used to reduce atrazine leaching. We used lab and field experiments to determine biochar impacts on atrazine leaching under increasingly heterogeneous soil conditions. Application of pine chip biochar (commercially pyrolyzed between 300 and 550 °C) reduced cumulative atrazine leaching by 52% in homogenized (packed) soil columns (p=0.0298). Biochar additions in undisturbed soil columns did not significantly (p>0.05) reduce atrazine leaching. Mean peak groundwater atrazine concentrations were 53% lower in a field experiment after additions of 10 t ha(-1) acidified biochar (p=0.0056) relative to no biochar additions. Equivalent peat applications by dry mass had no effect on atrazine leaching. Plots receiving a peat-biochar mixture showed no reduction, suggesting that the peat organic matter may compete with atrazine for biochar sorption sites. Several individual measurement values outside the 99% confidence interval in perched groundwater concentrations indicate that macropore structure could contribute to rare, large leaching events that are not effectively reduced by biochar. We conclude that biochar application has the potential to decrease peak atrazine leaching, but heterogeneous soil conditions, especially preferential flow paths, may reduce this impact. Long-term atrazine leaching reductions are also uncertain. PMID:24129000

  10. Atrazine leaching from biochar-amended soils.

    PubMed

    Delwiche, Kyle B; Lehmann, Johannes; Walter, M Todd

    2014-01-01

    The herbicide atrazine is used extensively throughout the United States, and is a widespread groundwater and surface water contaminant. Biochar has been shown to strongly sorb organic compounds and could be used to reduce atrazine leaching. We used lab and field experiments to determine biochar impacts on atrazine leaching under increasingly heterogeneous soil conditions. Application of pine chip biochar (commercially pyrolyzed between 300 and 550 °C) reduced cumulative atrazine leaching by 52% in homogenized (packed) soil columns (p=0.0298). Biochar additions in undisturbed soil columns did not significantly (p>0.05) reduce atrazine leaching. Mean peak groundwater atrazine concentrations were 53% lower in a field experiment after additions of 10 t ha(-1) acidified biochar (p=0.0056) relative to no biochar additions. Equivalent peat applications by dry mass had no effect on atrazine leaching. Plots receiving a peat-biochar mixture showed no reduction, suggesting that the peat organic matter may compete with atrazine for biochar sorption sites. Several individual measurement values outside the 99% confidence interval in perched groundwater concentrations indicate that macropore structure could contribute to rare, large leaching events that are not effectively reduced by biochar. We conclude that biochar application has the potential to decrease peak atrazine leaching, but heterogeneous soil conditions, especially preferential flow paths, may reduce this impact. Long-term atrazine leaching reductions are also uncertain.

  11. Effect of cadmium alone and in combination with butachlor on soil enzymes.

    PubMed

    Wang, Jinhua; Lu, Yitong; Ding, Hui; Shen, Guoqing

    2007-10-01

    The ecological toxicity of cadmium (Cd, 10 mg kg(-1 )of dry weight soil) and butachlor (10, 50 and100 mg kg(-1 )of dry weight soil) in both their single and combined effects on soil urease and phosphatase was studied after 1, 3, 7, 14, 21 and 28 days exposure under controlled conditions in paddy and phaeozem soils. The results showed that Cd reduced the activities of urease and phosphatase at early incubation time (1-7 days), while the reduction almost disappeared at the end of the incubation. The effect of Cd on phosphatase was more pronounced than that on urease. The activities of urease and phosphatase were reduced by butachlor, while urease activity was significantly (P < 0.05 or P < 0.01) improved when the concentrations of butachlor were 10 and 50 mg kg(-1) at the end of the incubation. When Cd (10 mg kg(-1)) was combined with butachlor (50 and 100 mg kg(-1)), the activities of urease and phosphatase became lower than without combination at early incubation time, which indicated that the toxicity of Cd significantly increased (P < 0.05 or P < 0.01). However, when Cd (10 mg kg(-1)) was combined with butachlor (10 mg kg(-1)), the activities of urease and phosphatase became higher than those without combination at the end of the incubation, which indicated that the toxicity of Cd decreased. It was indicated that the combined effects depended largely on the incubation time and the concentration ratio of Cd and butachlor. In addition, it was showed that the combined effects of butachlor and Cd appeared different in paddy from phaeozem, which may be related to the different properties of these soils.

  12. (1)H NMR based metabolomics approach to study the toxic effects of herbicide butachlor on goldfish (Carassius auratus).

    PubMed

    Xu, Hua-Dong; Wang, Jun-Song; Li, Ming-Hui; Liu, Yan; Chen, Ting; Jia, Ai-Qun

    2015-02-01

    Butachlor, one of the most widely used herbicides in agriculture, has been reported with high ecotoxicity to aquatic plants and animals. In this study, a (1)H NMR based metabolomics approach combined with histopathological examination and biochemical assays was applied to comprehensively investigate the toxic effects of butachlor on four important organs (gill, brain, liver and kidney) of goldfish (Carassius auratus) for the first time. After 10 days' butachlor exposure at two dosages of 3.2 and 0.64 μmol/L, fish tissues (gill, brain, liver and kidney) and serum were collected. Histopathological inspection revealed severe impairment of gill filaments and obvious cellular edema in livers and kidneys. The increase of glutathione peroxidase (GSH-Px) activity in gill and methane dicarboxylic aldehyde (MDA) level in four tissues reflected the disturbance of antioxidative system in the intoxicated goldfish. Serum lactate dehydrogenase (LDH) activity and creatinine (CRE) level were increased in butachlor exposure groups, suggesting liver and kidney injuries induced by butachlor. Orthogonal signal correction partial least-squares discriminant analysis (OSC-PLS-DA) of NMR profiles disclosed metabolic changes that were related to the toxic effects of butachlor including oxidative stress, disorder of energy metabolism and amino acids metabolism, and disturbance of neurotransmitter balance in butachlor exposed goldfish. This integrated metabolomics approach provided a molecular basis underlying the toxicity of butachlor and demonstrated that metabolomics was a powerful and highly effective approach to elucidate the toxicity and underlying mechanisms of herbicides and pesticides, applicable for their risk assessment. PMID:25528421

  13. (1)H NMR based metabolomics approach to study the toxic effects of herbicide butachlor on goldfish (Carassius auratus).

    PubMed

    Xu, Hua-Dong; Wang, Jun-Song; Li, Ming-Hui; Liu, Yan; Chen, Ting; Jia, Ai-Qun

    2015-02-01

    Butachlor, one of the most widely used herbicides in agriculture, has been reported with high ecotoxicity to aquatic plants and animals. In this study, a (1)H NMR based metabolomics approach combined with histopathological examination and biochemical assays was applied to comprehensively investigate the toxic effects of butachlor on four important organs (gill, brain, liver and kidney) of goldfish (Carassius auratus) for the first time. After 10 days' butachlor exposure at two dosages of 3.2 and 0.64 μmol/L, fish tissues (gill, brain, liver and kidney) and serum were collected. Histopathological inspection revealed severe impairment of gill filaments and obvious cellular edema in livers and kidneys. The increase of glutathione peroxidase (GSH-Px) activity in gill and methane dicarboxylic aldehyde (MDA) level in four tissues reflected the disturbance of antioxidative system in the intoxicated goldfish. Serum lactate dehydrogenase (LDH) activity and creatinine (CRE) level were increased in butachlor exposure groups, suggesting liver and kidney injuries induced by butachlor. Orthogonal signal correction partial least-squares discriminant analysis (OSC-PLS-DA) of NMR profiles disclosed metabolic changes that were related to the toxic effects of butachlor including oxidative stress, disorder of energy metabolism and amino acids metabolism, and disturbance of neurotransmitter balance in butachlor exposed goldfish. This integrated metabolomics approach provided a molecular basis underlying the toxicity of butachlor and demonstrated that metabolomics was a powerful and highly effective approach to elucidate the toxicity and underlying mechanisms of herbicides and pesticides, applicable for their risk assessment.

  14. Mortality and cancer incidence among alachlor manufacturing workers 1968–99

    PubMed Central

    Acquavella, J; Delzell, E; Cheng, H; Lynch, C; Johnson, G

    2004-01-01

    Background: Alachlor is the active ingredient in pre-emergent herbicide formulations that have been used widely on corn, soybeans, and other crops. It has been found to cause nasal, stomach, and thyroid tumours in rodent feeding studies at levels that are much higher than likely human exposures. Aims: To evaluate mortality rates from 1968 to 1999 and cancer incidence rates from 1969 to 1999 for alachlor manufacturing workers at a plant in Muscatine, Iowa. Methods: Worker mortality and cancer incidence rates were compared to corresponding rates for the Iowa state general population. Analyses addressed potential intensity and duration of exposure. Results: For workers with any period of high alachlor exposure, mortality from all causes combined was lower than expected (42 observed deaths, SMR 64, 95% CI 46 to 86) and cancer mortality was slightly lower than expected (13 observed deaths, SMR 79, 95% CI 42 to 136). Cancer incidence for workers with potential high exposure was similar to that for Iowa residents, both overall (29 observed cases, SIR 123, 95% CI 82 to 177) and for workers exposed for five or more years and with at least 15 years since first exposure (eight observed cases, SIR 113, 95% CI 49 to 224). There were no cases of nasal, stomach, or thyroid cancer. Conclusions: There were no cancers of the types found in toxicology studies and no discernible relation between cancer incidence for any site and years of alachlor exposure or time since first exposure. Despite the small size of this population, the findings are important because these workers had chronic exposure potential during extended manufacturing campaigns, while use in agriculture is typically limited to a few days or weeks each year. PMID:15258274

  15. Cometabolism of low concentrations of propachlor, alachlor, and cycloate in sewage and lake water.

    PubMed Central

    Novick, N J; Alexander, M

    1985-01-01

    Low concentrations of propachlor (2-chloro-N-isopropylacetanilide) and alachlor [2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide] were not mineralized, cycloate (S-ethyl-N-ethylthiocyclohexanecarbamate) was slowly or not mineralized, and aniline and cyclohexylamine were readily mineralized in sewage and lake water. Propachlor, alachlor, and cycloate were extensively metabolized, but the products were organic. Little conversion of propachlor and alachlor was evident in sterilized sewage or lake water. The cometabolism of propachlor was essentially linear with time in lake water and was well fit by zero-order kinetics in short periods and by first-order kinetics in longer periods in sewage. The rate of cometabolism in sewage was directly proportional to propachlor concentration at levels from 63 pg/ml to more than 100 ng/ml. Glucose but not aniline increased the yield of products formed during propachlor cometabolism in sewage. No microorganism able to use propachlor as a sole source of carbon and energy was isolated, but bacteria isolated from sewage and lake water metabolized this chemical. During the metabolism of this herbicide by two of the bacteria, none of the carbon was assimilated. Our data indicate that cometabolism of these pesticides takes place at concentrations of synthetic compounds that commonly occur in natural waters. PMID:4004208

  16. Soil mesocosm studies on atrazine bioremediation.

    PubMed

    Sagarkar, Sneha; Nousiainen, Aura; Shaligram, Shraddha; Björklöf, Katarina; Lindström, Kristina; Jørgensen, Kirsten S; Kapley, Atya

    2014-06-15

    Accumulation of pesticides in the environment causes serious issues of contamination and toxicity. Bioremediation is an ecologically sound method to manage soil pollution, but the bottleneck here, is the successful scale-up of lab-scale experiments to field applications. This study demonstrates pilot-scale bioremediation in tropical soil using atrazine as model pollutant. Mimicking field conditions, three different bioremediation strategies for atrazine degradation were explored. 100 kg soil mesocosms were set-up, with or without atrazine application history. Natural attenuation and enhanced bioremediation were tested, where augmentation with an atrazine degrading consortium demonstrated best pollutant removal. 90% atrazine degradation was observed in six days in soil previously exposed to atrazine, while soil without history of atrazine use, needed 15 days to remove the same amount of amended atrazine. The bacterial consortium comprised of 3 novel bacterial strains with different genetic atrazine degrading potential. The progress of bioremediation was monitored by measuring the levels of atrazine and its intermediate, cyanuric acid. Genes from the atrazine degradation pathway, namely, atzA, atzB, atzD, trzN and trzD were quantified in all mesocosms for 60 days. The highest abundance of all target genes was observed on the 6th day of treatment. trzD was observed in the bioaugmented mesocosms only. The bacterial community profile in all mesocosms was monitored by LH-PCR over a period of two months. Results indicate that the communities changed rapidly after inoculation, but there was no drastic change in microbial community profile after 1 month. Results indicated that efficient bioremediation of atrazine using a microbial consortium could be successfully up-scaled to pilot scale.

  17. Responses of butachlor degradation and microbial properties in a riparian soil to the cultivation of three different plants.

    PubMed

    Yang, Changming; Wang, Mengmeng; Chen, Haiyan; Li, Jianhua

    2011-01-01

    A pot experiment was conducted to investigate the biodegradation dynamics and related microbial ecophysiological responses to butachlor addition in a riparian soil planted with different plants such as Phragmites australis, Zizania aquatica, and Acorus calamus. The results showed that there were significant differences in microbial degradation dynamics of butachlor in the rhizosphere soils among the three riparian plants. A. calamus displays a significantly higher degradation efficiency of butachlor in the rhizosphere soils, as compared with Z. aquatica and P. australis. Half-life time of butachlor degradation in the rhizospheric soils of P. australis, Z. aquatica, and A. calamus were 7.5, 9.8 and 5.4 days, respectively. Residual butachlor concentration in A. calamus rhizosphere soil was 35.2% and 21.7% lower than that in Z. aquatica and P. australis rhizosphere soils, respectively, indicating that A. calamus showed a greater improvement effect on biodegradation of butachlor in rhizosphere soils than the other two riparian plant. In general, microbial biomass and biochemical activities in rhizosphere soils were depressed by butachlor addition, despite the riparian plant types. However, rhizospheric soil microbial ecophysiological responses to butachlor addition significantly (P < 0.05) differed between riparian plant species. Compared to Z. aquatica and P. australis, A. calamus showed significantly larger microbial number, higher enzyme activities and soil respiration rates in the rhizosphere soils. The results indicated that A. calamus have a better alleviative effect on inhibition of microbial growth due to butachlor addition and can be used as a suitable riparian plant for detoxifying and remediating butachlor contamination from agricultural nonpoint pollution.

  18. Absorption and metabolism of 2-chloro-2,6-diethyl-N-(butoxymethyl)acetanilide (butachlor) in human skin in vitro.

    PubMed

    Ademola, J I; Wester, R C; Maibach, H I

    1993-07-01

    Studies have demonstrated that several chemicals are absorbed and metabolized during skin permeation. We investigated the absorption and metabolism of the pesticide butachlor. Radiolabeled butachlor was measured in human (n = 5) skin and the unchanged compound and metabolites were quantified by high-pressure liquid chromatography (HPLC) and thin-layer chromatography (TLC). Following a 24-hr exposure, an average butachlor quantity of approximately 5.00% of the applied dose (1.01 micrograms) was absorbed by the skin. The mean peak penetration rate was 0.7% of the applied dose per hour. The skin retained 1.40 to 8.10% of the applied butachlor. The retention of 1.4 to 8.1% of the pesticide by the skin suggests the importance of monitoring human skin following topical exposure. Of the dose recovered in the skin, 0.9% was metabolized to 4-hydroxybutachlor, while 1.8% of the dose in the receptor fluid was recovered as polar conjugates (cysteine, 0.29% dose; glutathione, 0.1% dose; unidentified metabolites, 1.4% dose); 2.8 and 6.8% of the dose absorbed by the skin (approximately 5.0%) were recovered as metabolites in the receptor fluids and skin homogenates, respectively. Similar to metabolism during percutaneous absorption, butachlor was metabolized to its conjugated and hydroxyl derivatives by skin fractions. The rate of butachlor glutathione and butachlor cysteine formation using skin cytosolic fractions were 12.0 +/- 1.5 and 48.0 +/- 3.6 pmol/min/mg protein +/- SD, respectively. When human skin microsomes were incubated with butachlor, 4-hydroxybutachlor was formed at the rate of 55.0 +/- 15.0 pmol/min/mg protein +/- SD. 4-Hydroxybutachlor formation was totally dependent on the presence of NADPH. The biotransformation of butachlor using skin fractions indicates the metabolic capacity of the tissue. The biological significance of these metabolites in the disposition of butachlor requires further investigation.

  19. Clastogenicity of pentachlorophenol, 2,4-D and butachlor evaluated by Allium root tip test.

    PubMed

    Ateeq, Bushra; Abul Farah, M; Niamat Ali, M; Ahmad, Waseem

    2002-02-15

    The meristematic mitotic cells of Allium cepa is an efficient cytogenetic material for chromosome aberration assay on environmental pollutants. For assessing genotoxicity of pentachlorophenol (PCP), 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-chloro-2,6-diethyl-N-(butoxymethyl) acetanilide (butachlor), 50% effective concentration (EC(50)), c-mitosis, stickiness, chromosome breaks and mitotic index (MI) were used as endpoints of genotoxicity. EC(50) values for PCP and butachlor are 0.73 and 5.13 ppm, respectively. 2,4-D evidently induced morphological changes at higher concentrations. Some changes like crochet hooks, c-tumours and broken roots were unique to 2,4-D at 5-20 ppm. No such abnormalities were found in PCP and butachlor treated groups, however, root deteriorated and degenerated at higher concentrations (<3 ppm) in PCP. MI in 2,4-D showed a low average of 14.32% followed by PCP (19.53%), while in butachlor it was recorded 71.6%, which is near to the control value. All chemicals induced chromosome aberrations at statistically significant level. The highest chromosome aberration frequency (11.90%) was recorded in PCP at 3 ppm. Large number of c-mitotic anaphases indicated that butachlor acts as potent spindle inhibitor, whereas, breaks, bridges, stickiness and laggards were most frequently found in PCP showing that it is a potent clastogen. PMID:11815249

  20. Identification of UV photoproducts and hydrolysis products of butachlor by mass spectrometry.

    PubMed

    Zheng, H H; Ye, C M

    2001-07-15

    The photoproducts and hydrolysis products of butachlor in water were identified by gas chromatography/mass spectrometry. When exposed to UV light, butachlor in aqueous solution was rapidly degraded, giving at least 11 photoproducts as a result of dechlorination with subsequent hydroxylation or cyclization processes. The chemical structures of nine degradation compounds were identified on the basis of mass spectrum interpretation and literature data. Major photoproducts are identified as 8-ethyl-1-butoxymethyl-4-methyl-2-oxo-1,2,3,4-tetrahydro-quinoline, 2-hydroxy-2',6'-diethyl-N-(butoxymethyl) acetanilide, and a compound related to butachlor. Minor photoproducts are identified as 2,6-diethylaniline; 1-acetyl-7-ethylindole; N-(2,6-diethylphenyl)-N-(butoxymethyl)acetamide; 2-oxo-N-(2,6-diethyl-phenyl)-N-(butoxymethyl)acetamide; 1-hydroxyacetyl-2-butoxyl-3-methyl-7-ethylindole; 1-acetyl-2-butoxyl-3-methyl-7-ethylindole; and two compounds with the chemical structure unknown. The half-lives of butachlor UV photolysis were 7.54, 10.56, and 12.22 min in deionized water, river water, and paddy water, respectively. The half-lives of butachlor hydrolysis at pH 4, 7, and 10 were 630, 1155, and 1155 days at 25 +/- 1 degrees C, respectively. A hydrolysis product at pH 4 was identified by GC/MS to be 2-hydroxy-2',6'-diethyl-N-(butoxymethyl) acetanilide.

  1. Clastogenicity of pentachlorophenol, 2,4-D and butachlor evaluated by Allium root tip test.

    PubMed

    Ateeq, Bushra; Abul Farah, M; Niamat Ali, M; Ahmad, Waseem

    2002-02-15

    The meristematic mitotic cells of Allium cepa is an efficient cytogenetic material for chromosome aberration assay on environmental pollutants. For assessing genotoxicity of pentachlorophenol (PCP), 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-chloro-2,6-diethyl-N-(butoxymethyl) acetanilide (butachlor), 50% effective concentration (EC(50)), c-mitosis, stickiness, chromosome breaks and mitotic index (MI) were used as endpoints of genotoxicity. EC(50) values for PCP and butachlor are 0.73 and 5.13 ppm, respectively. 2,4-D evidently induced morphological changes at higher concentrations. Some changes like crochet hooks, c-tumours and broken roots were unique to 2,4-D at 5-20 ppm. No such abnormalities were found in PCP and butachlor treated groups, however, root deteriorated and degenerated at higher concentrations (<3 ppm) in PCP. MI in 2,4-D showed a low average of 14.32% followed by PCP (19.53%), while in butachlor it was recorded 71.6%, which is near to the control value. All chemicals induced chromosome aberrations at statistically significant level. The highest chromosome aberration frequency (11.90%) was recorded in PCP at 3 ppm. Large number of c-mitotic anaphases indicated that butachlor acts as potent spindle inhibitor, whereas, breaks, bridges, stickiness and laggards were most frequently found in PCP showing that it is a potent clastogen.

  2. Degradation mechanism of alachlor during direct ozonation and O(3)/H(2)O(2) advanced oxidation process.

    PubMed

    Qiang, Zhimin; Liu, Chao; Dong, Bingzhi; Zhang, Yalei

    2010-01-01

    The degradation of alachlor by direct ozonation and advanced oxidation process O(3)/H(2)O(2) was investigated in this study with focus on identification of degradation byproducts. The second-order reaction rate constant between ozone and alachlor was determined to be 2.5+/-0.1M(-1)s(-1) at pH 7.0 and 20 degrees C. Twelve and eight high-molecular-weight byproducts (with the benzene ring intact) from alachlor degradation were identified during direct ozonation and O(3)/H(2)O(2), respectively. The common degradation byproducts included N-(2,6-diethylphenyl)-methyleneamine, 8-ethyl-3,4-dihydro-quinoline, 8-ethyl-quinoline, 1-chloroacetyl-2-hydro-3-ketone-7-acetyl-indole, 2-chloro-2',6'-diacetyl-N-(methoxymethyl)acetanilide, 2-chloro-2'-acetyl-6'-ethyl-N-(methoxymethyl)-acetanilide, and two hydroxylated alachlor isomers. In direct ozonation, four more byproducts were also identified including 1-chloroacetyl-2,3-dihydro-7-ethyl-indole, 2-chloro-2',6'-ethyl-acetanilide, 2-chloro-2',6'-acetyl-acetanilide and 2-chloro-2'-ethyl-6'-acetyl-N-(methoxymethyl)-acetanilide. Degradation of alachlor by O(3) and O(3)/H(2)O(2) also led to the formation of low-molecular-weight byproducts including formic, acetic, propionic, monochloroacetic and oxalic acids as well as chloride ion (only detected in O(3)/H(2)O(2)). Nitrite and nitrate formation was negligible. Alachlor degradation occurred via oxidation of the arylethyl group, N-dealkylation, cyclization and cleavage of benzene ring. After O(3) or O(3)/H(2)O(2) treatment, the toxicity of alachlor solution examined by the Daphnia magna bioassay was slightly reduced. PMID:20022076

  3. Accelerated degradation of 14C-atrazine in an atrazine adapted field soil from Belgium

    NASA Astrophysics Data System (ADS)

    Hamacher, Georg; Jablonowski, Nicolai David; Martinazzo, Rosane; Accinelli, Cesare; Köppchen, Stephan; Langen, Ulrike; Linden, Andreas; Krause, Martina; Burauel, Peter

    2010-05-01

    Atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] is one of the most widely used herbicides in the world. Atrazine is considered to be mobile in soil and has often been characterized as a rather recalcitrant compound in the environment. In the present study the accelerated atrazine degradation in an agriculturally used soil was examined. Soil samples were collected from a Belgian field which was used for corn-plantations and was regularly treated with atrazine during the last 30 years. The experiment was conducted under controlled laboratory conditions (GLP) using 14C-labelled and unlabelled atrazine in accordance to the reported field application dose of 1 mg kg-1. Triplicates of treated subsamples were incubated at 50% WHCmax and under slurry conditions (1:4 soil:solution ratio, using distilled water) in the dark at 20° C. Control samples were collected at an adjacent pear orchard where no atrazine or other triazine pesticides application was reported. After 92 days of incubation, the mineralized amount of atrazine reached 83% of the initially applied 14C-activity in the atrazine treated soil for the slurry setup. A maximum of atrazine mineralization was observed in the treated field soil between 6 and 7 days of incubation for both, 50% WHCmax and slurry setups. The total 14C-atrazine mineralization was equally high for 50% WHCmax in the atrazine treated soil. After an extended lag-phase in comparison to the treated soil the overall mineralization of 14C-atrazine of 81% was observed in the atrazine untreated soil under slurry conditions. This observation might be due to a possible cross adaption of the microflora. These results could be attributed to an atrazine drift during application since the control samples were taken in an adjacent pear orchard with no atrazine application history. These results demonstrate an adaption of the microflora to mineralize atrazine rapidly. The formation of desorbable metabolites as well as the formation of

  4. Effects of herbicide butachlor on soil microorganisms and on nitrogen-fixing abilities in paddy soil.

    PubMed

    Chen, Wen-Ching; Yen, Jui-Hung; Chang, Ching-Shu; Wang, Yei-Shung

    2009-01-01

    The composition of culture-independent microbial communities and the change of nitrogenase activities under the application of butachlor in paddy soil were investigated. Nitrogen-fixation ability was expressed by the amount of acetylene reduction, and changes of microbial communities were studied by using denaturing gradient gel electrophoresis (DGGE) technique; afterward, minimum distance (MD, in brief) statistics was applied to determine the cluster numbers in UPGMA dendrograms. The results showed that the reduction of acetylene was suppressed shortly after butachlor application but was augmented after 37 days in both upper and lower layer soils. From UPGMA dendrograms, the diazotrophic divergences ranged from 33% to 64% throughout rice growth stages. For general bacterial communities, the diversities ranged from 28% to 52%. The divergences became higher with the cultivation period, and the application of butachlor imposed a significant variation on microbial community shift, which may be a reason for the boosting nitrogen-fixation ability in paddy soils.

  5. Experimental design approach to the optimization of ultrasonic degradation of alachlor and enhancement of treated water biodegradability.

    PubMed

    Torres, Ricardo A; Mosteo, Rosa; Pétrier, Christian; Pulgarin, Cesar

    2009-03-01

    This work presents the application of experimental design for the ultrasonic degradation of alachlor which is pesticide classified as priority substance by the European Commission within the scope of the Water Framework Directive. The effect of electrical power (20-80W), pH (3-10) and substrate concentration (10-50mgL(-1)) was evaluated. For a confidential level of 90%, pH showed a low effect on the initial degradation rate of alachlor; whereas electrical power, pollutant concentration and the interaction of these two parameters were significant. A reduced model taking into account the significant variables and interactions between variables has shown a good correlation with the experimental results. Additional experiments conducted in natural and deionised water indicated that the alachlor degradation by ultrasound is practically unaffected by the presence of potential *OH radical scavengers: bicarbonate, sulphate, chloride and oxalic acid. In both cases, alachlor was readily eliminated ( approximately 75min). However, after 4h of treatment only 20% of the initial TOC was removed, showing that alachlor by-products are recalcitrant to the ultrasonic action. Biodegradability test (BOD5/COD) carried out during the course of the treatment indicated that the ultrasonic system noticeably increases the biodegradability of the initial solution. PMID:18930694

  6. Impacts of the herbicide butachlor on the larvae of a paddy field breeding frog (Fejervarya limnocharis) in subtropical Taiwan.

    PubMed

    Liu, Wan-Yi; Wang, Ching-Yuh; Wang, Tsu-Shing; Fellers, Gary M; Lai, Bo-Chi; Kam, Yeong-Choy

    2011-03-01

    Butachlor is the most commonly used herbicide on paddy fields in Taiwan and throughout Southeast Asia. Since paddy fields provide habitat for pond breeding amphibians, we examined growth, development, time to metamorphosis, and survival of alpine cricket frog tadpoles (Fejervarya limnocharis) exposed to environmentally realistic concentrations of butachlor. We documented negative impacts of butachlor on survival, development, and time to metamorphosis, but not on tadpole growth. The 96 h LC(50) for tadpoles was 0.87 mg/l, much lower than the 4.8 mg/l recommended dosage for application to paddy fields. Even given the rapid breakdown of butachlor, tadpoles would be exposed to concentrations in excess of their 96 h LC(50) for an estimated 126 h. We also documented DNA damage (genotoxicity) in tadpoles exposed to butachlor at concentrations an order of magnitude less than the 4.8 mg/l recommended application rate. We did not find that butachlor depressed cholinesterase activity of tadpoles, unlike most organophosphorus insecticides. We conclude that butachlor is likely to have widespread negative impacts on amphibians occupying paddy fields with traditional herbicide application.

  7. Impacts of the herbicide butachlor on the larvae of a paddy field breeding frog (Fejervarya limnocharis) in subtropical Taiwan

    USGS Publications Warehouse

    Liu, Wan-Yi; Wang, Ching-Yuh; Wang, Tsu-Shing; Fellers, Gary M.; Lai, Bo-Chi; Kam, Yeong-Choy

    2011-01-01

    Butachlor is the most commonly used herbicide on paddy fields in Taiwan and throughout Southeast Asia. Since paddy fields provide habitat for pond breeding amphibians, we examined growth, development, time to metamorphosis, and survival of alpine cricket frog tadpoles (Fejervarya limnocharis) exposed to environmentally realistic concentrations of butachlor. We documented negative impacts of butachlor on survival, development, and time to metamorphosis, but not on tadpole growth. The 96 h LC50 for tadpoles was 0.87 mg/l, much lower than the 4.8 mg/l recommended dosage for application to paddy fields. Even given the rapid breakdown of butachlor, tadpoles would be exposed to concentrations in excess of their 96 h LC50 for an estimated 126 h. We also documented DNA damage (genotoxicity) in tadpoles exposed to butachlor at concentrations an order of magnitude less than the 4.8 mg/l recommended application rate. We did not find that butachlor depressed cholinesterase activity of tadpoles, unlike most organophosphorus insecticides. We conclude that butachlor is likely to have widespread negative impacts on amphibians occupying paddy fields with traditional herbicide application.

  8. BIODEGRADATION OF ATRAZINE IN SUBSURFACE ENVIRONMENTS

    EPA Science Inventory

    The pesticide atrazine is frequently detected in ground water, including ground water used as drinking water. Little information is available on the fate of atrazine in the subsurface, including its biodegradability. The objectives of this study were to evaluate the biodegradabil...

  9. Butachlor induced dissipation of mitochondrial membrane potential, oxidative DNA damage and necrosis in human peripheral blood mononuclear cells.

    PubMed

    Dwivedi, Sourabh; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A; Musarrat, Javed

    2012-12-01

    Butachlor is a systemic herbicide widely applied on rice, tea, wheat, beans and other crops; however, it concurrently exerts toxic effects on beneficial organisms like earthworms, aquatic invertebrates and other non-target animals including humans. Owing to the associated risk to humans, this chloroacetanilide class of herbicide was investigated with the aim to assess its potential for the (i) interaction with DNA, (ii) mitochondria membrane damage and DNA strand breaks and (iii) cell cycle arrest and necrosis in butachlor treated human peripheral blood mononuclear (PBMN) cells. Fluorescence quenching data revealed the binding constant (Ka=1.2×10(4)M(-1)) and binding capacity (n=1.02) of butachlor with ctDNA. The oxidative potential of butachlor was ascertained based on its capacity of inducing reactive oxygen species (ROS) and substantial amounts of promutagenic 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) adducts in DNA. Also, the discernible butachlor dose-dependent reduction in fluorescence intensity of a cationic dye rhodamine (Rh-123) and increased fluorescence intensity of 2',7'-dichlorodihydro fluorescein diacetate (DCFH-DA) in treated cells signifies decreased mitochondrial membrane potential (ΔΨm) due to intracellular ROS generation. The comet data revealed significantly greater Olive tail moment (OTM) values in butachlor treated PBMN cells vs untreated and DMSO controls. Treatment of cultured PBMN cells for 24h resulted in significantly increased number of binucleated micronucleated (BNMN) cells with a dose dependent reduction in the nuclear division index (NDI). The flow cytometry analysis of annexin V(-)/7-AAD(+) stained cells demonstrated substantial reduction in live population due to complete loss of cell membrane integrity. Overall the data suggested the formation of butachlor-DNA complex, as an initiating event in butachlor-induced DNA damage. The results elucidated the oxidative role of butachlor in intracellular ROS production, and

  10. Pesticides in ground water: Do atrazine metabolites matter?

    USGS Publications Warehouse

    Liu, S.; Yen, S.T.; Kolpin, D.W.

    1996-01-01

    Atrazine and atrazine-residue (atrazine + two metabolites - deethylatrazine and deisopropylatrazine) concentrations were examined to determine if consideration of these atrazine metabolites substantially adds to our understanding of the distribution of this pesticide in groundwater of the midcontinental United States. The mean of atrazine.residue concentrations was 53 percent greater than that of atrazine alone for those observations above the detection limit (> 0.05 μg/l). Furthermore, a censored regression analysis using atrazine-residue concentrations revealed significant factors not identified when only atrazine concentrations were used. Thus, knowledge of concentrations of these atrazine metabolites is required to obtain a true estimation of risk of using these aquifers as sources for drinking water, and such knowledge also provides information that ultimately may be important for future management policies designed to reduce atrazine concentrations in ground water.

  11. Soil microbial community toxic response to atrazine and its residues under atrazine and lead contamination.

    PubMed

    Chen, Qinglin; Yang, Baoshan; Wang, Hui; He, Fei; Gao, Yongchao; Scheel, Ryan A

    2015-01-01

    Intensive use of atrazine and extensive dispersal of lead (Pb) have occurred in farmland with chemical agriculture development. However, the toxicological effect of their presence on soil microorganism remains unknown. The objective of this study was to investigate the impacts of atrazine or Pb on the soil microbiota, soil net nitrogen mineralization, and atrazine residues over a 28-day microcosm incubation. The Shannon-Wiener diversity index, typical microbe species, and a Neighbor-joining tree of typical species from sequencing denaturing gradient gel electrophoresis (DGGE) bands were determined across periodical sampling times. The results showed that the existence of atrazine or Pb (especially high concentration) in soils reduced microbial diversity (the lowest H value is 2.23) compared to the control (H = 2.59) after a 28-day incubation. The species richness reduced little (from 17~19 species to 16~17 species) over the research time. But soil microbial community was significantly affected by the incubation time after the exposure to atrazine or Pb. The combination of atrazine and Pb had a significant inhibition effect on soil net nitrogen nitrification. Atrazine and Pb significantly stimulated soil cumulative net nitrogen mineralization and nitrification. Pb (300 and 600 mg kg(-1)) accelerated the level of atrazine dissipation. The exposure might stimulate the significant growth of the autochthonous soil degraders which may use atrazine as C source and accelerate the dissipation of atrazine in soils. PMID:25106517

  12. Soil microbial community toxic response to atrazine and its residues under atrazine and lead contamination.

    PubMed

    Chen, Qinglin; Yang, Baoshan; Wang, Hui; He, Fei; Gao, Yongchao; Scheel, Ryan A

    2015-01-01

    Intensive use of atrazine and extensive dispersal of lead (Pb) have occurred in farmland with chemical agriculture development. However, the toxicological effect of their presence on soil microorganism remains unknown. The objective of this study was to investigate the impacts of atrazine or Pb on the soil microbiota, soil net nitrogen mineralization, and atrazine residues over a 28-day microcosm incubation. The Shannon-Wiener diversity index, typical microbe species, and a Neighbor-joining tree of typical species from sequencing denaturing gradient gel electrophoresis (DGGE) bands were determined across periodical sampling times. The results showed that the existence of atrazine or Pb (especially high concentration) in soils reduced microbial diversity (the lowest H value is 2.23) compared to the control (H = 2.59) after a 28-day incubation. The species richness reduced little (from 17~19 species to 16~17 species) over the research time. But soil microbial community was significantly affected by the incubation time after the exposure to atrazine or Pb. The combination of atrazine and Pb had a significant inhibition effect on soil net nitrogen nitrification. Atrazine and Pb significantly stimulated soil cumulative net nitrogen mineralization and nitrification. Pb (300 and 600 mg kg(-1)) accelerated the level of atrazine dissipation. The exposure might stimulate the significant growth of the autochthonous soil degraders which may use atrazine as C source and accelerate the dissipation of atrazine in soils.

  13. Effects of the organic matter from swine wastewater on the adsorption and desorption of alachlor in soil.

    PubMed

    Dal Bosco, Tatiane C; Sampaio, Silvio C; Coelho, Silvia R M; Cosmann, Natássia J; Smanhotto, Adriana

    2012-01-01

    The application of swine wastewater to the soil for agricultural purposes results in the addition of total and dissolved organic matter to the soil, which may interfere with the dynamics of pesticides in the soil. The objective of this study was to evaluate the effects of the application of total and dissolved organic matter from a biodigester and a treatment lagoon of swine wastewater in the adsorption and desorption of alachlor [2-chloro-2,6-diethyl-N(methoxymethyl acetamide)]. The assay was performed by the batch equilibrium method, and the results were fitted to the Freundlich model. The curve comparison test revealed a greater adsorption of alachlor in the soil treated with swine wastewater from the biodigester. The adsorption and desorption of alachlor increased in the soils where swine wastewater was added, and hysteresis was observed in all of the treatments. PMID:22494371

  14. Effects of the organic matter from swine wastewater on the adsorption and desorption of alachlor in soil.

    PubMed

    Dal Bosco, Tatiane C; Sampaio, Silvio C; Coelho, Silvia R M; Cosmann, Natássia J; Smanhotto, Adriana

    2012-01-01

    The application of swine wastewater to the soil for agricultural purposes results in the addition of total and dissolved organic matter to the soil, which may interfere with the dynamics of pesticides in the soil. The objective of this study was to evaluate the effects of the application of total and dissolved organic matter from a biodigester and a treatment lagoon of swine wastewater in the adsorption and desorption of alachlor [2-chloro-2,6-diethyl-N(methoxymethyl acetamide)]. The assay was performed by the batch equilibrium method, and the results were fitted to the Freundlich model. The curve comparison test revealed a greater adsorption of alachlor in the soil treated with swine wastewater from the biodigester. The adsorption and desorption of alachlor increased in the soils where swine wastewater was added, and hysteresis was observed in all of the treatments.

  15. Diffuse atrazine pollution in German aquifers.

    PubMed

    Tappe, Wolfgang; Groeneweg, Joost; Jantsch, Barbara

    2002-01-01

    Until its prohibition in Germany in 1991, atrazine was the most frequently applied herbicide in maize cultivation. Moreover, it was used in orchards and vineyards and as a total herbicide on non-cultivated grounds (railways, factory grounds). Later on, atrazine was substituted mainly by terbutylazine. Terbutylazine and terbutryn are the only s-triazines presently permitted in Germany. Nevertheless, atrazine and its metabolite desethylatrazine are by far the most abundant herbicides detected in near surface groundwater. This might be due to wash-outs from the pools of atrazine and its metabolites from the soil into the groundwater or continuing illegal applications. Samples taken from maize fields in 1994 showed that 6.2% of 471 fields tested were treated with atrazine despite the prohibition of its use. Nevertheless, the overall trend is in fact a slow decrease in atrazine concentrations where it is detected in groundwater and, simultaneously often a slight increase in desethylatrazine concentrations. But this is not the case for all sampling points, and increasing concentrations in several aquifers are observed as well. Factors governing the adsorption, degradation, persistence and the possible transfer into the aquifer and the current situation concerning atrazine occurrence in German aquifers will be discussed.

  16. An analytical method for the simultaneous determination of butachlor and benoxacor in wheat and soil.

    PubMed

    Del Buono, Daniele; Scarponi, Luciano; D'Amato, Roberto

    2005-06-01

    Butachlor is a chloroacetanilide herbicide successfully employed in weeding some important crops, and benoxacor is a safening compound able to induce the enzymatic mechanism of chloroacetanilide detoxification in plants. A practical method for a simultaneous detection of butachlor and benoxacor residues in wheat and in soil is described. The procedure can be performed by GC and HPLC. They were extracted with methanol and cleaned up by solid phase extraction (SPE). The analytes were satisfactorily separated via both GC and HPLC techniques, and no interferences were observed coming from plant or soil matrixes or reagents. The limit of quantitation was found to be 5.0 ng by GC and 20.0 ng by HPLC for butachlor and 2.5 ng by GC and 15.0 ng by HPLC for benoxacor. Butachlor recovery tests ranged from 85.4% to 91.7% in wheat shoots and 84.0% to 93.2% in soil; benoxacor recovery tests ranged from 86.5% to 90.8% in wheat shoots and 85.7% to 90.7% in soil. The reproducibility and the accuracy make this method a selective and sensitive tool for routine analyses.

  17. Understanding butachlor toxicity in Aulosira fertilissima using physiological, biochemical and proteomic approaches.

    PubMed

    Kumari, Nidhi; Narayan, Om Prakash; Rai, Lal Chand

    2009-12-01

    The present study examines butachlor-induced inhibition of growth, photosynthetic pigments such as chlorophyll a, phycocyanin, allophycocyanin, phycoerythrin, photosystems I and II, whole chain electron transport, oxygen evolution, carbon fixation, ATP content, total thiol and glutathione contents of Aulosira fertilissima. For ascertaining if above mentioned changes are due to disturbance in plasma membrane integrity or proteins, fatty acid profiling and proteomics were done. Gas chromatographic (GC) analysis of fatty acid methyl esters (FAME) depicted a decrease in alpha-linolenic acid (C18:3) which appears responsible for plasma membrane instability. Enhanced lipid peroxidation and electrolyte leakage further attested the butachlor-induced cell damage. Butachlor-treated Aulosira exhibited significant and reproducible alternations in eight proteins as assessed by 2DE and LC-MS analysis of which phycocyanin alpha-chain, allophycocyanin beta-chain, C-phycocyanin alpha-subunit, ATP synthase beta-chain and FBP aldolase were associated with photosynthesis and respiration, peroxiredoxin with antioxidative defense system and GroES and NusB with protein folding and transcription termination respectively. However, a prolonged (15 d) butachlor treatment of Aulosira downregulated all the proteins except NusB. Reverse transcription PCR of the protein genes affirmed that aforesaid proteins were the gene products not artifacts. Downregulated GroES and over expressed NusB are critical proteins for cell death.

  18. Joint acute toxicity of the herbicide butachlor and three insecticides to the terrestrial earthworm, Eisenia fetida.

    PubMed

    Wang, Yanhua; Cang, Tao; Yu, Ruixian; Wu, Shenggan; Liu, Xinju; Chen, Chen; Wang, Qiang; Cai, Leiming

    2016-06-01

    The herbicide butachlor and three insecticides phoxim, chlorpyrifos, and lambda-cyhalotrhin are widely used pesticides with different modes of action. As most previous laboratory bioassays for these pesticides have been conducted solely based on acute tests with a single compound, only limited information is available on the possible combined toxicity of these common chemicals to soil organisms. In this study, we evaluated their mixture toxicity on the terrestrial earthworm, Eisenia fetida, with binary, ternary, and quaternary mixtures. Two different types of bioassays were employed in our work, including a contact filter paper toxicity test and a soil toxicity test. Mixture toxicity effects were assessed using the additive index method. For all of the tested binary mixtures (butachlor-phoxim, butachlor-chlorpyrifos, and butachlor-lambda-cyhalothrin), significant synergistic interactions were observed after 14 days in the soil toxicity assay. However, greater additive toxicity was found after 48 h in the contact toxicity bioassay. Most of the ternary and quaternary mixtures exhibited significant synergistic effects on the worms in both bioassay systems. Our findings would be helpful in assessing the ecological risk of these pesticide mixtures to soil invertebrates. The observed synergistic interactions underline the necessity to review soil quality guidelines, which are likely underestimating the adverse combined effects of these compounds.

  19. Effect of butachlor on growth and nitrogen fixation by Anabaena sphaerica.

    PubMed

    Suseela, M R

    2001-07-01

    Present study was carried out to examine the effect of Butachlor on growth and nitrogen fixation by Anabaena sphaerica. The increased concentration of the pesticide did not have any adverse effect on the alga. Rather it accelerated the algal contribution in terms of biomass and nitrogen fixation.

  20. Potential Use of Rice Field Cyanobacterium Nostoc muscorum in the Evaluation of Butachlor Induced Toxicity and their Degradation

    PubMed Central

    Anees, Sumaiya; Suhail, Shazia; Pathak, Neelam; Zeeshan, Mohd

    2014-01-01

    In the present study, butachlor (5, 10, 20, 40 and 80 ppm) induced toxicity in Nostoc muscorum and their degradation was evaluated. The dose of butachlor dependent decreased in the cell survival and growth of N. muscorum was noticed. Scanning electron microscopy revealed the adverse impact on the cell size and shapes. Low concentrations of butachlor (10 and 20 ppm) induced the over expression of a polypeptides of 31.0 K Da and 42.7 K Da, respectively which could be responsible for developing resistance in the organism up to certain level. Further, the degradation product of butachlor as a result of metabolic activities of N. muscorum, identified by GC-MS analysis includes phenols and benzene dicarboxylic acid indicating the utilization of herbicide during active growth. PMID:25097380

  1. Potential Use of Rice Field Cyanobacterium Nostoc muscorum in the Evaluation of Butachlor Induced Toxicity and their Degradation.

    PubMed

    Anees, Sumaiya; Suhail, Shazia; Pathak, Neelam; Zeeshan, Mohd

    2014-01-01

    In the present study, butachlor (5, 10, 20, 40 and 80 ppm) induced toxicity in Nostoc muscorum and their degradation was evaluated. The dose of butachlor dependent decreased in the cell survival and growth of N. muscorum was noticed. Scanning electron microscopy revealed the adverse impact on the cell size and shapes. Low concentrations of butachlor (10 and 20 ppm) induced the over expression of a polypeptides of 31.0 K Da and 42.7 K Da, respectively which could be responsible for developing resistance in the organism up to certain level. Further, the degradation product of butachlor as a result of metabolic activities of N. muscorum, identified by GC-MS analysis includes phenols and benzene dicarboxylic acid indicating the utilization of herbicide during active growth.

  2. Biodegradation of atrazine by three transgenic grasses and alfalfa expressing a modified bacterial atrazine chlorohydrolase gene.

    PubMed

    Vail, Andrew W; Wang, Ping; Uefuji, Hirotaka; Samac, Deborah A; Vance, Carroll P; Wackett, Lawrence P; Sadowsky, Michael J

    2015-06-01

    The widespread use of atrazine and other s-triazine herbicides to control weeds in agricultural production fields has impacted surface and groundwater in the United States and elsewhere. We previously reported the cloning, sequencing, and expression of six genes involved in the atrazine biodegradation pathway of Pseudomonas sp. strain ADP, which is initiated by atzA, encoding atrazine chlorohydrolase. Here we explored the use of enhanced expression of a modified bacterial atrazine chlorohydrolase, p-AtzA, in transgenic grasses (tall fescue, perennial ryegrass, and switchgrass) and the legume alfalfa for the biodegradation of atrazine. Enhanced expression of p-AtzA was obtained by using combinations of the badnavirus promoter, the maize alcohol dehydrogenase first intron, and the maize ubiquitin promoter. For alfalfa, we used the first intron of the 5'-untranslated region tobacco alcohol dehydrogenase gene and the cassava vein mosaic virus promoter. Resistance of plants to atrazine in agar-based and hydroponic growth assays was correlated with in vivo levels of gene expression and atrazine degradation. The in planta expression of p-atzA enabled transgenic tall fescue to transform atrazine into hydroxyatrazine and other metabolites. Results of our studies highlight the potential use of transgenic plants for bioremediating atrazine in the environment. PMID:25432082

  3. Contribution of hydroxylated atrazine degradation products to the total atrazine load in midwestern streams

    USGS Publications Warehouse

    Lerch, R.N.; Blanchard, P.E.; Thurman, E.M.

    1998-01-01

    The contribution of hydroxylated atrazine degradation products (HADPs) to the total atrazine load (i.e., atrazine plus stable metabolites)in streams needs to be determined in order to fully assess the impact of atrazine contamination on stream ecosystems and human health. The objectives of this study were (1) to determine the contribution of HADPs to the total atrazine load in streams of nine midwestern states and (2) to discuss the mechanisms controlling the concentrations of HADPs in streams. Stream samples were collected from 95 streams in northern Missouri at preplant and postplant of 1994 and 1995, and an additional 46 streams were sampled in eight midwestern states at postplant of 1995. Samples were analyzed for atrazine, deethylatrazine (DEA), deisopropylatrazine (DIA), and three HADPs. Overall, HADP prevalence (i.e., frequency of detection) ranged from 87 to 100% for hydroxyatrazine (HA), 0 to 58% for deethylhydroxyatrazine (DEHA), and 0% for deisopropylhydroxyatrazine (DIHA) with method detection limits of 0.04-0.10 ??g L-1. Atrazine metabolites accounted for nearly 60% of the atrazine load in northern Missouri streams at preplant, with HA the predominant metabolite present. Data presented in this study and a continuous monitoring study are used to support the hypothesis that a combination of desorption from stream sediments and dissolved-phase transport control HADP concentrations in streams.The contribution of hydroxylated atrazine degradation products (HADPs) to the total atrazine load (i.e., atrazine plus stable metabolites) in streams needs to be determined in order to fully assess the impact of atrazine contamination on stream ecosystems and human health. The objectives of this study were (1) to determine the contribution of HADPs to the total atrazine load in streams of nine midwestern states and (2) to discuss the mechanisms controlling the concentrations of HADPs in streams. Stream samples were collected from 95 streams in northern Missouri at

  4. Biodegradation of atrazine by three transgenic grasses and alfalfa expressing a modified bacterial atrazine chlorohydrolase gene.

    PubMed

    Vail, Andrew W; Wang, Ping; Uefuji, Hirotaka; Samac, Deborah A; Vance, Carroll P; Wackett, Lawrence P; Sadowsky, Michael J

    2015-06-01

    The widespread use of atrazine and other s-triazine herbicides to control weeds in agricultural production fields has impacted surface and groundwater in the United States and elsewhere. We previously reported the cloning, sequencing, and expression of six genes involved in the atrazine biodegradation pathway of Pseudomonas sp. strain ADP, which is initiated by atzA, encoding atrazine chlorohydrolase. Here we explored the use of enhanced expression of a modified bacterial atrazine chlorohydrolase, p-AtzA, in transgenic grasses (tall fescue, perennial ryegrass, and switchgrass) and the legume alfalfa for the biodegradation of atrazine. Enhanced expression of p-AtzA was obtained by using combinations of the badnavirus promoter, the maize alcohol dehydrogenase first intron, and the maize ubiquitin promoter. For alfalfa, we used the first intron of the 5'-untranslated region tobacco alcohol dehydrogenase gene and the cassava vein mosaic virus promoter. Resistance of plants to atrazine in agar-based and hydroponic growth assays was correlated with in vivo levels of gene expression and atrazine degradation. The in planta expression of p-atzA enabled transgenic tall fescue to transform atrazine into hydroxyatrazine and other metabolites. Results of our studies highlight the potential use of transgenic plants for bioremediating atrazine in the environment.

  5. Syntrophic biodegradation of butachlor by Mycobacterium sp. J7A and Sphingobium sp. J7B isolated from rice paddy soil.

    PubMed

    Kim, Nam Hyun; Kim, Dong-Uk; Kim, Ijung; Ka, Jong-Ok

    2013-07-01

    Two bacterial strains involved in syntrophic degradation of chloroacetamide herbicide butachlor were isolated from a rice paddy soil. Analysis of 16S rRNA gene sequences indicated that the two isolates were related to members of the genera Mycobacterium and Sphingobium, respectively. Thus, a pair consisted of Mycobacterium sp. J7A and Sphingobium sp. J7B could rapidly degrade butachlor (100 mg L(-1)) at 28 °C within 24 h, while each isolate alone was not able to completely degrade butachlor. The isolate Mycobacterium sp. J7A was observed to grow slightly on butachlor, possibly utilizing the alkyl side chain of butachlor as its carbon and energy source, but the isolate Sphingobium sp. J7B alone could not grow on butachlor at all. Gas chromatography-mass spectrometry on catabolic intermediates revealed that the strain J7A produced and accumulated 2-chloro-N-(2,6-diethylphenyl) acetamide (CDEPA) during growth on butachlor. This intermediate was not further degraded by strain J7A, but strain J7B was observed to be able to completely degrade and grow on it through 2,6-diethylaniline (DEA). The results showed that butachlor was completely degraded by the two isolates by syntrophic metabolism, in which strain Mycobacterium sp. J7A degraded butachlor to CDEPA, which was subsequently degraded by strain Sphingobium sp. J7B through DEA.

  6. Butachlor causes disruption of HPG and HPT axes in adult female rare minnow (Gobiocypris rarus).

    PubMed

    Zhu, Lifei; Li, Wei; Zha, Jinmiao; Wang, Miao; Yuan, Lilai; Wang, Zijian

    2014-09-25

    Butachlor is a chloroacetamide herbicide widely used in Asia, and may enter the aquatic environment through agricultural application. In this study, plasma VTG and hormone levels (E2, 11-KT, T3 and T4) were determined after the female rare minnow (Gobiocypris rarus) was exposed to butachlor at environmental relevant concentrations (0, 0.1, 1, and 10μg/L) for 40days. The mRNA levels of the HPG axis-related genes (gnrh, erα, vtg, star, lhr, 3β-hsd, cyp11a, cyp17, cyp19a and cyp19b), and the HPT axis-related genes (trα, dio1, dio2, and dio3) were quantified after 20 and 40days exposure to butachlor. For the HPG axis, the plasma 11-KT was increased at exposure concentration of 10μg/L, and VTG was significantly decreased at 1μg/L. Functional genes like gnrh and cyp19b in the brains, star, lhr, cyp11a, 3β-hsd, and cyp19a in the ovaries, and erα and vtg in livers were up-regulated. For the HPT axis, the results showed that plasma T4 levels were significantly increased, the gene expression of dio1 was up-regulated, dio2 showed no significant variation, and dio3 was down-regulated in the livers. These results indicated that butachlor may promote the accumulation of T4 in fish through inactive deiodinase type 3. The transcription of HPG axis-related genes could serve as an auto-regulation of hormone levels after exposure to butachlor. Furthermore, the activation of gnrh may play an important role as a feed-back mechanism in the regulation of hormone levels and crosstalk of endocrine axes.

  7. Persistence of the herbicide butachlor in soil after repeated applications and its effects on soil microbial functional diversity.

    PubMed

    Fang, Hua; Yu, Yun L; Wang, Xiu G; Chu, Xiao Q; Yang, Xiao E

    2009-02-01

    Effects of repeated applications of the herbicide butachlor (N-(butoxymethyl)-2-chloro -N-2',6'-dimethyl acetanilide) in soil on its persistence and soil microbial functional diversity were investigated under laboratory conditions. The degradation half-lives of butachlor at the recommended dosage in soil were calculated to be 12.5, 4.5, and 3.2 days for the first, second, and third applications, respectively. Throughout this study, no significant inhibition of the Shannon-Wiener index H' was observed. However, the Simpson index 1/D and McIntosh index U were significantly reduced (P < or = 0.05) during the initial 3 days after the first application of butachlor, and thereafter gradually recovered to a similar level to that of the control soil. A similar variation but faster recovery in 1/D and U was observed after the second and third Butachlor applications. Therefore, repeated applications of butachlor led to more rapid degradation of the herbicide, and more rapid recovery of soil microorganisms. It is concluded that repeated butachlor applications in soil had a temporary or short-term inhibitory effect on soil microbial communities.

  8. Effects of butachlor on estrogen receptor, vitellogenin and P450 aromatase gene expression in the early life stage of zebrafish.

    PubMed

    Chang, Juhua; Gui, Wenjun; Wang, Minghua; Zhu, Guonian

    2012-01-01

    Butachlor has adverse effects on fecundity and disrupts sex hormone homeostasis in adult zebrafish, but the underlying molecular mechanisms are still unclear. In the present study, zebrafish (Danio rerio) embryos were exposed to various concentrations of butachlor from 2 h post-fertilization (hpf) to 30 days post-fertilization (dpf). The transcription of genes involved estrogen receptors (ERα, ERβ1 and ERβ2), vitellogenins (VTG I and II), and cytochrome P450 aromatase (CYP19a) was analyzed by real-time quantitative PCR. The results showed that there was no significant alteration in the expression of VTGI, ERα, ERβ1, ERβ2 and CYP19a after 30 days of butachlor exposure, whereas the transcription of VTG II gene was significantly up-regulated in zebrafish exposed to 100 μg/L butachlor. It is suggested that butachlor may be a weak estrogen, and more endpoints need to be investigated to assess the effects of butachlor on the hypothalamus-pituitary-gonadal axis of zebrafish.

  9. Determination of alachlor and its sulfonic acid metabolite in water by solid-phase extraction and enzyme-linked immunosorbent assay

    USGS Publications Warehouse

    Aga, D.S.; Thurman, E.M.; Pomes, M.L.

    1994-01-01

    Solid-phase extraction (SPE) and enzyme-linked immunosorbent assay (ELISA) were combined for the trace analysis of the herbicide alachlor and its major soil metabolite, ethanesulfonic acid (ESA). The anti-alachlor antibody cross-reacted with ESA, which produced false-positive detections of alachlor in water samples by immunoassay screens. Alachlor and ESA were isolated from water by SPE on a C18 resin and eluted sequentially with ethyl acetate and methanol. Alachlor is soluble in ethyl acetate while the anionic ESA is not. Thus ESA remained adsorbed on the C18 resin and was eluted later with methanol. The combination of SPE with ELISA effectivety separated and quantified both alachlor and ESA using the same antibody for two ELISA methods. The general method may have applicability for the separation of other herbicides and their ionic metabolites. The SPE-ELISA method has a, detection limit of 0.01 ??g/L for alachlor and 0.05 ??g/L for ESA, with a precision of ?? 10%. Analyses of surface and ground water samples were confirmed by gas chromatography/mass spectrometry and high-performance liquid chromatography with photodiode-array detection. Results showed widespread occurrence of ESA in surface and ground water of the midwestern United States, with concentrations ranging from 10 ??g/L.

  10. Residual tembotrione and atrazine in carrot.

    PubMed

    Bontempo, Amanda F; Carneiro, Gabriella D P; Guimarães, Fernanda A R; Dos Reis, Marcelo R; Silva, Daniel V; Rocha, Bruno H; Souza, Matheus F; Sediyama, Tocio

    2016-07-01

    Carrot (Daucus carota L.) is a vegetable crop that is grown throughout the year across various regions of Brazil in rotation or in succession to other cultures. Herbicide residual effect has emerged as a concern, because of the possibility of carryover. Thus, the objective of this study was to evaluate the effect of tembotrione and atrazine residues - in mixture and isolated - on carrot planted in succession to corn. The experiment was designed in randomized blocks with five replications. Treatments consisted of tembotrione (50.4 g ha(-1)), tembotrione (100.8 g ha(-1)), tembotrione + atrazine (50.4 g ha(-1)+ 2 L ha(-1)), tembotrione + atrazine (100.8 g ha(-1)+ 2 L ha(-1)), and atrazine (2.00 L ha(-1)) applied eight months before carrot seeding, plus a control treatment with no herbicide application. Investigated variables were shoot dry mass, productivity, and classification of carrot roots. The presence of atrazine and tembotrione decreased dry mass in the area, and only tembotrione reduced total root productivity. Thus, there is a carryover effect to tembotrione application that reduces the dry matter accumulation of shoot and total productivity, and an atrazine + tembotrione (100.8 g ha(-1)) mixture reduces the total productivity after application of these herbicides to soil. PMID:27052932

  11. Biodegradation of atrazine by three transgenic grasses and alfalfa expressing a modified bacterial atrazine chlorohydrolase gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The widespread use of atrazine and other s-triazine herbicides to control weeds in agricultural production fields has impacted surface and ground water in the United States and elsewhere. We previously reported the cloning, sequencing, and expression of six genes involved in the atrazine biodegradat...

  12. Assessment of human exposure to atrazine through the determination of free atrazine in urine

    SciTech Connect

    Catenacci, G. ); Maroni, M. ); Cottica, D. ); Pozzoli, L.

    1990-01-01

    Studies on metabolism and excretion of atrazine in man are not available in the literature. The present study has investigated human exposure to atrazine during its industrial production by means of assessment of ambient exposure and determination of free atrazine in urine. Four workers exposed to atrazine during its manufacture and packaging in a production plant, volunteered for the study. Atrazine was determined in airborne dust of the working environment obtained by personal sampling, on skin pads according to the WHO standard method, and on the skin of the hands of the workers by means of a washing procedure. Urine was collected before, during, and after exposure. A 24 hr collection before the first workshift, all the urine voided during the monitoring period, subdivided in 8 hr fractions; and one or more 12 hr samples after the end of the exposure period were collected.

  13. Infiltration and adsorption of dissolved atrazine and atrazine metabolites in buffalograss filter strips.

    PubMed

    Krutz, L J; Senseman, S A; Dozier, M C; Hoffman, D W; Tierney, D P

    2003-01-01

    Vegetated filter strips (VFS) potentially reduce the off-site movement of herbicides from adjacent agricultural fields by increasing herbicide mass infiltrated (Minf) and mass adsorbed (Mas) compared with bare field soil. However, there are conflicting reports in the literature concerning the contribution of Mas to the VFS herbicide trapping efficiency (TE). Moreover, no study has evaluated TE among atrazine (6-chloro-N-ethyl-N'-isopropyl-[1,3,5]triazine-2,4-diamine) and atrazine metabolites. This study was conducted to compare TE, Minf, and Mas among atrazine, diaminoatrazine (DA, 6-chloro[1,3,5]triazine-2,4-diamine), deisopropylatrazine (DIA, 6-chloro-N-ethyl-[1,3,5]triazine-2,4-diamine), desethylatrazine (DEA, 6-chloro-N-isopropyl-[1,3,5]triazine-2,4-diamine), and hydroxyatrazine (HA, 6-hydroxy-N-ethyl-N'-isopropyl-[1,3,5]triazine-2,4-diamine) in a buffalograss VFS. Runoff was applied as a point source upslope of a 1- x 3-m microwatershed plot at a rate of 750 L h(-1). The point source was fortified at 0.1 microg mL(-1) atrazine, DA, DIA, DEA, and HA. After crossing the length of the plot, water samples were collected at 5-min intervals. Water samples were extracted by solid phase extraction and analyzed by high performance liquid chromatography (HPLC) photodiode array detection. During the 60-min simulation, TE was significantly greater for atrazine (22.2%) compared with atrazine metabolites (19.0%). Approximately 67 and 33% of the TE was attributed to Minf and Mas, respectively. These results demonstrate that herbicide adsorption to the VFS grass, grass thatch, and/or soil surface is an important retention mechanism, especially under saturated conditions. Values for Mas were significantly higher for atrazine compared with atrazine's metabolites. The Mas data indicate that atrazine was preferentially retained by the VFS grass, grass thatch, and/or soil surface compared with atrazine's metabolites.

  14. ATRAZINE AND REPRODUCTIVE FUNCTION: MODE AND MECHANISM OF ACTION STUDIES

    EPA Science Inventory

    Atrazine, a chlorotriazine herbicide, is used to control annual grasses and broadleaf weeds. In this review, we summarize our laboratory's work evaluating the neuroendocrine toxicity of atrazine (and related chlorotriazines) from an historic perspective. We provide the rationale ...

  15. Factors Affecting Atrazine Concentration and Quantitative Determination in Chlorinated Water

    EPA Science Inventory

    Although the herbicide atrazine has been reported to not react measurably with free chlorine during drinking water treatment, this work demonstrates that at contact times consistent with drinking water distribution system residence times, a transformation of atrazine can be obser...

  16. Boule gene expression underpins the meiotic arrest in spermatogenesis in male rainbow trout (Oncorhynchus mykiss) exposed to DEHP and butachlor.

    PubMed

    Ahmadivand, Sohrab; Farahmand, Hamid; Teimoori-Toolabi, Ladan; Mirvaghefi, Alireza; Eagderi, Soheil; Geerinckx, Tom; Shokrpoor, Sara; Rahmati-Holasoo, Hooman

    2016-01-01

    Boule, the ancestor of the DAZ (Deleted in AZoospermia) gene family, in most organisms is mainly involved in male meiosis. The present study investigates the effects of the plasticizer DEHP (50mg/kg body weight) and herbicide butachlor (0.39mg/L) on male rainbow trout (Oncorhynchus mykiss) for a 10-day period in two independent experiments. The results showed that plasma testosterone (T) concentrations were significantly lower in fish exposed to either DEHP or butachlor compared to the control fish (P<0.05). Fish showed a significantly elevated hepatosomatic index (HSI) in the butachlor treatment (P<0.05). However, no significant difference was observed in HSI values in the DEHP treatment (P>0.05). In addition, no significant differences were found in the gonadosomatic index (GSI) in both DEHP and butachlor treatments (P>0.05). Histologically, testes of male trout in the control groups were well differentiated and filled with large numbers of cystic structures containing spermatozoa. In contrast, the testes of male trout contained mostly spermatocytes with few spermatozoa in both treated group, suggesting that DEHP and butachlor may inhibit the progression of meiosis. Also, boule gene expression was significantly lower in the testes of male trout affected by DEHP and butachlor in comparison with their control groups (P<0.05), which confirmed the meiotic arrest in affected trout. Based on the results, the present study demonstrated that DEHP and butachlor can inhibit the progression of spermatogenesis in male trout, potentially by causing an arrest of meiosis, maybe due to down-regulation of boule gene expression through T and/or IGF1 via ERK1/2 signaling in T-independent pathways. In addition, these results confirmed that boule can be considered as a predictive marker to assess meiotic efficiency.

  17. Boule gene expression underpins the meiotic arrest in spermatogenesis in male rainbow trout (Oncorhynchus mykiss) exposed to DEHP and butachlor.

    PubMed

    Ahmadivand, Sohrab; Farahmand, Hamid; Teimoori-Toolabi, Ladan; Mirvaghefi, Alireza; Eagderi, Soheil; Geerinckx, Tom; Shokrpoor, Sara; Rahmati-Holasoo, Hooman

    2016-01-01

    Boule, the ancestor of the DAZ (Deleted in AZoospermia) gene family, in most organisms is mainly involved in male meiosis. The present study investigates the effects of the plasticizer DEHP (50mg/kg body weight) and herbicide butachlor (0.39mg/L) on male rainbow trout (Oncorhynchus mykiss) for a 10-day period in two independent experiments. The results showed that plasma testosterone (T) concentrations were significantly lower in fish exposed to either DEHP or butachlor compared to the control fish (P<0.05). Fish showed a significantly elevated hepatosomatic index (HSI) in the butachlor treatment (P<0.05). However, no significant difference was observed in HSI values in the DEHP treatment (P>0.05). In addition, no significant differences were found in the gonadosomatic index (GSI) in both DEHP and butachlor treatments (P>0.05). Histologically, testes of male trout in the control groups were well differentiated and filled with large numbers of cystic structures containing spermatozoa. In contrast, the testes of male trout contained mostly spermatocytes with few spermatozoa in both treated group, suggesting that DEHP and butachlor may inhibit the progression of meiosis. Also, boule gene expression was significantly lower in the testes of male trout affected by DEHP and butachlor in comparison with their control groups (P<0.05), which confirmed the meiotic arrest in affected trout. Based on the results, the present study demonstrated that DEHP and butachlor can inhibit the progression of spermatogenesis in male trout, potentially by causing an arrest of meiosis, maybe due to down-regulation of boule gene expression through T and/or IGF1 via ERK1/2 signaling in T-independent pathways. In addition, these results confirmed that boule can be considered as a predictive marker to assess meiotic efficiency. PMID:26027538

  18. Determining potential for microbial atrazine degradation in agricultural drainage ditches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Passage of agricultural runoff through vegetated drainage ditches has been shown to reduce the amount of pesticides, such as atrazine, exiting agricultural watersheds. Previous studies found that microbial communities in soil from fields treated with atrazine display enhanced rates of atrazine degr...

  19. Detecting and Confirming Accelerated Atrazine Degradation in Illinois Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical abstract: Enhanced degradation of atrazine has been documented in many parts of the world where the herbicide has been extensively used. Atrazine is widely used in corn in Illinois, but enhanced degradation in the field has not been documented. In this study, the dissipation of atrazine...

  20. The ratio of clay content to total organic carbon content is a useful parameter to predict adsorption of the herbicide butachlor in soils.

    PubMed

    Liu, Zhongzhen; He, Yan; Xu, Jianming; Huang, Panming; Jilani, Ghulam

    2008-03-01

    Thirteen soils collected from 11 provinces in eastern China were used to investigate the butachlor adsorption. The results indicated that the total organic carbon (TOC) content, clay content, amorphous Fe2O3 content, silt content, CEC, and pH had a combined effect on the butachlor sorption on soil. Combination of the data obtained from the 13 soils in the present study with other 23 soil samples reported by other researchers in the literature showed that Koc would be a poor predictive parameter for butachlor adsorption on soils with TOC content higher than 4.0% and lower than 0.2%. The soils with the ratio of clay content to TOC content (RCO) values less than 60 adsorbed butachlor mainly by the partition into soil organic matter matrix. The soils with RCO values higher than 60 apparently adsorbed butachlor by the combination of the partition into soil organic matter matrix and adsorption on clay surface.

  1. Can assessing for potential contribution of soil organic and inorganic components for butachlor sorption be improved?

    PubMed

    He, Yan; Liu, Zhongzhen; Zhang, Jian; Wang, Haizhen; Shi, Jiachun; Xu, Jianming

    2011-01-01

    Sorption of butachlor to various types of common soil components was investigated. Six pure minerals (montmorillonite [Mont], kaolinite [Kaol], Ca homoionic montmorillonite [Ca-Mont] and kaolinite [Ca-Kaol], amorphous hydrated Al and Fe oxides [AHOs-Al, AHOs-Fe]), four soil alkali-extractable pure humic acids (HAs), and the four corresponding HAs originated real unmodified and HO-treated soils were selected as the representative sorbents. Results showed that the HAs played a crucial role, and clay minerals (especially Mont) also showed an important effect in butachlor sorption. The AHOs may likely influence only in a mediator way by enhancing the availability of sorption domains of HAs. By removing 78% (on average) of the total organic carbon (TOC) from the soils with HO, the content ratio of clay to TOC (RCO) increased by an average of 367% and became >60. This change simultaneously decreased the sorption capacity of soils (40%, on average). Considering that the surface sorption domain on clay minerals may be highly exposed and more competitive after the partial removal of soil organic matter (SOM), this reaffirmed the potential contribution from clay minerals. It can thus be inferred that in the real soil where SOM and clay minerals are associated, the coating of clay minerals may have weakened the partition function of SOM or blocked some sorption domain within SOM, resulting in a decreased sorption of butachlor. Therefore, clay minerals, especially 2:1 type expanding minerals, may play a dual function vs. SOM content for the sorption of butachlor in soil.

  2. Impacts of atrazine in aquatic ecosystems.

    PubMed

    Graymore, M; Stagnitti, F; Allinson, G

    2001-06-01

    A portion of all herbicides applied to forests, croplands, road sides, and gardens are inevitably lost to water bodies either directly through runoff or indirectly by leaching through groundwater into ephemeral streams and lakes. Once in the aquatic environment, herbicides may cause stress within aquatic communities and radically alter community structure. Atrazine is one of the most effective and inexpensive herbicides in the world and is consequently used more frequently than any other herbicide. Atrazine is frequently detected in aquatic waters, and has been known to affect reproduction of aquatic flora and fauna, which in turn impacts on the community structure as a whole. This paper presents a summary of the reported direct and indirect impacts of atrazine on aquatic organisms and community structure. The information can be used for developing improved management guidelines and legislation. It is concluded that a single universal maximum limit on the atrazine application in catchments, as suggested by many regulatory authorities, does not provide adequate protection of the aquatic environment. Rather, it is advocated that flexible limits on the application of atrazine be developed in line with the potential risk of contamination to surface and subsurface water and fragility of the aquatic environment.

  3. Impacts of atrazine in aquatic ecosystems.

    PubMed

    Graymore, M; Stagnitti, F; Allinson, G

    2001-06-01

    A portion of all herbicides applied to forests, croplands, road sides, and gardens are inevitably lost to water bodies either directly through runoff or indirectly by leaching through groundwater into ephemeral streams and lakes. Once in the aquatic environment, herbicides may cause stress within aquatic communities and radically alter community structure. Atrazine is one of the most effective and inexpensive herbicides in the world and is consequently used more frequently than any other herbicide. Atrazine is frequently detected in aquatic waters, and has been known to affect reproduction of aquatic flora and fauna, which in turn impacts on the community structure as a whole. This paper presents a summary of the reported direct and indirect impacts of atrazine on aquatic organisms and community structure. The information can be used for developing improved management guidelines and legislation. It is concluded that a single universal maximum limit on the atrazine application in catchments, as suggested by many regulatory authorities, does not provide adequate protection of the aquatic environment. Rather, it is advocated that flexible limits on the application of atrazine be developed in line with the potential risk of contamination to surface and subsurface water and fragility of the aquatic environment. PMID:11485216

  4. Disposition of atrazine metabolites following uptake and degradation of atrazine in switchgrass.

    PubMed

    Albright, Vurtice C; Coats, Joel R

    2014-01-01

    Extensive use of the agricultural herbicide atrazine has led to contamination of numerous ground and surface water bodies. Research has shown that it can have a variety of negative impacts on numerous non-target organisms in the environment. Phytoremediation is one strategy that has been studied to remove atrazine contamination. This paper investigates the hypothesis that switchgrass (Panicum virgatum) can exude metabolites of atrazine after uptake and degradation, which has been suggested by prior research. Pots planted with switchgrass were treated with a 4 ppm solution of atrazine spiked with [14C]atrazine. After 4 days, switchgrass plants were transplanted to new pots with fresh sand. Four days later, the pots were sacrificed, and sand and plant samples were extracted. Plant and sand samples were analyzed for the presence of atrazine and its major metabolites. The percentage of radiotracer remaining as the parent atrazine was observed to decrease over the course of the study while the percentages of the metabolites were observed to increase. The presence of the metabolite cyanuric acid in a switchgrass phytoremediation system is reported for the first time.

  5. Fatal poisoning by butachlor and chlornitrofen ingested from a bottle marked as nitrofen.

    PubMed

    Lin, T J; Li, H P; Wong, S S; Hung, D Z; Yang, D Y

    2001-08-01

    Nitrofen has been banned in Taiwan since January 1, 1983 due to its tetrogenicity. A 78-y-o female consumed about 500 ml of herbicide, labeled as nitrofen, in a suicide attempt. Consciousness disturbance occurred immediately. After 9 h, bloody-tarry stool was noted. Hematemesis occurred 19 h later. Hepatotoxicity and nephrotoxicity also developed. Twitching of head and both upper extremities lasting 20-30 sec and up to 5 min developed on day 3. Sometimes an upward gaze with the face turned to the right or a convulsion of the right upper extremity was observed. EEG showed alpha coma, generalized slow spike-and-wave complexes, and isolated generalized sharp waves mainly in the left occipital area. On day 7, endotracheal intubation was performed due to apnea; she expired on day 9. The pesticide was found to contain butachlor and chlornitrofen. The Agricultural Committee prohibited the marketing of chlornitrofen due to its generation of tumors in animals. The combination of butachlor and chlornitrofen can result in consciousness disturbance, leucocytosis, gastrointestinal hemorrhage, rhabdomyolysis, hypocalcemia, hypoalbuminemia, elevated amylase, nephrotoxicity, hepatotoxicity, seizures and death. The cytotoxicity of butachlor may be related to the patient's death. Active components of pesticides should be checked if the clinical course of a poisoned patient is unusual to allow appropriate interventions.

  6. Comparative and combined acute toxicity of butachlor, imidacloprid and chlorpyrifos on earthworm, Eisenia fetida.

    PubMed

    Chen, Chen; Wang, Yanhua; Zhao, Xueping; Wang, Qiang; Qian, Yongzhong

    2014-04-01

    Various pesticides have become widespread contaminants of soils due to their large applications in agriculture and homes. An earthworm assay was used to assess the acute toxicity of butachlor, imidacloprid and chlorpyrifos with different modes of action. Ecotoxicities of these pesticides were compared for earthworm Eisenia fetida separately and in combination in artificial soil and contact filter paper tests. Imidacloprid was the most toxic for E. fetida with LC₅₀ (lethal concentration 50) values three orders magnitude lower than that of butachlor and chlorpyrifos in both tests. The toxicity of the mixtures was compared to that predicted by the concentration addition (CA) model. According to the CA model, the observed toxicities of all binary mixtures were less than additive. However, for all the mixtures in 14 d artificial soil test, and mixtures of butachlor plus chlorpyrifos and imidacloprid plus chlorpyrifos in 48 h contact filter paper test, the difference in toxicity was less than 30%, hence it was concluded that the mixtures conformed to CA. The combined effects of the pesticides in contact filter paper tests were not consistent with the results in artificial soil toxicity tests, which may be associated with the interaction of soil salts with the pesticides. The CA model provides estimates of mixture toxicity that did not markedly underestimate the measured toxicity, and therefore the CA model is the most suitable to use in ecological risk assessments of the pesticides.

  7. Clinico-hematological and tissue changes induced by butachlor in male Japanese quail (Coturnix japonica).

    PubMed

    Hussain, Riaz; Khan, Ahrar; Mahmood, Fazal; Rehan, Sarmad; Ali, Farah

    2014-02-01

    The present experiment was executed to determine the pathological effects induced by concurrent feeding of butachlor (chloroacetanilide herbicide) in male Japanese quail. For this purpose mature male quail about 4-5weeks of age were procured from the local market and randomly divided into six equal groups (A-F). Butachlor was mixed in corn oil and administered orally for 30days using crop tube. Four birds from each group were killed at day 10, 20 and 30 of the experiment and blood was collected with and without anticoagulant. The birds in groups (A-D) did not reveal any clinical and behavioral alterations. Clinical signs like watery droppings, dullness, ruffled feather, depression, decrease frequency of crowing, mounting with pen mates and foam production were observed. Maximum intensity of these clinical signs and behavioral alterations were observed in group F throughout the experiment. Significant lower values of erythrocytes, hematocrit percent and hemoglobin were recorded. Significantly increased numbers of erythrocytes with micronuclei, lobed and notched nuclei were observed. Histopathologically, enlarged intertubular space, fewer numbers of round spermatids, necrotic spermatids and admixture of dead spermatids were observed in testes. The results revealed significant increase in serum lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT) and urea concentrations. The results of present experimental study indicated that butachlor induces hematobiochemical and testicular changes in birds.

  8. Atrazine tolerance mechanism(s) in photoautotrophic potato cells

    SciTech Connect

    Smeda, R.J.; Hasegawa, P.M.; Weller, S.C. )

    1989-04-01

    A photoautotrophic potato cell line (variant) was isolated and is capable of sustained growth in media containing in the herbicide atrazine at concentration up to 100 x greater than the lethal concentration for the unselected (wild type) cell line (1.0 {mu}M). Fresh weight doubling times of variant cells in the presence or absence of 1.0 {mu}M atrazine were identical to wild type cells grown in the absence of atrazine. Maintenance of variant cells up to 10 passages in the absence of atrazine resulted in a reduction in the concentration of atrazine necessary to inhibit fresh weight gain by 99% (ID{sub 99}) from 100 to 80 {mu}M. Comparison of {sup 14}C-atrazine uptake indicated wild type cells accumulated up to 2.5-fold more atrazine than varient cells within 72h of exposure but no differences were detected thereafter. Electron transport of both isolated chloroplasts and intact cells were significantly inhibited in the wild type cell line by 1.0 {mu}M atrazine but unaffected in the variant cell line by atrazine concentrations up to 10 {mu}M. After 30 days in the presence of 1.0 {mu}M atrazine, wild type cells did not significantly metabolize atrazine, however, variant cells reduced atrazine concentrations to <0.05 {mu}M regardless if the initial atrazine concentration was 1.0 or 10.0 {mu}M. Both metabolism of atrazine and alterations within the chloroplast (potentially a reduction in atrazine binding affinity) appear to be important components of tolerance within variant cells.

  9. Effect of butachlor on antioxidant enzyme status and lipid peroxidation in fresh water African catfish, (Clarias gariepinus).

    PubMed

    Farombi, E O; Ajimoko, Y R; Adelowo, O A

    2008-12-01

    The present study was undertaken to evaluate the influence of butachlor, a widely used herbicide, on antioxidant enzyme system and lipid peroxidation formation in African cat fish (Clarias gariepinus). Fish were exposed to sub-lethal concentrations of butachlor 1, 2, 2.5 ppm and sacrificed 24hrs after treatment. A significant increase in malondialdehyde formation was observed in the liver, kidney, gills and heart of the fish following exposure to different concentrations of butachlor. Superoxide dismutase and catalase activities increased in the liver and kidney but decreased in the gills and heart in a concentration-dependent pattern. Glutathione level and glutathione-Stransferase activities increased (P<0.05) in the liver but decreased in the kidneys, gills and heart when fishes were exposed to the three concentrations of butachlor. The results suggest that butachlor induced oxidative stress in the various tissues of the fish particularly in the kidney and as such the organ may be subjected to severe oxidative toxicity due to depressed glutathione detoxification system.

  10. Effect of Butachlor on Antioxidant Enzyme Status and Lipid Peroxidation in Fresh Water African Catfish, (Clarias gariepinus)

    PubMed Central

    Farombi, E. O.; Ajimoko, Y. R.; Adelowo, O. A.

    2008-01-01

    The present study was undertaken to evaluate the influence of butachlor, a widely used herbicide, on antioxidant enzyme system and lipid peroxidation formation in African cat fish (Clarias gariepinus). Fish were exposed to sub-lethal concentrations of butachlor 1, 2, 2.5 ppm and sacrificed 24hrs after treatment. A significant increase in malondialdehyde formation was observed in the liver, kidney, gills and heart of the fish following exposure to different concentrations of butachlor. Superoxide dismutase and catalase activities increased in the liver and kidney but decreased in the gills and heart in a concentration-dependent pattern. Glutathione level and glutathione-S-transferase activities increased (P<0.05) in the liver but decreased in the kidneys, gills and heart when fishes were exposed to the three concentrations of butachlor. The results suggest that butachlor induced oxidative stress in the various tissues of the fish particularly in the kidney and as such the organ may be subjected to severe oxidative toxicity due to depressed glutathione detoxification system. PMID:19151438

  11. Sorption and transport of atrazine in an agricultural soil

    NASA Astrophysics Data System (ADS)

    Hakan Akyol, Nihat

    2014-05-01

    Sorption and transport of atrazine in an agricultural soil Atrazine is one of the most commonly used herbicides in large quantity worldwide. The objective of this study was to perform some batch and column experiments to examine the transport of atrazine in an agricultural soil from Turkey. Batch experiments indicated that sorption isotherm was nonlinear with a freundlich isotherm over a range of concentration (0.2-10 mg/L) examined. Column experiments showed that transport of atrazine in the soil was moderately retarded compared to non-reactive tracer (R = 2.9-4.0). The degree of retardation decreased with increasing atrazine concentration and residance time had negligable impact on degree of sorption. Flow interruption tests in the column experiments indicated that the rate-limited desorption of atrazine mainly controlled the non-ideal transport of atrazine due to the presence of organic matter fraction (0.83 %) in the soil. Sorption and desorption behavior of atrazine in such soils could have important impacts for risk assessment of atrazine-contaminated soil and should be taken into account in the regulation, management, and remediation of atrazine-contaminated sites. Keywords: Atrazine, Agricultural soil, Batch, Column, Desorption, Rate-limited desorption, Sorption, Transport.

  12. Comparative study of photocatalytic and photoelectrocatalytic properties of alachlor using different morphology TiO2/Ti photoelectrodes.

    PubMed

    Xin, Yanjun; Liu, Huiling; Han, Lei; Zhou, Yabin

    2011-09-15

    Wormhole-shaped TiO(2)/Ti (WT) and nanotube-shaped TiO(2)/Ti (TNT) photoelectrodes were prepared by anodic oxidation method. The morphology and structure were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It was found that both crystal types of WT and TNT photoelectrodes were composed of anatase and rutile TiO(2) phases; however TNT photoelectrodes had highly ordered nanostructure. The photoelectrochemical (PECH) and photoelectrocatalytic (PEC) properties of WT and TNT photoelectrodes were investigated by photocurrent transient, open-circuit potential and degradation rate of alachlor under the artificial solar light illumination. All results showed that TNT photoelectrodes prepared in NaF-Na(2)SO(4) solution have more excellent photoelectron properties than WT photoelectrodes prepared in H(2)SO(4) solution. The photocatalytic (PC) and PEC experiments of alachlor showed that PC and PEC activities of TNT photoelectrodes were superior to WT photoelectrodes. At applied bias potentials the degradation rate of alachlor at TNT photoelectrodes increased significantly to 94.5%. The higher PC and PEC performance of TNT photoelectrodes were ascribed to the long-range ordered structure and short-orientation diffusion distance of photogenerated carries.

  13. Adsorption behavior of herbicide butachlor on typical soils in China and humic acids from the soil samples.

    PubMed

    Xu, Duanping; Xu, Zhonghou; Zhu, Shuquan; Cao, Yunzhe; Wang, Yu; Du, Xiaoming; Gu, Qingbao; Li, Fasheng

    2005-05-01

    Three kinds of soils in China, krasnozem, fluvo-aquic soil, and phaeozem, as well as the humic acids (HAs) isolated from them, were used to adsorb the herbicide butachlor from water. Under the experimental conditions, the adsorption amount of butachlor on soils was positively correlated with the content of soil organic matter. HAs extracted from different kinds of soils had different adsorption capacity for the tested herbicide, which was positively correlated with their content of carbonyls. The adsorption mechanism was studied using Fourier transform infrared spectroscopy and cross-polarization with magic angle spinning 13C nuclear magnetic resonance (CP-MAS 13C NMR) techniques. It was showed that the adsorption mainly took place on the C=O, phenolic and alcoholic O-H groups of HAs. It was also confirmed that the adsorption mechanism was hydrogen bonds formation between the above groups of HAs and butachlor molecules.

  14. Development and validation of an alternative to conventional pretreatment methods for residue analysis of butachlor in water, soil, and rice.

    PubMed

    Xue, Jiaying; Jiang, Wenqing; Liu, Fengmao; Zhao, Huiyu; Wang, Suli; Peng, Wei

    2014-01-01

    A rapid and effective alternative analytical method for residues of butachlor in water, soil, and rice was established. The operating variables affecting performance of this method, including different extraction conditions and cleanup adsorbents, were evaluated. The determination of butachlor residues in soil, straw, rice hull, and husked rice was performed using GC/MS after extraction with n-hexane and cleanup with graphite carbon black. The average recoveries ranged from 81.5 to 102.7%, with RSDs of 0.6-7.7% for all of the matrixes investigated. The limits of quantitation were 0.05 mg/kg in water and rice plant, and 0.01 mg/kg in soil, straw, rice hull, and husked rice. A comparison among this proposed method, the conventional liquid-liquid extraction, the Quick, Easy, Cheap, Effective, Rugged, and Safe method, and Soxhlet extraction indicated that this method was more suitable for analyzing butachlor in rice samples. The further validation of the proposed method was carried out by Soxhlet extraction for the determination of butachlor residues in the husked rice samples, and the residue results showed there was no obvious difference obtained from these two methods. Samples from a rice field were found to contain butachlor residues below the maximum residue limits set by China (0.5 mg/kg) and Japan (0.1 mg/kg). The proposed method has a strong potential for application in routine screening and processing of large numbers of samples. This study developed a more effective alternative to the conventional analytical methods for analyzing butachlor residues in various matrixes.

  15. Single-step uncalcined N-TiO2 synthesis, characterizations and its applications on alachlor photocatalytic degradations

    NASA Astrophysics Data System (ADS)

    Suwannaruang, Totsaporn; Wantala, Kitirote

    2016-09-01

    The aims of this research were to synthesize nitrogen doped TiO2 (N-TiO2) photocatalysts produced by hydrothermal technique and to test the degradation performance of alachlor by photocatalytic process under UV irradiations in the effect of aging temperature and time in the preparation process. The characterizations of synthesized TiO2 such as specific surface area, particle size, phase structure and elements were analyzed by using the Brunauer-Emmett-Teller (BET) technique, Transmission Electron Microscopy (TEM), X-ray Diffractometer (XRD) and Energy Dispersive X-ray spectrometer (EDX), respectively. The Central Composite Design (CCD) was used to design the experiment to determine the optimal condition, main effects and their interactions by using specific surface area, percent alachlor removal and observed first-order rate constant as responses. The kinetic reactions of alachlor degradation were explained by using Langmuir-Hinshelwood expression to confirm the reaction took place on the surface of photocatalyst. The results showed that the effect of aging temperatures was significant on surface area, whereas aging time was insignificant. Additionally, the square term of aging temperature and interaction term were shown significant on the specific surface area as well. The highest specific surface area from response surface at aging temperature between 150-175 °C and aging time between 6-13 h was found in a range of 100-106 m2/g. The average particle size of TiO2 was similar to crystallite size. Therefore, it can be concluded that one particle has only one crystal. The element analysis has shown 10% of nitrogen in TiO2 structure that the energy band-gap about 2.95 eV was found. Although, the effects of aging temperature and time on percent alachlor removal and observed first-order rate constants were insignificant, both terms were significant in term of the square for alachlor photocatalytic degradation. The optimal condition of both responses was achieved at an

  16. Cyanobacterial diversity shifts induced by butachlor in selected Indian rice fields in Eastern Uttar Pradesh and Western Bihar analyzed with PCR and DGGE.

    PubMed

    Kumari, Nidhi; Narayan, Om Prakash; Rai, Lal Chand

    2012-01-01

    The present study examines the effects of 30 mg/kg butachlor on the cyanobacterial diversity of rice fields in Eastern Uttar Pradesh and Western Bihar in India. A total of 40 samples were grouped into three classes [(i) acidic, (ii) neutral, and (iii) alkaline soils], based on physicochemical and principle component analyses. Acidic soils mainly harbored Westillopsis, Trichormus, Anabaenopsis, and unicellular cyanobacteria; whereas Nostoc, Anabaena, Calothrix, Tolypothrix, and Aulosira were found in neutral and alkaline soils. Molecular characterization using 16S rRNA PCR and DGGE revealed the presence of 13 different phylotypes of cyanobacteria in these samples. Butachlor treatment of the soil samples led to the disappearance of 5 and the emergence of 2 additional phylotypes. A total of 40 DGGE bands showed significant reproducible changes upon treatment with butachlor. Phylogenetic analyses divided the phylotypes into five major clusters exhibiting interesting links with soil pH. Aulosira, Anabaena, Trichormus, and Anabaenopsis were sensitive to butachlor treatment, whereas uncultured cyanobacteria, a chroococcalean member, Westillopsis, Nostoc, Calothrix, Tolypothrix, Rivularia, Gloeotrichia, Fischerella, Leptolyngbya, and Cylindrospermum, appeared to be tolerant against butachlor at their native soil pH. Butachlor-induced inhibition of nitrogen fixation was found to be 65% (maximum) and 33% (minimum) in the soil samples of pH 9.23 and 5.20, respectively. In conclusion, low butachlor doses may prove beneficial in paddy fields having a neutral to alkaline soil pH.

  17. Environmentally friendly slow release formulations of alachlor based on clay-phosphatidylcholine.

    PubMed

    Sánchez-Verdejo, Trinidad; Undabeytia, Tomas; Nir, Shlomo; Maqueda, Celia; Morillo, Esmeralda

    2008-08-01

    A new clay-liposome complex was developed for reducing leaching of herbicides and contamination of groundwater. The liposomes were composed of the neutral and Environmental Protection Agency approved phospholipid phosphatidylcholine (PC). Adsorption of PC liposomes on the clay mineral montmorillonite could exceed the cation exchange capacity of the clay, and was well simulated by the Langmuir equation. X-ray diffraction results for 6 mM PC and 1.6 g/L clay (3 day incubation) yielded a basal spacing of 7.49 nm, which was interpreted as the formation of a supported planar bilayer on montmorillonite platelets. Fluorescence methods demonstrated structural changes which reflected adsorption of PC followed by loss of vesicle integrity as measured by the penetration of dithionite into the internal monolayer of fluorescently labeled liposomes, resulting in a decrease in fluorescence intensity to 18% of initial after 4 h. Energy transfer was demonstrated after 1 h from labeled liposomes to montmorillonite labeled by an acceptor. The neutral herbicide alachlor adsorbed on the liposome-clay complex, yielding a formulation of up to 40% active ingredient, and 1.6-fold reduction in herbicide release in comparison to the commercial formulation. Hence, the PC-montmorillonite complex can form a basis for environmentally friendly formulations of herbicides, which would yield reduced leaching.

  18. Atrazine degradation in a containerized rhizosphere system.

    PubMed

    Costa, R M; Camper, N D; Riley, M B

    2000-11-01

    The effect of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) on rhizosphere microorganisms and its fate in a containerized rhizosphere system was studied. The rhizosphere system consisted of corn grown in pot containing a defined potting mix of sand and bark with atrazine. Sterilized potting mix and a container without plants served as controls. Atrazine was extracted and analyzed via HPLC. Fluorescent pseudomonad populations increased 100-fold in the rhizposphere during a 60-day incubation period as compared to the nonvegetated control. Atrazine degradation was higher in the rhizosphere system (half-life of 7 days) compared to the nonvegetated control (half-life of greater than 45 days). The major degradation product detected in the rhizosphere system was deisopropylatrazine; other products detected included deethylatrazine, deethylhydroxyatrazine, deisopropylatrazine and hydroxyatrazine. Hydroxyatrazine was detected in the nonvegetated and sterile controls. The containerized rhizosphere system provides an experimental system to study the fate of pesticidal chemicals as well as the effects on microbial populations. PMID:11069012

  19. Nitrogen limited biobarriers remove atrazine from contaminated water: Laboratory studies

    NASA Astrophysics Data System (ADS)

    Hunter, William J.; Shaner, Dale L.

    2009-01-01

    Atrazine is one of the most frequently used herbicides. This usage coupled with its mobility and recalcitrant nature in deeper soils and aquifers makes it a frequently encountered groundwater contaminant. We formed biobarriers in sand filled columns by coating the sand with soybean oil; after which, we inoculated the barriers with a consortium of atrazine-degrading microorganisms and evaluated the ability of the barriers to remove atrazine from a simulated groundwater containing 1 mg L - 1 atrazine. The soybean oil provided a carbon rich and nitrogen poor substrate to the microbial consortium. Under these nitrogen-limiting conditions it was hypothesized that bacteria capable of using atrazine as a source of nitrogen would remove atrazine from the flowing water. Our hypothesis proved correct and the biobarriers were effective at removing atrazine when the nitrogen content of the influent water was low. Levels of atrazine in the biobarrier effluents declined with time and by the 24th week of the study no detectable atrazine was present (limit of detection < 0.005 mg L - 1 ). Larger amounts of atrazine were also removed by the biobarriers; when biobarriers were fed 16.3 mg L - 1 atrazine 97% was degraded. When nitrate (5 mg L - 1 N), an alternate source of nitrogen, was added to the influent water the atrazine removal efficiency of the barriers was reduced by almost 60%. This result supports the hypothesis that atrazine was degraded as a source of nitrogen. Poisoning of the biobarriers with mercury chloride resulted in an immediate and large increase in the amount of atrazine in the barrier effluents confirming that biological activity and not abiotic factors were responsible for most of the atrazine degradation. The presence of hydroxyatrazine in the barrier effluents indicated that dehalogenation was one of the pathways of atrazine degradation. Permeable barriers might be formed in-situ by the injection of innocuous vegetable oil emulsions into an aquifer or sandy

  20. Label-free disposable immunosensor for detection of atrazine.

    PubMed

    Belkhamssa, Najet; Justino, Celine I L; Santos, Patrícia S M; Cardoso, Susana; Lopes, Isabel; Duarte, Armando C; Rocha-Santos, Teresa; Ksibi, Mohamed

    2016-01-01

    This work reports the construction of a fast, disposable, and label-free immunosensor for the determination of atrazine. The immunosensor is based on a field effect transistor (FET) where a network of single-walled carbon nanotubes (SWCNTs) acts as the conductor channel, constituting carbon nanotubes field effect transistors (CNTFETs). Anti-atrazine antibodies were adsorbed onto the SWCNTs and subsequently the SWCNTs were protected with Tween 20 to prevent the non-specific binding of bacteria or proteins. The principle of the immunoreaction consists in the direct adsorption of atrazine specific antibodies (anti-atrazine) to SWCNTs networks. After exposed to increasing concentrations of atrazine, the CNTFETs could be used as useful label-free platforms to detect atrazine. Under the optimal conditions, a limit of detection as low as 0.001 ng mL(-1) was obtained, which is lower than that of other methods for the atrazine detection, and in a working range between 0.001 and 10 ng mL(-1). The average recoveries obtained for real water samples spiked with atrazine varied from 87.3% to 108.0%. The results show that the constructed sensors display a high sensitivity and could be useful tools for detecting pesticides like atrazine at low concentrations. They could be also applied to the determination of atrazine in environmental aqueous samples, such as seawater and riverine water. PMID:26695286

  1. Atrazine reduces reproduction in fathead minnow (Pimephales promelas)

    USGS Publications Warehouse

    Tillitt, D.E.; Papoulias, D.M.; Whyte, J.J.; Richter, C.A.

    2010-01-01

    Atrazine, the widely used herbicide, has shown to affect the hypothalamus-pituitary-gonad axis in certain vertebrate species, but few studies have examined reproductive effects of this chemical on fish. Our study was designed to evaluate a population endpoint (egg production) in conjunction with histological (e.g., gonad development) and biochemical (e.g., hormone production) phenotypes associated with atrazine exposure in fathead minnows. Adult virgin breeding groups of 1 male and 2 females were exposed to nominal concentrations of 0, 0.5, 5.0, and 50 ??g/L of atrazine in a flow-through diluter for 14 or 30 days. Total egg production was lower (19-39%) in all atrazine-exposed groups as compared to the controls. The decreases in cumulative egg production of atrazine treated fish were significant by 17-20 days of exposure. Reductions in egg production in atrazine treatment groups were most attributable to reduced numbers of spawning events with increased atrazine exposure concentrations. Gonad abnormalities were observed in both male and female fish of atrazine-exposed fish. Our results also indicate that atrazine reduces egg production through alteration of final maturation of oocytes. The reproductive effects observed in this study warrant further investigation and evaluation of the potential risks posed by atrazine, particularly feral populations of fish from streams in agricultural areas with high use of this herbicide. ?? 2010.

  2. Bioaccumulation and degradation of atrazine in several Chinese ryegrass genotypes.

    PubMed

    Sui, Ying; Yang, Hong

    2013-12-01

    Soil pollution with herbicides is a global problem. Before phytoremediation technology is developed for the plant-based clean-up of polluted soils, investigation of potential plants that can be used to accumulate and degrade herbicides is a critical step. In this study, three selected genotypes of ryegrass were comprehensively analyzed with regard to the atrazine accumulation, degradation and toxicological response. Under the conditions of soil with 0.8 mg kg(-1) atrazine, the maximum value for atrazine accumulation was 2.70 mg kg(-1) in shoots and 0.58 mg kg(-1) in roots. The residue of atrazine in soil with ryegrass cultivation was much lower than that in soil without ryegrass cultivation. Also, the content of atrazine residues in the rhizosphere was significantly lower than that in the non-rhizosphere soil. Activities of several enzymes (urease, invertase, polyphenol oxidase, acid phosphatase and alkaline phosphatase) in soil were assayed. These enzymes were depressed by atrazine but activated by ryegrass cultivation, even in the presence of atrazine. Finally, comparative studies have been conducted on the ryegrass genotypes in response to atrazine. They showed different capacities of degradation and bioaccumulation of atrazine. One of the grass cultivars Changjiang II (CJ) had better growth and higher levels of chlorophyll, but displayed less oxidative injury than two others, Abode (AB) and Jiewei (JW), under atrazine exposure. PMID:24196985

  3. Accumulation and toxicological response of atrazine in rice crops.

    PubMed

    Zhang, Jia Jun; Lu, Yi Chen; Zhang, Jin Jin; Tan, Li Rong; Yang, Hong

    2014-04-01

    Atrazine is one of the most widely used herbicides for controlling weeds and grasses. Due to its intensive use, it has become a serious contaminant in soil and water. To evaluate impact of atrazine on graminaceous crops, experiments focusing on atrazine accumulation and toxic response in rice (Oryza sativa) were carried out. Treatment with atrazine at 0.05-0.8 mg L(-1) for 6 d reduced elongation of shoot and root. Compared with a mock treatment, the elongation of shoot with atrazine was 67.1 percent of the control, whereas that of root was 79.5 percent, indicating that the shoot was more affected than the root. Atrazine was readily absorbed by rice from media. Although the quantitative absorption of atrazine was positively correlated with the external supply of the herbicide, translocation of atrazine from roots to the above-ground was reduced from 39.88±6.26 (at 0.05 mg L(-1)) to 9.25±0.27 (0.8 mg L(-1)). While accumulation of atrazine in rice plants led to toxic responses such as over-generation of hydrogen peroxide and superoxide anions, it triggered the plant defense system against the herbicide-induced oxidative stress. This was best presented by the enhanced activities of several antioxidant enzymes (e.g. superoxide dismutase, catalase and peroxidase) and expression of genes responsible for the tolerance to atrazine toxicity.

  4. Label-free disposable immunosensor for detection of atrazine.

    PubMed

    Belkhamssa, Najet; Justino, Celine I L; Santos, Patrícia S M; Cardoso, Susana; Lopes, Isabel; Duarte, Armando C; Rocha-Santos, Teresa; Ksibi, Mohamed

    2016-01-01

    This work reports the construction of a fast, disposable, and label-free immunosensor for the determination of atrazine. The immunosensor is based on a field effect transistor (FET) where a network of single-walled carbon nanotubes (SWCNTs) acts as the conductor channel, constituting carbon nanotubes field effect transistors (CNTFETs). Anti-atrazine antibodies were adsorbed onto the SWCNTs and subsequently the SWCNTs were protected with Tween 20 to prevent the non-specific binding of bacteria or proteins. The principle of the immunoreaction consists in the direct adsorption of atrazine specific antibodies (anti-atrazine) to SWCNTs networks. After exposed to increasing concentrations of atrazine, the CNTFETs could be used as useful label-free platforms to detect atrazine. Under the optimal conditions, a limit of detection as low as 0.001 ng mL(-1) was obtained, which is lower than that of other methods for the atrazine detection, and in a working range between 0.001 and 10 ng mL(-1). The average recoveries obtained for real water samples spiked with atrazine varied from 87.3% to 108.0%. The results show that the constructed sensors display a high sensitivity and could be useful tools for detecting pesticides like atrazine at low concentrations. They could be also applied to the determination of atrazine in environmental aqueous samples, such as seawater and riverine water.

  5. Impact of atrazine on chlorpyrifos toxicity in four aquatic vertebrates.

    PubMed

    Wacksman, M N; Maul, J D; Lydy, M J

    2006-11-01

    Atrazine has been shown previously to potentiate chlorpyrifos toxicity in selected invertebrates. This study examined interactions of atrazine and chlorpyrifos in four aquatic vertebrates. Organisms were exposed to binary mixtures of atrazine and chlorpyrifos during toxicity bioassays. Inhibition of cholinesterase (ChE) enzyme activity and chlorpyrifos uptake kinetics were also examined with and without atrazine exposure. Atrazine alone did not affect organisms at concentrations up to 5000 microg/L; however, the presence of atrazine at 1000 microg/L did result in a significant increase in the acute toxicity of chlorpyrifos in Xenopus laevis. Mixed results were encountered with Pimephales promelas; some bioassays showed greater than additive toxicity, while others showed an additive response. No effect of atrazine on chlorpyrifos toxicity was observed for Lepomis macrochirus and Rana clamitans. Atrazine did not affect ChE activity or chlorpyrifos uptake rates, indicating that these toxicodynamic and toxicokinetic parameters may not be related to the mechanism of atrazine potentiation of chlorpyrifos toxicity. Based on the results of this study, it does not appear that a mixture toxicity of atrazine and chlorpyrifos at environmentally relevant concentrations presents a risk to the vertebrate organisms examined in this study.

  6. Infiltration and adsorption of dissolved atrazine and atrazine metabolites in buffalograss filter strips.

    PubMed

    Krutz, L J; Senseman, S A; Dozier, M C; Hoffman, D W; Tierney, D P

    2003-01-01

    Vegetated filter strips (VFS) potentially reduce the off-site movement of herbicides from adjacent agricultural fields by increasing herbicide mass infiltrated (Minf) and mass adsorbed (Mas) compared with bare field soil. However, there are conflicting reports in the literature concerning the contribution of Mas to the VFS herbicide trapping efficiency (TE). Moreover, no study has evaluated TE among atrazine (6-chloro-N-ethyl-N'-isopropyl-[1,3,5]triazine-2,4-diamine) and atrazine metabolites. This study was conducted to compare TE, Minf, and Mas among atrazine, diaminoatrazine (DA, 6-chloro[1,3,5]triazine-2,4-diamine), deisopropylatrazine (DIA, 6-chloro-N-ethyl-[1,3,5]triazine-2,4-diamine), desethylatrazine (DEA, 6-chloro-N-isopropyl-[1,3,5]triazine-2,4-diamine), and hydroxyatrazine (HA, 6-hydroxy-N-ethyl-N'-isopropyl-[1,3,5]triazine-2,4-diamine) in a buffalograss VFS. Runoff was applied as a point source upslope of a 1- x 3-m microwatershed plot at a rate of 750 L h(-1). The point source was fortified at 0.1 microg mL(-1) atrazine, DA, DIA, DEA, and HA. After crossing the length of the plot, water samples were collected at 5-min intervals. Water samples were extracted by solid phase extraction and analyzed by high performance liquid chromatography (HPLC) photodiode array detection. During the 60-min simulation, TE was significantly greater for atrazine (22.2%) compared with atrazine metabolites (19.0%). Approximately 67 and 33% of the TE was attributed to Minf and Mas, respectively. These results demonstrate that herbicide adsorption to the VFS grass, grass thatch, and/or soil surface is an important retention mechanism, especially under saturated conditions. Values for Mas were significantly higher for atrazine compared with atrazine's metabolites. The Mas data indicate that atrazine was preferentially retained by the VFS grass, grass thatch, and/or soil surface compared with atrazine's metabolites. PMID:14674556

  7. Ammonia impacts on atrazine leaching through undisturbed soil columns

    SciTech Connect

    Liu, Z.; Clay, S.A.; Clay, D.E.

    1995-11-01

    Ammonia-based fertilizers such as anhydrous ammonia, aqua ammonia, and urea, initially increase soil pH, reducing atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) sorption and increasing atrazine desorption. Increased amounts of atrazine in soil solution may increase atrazine`s leaching potential. This laboratory study investigated atrazine leaching behavior when ammonia and atrazine applications overlap. Nondisturbed 15-cm diam. by 15-cm depth soil columns were excavated from a Brandt silty clay loam (fine silty, Pachic Udic Haploboroll) and a Ves clay loam (fine silty, mixed mesic Typic Hapludalf). Concentrated NH{sub 4}OH was applied to the soil surface at 0 or 220 kg N ha{sup -1}. Immediately after fertilizer application, 1.9 kg atrazine (spiked with ring-labeled {sup 14}C-atrazine) ha{sup -1} was applied. One day after chemical application, soil columns were leached with 5.4 L of water. The ammonia application increased leachate and surface soil pH by about 2.5 and 3.5 pH units, respectively. The amount of {sup 14}C collected in leachate from ammonia-treated columns was 60 and 30% greater for the Brandt and Ves soils, respectively, compared with untreated columns. Less {sup 14}C remained in the surface of the ammonia-treated columns than in the surface of the untreated columns. These data indicate that the interaction between ammonia-based fertilizers and atrazine must be considered when evaluating atrazine movement through soil. Applications of atrazine and ammonia-based fertilizers that increase pH should be physically separated to limit the leaching potential of atrazine. 13 refs., 3 figs., 3 tabs.

  8. Biological remediation of groundwater containing both nitrate and atrazine.

    PubMed

    Hunter, William J; Shaner, Dale L

    2010-01-01

    Due to its high usage, mobility, and recalcitrant nature, atrazine is a common groundwater contaminant. Moreover, groundwaters that are contaminated with atrazine often contain nitrate as well. Nitrate interferes with the biological degradation of atrazine and makes it more difficult to use in situ biological methods to remediate atrazine contaminated groundwater. To solve this problem we used two reactors in sequence as models of in situ biobarriers; the first was a vegetable-oil-based denitrifying biobarrier and the second an aerobic reactor that oxygenated the denitrifying reactor's effluent. The reactors were inoculated with an atrazine-degrading microbial consortium and supplied with water containing 5 mg l(-1) nitrate-N and 3 mg l(-1) atrazine. Our hypothesis was that the denitrifying barrier would remove nitrate from the flowing water and that the downstream reaction would remove atrazine. Our hypothesis proved correct; the two reactor system removed 99.9% of the atrazine during the final 30 weeks of the study. The denitrifying barrier removed approximately 98% of the nitrate and approximately 30% of the atrazine while the aerobic reactor removed approximately 70% of the initial atrazine. The system continued to work when the amount of nitrate-N in the influent water was increased to 50 mg l(-1). A mercury poisoning study blocked the degradation of atrazine indicating that biological processes were involved. An in situ denitrifying barrier coupled with an air injection system or other oxygenation process might be used to remove both nitrate and atrazine from contaminated groundwater or to protect groundwater from an atrazine spill.

  9. Derived Reference Doses (RfDs) for the environmental degradates of the herbicides alachlor and acetochlor: results of an independent expert panel deliberation.

    PubMed

    Gadagbui, Bernard; Maier, Andrew; Dourson, Michael; Parker, Ann; Willis, Alison; Christopher, John P; Hicks, Lebelle; Ramasamy, Santhini; Roberts, Stephen M

    2010-01-01

    An independent peer expert panel was convened under the auspices of the Alliance for Risk Assessment (ARA) to review toxicology data and derive oral Reference Doses (RfDs) for four environmental degradates of the acetanilide herbicides, alachlor and acetochlor. The degradates included in this evaluation were (1) alachlor tertiary-ethanesulfonic acid (ESA), (2) alachlor tertiary-oxanilic acid (OXA), (3) acetochlor ESA, and (4) acetochlor OXA. Each degradate was judged to have sufficient data for developing low to medium confidence RfD, with use of an additional uncertainty factor (UF) to cover data gaps. Body weight decreases were identified as the most sensitive treatment-related adverse effect for RfD development. A composite UF of 1000 (10 for human variability in sensitivity, 10 for interspecies differences in sensitivity, and 10 for subchronic to chronic and database deficiency combined; i.e., 10(A)x10(H)x10(S&D)) for each degradate was considered reasonable, while noting that an argument could be made for an UF of 3000 (10(A)x10(H)x30(S&D)). Based on the available data, an oral RfD of 0.2 mg/kg-day is recommended for both acetochlor ESA and acetochlor OXA and an oral RfD of 0.8 mg/kg-day is recommended for both alachlor ESA and alachlor OXA. PMID:20206657

  10. Dechlorination of Atrazine by a Rhizobium sp. Isolate

    PubMed Central

    Bouquard, C.; Ouazzani, J.; Prome, J.; Michel-Briand, Y.; Plesiat, P.

    1997-01-01

    A Rhizobium sp. strain, named PATR, was isolated from an agricultural soil and found to actively degrade the herbicide atrazine. Incubation of PATR in a basal liquid medium containing 30 mg of atrazine liter(sup-1) resulted in the rapid consumption of the herbicide and the accumulation of hydroxyatrazine as the only metabolite detected after 8 days of culture. Experiments performed with ring-labeled [(sup14)C]atrazine indicated no mineralization. The enzyme responsible for the hydroxylation of atrazine was partially purified and found to consist of four 50-kDa subunits. Its synthesis in PATR was constitutive. This new atrazine hydrolase demonstrated 92% sequence identity through a 24-amino-acid fragment with atrazine chlorohydrolase AtzA produced by Pseudomonas sp. strain ADP. PMID:16535552

  11. Toxicity studies of butachlor to the freshwater fish Channa punctata (Bloch).

    PubMed

    Tilak, K S; Veeraiah, K; Bhaskara Thathaji, P; Butchiram, M S

    2007-04-01

    The toxicity studies were conducted on the fish Channa punctata (Bloch) by employing static and continuous flow through systems, for the toxicant butachlor (technical grade+) and its commercial formulation+ (machete 50% EC). The LC50 values are 297.89 ppb and 247.46 ppb for 24 hr and 48 hr in static for technical and 636.45 and 546.09 for machete. In continuous flow through the values are 270.05, 233.52 to the technical and 567.85 and 481.49 respectively for machete. The tissues show qualitative accumulation and were quantitatively analysed by gas liquid chromatography (GLC).

  12. Bioavailability of organoclay formulations of atrazine in soil.

    PubMed

    Trigo, Carmen; Koskinen, William C; Celis, Rafael; Sadowsky, Michael J; Hermosín, María C; Cornejo, Juan

    2010-11-24

    Pesticide formulations based on organoclays have been proposed to prolong the efficacy and reduce the environmental impact of pesticides in soil. This research addressed the question of whether atrazine in organoclay-based formulations is irreversibly sorbed or is bioavailable for bacterial degradation in soil. Different cations of l-carnitine (CAR), tyramine (TYRAM), hexadimethrine (HEXADIM), phenyltrimethylammonium (PTMA), hexadecyltrimethylammonium (HDTMA), and Fe(III) were incorporated into Na-rich Wyoming montmorillonite (SWy-2) and Ca-rich Arizona montmorillonite (SAz-1) at 100% of the cation exchange capacity (CEC) of the clays as a strategy to enhance the affinity of the clay minerals for atrazine. A Buse loam soil from Becker, MN, was treated with three organoclay-based formulations of 14C-atrazine or free herbicide and incubated for 2 weeks. To determine the bioavailability of 14C-atrazine, the soil was inoculated with Pseudomonas sp. strain ADP, which rapidly mineralizes atrazine. At day 0, and after a 2 week incubation, mineralization and the amount of 14C-atrazine residues distributed between the aqueous-extractable, methanol-extractable, and bound fractions in the soil were determined to characterize the availability of nonaged and aged atrazine residues. By the end of the 2 week incubation, the microorganisms had mineralized >80% of the initial readily available (water-extractable) and >70% of the less readily available (methanol-extractable) 14C-atrazine in the soil. Bound residues increased from <4% at day 0 to ∼17% after the 2 week incubation for both the formulated and free forms of atrazine. The results of these incubation experiments show that the bioavailabilities of atrazine were similar in the case of the organoclay formulations and as free atrazine. This indicated that whereas more atrazine was sorbed and less likely to be transported in soil, when formulated as organoclay complexes, it was ultimately accessible to degrading bacteria, so

  13. Atrazine reduces reproduction in Japanese medaka (Oryzias latipes)

    USGS Publications Warehouse

    Papoulias, Diana M.; Tillitt, Donald E.; Talyknia, Melaniya G.; Whyte, Jeffrey J.; Richter, Catherine A.

    2014-01-01

    Atrazine is an effective broadleaf herbicide and the second most heavily used herbicide in the United States. Effects along the hypothalamus–pituitary–gonad axis in a number of vertebrate taxa have been demonstrated. Seasonally elevated concentrations of atrazine in surface waters may adversely affect fishes, but only a few studies have examined reproductive effects of this chemical. The present study was designed to evaluate a population endpoint (egg production) in conjunction with histological (reproductive stage, gonad pathology) and biochemical (aromatase activity, sex hormone production) phenotypes associated with atrazine exposure in Japanese medaka. Adult virgin breeding groups of one male and four females were exposed to nominal concentrations of 0, 0.5, 5.0, and 50 μg/L (0, 2.3, 23.2, 231 nM) of atrazine in a flow-through diluter for 14 or 38 days. Total egg production was lower (36–42%) in all atrazine-exposed groups as compared to the controls. The decreases in cumulative egg production of atrazine-treated fish were significant by exposure day 24. Reductions in total egg production in atrazine treatment groups were most attributable to a reduced number of eggs ovulated by females in atrazine-treated tanks. Additionally, males exposed to atrazine had a greater number of abnormal germ cells. There was no effect of atrazine on gonadosomatic index, aromatase protein, or whole body 17 β-estradiol or testosterone. Our results suggest that atrazine reduces egg production through alteration of final maturation of oocytes. The reduced egg production observed in this study was very similar to our previously reported results for fathead minnow. This study provides further information with which to evaluate atrazine's risk to fish populations.

  14. Atrazine reduces reproduction in Japanese medaka (Oryzias latipes).

    PubMed

    Papoulias, Diana M; Tillitt, Donald E; Talykina, Melaniya G; Whyte, Jeffrey J; Richter, Catherine A

    2014-09-01

    Atrazine is an effective broadleaf herbicide and the second most heavily used herbicide in the United States. Effects along the hypothalamus-pituitary-gonad axis in a number of vertebrate taxa have been demonstrated. Seasonally elevated concentrations of atrazine in surface waters may adversely affect fishes, but only a few studies have examined reproductive effects of this chemical. The present study was designed to evaluate a population endpoint (egg production) in conjunction with histological (reproductive stage, gonad pathology) and biochemical (aromatase activity, sex hormone production) phenotypes associated with atrazine exposure in Japanese medaka. Adult virgin breeding groups of one male and four females were exposed to nominal concentrations of 0, 0.5, 5.0, and 50 μg/L (0, 2.3, 23.2, 231 nM) of atrazine in a flow-through diluter for 14 or 38 days. Total egg production was lower (36-42%) in all atrazine-exposed groups as compared to the controls. The decreases in cumulative egg production of atrazine-treated fish were significant by exposure day 24. Reductions in total egg production in atrazine treatment groups were most attributable to a reduced number of eggs ovulated by females in atrazine-treated tanks. Additionally, males exposed to atrazine had a greater number of abnormal germ cells. There was no effect of atrazine on gonadosomatic index, aromatase protein, or whole body 17 β-estradiol or testosterone. Our results suggest that atrazine reduces egg production through alteration of final maturation of oocytes. The reduced egg production observed in this study was very similar to our previously reported results for fathead minnow. This study provides further information with which to evaluate atrazine's risk to fish populations.

  15. Enhanced microbial degradation of deethylatrazine in atrazine-history soils

    SciTech Connect

    Kruger, E.L.; Chaplin, J.A.; Anderson, T.A.

    1995-12-01

    Persistence and degradation of deethylatrazine, the primary metabolite of atrazine, was measured in soil with atrazine history (15 consecutive years of atrazine application) and no atrazine history (no atrazine application for 15 consecutive years). Uniformly ring-labeled {sup 14}C-deethylatrazine was applied to surface and subsurface soils for metabolism studies. After 60 d of incubation, mineralization of deethylatrazine to {sup 14}CO{sub 2} in the atrazine-history surface soil was twice that in the no-history surface soils (34% and 17% of the applied {sup 14}C, respectively). In surface soils, 25% of the applied {sup 14}C remained as deethylatrazine in the atrazine-history soil, compared with 35% in the no-history soil. Microbial plate counts indicated an increase in numbers of bacteria and fungi in soils incubated with deethylatrazine compared to control soils. Total microbial biomass of soils incubated with deethylatrazine, as determined by CO{sub 2} efflux using an infrared (IR) gas analyzer, showed no significant difference between atrazine-history, and no-history soil, but did show an increase above untreated control soils. Prior to treating soils with deethylatrazine, specific deethylatrazine degraders were quantified using a {sup 14}C-most-probable-number procedure. Deethylatrazine degraders were more numerous in atrazine-history surface soil compared to no-history surface soil. After incubation of soils with deethylatrazine, deethylatrazine degraders were more numerous in both history soils as compared to control soils. From these studies, it appears that deethylatrazine is degraded microbially to a greater extent in soils that have had long-term exposure to atrazine at field application rates compared to soils with no long-term exposure. Decreased persistence of this major metabolite of atrazine in atrazine-history soils is important in that there will be less available for movement in surface runoff and to groundwater.

  16. Atrazine and reproductive function: mode and mechanism of action studies.

    PubMed

    Cooper, Ralph L; Laws, Susan C; Das, Parikshit C; Narotsky, Michael G; Goldman, Jerome M; Lee Tyrey, E; Stoker, Tammy E

    2007-04-01

    Atrazine, a chlorotriazine herbicide, is used to control annual grasses and broadleaf weeds. In this review, we summarize our laboratory's work evaluating the neuroendocrine toxicity of atrazine (and related chlorotriazines) from an historic perspective. We provide the rationale for our work as we have endeavored to determine: 1) the underlying reproductive changes leading to the development of mammary gland tumors in the atrazine-exposed female rat; 2) the cascade of physiological events that are responsible for these changes (i.e., the mode of action for mammary tumors); 3) the potential cellular mechanisms involving adverse effects of atrazine; and 4) the range of reproductive alterations associated with this pesticide.

  17. Accurate mass analysis of ethanesulfonic acid degradates of acetochlor and alachlor using high-performance liquid chromatography and time-of-flight mass spectrometry

    USGS Publications Warehouse

    Thurman, E.M.; Ferrer, I.; Parry, R.

    2002-01-01

    Degradates of acetochlor and alachlor (ethanesulfonic acids, ESAs) were analyzed in both standards and in a groundwater sample using high-performance liquid chromatography-time-of-flight mass spectrometry with electrospray ionization. The negative pseudomolecular ion of the secondary amide of acetochlor ESA and alachlor ESA gave average masses of 256.0750??0.0049 amu and 270.0786??0.0064 amu respectively. Acetochlor and alachlor ESA gave similar masses of 314.1098??0.0061 amu and 314.1153??0.0048 amu; however, they could not be distinguished by accurate mass because they have the same empirical formula. On the other hand, they may be distinguished using positive-ion electrospray because of different fragmentation spectra, which did not occur using negative-ion electrospray.

  18. Electronic structure of herbicides: Atrazine and bromoxynil

    NASA Astrophysics Data System (ADS)

    Novak, Igor; Kovač, Branka

    2011-06-01

    The electronic structures of herbicides atrazine and bromoxynil have been investigated by UV photoelectron spectroscopy (UPS), quantum chemical calculations and comparison with X-ray diffraction, molecular docking and molecular dynamics studies. Their electronic and molecular structures are discussed in the context of their biological activity. This is the first report which correlates the molecular mechanism of biological activity of these herbicides with their experimentally determined electronic and molecular structures.

  19. Effect of crop competition and herbicides on yellow nutsedge (Cyperus esculentus L. ) and root absorption, translocation, and metabolism of alachlor and metolachlor by yellow nutsedge

    SciTech Connect

    Chamblee, R.W.

    1985-01-01

    Field studies were conducted in 1980, 1981, and 1982 to compare management programs involving different cultural practices, at-planting herbicides, and postemergence herbicides to reduce yellow nutsedge (Cyperus esculentus L.) populations, in a soybean (Glycine max (L.) Merr. Ransom)-corn (Zea mays L. Pioneer 3161 and Pioneer 3358) rotation. In laboratory studies, alachlor and metolachlor toxicity, absorption, translocation, and metabolism were investigated in different sized yellow nutsedge plants. Exposure to herbicides was restricted to plant roots. Plant sizes evaluated were 4 to 6, 10 to 15, and 18 to 22-cm tall at experiment initiation. Concentrations of greater than 0.1 ppm of both alachlor and metolachlor reduced small yellow nutsedge plant size by more than 50%. At concentrations greater than 0.2 ppm increased growth reduction was seen from metolachlor but not from alachlor. Ten to 15-cm plants exposed to 1.6 ppm of alachlor and metolachlor had plant size reductions of 48 and 62%, respectively, after 12 days. There was no difference in root absorption of /sup 14/C alachlor or /sup 14/C metolachlor from nutrient solutions. After 8 days, greater than 40, 58, and 76% of available /sup 14/C was absorbed by small, medium and large plants, respectively. After 4 and 8 days of exposure, small yellow nutsedge plants had translocated 2.6 times as much /sup 14/C metolachlor to plant shoots than /sup 14/C alachlor. Larger plants translocated the herbicides equally. Small sized plants treated with /sup 14/C metolachlor retained greater than 23% of the parent material.

  20. Hydrothermal Synthesis of FeS2 as a High-Efficiency Fenton Reagent to Degrade Alachlor via Superoxide-Mediated Fe(II)/Fe(III) Cycle.

    PubMed

    Liu, Wei; Wang, Yueyao; Ai, Zhihui; Zhang, Lizhi

    2015-12-30

    In this study, we demonstrate that hydrothermally synthesized FeS2 (syn-FeS2) is highly efficient at catalyzing the H2O2 decomposition for alachlor degradation at a wide range of initial pH (3.2-9.2). The alachlor degradation rate of syn-FeS2 heterogeneous Fenton system was almost 55 times that of its commercial pyrite (com-FeS2) counterpart at an initial pH of 6.2. Experimental results revealed that the alachlor oxidation enhancement in the syn-FeS2 Fenton system was attributed to the molecular oxygen activation induced by more surface-bound ferrous ions on syn-FeS2. The molecular oxygen activation process could generate superoxide anions to accelerate the Fe(II)/Fe(III) cycle on the syn-FeS2 surface, which favored the H2O2 decomposition to generate more hydroxyl radicals for the alachlor oxidation. It was found that the hydroxyl radicals generation rate constant of syn-FeS2 Fenton system was 71 times that of its com-FeS2 counterpart, and even 1-3 orders of magnitude larger than those of commonly used Fe-bearing heterogeneous catalysts. We detected the alachlor degradation intermediates with gas chromatography-mass spectrometry to propose tentatively a possible alachlor degradation pathway. These interesting findings could provide some new insights on the molecular oxygen activation induced by FeS2 minerals and the subsequent heterogeneous Fenton degradation of organic pollutants in the environment. PMID:26646468

  1. Influence of rhizosphere microbial ecophysiological parameters from different plant species on butachlor degradation in a riparian soil.

    PubMed

    Yang, Changming; Wang, Mengmeng; Li, Jianhua

    2012-01-01

    Biogeochemical processes in riparian zones regulate contaminant movement to receiving waters and often mitigate the impact of upland sources of contaminants on water quality. However, little research has been reported on the microbial process and degradation potential of herbicide in a riparian soil. Field sampling and incubation experiments were conducted to investigate differences in microbial parameters and butachlor degradation in the riparian soil from four plant communities in Chongming Island, China. The results suggested that the rhizosphere soil had significantly higher total organic C and water-soluble organic C relative to the nonrhizosphere soil. Differences in rhizosphere microbial community size and physiological parameters among vegetation types were significant. The rhizosphere soil from the mixed community of Phragmites australis and Acorus calamus had the highest microbial biomass and biochemical activity, followed by A. calamus, P. australis and Zizania aquatica. Microbial ATP, dehydrogenase activity (DHA), and basal soil respiration (BSR) in the rhizosphere of the mixed community of P. australis and A. calamus were 58, 72, and 62% higher, respectively, than in the pure P. australis community. Compared with the rhizosphere soil of the pure plant communities, the mixed community of P. australis and A. calamus displayed a significantly greater degradation rate of butachlor in the rhizosphere soil. Residual butachlor concentrations in rhizosphere soil of the mixed community of P. australis and A. calamus and were 48, 63, and 68% lower than three pure plant communities, respectively. Butachlor degradation rates were positively correlated to microbial ATP, DHA, and BSR, indicating that these microbial parameters may be useful in assessing butachlor degradation potential in the riparian soil.

  2. Reductive dechlorination of atrazine catalyzed by metalloporphyrins.

    PubMed

    Nelkenbaum, Elza; Dror, Ishai; Berkowitz, Brian

    2009-03-01

    Atrazine (2-chloro-4-(ethylamine)-6-(isopropylamine)-s-triazine) is a widely used herbicide which is considered a persistent groundwater contaminant. Its selective transformation mediated by cobalt or nickel porphyrins was studied in aqueous solutions at room temperature and ambient pressure. Several metalloporphyrins were examined as catalysts for the reaction and all yielded the same reaction, transforming atrazine solely to the seldomly reported form 2,4-bis(ethylamine)-6-methyl-s-triazine. The reaction involves dechlorination and migration of a methyl group to yield a symmetric product. Nickel 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin tetra(p-toluenesulfonate) (TMPyP) was activated by nanosized zero-valent iron (nZVI) while cobalt porphyrins (TMPyP, 5,10,15,20-tetrakis(4-hydroxyphenyl)-21H,23H-porphine-(TP(OH)P) and 4,4',4'',4'''-(porphine-5,10,15,20-tetrayl)tetrakis (benzenesulfonic acid)-(TBSP)) were activated by titanium(III) citrate as the electron donor. The effect of pH on atrazine transformation was demonstrated for the catalytic system of TP(OH)P-Co/Ti(III) citrate. Finally, a comparison of the reactivities of cobalt TMPyP and TP(OH)P was given and the differences discussed.

  3. Surfactant-modified bentonite clays: preparation, characterization, and atrazine removal.

    PubMed

    Dutta, Anirban; Singh, Neera

    2015-03-01

    Bentonite clay was modified using quaternary ammonium cations, viz. phenyltrimethylammonium (PTMA), hexadecyltrimethylammonium (HDTMA), trioctylmethylammonium (TOMA) [100 % of cation exchange capacity of clay], and stearylkonium (SK) [100 % (SK-I) and 250 % (SK-II) of cation exchange capacity of clay]. The organoclays were characterized using X-ray diffraction (XRD), infrared (IR) spectroscopy, and scanning electron microscopy (SEM). Atrazine adsorption on modified clays was studied using a batch method. Bentonite clay was a poor adsorbent of atrazine as 9.4 % adsorption was observed at 1 μg mL(-1) atrazine concentration. Modification of clay by PTMA cation did not improve atrazine adsorption capacity. However, atrazine adsorption in HDTMA-, TOMA-, and SK-bentonites varied between 49 and 72.4 % and data fitted well to the Freundlich adsorption isotherm (R > 0.96). Adsorption of atrazine in organoclays was nonlinear and slope (1/n) values were <1. The product of Freundlich adsorption constants, K f(1/n) in HDTMA-, TOMA-, and SK-I-bentonites was 239.2, 302.4, and 256.6, respectively, while increasing the SK cation loading in the clay (SK-II) decreased atrazine adsorption [K f(1/n) - 196.4]. Desorption of atrazine from organoclays showed hysteresis and TOMA- and SK-I-bentonites were the best organoclays to retain the adsorbed atrazine. Organoclays showed better atrazine removal from wastewater than an aqueous solution. The synthesized organoclays may find application in soil and water decontamination and as a carrier for atrazine-controlled released formulations. PMID:25273519

  4. Surfactant-modified bentonite clays: preparation, characterization, and atrazine removal.

    PubMed

    Dutta, Anirban; Singh, Neera

    2015-03-01

    Bentonite clay was modified using quaternary ammonium cations, viz. phenyltrimethylammonium (PTMA), hexadecyltrimethylammonium (HDTMA), trioctylmethylammonium (TOMA) [100 % of cation exchange capacity of clay], and stearylkonium (SK) [100 % (SK-I) and 250 % (SK-II) of cation exchange capacity of clay]. The organoclays were characterized using X-ray diffraction (XRD), infrared (IR) spectroscopy, and scanning electron microscopy (SEM). Atrazine adsorption on modified clays was studied using a batch method. Bentonite clay was a poor adsorbent of atrazine as 9.4 % adsorption was observed at 1 μg mL(-1) atrazine concentration. Modification of clay by PTMA cation did not improve atrazine adsorption capacity. However, atrazine adsorption in HDTMA-, TOMA-, and SK-bentonites varied between 49 and 72.4 % and data fitted well to the Freundlich adsorption isotherm (R > 0.96). Adsorption of atrazine in organoclays was nonlinear and slope (1/n) values were <1. The product of Freundlich adsorption constants, K f(1/n) in HDTMA-, TOMA-, and SK-I-bentonites was 239.2, 302.4, and 256.6, respectively, while increasing the SK cation loading in the clay (SK-II) decreased atrazine adsorption [K f(1/n) - 196.4]. Desorption of atrazine from organoclays showed hysteresis and TOMA- and SK-I-bentonites were the best organoclays to retain the adsorbed atrazine. Organoclays showed better atrazine removal from wastewater than an aqueous solution. The synthesized organoclays may find application in soil and water decontamination and as a carrier for atrazine-controlled released formulations.

  5. Effect of arbuscular mycorrhizal fungus (Glomus caledonium) on the accumulation and metabolism of atrazine in maize (Zea mays L.) and atrazine dissipation in soil.

    PubMed

    Huang, Honglin; Zhang, Shuzhen; Shan, Xiao-quan; Chen, Bao-Dong; Zhu, Yong-Guan; Bell, J Nigel B

    2007-03-01

    Effects of an arbuscular mycorrhizal (AM) fungus (Glomus caledonium) on accumulation and metabolism of atrazine in maize grown in soil contaminated with different concentrations of atrazine were investigated in a series of pot experiments. Roots of mycorrhizal plants accumulated more atrazine than non-mycorrhizal roots. In contrast, atrazine accumulation in shoot decreased in mycorrhizal compared with non-mycorrhizal plants. No atrazine derivatives were detected in the soil, either with or without mycorrhizal colonization. However, atrazine metabolites, deethylatrazine (DEA) and deisopropylatrazine (DIA), were detected in plant roots and the AM colonization enhanced the metabolism. After plant harvest atrazine concentrations decreased markedly in the soils compared to the initial concentrations. The decreases were the most in rhizosphere soil and then near-rhizosphere soil and the least in bulk soil. Mycorrhizal treatment enhanced atrazine dissipation in the near-rhizosphere and bulk soils irrespective of atrazine application rates.

  6. EFFECTS OF ATRAZINE ON STEROID PRODUCTION IN RAT GRANULOSA CELLS

    EPA Science Inventory

    Atrazine is one of the most widely used herbicides in the United States. Introduced in the 1950s, atrazine is a broad spectrum herbicide with current total annual use of approximately 76 million pounds of active ingredient. Frogs exhibit gonadal malformations and/or variations ...

  7. LAKE MICHIGAN MASS BALANCE PROJECT: ATRAZINE MODELLING RESULTS

    EPA Science Inventory

    The triazine herbicide, atrazine, is used worldwide to control broadleaf and grassy weeds in agricultural regions. Atrazine is extensively used for corn crops in the midwestern US, the Great Lakes region, and in the Lake Michigan basin and has been cited as an emerging pollutant ...

  8. Nitrogen Control of Atrazine Utilization in Pseudomonas sp. Strain ADP

    PubMed Central

    García-González, Vicente; Govantes, Fernando; Shaw, Liz J.; Burns, Richard G.; Santero, Eduardo

    2003-01-01

    Pseudomonas sp. strain ADP uses the herbicide atrazine as the sole nitrogen source. We have devised a simple atrazine degradation assay to determine the effect of other nitrogen sources on the atrazine degradation pathway. The atrazine degradation rate was greatly decreased in cells grown on nitrogen sources that support rapid growth of Pseudomonas sp. strain ADP compared to cells cultivated on growth-limiting nitrogen sources. The presence of atrazine in addition to the nitrogen sources did not stimulate degradation. High degradation rates obtained in the presence of ammonium plus the glutamine synthetase inhibitor MSX and also with an Nas− mutant derivative grown on nitrate suggest that nitrogen regulation operates by sensing intracellular levels of some key nitrogen-containing metabolite. Nitrate amendment in soil microcosms resulted in decreased atrazine mineralization by the wild-type strain but not by the Nas− mutant. This suggests that, although nitrogen repression of the atrazine catabolic pathway may have a strong impact on atrazine biodegradation in nitrogen-fertilized soils, the use of selected mutant variants may contribute to overcoming this limitation. PMID:14660340

  9. EFFECT OF ATRAZINE ON OVARIAN FUNCTION IN THE RAT

    EPA Science Inventory

    The effect of the chlorotriazine herbicide, atrazine, on ovarian function was studied in Long-Evans hooded (LE-hooded) and SpragucDawley (SD) rats. Atrazine was administered by gavage for 21 d to females displaying regular 4-d estrous cycles. In both sfrains, 75 mg/kg/d disrupted...

  10. Alternatives to atrazine for weed management in processing sweet corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Atrazine has been the most widely used herbicide in North American processing sweet corn for decades; however, increased restrictions in recent years have reduced or eliminated atrazine use in certain production areas. The objective of this study was to identify the best stakeholder-derived weed man...

  11. ATRAZINE EFFECTS ON EARLY PREGNANCY AND IMPLANATION IN THE RAT

    EPA Science Inventory

    Atrazine Effects on Early Pregnancy and Implantation in the Rat.
    A.M. Cummings, B.E. Rhodes*, and R.L. Cooper*.
    Reproductive Toxicology Division, NHEERL, USEPA, Research Triangle Park, NC
    Atrazine (ATR), an herbicide, can induce mammary tumors in rats. ATR can also sup...

  12. DEVELOPMENTAL TOXICITY OF ATRAZINE METABOLITES IN FISCHER 344 RATS

    EPA Science Inventory

    Previously we have shown that atrazine, a commonly used herbicide, causes full-litter resorption (FLR) in Fischer 344 rats at 50 mg/kg. In this study, we tested four atrazine metabolites for their potential to cause FLR and developmental toxicity. Desethylatrazine (DEA), desis...

  13. Response of reservoir atrazine concentrations following regulatory and management changes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since the early 1990s, atrazine concentrations in United States drinking water supplies exceeding the drinking water standard of 3 parts per billion (ppb) have been identified as a costly and major water quality concern. Atrazine levels in Columbus, Ohio tap water reached 8.74 ppb in the early 1990s...

  14. The structure of the hexameric atrazine chlorohydrolase AtzA

    PubMed Central

    Peat, T. S.; Newman, J.; Balotra, S.; Lucent, D.; Warden, A. C.; Scott, C.

    2015-01-01

    Atrazine chlorohydrolase (AtzA) was discovered and purified in the early 1990s from soil that had been exposed to the widely used herbicide atrazine. It was subsequently found that this enzyme catalyzes the first and necessary step in the breakdown of atrazine by the soil organism Pseudomonas sp. strain ADP. Although it has taken 20 years, a crystal structure of the full hexameric form of AtzA has now been obtained. AtzA is less well adapted to its physiological role (i.e. atrazine dechlorination) than the alternative metal-dependent atrazine chlorohydrolase (TrzN), with a substrate-binding pocket that is under considerable strain and for which the substrate is a poor fit. PMID:25760618

  15. Atrazine Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review

    USGS Publications Warehouse

    Eisler, R.

    1989-01-01

    The herbicide atrazine (2chloro4ethylamino6isopropylamino1,3,5triazine) is the most heavily used agricultural pesticide in North America. Domestically, more than 50 million kg are applied yearly to more than 25 million ha, primarily to control weeds in corn and sorghum crops. Atrazine residues have been detected in runoff from treated fields in lakes and streams at phytotoxic levels. Birds and mammals were comparatively resistant, with a low probability for atrazine accumulation and retention. Data are lacking on indirect effects of atrazine on wildlife granivores and insectivores. Direct effects to aquatic fauna occur at 94 micrograms/l, and higher; however, indirect effects may occur at 20 micrograms/l, and higher, partly through reduction of the food supply of herbivores, and partly through loss of macrophyte habitat. Ecological and toxicological aspects of atrazine in the environment are briefly reviewed, with special emphasis on fishery and wildlife resources.

  16. Introduction of Atrazine-Degrading Pseudomonas SP. Strain ADP to Enhance Phytoremediation of Atrazine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Atrazine (ATR) has been widely applied in the US Midwestern states. Public health and ecological concerns have been raised about contamination of surface and ground water by ATR and its chlorinated metabolites, due to their toxicity and potential carcinogenic or endocrinology effects. Phytoremediati...

  17. INTRODUCTION OF ATRAZINE-DEGRADING PSEUDOMONAS SP. STRAIN ADP TO ENHANCE PHYTOREMEDIATION OF ATRAZINE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Atrazine (ATR) has been widely applied in the US and Mid Western states. Recently, public health and ecological concerns have been raised about contamination of surface and ground water by ATR and its chlorinated metabolites, due to their toxicity and potential carcinogenic or endocrinology effects....

  18. EFFECTS OF ATRAZINE AND AN ATRAZINE METABOLITE MIXTURE ON DIFFERENTIATED MAMMARY EPITHELIAL CELL MILK PROTEIN PRODUCTION IN CULTURE

    EPA Science Inventory

    Effects of Atrazine and an Atrazine Metabolite Mixture on Differentiated Mammary Epithelial Cell Milk Protein Production in Culture

    E.P. Hines, R. Barbee, M. Blanton, M.S. Pooler, and S.E. Fenton. US EPA, ORD/NHEERL, RTD, RTP, NC, 27711, USA.

    Previous studies have ...

  19. PITUITARY AND ADRENAL HORMONE RELEASE FOLLOWING in vitro EXPOSURE TO ATRAZINE AND ITS METABOLITE DEISOPROPYL-ATRAZINE (DIA)

    EPA Science Inventory

    Atrazine (ATR) is one of the most widely used herbicides in the United States, with current total annual use of approximately 76 million pounds of active ingredient. Previous work in our laboratory has shown that ATR and its metabolite deisopropyl-atrazine (DIA) induce a dose-dep...

  20. The effects of the herbicide atrazine on freshwater snails.

    PubMed

    Gustafson, Kyle D; Belden, Jason B; Bolek, Matthew G

    2015-07-01

    Atrazine has been shown to affect freshwater snails from the subcellular to community level. However, most studies have used different snail species, methods, endpoints, and atrazine exposure concentrations, resulting in some conflicting results and limiting our understanding. The goal of this study was to address these concerns by (1) investigating the acute and chronic effects of atrazine on four species of freshwater snails (Biomphalaria glabrata, Helisoma trivolvis, Physa acuta, and Stagnicola elodes) using the same methods, endpoints, and concentrations, and (2) summarizing the current literature pertaining to the effects of atrazine on freshwater snails. We conducted a 48 h acute toxicity test with an atrazine concentration higher than what typically occurs in aquatic environments (1000 µg/L). Additionally, we exposed snails to environmentally relevant atrazine concentrations (0, 0.3, 3, and 30 µg/L) for 28 days and assessed snail survival, growth, and reproduction. We also summarized all known literature pertaining to atrazine effects on freshwater snails. The literature summary suggests snails are often affected by environmentally relevant atrazine concentrations at the subcellular and cellular levels. These effects are typically not transitive to effects on survival, growth, or reproduction at the same concentrations. Our acute exposures corroborate the general trend of no direct effect on snail populations as atrazine did not directly affect the survival of any of the four snail species. Similarly, environmentally relevant concentrations did not significantly affect the survival, growth, or reproduction of any snail species. These results indicate that, in the absence of other possible stressors, the direct effects of environmentally relevant atrazine concentrations may not be realized at the snail population level.

  1. Determination of alachlor and its metabolite 2,6-diethylaniline in microbial culture medium using online microdialysis enriched-sampling coupled to high-performance liquid chromatography.

    PubMed

    Chen, Chi-Zen; Yan, Cheing-Tong; Kumar, Ponnusamy Vinoth; Huang, Jenn-Wen; Jen, Jen-Fon

    2011-08-10

    In this study, a simple and novel microdialysis sampling technique incorporating hollow fiber liquid phase microextraction (HF-LPME) coupled online to high-performance liquid chromatography (HPLC) for the one-step sample pretreatment and direct determination of alachlor (2-chloro-2',6'-diethyl-N -(methoxymethyl)acetanilide) and its metabolite 2,6-diethylaniline (2,6-DEA) in microbial culture medium has been developed. A reversed-phase C-18 column was utilized to separate alachlor and 2,6-DEA from other species using an acetonitrile/water mixture (1:1) containing 0.1 M phosphate buffer solution at pH 7.0 as the mobile phase. Detection was carried out with a UV detector operated at 210 nm. Parameters that influenced the enrichment efficiency of online HF-LPME sampling, including the length of the hollow fiber, the perfusion solvent and its flow rate, the pH, and the salt added in sample solution, as well as chromatographic conditions were thoroughly optimized. Under optimal conditions, excellent enrichment efficiency was achieved by the microdialysis of a sample solution (pH 7.0) using hexane as perfusate at the flow rate of 4 μL/min. Detection limits were 72 and 14 ng/mL for alachlor and 2,6-DEA, respectively. The enrichment factors were 403 and 386 (RSD < 5%) for alachlor and 2,6-DEA, respectively, when extraction was performed by using a 40 cm regenerated cellulose hollow fiber and hexane as perfusion solvent at the flow rate of 0.1 μL/min. The proposed method provides a sensitive, flexible, fast, and eco-friendly procedure to enrich and determine alachlor and its metabolite (2,6-DEA) in microbial culture medium. PMID:21707080

  2. Effects of atrazine on periphyton under grazing pressure.

    PubMed

    Muñoz, I; Real, M; Guasch, H; Navarro, E; Sabater, S

    2001-11-12

    An experiment was carried out using indoor experimental channels to assess the long-term effect (18 days) of herbivores (Physella acuta, Gastropoda) on periphyton communities exposed to low levels of atrazine (14 microg l(-1)). We hypothesized that herbivorism modifies the response of periphyton to atrazine. Carbon incorporation, chlorophyll-a content, biovolume and algal taxonomic composition in the channels that contained atrazine were not significantly different from the control channels (not receiving atrazine). In channels with grazers and atrazine, there was a significant reduction of carbon incorporation and algal density. In this treatment, physiognomic forms and algal composition were significantly different from the others. The biomass of grazers (measured as change in dry mass) was not significantly affected by the addition of atrazine. Grazers maintained low levels of periphyton biomass, enhancing algal cell exposition to toxicant and inhibiting any adaptation of the algae to the toxic exposure. The increase in atrazine toxicity with grazing not only affected the metabolism, but also the structure of the algal community, which suggests that effects were not transient but permanent. PMID:11595312

  3. Effects of atrazine on cercarial longevity, activity, and infectivity.

    PubMed

    Koprivnikar, Janet; Forbes, Mark R; Baker, Robert L

    2006-04-01

    Susceptibility of free-living infective stages of parasites to contaminants is relatively understudied compared with independent effects on measures of host health or immunity, but may be important in affecting prevalence and intensity of parasite infections. We investigated whether atrazine, an herbicide commonly used in North America, affected the cercariae of 4 different species of digenetic trematodes, and found that effects of atrazine concentration on mortality and activity of cercariae varied among species. Mortality of Echinostoma trivolvis increased in a 200 microg/L atrazine solution, and a species of Alaria showed both decreased activity and increased mortality. We also examined whether the ability of E. trivolvis to infect the second intermediate host, larval amphibians, was compromised by atrazine exposure. Longevity and prevalence of E. trivolvis cercariae was affected at 200 microg/L atrazine, whereas intensity of infection in Rana clamitans tadpoles was reduced at both 20 microg/L and 200 microg/L atrazine. Our results indicate that the viability of cercariae of some species is compromised by exposure to atrazine, emphasizing the importance of considering the influence of contaminants on free-living stages of parasites in addressing how environmental degradation may relate to host parasitism.

  4. Effects of the agrochemicals butachlor, pretilachlor and isoprothiolane on rat liver xenobiotic-metabolizing enzymes.

    PubMed

    Ishizuka, M; Iwata, H; Kazusaka, A; Hatakeyama, S; Fujita, S

    1998-11-01

    1. The herbicides butachlor (2-chloro-2',6',diethyl-N-[buthoxymethyl] acetanilide) and pretilachlor (2-chloro-2',6'-diethyl-N-[2-propoxyethyl] acetanilide) are widely used in Asia, South America, Europe and Africa. Isoprothiolane (diisopropyl-1,3-dithiolan-2-ylidenemalonate) is used as a fungicide and an insecticide in rice paddies. We administered these agrochemicals to the male rat and examined their effects on cytochrome P450 (P450), glutathione S-transferase (GST), UDP-glucuronosyltransferase (UDPGT), and NAD(P)H-quinone oxidoreductase 1 (NQO1)-related metabolism in the liver. 2. Administration of isoprothiolane, butachlor or pretilachlor to rat induced hepatic P4502B subfamily-dependent enzyme activities (pentoxyresorufin O-depentylation and testosterone 16 beta-hydroxylation) up to 271-413% of control, which coincided with the increase in expression levels of the P4502B apoprotein. 3. Activities of GST toward 1-chloro-2,4-nitrobenzene and 3,4-dichloronitrobenzene were slightly induced (127-133% of control) in the liver of the rat treated with these pesticides. On the other hand, marked elevations of UDPGT activities toward p-nitrophenol (164-281% of control) were observed. NQO1-related metabolism (menadione reductase activity) was also induced (123-176% of control) in the liver of rat treated with these agrochemicals. 4. These results indicate that some of the agrochemicals currently in use are capable of inducing phase I and II xenobiotic-metabolizing enzyme activities in an isozyme selective manner. The induction of these activities may disrupt normal physiologic functions related to these enzymes in exposed animals.

  5. Atrazine dissipation in s-Triazine-adapted and Non-adapted soil from Coloroado and Mississippi: Implications of enhanced degradation on atrazine fate and transport parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modelers and regulatory agencies typically use default atrazine half-life values of 60 to 120 d to predict the herbicide’s transport; however, if atrazine persistence is reduced in soils exhibiting enhanced degradation, but modelers continue to use historic atrazine persistence estimates, then accur...

  6. Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis)

    PubMed Central

    Hayes, Tyrone B.; Khoury, Vicky; Narayan, Anne; Nazir, Mariam; Park, Andrew; Brown, Travis; Adame, Lillian; Chan, Elton; Buchholz, Daniel; Stueve, Theresa; Gallipeau, Sherrie

    2010-01-01

    The herbicide atrazine is one of the most commonly applied pesticides in the world. As a result, atrazine is the most commonly detected pesticide contaminant of ground, surface, and drinking water. Atrazine is also a potent endocrine disruptor that is active at low, ecologically relevant concentrations. Previous studies showed that atrazine adversely affects amphibian larval development. The present study demonstrates the reproductive consequences of atrazine exposure in adult amphibians. Atrazine-exposed males were both demasculinized (chemically castrated) and completely feminized as adults. Ten percent of the exposed genetic males developed into functional females that copulated with unexposed males and produced viable eggs. Atrazine-exposed males suffered from depressed testosterone, decreased breeding gland size, demasculinized/feminized laryngeal development, suppressed mating behavior, reduced spermatogenesis, and decreased fertility. These data are consistent with effects of atrazine observed in other vertebrate classes. The present findings exemplify the role that atrazine and other endocrine-disrupting pesticides likely play in global amphibian declines. PMID:20194757

  7. Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis).

    PubMed

    Hayes, Tyrone B; Khoury, Vicky; Narayan, Anne; Nazir, Mariam; Park, Andrew; Brown, Travis; Adame, Lillian; Chan, Elton; Buchholz, Daniel; Stueve, Theresa; Gallipeau, Sherrie

    2010-03-01

    The herbicide atrazine is one of the most commonly applied pesticides in the world. As a result, atrazine is the most commonly detected pesticide contaminant of ground, surface, and drinking water. Atrazine is also a potent endocrine disruptor that is active at low, ecologically relevant concentrations. Previous studies showed that atrazine adversely affects amphibian larval development. The present study demonstrates the reproductive consequences of atrazine exposure in adult amphibians. Atrazine-exposed males were both demasculinized (chemically castrated) and completely feminized as adults. Ten percent of the exposed genetic males developed into functional females that copulated with unexposed males and produced viable eggs. Atrazine-exposed males suffered from depressed testosterone, decreased breeding gland size, demasculinized/feminized laryngeal development, suppressed mating behavior, reduced spermatogenesis, and decreased fertility. These data are consistent with effects of atrazine observed in other vertebrate classes. The present findings exemplify the role that atrazine and other endocrine-disrupting pesticides likely play in global amphibian declines. PMID:20194757

  8. Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis).

    PubMed

    Hayes, Tyrone B; Khoury, Vicky; Narayan, Anne; Nazir, Mariam; Park, Andrew; Brown, Travis; Adame, Lillian; Chan, Elton; Buchholz, Daniel; Stueve, Theresa; Gallipeau, Sherrie

    2010-03-01

    The herbicide atrazine is one of the most commonly applied pesticides in the world. As a result, atrazine is the most commonly detected pesticide contaminant of ground, surface, and drinking water. Atrazine is also a potent endocrine disruptor that is active at low, ecologically relevant concentrations. Previous studies showed that atrazine adversely affects amphibian larval development. The present study demonstrates the reproductive consequences of atrazine exposure in adult amphibians. Atrazine-exposed males were both demasculinized (chemically castrated) and completely feminized as adults. Ten percent of the exposed genetic males developed into functional females that copulated with unexposed males and produced viable eggs. Atrazine-exposed males suffered from depressed testosterone, decreased breeding gland size, demasculinized/feminized laryngeal development, suppressed mating behavior, reduced spermatogenesis, and decreased fertility. These data are consistent with effects of atrazine observed in other vertebrate classes. The present findings exemplify the role that atrazine and other endocrine-disrupting pesticides likely play in global amphibian declines.

  9. Relative mobilities of atrazine, atrazine degradates, metolachlor, and simazine in five soils from Iowa

    SciTech Connect

    Coats, J.R.; Kruger, E.L.; Beilei Zhu

    1995-12-31

    The relative mobilities of atrazine, deethylatrazine, deisopropylatrazine, didealkylatrazine, hydroxyatrazine, ammeline, metolachlor and simazine were determined in soils from five locations in Iowa by soil thin-layer chromatography (TLC). Surface (0 to 30 cm) and subsurface (65 to 90 cm) soils taken from Ames, Treynor, Fruitland, Nashua, and Chariton were used to make soil TLC plates. Uniformly ring-labeled {sup 14}C chemicals were spotted on plates which were then developed by ascending chromatography using water as the solvent. Preliminary results from Ames, Treynor, and Fruitland soils indicate four groups based on relative mobilities. Deethylatrazine was the most mobile compound studied. The intermediate mobility group included atrazine, didealkylatrazine, and deisopropylatrazine. The less mobile group included metolachlor and simazine, however, metolachlor was, in some soils, in the intermediate mobility group. The immobile group included ammeline and hydroxyatrazine. Additional results from Nashua and Chariton soils, as well as correlations of mobility with soil characteristics will also be presented.

  10. Effects of (Anti) Androgenic Endocrine Disruptors (DEHP and Butachlor) on Immunoglobulin M (IgM) and Leukocytes Counts of Male Rainbow Trout (Oncorhynchus mykiss).

    PubMed

    Ahmadivand, Sohrab; Farahmand, Hamid; Mirvaghefi, Alireza; Eagderi, Soheil; Zargar, Ashkan

    2015-06-01

    The effect of two anti-androgenic endocrine disrupting compounds, i.e. the plasticizer di (2-ethylhexyl) phthalate (DEHP) and herbicide butachlor, were evaluated for their effects on immunoglobulin M (IgM) and leukocytes in male rainbow trout. Also, plasma testosterone (T) concentration was measured to confirm their anti-androgenic effects. In the first experiment, trout were treated with 50 mg/kg (body weight) DEHP intraperitoneally, and in the second one, fish were exposed to 0.39 mg/L butachlor for 10 days. The results showed that T concentrations and white blood cells were significantly lower in fish exposed to either DEHP or butachlor compared to control fish (p < 0.05). Fish showed significantly elevated neutrophil levels and decreased lymphocyte levels in the butachlor (p < 0.05); however, no significant difference was observed in lymphocyte and neutrophils values in the DEHP treatment (p > 0.05). In addition, no significant differences were found in IgM, eosinophil and monocyte parameters in either DEHP or butachlor treatments (p > 0.05). These results confirmed that leukocytes counts can be considered as a novel marker of immunotoxicity triggered by (anti) androgenic endocrine disruptors.

  11. Effects of (Anti) Androgenic Endocrine Disruptors (DEHP and Butachlor) on Immunoglobulin M (IgM) and Leukocytes Counts of Male Rainbow Trout (Oncorhynchus mykiss).

    PubMed

    Ahmadivand, Sohrab; Farahmand, Hamid; Mirvaghefi, Alireza; Eagderi, Soheil; Zargar, Ashkan

    2015-06-01

    The effect of two anti-androgenic endocrine disrupting compounds, i.e. the plasticizer di (2-ethylhexyl) phthalate (DEHP) and herbicide butachlor, were evaluated for their effects on immunoglobulin M (IgM) and leukocytes in male rainbow trout. Also, plasma testosterone (T) concentration was measured to confirm their anti-androgenic effects. In the first experiment, trout were treated with 50 mg/kg (body weight) DEHP intraperitoneally, and in the second one, fish were exposed to 0.39 mg/L butachlor for 10 days. The results showed that T concentrations and white blood cells were significantly lower in fish exposed to either DEHP or butachlor compared to control fish (p < 0.05). Fish showed significantly elevated neutrophil levels and decreased lymphocyte levels in the butachlor (p < 0.05); however, no significant difference was observed in lymphocyte and neutrophils values in the DEHP treatment (p > 0.05). In addition, no significant differences were found in IgM, eosinophil and monocyte parameters in either DEHP or butachlor treatments (p > 0.05). These results confirmed that leukocytes counts can be considered as a novel marker of immunotoxicity triggered by (anti) androgenic endocrine disruptors. PMID:25708297

  12. Linking Watershed Atrazine and PCB Loads to Lake Michigan

    EPA Science Inventory

    An introduction, overview, and results of mathematical modeling in Lake Michigan. The presentation focuses on model mass balances and forecasts for atrazine and PCBs. The mass balance provides an overview of the sources, interactions, movement, behavior, and fate of contaminant...

  13. Atrazine degradation in a small stream in Iowa

    USGS Publications Warehouse

    Kolpin, D.W.; Kalkhoff, S.J.

    1993-01-01

    A study was conducted during 1990 through an 11.2-km reach of Roberts Creek in northeastern Iowa to determine the fate of atrazine in a surface water environment Water samples were collected at ~1-month intervals from April through November during stable low to medium flow conditions and analyzed for atrazine and two of its initial biotic degradation products, desethylatrazine and deisopropylatrazine. Samples were collected on the basis of a Lagrangian model of streamflow in order to sample the same parcel of water as it moved downstream. Atrazine concentrations substantially decreased (roughly 25-60%) between water entering and exiting the study reach during four of the seven sampling periods. During these same four sampling periods, the concentrations of the two biotic atrazine degradation products were constant or decreasing downstream, suggesting an abiotic degradation process.

  14. Atrazine disrupts the hypothalamic control of pituitary-ovarian function.

    PubMed

    Cooper, R L; Stoker, T E; Tyrey, L; Goldman, J M; McElroy, W K

    2000-02-01

    The chloro-S-triazine herbicides (i.e., atrazine, simazine, cyanazine) constitute the largest group of herbicides sold in the United States. Despite their extensive usage, relatively little is known about the possible human-health effects and mechanism(s) of action of these compounds. Previous studies in our laboratory have shown that the chlorotriazines disrupt the hormonal control of ovarian cycles. Results from these studies led us to hypothesize that these herbicides disrupt endocrine function primarily through their action on the central nervous system. To evaluate this hypothesis, we examined the estrogen-induced surges of luteinizing hormone (LH) and prolactin in ovariectomized Sprague-Dawley (SD) and Long-Evans hooded (LE) rats treated with atrazine (50-300 mg/kg/day, by gavage) for 1, 3, or 21 days. One dose of atrazine (300 mg/kg) suppressed the LH and prolactin surge in ovariectomized LE, but not SD female rats. Atrazine (300 mg/kg) administered to intact LE females on the day of vaginal proestrus was without effect on ovulation but did induce a pseudopregnancy in 7 of 9 females. Three daily doses of atrazine suppressed the estrogen-induced LH and prolactin surges in ovariectomized LE females in a dose-dependent manner, but this same treatment was without effect on serum LH and prolactin in SD females. The estrogen-induced surges of both pituitary hormones were suppressed by atrazine (75-300 mg/kg/day) in a dose-dependent manner in females of both strains evaluated after 21 days of treatment. Three experiments were then performed to determine whether the brain, pituitary, or both organs were the target sites for the chlorotriazines. These included examination of the ability of (1) the pituitary lactotrophs to secrete prolactin, using hypophyosectomized females bearing pituitary autotransplants (ectopic pituitaries); (2) the synthetic gonadotropin-releasing hormone (GnRH) to induce LH secretion in females treated with high concentrations of atrazine for 3

  15. Atrazine increases the sodium absorption in frog (Rana esculenta) skin.

    PubMed

    Cassano, Giuseppe; Bellantuono, Vito; Ardizzone, Concetta; Lippe, Claudio

    2006-02-01

    The presence of atrazine in agricultural sites has been linked to the decline in amphibian populations. The efforts of the scientific community generally are directed toward investigating the long-term effect of atrazine on complex functions (reproduction or respiration), but in the present study, we investigated the short-term effect on the short-circuit current (I(sc)), a quantitative measure of the ion transport operated by frog (Rana esculenta) skin. Treatment with 5 microM atrazine (1.08 mg/L) does not affect the transepithelial outfluxes of [14C]mannitol or [14C]urea; therefore, atrazine does not damage the barrier properties of frog skin. Atrazine causes a dose-dependent increase in the short-circuit current, with a minimum of 4.64 +/- 0.76 microA/cm2 (11.05% +/- 1.22%) and a maximum of 12.7 +/- 0.7 microA/cm2 (35% +/- 2.4%) measured at 10 nM and 5 microM, respectively. An increase in Isc also is caused by 5 microM ametryne, prometryn, simazine, terbuthylazine, or terbutryn (other atrazine derivatives). In particular, atrazine increases the transepithelial 22Na+ influx without affecting the outflux. Finally, stimulation of Isc by atrazine is suppressed by SQ 22536, H89, U73122, 2-aminoethoxydiphenyl borate, and W7 (blockers of adenylate cyclase, protein kinase A, phospholipase C, intracellular Ca2+ increase, and calmodulin, respectively), whereas indomethacin and calphostin C (inhibitors of cyclooxygenase and protein kinase C, respectively) have no effect.

  16. Treatability of atrazine in a simulated DEPHANOX process.

    PubMed

    Sponza, Delia T; Atalay, Hulya

    2009-02-15

    In this study a simulated DEPHANOX process was used, including anaerobic/anoxic and oxic phases. An upflow anaerobic sludge blanket reactor (UASB), an anoxic sludge blanket reactor (UANSB) and a completely stirred tank reactor (CSTR) were used, sequentially. The atrazine, chemical oxygen demand (COD) removal efficiencies, methane and nitrogen (N2) gas productions and volatile fatty acid (VFA) concentrations were monitored to assess the stability and the performance of anaerobic/anoxic and oxic reactors. The produced intermetabolites were Diaminochloroatrazine(DACT), Desethylatrazine(DEA), Deisopropylatrazine(DIA) urea, ammonia, aromatic amines, Cl(-1) and NO3-N. For maximum atrazine and COD removal efficiencies (86% and 82%, respectively) the optimum atrazine concentrations were between 30-80 mg L(-1). The methane gas percentage varied between 40 and 68% while no N2 production was observed in the anaerobic UASB reactor; 6-10 mg L(-1) of urea, 4-21 mg L(-1) of ammonia, 8-10 mg L(-1) of aromatic amine and 4-6 mg L of Cl(-1) were detected during anaerobic atrazine degradation. 25-45% N2 gas production was observed in the anoxic reactor while the methane gas production was 1-5%. In the aerobic phase COD and atrazine were removed with removal efficiencies of 98% and 99% for initial atrazine concentrations of 0.3 mg L(-1) and 2.5 mg L(-1), respectively.

  17. Mineralization of atrazine in agricultural soil: inhibition by nitrogen.

    PubMed

    Guillén Garcés, Rosa Angélica; Hansen, Anne M; van Afferden, Manfred

    2007-05-01

    Microbial mineralization of atrazine was characterized in soils and liquid media in the presence of nitrogen fertilizer concentrations representing typical field applications. The mineralization of atrazine in soils varied between 6 and 99% after 18 d of incubation. Half-lives of between 0.99 and more than 18 d were obtained. Mineralization kinetics and degree are related by a reciprocal trend to concentrations of available nitrogen in the soil. In liquid media, half-lives were calculated as 0.12 d in the absence of fertilizer nitrogen and as 79 d in the presence of 1,000 mg/L of KNO3-N. Only 20% of atrazine was mineralized after 18 d of incubation in the presence of this concentration of KNO3-N, whereas greater than 90% mineralization occurred after 2 d of incubation in liquid medium without KNO3-N. The results demonstrate that the mineralization of atrazine is inhibited even at fertilizer nitrogen levels lower than typical field applications. Inhibition in soil is lower than that in liquid medium, possibly because of the higher complexity of the soil system. This may explain why atrazine that infiltrates to the groundwater is persistent. The microbial consortium of the soils was characterized, and seven species were identified. The degrading capacity of these species suggests that only three species are involved in the degradation of atrazine.

  18. Assessing atrazine persistence in soil following a severe drought

    SciTech Connect

    Leavitt, R.A.; Kells, J.J.; Bunkelmann, J.R.; Hollingworth, R.M. )

    1991-01-01

    Much of the corn production region in the US, including Michigan, experienced a severe drought during the 1988 growing season. The very little rainfall coupled with temperatures above normal created extremely dry soil conditions during the period when soil moisture is usually adequate in Michigan raised concern about herbicide carryover. Atrazine (2-chloro-40(ethylamino)-6-(isopropylamino)-s-triazine) is the most widely used herbicide with potential to persist in sufficient quantity to injure sensitive rotational crops. Atrazine is degraded in soil by both chemical hydrolysis and microbial breakdown with these processes occurring much more rapidly under conditions of adequate soil moisture and relatively warm temperature. It is generally accepted that the risk of atrazine carryover is greater following a year of low rainfall, since microbial activity is favored by adequate soil moisture. The 1988 drought created a critical need for an assessment of atrazine concentration in soil to advise producers on crop management options related to atrazine sensitive crops. The objectives of this study were to assess: (1) atrazine residue levels in Michigan soils following the 1988 drought, and (2) the suitability of the immunoassay technique over a wide variety of soils.

  19. Impact of atrazine on aneuploidy in pacific oysters, Crassostrea gigas.

    PubMed

    Bouilly, Karine; Leitão, Alexandra; McCombie, Helen; Lapègue, Sylvie

    2003-01-01

    Aneuploidy has previously been described and studied in the Pacific oyster, Crassostrea gigas, and has been shown to be negatively correlated with growth. The present study investigated the effect of atrazine on the level of aneuploidy in this species. Crassostrea gigas adults and juveniles were subjected to different concentrations of atrazine representing a peak value found in a polluted environment (46.5 nM) and a value 10 times higher (465 nM). Although atrazine did not show any effect on the oyster mortality, significant differences in aneuploidy level were observed between the different treatments (9% for the control, 16% for 46.5 nM and 20% for 465 nM atrazine). Moreover, the same levels of aneuploidy were observed at adult and juvenile stages. This is the first reported evidence for an environmental effect on aneuploidy in C. gigas. These results will be useful for the oyster aquaculture industry and management of resources. The lowest atrazine level in the current study represents realistic potential exposure, and the results suggest that studies should be made on other aquatic species at risk of exposure to atrazine in the wild. This widely used compound may be an important factor causing damage to genetic material.

  20. Investigating the in situ degradation of atrazine in groundwater.

    PubMed

    Pearson, Robert; Godley, Andrew; Cartmell, Elise

    2006-04-01

    This study focused on whether or not atrazine could be degraded by indigenous groundwater bacteria as part of an in situ remediation approach. Groundwater was taken from an unconfined middle upper chalk site where concentrations of atrazine and nitrate were typically in the ranges 0.02-0.2 microg litre-1 and 11.6-25.1 mg NO3-N litre-1 respectively. Sacrificial batch studies were performed using this groundwater spiked with atrazine at a concentration of 10 microg litre-1 in conjunction with a minimal mineral salts liquid (Glu-MMSL) medium which contained glucose as the sole carbon source. Treatments comprised either the Glu-MMSL groundwater cultured bacteria or Pseudomonas sp. strain ADP. Results from sacrificial batches indicated the occurrence of bacterial growth and denitrification as monitored by optical density (absorbance at 600 nm) and NO3-N content. Analysis of atrazine content by solid phase extraction coupled with high-performance liquid chromatography showed no degradation of atrazine over a period of 103 days in either treatment. These results indicated that no acclimatised bacterial community featuring positive degraders to the herbicide atrazine had become established within this chalk aquifer in response to the trace levels encountered.

  1. Modeling the environmental fate of atrazine

    SciTech Connect

    Devillers, J.; Bintein, S.; Domine, D.

    1996-10-01

    Modeling the environmental distribution of organic pollutants from their physicochemical properties is essential for hazard assessment. For this purpose, biosphere is generally divided into a given number of compartments (e.g., air, water, soil) and the physical, chemical, and biological processes involved in the environmental fate of pollutants are defined in terms of mathematical equations. Models are then computed so that an easy and rapid handling is offered. Based on this strategy, CHEMFRANCE, a regional fugacity level III model allowing to calculate the environmental distribution of organic chemicals in France or any user-defined region is well suited for rapid screening analyses. In this study, CHEMFRANCE was used for modeling the environmental fate of atrazine. The simulations were compared with field and laboratory results recorded in Europe and North-America.

  2. Behavior of butachlor and pyrazosulfuron-ethyl in paddy water using micro paddy lysimeters under different temperature conditions in spring and summer.

    PubMed

    Ok, Junghun; Doan, Nguyen Hai; Watanabe, Hirozumi; Thuyet, Dang Quoc; Boulange, Julien

    2012-08-01

    The behavior of butachlor and pyrazosulfuron-ethyl in paddy water was investigated using micro paddy lysimeters with prescribed hydrological conditions under ambient temperature in spring and summer for simulating two rice crop seasons. Although they were not significantly different, the dissipation of both herbicides in paddy water in the summer experiment was faster than in the spring experiment. The half-lives (DT(50)) in paddy water for spring and summer experiments were 3.2 and 2.5 days for butachlor, and 3.1 and 1.6 days for pyrazosulfuron-ethyl, respectively.

  3. Behavior of butachlor and pyrazosulfuron-ethyl in paddy water using micro paddy lysimeters under different temperature conditions in spring and summer.

    PubMed

    Ok, Junghun; Doan, Nguyen Hai; Watanabe, Hirozumi; Thuyet, Dang Quoc; Boulange, Julien

    2012-08-01

    The behavior of butachlor and pyrazosulfuron-ethyl in paddy water was investigated using micro paddy lysimeters with prescribed hydrological conditions under ambient temperature in spring and summer for simulating two rice crop seasons. Although they were not significantly different, the dissipation of both herbicides in paddy water in the summer experiment was faster than in the spring experiment. The half-lives (DT(50)) in paddy water for spring and summer experiments were 3.2 and 2.5 days for butachlor, and 3.1 and 1.6 days for pyrazosulfuron-ethyl, respectively. PMID:22696099

  4. DISTRIBUTION OF ATRAZINE IN PC12 CELLS AND MODULATION OF CATECHOLAMINE SYNTHESIS

    EPA Science Inventory

    Previously, we reported that atrazine disrupts ovarian function by altering hypothalamic catecholamine (CA) concentrations and the consequent regulation of pituitary LH release and prolactin secretion in the young female rat. We also showed that atrazine directly interacts with t...

  5. GESTATIONAL ATRAZINE EXPOSURE IN THE RAT: EFFECTS ON MAMMARY GLAND DEVELOPMENT AND FUNCTION IN MULTIPLE GENERATIONS

    EPA Science Inventory

    The chlorotriazine herbicides currently represent the most heavily used of all agricultural pesticides, with atrazine being the most common of these chemicals. Rodent toxicology studies indicate that atrazine can disrupt endocrine function and among its effects is an increased in...

  6. Evaluation of atrazine degradation applied to different energy systems.

    PubMed

    Moreira, Ailton J; Pinheiro, Bianca S; Araújo, André F; Freschi, Gian P G

    2016-09-01

    Atrazine is an herbicide widely used in crops and has drawn attention due to potential pollution present in soil, sediment, water, and food. Since conventional methods are not potentially efficient to persistent degradation of organic compounds, new technology has been developed to remove them, especially practices utilizing advanced oxidation processes (AOPs). This work aims to evaluate the use of different energies (ultraviolet (UV), microwaves (MW), and radiations (MW-UV)) to the herbicide atrazine through the process of photo-oxidation. These systems found degradation rates of around 12 % (UV), 28 % (MW), and 83 % (MW-UV), respectively, with time intervals of 120 s. After the photolytic processes, the samples were analyzed at a wavelength scanning the range of 190 to 300 nm, where the spectral analysis of the signal was used to evaluate the degradation of atrazine and the appearance of some other peaks (degradation products). The spectrum evaluation resulting from photolytic processes gave rise to a new signal which was confirmed by chromatography. This spectrum indicated the possible pathway of atrazine degradation by the process of photolytic MW-UV, generating atrazine-2-hydroxy, atrazine-desethyl-2-hidroxy, and atrazine-desisopropyl-2-hydroxy. The process indicated that in all situations, chloride was present in the analytic structure and was substituted by a hydroxyl group, which lowered the toxicity of the compound through the photolytic process MW-UV. Chromatographic analysis ascertained these preliminary assessments using spectrophotometry. It was also significantly observed that the process can be optimized by adjusting the pH of the solution, which was evident by an improvement of 10 % in the rate of degradation when subjected to a pH solution equal to 8.37. PMID:27289373

  7. Toxicity and physical properties of atrazine and its degradation products: A literature survey

    SciTech Connect

    Pugh, K.C.

    1994-10-01

    The Tennessee Valley Authority`s Environmental Research Center has been developing a means of detoxifying atrazine waste waters using TiO{sub 2} photocatalysis. The toxicity and physical properties of atrazine and its degradation products will probably be required information in obtaining permits from the United States Environmental Protection Agency for the demonstration of any photocatalytic treatment of atrazine waste waters. The following report is a literature survey of the toxicological and physical properties of atrazine and its degradation products.

  8. Manganese dioxide as a catalyst for oxygen-independent atrazine dealkylation

    SciTech Connect

    Wang, D.; Shin, J.J.; Cheney, M.; Sposito, G.; Spiro, T.

    1999-09-16

    The herbicide atrazine is widely distributed in the environment, and its reactivity with soil minerals is an important issue. We have studied atrazine degradation on the surface of synthetic {delta}-MnO{sub 2}(birnessite) using UV resonance raman spectroscopy and gas chromatography. The products are mainly mono and didealkyl atrazine. Atrazine disappearance is rapid {tau}1/2 {approx} 5 h at 30C and independent of whether O{sub 2} is present or not.

  9. Waste Foundry Sand Soil Amendment to Reduce Atrazine Loading to Surface Runoff

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of experiments was conducted to evaluate the potential for surface applied foundry sand (FS) waste material to reduce atrazine in runoff water from fields having atrazine-based weed management. In the first experiment, the ability of several FSs to remove atrazine from the water column was ...

  10. Clastogenicity of atrazine assessed with the Allium cepa test.

    PubMed

    Bolle, Paola; Mastrangelo, Sabina; Tucci, Paolo; Evandri, Maria G

    2004-01-01

    Atrazine is classified as a restricted use pesticide and it is currently included in an international revision program for re-evaluating the human and ecological (non-human populations) health risks associated with its release into the environment. The present study was undertaken to add new data on the genotoxic potential of atrazine using the Allium cepa chromosome aberration test. The test concentrations were based on the Maximum Contaminant Levels in water intended for human consumption set by European and US regulations. Atrazine produced a concentration-related increase in the number of total somatic chromosome aberrations, although this increase was statistically significant (p<0.05) only at the highest test concentration (5 microg/L). Analysis of the categories of structural chromosome damage indicated that breaks were the predominant lesion induced; the percent of cells per bulb with breaks also increased in a concentration-related manner, and the increase was statistically significant at the two highest test concentrations (1 and 5 microg/L) (p<0.05). The Allium cepa plant assay detected the clastogenicity of atrazine at concentrations that are likely to be encountered in water, a common site of atrazine contamination.

  11. Whole Genome Sequence Analysis of an Alachlor and Endosulfan Degrading Micrococcus sp. strain 2385 Isolated from Ochlockonee River, Florida.

    PubMed

    Pathak, Ashish; Chauhan, Ashvini; Ewida, Ayman Y I; Stothard, Paul

    2016-01-01

    We recently isolated Micrococcus sp. strain 2385 from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides- alachlor [(2-chloro-2`,6`-diethylphenyl-N (methoxymethyl)acetanilide)] and endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(e)di-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain 2385, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of Micrococcus sp. strain 2385 consisted of 1,460,461,440 bases which assembled into 175 contigs with an N50 contig length of 50,109 bases and a coverage of 600x. The genome size of this strain was estimated at 2,431,226 base pairs with a G+C content of 72.8 and a total number of 2,268 putative genes. RAST annotated a total of 340 subsystems in the genome of strain 2385 along with the presence of 2,177 coding sequences. A genome wide survey indicated that that strain 2385 harbors a plethora of genes to degrade other pollutants including caprolactam, PAHs (such as naphthalene), styrene, toluene and several chloroaromatic compounds.

  12. Whole Genome Sequence Analysis of an Alachlor and Endosulfan Degrading Micrococcus sp. strain 2385 Isolated from Ochlockonee River, Florida.

    PubMed

    Pathak, Ashish; Chauhan, Ashvini; Ewida, Ayman Y I; Stothard, Paul

    2016-01-01

    We recently isolated Micrococcus sp. strain 2385 from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides- alachlor [(2-chloro-2`,6`-diethylphenyl-N (methoxymethyl)acetanilide)] and endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(e)di-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain 2385, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of Micrococcus sp. strain 2385 consisted of 1,460,461,440 bases which assembled into 175 contigs with an N50 contig length of 50,109 bases and a coverage of 600x. The genome size of this strain was estimated at 2,431,226 base pairs with a G+C content of 72.8 and a total number of 2,268 putative genes. RAST annotated a total of 340 subsystems in the genome of strain 2385 along with the presence of 2,177 coding sequences. A genome wide survey indicated that that strain 2385 harbors a plethora of genes to degrade other pollutants including caprolactam, PAHs (such as naphthalene), styrene, toluene and several chloroaromatic compounds. PMID:27672405

  13. Whole Genome Sequence Analysis of an Alachlor and Endosulfan Degrading Micrococcus sp. strain 2385 Isolated from Ochlockonee River, Florida

    PubMed Central

    Pathak, Ashish; Chauhan, Ashvini; Ewida, Ayman Y.I.; Stothard, Paul

    2016-01-01

    We recently isolated Micrococcus sp. strain 2385 from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides- alachlor [(2-chloro-2`,6`-diethylphenyl-N (methoxymethyl)acetanilide)] and endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(e)di-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain 2385, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of Micrococcus sp. strain 2385 consisted of 1,460,461,440 bases which assembled into 175 contigs with an N50 contig length of 50,109 bases and a coverage of 600x. The genome size of this strain was estimated at 2,431,226 base pairs with a G+C content of 72.8 and a total number of 2,268 putative genes. RAST annotated a total of 340 subsystems in the genome of strain 2385 along with the presence of 2,177 coding sequences. A genome wide survey indicated that that strain 2385 harbors a plethora of genes to degrade other pollutants including caprolactam, PAHs (such as naphthalene), styrene, toluene and several chloroaromatic compounds.

  14. Whole Genome Sequence Analysis of an Alachlor and Endosulfan Degrading Micrococcus sp. strain 2385 Isolated from Ochlockonee River, Florida

    PubMed Central

    Pathak, Ashish; Chauhan, Ashvini; Ewida, Ayman Y.I.; Stothard, Paul

    2016-01-01

    We recently isolated Micrococcus sp. strain 2385 from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides- alachlor [(2-chloro-2`,6`-diethylphenyl-N (methoxymethyl)acetanilide)] and endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(e)di-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain 2385, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of Micrococcus sp. strain 2385 consisted of 1,460,461,440 bases which assembled into 175 contigs with an N50 contig length of 50,109 bases and a coverage of 600x. The genome size of this strain was estimated at 2,431,226 base pairs with a G+C content of 72.8 and a total number of 2,268 putative genes. RAST annotated a total of 340 subsystems in the genome of strain 2385 along with the presence of 2,177 coding sequences. A genome wide survey indicated that that strain 2385 harbors a plethora of genes to degrade other pollutants including caprolactam, PAHs (such as naphthalene), styrene, toluene and several chloroaromatic compounds. PMID:27672405

  15. Tea bag filter paper as a novel protective membrane for micro-solid phase extraction of butachlor in aqueous samples.

    PubMed

    Pelden, Tshering; Thammaknet, Chongdee; Thavarungkul, Panote; Kanatharana, Proespichaya

    2014-01-01

    An innovative, cost-effective, simple, and environmental friendly tea bag filter paper protected micro-solid phase extraction (μ-SPE) technique was developed for the first time with the aim to miniaturize and minimize the use of organic solvents for the extraction and determination of butachlor in aqueous samples. The μ-SPE device was produced by packing 3.0 mg of an easily synthesized new sorbent, hydroxyl-functionalized polypyrrole (OH-PPY), inside a small tea bag filter paper sachet (1.0 cm × 0.5 cm) that served as a protective envelope. Both the extraction and desorption procedures were facilitated by sonication. Due to the high porosity and the fast water absorption of the tea bag filter paper, the analyte could easily diffuse through and enhance the interaction with the sorbent. Under the optimized conditions for the GC-ECD and the μ-SPE, the limit of detection (S/N ≥ 3) was 2.0 μg L(-1) while the limit of quantitation (S/N ≥ 10) was 10.0 μg L(-1). The recoveries of the butachlor spiked at 0.050, 0.10, and 0.50 μg mL(-1) ranged from 77.9 ± 3.0 to 112.5 ± 2.9%. The proposed method was successfully applied for the determination of butachlor in water samples from paddy cultivation sites. The levels found were from non-detectable to 24.71 ± 0.37 μg L(-1).

  16. Identity and pathogenesis of stomach tumors in Sprague-Dawley rats associated with the dietary administration of butachlor.

    PubMed

    Hard, G C; Iatropoulos, M J; Thake, D C; Wheeler, D; Tatematsu, M; Hagiwara, A; Williams, G M; Wilson, A G

    1995-05-01

    Macroscopic stomach tumors induced in Sprague-Dawley rats during two chronic bioassays with the acetanilide herbicide butachlor at a dietary concentration of 3000 ppm, were evaluated histologically and immunohistochemically in order to determine their identity and pathogenesis. The tumors, which occurred primarily in female rats, were a heterogeneous series, including a few consisting wholly or partly of classic solid or anaplastic epithelium, but with the majority containing diffusely distributed primitive neoplastic cells. The latter had either the general appearance of undifferentiated epithelium or presented a more "mesenchyme-like" pattern where the cells were epithelioid, blastema-like, neuroendocrine-like or sarcoma-like with fascicular disposition. Gastric glandular profiles were also present, usually located near the periphery of the tumors, but in some cases extending into the diffuse tumor tissue. Most of the tumors displayed variable immunohistochemical reactivity for cytokeratin, vimentin and neuron-specific enolase but were negative for muscle-specific actin or desmin except in the stromal tracts. Detailed examination of all available gastric tissue revealed the presence of additional microscopic neoplasms and precursor hyperplastic lesions. All of these were typical gastric neuroendocrine cell lesions (gastric carcinoids) originating in the fundic mucosa but occasionally invading submucosally, and consisting of epithelial cells in organized clusters, rosettes or primitive tubules. The enterochromaffin-like (ECL) nature of these microscopic neoplasms and precursor lesions was substantiated by strong immunohistochemical reactivity for cytokeratin, neuron-specific enolase and chromogranin A, and a negative reaction for vimentin. One microscopic tumor showed a transition from differentiated neuroendocrine type in the fundic mucosa to a dispersed "mesenchyme-like" pattern in the submucosal extension. An additional finding in the butachlor-treated male and

  17. Kinetics and spectroscopic observations of atrazine dealkylation on manganese oxides

    SciTech Connect

    Malengreau, N.; Sposito, G.; Cheney, M.A.; Crowley, D.E.

    1997-12-31

    Abiotic transformations of organic pollutants are often neglected in remediation scenarios but nonetheless can contribute significantly to detoxification. Mn oxide minerals are capable of degrading organic pollutants adsorbed to their surfaces by both redox and proton-promoted mechanisms. Concurrently with calorimetric, gas-pressure, chromatographic, and ESR methods, we used ICP, DRS, DRIFT, and FTIR spectroscopies to investigate atrazine degradation on three Mn oxides. We found that N-dealkylation can occur abiotically, leading to the formation of deethylatrazine and deisopropylatrazine. The Mn extractability after degradation of atrazine was highly dependent on the Mn oxide. Extractable Mn increased with time for cryptomelane, was constant for pyrolusite, and remained very low for birnessite. The extractable Mn is Mn(II). UV signatures of atrazine by-products were different from one another and were used to trace degradation products at the Mn oxide surface. Mechanistic interpretation of the in situ reaction kinetics and thermodynamics will be discussed.

  18. Abiotic dealkylation and hydrolysis of atrazine by birnessite.

    PubMed

    Shin, Jin Y; Cheney, Marcos A

    2005-06-01

    Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) and its degradation products are important contaminants of world water systems and have effects on aquatic life. These effects are modulated by the degradation of atrazine, which depends, in part, on its reactivity with soil minerals. We have studied the degradation reaction of atrazine on synthetic birnessite (delta-MnO2) in the aqueous phase using a batch reactor and a developed high-performance liquid chromatography method. The reaction was studied in the absence of light at 25 degrees C and between pH 2.3 to pH 8.3. The reaction rates increased with decreasing pH and increasing delta-MnO2 loading, and they did not follow simple first-order kinetics. The major products are hydroxylated and mono- and didealkylatrazine. Ammeline and cyanuric acid also were detected. The half-life (t 1/2) for the degradation of atrazine was approximately 16.8 d and independent of oxygen. Manganese(II) evolution was a minor product. The mechanism of dealkylation involved proton transfer to Mn(IV)-stabilized oxo and imido bonds, with no net oxidation and reduction. Oxidation was a secondary reaction. The proposed abiotic pathway for the transformation of atrazine on delta-MnO2 was identical to the reported biotic pathway. Thus, delta-MnO2, a common soil component, facilitated the efficient N-dealkylation and hydrolysis of the herbicide atrazine at 25 degrees C, possibly via a nonoxidative mechanisms. The N-dealkylation has been attributed strictly to a biological process in soils.

  19. Dielectric barrier discharge plasma induced degradation of aqueous atrazine.

    PubMed

    Feng, Jingwei; Jiang, Lin; Zhu, Dan; Su, Kuizu; Zhao, Dayong; Zhang, Jibiao; Zheng, Zheng

    2016-05-01

    Degradation of herbicide atrazine in aqueous solution was investigated using a plate type dielectric barrier discharge (DBD) plasma reactor. DBD plasma was generated at the gas-liquid interface of the formed water film. At discharge time of 14 min, atrazine was degradated effectively with a degradation rate of 99 % at the discharge power of 200 W. The experimental data fitted well with first-order kinetics and the energy efficiency for 90 % degradation of atrazine (G value) was calculated, obtaining a rate constant of 0.35 min(-1) and a G value of 1.27 × 10(-10) mol J(-1) (98.76 mg kW(-1) h(-1)) at a discharge power of 200 W, respectively. The addition of Fe(2+) increased the rate constant and G value dramatically, and a significant decrease of the rate constant and G value was observed with the addition of radical scavengers (tert-butyl alcohol, isopropyl alcohol, or Na2CO3). The generated aqueous O3 and H2O2 were determined, which promoted the degradation of herbicide atrazine. Dechlorination was observed and the experimentally detected Cl(-) was 1.52 mg L(-1) at a discharge time of 14 min. The degradation intermediates of atrazine were detected by means of liquid chromatography-mass spectrometry; dechlorination, hydroxylation, dealkylation, and alkyl oxidation processes were involved in the degradation pathways of atrazine. PMID:26832879

  20. Chemical modification and degradation of atrazine in Medicago sativa through multiple pathways.

    PubMed

    Zhang, Jing Jing; Lu, Yi Chen; Yang, Hong

    2014-10-01

    Atrazine is a member of the triazine herbicide family intensively used to control weeds for crop production. In this study, atrazine residues and its degraded products in alfalfa (Medicago sativa) were characterized using UPLC-TOF-MS/MS. Most of atrazine absorbed in plants was found as chemically modified derivatives like deisopropylated atrazine (DIA), dehydrogenated atrazine (DHA), or methylated atrazine (MEA), and some atrazine derivatives were conjugated through different functional groups such as sugar, glutathione, and amino acids. Interestingly, the specific conjugates DHA+hGSH (homoglutathione) and MEA-HCl+hGSH in alfalfa were detected. These results suggest that atrazine in alfalfa can be degraded through different pathways. The increased activities of glycosyltransferase and glutathione S-transferase were determined to support the atrazine degradation models. The outcome of the work uncovered the detailed mechanism for the residual atrazine accumulation and degradation in alfalfa and will help to evaluate whether the crop is suitable to be cultivated in the atrazine-polluted soil.

  1. Estimation of the Potential for Atrazine Transport in a Silt Loam Soil

    USGS Publications Warehouse

    Eckhardt, D.A.V.; Wagenet, R.J.

    1996-01-01

    The transport potential of the herbicide atrazine (2-chloro-4-ethyl-6-isopropyl-s-triazine) through a 1-meter-thick root zone of corn (Zea mays L.) in a silty-loam soil in Kansas was estimated for a 22-year period (1972-93) using the one-dimensional water-flow and solute-transport model LEACHM. Results demonstrate that, for this soil, atrazine transport is directly related to the amount and timing of rain that follows spring applications of atrazine. Two other critical transport factors were important in wet years - [1] variability in atrazine application rate, and [2] atrazine degradation rates below the root zone. Results demonstrate that the coincidence of heavy rain soon after atrazine application can cause herbicide to move below the rooting zone into depths at which biodegradation rates are assumed to be low but are often unknown. Atrazine that reaches below the rooting zone and persists in the underlying soil can subsequently be transported into ground water as soil water drains, typically after the growing season. A frequency analysis of atrazine concentrations in subsurface drainage, combined with field data, demonstrates the relative importance of critical transport factors and confirms a need for definitive estimates of atrazine-degradation rates below the root zone. The analysis indicates that periodic leaching of atrazine can be expected for this soil when rainfall that exceeds 20 cm/mo coincides with atrazine presence in soil.

  2. Effects of atrazine on Ochrobactrum anthropi membrane fatty acids.

    PubMed Central

    Laura, D; De Socio, G; Frassanito, R; Rotilio, D

    1996-01-01

    Ochrobactrum anthropi is a gram-negative bacillus recognized as a human opportunist pathogen isolated in clinical specimens and not of clinical significance. We report a new aspect of this bacterium, that it has been isolated from activated sludge. In fact, it is able to grow on atrazine (2-chloro-4-ethylamino-6-isopropyl-amine-s-triazine) by utilizing it as the only source of carbon. Our results show that atrazine (0.03 g/liter) causes a dramatical increase in the degree of saturation of membrane fatty acids. Analysis and identification of bacterial fatty acids were performed by gas chromatography and gas chromatography-mass spectrometry techniques. PMID:8779602

  3. Behavioral responses to atrazine and diuron in goldfish.

    PubMed

    Saglio, P; Trijasse, S

    1998-10-01

    Experiments were performed in goldfish to determine the effects of a short-term exposure (24 h) to atrazine or diuron (0.5, 5, 50 microgram/L) on some behavior endpoints related to swimming and social activities. Observations were also made to assess the influence of such exposure on the behavioral responses of fish to the flow of a crude skin extract solution from conspecifics, active in social chemocommunication and producing alarm behaviors. Additive tests were run to check the behavioral responses of previously unexposed goldfish to the flow of a solution of atrazine- or diuron-contaminated water, at three concentrations (0.1, 1, 10 mg/L). Significant burst swimming reactions appeared in response to a 24-h exposure to atrazine, at the lowest concentration tested (0.5 microgram/L). A 24-h exposure to 5 microgram/L atrazine or diuron was found to induce various significant behavioral alterations in fish. At this concentration, both herbicides decreased grouping behavior and atrazine also increased surfacing activity. Herbicide-exposed fish showed a decreased grouping behavior during the flow of the skin extract solution. Sheltering was also decreased during the flow of the biological solution in fish exposed to atrazine. Moreover, fish exposed to diuron clearly displayed attraction responses to the flow of the skin solution. Previously unexposed fish showed a significant increase in burst swimming reactions in response to the flow of a solution of atrazine- or diuron-contaminated water, at all concentrations tested (0.1, 1, 10 mg/L). Furthermore, the diuron-contaminated flow was found to be significantly attractive at the highest concentration. These results indicate that a short-term exposure to a relatively low concentration (5 microgram/L) of atrazine or diuron can affect various behaviors of fish not only directly but also indirectly by altering the chemical perception of natural substances of eco-ethological importance. In consideration of the basic role of

  4. Influence of phosphate on the response of periphyton to atrazine exposure.

    PubMed

    Guasch, H; Lehmann, V; van Beusekom, B; Sabater, S; Admiraal, W

    2007-01-01

    After indications from the literature that nutrient concentrations may modify the toxicity of herbicides to natural periphyton communities, this study aims to provide experimental proof for atrazine. In this microcosm experiment, phosphate (P) addition did not ameliorate atrazine toxicity to periphyton. Three weeks of P addition did not increase atrazine tolerance (measured as EC50 in acute toxicity tests), whereas exposure to atrazine under conditions that were either P-limited or non-P-limited clearly reduced the development of algal biomass. Long-term exposure to atrazine induced tolerance of the community to the herbicide, and this was not influenced by P addition. Tolerance induction in this microcosm experiment has been compared with previously published field data from the same area of study and indicates that tolerance induction by atrazine may take place under atrazine exposure in streams as well as in microcosms. PMID:17061052

  5. Photolytic treatment of atrazine-contaminated water: products, kinetics, and reactor design.

    PubMed

    Ye, Xuejun; Chen, Daniel; Li, Kuyen; Wang, Bin; Hopper, Jack

    2007-08-01

    This study investigates the products, kinetics, and reactor design of atrazine photolysis under 254-nm ultraviolet-C (UVC) irradiation. With an initial atrazine concentration of 60 microg/L (60 ppbm), only two products remain in detectable levels. Up to 77% of decomposed atrazine becomes hydroxyatrazine, the major product. Both atrazine and hydroxyatrazine photodecompose following the first-order rate equation, but the hydroxyatrazine photodecomposition rate is significantly slower than that of atrazine. For atrazine photodecomposition, the rate constant is proportional to the square of UVC output, but inversely proportional to the reactor volume. For a photochemical reactor design, a series of equations are proposed to calculate the needed UVC output power, water treatment capacity, and atrazine outlet concentration.

  6. A Qualitative Meta-Analysis Reveals Consistent Effects of Atrazine on Freshwater Fish and Amphibians

    PubMed Central

    Rohr, Jason R.; McCoy, Krista A.

    2010-01-01

    Objective The biological effects of the herbicide atrazine on freshwater vertebrates are highly controversial. In an effort to resolve the controversy, we conducted a qualitative meta-analysis on the effects of ecologically relevant atrazine concentrations on amphibian and fish survival, behavior, metamorphic traits, infections, and immune, endocrine, and reproductive systems. Data sources We used published, peer-reviewed research and applied strict quality criteria for inclusion of studies in the meta-analysis. Data synthesis We found little evidence that atrazine consistently caused direct mortality of fish or amphibians, but we found evidence that it can have indirect and sublethal effects. The relationship between atrazine concentration and timing of amphibian metamorphosis was regularly nonmonotonic, indicating that atrazine can both accelerate and delay metamorphosis. Atrazine reduced size at or near metamorphosis in 15 of 17 studies and 14 of 14 species. Atrazine elevated amphibian and fish activity in 12 of 13 studies, reduced antipredator behaviors in 6 of 7 studies, and reduced olfactory abilities for fish but not for amphibians. Atrazine was associated with a reduction in 33 of 43 immune function end points and with an increase in 13 of 16 infection end points. Atrazine altered at least one aspect of gonadal morphology in 7 of 10 studies and consistently affected gonadal function, altering spermatogenesis in 2 of 2 studies and sex hormone concentrations in 6 of 7 studies. Atrazine did not affect vitellogenin in 5 studies and increased aromatase in only 1 of 6 studies. Effects of atrazine on fish and amphibian reproductive success, sex ratios, gene frequencies, populations, and communities remain uncertain. Conclusions Although there is much left to learn about the effects of atrazine, we identified several consistent effects of atrazine that must be weighed against any of its benefits and the costs and benefits of alternatives to atrazine use. PMID

  7. Induction of micronuclei and erythrocyte alterations in the catfish Clarias batrachus by 2,4-dichlorophenoxyacetic acid and butachlor.

    PubMed

    Ateeq, Bushra; Abul farah, M; Niamat Ali, M; Ahmad, Waseem

    2002-07-25

    The micronucleus test (MNT) in fish erythrocytes has increasingly been used to detect the genotoxic effects of environmental mutagens and its frequency is considered to reflect the genotoxic damage to cells, mainly the chromosomes. Besides, morphologically altered erythrocyte is taken as an index of cytotoxicity. Both parameters were used in the present study by two herbicides, 2,4-dichlorophenoxyacetic acid (2,4-D, in 25, 50 and 75ppm concentrations) and 2-chloro-2,6-diethyl-N-(butoxymethyl) acetanilide (butachlor, in 1, 2 and 2.5ppm concentrations) for genotoxic and cytotoxic endpoints. The study was carried out by an in vivo method on peripheral erythrocytes of catfish Clarias batrachus using multiple sampling times (48, 72 and 96h). Cytogenetic preparations were made by haematoxylin-eosin staining technique. Pycnotic and granular micronuclei (MN) were consistently observed irrespective of chemical tested. A wide range of altered cells was also observed. Echinocytes accompanied by altered nuclei and vacuoles were prominent feature of 2,4-D, whereas, anisochromasia and anisocytosis of erythrocytes were characteristic of butachlor. Increase in MN as well as altered cells frequencies were significant. A positive dose-response relationship in all exposures and sampling times was observed. Herbicides used were found to be genotoxic as well as cytotoxic in this fish. The suitability of the adopted parameters for the screening of the aquatic genotoxicants is discussed.

  8. Cytogenotoxicity assessment of monocrotophos and butachlor at single and combined chronic exposures in the fish Catla catla (Hamilton).

    PubMed

    Anbumani, S; Mohankumar, Mary N

    2015-04-01

    Cytogenotoxic effects in the form of micronuclei and deformed nucleus, nuclear buds, binucleated cells, vacuolated nucleus, vacuolated cytoplasm, echinocytes, and enucleus induced by two compounds belonging to two different chemical classes of agrochemicals (monocrotophos and butachlor) at sublethal concentrations (0.625, 1.3, and 2.3 ppm and 0.016, 0.032, and 0.064 ppm) in single and combined chronic exposures were studied under laboratory conditions for a period of 35 days in the economically important Indian fish Catla catla. Statistically significant duration-dependent increases in the frequencies of micronucleus (MN) and other cytological anomalies were observed. Compared to single exposures, a twofold increase in micronuclei frequency was noted at combined exposures indicating the synergistic phenomenon. Binucleated and enucleated cells appeared only in fishes exposed to sublethal concentrations of butachlor. The present study is the first of its kind in exploring a significant positive correlation between micronuclei and other nuclear anomalies suggesting them as new possible biomarkers of genotoxicity after agrochemical exposures. The study highlights the sensitivity of the assay in exploring various predictive biomarkers of genotoxic and cytotoxic events and also elicits the synergistic effects of agrochemicals in apparently healthy fishes. C. catla can be considered as a suitable aquatic biomonitoring sentinel species of contaminated water bodies.

  9. Fast atrazine photodegradation in water by pulsed light technology.

    PubMed

    Baranda, Ana Beatriz; Barranco, Alejandro; de Marañón, Iñigo Martínez

    2012-03-01

    Pulsed light technology consists of a successive repetition of short duration (325μs) and high power flashes emitted by xenon lamps. These flashlamps radiate a broadband emission light (approx. 200-1000 nm) with a considerable amount of light in the short-wave UV spectrum. In the present work, this technology was tested as a new tool for the degradation of the herbicide atrazine in water. To evaluate the presence and evolution with time of this herbicide, as well as the formation of derivatives, liquid chromatography-mass spectrometry (electrospray ionization) ion trap operating in positive mode was used. The degradation process followed first-order kinetics. Fluences about 1.8-2.3 J/cm(2) induced 50% reduction of atrazine concentration independently of its initial concentration in the range 1-1000 μg/L. Remaining concentrations of atrazine, below the current legal limit for pesticides, were achieved in a short period of time. While atrazine was degraded, no chlorinated photoproducts were formed and ten dehalogenated derivatives were detected. The molecular structures for some of these derivatives could be suggested, being hydroxyatrazine the main photoproduct identified. The different formation profiles of photoproducts suggested that the degradation pathway may include several successive and competitive steps, with subsequent degradation processes taking part from the already formed degradation products. According to the degradation efficiency, the short treatment time and the lack of chloroderivatives, this new technology could be considered as an alternative for water treatment.

  10. Bioavailability of organoclay formulations of atrazine in soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pesticide formulations based on organoclays have been proposed to prolong the efficacy and reduce the environmental impact of pesticides in soil. This research addressed the question of whether organoclay-based formulations of atrazine are irreversibly sorbed or are bioavailable for bacterial degrad...

  11. REGIONAL MODELING OF THE ATMOSPHERIC TRANSPORT AND DEPOSITION OF ATRAZINE

    EPA Science Inventory

    A version of the Community Multiscale Air Quality (CMAQ) model has been developed by the U.S. EPA that is capable of addressing the atmospheric fate, transport and deposition of some common trace toxics. An initial, 36-km rectangular grid-cell application for atrazine has been...

  12. ATRAZINE DISPOSITION IN PREGNANT AND LACTATING LONG-EVANS RATS

    EPA Science Inventory

    Atrazine (ATR) is a widely used herbicide shown to delay early mammary development in female offspring of gestationally exposed rats. The effects of ATR can be induced by in utero exposure and/or suckling from a dam exposed during late pregnancy, but ATR is reported to have a hal...

  13. THE LOADINGS, TRANSPORT, AND FATE OF ATRAZINE IN LAKE MICHIGAN

    EPA Science Inventory

    A lake wide atrazine model was developed to gain insight into the transport and fate of the herbicide in Lake Michigan. An important part of the analysis was the preparation of historical loading estimates from both tributaries and the atmosphere. Historical tributary loading est...

  14. ATRAZINE DISRUPTS THE HYPOTHALAMIC CONTROL OF PITUITARY-OVARIAN FUNCTION

    EPA Science Inventory

    The chloro-S-triazine herbicides (i.e., atrazine, simazine, cyanazine) constitute the largest group of herbicides sold in the United States. Despite their extensive usage, relatively little is known about the possible human-health effects and mechanism(s) of action of these compo...

  15. Toxoxity characteristics of the 2-chlorotriazines atrazine and simazine

    SciTech Connect

    Hauswirth, J.W.

    1996-10-01

    Atrazine and simazine are herbicides used broadly in agriculture to control annual grasses and broadleaf weeds. An extensive database on the toxicity of these triazines has been developed to support their use in agriculture. Atrazine and simazine have very low levels of acute toxicity with oral LD{sub 50}s of >3000 mg/kg in rats. A total of 37 mutagenicity studies have been conducted on atrazine and 34 on simazine. A weight-of-the-evidence evaluation of the mutagenicity data leads to the conclusion that neither triazine possesses genotoxic activity. Oncogenicity studies in three strains of mice are negative for both atrazine and simazine. Neither triazine is oncogenic to male Sprague-Dawley (SD) rats or to male and female Fischer 344 rats. However, in female SD rats both triazines induce the early occurrence and/or increased incidence of mammary gland tumors. Results of additional studies suggest that endocrinologic changes related to triazine administration are likely responsible for the mammary gland effects in female SD rats and that a threshold exists for these effects.

  16. Veterinary antibiotic effects on atrazine degradation and soil microorganisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Veterinary antibiotics (VAs) in manure applied to agricultural lands may change agrichemical degradation by altering soil microbial community structure or function. The objectives of this study were to investigate the influence of two VAs, sulfamethazine (SMZ) and oxytetracycline (OTC), on atrazine ...

  17. Study of atrazine effects on Pacific oyster, Crassostrea gigas, haemocytes.

    PubMed

    Gagnaire, B; Renault, T; Bouilly, K; Lapegue, S; Thomas-Guyon, H

    2003-01-01

    Shellfish farming is an important economic activity around the world. This activity often takes place in areas subjected to various recurring pollutions. The recrudescent use of herbicides in agriculture including atrazine implies pollutant transfer towards aquatic environment in estuarine areas. Harmful effects of such substances on animals in marine environment, particularly on cultured bivalves, are poorly documented. Bivalve molluscs such as mussels and oysters have been postulated as ideal indicator organisms because of their way of life. They filter large volumes of seawater and may therefore accumulate and concentrate contaminants within their tissues. Moreover, development of techniques allowing effect analysis of such compounds on bivalve biology may lead to the development of diagnosis tools adapted to analyze pollutant transfer towards estuarine areas. In this context, influence of atrazine on defence mechanisms was analyzed in Pacific oysters, Crassostrea gigas. Atrazine was tested in vitro and in vivo on oyster haemocytes, and its effects were analyzed by flow cytometry. Haemocyte viability, cell cycle and cellular activities were monitored. Atrazine induced no significant effect in oyster under tested conditions except for peroxidase activity.

  18. Glufosinate and Ammonium Sulfate Inhibits Atrazine Degradation in Adapted Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The co-application of glufosinate with nitrogen fertilizers may alter atrazine co-metabolism, thereby extending the herbicide’s residual weed control in adapted soils. The objective of this study was to assess the effects of glufosinate, ammonium sulfate, and the combination of glufosinate and ammo...

  19. SORPTION OF VINCLOZOLIN AND ATRAZINE ON FOUR GEOSORBENTS

    EPA Science Inventory

    The objectives of this study were to evaluate the magnitude and kinetics of vinclozolin and atrazine sorption on one surface soil and three freshwater sediments using batch and column techniques. Data from miscible displacement column studies were analyzed using a two-domain, fir...

  20. Microbial atrazine breakdown in a karst groundwater system and its effect on ecosystem energetics.

    PubMed

    Iker, Brandon C; Kambesis, Pat; Oehrle, Stuart A; Groves, Chris; Barton, Hazel A

    2010-01-01

    In the absence of sunlight energy, microbial community survival in subterranean aquifers depends on integrated mechanisms of energy and nutrient scavenging. Because karst aquifers are particularly sensitive to agricultural land use impacts due to rapid and direct hydrologic connections for pollutants to enter the groundwater, we examined the fate of an exogenous pesticide (atrazine) into such an aquifer and its impact on microbial ecosystem function. Atrazine and its degradation product deethylatrazine (DEA) were detected in a fast-flowing karst aquifer underlying atrazine-impacted agricultural land. By establishing microbial cultures with sediments from a cave conduit within this aquifer, we observed two distinct pathways of microbial atrazine degradation: (i) in cave sediments previously affected by atrazine, apparent surface-derived catabolic genes allowed the microbial communities to rapidly degrade atrazine via hydroxyatrazine, to cyanuric acid, and (ii) in low-impact sediments not previously exposed to this pesticide, atrazine was also degraded by microbial activity at a much slower rate, with DEA as the primary degradation product. In sediments from both locations, atrazine affected nitrogen cycling by altering the abundance of nitrogen dissimulatory species able to use nitrogenous compounds for energy. The sum of these effects was that the presence of atrazine altered the natural microbial processes in these cave sediments, leading to an accumulation of nitrate. Such changes in microbial ecosystem dynamics can alter the ability of DEA to serve as a proxy for atrazine contamination and can negatively affect ecosystem health and water quality in karst aquifers.

  1. Toxicity of atrazine and its bioaccumulation and biodegradation in a green microalga, Chlamydomonas mexicana.

    PubMed

    Kabra, Akhil N; Ji, Min-Kyu; Choi, Jaewon; Kim, Jung Rae; Govindwar, Sanjay P; Jeon, Byong-Hun

    2014-11-01

    This study evaluated the toxicity of herbicide atrazine, along with its bioaccumulation and biodegradation in the green microalga Chlamydomonas mexicana. At low concentration (10 μg L(-1)), atrazine had no profound effect on the microalga, while higher concentrations (25, 50, and 100 μg L(-1)) imposed toxicity, leading to inhibition of cell growth and chlorophyll a accumulation by 22 %, 33 %, and 36 %, and 13 %, 24 %, and 27 %, respectively. Atrazine 96-h EC50 for C. mexicana was estimated to be 33 μg L(-1). Microalga showed a capability to accumulate atrazine in the cell and to biodegrade the cell-accumulated atrazine resulting in 14-36 % atrazine degradation at 10-100 μg L(-1). Increasing atrazine concentration decreased the total fatty acids (from 102 to 75 mg g(-1)) and increased the unsaturated fatty acid content in the microalga. Carbohydrate content increased gradually with the increase in atrazine concentration up to 15 %. This study shows that C. mexicana has the capability to degrade atrazine and can be employed for the remediation of atrazine-contaminated streams.

  2. Bioremediation strategies for removal of residual atrazine in the boreal groundwater zone.

    PubMed

    Nousiainen, Aura O; Björklöf, Katarina; Sagarkar, Sneha; Nielsen, Jeppe Lund; Kapley, Atya; Jørgensen, Kirsten S

    2015-12-01

    Strategies for bioremediation of atrazine, a pesticide commonly polluting groundwater in low concentrations, were studied in two boreal nonagricultural soils. Atrazine was not mineralized in soil without bioremediation treatments. In biostimulation treatment with molasses, up to 52% of atrazine was mineralized at 10 °C, even though the degradation gene copy numbers did not increase. Incubations with radioactively labeled atrazine followed by microautoradiographic analysis revealed that bioremediation strategies increased the relative proportion of active degraders from 0.3 up to 1.9% of the total bacterial count. These results indicate that atrazine degradation might not solely be facilitated by atzA/trzN-atzB genes. In combined biostimulation treatment using citrate or molasses and augmentation with Pseudomonas citronellolis ADP or Arthrobacter aurescens strain TC1, up to 76% of atrazine was mineralized at 30 °C, and the atrazine degradation gene numbers increased up to 10(7) copies g(-1) soil. Clone libraries from passive samplers in groundwater monitoring wells revealed the presence of phylogenetic groups formerly shown to include atrazine degraders, and the presence of atrazine degradation genes atzA and atzB. These results show that the mineralization of low concentrations of atrazine in the groundwater zone at low temperatures is possible by bioremediation treatments.

  3. Exploring bacterial community structure and function associated with atrazine biodegradation in repeatedly treated soils.

    PubMed

    Fang, Hua; Lian, Jianjun; Wang, Huifang; Cai, Lin; Yu, Yunlong

    2015-04-01

    Substantial application of the herbicide atrazine in agriculture leads to persistent contamination, which may damage the succeeding crops and pose potential threats to soil ecology and environmental health. Here, the degradation characteristics of atrazine and dynamic change of soil bacterial community structure and function as well as their relations were studied during three repeated treatments at the recommended, double, and five-fold doses. The results showed that the degradation half-life of atrazine obviously decreased with increased treatment frequency. Soil microbial functional diversity displayed a variation trend of suppression-recovery-stimulation, which was associated with increased degradation rate of atrazine. 16S amplicon sequencing was conducted to explore bacterial community structure and correlate the genus to potential atrazine degradation. A total of seven potentially atrazine-degrading bacterial genera were found including Nocardioides, Arthrobacter, Bradyrhizobium, Burkholderia, Methylobacterium, Mycobacterium, and Clostridium. These bacterial genera showed almost complete atrazine degradation pathways including dechlorination, dealkylation, hydroxylation, and ring cleavage. Furthermore, the relative abundance of four of them (i.e., Nocardioides, Arthrobacter, Methylobacterium, and Bradyrhizobium) increased with treatment frequency and atrazine concentration, suggesting that they may participate in atrazine degradation during repeated treatments. Our findings reveal the potential relationship between atrazine degradation and soil bacterial community structure in repeatedly treated soils.

  4. [Efficiency of atrazine degradation by O3/H2O2].

    PubMed

    Li, Shao-Feng; Liang, Yuan; Zhang, Rong-Quan; Ye, Fei

    2009-05-15

    The endocrine disrupter Atrazine was oxidized by O3/H2O2 system and the products were analyzed to assess the degradation efficiency of Atrazine. When it's initial content was 2 mg/L and O3 dosage was 7.5 mg/L, Atrazine was removed about 27.2% after 5 minutes. Under the same condition, H2O2/O3 molar ratio was 0.75, Atrazine maximum removal rate reached 96.5%, which suggested that Atrazine could be degraded by O3/H2O2 system effectively. Ion Chromatography (IC) analysis showed that concentrations of chloride and nitrate ions were increasing along with the Atrazine content decreasing. Gas Chromatography-Mass spectrometry (GC-MS) and Liquid Chromatography-Mass spectrometry chromatograms (LC-MS) analyzing illuminated the existence of de-ethyl-atrazine, de-isopropyl-atrazine and de-chloro-atrazine, which indicated the Atrazine could not be destroyed completely by O3/H2O2 system. Consequently, it should be combined with GAC (Granular Activated Carbon) or other techniques while used as primary treatment unit or emergency measure.

  5. The combined stress effects of atrazine and cadmium on the earthworm Eisenia fetida.

    PubMed

    Wang, Jin-Hua; Zhu, Lu-Sheng; Meng, Yan; Wang, Jun; Xie, Hui; Zhang, Qing-Ming

    2012-09-01

    To assess the combined toxic effects of atrazine and cadmium on earthworms, specimens of Eisenia fetida were exposed in artificial soil to three concentrations of atrazine (0, 0.5, and 2.5 mg kg(-1)) and a range of concentrations of cadmium (Cd; 0, 0.03, 0.3, and 3.0 mg kg(-1)) both singly and as mixtures. The DNA damage and internal atrazine and cadmium concentrations were assessed in earthworms on days 7, 14, 21, and 28 of the treatment. The results showed that the olive tail moments (OTMs) at individual atrazine and cadmium concentrations were significantly higher than those of the controls (p < 0.01). As exposure to atrazine or cadmium progressed, the OTMs increased and the maximum value occurred on day 28. In all combined treatments, the OTMs were much less than those of the sum of individual atrazine and cadmium OTMs, suggesting that the combined effects of atrazine and cadmium were less than additive. The less than additive toxicity of atrazine and cadmium might be due to the formation of atrazine-cadmium complexes or the activation of detoxification isozymes. Moreover, there was a significant correlation between internal atrazine or cadmium concentrations and DNA damage in most exposures, indicating that body residues were consistent with toxicity response.

  6. Photocatalytic atrazine degradation by synthetic minerals, atmospheric aerosols, and soil particles.

    PubMed

    Lackhoff, Marion; Niessner, Reinhard

    2002-12-15

    In this work, the photocatalytic atrazine degradation by seven synthetic minerals and five environmental particle samples was examined to investigate a possible contribution of photocatalysis to the abiotic degradation of atrazine in the environment. Particle suspensions containing 500 ng/L atrazine were irradiated with a sun simulator, and the atrazine degradation was monitored by enzyme-linked immunosorbent assay (ELISA). Atrazine detection by ELISA proved to be an useful analytical tool because of low cross-reactivity of atrazine metabolites and high sensitivity with detection limits in the lower nanograms per liter range. The atrazine degradation followed first-order kinetics, and the obtained rate coefficients were compared with the rate of direct photolysis. Known photocatalysts, such as TiO2 and ZnO, showed the expected fast photocatalytic degradation (k = 27-327 x 10(-3) min(-1)) of atrazine. The degradation rates detected upon irradiation of titanium-, zinc-, or iron-containing minerals were orders of magnitudes lower (k = 0.15-0.70 x 10(-3) min(-1)) but still significantly faster than direct photolysis without particles (k = 0.10 x 10(-3) min(-1)). With environmental particle samples (soot, fly ash, sand, road dust, and volcanic ash), however, no significant photocatalytic activity was observed (k = 0.07-0.16 x 10(-3) min(-1)). The atrazine degradation rates were in the range of direct photolysis. Thus photocatalysis by aerosol or soil particles appears not to enhance abiotic atrazine degradation in the environment.

  7. Protective effects of vitamin E against atrazine-induced genotoxicity in rats.

    PubMed

    Singh, Mohan; Kaur, Pushpindar; Sandhir, Rajat; Kiran, Ravi

    2008-07-31

    Atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) is one of the most commonly used herbicides to control grasses and weeds. The widespread contamination and persistence of atrazine residues in the environment has resulted in human exposure. Vitamin E is a primary antioxidant that plays an important role in protecting cells against toxicity by inactivating free radicals generated following pesticides exposure. The present study was undertaken to investigate the protective effect of vitamin E against atrazine-induced genotoxicity. Three different methods: gel electrophoresis, comet assay and micronucleus test were used to assess the atrazine-induced genotoxicity and to evaluate the protective effects of vitamin E. Atrazine was administered to male rats at a dose of 300 mg/kg body weight for a period of 7, 14 and 21 days. There was a significant increase (P<0.001) in tail length of comets from blood and liver cells treated with atrazine as compared to controls. Co-administration of vitamin E (100 mg/kg body weight) along with atrazine resulted in decrease in tail length of comets as compared to the group treated with atrazine alone. Micronucleus assay revealed a significant increase (P<0.001) in the frequency of micronucleated cells (MNCs) following atrazine administration. In the animals administrated vitamin E along with atrazine there was a significant decrease in percentage of micronuclei as compared to atrazine treated rats. The increase in frequency of micronuclei in liver cells and tail length of comets confirm genotoxicity induced by atrazine in blood and liver cells. In addition, the findings clearly demonstrate protective effect of vitamin E in attenuating atrazine-induced DNA damage. PMID:18582598

  8. EVALUATION OF PITUITARY AND ADRENAL HORMONE RELEASE FOLLOWING EXPOSURE TO ATRAZINE AND ITS METABOLITE DEISOPROPYL-ATRAZINE (DIA), USING TISSUE PERIFUSION

    EPA Science Inventory

    Atrazine (ATR) is one of the most widely used herbicides in the United States, with current total annual use of approximately 76 million pounds of active ingredient. Previous work in our laboratory has shown that ATR and its metabolite deisopropyl-atrazine (DIA) induce a dose-dep...

  9. In vivo genotoxicity evaluation of atrazine and atrazine-based herbicide on fish Carassius auratus using the micronucleus test and the comet assay.

    PubMed

    Cavas, Tolga

    2011-06-01

    Atrazine is a selective triazine herbicide used to control broadleaf and grassy weeds mainly in corn, sorghum, sugarcane, pineapple, and other crops, and in conifer reforestation planting fields. It has been showed that atrazine is one of the most frequently detected pesticides in agricultural streams and rivers, over the past two decades. Although the toxic properties of atrazine are well known, the data on the genotoxic effects of atrazine on aquatic organisms are rather scarce. Thus, in the present study we aimed to evaluate the genotoxic effects of atrazine and an atrazine-based herbicide (Gesaprim®) on a model fish species Carassius auratus L., 1758, (Pisces: Cyprinidae) using the micronucleus test and the comet assay in peripheral blood erythrocytes. Fish were exposed to 5, 10 and 15 μg/L atrazine and to its commercial formulation for 2, 4 and 6 days. Ethyl methane sulfonate (EMS) at a single dose of 5 mg/L was used as positive control. Our results revealed significant increases in the frequencies of micronuclei and DNA strand breaks in erythrocytes of C. auratus, following exposure to commercial formulation of atrazine and thus demonstrated the genotoxic potential of this pesticide on fish.

  10. 2004 National Atrazine Occurrence Monitoring Program using the Abraxis ELISA method.

    PubMed

    Graziano, Nicole; McGuire, Michael J; Roberson, Alan; Adams, Craig; Jiang, Hua; Blute, Nicole

    2006-02-15

    The goal of this project was to gain a better understanding of atrazine occurrence in the United States by surveying drinking water utilities' sources and finished water for atrazine on a weekly basis for seven months. Atrazine is a contaminant of interest because the United States Environmental Protection Agency (USEPA) has found short-term atrazine exposure above the drinking water maximum contaminant level (MCL) to potentially cause heart, lung, and kidney congestion, low blood pressure, muscle spasms, weight loss, and damage to the adrenal glands. Long-term exposure to atrazine concentrations above the drinking water MCL has been linked to weight loss, cardiovascular damage, retinal and muscle degeneration, and cancer. This survey effort improved upon previously conducted atrazine surveys through intensive, high frequency sampling (participating plants sampled their raw and finished water on a weekly basis for approximately seven months). Such an intensive effort allowed the authors to gain a better understanding of short-term atrazine occurrence and its variability in drinking water sources. This information can benefit the drinking water industry by facilitating (1) better atrazine occurrence management (i.e., awareness when plants may be more susceptible to atrazine), (2) more efficient atrazine control (e.g., effective treatment alternatives and more effective response to atrazine occurrence), and (3) treatment cost reduction (e.g., efficient atrazine control can result in substantial cost savings). Forty-seven drinking watertreatment plants located primarily in the Midwestern United States participated in the survey and sampled their raw and finished water on a weekly basis from March through October. Samples were analyzed using the Abraxis enzyme-linked immunosorbent assay (ELISA) test kit. Confirmation samples for quality assurance/quality control (QA/QC) purposes were analyzed using solid-phase extraction (SPE) followed by gas chromatography mass

  11. Atrazine is an immune disruptor in adult northern leopard frogs (Rana pipiens).

    PubMed

    Brodkin, Marc A; Madhoun, Hareth; Rameswaran, Muthuramanan; Vatnick, Itzick

    2007-01-01

    Atrazine, the most widely used herbicide in the United States, has been shown in several studies to be an endocrine disruptor in adult frogs. Results from this study indicate that atrazine also functions as an immune disruptor in frogs. Exposure to atrazine (21 ppb for 8 d) affects the innate immune response of adult Rana pipiens in similar ways to acid exposure (pH 5.5), as we have previously shown. Atrazine exposure suppressed the thioglycollate-stimulated recruitment of white blood cells to the peritoneal cavity to background (Ringer exposed) levels and also decreased the phagocytic activity of these cells. Unlike acid exposure, atrazine exposure did not cause mortality. Our results, from a dose-response study, indicate that atrazine acts as an immune disruptor at the same effective doses that it disrupts the endocrine system.

  12. A study of the mechanism of butachlor-associated gastric neoplasms in Sprague-Dawley rats.

    PubMed

    Thake, D C; Iatropoulos, M J; Hard, G C; Hotz, K J; Wang, C X; Williams, G M; Wilson, A G

    1995-05-01

    Long term administration of butachlor to Sprague-Dawley rats in a previous bioassay, resulted in the induction of gastric neoplasms which occurred only in the highest dose group (3000 ppm in the diet), primarily in females and specifically in the fundic region. The tumors were a composite of highly undifferentiated enterochromaffin-like (ECL) cells and mucus producing cells with morphologic characteristics unlike those previously described in the rat stomach. Mucosal atrophy of marked intensity was a consistent feature of the gastric mucosa in animals from the highest dose group. An additional long term study was conducted in female Sprague-Dawley rats at dietary levels of 0, 100, 1000 and 3000 ppm to explore the mechanism(s) involved in the formation of these neoplasms. Cell proliferation was evaluated in both fundic and pyloric regions of the stomachs of rats at multiple time periods from 14 days to 26 months. Mucosal thickness was determined in the fundic region at the same time intervals as were used for cell proliferation studies. Gastric pH and gastric acid production were measured after approximately 21 months of exposure. Serum gastrin levels were analyzed at 14, 60, and 120 days and at 6, 18 and 20 months. Cholecystokinin (CCK)/gastrin receptor binding studies were conducted on samples of four tumors and pooled fundic mucosa from five animals in the control group. Cell proliferation was increased in both the neck and base regions of the fundic mucosa at nearly all time points measured from 14 days to 26 months. The magnitude of the changes in the base region were substantially greater than those in the neck region. Fundic mucosal thickness was decreased beginning at the 30-day time point and continued at all intervals, being less than one half that of controls at 20 and 26 months. Gastric pH in rats from the highest dose was elevated to nearly twice control levels at 21 months. Gastric acid secretion was dramatically decreased in animals from the 3000 ppm

  13. Evaluation of the side effects of poly(epsilon-caprolactone) nanocapsules containing atrazine towards maize plants

    NASA Astrophysics Data System (ADS)

    Oliveira, Halley; Stolf-Moreira, Renata; Martinez, Cláudia; Sousa, Gustavo; Grillo, Renato; de Jesus, Marcelo; Fraceto, Leonardo

    2015-10-01

    Poly(epsilon-caprolactone) (PCL) nanocapsules have been used as a carrier system for the herbicide atrazine, which is commonly applied to maize. We demonstrated previously that these atrazine containing polymeric nanocapsules were ten-fold more effective in the control of mustard plants (a target species), as compared to a commercial atrazine formulation. Since atrazine can have adverse effects on non-target crops, here we analyzed the effect of encapsulated atrazine on growth, physiological and oxidative stress parameters of soil-grown maize plants (Zea mays L.). One day after the post-emergence treatment with PCL nanocapsules containing atrazine (1 mg mL-1), maize plants presented 15 and 21 % decreases in maximum quantum yield of photosystem II and in net CO2 assimilation rate, respectively, as compared to water-sprayed plants. The same treatment led to a 1.8-fold increase in leaf lipid peroxidation in comparison with control plants. However, all of these parameters were unaffected four and eight days after the application of encapsulated atrazine. These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide. When encapsulated atrazine was applied at a ten-fold lower concentration (0.1 mg mL-1), a dosage that is still effective for weed control, no effects were detected even shortly after application. Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth. Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine. Overall, these results suggested that the use of PCL nanocapsules containing atrazine did not lead to persistent side effects in maize plants, and that the technique could offer a safe tool for weed control without affecting crop growth.

  14. Evaluation of the side effects of poly(epsilon-caprolactone) nanocapsules containing atrazine toward maize plants.

    PubMed

    Oliveira, Halley C; Stolf-Moreira, Renata; Martinez, Cláudia B R; Sousa, Gustavo F M; Grillo, Renato; de Jesus, Marcelo B; Fraceto, Leonardo F

    2015-01-01

    Poly(epsilon-caprolactone) (PCL) nanocapsules have been used as a carrier system for the herbicide atrazine, which is commonly applied to maize. We demonstrated previously that these atrazine containing polymeric nanocapsules were 10-fold more effective in the control of mustard plants (a target species), as compared to a commercial atrazine formulation. Since atrazine can have adverse effects on non-target crops, here we analyzed the effect of encapsulated atrazine on growth, physiological and oxidative stress parameters of soil-grown maize plants (Zea mays L.). One day after the post-emergence treatment with PCL nanocapsules containing atrazine (1 mg mL(-1)), maize plants presented 15 and 21% decreases in maximum quantum yield of photosystem II (PSII) and in net CO2 assimilation rate, respectively, as compared to water-sprayed plants. The same treatment led to a 1.8-fold increase in leaf lipid peroxidation in comparison with control plants. However, all of these parameters were unaffected 4 and 8 days after the application of encapsulated atrazine. These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide. When encapsulated atrazine was applied at a 10-fold lower concentration (0.1 mg mL(-1)), a dosage that is still effective for weed control, no effects were detected even shortly after application. Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth. Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine. Overall, these results suggested that the use of PCL nanocapsules containing atrazine did not lead to persistent side effects in maize plants, and that the technique could offer a safe tool for weed control without affecting crop growth

  15. Evaluation of the side effects of poly(epsilon-caprolactone) nanocapsules containing atrazine toward maize plants

    PubMed Central

    Oliveira, Halley C.; Stolf-Moreira, Renata; Martinez, Cláudia B. R.; Sousa, Gustavo F. M.; Grillo, Renato; de Jesus, Marcelo B.; Fraceto, Leonardo F.

    2015-01-01

    Poly(epsilon-caprolactone) (PCL) nanocapsules have been used as a carrier system for the herbicide atrazine, which is commonly applied to maize. We demonstrated previously that these atrazine containing polymeric nanocapsules were 10-fold more effective in the control of mustard plants (a target species), as compared to a commercial atrazine formulation. Since atrazine can have adverse effects on non-target crops, here we analyzed the effect of encapsulated atrazine on growth, physiological and oxidative stress parameters of soil-grown maize plants (Zea mays L.). One day after the post-emergence treatment with PCL nanocapsules containing atrazine (1 mg mL−1), maize plants presented 15 and 21% decreases in maximum quantum yield of photosystem II (PSII) and in net CO2 assimilation rate, respectively, as compared to water-sprayed plants. The same treatment led to a 1.8-fold increase in leaf lipid peroxidation in comparison with control plants. However, all of these parameters were unaffected 4 and 8 days after the application of encapsulated atrazine. These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide. When encapsulated atrazine was applied at a 10-fold lower concentration (0.1 mg mL−1), a dosage that is still effective for weed control, no effects were detected even shortly after application. Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth. Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine. Overall, these results suggested that the use of PCL nanocapsules containing atrazine did not lead to persistent side effects in maize plants, and that the technique could offer a safe tool for weed control without affecting crop growth

  16. Draft Genome Sequence of Atrazine-Utilizing Bacteria Isolated from Indian Agricultural Soil

    PubMed Central

    Sagarkar, Sneha; Bhardwaj, Pooja; Yadav, Trilok C.; Qureshi, Asifa; Khardenavis, Anshuman; Purohit, Hemant J.

    2014-01-01

    We report the draft genome sequences of two tropical bacterial isolates capable of degrading the herbicide atrazine. Alcaligenes sp. strain EGD-AK7 and Arthrobacter sp. strain AK-YN10 were isolated from Indian agricultural soil in which sugarcane is grown, with a reported history of atrazine use. EGD-AK7 has the atzABCDEF genes and AK-YN10 has the trzN and atzBC genes for atrazine degradation. PMID:24407646

  17. Effect of cow slurry amendment on atrazine dissipation and bacterial community structure in an agricultural Andisol.

    PubMed

    Briceño, G; Jorquera, M A; Demanet, R; Mora, M L; Durán, N; Palma, G

    2010-06-15

    Atrazine is a commonly used herbicide for maize production in Chile, but it has recently been shown to be ineffective in soils that receive applications of cow slurries generated from the dairy industry. This effect may be caused either by the sorption of the pesticide to organic matter or more rapid degradation in slurry-amended soils. The objectives of this study were to evaluate the effects of cow slurry on atrazine dissipation, the formation of atrazine metabolites and the modification of bacterial community in Andisol. The cow slurry was applied at doses of 100,000-300,000 Lha(-1). After 4 weeks, atrazine was applied to the slurry-amended soils at concentrations of 1-3 mg kg(-1). The amounts of atrazine and its metabolites were determined by high performance liquid chromatography (HPLC). The soil microbial community was monitored by measurement of CO(2) evolution and changes in bacterial community using PCR-DGGE of 16S rRNA genes. The results show that cow slurry applications had no effect on atrazine dissipation, which had a half-life of 15-19 days. The atrazine metabolites were detected after 20 days and were significantly higher in soils amended with the slurry at both 20 and 40 days after application of the herbicide. Respiration rates were elevated after 10 days in all soils with atrazine addition. Both the atrazine and slurry amendments altered the bacterial community structures, indicated by the appearance of specific bands in the DGGE gels after 10 days. Cloning and sequencing of the 16S rRNA genes from the DGGE gels showed that the bands represented various genera of beta-proteobacteria that appeared in response to atrazine. According to our results, further field studies are required to explain the lower effectiveness of atrazine in weed control. These studies may include the effect of dissolved organic carbon on the atrazine mobility.

  18. Nanoencapsulation Enhances the Post-Emergence Herbicidal Activity of Atrazine against Mustard Plants.

    PubMed

    Oliveira, Halley Caixeta; Stolf-Moreira, Renata; Martinez, Cláudia Bueno Reis; Grillo, Renato; de Jesus, Marcelo Bispo; Fraceto, Leonardo Fernandes

    2015-01-01

    Poly(epsilon-caprolactone) (PCL) nanocapsules have been recently developed as a modified release system for atrazine, an herbicide that can have harmful effects in the environment. Here, the post-emergence herbicidal activity of PCL nanocapsules containing atrazine was evaluated using mustard (Brassica juncea) as target plant species model. Characterization of atrazine-loaded PCL nanocapsules by nanoparticle tracking analysis indicated a concentration of 7.5 x 10(12) particles mL(-1) and an average size distribution of 240.7 nm. The treatment of mustard plants with nanocapsules carrying atrazine at 1 mg mL(-1) resulted in a decrease of net photosynthesis and PSII maximum quantum yield, and an increase of leaf lipid peroxidation, leading to shoot growth inhibition and the development of severe symptoms. Time course analysis until 72 h after treatments showed that nanoencapsulation of atrazine enhanced the herbicidal activity in comparison with a commercial atrazine formulation. In contrast to the commercial formulation, ten-fold dilution of the atrazine-containing nanocapsules did not compromise the herbicidal activity. No effects were observed when plants were treated with nanocapsules without herbicide compared to control leaves sprayed with water. Overall, these results demonstrated that atrazine-containing PCL nanocapsules provide very effective post-emergence herbicidal activity. More importantly, the use of nanoencapsulated atrazine enables the application of lower dosages of the herbicide, without any loss of efficiency, which could provide environmental benefits. PMID:26186597

  19. Nanoencapsulation Enhances the Post-Emergence Herbicidal Activity of Atrazine against Mustard Plants

    PubMed Central

    Oliveira, Halley Caixeta; Stolf-Moreira, Renata; Martinez, Cláudia Bueno Reis; Grillo, Renato; de Jesus, Marcelo Bispo; Fraceto, Leonardo Fernandes

    2015-01-01

    Poly(epsilon-caprolactone) (PCL) nanocapsules have been recently developed as a modified release system for atrazine, an herbicide that can have harmful effects in the environment. Here, the post-emergence herbicidal activity of PCL nanocapsules containing atrazine was evaluated using mustard (Brassica juncea) as target plant species model. Characterization of atrazine-loaded PCL nanocapsules by nanoparticle tracking analysis indicated a concentration of 7.5 x 1012 particles mL-1 and an average size distribution of 240.7 nm. The treatment of mustard plants with nanocapsules carrying atrazine at 1 mg mL-1 resulted in a decrease of net photosynthesis and PSII maximum quantum yield, and an increase of leaf lipid peroxidation, leading to shoot growth inhibition and the development of severe symptoms. Time course analysis until 72 h after treatments showed that nanoencapsulation of atrazine enhanced the herbicidal activity in comparison with a commercial atrazine formulation. In contrast to the commercial formulation, ten-fold dilution of the atrazine-containing nanocapsules did not compromise the herbicidal activity. No effects were observed when plants were treated with nanocapsules without herbicide compared to control leaves sprayed with water. Overall, these results demonstrated that atrazine-containing PCL nanocapsules provide very effective post-emergence herbicidal activity. More importantly, the use of nanoencapsulated atrazine enables the application of lower dosages of the herbicide, without any loss of efficiency, which could provide environmental benefits. PMID:26186597

  20. Atrazine and glyphosate dynamics in a lotic ecosystem: the common snapping turtle as a sentinel species.

    PubMed

    Douros, Derrick L; Gaines, Karen F; Novak, James M

    2015-03-01

    Atrazine and glyphosate are two of the most common pesticides used in the US Midwest that impact water quality via runoff, and the common snapping turtle (Chelydra serpentina) is an excellent indicator species to monitor these pesticides especially in lotic systems. The goals of this study were to (1) quantify atrazine, the atrazine metabolite diaminochlorotriazine (DACT), and glyphosate burdens in common snapping turtle tissue from individuals collected within the Embarras River in Illinois; (2) quantify atrazine, DACT, and glyphosate loads in water from the aquatic habitats in which common snapping turtles reside; and (3) investigate tissue loads based on turtle morphology and habitat choice. Concentrations of atrazine, DACT, and glyphosate in tissue did not show any relationship with lake habitat, carapace length, width, or mass. Both atrazine and glyphosate tissue samples varied as a function of site (river vs. lake), but DACT did not. Atrazine and glyphosate concentrations in water samples showed a linear effect on distance from the reservoir spillway and a deviation from linearity. Water column concentrations of all three contaminants varied across capture sites, but atrazine water concentration did not influence DACT water concentration nor did it exhibit a site interaction. Water atrazine and glyphosate concentrations were greater than tissue concentrations, whereas DACT water and tissue concentrations did not differ. This study showed that turtles are useful in long-term pesticide monitoring, and because DACT as a metabolite is less sensitive to variation, it should be considered as a preferred biomarker for pesticide runoff. PMID:25678354

  1. In Vitro Selection of a Single-Stranded DNA Molecular Recognition Element against Atrazine

    PubMed Central

    Williams, Ryan M.; Crihfield, Cassandra L.; Gattu, Srikanth; Holland, Lisa A.; Sooter, Letha J.

    2014-01-01

    Widespread use of the chlorotriazine herbicide, atrazine, has led to serious environmental and human health consequences. Current methods of detecting atrazine contamination are neither rapid nor cost-effective. In this work, atrazine-specific single-stranded DNA (ssDNA) molecular recognition elements (MRE) were isolated. We utilized a stringent Systematic Evolution of Ligands by Exponential Enrichment (SELEX) methodology that placed the greatest emphasis on what the MRE should not bind to. After twelve rounds of SELEX, an atrazine-specific MRE with high affinity was obtained. The equilibrium dissociation constant (Kd) of the ssDNA sequence is 0.62 ± 0.21 nM. It also has significant selectivity for atrazine over atrazine metabolites and other pesticides found in environmentally similar locations and concentrations. Furthermore, we have detected environmentally relevant atrazine concentrations in river water using this MRE. The strong affinity and selectivity of the selected atrazine-specific ssDNA validated the stringent SELEX methodology and identified a MRE that will be useful for rapid atrazine detection in environmental samples. PMID:25196435

  2. Fabrication of an atrazine acoustic immunosensor based on a drop-deposition procedure.

    PubMed

    Jia, Kun; Toury, Timothée; Ionescu, Rodica Elena

    2012-09-01

    Among the various novel analytical systems, immunosensors based on acoustic waves are of emerging interest because of their good sensitivity, real-time monitoring capability, and experimental simplicity. In this work, piezoelectric immunosensors were constructed for the detection of atrazine through the immobilization of specific monoclonal anti-atrazine antibodies on thiolated modified quartz crystal microbalances (QCMs). The immunoassay was conducted by a novel drop-deposition procedure using different atrazine dilutions in phosphate buffer solution ranging from 10(-10) to 10(-1) mg/mL. The immunoreactions between varying contents of atrazine and its antibody were dynamically exhibited through in situ monitoring of the frequency and motional resistance changes over 20 min. Thus, atrazine recognition by the anti-atrazine antibody leads to a decrease of the resonant frequency that is proportional to a given atrazine concentration. Interestingly, the motional resistance also increased proportionally during the measurements, which could be attributed to the specific viscoelastic properties and/or conformation changes of the antibodies once the immunoreactions occurred. By combining the measurements of frequency with those of motional resistance, additional information was provided about the interaction between the atrazine-named antigen and its respective antibody. Finally, the analytical specificity of the immunosensor to atrazine was evaluated through the response to a nonspecific anti-human IgG antibody-modified QCM crystal under the same drop conditions.

  3. [Effect of acid rain, copper, and atrazine on soil hydrolase activity].

    PubMed

    Liu, Guangshen; Xu, Dongmei; Li, Kebin; Liu, Weiping

    2004-01-01

    The effects of acid rain, Cu2+ and atrazine on the activities of soil urease, invertase and acid phosphatase were studied by means of orthogonal test. The results showed that the inhibition rate was H+ > Cu2+, and atrazine had no significant influence on urease and intertase. Interaction analysis revealed that Cu x atrazine exhibited synergism on soil acid phosphatase activity, Cu x H had antagonism on soil invertase and urease, but atrazine x H had no interaction within the investigated concentration range. Among the three enzymes, soil acid phosphatase was the most sensitive one to the contaminations.

  4. Isolation and characterization of atrazine mineralizing Bacillus subtilis strain HB-6.

    PubMed

    Wang, Jinhua; Zhu, Lusheng; Wang, Qi; Wang, Jun; Xie, Hui

    2014-01-01

    Atrazine is a widely used herbicide with great environmental concern due to its high potential to contaminate soil and waters. An atrazine-degrading bacterial strain HB-6 was isolated from industrial wastewater and the 16S rRNA gene sequencing identified HB-6 as a Bacillus subtilis. PCR assays indicated that HB-6 contained atrazine-degrading genes trzN, atzB and atzC. The strain HB-6 was capable of utilizing atrazine and cyanuric acid as a sole nitrogen source for growth and even cleaved the s-triazine ring and mineralized atrazine. The strain demonstrated a very high efficiency of atrazine biodegradation with a broad optimum pH and temperature ranges and could be enhanced by cooperating with other bacteria, suggesting its huge potential for remediation of atrazine-contaminated sites. To our knowledge, there are few Bacillus subtilis strains reported that can mineralize atrazine, therefore, the present work might provide some new insights on atrazine remediation.

  5. Nanoencapsulation Enhances the Post-Emergence Herbicidal Activity of Atrazine against Mustard Plants.

    PubMed

    Oliveira, Halley Caixeta; Stolf-Moreira, Renata; Martinez, Cláudia Bueno Reis; Grillo, Renato; de Jesus, Marcelo Bispo; Fraceto, Leonardo Fernandes

    2015-01-01

    Poly(epsilon-caprolactone) (PCL) nanocapsules have been recently developed as a modified release system for atrazine, an herbicide that can have harmful effects in the environment. Here, the post-emergence herbicidal activity of PCL nanocapsules containing atrazine was evaluated using mustard (Brassica juncea) as target plant species model. Characterization of atrazine-loaded PCL nanocapsules by nanoparticle tracking analysis indicated a concentration of 7.5 x 10(12) particles mL(-1) and an average size distribution of 240.7 nm. The treatment of mustard plants with nanocapsules carrying atrazine at 1 mg mL(-1) resulted in a decrease of net photosynthesis and PSII maximum quantum yield, and an increase of leaf lipid peroxidation, leading to shoot growth inhibition and the development of severe symptoms. Time course analysis until 72 h after treatments showed that nanoencapsulation of atrazine enhanced the herbicidal activity in comparison with a commercial atrazine formulation. In contrast to the commercial formulation, ten-fold dilution of the atrazine-containing nanocapsules did not compromise the herbicidal activity. No effects were observed when plants were treated with nanocapsules without herbicide compared to control leaves sprayed with water. Overall, these results demonstrated that atrazine-containing PCL nanocapsules provide very effective post-emergence herbicidal activity. More importantly, the use of nanoencapsulated atrazine enables the application of lower dosages of the herbicide, without any loss of efficiency, which could provide environmental benefits.

  6. In vitro selection of a single-stranded DNA molecular recognition element against atrazine.

    PubMed

    Williams, Ryan M; Crihfield, Cassandra L; Gattu, Srikanth; Holland, Lisa A; Sooter, Letha J

    2014-08-18

    Widespread use of the chlorotriazine herbicide, atrazine, has led to serious environmental and human health consequences. Current methods of detecting atrazine contamination are neither rapid nor cost-effective. In this work, atrazine-specific single-stranded DNA (ssDNA) molecular recognition elements (MRE) were isolated. We utilized a stringent Systematic Evolution of Ligands by Exponential Enrichment (SELEX) methodology that placed the greatest emphasis on what the MRE should not bind to. After twelve rounds of SELEX, an atrazine-specific MRE with high affinity was obtained. The equilibrium dissociation constant (Kd) of the ssDNA sequence is 0.62 ± 0.21 nM. It also has significant selectivity for atrazine over atrazine metabolites and other pesticides found in environmentally similar locations and concentrations. Furthermore, we have detected environmentally relevant atrazine concentrations in river water using this MRE. The strong affinity and selectivity of the selected atrazine-specific ssDNA validated the stringent SELEX methodology and identified a MRE that will be useful for rapid atrazine detection in environmental samples.

  7. Atrazine and its degradates have little effect on the corticosteroid stress response in the zebrafish.

    PubMed

    Van Der Kraak, Glen; Matsumoto, Jacquie; Kim, Myoungwoo; Hosmer, Alan J

    2015-04-01

    The present study examined the effects of atrazine on basal and forced swimming induced changes in whole body cortisol content in adult zebrafish. Zebrafish were exposed to graded concentrations of atrazine or the atrazine degradates deisopropylatrazine (DIA), deethylatrazine (DEA) and diamino-s-chlorotriazine (DACT) for up to 10 days. Some fish were sampled for the measurement of whole body cortisol levels under basal conditions while others were sampled after being subjected to a 20 min swimming challenge in order to quantify stress induced cortisol levels. In one experiment, zebrafish were subjected to two bouts of forced swimming 3h apart to test whether prior atrazine exposure affects the ability of the fish to respond appropriately to a repeated stressor. The results demonstrated that controls not exposed to atrazine and zebrafish exposed to atrazine or the atrazine degradates at nominal concentrations of up to 100 μg/L consistently exhibited increased whole body cortisol content in response to the swimming challenge. Separate analyses revealed few changes in basal or stress induced cortisol levels following atrazine exposure. Overall, these data suggest that atrazine and some of its degradates at the concentrations tested have minimal effects on the cortisol mediated stress response in the zebrafish.

  8. Atrazine and glyphosate dynamics in a lotic ecosystem: the common snapping turtle as a sentinel species.

    PubMed

    Douros, Derrick L; Gaines, Karen F; Novak, James M

    2015-03-01

    Atrazine and glyphosate are two of the most common pesticides used in the US Midwest that impact water quality via runoff, and the common snapping turtle (Chelydra serpentina) is an excellent indicator species to monitor these pesticides especially in lotic systems. The goals of this study were to (1) quantify atrazine, the atrazine metabolite diaminochlorotriazine (DACT), and glyphosate burdens in common snapping turtle tissue from individuals collected within the Embarras River in Illinois; (2) quantify atrazine, DACT, and glyphosate loads in water from the aquatic habitats in which common snapping turtles reside; and (3) investigate tissue loads based on turtle morphology and habitat choice. Concentrations of atrazine, DACT, and glyphosate in tissue did not show any relationship with lake habitat, carapace length, width, or mass. Both atrazine and glyphosate tissue samples varied as a function of site (river vs. lake), but DACT did not. Atrazine and glyphosate concentrations in water samples showed a linear effect on distance from the reservoir spillway and a deviation from linearity. Water column concentrations of all three contaminants varied across capture sites, but atrazine water concentration did not influence DACT water concentration nor did it exhibit a site interaction. Water atrazine and glyphosate concentrations were greater than tissue concentrations, whereas DACT water and tissue concentrations did not differ. This study showed that turtles are useful in long-term pesticide monitoring, and because DACT as a metabolite is less sensitive to variation, it should be considered as a preferred biomarker for pesticide runoff.

  9. Effects of atrazine on embryos, larvae, and adults of anuran amphibians.

    PubMed

    Allran, J W; Karasov, W H

    2001-04-01

    We examined the effects of atrazine (0-20 mg/L) on embryos, larvae, and adult anuran amphibian species in the laboratory. Atrazine treatments did not affect hatchability of embryos or 96-h posthatch mortality of larvae of Rana pipiens, Rana sylvatica, or Bufo americanus. Furthermore, atrazine had no effect on swimming speed (measured for R. pipiens only). However, there was a dose-dependent increase in deformed larvae of all three species with increasing atrazine concentration. In adult R. pipiens, atrazine increased buccal and thoracic ventilation, indicating respiratory distress. However, because atrazine had no affect on hemoglobin, this respiratory distress was probably not indicative of reduced oxygen-carrying capacity of the blood. Frogs exposed to the highest atrazine concentration stopped eating immediately after treatment began and did not eat during the 14-d experiment. However, no decreases in mass were measured even for frogs that were not eating, probably because of compensatory fluid gain from edema. Atrazine concentrations found to be deleterious to amphibian embryos and adults are considerably higher than concentrations currently found in surface waters in North America. Therefore, direct toxicity of atrazine is probably not a significant factor in recent amphibian declines.

  10. Isolation and Characterization of Atrazine Mineralizing Bacillus subtilis Strain HB-6

    PubMed Central

    Wang, Jinhua; Zhu, Lusheng; Wang, Qi; Wang, Jun; Xie, Hui

    2014-01-01

    Atrazine is a widely used herbicide with great environmental concern due to its high potential to contaminate soil and waters. An atrazine-degrading bacterial strain HB-6 was isolated from industrial wastewater and the 16S rRNA gene sequencing identified HB-6 as a Bacillus subtilis. PCR assays indicated that HB-6 contained atrazine-degrading genes trzN, atzB and atzC. The strain HB-6 was capable of utilizing atrazine and cyanuric acid as a sole nitrogen source for growth and even cleaved the s-triazine ring and mineralized atrazine. The strain demonstrated a very high efficiency of atrazine biodegradation with a broad optimum pH and temperature ranges and could be enhanced by cooperating with other bacteria, suggesting its huge potential for remediation of atrazine-contaminated sites. To our knowledge, there are few Bacillus subtilis strains reported that can mineralize atrazine, therefore, the present work might provide some new insights on atrazine remediation. PMID:25238246

  11. Degradation of atrazine in soil through induced photocatalytic processes

    SciTech Connect

    Pelizzetti, E. ); Carlin, V.; Maurino, V.; Minero, C.; Dolci, M. ); Marchesini, A. )

    1990-08-01

    The authors observed photocatalytic degradation of atrazine in the presence of semiconductor metal oxide particulates (TiO{sub 2}, ZnO) suspended in aqueous solution under simulated sunlight irradiation. The half-life for the process is ca. 5 and 80 min for TiO{sub 2} and ZnO, respectively (at an initial atrazine concentration of 25 mg/liter with 0.5 g of semiconductor per liter and with a photon flux of 3 {times} 10{sup {minus}5} einstein/min, and over a cell cross section of 4 cm{sup 2}). The authors investigated the catalytic activity of different soils. The weak photocatalytic activity of the soils (2 g/liter) is dramatically increased by the addition of 0.5 g of the semiconductor per liter. Half-lives are 10 to 40 minutes, depending on the nature of the soil.

  12. Recovery of duckweed from time-varying exposure to atrazine.

    PubMed

    Brain, Richard A; Hosmer, Alan J; Desjardins, Debbie; Kendall, Timothy Z; Krueger, Henry O; Wall, Steven B

    2012-05-01

    The purpose of the present study was to evaluate the recovery of duckweed (Lemna gibba L. G3) after being removed from multiple duration exposures to the herbicide atrazine. Consequently, L. gibba were exposed under various scenarios to atrazine at nominal concentrations ranging from 5 to 160 µg/L and durations of 1, 3, 5, 7, 9, and 14 d under static-renewal test conditions. Exposures were followed by a recovery phase in untreated media for either 7 or 14 d. The 3-, 5-, 7-, 9-, and 14-d median effective concentration (EC50) values were >137, >137, 124, >77, and >75 µg/L, respectively, based on mean growth rate. No clear effect trends were apparent between exposure duration and the magnitude of effective concentrations (EC50s or EC10s). No phytocidal effects of chlorosis or necrosis were identified for any treatment scenario. Nearly all L. gibba plants transferred from treatment groups of different exposure scenarios to media without atrazine during the recovery phase had growth rates that demonstrated immediate recovery, indicating effects were phytostatic in nature and reversible. Only the 1- and 5-d exposure scenarios had growth rates indicating marginally prolonged recovery at the higher concentrations (160 µg/L; additionally, at 40 µg/L for the 5-d exposure). Time to recovery, therefore, was found to be largely independent of exposure duration except at the highest concentrations assessed. Based on growth rate by interval, all treatments demonstrated recovery by the final assessment interval (days 5-7), indicating complete recovery in all exposure scenarios by 7 d, consistent with the mode of action of atrazine. PMID:22431202

  13. Recovery of duckweed from time-varying exposure to atrazine.

    PubMed

    Brain, Richard A; Hosmer, Alan J; Desjardins, Debbie; Kendall, Timothy Z; Krueger, Henry O; Wall, Steven B

    2012-05-01

    The purpose of the present study was to evaluate the recovery of duckweed (Lemna gibba L. G3) after being removed from multiple duration exposures to the herbicide atrazine. Consequently, L. gibba were exposed under various scenarios to atrazine at nominal concentrations ranging from 5 to 160 µg/L and durations of 1, 3, 5, 7, 9, and 14 d under static-renewal test conditions. Exposures were followed by a recovery phase in untreated media for either 7 or 14 d. The 3-, 5-, 7-, 9-, and 14-d median effective concentration (EC50) values were >137, >137, 124, >77, and >75 µg/L, respectively, based on mean growth rate. No clear effect trends were apparent between exposure duration and the magnitude of effective concentrations (EC50s or EC10s). No phytocidal effects of chlorosis or necrosis were identified for any treatment scenario. Nearly all L. gibba plants transferred from treatment groups of different exposure scenarios to media without atrazine during the recovery phase had growth rates that demonstrated immediate recovery, indicating effects were phytostatic in nature and reversible. Only the 1- and 5-d exposure scenarios had growth rates indicating marginally prolonged recovery at the higher concentrations (160 µg/L; additionally, at 40 µg/L for the 5-d exposure). Time to recovery, therefore, was found to be largely independent of exposure duration except at the highest concentrations assessed. Based on growth rate by interval, all treatments demonstrated recovery by the final assessment interval (days 5-7), indicating complete recovery in all exposure scenarios by 7 d, consistent with the mode of action of atrazine.

  14. Detection of DNA damage by alkaline single cell gel electrophoresis in 2,4-dichlorophenoxyacetic-acid- and butachlor-exposed erythrocytes of Clarias batrachus.

    PubMed

    Ateeq, Bushra; Abul Farah, M; Ahmad, Waseem

    2005-11-01

    The alkaline single cell gel electrophoresis, also known as comet assay, is a rapid, simple and sensitive technique for measuring DNA strand breaks in individual cells. The present study was undertaken to evaluate the genotoxic potential of two widely used herbicides; 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-chloro-2,6-diethyl-N-(butoxymethyl) acetanilide (butachlor) in erythrocytes of freshwater catfish, Clarias batrachus. Fish were exposed by medium treatment with three sub-lethal concentrations of 2,4-D (25, 50, and 75ppm) and butachlor (1, 2, and 2.5ppm) and alkaline comet assay was performed on nucleated erythrocytes after 48, 72, and 96h. The amount of DNA damage in cells was estimated from comet tail length as the extent of migration of the genetic material. A significant increase in comet tail length indicating DNA damage was observed at all concentrations of both the herbicides compared with control (P<0.05). The mean comet tail length showed a concentration-related and time-dependent increase as the maximum tail length recorded at highest concentration and longer duration of 2,4-D (9.59microm) and butachlor (9.28microm). This study confirmed that the comet assay applied on the fish erythrocyte is a useful tool in determining potential genotoxicity of water pollutants and might be appropriate as a part of a monitoring program.

  15. POTENTIAL ROLE OF TUBERO-INFUNDIBULAR DOPAMINERGIC NEURONS IN THE DISRUPTION OF PITUITARY HORMONE SECRETION BY ATRAZINE

    EPA Science Inventory

    Previously, we demonstrated that atrazine suppressed the ovulatory surge of luteininzing hormone and disrupted estrous cycles in the female rat. We also reported that this disruption of ovulation is likely the result of atrazine's effect on hypothalamic gonadotropin hormone rele...

  16. PRELIMINARY OBSERVATIONS OF ATRAZINE-INDUCED EFFECTS UPON GONADAL DIFFERENTIATION IN RIVULUS MARMORATUS, A NATURALLY HERMAPHRODITIC FISH

    EPA Science Inventory

    The commonly used agricultural herbicide atrazine has been recognized as an endocrine disrupting chemical. In amphibians and reptiles, atrazine has been reported to alter sexual differentiation and induce secondary sexual characteristics that have been attributed to enhanced arom...

  17. Polyelectrolytes Ability in Reducing Atrazine Concentration in Water: Surface Effects

    PubMed Central

    Heijman, S. G. J.; Lopes, S. I. C.; Rietveld, L. C.

    2014-01-01

    This paper reports on the direct ability of two positively charged organic polyelectrolytes (natural-based and synthetic) to reduce the atrazine concentration in water. The adsorption study was set up using multiple glass vessels with different polymer dosing levels followed by ultrafiltration with a 1 kDa membrane. The addition of polymers exhibited a capability in reducing the atrazine concentration up to a maximum of 60% in surface-to-volume ratio experiments. In the beginning, the theoretical L-type of the isotherm of Giles' classification was expected with an increase in the dosage of the polymer. However, in this study, the conventional type of isotherm was not observed. It was found that the adsorption of the cationic polymer on the negatively charged glass surface was necessary and influential for the removal of atrazine. Surface-to-volume ratio adsorption experiments were performed to elucidate the mechanisms and the polymer configuration. The glass surface area was determined to be a limiting parameter in the adsorption mechanism. PMID:25197693

  18. Effects of carbon nanotubes on atrazine biodegradation by Arthrobacter sp.

    PubMed

    Zhang, Chengdong; Li, Mingzhu; Xu, Xu; Liu, Na

    2015-04-28

    The environmental risks of engineered nanoparticles have attracted attention. However, little is known regarding the effects of carbon nanotubes (CNTs) on the biodegradation and persistence of organic contaminants in water. We investigated the impacts of pristine and oxidized multiwalled CNTs on the atrazine biodegradation rate and efficiency using Arthrobacter sp. At a concentration of 25mg/L, the CNTs enhanced the biodegradation rate by up to 20%; however, at a concentration of 100mg/L, the CNTs decreased the biodegradation rate by up to 50%. The stimulation effects resulted from enhanced bacterial growth and the overexpression of degradation genes. The inhibitory effects resulted from the toxicity of the CNTs at high concentrations. The differences between the two CNTs at tested concentrations were not significant. The biodegradation efficiency was not impacted by adsorption, and the pre-adsorbed atrazine on the CNTs was fully biodegraded when the CNT concentration was ≤25mg/L. This finding was consistent with the lack of observable desorption hysteresis for atrazine on the tested CNTs. Our results indicate that CNTs can enhance or inhibit biodegradation through a balance of two effects: the toxic effects on microbial activity and the effects of the changing bioavailability that result from adsorption and desorption.

  19. Atrazine and total triazines: Exposure patterns in midwestern surface waters

    SciTech Connect

    Richards, R.P.; Baker, D.B.

    1996-10-01

    Distributions of atrazine and total triazine exposures for aquatic organisms in the midwestern United States and Canada were characterized using the most complete datasets available, with attention to the sampling pattern used in obtaining the data. Distributions were established form stantaneous concentrations and for 96-hour and 21-day running averages. Time weighting and annualization were important to avoid distorted estimates of exposure concentrations; failure to use appropriate procedures can lead to order-of-magnitude errors in estimates of benchmarks such as the 90th percentile concentration. Atrazine and total triazine concentrations are characterized by strong seasonality, with elevated concentrations for a period of 6 to 10 weeks following application in May or June. Concentrations decline during July, August, and September, and for the rest of the year are near detection limit. Concentrations in running water are strongly influenced by storm runoff, with much higher concentrations during run off than during low-flow periods between run off events. Thus aquatic organisms in running waters experience pulsed exposures interspersed with recovery periods. 90th percentile concentrations were calculated for a number of rivers, streams, lakes, and reservoirs for comparison with ecological effects data. Total triazine concentrations are only slightly higher than atrazine concentrations in those waters for which comparisons were possible.

  20. [Isolation, identification and characterization of an atrazine degrading bacterium].

    PubMed

    Li, Shao-Feng; Zhu, Jing; Li, Tie-Jing

    2012-09-01

    An atrazine-degrading bacterial strain named L-6 was isolated from the sludge mixture of the sewage treatment plant by cultivating in raw water with limited nutrition and aeration and was domesticated steadily using SBR (Sequencing Batch Reactor) for two months. The degradation rate of atrazine in inorganic liquid culture medium with atrazine as the sole source of nitrogen could reach 89.2% after 96 hours. The cells showed shape of long rod under scanning electron microscope. After extraction of genomic DNA and PCR amplification, the 16S rRNA gene sequences were used for homology analysis and construction of phylogenetic trees. The results suggested that the 16S rRNA gene sequence of L-6 had up to 99% homology with those of many strains of Pseudomonas strains in GenBank database. With physiological and biochemical reactions, the strain L-6 was identified as Pseudomonas sp. Carbon use test indicated that L-6 can utilize glucose, fructose and citric acid sodium as carbon sources, but could not use sucrose, lactose or starch. The optimum degradation conditions were optimized as following:temperature 30 degrees C, initial pH 7-9.

  1. [Experimental research on bioremediation of groundwater contaminated by herbicide atrazine].

    PubMed

    Hu, Hongtao; Lin, Xueyu; Lu, Yongsen

    2003-11-01

    The experimental research on the static degradation and treatment of groundwater contaminated by herbicide atrazine was conducted by using bacterium AT which was isolated from the sludge outlet of workshop of the pesticide factory. And the result indicated that bacterium AT had the ability of degradation of atrazine with pH ranged from 5.0 to 10.0, and the optimum extent was 6.5-8.0. The experimental conditions (pH = 7.5, t = 10 degrees C) were similar to that of the aquifer in study area. Then the rate of degradation of atrazine was up to 31.08% for one addition of bacterium AT. And the environmental factors changed simultaneously in the course of experiment such as DO, pH and etc. decreasing with the reducing of concentration of bacterium AT. In addition, a mode of dropping bacteria was designed to simulate the condition of throwing bacteria in field. And the permeability of aquifer decreased 60.54% after treatment and the renewals were 48.96% after washing with clean water for 10 days, which indicated the method of renewal is effectual.

  2. Polyelectrolytes ability in reducing atrazine concentration in water: surface effects.

    PubMed

    Mohd Amin, Mohamad Faiz; Heijman, S G J; Lopes, S I C; Rietveld, L C

    2014-01-01

    This paper reports on the direct ability of two positively charged organic polyelectrolytes (natural-based and synthetic) to reduce the atrazine concentration in water. The adsorption study was set up using multiple glass vessels with different polymer dosing levels followed by ultrafiltration with a 1 kDa membrane. The addition of polymers exhibited a capability in reducing the atrazine concentration up to a maximum of 60% in surface-to-volume ratio experiments. In the beginning, the theoretical L-type of the isotherm of Giles' classification was expected with an increase in the dosage of the polymer. However, in this study, the conventional type of isotherm was not observed. It was found that the adsorption of the cationic polymer on the negatively charged glass surface was necessary and influential for the removal of atrazine. Surface-to-volume ratio adsorption experiments were performed to elucidate the mechanisms and the polymer configuration. The glass surface area was determined to be a limiting parameter in the adsorption mechanism. PMID:25197693

  3. In vitro atrazine exposure affects the phenotypic and functional maturation of dendritic cells

    SciTech Connect

    Pinchuk, Lesya M.; Lee, Sang-Ryul; Filipov, Nikolay M.

    2007-09-15

    Recent data suggest that some of the immunotoxic effects of the herbicide atrazine, a very widely used pesticide, may be due to perturbations in dendritic cell (DC) function. As consequences of atrazine exposure on the phenotypic and functional maturation of DC have not been studied, our objective was, using the murine DC line, JAWSII, to determine whether atrazine will interfere with DC maturation. First, we characterized the maturation of JAWSII cells in vitro by inducing them to mature in the presence of growth factors and selected maturational stimuli in vitro. Next, we exposed the DC cell line to a concentration range of atrazine and examined its effects on phenotypic and functional maturation of DC. Atrazine exposure interfered with the phenotypic and functional maturation of DC at non-cytotoxic concentrations. Among the phenotypic changes caused by atrazine exposure was a dose-dependent removal of surface MHC-I with a significant decrease being observed at 1 {mu}M concentration. In addition, atrazine exposure decreased the expression of the costimulatory molecule CD86 and it downregulated the expression of the CD11b and CD11c accessory molecules and the myeloid developmental marker CD14. When, for comparative purposes, we exposed primary thymic DC to atrazine, MHC-I and CD11c expression was also decreased. Phenotypic changes in JAWSII DC maturation were associated with functional inhibition of maturation as, albeit at higher concentrations, receptor-mediated antigen uptake was increased by atrazine. Thus, our data suggest that atrazine directly targets DC maturation and that toxicants such as atrazine that efficiently remove MHC-I molecules from the DC surface are likely to contribute to immune evasion.

  4. Cloning and expression of an atrazine inducible cytochrome P450 from Chironomus tentans (Diptera: Chironomidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies performed in our lab have measured the effect of atrazine exposure on cytochrome P450-dependent monooxygenase activity and have found increased activity in midge larvae (Chironomus tentans) as a result of atrazine exposure (1-10 ppm). Here we report the cloning and expression of a ...

  5. EFFECTS OF ATRAZINE ON THE REPRODUCTIVE SUCCESS IN THE MARINE FISH, CUNNER(TAUTOGOLABRUS ADSPERSUS)

    EPA Science Inventory

    Atrazine, the most widely used herbicide in the world, leaches into ground water and surface runoff after agricultural and forestry applications. It has been detected in concentrations in the ppb range in ground water, surface waters, rivers, streams, and precipitation. Atrazin...

  6. Conservation program (EQIP) reduces atrazine in Columbus, OH drinking water supply reservoir

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation dollars applied in the Upper Big Walnut Creek Watershed have achieved a significant reduction in the atrazine levels in Hover Reservoir, a major drinking water source for Columbus, Ohio. During the 1990s, atrazine levels in this reservoir periodically exceeded the health advisory limit ...

  7. Effect of compost age and composition on the atrazine removal from solution

    USGS Publications Warehouse

    Tsui, L.; Roy, W.R.

    2007-01-01

    Compost samples from two composting facilities, the Urbana (Illinois) Landscape Recycling Center (ULRC) and Illinois State University (ISU), were selected to examine the effect of compost age on atrazine removal from solution. The ULRC samples were made from yard waste without an additional nitrogen source. The ISU samples were made from yard waste or sawdust with the addition of manure. The 6-month-old ULRC compost had the greater capacity to remove atrazine from solution, which we attributed to its greater organic carbon content. The addition of nitrate into ULRC compost could influence the extent of atrazine removal, but did not have a significant impact on atrazine removal when applied to ISU compost, probably because manure was added to the yard waste to produce the compost. For both ULRC and ISU samples, the presence of sodium azide inhibited atrazine removal, suggesting that microbial activity contributed to the atrazine removal. Metabolic analysis demonstrated that hydroxyatrazine was the major identified metabolite that accumulated in solution before significant ring mineralization could occur. When compared with the ISU compost, the ULRC compost sample had a greater capacity to remove atrazine from solution during the 120 days of study because of the larger humic acid content. The experimental results suggested that less-mature compost may be better suited for environmental applications such as removing atrazine from tile-drainage waters. ?? 2006 Elsevier B.V. All rights reserved.

  8. Response of ligninolytic macrofungi to the herbicide atrazine: dose-response bioassays.

    PubMed

    Cupul, Wilberth Chan; Abarca, Gabriela Heredia; Vázquez, Refugio Rodríguez; Salmones, Dulce; Hernández, Rigoberto Gaitán; Gutiérrez, Enrique Alarcón

    2014-01-01

    The effect of atrazine concentrations on mycelial growth and ligninolytic enzyme activities of eight native ligninolytic macrofungi isolated in Veracruz, México, were evaluated in a semi-solid culture medium. Inhibition of mycelial growth and growth rates were significantly affected (p=0.05) by atrazine concentrations (468, 937, 1875, and 3750 mg/l). In accordance with the median effective concentration (EC50), Pleurotus sp. strain 1 proved to be the most tolerant isolate to atrazine (EC50=2281.0 mg/l), although its enzyme activity was not the highest. Pycnoporus sanguineus strain 2, Daedalea elegans and Trametes maxima showed high laccase activity (62.7, 31.9, 29.3 U mg/protein, respectively) without atrazine (control); however, this activity significantly increased (p<0.05) (to 191.1, 83.5 and 120.6 U mg/protein, respectively) owing to the effect of atrazine (937 mg/l) in the culture medium. Pleurotus sp. strain 2 and Cymatoderma elegans significantly increased (p<0.05) their manganese peroxidase (MnP) activities under atrazine stress at 468 mg/l. The isolates with high EC50 (Pleurotus sp. strain 1) and high enzymatic activity (P. sanguineus strain 2 and T. maxima) could be considered for future studies on atrazine mycodegradation. Furthermore, this study confirms that atrazine can increase laccase and MnP activities in ligninolytic macrofungi.

  9. THE EFFECTS OF ATRAZINE METABOLITES ON PUBERTY IN THE MALE WISTAR RAT

    EPA Science Inventory

    The Effects of Atrazine Metabolites on Puberty in the Male Wistar Rat. D L Guidici, R L Cooper and T E Stoker. Endocrinology Branch, NHEERL, U.S. Environmental Protection Agency, RTP, NC.
    Sponsor: R J Kavlock.
    Atrazine (ATR), a chlorotriazine herbicide, alters pubertal pr...

  10. Effects of sublethal concentrations of atrazine and nitrate on metamorphosis of the African clawed frog.

    PubMed

    Sullivan, Karen Brown; Spence, Karla M

    2003-03-01

    Tadpoles of the African clawed frog (Xenopus laevis) were exposed to sublethal concentrations of atrazine (0, 40, and 320 microg/L) and nitrate (0, 37, and 292 mg/L) from feeding stage to metamorphosis. A 3 x 3 factorial design was used to identify both single and interactive effects. At metamorphosis, tadpole weight, snout-vent length (SVL), and hematocrit were determined. Mean mortality was greater in tanks receiving 320 microg/L atrazine; nitrate had no effect on mortality. Significant differences for all mean traits at metamorphosis occurred among atrazine treatments; higher atrazine exposure increased time to metamorphosis and decreased weight, SVL, and hematocrit. Nitrate treatments were not significantly different. Significant interaction tests between atrazine and nitrate occurred for weight and SVL at metamorphosis; the specific type of interaction varied among treatments. Assuming an additive mixture model, at low atrazine (40 microg/L), the addition of 37 mg/L nitrate produced SVL values less than expected (a synergistic effect) while the addition of 292 mg/L nitrate yielded SVL values greater than expected (an antagonistic effect). A similar response was noted for tadpoles in the 320-microg/L atrazine treatments. These results indicate that environmentally realistic concentrations of atrazine exert a negative impact on amphibian metamorphosis. Also, this study suggests that mixtures of agricultural chemicals, even if sublethal, may exert negative and not necessarily consistent mixture effects.

  11. 76 FR 56754 - Petition Requesting Ban on Use and Production of Atrazine; Notice of Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-14

    ... the environmental advocacy group Save the Frogs that EPA ban the use and production of atrazine. DATES... environmental advocacy group Save the Frogs requesting that EPA ban the use and production of atrazine. This... Frogs founder Dr. Kerry Kriger. The presentation and participant list from the meeting is also...

  12. Atrazine retention and degradation in the vadose zone at a till plain site in central Indiana

    USGS Publications Warehouse

    Bayless, E.R.

    2001-01-01

    The vadose zone was examined as an environmental compartment where significant quantities of atrazine and its degradation compounds may be stored and transformed. The vadose zone was targeted because regional studies in the White River Basin indicated a large discrepancy between the mass of atrazine applied to fields and the amount of the pesticide and its degradation compounds that are measured in ground and surface water. A study site was established in a rotationally cropped field in the till plain of central Indiana. Data were gathered during the 1994 growing season to characterize the site hydrogeology and the distribution of atrazine, desethylatrazine, deisopropylatrazine, didealkylatrazine and hydroxyatrazine in runoff, pore water, and ground water. The data indicated that atrazine and its degradation compounds were transported from land surface to a depth of 1.5 m within 60 days of application, but were undetected in the saturated zone at nearby monitoring wells. A numerical model was developed, based on the field data, to provide information about processes that could retain and degrade atrazine in the vadose zone. Simulations indicated that evapotranspiration is responsible for surface directed soil-moisture flow during much of the growing season. This process causes retention and degradation of atrazine in the vadose zone. Increased residence time in the vadose zone leads to nearly complete transformation of atrazine and its degradation products to unquantified degradation compounds. As a result of mascropore flow, small quantities of atrazine and its degradation compounds may reach the saturated zone.

  13. Atrazine fate and transport within the coastal zone in southeastern Puerto Rico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbicide transport from crop-land to coastal waters may adversely impact water quality. This work examined potential atrazine impact from use on a farm field adjacent to the Jobos Bay National Estuarine Research Reserve on Puerto Rico’s southeastern coast. Atrazine application was linked to residu...

  14. Response of ligninolytic macrofungi to the herbicide atrazine: dose-response bioassays.

    PubMed

    Cupul, Wilberth Chan; Abarca, Gabriela Heredia; Vázquez, Refugio Rodríguez; Salmones, Dulce; Hernández, Rigoberto Gaitán; Gutiérrez, Enrique Alarcón

    2014-01-01

    The effect of atrazine concentrations on mycelial growth and ligninolytic enzyme activities of eight native ligninolytic macrofungi isolated in Veracruz, México, were evaluated in a semi-solid culture medium. Inhibition of mycelial growth and growth rates were significantly affected (p=0.05) by atrazine concentrations (468, 937, 1875, and 3750 mg/l). In accordance with the median effective concentration (EC50), Pleurotus sp. strain 1 proved to be the most tolerant isolate to atrazine (EC50=2281.0 mg/l), although its enzyme activity was not the highest. Pycnoporus sanguineus strain 2, Daedalea elegans and Trametes maxima showed high laccase activity (62.7, 31.9, 29.3 U mg/protein, respectively) without atrazine (control); however, this activity significantly increased (p<0.05) (to 191.1, 83.5 and 120.6 U mg/protein, respectively) owing to the effect of atrazine (937 mg/l) in the culture medium. Pleurotus sp. strain 2 and Cymatoderma elegans significantly increased (p<0.05) their manganese peroxidase (MnP) activities under atrazine stress at 468 mg/l. The isolates with high EC50 (Pleurotus sp. strain 1) and high enzymatic activity (P. sanguineus strain 2 and T. maxima) could be considered for future studies on atrazine mycodegradation. Furthermore, this study confirms that atrazine can increase laccase and MnP activities in ligninolytic macrofungi. PMID:25576420

  15. Simulations of Flow Circulations and Atrazine Concentrations in a Midwest U.S. Reservoir

    NASA Astrophysics Data System (ADS)

    Zhao, Xianggui; Gu, Roy R.; Guo, Chuling; Wang, Kui; Li, Shijie

    Atrazine is the most commonly used herbicide in the spring for pre-emergent weed control in the corn cropping area in the Midwestern United States. A frequent high level of herbicide concentrations in reservoirs is a great concern for public health and aquatic ecosystems. In this study, a two-dimensional hydrodynamics and toxic contaminant transport model was applied to Saylorville Reservoir, Iowa, USA. The model simulates physical, chemical, and biological processes and predicts unsteady vertical and longitudinal distributions of a toxic chemical. Model results were validated by measured temperatures and atrazine concentrations. Simulated flow velocities, water temperatures, and chemical concentrations demonstrated that the spatial variation of atrazine concentrations was largely affected by seasonal flow circulation patterns in the reservoir. In particular, the simulated fate and transport of atrazine showed the effect of flow circulation on spatial distribution of atrazine during summer months as the river flow formed an underflow within the reservoir and resulted in greater concentrations near the surface of the reservoir. Atrazine concentrations in the reservoir peaked around the end of May and early June. A thorough understanding of the fate and transport of atrazine in the reservoir can assist in developing operation and pollution prevention strategies with respect to timing, amount, and depth of withdrawal. The responses of atrazine transport to various boundary conditions provide useful information in assessing environmental impact of alternative upstream watershed management practices on the quality of reservoir water.

  16. Catalytic effect of transition metals on microwave-induced degradation of atrazine in mineral micropores.

    PubMed

    Hu, Erdan; Cheng, Hefa

    2014-06-15

    With their high catalytic activity for redox reactions, transition metal ions (Cu(2+) and Fe(3+)) were exchanged into the micropores of dealuminated Y zeolites to prepare effective microporous mineral sorbents for sorption and microwave-induced degradation of atrazine. Due to its ability to complex with atrazine, loading of copper greatly increased the sorption of atrazine. Atrazine sorption on iron-exchanged zeolites was also significantly enhanced, which was attributed to the hydrolysis of Fe(3+) polycations in mineral micropores and electrostatic interactions of protonated atrazine molecules with the negatively charged pore wall surface. Copper and iron species in the micropores also significantly accelerated degradation of the sorbed atrazine (and its degradation intermediates) under microwave irradiation. The catalytic effect was attributed to the easy reducibility and high oxidation activity of Cu(2+) and Fe(3+) species stabilized in the micropores of the zeolites. It was postulated that the surface species of transition metals (monomeric Cu(2+), Cu(2+)-O-Cu(2+) complexes, FeO(+), and dinuclear Fe-O-Fe-like species) in the mineral micropores were thermally activated under microwave irradiation, and subsequently formed highly reactive sites catalyzing oxidative degradation of atrazine. The transition metal-exchanged zeolites, particularly the iron-exchanged ones, were relatively stable when leached under acidic conditions, which suggests that they are reusable in sorption and microwave-induced degradation. These findings offer valuable insights on designing of effective mineral sorbents that can selectively uptake atrazine from aqueous solutions and catalyze its degradation under microwave irradiation.

  17. Atrazine and its metabolites degradation in mineral salts medium and soil using an enrichment culture.

    PubMed

    Kumar, Anup; Singh, Neera

    2016-03-01

    An atrazine-degrading enrichment culture was used to study degradation of atrazine metabolites viz. hydroxyatrazine, deethylatrazine, and deisopropylatrazine in mineral salts medium. Results suggested that the enrichment culture was able to degrade only hydroxyatrazine, and it was used as the sole source of carbon and nitrogen. Hydroxyatrazine degradation slowed down when sucrose and/or ammonium hydrogen phosphate were supplemented as the additional sources of carbon and nitrogen, respectively. The enrichment culture could degrade high concentrations of atrazine (up to 110 μg/mL) in mineral salts medium, and neutral pH was optimum for atrazine degradation. Further, except in an acidic soil, enrichment culture was able to degrade atrazine in three soil types having different physico-chemical properties. Raising the pH of acidic soil to neutral or alkaline enabled the enrichment culture to degrade atrazine suggesting that acidic pH inhibited atrazine-degrading ability. The study suggested that the enrichment culture can be successfully utilized to achieve complete degradation of atrazine and its persistent metabolite hydroxyatrazine in the contaminated soil and water.

  18. Microwave green synthesis of biopolymer-stabilized silver nanoparticles and their adsorption behavior for atrazine

    NASA Astrophysics Data System (ADS)

    Pal, Jolly; Deb, Manas Kanti; Sircar, Jayanta Kumar; Agnihotri, Pradeep Kumar

    2015-06-01

    The application of silver nanoparticles for the removal of atrazine has been investigated. The silver nanoparticles beads were used as an adsorbent in the present study. Silver nanoparticles were prepared in the laboratory by a microwave irradiation method. The effect of initial concentration on the removal of atrazine was studied by varying the initial concentration of atrazine from 5 to 30 ppm. It was found that the percent removal of atrazine decreases on increasing the initial atrazine concentrations. A contact time of 14 h was found to be sufficient for maximum removal and was recorded as the equilibration time. The pH 6.0 ± 0.6 for atrazine was found most favorable and at this pH the percentage removal is high at room temperature (27 °C). Batch experiments demonstrated that a 2 gm adsorbent dosage is capable of removing maximum amount of atrazine from aqueous solution. Resulting data at room temperature were analyzed by the Freundlich and Langmuir models using linearized equations. Resultant data were analyzed by pseudo-first-order and pseudo-second-order rate equations. Desorption studies were made to elucidate recovery of the adsorbate and adsorbent for the economic competitiveness of the removal system. Findings of the present study revealed that silver nanoparticles beads can be an effective adsorbent for the removal of atrazine from aqueous solution.

  19. Influence of microbial and synthetic surfactant on the biodegradation of atrazine.

    PubMed

    Singh, Anil Kumar; Cameotra, Swaranjit Singh

    2014-02-01

    The present study reports the effect of surfactants (rhamnolipids and triton X-100) on biodegradation of atrazine herbicide by strain A6, belonging to the genus Acinetobacter. The strain A6 was able to degrade nearly 80 % of the 250-ppm atrazine after 6 days of growth. The bacterium degraded atrazine by de-alkylation process. Bacterial cell surface hydrophobicity as well as atrazine solubility increased in the presence of surfactant. However, addition of surfactant to the mineral salt media reduced the rate and extent of atrazine degradation by decreasing the bioavailability of herbicide. On the contrary, addition of surfactant to atrazine-contaminated soil increased the rate and extent of biodegradation by increasing the bioavailability of herbicide. As compared to triton X-100, rhamnolipids were more efficient in enhancing microbial degradation of atrazine as a significant amount of atrazine was removed from the soil by rhamnolipids. Surfactants added for the purpose of hastening microbial degradation may have an unintended inhibitory effect on herbicide degradation depending upon contiguous condition, thus highlighting the fact that surfactant must be judiciously used in bioremediation of herbicides.

  20. Model Forecasts of Atrazine in Lake Michigan in Response to Various Sensitivity and Potential Management Scenarios

    EPA Science Inventory

    For more than forty years, the herbicide atrazine has been used on corn crops in the Lake Michigan basin to control weeds. It is usually applied to farm fields in the spring before or after the corn crop emerges. A version of the WASP4 mass balance model, LM2-Atrazine, was used...

  1. Identification of an atrazine-degrading benzoxazinoid in Eastern gamagrass (tripsacum dactyloides)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was part of a broader effort to identify and characterize promising atrazine-degrading phytochemicals in Eastern gamagrass (Tripsacum dactyloides; EG) roots for the purpose of mitigating atrazine transport from agroecosystems. The objective of this study was to isolate and identify atrazi...

  2. The capacity of switchgrass (Panicum virgatum) to degrade atrazine in a phytoremediation setting.

    PubMed

    Murphy, Ian J; Coats, Joel R

    2011-03-01

    Atrazine is a widely used herbicide in agriculture. Non-point source contamination of groundwater and drinking water may pose a significant threat to humans, wildlife, and the environment. Phytoremediation may provide a cost-effective strategy for reducing non-point source contamination of atrazine from agricultural runoff. Previous studies have shown that the rhizosphere of the native prairie grass, switchgrass (Panicum virgatum) is capable of enhancing the degradation of atrazine in soils. Biodegradation also may occur within the plant biomass; however, the extent to which this occurs has not been studied. We hypothesize that switchgrass has the capacity to degrade atrazine in vivo, in addition to the microbial biotransformation that occurs in its rhizosphere. The goals of this study were to characterize the ability of switchgrass to take up atrazine from soils, quantify the amount of biodegradation occurring in the plant, and quantify the amount of degradation occurring in the rhizosphere. Switchgrass seedlings were transplanted into autoclaved and non-autoclaved sand containing 10 µg/g atrazine in sand. Treatments were sacrificed on days 0, 3, and 7. Sand and plant tissue extracts were analyzed by gas chromatography to determine the concentration of atrazine and metabolites in sand and plant tissues. Results demonstrated that leaf biomass is capable of detoxifying atrazine, because metabolites were present in leaf material and not in the sand or root.

  3. Effects of Atrazine on Reproductive Health of Nondiabetic and Diabetic Male Rats

    PubMed Central

    Jestadi, Dinesh Babu; Phaniendra, Alugoju; Babji, Undru; Shanmuganathan, Bhavatharini

    2014-01-01

    The aim of the present study was to investigate the effects of low dose of atrazine on reproductive system of male Wistar rats. 16 rats were divided into four groups of four animals each. Group I (nondiabetic) and group III (diabetic) animals served as controls that received safflower oil (300 μL/kg bw/day), respectively. Group II (nondiabetic) and group IV (diabetic) animals received atrazine (300 μg/kg bw/day). Nonsignificant decrease in the activities of antioxidant and steroidogenic enzymes and sperm parameters suggests that atrazine did not produce any effect on reproductive system of rats. Histological findings also revealed that atrazine at a dose of 300 μg/kg bw did not produce any testicular toxic effects in nondiabetic and diabetic atrazine treated rats. Low dose of atrazine did not show reproductive toxicity in rats. To know the effects of atrazine in diabetic rats further studies have to be carried out with increased concentration of atrazine. PMID:27433493

  4. Adsorption and removal at low atrazine concentration in an MBR pilot plant.

    PubMed

    Buttiglieri, G; Migliorisi, L; Malpei, F

    2011-01-01

    Atrazine is a persistent organic pollutant and it has been widely used in agriculture and forestry in the world for more than fifty years. Atrazine shows ecotoxicity effects in aquatic ecosystems even at very low level concentrations with endocrine disruptor activity. Few studies were carried out on atrazine removal performances in drinking and waste-water by biological treatments, especially in membrane bio-reactors (MBRs). MBR technology might be more efficient than the conventional one in the removal of micro-pollutants. The fate of atrazine in wastewater treatment plants and its influence on the biomass activity was evaluated in this study. The experimental work was divided in three different phases: inhibition studies on different types of biomass (by means of microcalorimetry); adsorption studies on different sludges (conventional activated sludge (CAS) - and MBR) calculating adsorption isotherms and, finally, atrazine removal in an MBR pilot plant (simulating a treatment of atrazine and nitrate contaminated groundwater). The absence of significant inhibition was observed; higher atrazine adsorption on MBR sludge was detected for lower atrazine concentration (<50 µg L(-1)); the removal efficiency in the MBR pilot plant was lower than 25% but higher than the theoretical one (based on adsorption isotherms).

  5. THE ENDOCRINE PROFILE OF INTACT FEMALE RATS ON THE DAY OF PROESTRUS FOLLOWING EXPOSURE TO ATRAZINE

    EPA Science Inventory

    The Endocrine Profile of Intact Female Rats on the Day of Proestrus Following Exposure to Atrazine.
    RL Cooper, A Buckalew, SC Laws and TE Stoker
    Endocrinology Branch, RTD, NHEERL, ORD, U.S. EPA, RTP, NC, 27711.

    The chlorotriazine herbicide, atrazine, has been sho...

  6. DISTRIBUTION OF 14C-ATRAZINE FOLLOWING AN ACUTE LACTATIONAL EXPOSURE IN THE WISTAR RAT.

    EPA Science Inventory

    The purpose of the present study was to examine the distribution of atrazine in the lactating dam and suckling neonate following an acute exposure to either 2 or 4 mg/kg 14C-atrazine (14C-ATR) by gavage. 14C-ATR was administered to the nursing dam on postnatal day 3 by oral gavag...

  7. The HR96 activator, atrazine, reduces sensitivity of D. magna to triclosan and DHA.

    PubMed

    Sengupta, Namrata; Litoff, Elizabeth J; Baldwin, William S

    2015-06-01

    HR96 is a CAR/PXR/VDR ortholog in invertebrates, and a promiscuous endo- and xenobiotic nuclear receptor involved in acclimation to toxicants. Daphnia HR96 is activated by chemicals such as atrazine and linoleic acid (LA) (n-6 fatty acid), and inhibited by triclosan and docosahexaenoic acid (DHA) (n-3 fatty acid). We hypothesized that inhibitors of HR96 may block the protective responses of HR96 based on previously performed luciferase assays. Therefore, we performed acute toxicity tests with two-chemical mixtures containing a HR96 inhibitor (DHA or triclosan) and a HR96 activator (LA or atrazine). Surprisingly, results demonstrate that triclosan and DHA are less toxic when co-treated with 20-80 μM atrazine. Atrazine provides concentration-dependent protection as lower concentrations have no effect and higher concentrations cause toxicity. LA, a weaker HR96 activator, did not provide protection from triclosan or DHA. Atrazine's protective effects are presumably due to its ability to activate HR96 or other toxicologically relevant transcription factors and induce protective enzymes. Atrazine did not significantly induce glucosyltransferase, a crucial enzyme in triclosan detoxification. However, atrazine did increase antioxidant activities, crucial pathways in triclosan's toxicity, as measured through GST activity and the TROLOX equivalence assay. The increase in antioxidant capacity is consistent with atrazine providing protection from a wide range of toxicants that induce ROS, including triclosan and unsaturated fatty acids predisposed to lipid peroxidation.

  8. The effects of atrazine on spotted salamander embryos and their symbiotic alga.

    PubMed

    Olivier, Heather M; Moon, Brad R

    2010-04-01

    Worldwide amphibian declines have been a concern for biologists for the past several decades. The causes of such declines may include habitat loss, invasive species, pathogens, and man-made chemicals. Agricultural herbicides, in particular, are known to interfere with reproduction in amphibians and are likely contributing to population declines. We tested the effects of the herbicide atrazine on developing spotted salamanders (Ambystoma maculatum) and their symbiotic green alga Oophila amblystomatis. We exposed spotted salamander egg masses to atrazine at concentrations of 0 microg/L (control), 50, 100, 200, and 400 microg/L. Algae were eliminated in all atrazine treatments. Hatching success was significantly lower for atrazine-treated egg masses than for the controls, and was inversely related to atrazine concentration. The highest developmental stage reached by the embryos was significantly lower in the atrazine treatments than in the controls, and was inversely related to atrazine concentration. These results indicate that atrazine exposure affected spotted salamanders both directly by causing pathologies and mortality in embryos and indirectly by eliminating their symbiotic alga. PMID:19924530

  9. Predicting Atrazine Levels in Water Utility Intake Water for MCL Compliance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To protect human health, atrazine concentrations in drinking water must not exceed its maximum contaminant level (MCL) of 3 ug/L. The United States Environmental Protection Agency (USEPA) mandates that municipal water providers sample quarterly to determine MCL compliance. Atrazine levels were mon...

  10. Interactions of earthworms with Atrazine-degrading bacteria in an agricultural soil.

    PubMed

    Kersanté, Anne; Martin-Laurent, Fabrice; Soulas, Guy; Binet, Françoise

    2006-08-01

    In the last 10 years, accelerated mineralization of Atrazine (2-chloro-ethylamino-6-isopropylamino-s-triazine) has been evidenced in agricultural soils repeatedly treated with this herbicide. Here, we report on the interaction between earthworms, considered as soil engineers, and the Atrazine-degrading community. The impact of earthworm macrofauna on Atrazine mineralization was assessed in representative soil microsites of earthworm activities (gut contents, casts, burrow linings). Soil with or without earthworms, namely the anecic species Lumbricus terrestris and the endogenic species Aporrectodea caliginosa, was either inoculated or not inoculated with Pseudomonas sp. ADP, an Atrazine-degrading strain, and was either treated or not treated with Atrazine. The structure of the bacterial community, the Atrazine-degrading activity and the abundance of atzA, B and C sequences in soil microsites were investigated. Atrazine mineralization was found to be reduced in representative soil microsites of earthworm activities. Earthworms significantly affected the structure of soil bacterial communities. They also reduced the size of the inoculated population of Pseudomonas sp. ADP, thereby contributing to the diminution of the Atrazine-degrading genetic potential in representative soil microsites of earthworm activities. This study illustrates the regulation produced by the earthworms on functional bacterial communities involved in the fate of organic pollutants in soils. PMID:16867138

  11. Interactions of earthworms with Atrazine-degrading bacteria in an agricultural soil.

    PubMed

    Kersanté, Anne; Martin-Laurent, Fabrice; Soulas, Guy; Binet, Françoise

    2006-08-01

    In the last 10 years, accelerated mineralization of Atrazine (2-chloro-ethylamino-6-isopropylamino-s-triazine) has been evidenced in agricultural soils repeatedly treated with this herbicide. Here, we report on the interaction between earthworms, considered as soil engineers, and the Atrazine-degrading community. The impact of earthworm macrofauna on Atrazine mineralization was assessed in representative soil microsites of earthworm activities (gut contents, casts, burrow linings). Soil with or without earthworms, namely the anecic species Lumbricus terrestris and the endogenic species Aporrectodea caliginosa, was either inoculated or not inoculated with Pseudomonas sp. ADP, an Atrazine-degrading strain, and was either treated or not treated with Atrazine. The structure of the bacterial community, the Atrazine-degrading activity and the abundance of atzA, B and C sequences in soil microsites were investigated. Atrazine mineralization was found to be reduced in representative soil microsites of earthworm activities. Earthworms significantly affected the structure of soil bacterial communities. They also reduced the size of the inoculated population of Pseudomonas sp. ADP, thereby contributing to the diminution of the Atrazine-degrading genetic potential in representative soil microsites of earthworm activities. This study illustrates the regulation produced by the earthworms on functional bacterial communities involved in the fate of organic pollutants in soils.

  12. Occurrence of atrazine and degradates as contaminants of subsurface drainage and shallow groundwater

    SciTech Connect

    Jayachandran, K.; Steinheimer, T.R.; Moorman, T.B.

    1994-03-01

    Atrazine is a commonly used herbicide in corn (Zea mays L.) growing areas of the USA. Because of its heavy usage, moderate persistence, and mobility in soil, monitoring of atrazine movement under field conditions is essential to assess its potential to contaminate groundwater. Concentrations of atrazine, deisopropylatrazine (DIA), and deethlatraaine (DEA) were measured in subsurface drainage and shallow groundwater beneath continuous, no-till corn. Water samples were collected from the subsurface drain (tile) outlets and suction lysimeters in the growing seasons of 1990 and 1991, and analyzed for atrazine and two principle degradates won solid-phase extraction and HPLC. In 1990, atrazine concentration ranged from 1.3 to 5.1{mu}g L{sup -1} in tile-drain water and from 0.5 to 20.5 {mu}g L{sup -1} in lysimeter water. In general, concentrations of parent and degradates in solution were atrazine > DEA > DIA. Lesser levels of atrazine were measured in 1991 from Plots 2 and 4; however, greater concentrations of atrazine (6.0-8.4 {mu}g L{sup -1}) were measured from plot 5. Throughout the two growing seasons, atrazine concentration in Plot 5 tile-drain water was greater than that of Plots 2 and 4, suggesting a preferential movement of atrazine. Concentrations of DIA and DEA ranged from 0.1 to 2.2 and 0.9 to 3.2 {mu}g L{sup -1} respectively, indicating that the degradation products by themselves or in combination with parent atrazine can exceed the maximum contaminant level (mcl) of 3 {mu}g L{sup -1} even though atrazine by itself may be <3 {mu}g L{sup -1}. The deethylatrazine-to-atrazine ratio (DAR) is an indicator of residence time in soil during transport of atrazine to groundwater. In Plots 2 and 4, DAR values for tile-drain water ranged from 0.43 to 2.70 and 0.50 to 2.66 respectively. By comparison, a DAR of 0.38 to 0.60 was observed in Plot 5, suggesting less residence time in the soil. 38 refs., 5 figs., 4 tabs.

  13. Atrazine acts as an endocrine disrupter by inhibiting cAMP-specific phosphodiesterase-4

    SciTech Connect

    Kucka, Marek; Pogrmic-Majkic, Kristina; Fa, Svetlana; Stojilkovic, Stanko S.; Kovacevic, Radmila

    2012-11-15

    Atrazine, one of the most commonly used herbicides worldwide, acts as an endocrine disruptor, but the mechanism of its action has not been characterized. In this study, we show that atrazine rapidly increases cAMP levels in cultured rat pituitary and testicular Leydig cells in a concentration-dependent manner, but less effectively than 3-isobutyl-1-methylxanthine, a competitive non-specific inhibitor of phosphodiesterases (PDEs). In forskolin (an activator of adenylyl cyclase)- and probenecid (an inhibitor of cyclic nucleotide transporters)-treated cells, but not in 3-isobutyl-1-methylxanthine-treated cells, atrazine further increased cAMP levels, indicating that inhibition of PDEs accounts for accumulation of cAMP. In contrast to cAMP, atrazine did not alter cGMP levels, further indicating that it inhibits cAMP-specific PDEs. Atrazine-induced changes in cAMP levels were sufficient to stimulate prolactin release in pituitary cells and androgen production in Leydig cells, indicating that it acts as an endocrine disrupter both in cells that secrete by exocytosis of prestored hormones and in cells that secrete by de novo hormone synthesis. Rolipram abolished the stimulatory effect of atrazine on cAMP release in both cell types, suggesting that it acts as an inhibitor of PDE4s, isoforms whose mRNA transcripts dominate in pituitary and Leydig cells together with mRNA for PDE8A. In contrast, immortalized lacto-somatotrophs showed low expression of these mRNA transcripts and several fold higher cAMP levels compared to normal pituitary cells, and atrazine was unable to further increase cAMP levels. These results indicate that atrazine acts as a general endocrine disrupter by inhibiting cAMP-specific PDE4s. -- Highlights: ► Atrazine stimulates cAMP accumulation in pituitary and Leydig cells. ► Atrazine also stimulates PRL and androgens secretion. ► Stimulatory effects of atrazine were abolished in cells with IBMX-inhibited PDEs. ► Atrazine specificity toward c

  14. Butachlor impact on protein, free amino acid and glutamine contents, and on activity levels of aminotransferases, glutamate dehydrogenase and glutamine synthetase in the fresh water snail, Pila globosa (Swainson).

    PubMed

    Rajyalakshmi, T; Srinivas, T; Swamy, K V; Mohan, P M

    1996-08-01

    Biochemical changes followed in the freshwater snail Pila globosa (Swainson) during exposure to sublethal concentrations of the herbicide butachlor (26.6 ppm) in the ambient medium, at 3,6,12,24 and 48 h intervals, were marked by a significant decrease in total and soluble proteins, and an increase in free amino acids in foot and hepatopancreas up to 12 h before gradually recovering. Aminotransferase activities and glutamine content decreased during the early periods of exposure, while glutamate dehydrogenase activity increased. After an initial elevation, glutamate synthetase activity decreased at later intervals. Maximum effect of butachlor on the enzymes was seen after 12 h exposure. The extent of increase or decrease in different parameters examined varied between the two tissues studied. These changes are discussed in relation to the toxic stress of butachlor.

  15. Degradation and transformation of atrazine under catalyzed ozonation process with TiO2 as catalyst.

    PubMed

    Yang, Yixin; Cao, Hongbin; Peng, Pai; Bo, Hongmiao

    2014-08-30

    Degradation of atrazine by heterogeneously catalyzed ozonation was carried out with TiO2 in the form of rutile as the catalyst. Some experimental factors such as catalyst dose, ozone dose and initial concentration of atrazine were investigated for their influence on catalyzed ozonation process. Although atrazine was effectively removed from aqueous solution by catalyzed ozonation process, the mineralization degree only reached 56% at the experimental conditions. Five transformation products were identified by GC/MS analysis. The degradation of atrazine involved de-alkylation, de-chlorination and de-amination. Diaminotriazine and 5-azauracil were the de-chlorinated and de-aminated products, respectively. The evolution of concentration of transformation products during catalyzed ozonation process was compared with uncatalyzed ozonation to show the degradation pathway. Toxicity tests based on the inhibition of the luminescence emitted by Vibrio fisheri indicated the detoxification of atrazine by catalyzed ozonation. PMID:25106044

  16. Atrazine reduces reproduction in fathead minnow (Pimephales promelas): raw data report

    USGS Publications Warehouse

    Tillitt, Donald E.; Papoulias, Diana M.; Whyte, Jeffrey J.; Richter, Catherine A.

    2014-01-01

    The herbicide, atrazine, routinely is observed in surface and groundwaters, particularly in the “corn belt” region, a high-use area of the United States. Atrazine has demonstrated effects on reproduction in mammals and amphibians, but the characterization of endocrine-related effects in fish has received only limited attention. Peak concentrations of atrazine in surface water of streams from these agricultural areas coincide with annual spawning events of native fishes. Consequently, there was an unacceptable level of uncertainty in our understanding of the risks associated with the periods of greatest atrazine exposure and greatest vulnerability of certain species of fishes. For this reason, a study of the effects of atrazine on fathead minnow reproduction was undertaken (Tillitt and others, 2010). This report provides the raw data from that study.

  17. Detoxification of Atrazine by Endophytic Streptomyces sp. Isolated from Sugarcane and Detection of Nontoxic Metabolite.

    PubMed

    Mesquini, Josiane A; Sawaya, Alexandra C H F; López, Begonã G C; Oliveira, Valéria M; Miyasaka, Natalia R S

    2015-12-01

    Atrazine is still one of the most used agricultural pesticides worldwide and it has been recognized as a major contaminant of surface and ground water. The aims of this research were to isolate an endophytic microorganism from leaves of sugarcane, evaluate its ability to degrade atrazine, and investigate the formation of metabolites. By sequencing of the 16S rRNA gene, the endophytic isolate atz2 was identified as Streptomyces sp. The reduction in atrazine concentration by Streptomyces sp. atz2 was 98 % and UHPLC-MS/MS analyses showed the appearance of an unknown metabolite observed as m/z 311. Ecotoxicity tests with an aquatic organism, Daphnia similis, confirmed that this metabolite was nontoxic. This mechanism of detoxification of atrazine is different from the ones of other free-living microorganisms that inhabit the soil or rhizosphere. The results show new aspects of atrazine detoxification, highlighting a new role of endophytic bacteria in plants. PMID:26467569

  18. Detoxification of Atrazine by Endophytic Streptomyces sp. Isolated from Sugarcane and Detection of Nontoxic Metabolite.

    PubMed

    Mesquini, Josiane A; Sawaya, Alexandra C H F; López, Begonã G C; Oliveira, Valéria M; Miyasaka, Natalia R S

    2015-12-01

    Atrazine is still one of the most used agricultural pesticides worldwide and it has been recognized as a major contaminant of surface and ground water. The aims of this research were to isolate an endophytic microorganism from leaves of sugarcane, evaluate its ability to degrade atrazine, and investigate the formation of metabolites. By sequencing of the 16S rRNA gene, the endophytic isolate atz2 was identified as Streptomyces sp. The reduction in atrazine concentration by Streptomyces sp. atz2 was 98 % and UHPLC-MS/MS analyses showed the appearance of an unknown metabolite observed as m/z 311. Ecotoxicity tests with an aquatic organism, Daphnia similis, confirmed that this metabolite was nontoxic. This mechanism of detoxification of atrazine is different from the ones of other free-living microorganisms that inhabit the soil or rhizosphere. The results show new aspects of atrazine detoxification, highlighting a new role of endophytic bacteria in plants.

  19. Sensitivity of a green alga to atrazine is not enhanced by previous acute exposure.

    PubMed

    Baxter, Leilan; Brain, Richard; Prosser, Ryan; Solomon, Keith; Hanson, Mark

    2013-10-01

    Exposure to atrazine in small lotic systems can be episodic, with short-term pulses (peaks) followed by lower, decreasing concentrations. Algae and macrophytes recover rapidly from pulsed exposure to atrazine, but reported observations of population response to subsequent exposures are minimal and inconclusive. Consequently, the sensitivity of Pseudokirchneriella subcapitata to atrazine following a pulsed exposure was assessed. Exposure concentrations reflected amplifications of those observed in streams from highly vulnerable watersheds in regions of intense use. Initial pulsed atrazine exposure at 0, 150 or 300 μg/L for 24-h was followed by 72-h exposure to 0, 5, 10, 25, or 50 μg/L. Measured responses were cell density, growth rate, chlorophyll-a, and maximum quantum yield of photosystem II. Algal recovery was rapid and prior pulsed exposure to atrazine did not significantly affect subsequent sensitivity (EC10s, EC25s) for any endpoint, indicating no changes in tolerance at the population level for this species.

  20. Degradation and transformation of atrazine under catalyzed ozonation process with TiO2 as catalyst.

    PubMed

    Yang, Yixin; Cao, Hongbin; Peng, Pai; Bo, Hongmiao

    2014-08-30

    Degradation of atrazine by heterogeneously catalyzed ozonation was carried out with TiO2 in the form of rutile as the catalyst. Some experimental factors such as catalyst dose, ozone dose and initial concentration of atrazine were investigated for their influence on catalyzed ozonation process. Although atrazine was effectively removed from aqueous solution by catalyzed ozonation process, the mineralization degree only reached 56% at the experimental conditions. Five transformation products were identified by GC/MS analysis. The degradation of atrazine involved de-alkylation, de-chlorination and de-amination. Diaminotriazine and 5-azauracil were the de-chlorinated and de-aminated products, respectively. The evolution of concentration of transformation products during catalyzed ozonation process was compared with uncatalyzed ozonation to show the degradation pathway. Toxicity tests based on the inhibition of the luminescence emitted by Vibrio fisheri indicated the detoxification of atrazine by catalyzed ozonation.

  1. Potential impacts of seasonal variation on atrazine and metolachlor persistence in andisol soil.

    PubMed

    Jaikaew, Piyanuch; Boulange, Julien; Thuyet, Dang Quoc; Malhat, Farag; Ishihara, Satoru; Watanabe, Hirozumi

    2015-12-01

    To estimate the potential effect of seasonal variation on the fate of herbicides in andisol soil, atrazine and metolachlor residues were investigated through the summer and winter seasons during 2013 and 2014 under field condition. The computed half-lives of atrazine and metolachlor in soil changed significantly through the two seasons of the trial. The half-lives were shorter in summer season with 16.0 and 23.5 days for atrazine and metolachlor, respectively. In contrast, the half-lives were longer during the winter season with 32.7 and 51.8 days for atrazine and metolachlor, respectively. The analysis of soil water balance suggested that more pesticide was lost in deeper soil layers through infiltration in summer than in winter. In addition, during the summer season, metolachlor was more likely to leach into deeper soil layer than atrazine possibly due to high water solubility of metolachlor.

  2. Innate immune response of silver catfish (Rhamdia quelen) exposed to atrazine.

    PubMed

    Kreutz, Luiz Carlos; Barcellos, Leonardo José Gil; dos Santos, Ezequiel Davi; Pivato, Mateus; Zanatta, Rafael

    2012-10-01

    The impact of agrichemicals on aquatic vertebrate species has been a matter of increasing concern to researchers and environmentalist. In the present study, we evaluated the effects of a sublethal concentration of atrazine (10% of the LC(50-96 h)), a world-wide used herbicide, on the innate immune system of silver catfish (Rhamdia quelen). A significant reduction on phagocytic index, bacteria agglutination and bactericidal activity of the serum, serum lysozyme and total serum peroxidase activity was observed in fish exposed to atrazine for 24 h. After 10 days exposure to atrazine, only bactericidal activity of the serum, bacteria agglutination and total serum peroxidase activity were significantly reduced. Atrazine had no effect on the natural complement hemolytic activity. Our results demonstrate that atrazine decreases the innate immune response of fingerlings, which might increase its susceptibility to opportunistic pathogens.

  3. Atrazine and its metabolites as indicators of stream-aquifer interaction in Kansas, USA

    USGS Publications Warehouse

    Townsend, M.A.; Young, D.P.

    2000-01-01

    A survey of atrazine and its metabolites in Kansas ground water indicated that ground-water quality was impacted by stream-aquifer interaction between rivers in the Kansas River basin and their adjacent alluvial aquifers. Atrazine was detected in 19 of the 78 samples. The most common metabolite, deethylatrazine, was detected in 25 samples, 18 of which also had atrazine. The deethylatrazine/atrazine ratio (DAR) of < 1.0 indicates rapid movement of agricultural chemicals to ground water. In this study, 12 of 18 samples had DAR values < 1.0, suggesting rapid recharge to the aquifers. Hydroxyatrazine is seldom detected in ground water. In this study hydroxyatrazine was detected primarily in wells sited in alluvium of rivers. These rivers contain atrazine in varying concentrations. Results of the study suggest that stream-aquifer interaction is a process contributing to the presence of both atrazine and its metabolites in ground water in these areas.A survey of atrazine and its metabolites in Kansas ground water indicated that ground water quality was impacted by stream-aquifer interaction between rivers in the Kansas River basin and their adjacent alluvial aquifers. Atrazine was detected in 19 of the 78 samples. The most common metabolite, deethylatrazine, was detected in 25 samples, 18 of which also had atrazine. The deethylatrazine/attrazine ratio (DAR) of < 1.0 indicates rapid movement of agricultural chemicals to ground water. In this study, 12 of 18 samples had DAR values < 1.0, suggesting rapid recharge to the aquifers. Hydroxyatrazine is seldom detected in ground water. In this study hydroxyatrazine was detected primarily in wells sited in alluvium of rivers. These rivers contain atrazine in varying concentration. Results of the study suggest that stream-aquifer interaction is a process contributing to the presence of both attrazine and its metabolites in ground water in these areas.

  4. Reproduction, larval growth, and reproductive development in African clawed frogs (Xenopus laevis) exposed to atrazine.

    PubMed

    Du Preez, Louis H; Kunene, Nisile; Everson, Gideon J; Carr, James A; Giesy, John P; Gross, Timothy S; Hosmer, Alan J; Kendall, Ronald J; Smith, Ernest E; Solomon, Keith R; Van Der Kraak, Glen J

    2008-03-01

    Reproductive success and development of F2 offspring from F1 adult African clawed frogs (Xenopus laevis) exposed to atrazine throughout larval development and as sexually mature adults was examined. Larval X. laevis were exposed to one of four nominal concentrations of atrazine (0, 1, 10, 25 microg atrazine/l) beginning 96 hr after fertilization and continuing through two years post-metamorphosis. Clutch size and survival of offspring were used as measurement endpoints to gauge reproductive success of the F1 frogs. Larval survivorship and time to metamorphosis were used to gauge developmental success of the F2 offspring from atrazine-exposed frogs. Testes in F1 and F2 frogs were examined for incidence of anomalies, such as testicular ovarian follicles, and sex ratios in F2 offspring were investigated to determine if exposure to atrazine caused trans-generational effects (effects on F2 individuals due to exposure of F1 individuals). There were no effects of any of the studied concentrations of atrazine on clutch size of F1 frogs. There were also no effects on hatching success or time to metamorphosis. Sex ratios did not differ between F2 offspring among treatments. There was no evidence to suggest a transgenerational effect of atrazine on spawning success or reproductive development of X. laevis. This is consistent with the presence of robust populations of X. laevis in areas where they are exposed to atrazine that has been used for several decades for weed control in production of corn. Our observations also are consistent with the results of most other studies of frogs where no effects were found to be associated with exposure to atrazine. Our data do not support the hypothesis that atrazine significantly affects reproductive fitness and development of frogs.

  5. Acute Atrazine Exposure has Lasting Effects on Chemosensory Responses to Food Odors in Crayfish (Orconectes virilis).

    PubMed

    Belanger, Rachelle M; Mooney, Lauren N; Nguyen, Hung M; Abraham, Noor K; Peters, Tyler J; Kana, Maria A; May, Lauren A

    2016-02-01

    The herbicide atrazine is known to impact negatively olfactory-mediated behaviors in aquatic animals. We have shown that atrazine exposure has deleterious effects on olfactory-mediated behavioral responses to food odors in crayfish; however, recovery of chemosensory abilities post-atrazine exposure has not been investigated. We examined whether crayfish (Orconectes virilis) recovered chemosensory abilities after a 96-h exposure to sublethal, environmentally relevant concentrations of 80 ppb (µg/L) atrazine. Following treatment, we analyzed the ability of the crayfish to locate a food source using a Y-maze with one arm containing fish-flavored gelatin and the other containing unflavored gelatin. We compared the time spent in the food arm of the Y-maze, near the food source, as well as moving and walking speed of control and atrazine-treated crayfish. We also compared the number of crayfish that handled the food source and the amount of food consumed. Following 24-, 48-, and 72-h recovery periods in fresh water, behavioral trials were repeated to determine if there was any observable recovery of chemosensory-mediated behaviors. Atrazine-treated crayfish spent less time in the food arm, at the odor source, and were less successful at finding the food odor source than control crayfish for all times tested. Additionally, atrazine-treated crayfish consumed less fish-flavored than control crayfish; however, treatment did not affect locomotion. Overall, we found that crayfish are not able to recover chemosensory abilities 72 h post-atrazine exposure. Because crayfish rely heavily on their chemosensory abilities to acquire food, the negative impacts of atrazine exposure could affect population size in areas where atrazine is heavily applied.

  6. Determination of low-level agricultural residues in soft drinks and sports drinks by liquid chromatography/tandem mass spectrometry: single-laboratory validation.

    PubMed

    Paske, Nathan; Berry, Bryan; Schmitz, John; Sullivan, Darryl

    2007-01-01

    In this study, sponsored by PepsiCo Inc., a method was validated for measurement of 11 pesticide residues in soft drinks and sports drinks. The pesticide residues determined in this validation were alachlor, atrazine, butachlor, isoproturon, malaoxon, monocrotophos, paraoxon-methyl, phorate, phorate sulfone, phorate sulfoxide, and 2,4-dichlorophenoxyacetic acid (2,4-D) when spiked at 0.100 microg/L (1.00 microg/L for phorate). Samples were filtered (if particulate matter was present), degassed (if carbonated), and analyzed using liquid chromatography with tandem mass spectrometry. Quantitation was performed with matrix-matched external standard calibration solutions. The standard curve range for this assay was 0.0750 to 10.0 microg/L. The calibration curves for all agricultural residues had coefficient of determination (r2) values greater than or equal to 0.9900 with the exception of 2 values that were 0.9285 and 0.8514. Fortification spikes at 0.100 microg/L (1.00 microg/L for phorate) over the course of 2 days (n=8 each day) for 3 matrixes (7UP, Gatorade, and Diet Pepsi) yielded average percent recoveries (and percent relative standard deviations) as follows (n=48): 94.4 (15.2) for alachlor, 98.2 (13.5) for atrazine, 83.1 (41.6) for butachlor, 89.6 (24.5) for isoproturon, 87.9 (24.4) for malaoxon, 96.1 (9.26) for monocrotophos, 101 (25.7) for paraoxon-methyl, 86.6 (20.4) for phorate, 101 (16.5) for phorate sulfone, 93.6 (25.5) for phorate sulfoxide, and 98.2 (6.02) for 2,4-D. PMID:17474522

  7. Atrazine-induced hermaphroditism at 0.1 ppb in American leopard frogs (Rana pipiens): laboratory and field evidence.

    PubMed Central

    Hayes, Tyrone; Haston, Kelly; Tsui, Mable; Hoang, Anhthu; Haeffele, Cathryn; Vonk, Aaron

    2003-01-01

    Atrazine is the most commonly used herbicide in the United States and probably the world. Atrazine contamination is widespread and can be present in excess of 1.0 ppb even in precipitation and in areas where it is not used. In the current study, we showed that atrazine exposure (> or = to 0.1 ppb) resulted in retarded gonadal development (gonadal dysgenesis) and testicular oogenesis (hermaphroditism) in leopard frogs (Rana pipiens). Slower developing males even experienced oocyte growth (vitellogenesis). Furthermore, we observed gonadal dysgenesis and hermaphroditism in animals collected from atrazine-contaminated sites across the United States. These coordinated laboratory and field studies revealed the potential biological impact of atrazine contamination in the environment. Combined with reported similar effects in Xenopus laevis, the current data raise concern about the effects of atrazine on amphibians in general and the potential role of atrazine and other endocrine-disrupting pesticides in amphibian declines. PMID:12676617

  8. Competitive fluorescence assay for specific recognition of atrazine by magnetic molecularly imprinted polymer based on Fe3O4-chitosan.

    PubMed

    Liu, Guangyang; Li, Tengfei; Yang, Xin; She, Yongxin; Wang, Miao; Wang, Jing; Zhang, Min; Wang, Shanshan; Jin, Fen; Jin, Maojun; Shao, Hua; Jiang, Zejun; Yu, Hailong

    2016-02-10

    A novel fluorescence sensing strategy for determination of atrazine in tap water involving direct competition between atrazine and 5-(4,6-dichlorotriazinyl) aminofluorescein (5-DTAF), and which exploits magnetic molecularly imprinted polymer (MMIP), has been developed. The MMIP, based on Fe3O4-chitosan nanoparticles, was synthesized to recognize specific binding sites of atrazine. The recognition capability and selectivity of the MMIP for atrazine and other triazine herbicides was investigated. Under optimal conditions, the competitive reaction between 5-DTAF and atrazine was performed to permit quantitation. Fluorescence intensity changes at 515 nm was linearly related to the logarithm of the atrazine concentration for the range 2.32-185.4 μM. The detection limit for atrazine was 0.86μM (S/N=3) and recoveries were 77.6-115% in spiked tap water samples.

  9. Atrazine-induced hermaphroditism at 0.1 ppb in American leopard frogs (Rana pipiens): laboratory and field evidence.

    PubMed

    Hayes, Tyrone; Haston, Kelly; Tsui, Mable; Hoang, Anhthu; Haeffele, Cathryn; Vonk, Aaron

    2003-04-01

    Atrazine is the most commonly used herbicide in the United States and probably the world. Atrazine contamination is widespread and can be present in excess of 1.0 ppb even in precipitation and in areas where it is not used. In the current study, we showed that atrazine exposure (> or = to 0.1 ppb) resulted in retarded gonadal development (gonadal dysgenesis) and testicular oogenesis (hermaphroditism) in leopard frogs (Rana pipiens). Slower developing males even experienced oocyte growth (vitellogenesis). Furthermore, we observed gonadal dysgenesis and hermaphroditism in animals collected from atrazine-contaminated sites across the United States. These coordinated laboratory and field studies revealed the potential biological impact of atrazine contamination in the environment. Combined with reported similar effects in Xenopus laevis, the current data raise concern about the effects of atrazine on amphibians in general and the potential role of atrazine and other endocrine-disrupting pesticides in amphibian declines.

  10. Transcriptome analysis of Glomus mosseae/Medicago sativa mycorrhiza on atrazine stress.

    PubMed

    Song, Fuqiang; Li, Jize; Fan, Xiaoxu; Zhang, Quan; Chang, Wei; Yang, Fengshan; Geng, Gui

    2016-01-01

    Arbuscular mycorrhizal fungi (AMF) protect host plants against diverse biotic and abiotic stresses, and promote biodegradation of various contaminants. In this study effect of Glomus mosseae/Medicago sativa mycorrhiza on atrazine degradation was investigated. It was observed that the atrazine degradation rates with any addition level in mycorrhizal treatments were all significantly higher than those in non-mycorrhizal treatments. When atrazine was applied at 20 mg kg(-1), the removal efficiency was up to 74.65%. Therefore, G. mosseae can be considered as ideal inhabitants of technical installations to facilitate phytoremediation. Furthermore, a total of 10.4 Gb was used for de novo transcriptome assembly, resulting in a comprehensive data set for the identification of genes corresponding to atrazine stress in the AM association. After comparative analysis with edgeR, a total of 2,060 differential expressed genes were identified, including 570 up-regulated genes and 1490 down-regulated genes. After excluding 'function unknown' and 'general function predictions only' genes, 172 up-regulated genes were obtained. The differentially expressed genes in AM association with and without atrazine stress were associated with molecular processes/other proteins, zinc finger protein, intracellular/extracellular enzymes, structural proteins, anti-stress/anti-disease protein, electron transport-related protein, and plant growth associated protein. Our results not only prove AMF has important ecological significance on atrazine degradation but also provide evidence for the molecular mechanisms of atrazine degradation by AMF. PMID:26833403

  11. Transcriptome analysis of Glomus mosseae/Medicago sativa mycorrhiza on atrazine stress.

    PubMed

    Song, Fuqiang; Li, Jize; Fan, Xiaoxu; Zhang, Quan; Chang, Wei; Yang, Fengshan; Geng, Gui

    2016-02-02

    Arbuscular mycorrhizal fungi (AMF) protect host plants against diverse biotic and abiotic stresses, and promote biodegradation of various contaminants. In this study effect of Glomus mosseae/Medicago sativa mycorrhiza on atrazine degradation was investigated. It was observed that the atrazine degradation rates with any addition level in mycorrhizal treatments were all significantly higher than those in non-mycorrhizal treatments. When atrazine was applied at 20 mg kg(-1), the removal efficiency was up to 74.65%. Therefore, G. mosseae can be considered as ideal inhabitants of technical installations to facilitate phytoremediation. Furthermore, a total of 10.4 Gb was used for de novo transcriptome assembly, resulting in a comprehensive data set for the identification of genes corresponding to atrazine stress in the AM association. After comparative analysis with edgeR, a total of 2,060 differential expressed genes were identified, including 570 up-regulated genes and 1490 down-regulated genes. After excluding 'function unknown' and 'general function predictions only' genes, 172 up-regulated genes were obtained. The differentially expressed genes in AM association with and without atrazine stress were associated with molecular processes/other proteins, zinc finger protein, intracellular/extracellular enzymes, structural proteins, anti-stress/anti-disease protein, electron transport-related protein, and plant growth associated protein. Our results not only prove AMF has important ecological significance on atrazine degradation but also provide evidence for the molecular mechanisms of atrazine degradation by AMF.

  12. Transcriptome analysis of Glomus mosseae/Medicago sativa mycorrhiza on atrazine stress

    PubMed Central

    Song, Fuqiang; Li, Jize; Fan, Xiaoxu; Zhang, Quan; Chang, Wei; Yang, Fengshan; Geng, Gui

    2016-01-01

    Arbuscular mycorrhizal fungi (AMF) protect host plants against diverse biotic and abiotic stresses, and promote biodegradation of various contaminants. In this study effect of Glomus mosseae/Medicago sativa mycorrhiza on atrazine degradation was investigated. It was observed that the atrazine degradation rates with any addition level in mycorrhizal treatments were all significantly higher than those in non- mycorrhizal treatments. When atrazine was applied at 20 mg kg−1, the removal efficiency was up to 74.65%. Therefore, G. mosseae can be considered as ideal inhabitants of technical installations to facilitate phytoremediation. Furthermore, a total of 10.4 Gb was used for de novo transcriptome assembly, resulting in a comprehensive data set for the identification of genes corresponding to atrazine stress in the AM association. After comparative analysis with edgeR, a total of 2,060 differential expressed genes were identified, including 570 up-regulated genes and 1490 down-regulated genes. After excluding ‘function unknown’ and ‘general function predictions only’ genes, 172 up-regulated genes were obtained. The differentially expressed genes in AM association with and without atrazine stress were associated with molecular processes/other proteins, zinc finger protein, intracellular/extracellular enzymes, structural proteins, anti-stress/anti-disease protein, electron transport-related protein, and plant growth associated protein. Our results not only prove AMF has important ecological significance on atrazine degradation but also provide evidence for the molecular mechanisms of atrazine degradation by AMF. PMID:26833403

  13. Identification of an atrazine-degrading benzoxazinoid in Eastern gamagrass (Tripsacum dactyloides).

    PubMed

    Willett, Cammy D; Lerch, Robert N; Lin, Chung-Ho; Goyne, Keith W; Leigh, Nathan D; Roberts, Craig A

    2013-08-28

    This study was part of a broader effort to identify and characterize promising atrazine-degrading phytochemicals in Eastern gamagrass (Tripsacum dactyloides ; EG) roots for the purpose of mitigating atrazine transport from agroecosystems. The objective of this study was to isolate and identify atrazine-degrading compounds in EG root extracts. Eastern gamagrass roots were extracted with methanol, and extracts were subjected to a variety of separation techniques. Fractions from each level of separation were tested for atrazine-degrading activity by a simple assay. Compounds were identified using high-performance liquid chromatography-tandem mass spectrometry. Results from the experiments identified 2-β-d-glucopyranosyloxy-4-hydroxy-1,4-benzoxazin-3-one (DIBOA-Glc) as the compound responsible for atrazine degradation in the root extract fractions collected. 2-β-d-Glucopyranosyloxy-1,4-benzoxazin-3-one (HBOA-Glc) was also identified in the root extract fractions, but it did not demonstrate activity against atrazine. Estimated root tissue concentrations were 210 mg kg(-1) (wet wt basis) for DIBOA-Glc and 71 mg kg(-1) for HBOA-Glc (dry wt basis, 710 ± 96 and 240 ± 74 mg kg(-1), respectively). This research was the first to describe the occurrence and concentrations of an atrazine-degrading benzoxazinone compound isolated from EG tissue. PMID:23885866

  14. Gonadal development of larval male Xenopus laevis exposed to atrazine in outdoor microcosms

    USGS Publications Warehouse

    Jooste, A.M.; Du Preez, L.H.; Carr, J.A.; Giesy, J.P.; Gross, T.S.; Kendall, R.J.; Smith, E.E.; Van Der Kraak, G. L.; Solomon, K.R.

    2005-01-01

    The potential effects of atrazine on gonadal development in metamorphs and subadults of the African clawed frog (Xenopus laevis) were studied under conditions of natural photoperiod and temperatures in outdoor microcosms from August 2002 to June 2003 in South Africa. Triplicate 1100 L microcosms for each nominal concentration of 0.0, 1, 10, and 25 ??g of atrazine/L were used. Measured atrazine concentrations varied <25% throughout the study, and no atrazine was detected in the control microcosms. Tadpoles developed well at all concentrations. On the basis of histological examination of testes of recently metamorphosed stage 66 frogs, 57% of the individuals in the reference group exhibited testicular oocytes as compared with 57, 59, and 39% of the 1, 10, and 25 ??g/L atrazine groups, respectively. The average prevalence of testicular oocytes for all of the treatments including the controls was 54% in a single testis, while, in 35% of individuals, testicular oocytes were observed in both testes. The number of testicular oocytes per individual ranged from 0 to 58 with means of 9.5, 9.8, 8.5, and 11.1 for the 0.0, 1, 10, and 25 ??g of atrazine/L groups, respectively. Ten months after metamorphosis, another subset of juveniles was examined, and the maximum number of testicular oocytes observed was five in one animal. The presence of testicular oocytes was not related to exposure to atrazine and may be a natural phenomenon during ontogeny. ?? 2005 American Chemical Society.

  15. Atrazine biodegradation to deisopropylatrazine and deethylatrazine in coastal sediments of different land uses.

    PubMed

    Aelion, C M; Mathur, P P

    2001-11-01

    Atrazine, a triazine herbicide widely used in the United States, contributes to surface-water and groundwater contamination, as can deisopropylatrazine (DIA) and deethylatrazine (DEA), two of its microbial degradation products. Production of DIA and DEA by native bacteria in aquatic sediments has not been investigated thoroughly. We assessed atrazine and production of DIA and DEA over time in coastal aquatic sediments associated with different land uses including creeks from an undeveloped preserve and a suburban development, a golf course drainage ditch, and a contaminated commercial harbor. Sediments were incubated in microcosms, spiked with U-14C-atrazine, extracted, and analyzed for 14C in a liquid scintillation counter. Atrazine, DIA, and DEA also were quantified by gas chromatography-mass spectrometry. The amount of 14C recovered varied at each site as a function of the sediment organic carbon content and decreased significantly over time. Both DEA and DIA were measured primarily in the aqueous phase. Transformation was more extensive to DIA than to DEA. The ratio of DIA to atrazine recovered from the undeveloped preserve was as high as 0.13. In contrast, the golf course had limited biotransformation, and had the greatest atrazine recoveries so atrazine, not DEA and DIA, may have a greater impact at this site.

  16. The HR96 activator, atrazine, reduces sensitivity of D. magna to triclosan and DHA

    PubMed Central

    Sengupta, Namrata; Litoff, Elizabeth J.; Baldwin, William S.

    2015-01-01

    HR96 is a CAR/PXR/VDR ortholog in invertebrates, and a promiscuous endo- and xenobiotic nuclear receptor involved in acclimation to toxicants. Daphnia HR96 is activated by chemicals such as atrazine and linoleic acid (LA) (n-6 fatty acid), and inhibited by triclosan and docosahexaenoic acid (DHA)(n-3 fatty acid). We hypothesized that inhibitors of HR96 may block the protective responses of HR96 based on previously performed luciferase assays. Therefore, we performed acute toxicity tests with two-chemical mixtures containing a HR96 inhibitor (DHA or triclosan) and a HR96 activator (LA or atrazine). Surprisingly, results demonstrate that triclosan and DHA are less toxic when co-treated with 20–80 μM atrazine. Atrazine provides concentration-dependent protection as lower concentrations have no effect and higher concentrations cause toxicity. LA, a weaker HR96 activator, did not provide protection from triclosan or DHA. Atrazine’s protective effects are presumably due to its ability to activate HR96 or other toxicologically relevant transcription factors and induce protective enzymes. Atrazine did not significantly induce glucosyltransferase, a crucial enzyme in triclosan detoxification. However, atrazine did increase antioxidant activities, crucial pathways in triclosan’s toxicity, as measured through GST activity and the TROLOX equivalence assay. The increase in antioxidant capacity is consistent with atrazine providing protection from a wide range of toxicants that induce ROS, including triclosan and unsaturated fatty acids predisposed to lipid peroxidation. PMID:25747156

  17. Atrazine Affects Phosphoprotein and Protein Expression in MCF-10A Human Breast Epithelial Cells

    PubMed Central

    Huang, Peixin; Yang, John; Song, Qisheng; Sheehan, David

    2014-01-01

    Atrazine, a member of the 2-chloro-s-triazine family of herbicides, is the most widely used pesticide in the world and often detected in agriculture watersheds. Although it was generally considered as an endocrine disruptor, posing a potential threat to human health, the molecular mechanisms of atrazine effects remain unclear. Using two-dimensional gel electrophoresis, we identified a panel of differentially expressed phosphoproteins and total proteins in human breast epithelial MCF-10A cells after being exposed to environmentally relevant concentrations of atrazine. Atrazine treatments for 6 h resulted in differential expression of 4 phosphoproteins and 8 total-proteins as compared to the control cells (>1.5-fold, p < 0.05). MALDI-TOF MS/MS analysis revealed that the differentially expressed proteins belong to various cellular compartments (nucleus, cytosol, membrane) and varied in function, including those regulating the stress response such as peroxiredoxin I, HSP70 and HSP27; structural proteins such as tropomyosin and profilin 1; and oncogenesis proteins such as ANP32A. Six of the 12 identified proteins were verified by quantitative PCR for their transcript levels. The most up-regulated phosphoprotein by atrazine treatment, ANP32A, was further analyzed for its expression, distribution and cellular localization using Western blot and immunocytochemical approaches. The results revealed that ANP32 expression after atrazine treatment increased dose and time dependently and was primarily located in the nucleus. This study may provide new evidence on the potential toxicity of atrazine in human cells. PMID:25275270

  18. Preparation and characterization of a lipoid adsorption material and its atrazine removal performance.

    PubMed

    Chen, Zhiqiang; Wen, Qinxue; Lian, Jiaxiang; Ren, Nanqi

    2011-01-01

    A novel adsorbent named lipoid adsorption material (LAM), with a hydrophobic nucleolus (triolein) and a hydrophilic membrane structure (polyamide), was synthesized to remove hydrophobic organic chemicals (HOCs) from solution. Triolein, a type of lipoid, was entrapped by the polyamide membrane through an interfacial polymerization reaction. The method of preparation and the structure of the LAM were investigated and subsequent experiments were conducted to determine the characteristics of atrazine (a type of HOC) removal from wastewater using LAM as the adsorbent. The results showed that LAM had a regular structure compared with the prepolymer, where compact particles were linked with each other and openings were present in the structure of the LAM in which the fat drops formed from triolein were entrapped. In contrast to the atrazine adsorption behavior of powdered activated carbon (PAC), LAM showed a persistent adsorption capacity for atrazine when initial concentrations of 0.57, 1.12, 8.31 and 19.01 mg/L were present, and the equilibrium time was 12 hr. Using an 8 mg/L initial concentration of atrazine as an indicator of HOCs in aqueous solution, experiments on the adsorption capacity of the LAM showed 69.3% removal within 6-12 hr contact time, which was close to the 75.5% removal of atrazine by PAC. Results indicated that LAM has two atrazine removal mechanisms, namely the bioaccumulation of atrazine by the nucleous material and physical adsorption to the LAM membrane. Bioaccumulation was the main removal mechanism. PMID:22128536

  19. Wire-cylinder dielectric barrier discharge induced degradation of aqueous atrazine.

    PubMed

    Zhu, Dan; Jiang, Lin; Liu, Run-Long; Chen, Pei; Lang, Lin; Feng, Jing-Wei; Yuan, Shou-Jun; Zhao, Da-Yong

    2014-12-01

    The wire-cylinder dielectric barrier discharge reactor was adopted for removal of aqueous atrazine. The effect of different parameters on the degradation efficiency of atrazine was investigated, and the degradation mechanism of atrazine was studied. The experimental results showed that when the discharge power was 50 W and the air flow rate was 140 L h(-1), 93.7% of atrazine was degraded after 18 min of discharge time. The concentrations of generated O3 and H2O2 increased with increasing discharge time. The pH decreased from 6.80 to 2.50, 12.7% of TOC was removed after 18 min. The concentrations of generated Cl(-) and NO3(-) increased significantly during the degradation process of atrazine, and the decreasing toxicity trend was observed for the treated atrazine solution. The degradation byproducts of atrazine were identified using liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS), which might be formed mainly in dechlorination hydroxylation, alkyl oxidation, dechlorination hydroxylation combined with alkyl oxidation and demethylation oxidation reactions. PMID:25268075

  20. Atrazine affects phosphoprotein and protein expression in MCF-10A human breast epithelial cells.

    PubMed

    Huang, Peixin; Yang, John; Song, Qisheng

    2014-10-01

    Atrazine, a member of the 2-chloro-s-triazine family of herbicides, is the most widely used pesticide in the world and often detected in agriculture watersheds. Although it was generally considered as an endocrine disruptor, posing a potential threat to human health, the molecular mechanisms of atrazine effects remain unclear. Using two-dimensional gel electrophoresis, we identified a panel of differentially expressed phosphoproteins and total proteins in human breast epithelial MCF-10A cells after being exposed to environmentally relevant concentrations of atrazine. Atrazine treatments for 6 h resulted in differential expression of 4 phosphoproteins and 8 total-proteins as compared to the control cells (>1.5-fold, p<0.05). MALDI-TOF MS/MS analysis revealed that the differentially expressed proteins belong to various cellular compartments (nucleus, cytosol, membrane) and varied in function, including those regulating the stress response such as peroxiredoxin I, HSP70 and HSP27; structural proteins such as tropomyosin and profilin 1; and oncogenesis proteins such as ANP32A. Six of the 12 identified proteins were verified by quantitative PCR for their transcript levels. The most up-regulated phosphoprotein by atrazine treatment, ANP32A, was further analyzed for its expression, distribution and cellular localization using Western blot and immunocytochemical approaches. The results revealed that ANP32 expression after atrazine treatment increased dose and time dependently and was primarily located in the nucleus. This study may provide new evidence on the potential toxicity of atrazine in human cells.

  1. Differential morphological effects in rat corpora lutea among ethylene glycol monomethyl ether, atrazine, and bromocriptine.

    PubMed

    Taketa, Yoshikazu; Inoue, Kaoru; Takahashi, Miwa; Yamate, Jyoji; Yoshida, Midori

    2013-07-01

    Ethylene glycol monomethyl ether (EGME) or atrazine induces luteal cell hypertrophy in rats. Our previous study suggested that EGME stimulates both new and old corpora lutea (CL), while atrazine stimulates new CL. Bromocriptine (BRC) is known to suppress the luteolysis in rats. This study investigated the light- and electron-microscopic luteal changes induced by EGME, atrazine, or BRC. Female rats were treated with EGME (300 mg/kg/day), BRC (2 mg/kg/day), EGME and BRC (EGME + BRC), or atrazine (300 mg/kg/day) for 7 days. Luteal cell hypertrophy induced by EGME, EGME + BRC, and atrazine was subclassified into the following two types: CL hypertrophy, vacuolated type (CL-V) characterized by intracytoplasmic fine vacuoles, and CL hypertrophy, eosinophilic type (CL-E) characterized by eosinophilic and abundant cytoplasm. The proportions of CL-V and CL-E were different among the treatments. BRC-treated old CL showed lower proportion of endothelial cells and fibroblasts than normal old CL. Ultrastructural observation revealed that the luteal cells of CL-V contained abundant lipid droplets, whereas those of CL-E in EGME and EGME + BRC groups showed uniformly well-developed smooth endoplasmic reticulum. No clear ultrastructural difference was observed between the control CL and atrazine-treated CL-E. These results indicate that EGME, atrazine, and BRC have differential luteal morphological effects.

  2. An altered Q sub B polypeptide as the basis for atrazine resistance in photoautotrophic potato cells

    SciTech Connect

    Smeda, R.J.; Hasegawa, P.M.; Weller, S.C. )

    1990-05-01

    A photoautotrophic potato cell line (variant) was isolated and is capable of sustained growth in media containing the herbicide atrazine at concentrations up to 100-fold greater than the lethal concentration (1.0 {mu}M) for the unselected (wild type) cell line. The basis for atrazine resistance could not be identified by differential uptake or metabolism. Photosynthetic electron transport rates for both intact cell and isolated thylakoid membranes from chloroplasts were unaffected in variant cells at atrazine concentrations up to 100-fold greater than for wild type cells. Photoaffinity labeling of isolated thylakoid membranes from both cell lines with {sup 14}C-azidoatrazine revealed an altered Q{sub B} polypeptide in variant cells resulting in low or no affinity for atrazine. A portion of the chloroplast psbA gene, encoding the Q{sub B} polypeptide, was sequenced for both cell lines. The basis for atrazine resistance in variant cells was identified as a single base change resulting in the alteration of serine to threonine at position 264 of the Q{sub B} polypeptide. In addition to atrazine resistance, variant cells exhibit enhanced tolerance to the herbicides DCMU and metribuzin, but greater sensitivity to bentazon. No reductions in variant cell growth and photosynthetic efficiency in the absence of atrazine were observed.

  3. Wire-cylinder dielectric barrier discharge induced degradation of aqueous atrazine.

    PubMed

    Zhu, Dan; Jiang, Lin; Liu, Run-Long; Chen, Pei; Lang, Lin; Feng, Jing-Wei; Yuan, Shou-Jun; Zhao, Da-Yong

    2014-12-01

    The wire-cylinder dielectric barrier discharge reactor was adopted for removal of aqueous atrazine. The effect of different parameters on the degradation efficiency of atrazine was investigated, and the degradation mechanism of atrazine was studied. The experimental results showed that when the discharge power was 50 W and the air flow rate was 140 L h(-1), 93.7% of atrazine was degraded after 18 min of discharge time. The concentrations of generated O3 and H2O2 increased with increasing discharge time. The pH decreased from 6.80 to 2.50, 12.7% of TOC was removed after 18 min. The concentrations of generated Cl(-) and NO3(-) increased significantly during the degradation process of atrazine, and the decreasing toxicity trend was observed for the treated atrazine solution. The degradation byproducts of atrazine were identified using liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS), which might be formed mainly in dechlorination hydroxylation, alkyl oxidation, dechlorination hydroxylation combined with alkyl oxidation and demethylation oxidation reactions.

  4. Proteomics analysis of Xenopus laevis gonad tissue following chronic exposure to atrazine.

    PubMed

    Chen, Xiuping; Wang, Jiamei; Zhu, Haojun; Ding, Jiatong; Peng, Yufa

    2015-08-01

    Atrazine is the most commonly detected pesticide contaminant in ground and surface water. Previous studies have shown that atrazine is an endocrine disruptor owing to its adverse effects on the male reproductive system in several vertebrates, but very few molecular mechanisms for these effects have been revealed. In the present study, Xenopus laevis were exposed to 100 ppb of atrazine for 120 d, and then the isobaric tags for relative and absolute quantitation (iTRAQ) technique was used to detect global changes in protein profiles of the testes and ovaries. The results showed that 100 ppb of atrazine exposure adversely affected the growth of X. laevis and did not induce hermaphroditism but delayed or prevented the development of male seminiferous tubules. Proteomic analysis showed that atrazine altered expression of 143 and 121 proteins in the testes and ovaries, respectively, and most of them are involved in cellular and metabolic processes and biological regulation based on their biological processes. In addition, apoptosis, tight junctions, and metabolic pathways were significantly altered in the atrazine-treated gonads. Based on the above results, it is postulated that the reproductive toxicity of atrazine may be the result of disruption of tight junctions and metabolic signaling pathways and/or induction of apoptosis in germ cells.

  5. Adsorption and desorption of atrazine and deethylatrazine by low organic carbon geologic materials

    SciTech Connect

    Roy, W.R.; Krapac, I.G.

    1994-05-01

    The adsorption and desorption of atrazine (2-chloro-4-ethylamino-6- isopropylamino-s-triazine) and a primary metabolite, deethylatrazine (2-amino-4-chloro-6-isopropylamino-s-triazine; DEA), by low organic C ({le} 3.3 g kg{sup -1}) materials were measured by batch-equilibrium techniques. The adsorbents were samples of glacial outwash sand, till, and stream sediments. The adsorption of both atrazine and DEA conformed to linear isotherms. The adsorption of atrazine by most of the absorbents yielded apparent K, values that were in excess of those based on surface agricultural soils. Adsorption correlated with only the pH of the sand-water suspensions. The desorption of atrazine was hysteretic under the conditions of the measurement. DEA had a lower affinity for the same adsorbents; the mean ratio of Kd values of DEA to those of atrazine was 0.37 {+-} 0.20. DEA adsorption did not correlate with organic C, surface area, clay content of the adsorbents, or with the pH of the suspensions. DEA adsorption, unlike atrazine, tended to be reversible. There was a linear relationship between the adsorption constants of atrazine and those of DEA. 40 refs., 8 figs., 3 tabs.

  6. Twenty years of long-term Atrazine monitoring in a shallow aquifer in Western Germany (Invited)

    NASA Astrophysics Data System (ADS)

    Vereecken, H.; Vonberg, D.; Putz, T.; Vanderborght, J.

    2013-12-01

    Atrazine, one of the most frequent applied pesticides worldwide, was banned in Germany in 1991 due to exceeded threshold values in ground- and drinking waters. Monitoring of atrazine was hence introduced in the Zwischenscholle aquifer, exposed to intensive agricultural land use and susceptible to contaminants due to a shallow water table. In total 60 observation wells were monitored since 1991, of which 11 are sampled monthly today. Descriptive statistics of monitoring data were derived using the 'regression on order statistics' (ROS) data censoring approach, estimating values for nondetects. The monitoring data shows that even 20 years after the ban of atrazine, the concentrations in groundwater are on a constant level without any considerable decrease. The spatial distribution of atrazine concentrations is highly heterogeneous with observation wells exhibiting constantly concentrations above the threshold on the one hand and observation wells where concentrations are frequently below the limit of quantification (LOQ) on the other hand. A deethylatrazine-to-atrazine ratio (DAR) was used to distinguish between diffuse - and point-source contamination, with a global mean value of 0.84 indicating mainly diffuse contamination. Principle Component Analysis (PCA) was applied to the monitoring dataset and relationships of triazine compounds became obvious. Accordingly the metabolite desisopropylatrazine was exclusively associated with the occurrence of the parent compound simazine and not atrazine, whereas deethylatrazine was clearly related to atrazine.

  7. Contaminant effects on host-parasite interactions: atrazine, frogs, and trematodes.

    PubMed

    Koprivnikar, Janet; Forbes, Mark R; Baker, Robert L

    2007-10-01

    The effects of contaminants on multispecies interactions can be difficult to predict. The herbicide atrazine is commonly used in North America for corn crops, runs off into wetlands, and has been implicated in the increasing susceptibility of larval frogs to trematode parasites. Using experimental challenges with free-living stages of trematodes (cercariae), it was found that Rana sylvatica tadpoles exposed to 30 microg/L of atrazine had significantly higher intensity of parasitism than did larval frogs either not exposed or exposed to 3 microg/L of atrazine. This result could not be explained by high concentrations of atrazine diminishing antiparasite behavior of tadpoles. Furthermore, when tadpoles and cercariae both were exposed to the same concentration of atrazine, either 3 or 30 microg/L, the abundance of formed cysts was not different from the condition in which both were housed at 0 microg/L of atrazine. Atrazine appears to be debilitating to both free-living cercariae and tadpoles. Studies examining relations between parasitism and contaminant levels must account for such combined effects as well as influences on other interacting species (e.g., first intermediate snail hosts).

  8. Hermaphroditic, demasculinized frogs after exposure to the herbicide atrazine at low ecologically relevant doses.

    PubMed

    Hayes, Tyrone B; Collins, Atif; Lee, Melissa; Mendoza, Magdelena; Noriega, Nigel; Stuart, A Ali; Vonk, Aaron

    2002-04-16

    Atrazine is the most commonly used herbicide in the U.S. and probably the world. It can be present at several parts per million in agricultural runoff and can reach 40 parts per billion (ppb) in precipitation. We examined the effects of atrazine on sexual development in African clawed frogs (Xenopus laevis). Larvae were exposed to atrazine (0.01-200 ppb) by immersion throughout larval development, and we examined gonadal histology and laryngeal size at metamorphosis. Atrazine (> or =0.1 ppb) induced hermaphroditism and demasculinized the larynges of exposed males (> or =1.0 ppb). In addition, we examined plasma testosterone levels in sexually mature males. Male X. laevis suffered a 10-fold decrease in testosterone levels when exposed to 25 ppb atrazine. We hypothesize that atrazine induces aromatase and promotes the conversion of testosterone to estrogen. This disruption in steroidogenesis likely explains the demasculinization of the male larynx and the production of hermaphrodites. The effective levels reported in the current study are realistic exposures that suggest that other amphibian species exposed to atrazine in the wild could be at risk of impaired sexual development. This widespread compound and other environmental endocrine disruptors may be a factor in global amphibian declines.

  9. Gonadal development of larval male Xenopus laevis exposed to atrazine in outdoor microcosms.

    PubMed

    Jooste, Alarik M; Du Preez, Louis H; Carr, James A; Giesy, John P; Gross, Timothy S; Kendall, Ronald J; Smith, Ernest E; Van der Kraak, Glen L; Solomon, Keith R

    2005-07-15

    The potential effects of atrazine on gonadal development in metamorphs and subadults of the African clawed frog (Xenopus laevis) were studied under conditions of natural photoperiod and temperatures in outdoor microcosms from August 2002 to June 2003 in South Africa. Triplicate 1100 L microcosms for each nominal concentration of 0.0, 1, 10, and 25 microg of atrazine/L were used. Measured atrazine concentrations varied <25% throughout the study, and no atrazine was detected in the control microcosms. Tadpoles developed well at all concentrations. On the basis of histological examination of testes of recently metamorphosed stage 66 frogs, 57% of the individuals in the reference group exhibited testicular oocytes as compared with 57, 59, and 39% of the 1, 10, and 25 microg/L atrazine groups, respectively. The average prevalence of testicular oocytes for all of the treatments including the controls was 54% in a single testis, while, in 35% of individuals, testicular oocytes were observed in both testes. The number of testicular oocytes per individual ranged from 0 to 58 with means of 9.5, 9.8, 8.5, and 11.1 forthe 0.0, 1, 10, and 25 microg of atrazine/L groups, respectively. Ten months after metamorphosis, another subset of juveniles was examined, and the maximum number of testicular oocytes observed was five in one animal. The presence of testicular oocytes was not related to exposure to atrazine and may be a natural phenomenon during ontogeny.

  10. Effects of atrazine and cyanazine on chlorpyrifos toxicity in Chironomus tentans (Diptera: Chironomidae).

    PubMed

    Jin-Clark, Ying; Lydy, Michael J; Zhu, Kun Yan

    2002-03-01

    Toxicities of two triazine herbicides (atrazine and cyanazine) and an organophosphate insecticide (chlorpyrifos) were evaluated individually and with each herbicide in binary combination with chlorpyrifos using fourth-instar larvae of the aquatic midge, Chironomus tentans. Chlorpyrifos at 0.25 microg/L resulted in an effect in less than 10% of midges in 48-h acute toxicity bioassays. Neither atrazine nor cyanazine alone at relatively high concentrations (up to 1,000 microg/L) caused significant acute toxicity to C. tentans. However, atrazine and cyanazine caused significant synergistic effects on the toxicity of chlorpyrifos when midges were exposed to mixtures of atrazine or cyanazine (10, 100, 1,000 microg/L) with chlorpyrifos (0.25 microg/L). At fixed concentrations (200 microg/L) of the herbicides, toxicity of chlorpyrifos was enhanced by 1.8- and 2.2-fold by atrazine and cyanazine, respectively, at the 50% effective concentration levels. Although atrazine and cyanazine are not effective inhibitors of acetylcholinesterase (AChE) in vitro, the synergism of the two triazine herbicides with chlorpyrifos was associated with increased in vivo inhibition of AChE in midges. We observed a positive correlation between the degree of inhibition of AChE and the concentration of atrazine or cyanazine in the presence of a fixed concentration of chlorpyrifos. It is possible that these herbicides may affect cytochrome P450 enzymes to confer synergistic effects on the toxicity of chlorpyrifos.

  11. Adsorption and desorption of atrazine and deethylatrazine by low organic carbon geologic materials

    USGS Publications Warehouse

    Roy, W.R.; Krapac, I.G.

    1994-01-01

    The adsorption and desorption of atrazine (2-chloro-4-ethylamino-6- isopropylamino-s-triazine) and a primary metabolite, deethylatrazine (2- amino-4-chloro-6-isopropylamino-s-triazine; DEA), by low organic C (??? 3.3 g kg-1) materials were measured by batch-equilibrium techniques. The adsorbents were samples of glacial outwash sand, till, and stream sediments. The adsorption of both atrazine and DEA conformed to linear isotherms. The adsorption of atrazine by most of the adsorbents yielded apparent K(oc) values that were in excess of those based on surface agricultural soils. Adsorption correlated with only the pH of the sand-water suspensions. The desorption of atrazine was hysteretic under the conditions of the measurement. DEA had a lower affinity for the same adsorbents; the mean ratio of K(d) values of DEA to those of atrazine was 0.37 ?? 0.20. DEA adsorption did not correlate with organic C, surface area, clay content of the adsorbents, or with the pH of the suspensions. DEA adsorption, unlike atrazine, tended to be reversible. There was a linear relationship between the adsorption constants of atrazine and those of DEA.

  12. 20 years of long-term atrazine monitoring in a shallow aquifer in western Germany.

    PubMed

    Vonberg, David; Vanderborght, Jan; Cremer, Nils; Pütz, Thomas; Herbst, Michael; Vereecken, Harry

    2014-03-01

    Atrazine was banned in Germany in 1991 due to findings of atrazine concentrations in ground- and drinking waters exceeding threshold values. Monitoring of atrazine concentrations in the groundwater since then provides information about the resilience of the groundwater quality to changing agricultural practices. In this study, we present results of a monitoring campaign of atrazine concentrations in the Zwischenscholle aquifer. This phreatic aquifer is exposed to intensive agricultural land use and susceptible to contaminants due to a shallow water table. In total 60 observation wells (OWs) have been monitored since 1991, of which 15 are sampled monthly today. Descriptive statistics of monitoring data were derived using the "regression on order statistics" (ROS) data censoring approach, estimating values for nondetects. The monitoring data shows that even 20 years after the ban of atrazine, the groundwater concentrations of sampled OWs remain on a level close to the threshold value of 0.1 μg l(-1) without any considerable decrease. The spatial distribution of atrazine concentrations is highly heterogeneous with OWs exhibiting permanently concentrations above the regulatory threshold on the one hand and OWs were concentrations are mostly below the limit of quantification (LOQ) on the other hand. A deethylatrazine-to-atrazine ratio (DAR) was used to distinguish between diffuse - and point-source contamination, with a global mean value of 0.84 indicating mainly diffuse contamination. Principle Component Analysis (PCA) of the monitoring dataset demonstrated relationships between the metabolite desisopropylatrazine, which was found to be exclusively associated with the parent compound simazine but not with atrazine, and between deethylatrazine, atrazine, nitrate, and the specific electrical conductivity. These parameters indicate agricultural impacts on groundwater quality. The findings presented in this study point at the difficulty to estimate mean concentrations

  13. Degradation of atrazine by UV/chlorine: Efficiency, influencing factors, and products.

    PubMed

    Kong, Xiujuan; Jiang, Jin; Ma, Jun; Yang, Yi; Liu, Weili; Liu, Yulei

    2016-03-01

    In this work, the degradation of atrazine by the combination of UV and chlorine (UV/chlorine) due to the formation of radicals during chlorine photolysis was systematically investigated in terms of efficiency, factors that influence the degradation kinetics, as well as oxidation products. It was found that the degradation efficiency of atrazine was enhanced by UV/chlorine compared to UV or chlorine alone. The degradation efficiency of atrazine was favorable at a lower pH, but was inhibited in the presence of natural organic matters. Meanwhile, the initial chlorine dosage, alkalinity, and chloride barely influenced the degradation efficiency under neutral pH conditions. The degradation of atrazine by UV/chlorine was inhibited in real waters (i.e., surface water and ground water) compared to in deionized water but was still more effective than UV alone. The oxidation products of atrazine resulting from de-alkylation, dechlorination-hydroxylation, alkylic-hydroxylation, alkylic-oxidation, alkylic-hydroxylation-dehydration, deamination-hydroxylation, and dechlorination-hydrogenation in UV/chlorine process were detected, which were slightly different from those formed in UV/H2O2 (commonly used UV-based advanced oxidation process). Particularly, the yields of three primary transformation products (desethyl-atrazine (DEA), desisopropyl-atrazine (DIA), and desethyl-desisopropyl-atrazine (DEIA)) were comparatively quantified in these two processes. The different trend of them formed in UV/chlorine system (DEA:DIA≈4) compared to that formed in UV/H2O2 system (DEA:DIA≈1) could be ascribed to the different reaction reactivities and mechanisms between HO• and Cl• with atrazine.

  14. 20 years of long-term atrazine monitoring in a shallow aquifer in western Germany.

    PubMed

    Vonberg, David; Vanderborght, Jan; Cremer, Nils; Pütz, Thomas; Herbst, Michael; Vereecken, Harry

    2014-03-01

    Atrazine was banned in Germany in 1991 due to findings of atrazine concentrations in ground- and drinking waters exceeding threshold values. Monitoring of atrazine concentrations in the groundwater since then provides information about the resilience of the groundwater quality to changing agricultural practices. In this study, we present results of a monitoring campaign of atrazine concentrations in the Zwischenscholle aquifer. This phreatic aquifer is exposed to intensive agricultural land use and susceptible to contaminants due to a shallow water table. In total 60 observation wells (OWs) have been monitored since 1991, of which 15 are sampled monthly today. Descriptive statistics of monitoring data were derived using the "regression on order statistics" (ROS) data censoring approach, estimating values for nondetects. The monitoring data shows that even 20 years after the ban of atrazine, the groundwater concentrations of sampled OWs remain on a level close to the threshold value of 0.1 μg l(-1) without any considerable decrease. The spatial distribution of atrazine concentrations is highly heterogeneous with OWs exhibiting permanently concentrations above the regulatory threshold on the one hand and OWs were concentrations are mostly below the limit of quantification (LOQ) on the other hand. A deethylatrazine-to-atrazine ratio (DAR) was used to distinguish between diffuse - and point-source contamination, with a global mean value of 0.84 indicating mainly diffuse contamination. Principle Component Analysis (PCA) of the monitoring dataset demonstrated relationships between the metabolite desisopropylatrazine, which was found to be exclusively associated with the parent compound simazine but not with atrazine, and between deethylatrazine, atrazine, nitrate, and the specific electrical conductivity. These parameters indicate agricultural impacts on groundwater quality. The findings presented in this study point at the difficulty to estimate mean concentrations

  15. [Effects of nitrogen and phosphorus fertilizer on atrazine degradation and detoxification by degrading strain HB-5].

    PubMed

    Su, Jun; Zhu, Lu-Sheng; Li, Xu-Hua; Wang, Jun; Xie, Hui; Wang, Jin-Hua; Wang, Qi; Jia, Wen-Tao

    2010-10-01

    An atrazine-degrading strain HB-5 was used as a bacteria for biodegradation. Treatments of soil with nitrogen single, phosphate single and nitrogen phosphate together with HB-5 were carried out for degradation and eco-toxicity test; then, relationship between atrazine degradation rate and soil available nitrogen, available phosphorus were discussed. Atrazine residues were determined by HPLC; available nitrogen was determined with alkaline hydrolysis diffusion method; available phosphorus was determined with 0.5 mol/L-NaHCO3 extraction and molybdenum stibium anti-color method, and toxicity test was carried out with micronucleus test of Vicia faba root tip cells. The results showed that: After separately or together application, nitrogenous and phosphorous fertilizers could significantly accelerate atrazine degradation than soil with HB-5 only. On day 5, the order of atrazine degradation was ANP > AP > AN > A; 7 days later, no statistically significant differences were found between treatments. The available nitrogen and phosphorus level in soil reduced as the degradation rate increased in the soil. The soil of eco-toxicity test results indicated that the eco-toxicity significantly reduced with the degradation of atrazine by HB-5, and the eco-toxicity on treatments of soil with fertilizer were all below the treatments without fertilizer. On day 5, the order of eco-toxicity was ANP < AP < AN < A; 7 days later, all treatments were decreased in control levels. So, adjusting soil nutrient content could not only promote atrazine degradation in soil but also could reduce the soil eco-toxicity effects that atrazine caused. All these results could be keystone of atrazine pollution remediation in contaminated soil in the future.

  16. Inhibitory effects of atrazine on Chlorella vulgaris as assessed by real-time polymerase chain reaction.

    PubMed

    Qian, Haifeng; Daniel Sheng, G; Liu, Weiping; Lu, Yingcong; Liu, Zhenghai; Fu, Zhengwei

    2008-01-01

    Atrazine, a highly toxic herbicide, is frequently detected in surface water because of its heavy application. Algae are among the aquatic organisms most susceptible to atrazine pollution in water. In the present study, the aquatic alga Chlorella vulgaris Beijerinck was chosen to assess the acute toxicity of atrazine (48-96 h) in terms of gene transcription and physiological changes. A real-time polymerase chain reaction (PCR) assay was used to quantify transcript levels of three photosystem genes in C. vulgaris. The diel patterns for regulation of the psaB (photosystem I reaction center protein subunit B), psbC (an integral membrane protein component of photosystem II), and rbcL (large subunit of ribulose-1,5-bisphosphate carboxylase oxygenase) gene transcripts were successfully quantified. Results showed that atrazine reduced the transcript abundances of three target genes and that the abundances decreased with increasing atrazine concentration. The determined smallest transcript levels of psaB, psbC, and rbcL, which occurred at the highest atrazine concentration tested (400 mug/L), were only 34.6, 34.6, and 8.1%, respectively, of the control sample value. Exposure to atrazine increased the level of malondialdehyde by 1.74-fold (the highest value) in C. vulgaris, suggesting potential oxidative damage to the alga. The activities of antioxidation enzymes (e.g., superoxide dismutase, peroxidase, and catalase) also increased markedly in the presence of atrazine, with maximum increases of 1.82-, 1.59-, and 2.31-fold, respectively. These elevated activities may help to alleviate the oxidative damage. Our results demonstrate that atrazine is highly toxic to this alga and that real-time PCR is an efficient technique for assessing the toxicity of xenobiotic compounds in algae.

  17. Survival and iono-regulatory performance in Atlantic salmon smolts is not affected by atrazine exposure.

    PubMed

    Matsumoto, Jacquie; Hosmer, Alan J; Van Der Kraak, Glen

    2010-09-01

    This study was conducted to determine the potential effects of atrazine exposure on survival and physiological performance in Atlantic salmon (Salmo salar) during the period of smoltification. This study involved two separate experiments in which juvenile Atlantic salmon were exposed to atrazine for a four day period in freshwater after which the fish were transferred to 50% seawater for two days and then to 100% seawater for five more days. The nominal concentrations of atrazine tested (1, 10 and 100 microg/L) were representative of and exceeded the levels measured in the North American freshwater environment. After seven days in seawater, fish were weighed, bled for the determination of plasma electrolyte levels, euthanized and samples collected for the determination of gonadosomatic index, muscle water content and gill Na+/K+-ATPase activity. Measured atrazine concentrations during the freshwater exposure period were 76-99% of nominal levels. There were no mortalities attributed to atrazine exposure. There were also no statistically significant differences in body weight, plasma sodium, potassium, magnesium and chloride levels, muscle water content or gill Na+/K+-ATPase activity between control and atrazine treated fish. Measurement of testis and ovary weights showed that there were no treatment effects on relative gonad size in male or female fish. These studies have shown that short term exposure to atrazine during the freshwater phase of their lifecycle had no effects on subsequent survival, body weight, relative gonad size or various measures of iono-regulatory performance in juvenile Atlantic salmon upon transfer to seawater. The concentrations of atrazine tested exceed those likely to be experienced in the natural aquatic environment suggesting that short term exposure to atrazine does not pose a risk to Atlantic salmon during the period of smoltification.

  18. Sorption and distribution of aged atrazine residues in the drainage system of an outdoor lysimeter experiment

    NASA Astrophysics Data System (ADS)

    Jablonowski, N. D.; Schäffer, A.; Burauel, P.

    2009-04-01

    Even though the environmental impact of the herbicide atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] is a matter of controversy, it is still extensively applied for agricultural purposes. Particularly in the US, atrazine has been applied to approximately 70% of all corn acreages in the last 18 years. Atrazine is banned in the EU but its use is increasing in countries like China, Brazil and India. Therefore, the worldwide soil burden of this compound must be enormous. Atrazine has been found to be highly persistent in the environment and it has been suggested that it is moderately mobile in the soil profile. As a result, it is found in most groundwater aquifers and surface waters in agricultural areas in the US. Even in Germany, where it was prohibited in 1991, it is still found in groundwater wells below agriculturally used land where it was formerly applied. For a long-term outdoor lysimeter experiment with a disturbed soil column, a drainage system of fine gravel was originally embedded at the bottom of the lysimeter. In this drainage system, atrazine and its metabolite 2-hydroxy-atrazine were extracted as long as 22 years after the last atrazine application. Due to the radiolabelling, the spatial distribution of the atrazine residues can be evaluated in fractions like fine clay particles attached to the gravel or in the gravel itself. Approximately 2% of the total gravel consisted of carbonaceous, slag-like particles which might retain most of the atrazine and its residues. The latest data will be presented at the session.

  19. Atrazine remediation in agricultural infiltrate by bioaugmented polyvinyl alcohol immobilized and free Agrobacterium radiobacter J14a.

    PubMed

    Siripattanakul, Sumana; Wirojanagud, Wanpen; McEvoy, John M; Casey, Francis X M; Khan, Eakalak

    2008-01-01

    Bench-scale sand column breakthrough experiments were conducted to examine atrazine remediation in agricultural infiltrate by Agrobacterium radiobacter J14a (J14a) immobilized in phosphorylated-polyvinyl alcohol compared to free J14a cells. The effects of cell loading and infiltration rate on atrazine degradation and the loss of J14a were investigated. Four sets of experiments, i) tracers, ii) immobilized dead cells, iii) immobilized cells, and iv) free cells, were performed. The atrazine bioremediation at the cell loadings of 300, 600, and 900 mg dry cells l(-1) and the infiltration rates of 1, 3, and 6 cm d(-1) were tested for 5 column pore volumes (PV). The atrazine breakthrough results indicated that the immobilized dead cells significantly retarded atrazine transport. The atrazine removal efficiencies at the infiltration rates of 1, 3, and 6 cm d(-1) were 100%, 80-97%, and 50-70% respectively. Atrazine remediation capacity for the immobilized cells was not significantly different from the free cells. Both infiltration rate and cell loading significantly affected atrazine removal for both cell systems. The bacterial loss from the immobilized cell system was 10 to 100 times less than that from the free cell system. For long-term tests at 50 PV, the immobilized cell system provided consistent atrazine removal efficiency while the atrazine removal by the free cells declined gradually because of the cell loss.

  20. in-silico analysis suggests alterations in the function of XisA protein as a possible mechanism of butachlor toxicity in the nitrogen fixing cyanobacterium Anabaena sp. PCC 7120

    PubMed Central

    Singh, Shilpi; Singh, Prem Pal

    2013-01-01

    Butachlor, a commonly used herbicide adversely affects the nitrogen fixing capability of Anabaena, an acclaimed nitrogen fixer in the Indian paddy fields. The nitrogen fixation in Anabaena is triggered by the excision of nifD element by xisA gene leading to rearrangement of nifD forming nifHDK operon in the heterocyst of Anabaena sp. PCC7120. Functional elucidation adjudged through in-silico analysis revealed that xisA belongs to integrase family of tyrosine recombinase. The predicted functional partners with XisA protein that have shown cooccurence with this protein in a network are mainly hypothetical proteins with unknown functions except psaK1 whose exact function in photosystem I is not yet known. The focus of this study was to find out the relation between XisA and butachlor using in-silico approaches. The XisA protein was modeled and its active sites were identified. Docking studies revealed that butachlor binds at the active site of XisA protein hampering its excision ability vis-à-vis nif genes in Anabaena sp. PCC7120. This study reveals that butachlor is not directly involved in hampering the nitrogen fixing ability of Anabaena sp. PCC7120 but by arresting the excision ability of XisA protein necessary for the functioning of nif gene and nitrogen fixation. PMID:23930023

  1. in-silico analysis suggests alterations in the function of XisA protein as a possible mechanism of butachlor toxicity in the nitrogen fixing cyanobacterium Anabaena sp. PCC 7120.

    PubMed

    Singh, Shilpi; Singh, Prem Pal

    2013-01-01

    Butachlor, a commonly used herbicide adversely affects the nitrogen fixing capability of Anabaena, an acclaimed nitrogen fixer in the Indian paddy fields. The nitrogen fixation in Anabaena is triggered by the excision of nifD element by xisA gene leading to rearrangement of nifD forming nifHDK operon in the heterocyst of Anabaena sp. PCC7120. Functional elucidation adjudged through in-silico analysis revealed that xisA belongs to integrase family of tyrosine recombinase. The predicted functional partners with XisA protein that have shown cooccurence with this protein in a network are mainly hypothetical proteins with unknown functions except psaK1 whose exact function in photosystem I is not yet known. The focus of this study was to find out the relation between XisA and butachlor using in-silico approaches. The XisA protein was modeled and its active sites were identified. Docking studies revealed that butachlor binds at the active site of XisA protein hampering its excision ability vis-à-vis nif genes in Anabaena sp. PCC7120. This study reveals that butachlor is not directly involved in hampering the nitrogen fixing ability of Anabaena sp. PCC7120 but by arresting the excision ability of XisA protein necessary for the functioning of nif gene and nitrogen fixation.

  2. in-silico analysis suggests alterations in the function of XisA protein as a possible mechanism of butachlor toxicity in the nitrogen fixing cyanobacterium Anabaena sp. PCC 7120.

    PubMed

    Singh, Shilpi; Singh, Prem Pal

    2013-01-01

    Butachlor, a commonly used herbicide adversely affects the nitrogen fixing capability of Anabaena, an acclaimed nitrogen fixer in the Indian paddy fields. The nitrogen fixation in Anabaena is triggered by the excision of nifD element by xisA gene leading to rearrangement of nifD forming nifHDK operon in the heterocyst of Anabaena sp. PCC7120. Functional elucidation adjudged through in-silico analysis revealed that xisA belongs to integrase family of tyrosine recombinase. The predicted functional partners with XisA protein that have shown cooccurence with this protein in a network are mainly hypothetical proteins with unknown functions except psaK1 whose exact function in photosystem I is not yet known. The focus of this study was to find out the relation between XisA and butachlor using in-silico approaches. The XisA protein was modeled and its active sites were identified. Docking studies revealed that butachlor binds at the active site of XisA protein hampering its excision ability vis-à-vis nif genes in Anabaena sp. PCC7120. This study reveals that butachlor is not directly involved in hampering the nitrogen fixing ability of Anabaena sp. PCC7120 but by arresting the excision ability of XisA protein necessary for the functioning of nif gene and nitrogen fixation. PMID:23930023

  3. Characterization of bacterial diversity in an atrazine degrading enrichment culture and degradation of atrazine, cyanuric acid and biuret in industrial wastewater.

    PubMed

    Dutta, Anirban; Vasudevan, Venugopal; Nain, Lata; Singh, Neera

    2016-01-01

    An enrichment culture was used to study atrazine degradation in mineral salt medium (MSM) (T1), MSM+soil extract (1:1, v/v) (T2) and soil extract (T3). Results suggested that enrichment culture required soil extract to degrade atrazine, as after second sequential transfer only partial atrazine degradation was observed in T1 treatment while atrazine was completely degraded in T2 and T3 treatments even after fourth transfer. Culture independent polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique confirmed selective enrichment of genus Bacillus along with Pseudomonas and Burkholderia. Degradation of atrazine/metabolites in the industrial wastewater was studied at different initial concentrations of the contaminants [wastewater-water (v/v) ratio: T1, 1:9; T2, 2:8; T3, 3:7; T4, 5:5 and T5, undiluted effluent]. The initial concentrations of atrazine, cyanuric acid and biuret ranged between 5.32 and 53.92 µg mL(-1), 265.6 and 1805.2 µg mL(-1) and 1.85 and 16.12 µg mL(-1), respectively. The enrichment culture was able to completely degrade atrazine, cyanuric acid and biuret up to T4 treatment, while no appreciable degradation of contaminants was observed in the undiluted effluent (T5). Inability of enrichment culture to degrade atrazine/metabolites might be due to high concentrations of cyanuric acid. Therefore, a separate study on cyanuric acid degradation suggested: (i) no appreciable cyanuric acid degradation with accumulation of an unidentified metabolite in the medium where cyanuric acid was supplemented as the sole source of carbon and nitrogen; (ii) partial cyanuric acid degradation with accumulation of unidentified metabolite in the medium containing additional nitrogen source; and (iii) complete cyanuric acid degradation in the medium supplemented with an additional carbon source. This unidentified metabolite observed during cyanuric acid degradation and also detected in the enrichment culture inoculated wastewater samples

  4. Characterization of bacterial diversity in an atrazine degrading enrichment culture and degradation of atrazine, cyanuric acid and biuret in industrial wastewater.

    PubMed

    Dutta, Anirban; Vasudevan, Venugopal; Nain, Lata; Singh, Neera

    2016-01-01

    An enrichment culture was used to study atrazine degradation in mineral salt medium (MSM) (T1), MSM+soil extract (1:1, v/v) (T2) and soil extract (T3). Results suggested that enrichment culture required soil extract to degrade atrazine, as after second sequential transfer only partial atrazine degradation was observed in T1 treatment while atrazine was completely degraded in T2 and T3 treatments even after fourth transfer. Culture independent polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique confirmed selective enrichment of genus Bacillus along with Pseudomonas and Burkholderia. Degradation of atrazine/metabolites in the industrial wastewater was studied at different initial concentrations of the contaminants [wastewater-water (v/v) ratio: T1, 1:9; T2, 2:8; T3, 3:7; T4, 5:5 and T5, undiluted effluent]. The initial concentrations of atrazine, cyanuric acid and biuret ranged between 5.32 and 53.92 µg mL(-1), 265.6 and 1805.2 µg mL(-1) and 1.85 and 16.12 µg mL(-1), respectively. The enrichment culture was able to completely degrade atrazine, cyanuric acid and biuret up to T4 treatment, while no appreciable degradation of contaminants was observed in the undiluted effluent (T5). Inability of enrichment culture to degrade atrazine/metabolites might be due to high concentrations of cyanuric acid. Therefore, a separate study on cyanuric acid degradation suggested: (i) no appreciable cyanuric acid degradation with accumulation of an unidentified metabolite in the medium where cyanuric acid was supplemented as the sole source of carbon and nitrogen; (ii) partial cyanuric acid degradation with accumulation of unidentified metabolite in the medium containing additional nitrogen source; and (iii) complete cyanuric acid degradation in the medium supplemented with an additional carbon source. This unidentified metabolite observed during cyanuric acid degradation and also detected in the enrichment culture inoculated wastewater samples

  5. Comparison of rat olfactory mucosal responses to carcinogenic and non-carcinogenic chloracetanilides

    PubMed Central

    Genter, M.B.; Warner, B.M.; Medvedovic, M.; Sartor, M.A.

    2009-01-01

    Alachlor and butachlor are chloracetanilide herbicides that induce olfactory tumors in rats, whereas propachlor does not. The mechanism by which alachlor induces tumors is distinct from many other nasal carcinogens, in that alachlor induces a gradual de-differentiation of the olfactory mucosa (OM) to a more respiratory-like epithelium, in contrast to other agents that induce cytotoxicity, followed by an aberrant regenerative response. We studied biochemical and genomic effects of these compounds to identify processes that occur in common between alachlor- and butachlor-treated rats. Because we have previously shown that matrix metalloproteinase-2 (MMP2) is activated in OM by alachlor, in the present studies we evaluated both MMP2 activation and changes in OM gene expression in response to carcinogenic and non-carcinogenic chloracetanilide treatments. All three chloracetanilides activated MMP2, and > 300 genes were significantly up- or downregulated between control and alachlor-treated rats. The most significantly regulated gene was vomeromodulin, which was dramatically upregulated by alachlor and butachlor treatment (>60-fold), but not by propachlor treatment. Except for similar gene responses in alachlor- and butachlor-treated rats, we did not identify clear-cut differences that would predict OM carcinogenicity in this study. PMID:19425180

  6. INFILTRATION OF ATRAZINE AND METABOLOTES FROM A STREAM TO AN ALLUVIAL AQUIFER

    EPA Science Inventory

    The infiltration of atrazine, deethylatrazine, and deisopropylatrazine from Walnut Creek, a tributary stream, to the alluvial valley aquifer along the South Skunk River in central Iowa occurred where the stream transects the river's flood plain. A preliminary estimate indicated t...

  7. Performance evaluation of waste activated carbon on atrazine removal from contaminated water.

    PubMed

    Ghosh, Pranab Kumar; Philip, Ligy

    2005-01-01

    In this study, the potential of spent activated carbon from water purifier (Aqua Guard, India) for the removal of atrazine (2 chloro-4 ethylamino-6-isopropylamino-1, 3, 5 triazine) from wastewaters was evaluated. Different grades of spent activated carbon were prepared by various pretreatments. Based on kinetic and equilibrium study results, spent activated carbon with a grain size of 0.3-0.5 mm and washed with distilled water (designated as WAC) was selected for fixed column studies. Batch adsorption equilibrium data followed both Freundlich and Langmuir isotherm. Fixed bed adsorption column with spent activated carbon as adsorbent was used as a polishing unit for the removal of atrazine from the effluent of an upflow anaerobic sludge blanket (UASB) reactor treating atrazine bearing domestic wastewater. Growth of bacteria on the surface of WAC was observed during column study and bacterial activity enhanced the effectiveness of adsorbent on atrazine removal from wastewater. PMID:15913015

  8. Potiential role of the adrenal axis on the reproductive effects of Atrazine

    EPA Science Inventory

    We and others reported that atrazine (ATR) disrupts the regulation of the ovulatory luteinizing hormone (LH) surge and the hormonal control of other reproductive functions in the rat. In addition, administration of ATR or the intermediate metabolite deisopropylatrazine (DIA) stim...

  9. European Union bans atrazine, while the United States negotiates continued use.

    PubMed

    Sass, Jennifer Beth; Colangelo, Aaron

    2006-01-01

    Atrazine is a common agricultural herbicide with endocrine disruptor activity. There is evidence that it interferes with reproduction and development, and may cause cancer. Although the U.S. Environmental Protection Agency (EPA) approved its continued use in October 2003, that same month the European Union (EU) announced a ban of atrazine because of ubiquitous and unpreventable water contamination. The authors reviewed regulatory procedures and government documents, and report efforts by the manufacturer of atrazine, Syngenta, to influence the U.S. atrazine assessment, by submitting flawed scientific data as evidence of no harm, and by meeting repeatedly and privately with EPA to negotiate the government's regulatory approach. Many of the details of these negotiations continue to be withheld from the public, despite EPA regulations and federal open-government laws that require such decisions to be made in the open. PMID:16967834

  10. European Union bans atrazine, while the United States negotiates continued use.

    PubMed

    Sass, Jennifer Beth; Colangelo, Aaron

    2006-01-01

    Atrazine is a common agricultural herbicide with endocrine disruptor activity. There is evidence that it interferes with reproduction and development, and may cause cancer. Although the U.S. Environmental Protection Agency (EPA) approved its continued use in October 2003, that same month the European Union (EU) announced a ban of atrazine because of ubiquitous and unpreventable water contamination. The authors reviewed regulatory procedures and government documents, and report efforts by the manufacturer of atrazine, Syngenta, to influence the U.S. atrazine assessment, by submitting flawed scientific data as evidence of no harm, and by meeting repeatedly and privately with EPA to negotiate the government's regulatory approach. Many of the details of these negotiations continue to be withheld from the public, despite EPA regulations and federal open-government laws that require such decisions to be made in the open.

  11. Determination of growth rate depression of some green algae by atrazine

    SciTech Connect

    Hersh, C.M.; Crumpton, W.G.

    1987-12-01

    A common contaminant of surface waters of agricultural regions is the triazine herbicide, atrazine (2-chloro-4-ethylamino-6-isoproplyamino-s-triazine). Atrazine effectively inhibits growth and photosynthesis of most plants, including freshwater algae. Both depression of growth rate and reduced yield have been used as parameters in studies of the effects of atrazine on algal growth. Considerable variation exists among algal toxicity methods despite attempts at standardization. Experimental endpoints range from percent inhibitions to EC50s. Algae from two different Iowa springs were the subjects of a study of naturally occurring atrazine tolerance. The authors report here the results of two aspects of that study: development of a quick method of assessing toxin effects on algal growth, and investigation of a ecologically meaningful endpoint for toxin-growth experiments.

  12. Chlamydomonas reinhardtii cells adjust the metabolism to maintain viability in response to atrazine stress.

    PubMed

    Esperanza, Marta; Seoane, Marta; Rioboo, Carmen; Herrero, Concepción; Cid, Ángeles

    2015-08-01

    Chlamydomonas reinhardtii cells were exposed to a sublethal concentration of the widespread herbicide atrazine for 3 and 24h. Physiological parameters related to cellular energy status, such as cellular activity and mitochondrial and cytoplasmic membrane potentials, monitored by flow cytometry, were altered in microalgal cells exposed to 0.25μM of atrazine. Transcriptomic analyses, carried out by RNA-Seq technique, displayed 12 differentially expressed genes between control cultures and atrazine-exposed cultures at both tested times. Many cellular processes were affected, but the most significant changes were observed in genes implicated in amino acid catabolism and respiratory cellular process. Obtained results suggest that photosynthesis inhibition by atrazine leads cells to get energy through a heterotrophic metabolism to maintain their viability.

  13. Characterization of an atrazine molecularly imprinted polymer prepared by a cooling method

    NASA Astrophysics Data System (ADS)

    Royani, Idha; Widayani, Abdullah, Mikrajuddin; Khairurrijal

    2014-03-01

    A molecularly imprinted polymer (MIP) for atrazine was successfully prepared. Atrazine molecules as templates were incorporated into the pre-polymerization solution containing a functional monomer (methacrylic acid), a cross-linker (ethylene glycol dimethacrylate), and an initiator (benzoyl peroxide). The placement of a tube containing the pre-polymerization solution into a freezer was done to replace nitrogen pouring into the pre-polymerization solution. The sensing characteristic of the obtained MIP was examined and it was found that the amount of atrazine bound to the cavities in the MIP increases with increasing the initial concentration of atrazine. From Scatchard plots, it was found that the equilibrium dissociation constant KD and the apparent maximum number of binding sites Bmax, which are written as (KD, Bmax), are (6.4 μM, 13.41 mmol/g) and (6.5 μM, 4.55 mmol/g) for the 10 and 30 mg of MIP, respectively.

  14. Effect of Nrf2 on rat ovarian tissues against atrazine-induced anti-oxidative response.

    PubMed

    Zhao, Fan; Li, Kun; Zhao, Lijing; Liu, Jian; Suo, Qi; Zhao, Jing; Wang, Hebin; Zhao, Shuhua

    2014-01-01

    The environmental persistence and bioaccumulation of herbicide atrazine may pose a significant threat to human health. In this experiment, Wistar rats were treated by 5, 25 and 125 mg·kg(-1) atrazine respectively for 28 days, and the oxidative stress responses as well as the activations of Nrf2 signaling pathway in ovarian tissues induced by atrazine were observed. The results showed that after be treated by atrazine, the proportion of atretic follicles in the rat ovary were increased, the contents of NO and MDA in the tissue homogenates were increased, the over-expressed Nrf2 transferred into the nuclei and played an antioxidant role by up-regulated the expression of II phase detoxifying enzymes such as HO1 and NQO1 and the expression of antioxidant enzymes such as CAT, SOD and GSH-PX.

  15. Effects of atrazine on DNA damage and antioxidative enzymes in Vicia faba.

    PubMed

    Song, Yan; Zhu, Lu-Sheng; Xie, Hui; Wang, Jun; Wang, Jin-Hua; Liu, Wei; Dong, Xiao-Li

    2009-05-01

    To evaluate atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) ecotoxicology in soil, the effect of atrazine on the activity of antioxidative enzymes (superoxide dismutase [SOD], catalase [CAT], and guaiacol peroxidase [POD]) was investigated in Vicia faba roots. Tissues from each treatment were collected on the days 7, 14, 21, and 28. Compared with the controls, SOD activity in V. faba roots was stimulated by the 2.5 mg/kg treatment and inhibited by the 5 and 10 mg/kg treatments, and CAT and POD activities in the 10 mg/kg treatment were inhibited on the whole. The Olive tail moments of single-cell gel electrophoresis of root cells were enhanced after treatment with different doses of atrazine on days 7, 14, 21, and 28, and significant differences were found compared to the controls. In conclusion, atrazine induces oxidative stress and DNA damage on V. faba.

  16. A SCREENING-LEVEL MODEL EVALUATION OF ATRAZINE IN THE LAKE MICHIGAN BASIN

    EPA Science Inventory

    Atrazine, a widely used herbicide in the agricultural regions of the Lake Michigan basin, was selected as a priority toxic chemical study in the United States Environmental Protection Agency (U.S. EPA) - sponsored Lake Michigan Mass Balance Project.

  17. Phytotoxicity assessment of atrazine on growth and physiology of three emergent plants.

    PubMed

    Wang, Qinghai; Que, Xiaoe; Zheng, Ruilun; Pang, Zuo; Li, Cui; Xiao, Bo

    2015-07-01

    The emergent plants Acorus calamus, Lythrum salicaria, and Scirpus tabernaemontani were exposed to atrazine for 15, 30, 45, and 60 days in a hydroponic system. Effects were evaluated investigating plant growth, chlorophyll (Chl) content, peroxidase (POD) activity, and malondialdehyde (MDA) content. Results showed that selected plants survived in culture solution with atrazine ≤8 mg L(-1), but relative growth rates decreased significantly in the first 15-day exposure. Chla content decreased, but MDA increased with increasing atrazine concentration. S. tabernaemontani was the most insensitive species, followed by A. calamus and L.salicaria. The growth indicators exhibited significant changes in the early stage of atrazine exposure; subsequently, the negative impacts weakened and disappeared. Plant growth may be more representative of emergent plant fitness than physiological endpoints in toxicity assessment of herbicides to emergent plants.

  18. Effective photocatalytic degradation of atrazine over titania-coated carbon nanotubes (CNTs) coupled with microwave energy.

    PubMed

    Chen, Hongzhe; Yang, Shaogui; Yu, Kai; Ju, Yongming; Sun, Cheng

    2011-04-14

    Microwave-assisted photocatalytic (MAPC) degradation of atrazine over nanotitania coated multiwalled carbon nanotubes (TiO(2)/MWCNTs) was investigated in this study. As a result, degradation efficiency of atrazine over TiO(2)/CNTs prepared by hydrothermal method was about 30% and 20% higher than that of titania P25 and anatase prepared hydrothermally in given time. The TiO(2)/CNTs composite samples were characterized by TGA-DSC, TEM, UV-vis DRS, XRD and BET, to explain the reason for efficient degradation and adsorption process of atrazine. Microwave thermal effect in this process was also investigated. Intermediates of degradation both in MAPC process and microwave-assisted photodegradation (MAPD) process were identified by LC/MS. It suggests that MWCNTs have special effects on atrazine degradation during MAPC process, like strong microwave absorption capability.

  19. Summer cover crops reduce atrazine leaching to shallow groundwater in southern Florida.

    PubMed

    Potter, Thomas L; Bosch, David D; Joo, Hyun; Schaffer, Bruce; Muñoz-Carpena, Rafael

    2007-01-01

    At Florida's southeastern tip, sweet corn (Zea Mays) is grown commercially during winter months. Most fields are treated with atrazine (6-chloro-N-ethyl-N'-[1-methylethyl]-1,3,5-triazine-2,4-diamine). Hydrogeologic conditions indicate a potential for shallow groundwater contamination. This was investigated by measuring the parent compound and three degradates--DEA (6-chloro-N-[1-methylethyl]-1,3,5-triazine-2,4-diamine), DIA (6-chloro-N-ethyl)-1,3,5-triazine-2,4-diamine, and HA (6-hydroxy-N-[1-methylethyl]-1,3,5-triazine-2,4-diamine)--in water samples collected beneath sweet corn plots treated annually with the herbicide. During the study, a potential mitigation measure (i.e., the use of a cover crop, Sunn Hemp [Crotalaria juncea L.], during summer fallow periods followed by chopping and turning the crop into soil before planting the next crop) was evaluated. Over 3.5 yr and production of four corn crops, groundwater monitoring indicated leaching of atrazine, DIA, and DEA, with DEA accounting for more than half of all residues in most samples. Predominance of DEA, which increased after the second atrazine application, was interpreted as an indication of rapid and extensive atrazine degradation in soil and indicated that an adapted community of atrazine degrading organisms had developed. A companion laboratory study found a sixfold increase in atrazine degradation rate in soil after three applications. Groundwater data also revealed that atrazine and degradates concentrations were significantly lower in samples collected beneath cover crop plots when compared with concentrations below fallow plots. Together, these findings demonstrated a relatively small although potentially significant risk for leaching of atrazine and its dealkylated degradates to groundwater and that the use of a cover crop like Sunn Hemp during summer months may be an effective mitigation measure.

  20. Photocatalytic degradation of atrazine using TiO{sub 2}-impregnated mesh

    SciTech Connect

    Kiserow, D.J.; Pugh, K.C.

    1994-10-01

    TiO{sub 2} photocatalysis is investigated is a potential means for the disposal of pesticide rinsate waste at agrochemical dealerships. The focus is an evaluation of parameters that affect the rate and mechanism of atrazine degradation using formulated atrazine (ca. 20-25 ppm), TiO{sub 2} mesh, a high-pressure mercury-vapor lamp, and solar irradiation. The UV transmission of a variety of transparent materials was measured and atrazine photocatalysis was carried out using several materials as reactor covers. The pseudo-first-order rate constants were calculated and compared to determine which cover results in the most efficient atrazine degradation. A clear acrylic gave results nearly identical to Pyrex and was chosen for future photocatalytic experiments. UV intensity and photocatalytic rate were studied as a function of different numbers of layers of TiO{sub 2} mesh. It was found that five layers give the optimum rate of degradation without employing excess mesh. In order to assess the general effect of impurities present in water on the rate of atrazine degradation, water from five different sources was obtained and each sample was analyzed for purity and used to prepare aqueous atrazine for photocatalytic degradation. The results show that contaminants specific to different locations are likely to inhibit the rate of photocatalysis to different degrees. While working to maximize the rate of atrazine degradation, studies are concurrently in progress to elucidate the mechanism of degradation for the experimental conditions employed herein. Initial results indicate that the overall degradation of atrazine to the reported end product, cyanuric acid, occurs by two distinct pathways of similar importance.

  1. Demasculinization and feminization of male gonads by atrazine: Consistent effects across vertebrate classes

    PubMed Central

    Hayes, Tyrone B.; Anderson, Lloyd L.; Beasley, Val R.; de Solla, Shane R.; Iguchi, Taisen; Ingraham, Holly; Kestemont, Patrick; Kniewald, Jasna; Kniewald, Zlatko; Langlois, Valerie S.; Luque, Enrique H.; McCoy, Krista A.; Muñoz-de-Toro, Mónica; Oka, Tomohiro; Oliveira, Cleida A.; Orton, Frances; Ruby, Sylvia; Suzawa, Miyuki; Tavera-Mendoza, Luz E.; Trudeau, Vance L.; Victor-Costa, Anna Bolivar; Willingham, Emily

    2015-01-01

    Atrazine is the most commonly detected pesticide contaminant of ground water, surface water, and precipitation. Atrazine is also an endocrine disruptor that, among other effects, alters male reproductive tissues when animals are exposed during development. Here, we apply the nine so-called “Hill criteria” (Strength, Consistency, Specificity, Temporality, Biological Gradient, Plausibility, Coherence, Experiment, and Analogy) for establishing cause–effect relationships to examine the evidence for atrazine as an endocrine disruptor that demasculinizes and feminizes the gonads of male vertebrates. We present experimental evidence that the effects of atrazine on male development are consistent across all vertebrate classes examined and we present a state of the art summary of the mechanisms by which atrazine acts as an endocrine disruptor to produce these effects. Atrazine demasculinizes male gonads producing testicular lesions associated with reduced germ cell numbers in teleost fish, amphibians, reptiles, and mammals, and induces partial and/or complete feminization in fish, amphibians, and reptiles. These effects are strong (statistically significant), consistent across vertebrate classes, and specific. Reductions in androgen levels and the induction of estrogen synthesis – demonstrated in fish, amphibians, reptiles, and mammals – represent plausible and coherent mechanisms that explain these effects. Biological gradients are observed in several of the cited studies, although threshold doses and patterns vary among species. Given that the effects on the male gonads described in all of these experimental studies occurred only after atrazine exposure, temporality is also met here. Thus the case for atrazine as an endocrine disruptor that demasculinizes and feminizes male vertebrates meets all nine of the “Hill criteria”. PMID:21419222

  2. Menstrual cycle characteristics and reproductive hormone levels in women exposed to atrazine in drinking water.

    PubMed

    Cragin, Lori A; Kesner, James S; Bachand, Annette M; Barr, Dana Boyd; Meadows, Juliana W; Krieg, Edward F; Reif, John S

    2011-11-01

    Atrazine is the most commonly used herbicide in the U.S. and a wide-spread groundwater contaminant. Epidemiologic and laboratory evidence exists that atrazine disrupts reproductive health and hormone secretion. We examined the relationship between exposure to atrazine in drinking water and menstrual cycle function including reproductive hormone levels. Women 18-40 years old residing in agricultural communities where atrazine is used extensively (Illinois) and sparingly (Vermont) answered a questionnaire (n=102), maintained menstrual cycle diaries (n=67), and provided daily urine samples for analyses of luteinizing hormone (LH), and estradiol and progesterone metabolites (n=35). Markers of exposures included state of residence, atrazine and chlorotriazine concentrations in tap water, municipal water and urine, and estimated dose from water consumption. Women who lived in Illinois were more likely to report menstrual cycle length irregularity (odds ratio (OR)=4.69; 95% confidence interval (CI): 1.58-13.95) and more than 6 weeks between periods (OR=6.16; 95% CI: 1.29-29.38) than those who lived in Vermont. Consumption of >2 cups of unfiltered Illinois water daily was associated with increased risk of irregular periods (OR=5.73; 95% CI: 1.58-20.77). Estimated "dose" of atrazine and chlorotriazine from tap water was inversely related to mean mid-luteal estradiol metabolite. Atrazine "dose" from municipal concentrations was directly related to follicular phase length and inversely related to mean mid-luteal progesterone metabolite levels. We present preliminary evidence that atrazine exposure, at levels below the US EPA MCL, is associated with increased menstrual cycle irregularity, longer follicular phases, and decreased levels of menstrual cycle endocrine biomarkers of infertile ovulatory cycles.

  3. Prediction of the Fate and Transport Processes of Atrazine in a Reservoir

    NASA Astrophysics Data System (ADS)

    Chung, Se-Woong; Gu, Roy R.

    2009-07-01

    The fate and transport processes of a toxic chemical such as atrazine, an herbicide, in a reservoir are significantly influenced by hydrodynamic regimes of the reservoir. The two-dimensional (2D) laterally-integrated hydrodynamics and mass transport model, CE-QUAL-W2, was enhanced by incorporating a submodel for toxic contaminants and applied to Saylorville Reservoir, Iowa. The submodel describes the physical, chemical, and biological processes and predicts unsteady vertical and longitudinal distributions of a toxic chemical. The simulation results from the enhanced 2D reservoir model were validated by measured temperatures and atrazine concentrations in the reservoir. Although a strong thermal stratification was not identified from both observed and predicted water temperatures, the spatial variation of atrazine concentrations was largely affected by seasonal flow circulation patterns in the reservoir. In particular, the results showed the effect of flow circulation on spatial distribution of atrazine during summer months as the river flow formed an underflow within the reservoir and resulted in greater concentrations near the surface of the reservoir. Atrazine concentrations in the reservoir peaked around the end of May and early June. A good agreement between predicted and observed times and magnitudes of peak concentrations was obtained. The use of time-variable decay rates of atrazine led to more accurate prediction of atrazine concentrations, while the use of a constant half-life (60 days) over the entire period resulted in a 40% overestimation of peak concentrations. The results provide a better understanding of the fate and transport of atrazine in the reservoir and information useful in the development of reservoir operation strategies with respect to timing, amount, and depth of withdrawal.

  4. Chemical fate and transport of atrazine in soil gravel materials at agrichemical distribution facilities

    USGS Publications Warehouse

    Roy, W.R.; Krapac, I.G.; Chou, S.-F.J.

    1999-01-01

    The gravel commonly used to cover parking lots and roadways at retail agrichemical facilities may contain relatively large concentrations of pesticides that resulted from past management problems. These pesticides may threaten groundwater quality. Previous studies, however, suggested that the pesticides had not moved from the gravel in several sample profiles. Excavations at a closed facility revealed tremendous variability in pesticide distribution within the site. Pesticides were present below the gravel in two profiles, but the mechanism(s) for their movement were not clear. The objectives of this study were to investigate how the physical and chemical properties of the gravel influence the environmental fate of atrazine. All of the gravel samples collected and characterized contained atrazine and sufficient organic C to adsorb significant amounts of atrazine, thus retarding its movement through the gravel. Laboratory column leaching experiments, however, suggested that much of the atrazine should leach from the gravel within a year or two. A field-scale test plot was constructed to study how atrazine moves through the gravel under controlled conditions. Atrazine was "spilled" in the test plot. Atrazine moved from the gravel both vertically and horizontally. It appears that formulated product spilled on gravel will leach. A single discrete spill can give rise to phantom spills whose occurrence and distribution is not related to any specific pesticide-management practice. The apparent lack of atrazine leaching from gravel appeared to be a transient phenomenon and/or the result of sampling limitations in previous studies. The contaminated gravel clearly poses a risk to groundwater quality.

  5. Atrazine concentrations, gonadal gross morphology and histology in ranid frogs collected in Michigan agricultural areas.

    PubMed

    Murphy, M B; Hecker, M; Coady, K K; Tompsett, A R; Jones, P D; Du Preez, L H; Everson, G J; Solomon, K R; Carr, J A; Smith, E E; Kendall, R J; Van Der Kraak, G; Giesy, J P

    2006-03-10

    The triazine herbicide atrazine has been suggested to be a potential disruptor of normal sexual development in male frogs. The goals of this study were to collect native ranid frogs from sites in agricultural and non-agricultural areas and determine whether hypothesised atrazine effects on the gonads could be observed at the gross morphological and histological levels. Juvenile and adult green frogs (Rana clamitans), bullfrogs (R. catesbeiana) and leopard frogs (R. pipiens) were collected in the summers of 2002 and 2003. Atrazine concentrations were below the limit of quantification at non-agricultural sites, and concentrations did not exceed 2 microg/L at most agricultural sites. One concentration greater than 200 microg atrazine/L was measured once at one site in 2002. Hermaphroditic individuals with both male and female gonad tissue in either one or both gonads, were found at a low incidence at both non-agricultural and agricultural sites, and in both adults and juveniles. Testicular oocytes (TO) were found in male frogs at most of the sites, with the greatest incidence occurring in juvenile leopard frogs. TO incidence was not significantly different between agricultural and non-agricultural sites with the exception of juveniles collected in 2003. Atrazine concentrations were not significantly correlated with the incidence of hermaphroditism, but maximum atrazine concentrations were correlated with TO incidence in juvenile frogs in 2003. However, given the lack of a consistent relationship between atrazine concentrations and TO incidence, it is more likely the TOs observed in this study result from natural processes in development rather than atrazine exposure.

  6. Atrazine Acts as an Endocrine Disrupter by Inhibiting cAMP-specific Phosphodiesterase-4

    PubMed Central

    Kucka, Marek; Pogrmic-Majkic, Kristina; Fa, Svetlana; Stojilkovic, Stanko S.; Kovacevic, Radmila

    2014-01-01

    Atrazine, one of the most commonly used herbicides worldwide, acts as an endocrine disruptor, but the mechanism of its action has not been characterized. In this study, we show that atrazine rapidly increases cAMP levels in cultured rat pituitary and testicular Leydig cells in a concentration-dependent manner, but less effectively than 3-isobutyl-1-methylxanthine, a competitive non-specific inhibitor of phosphodiesterases (PDEs). In forskolin (an activator of adenylyl cyclase)- and probenecid (an inhibitor of cyclic nucleotide transporters)-treated cells, but not in 3-isobutyl-1-methylxanthine-treated cells, atrazine further increased cAMP levels, indicating that inhibition of PDEs accounts for accumulation of cAMP. In contrast to cAMP, atrazine did not alter cGMP levels, further indicating that it inhibits cAMP-specific PDEs. Atrazine-induced changes in cAMP levels were sufficient to stimulate prolactin release in pituitary cells and androgen production in Leydig cells, indicating that it acts as an endocrine disrupter both in cells that secrete by exocytosis of prestored hormones and in cells that secrete by de novo hormone synthesis. Rolipram abolished the stimulatory effect of atrazine on cAMP release in both cell types, suggesting that it acts as an inhibitor of PDE4s, isoforms whose mRNA transcripts dominate in pituitary and Leydig cells together with mRNA for PDE8A. In contrast, immortalized lacto-somatotrophs showed low expression of these mRNA transcripts and several fold higher cAMP levels compared to normal pituitary cells, and atrazine was unable to further increase cAMP levels. These results indicate that atrazine acts as a general endocrine disrupter by inhibiting cAMP-specific PDE4s. PMID:23022511

  7. Interactions between atrazine and phosphorus in aquatic systems: effects on phytoplankton and periphyton.

    PubMed

    Baxter, Leilan R; Sibley, Paul K; Solomon, Keith R; Hanson, Mark L

    2013-01-01

    It has been proposed that the herbicide atrazine may increase rates of parasitic trematode infection in amphibians. This effect may occur indirectly as a result of increased biomass of periphyton and augmented populations of aquatic snails, which are the trematode's primary larval host. Evidence has also shown that nutrients alone may induce the same indirect responses. Since both atrazine and nutrients commonly enter surface waters from agricultural run-off, their spatial and temporal co-occurrence are highly probable. In light of recent wide-spread declines in amphibian populations, a better understanding of the role of atrazine in the proposed ecological mechanism is necessary. A microcosm study was conducted to quantify biomass of phytoplankton and periphyton over a range of atrazine and phosphorus concentrations (from 0 to 200 μg L(-1) each) using a central composite rotatable design. Over 10 weeks, biomass and water chemistry were monitored using standard methods. Regression and canonical analyses of the response surfaces for each parameter were conducted. We found significant effects of atrazine and phosphorus on dissolved oxygen, pH, and conductivity throughout the study. Additions of phosphorus mitigated the apparent inhibition of these photosynthetic indicators caused by atrazine. Despite these changes, no consistent treatment-related differences in algal biomass were observed. These results indicate that the indirect impacts of atrazine on total growth of periphyton and likely, subsequent effects on aquatic snails, are not expected to be ecologically significant at the concentrations of atrazine tested (up to 200 μg L(-1)) and over a range of nutrient conditions commonly occurring in agroecosystems.

  8. Atrazine exposure causes mitochondrial toxicity in liver and muscle cell lines

    PubMed Central

    Sagarkar, Sneha; Gandhi, Deepa; Devi, S. Saravana; Sakharkar, Amul; Kapley, Atya

    2016-01-01

    Objective: Chronic exposure to atrazine and other pesticides is reported to cause metabolic disorders, yet information on effects of atrazine on expression of genes relevant to mitochondrial function is largely missing. In the present study, therefore, we investigated the expression of a battery of nuclear- and mitochondrial-encoded genes involved in oxidative phosphorylation (OXPHOS) in human liver (HepG2) and rat muscle (L6) cell lines due to short-term atrazine exposure. Materials and Methods: We have determined the EC50 values of atrazine for cytotoxicity and mitochondrial toxicity (mitotoxicity) in terms of adenosine triphosphate (ATP) content in HepG2 and L6 cells. Further, the mRNA expression of nuclear- and mitochondrial-encoded genes was analyzed using quantitative real-time polymerase chain reaction. Results: The EC50 value of atrazine for mitotoxicity in HepG2 and L6 cells was found to be about 0.162 and 0.089 mM, respectively. Mitochondrial toxicity was indicated by reduction in ATP content following atrazine exposure. Atrazine exposure resulted in down-regulation of many OXPHOS subunits expression and affected biogenesis factors’ expression. Most prominently, superoxide dismutase (SOD) and sirtuin 3 (SIRT3) expressions were up-regulated in HepG2 cells, whereas SIRT3 expression was alleviated in L6 cells, without significant changes in SOD levels. Mitochondrial transcription factor A (TFAM) and SIRT1 expression were significantly down-regulated in both cell lines. Conclusion: Results suggest that TFAM and SIRT1 could be involved in atrazine-induced mitochondrial dysfunction, and further studies can be taken up to understand the mechanism of mitochondrial toxicity. Further study can also be taken up to explore the possibility of target genes as biomarkers of pesticide toxicity. PMID:27114639

  9. Atrazine and Breast Cancer: A Framework Assessment of the Toxicological and Epidemiological Evidence

    PubMed Central

    Simpkins, James W.; Swenberg, James A.; Weiss, Noel; Brusick, David; Eldridge, J. Charles; Stevens, James T.; Handa, Robert J.; Hovey, Russell C.; Plant, Tony M.; Pastoor, Timothy P.; Breckenridge, Charles B.

    2011-01-01

    The causal relationship between atrazine exposure and the occurrence of breast cancer in women was evaluated using the framework developed by Adami et al. (2011) wherein biological plausibility and epidemiological evidence were combined to conclude that a causal relationship between atrazine exposure and breast cancer is “unlikely”. Carcinogenicity studies in female Sprague-Dawley (SD) but not Fischer-344 rats indicate that high doses of atrazine caused a decreased latency and an increased incidence of combined adenocarcinoma and fibroadenoma mammary tumors. There were no effects of atrazine on any other tumor type in male or female SD or Fischer-344 rats or in three strains of mice. Seven key events that precede tumor expression in female SD rats were identified. Atrazine induces mammary tumors in aging female SD rats by suppressing the luteinizing hormone surge, thereby supporting a state of persistent estrus and prolonged exposure to endogenous estrogen and prolactin. This endocrine mode of action has low biological plausibility for women because women who undergo reproductive senescence have low rather than elevated levels of estrogen and prolactin. Four alternative modes of action (genotoxicity, estrogenicity, upregulation of aromatase gene expression or delayed mammary gland development) were considered and none could account for the tumor response in SD rats. Epidemiological studies provide no support for a causal relationship between atrazine exposure and breast cancer. This conclusion is consistent with International Agency for Research on Cancer’s classification of atrazine as “unclassifiable as to carcinogenicity” and the United States Environmental Protection Agency's classification of atrazine as “not likely to be carcinogenic.” PMID:21768606

  10. Assessing aquifer contamination risk using immunoassay: trace analysis of atrazine in unsaturated zone sediments

    USGS Publications Warehouse

    Juracek, K.E.; Thurman, E.M.

    1997-01-01

    The vulnerability of a shallow aquifer in south-central Kansas to contamination by atrazine (2-chloro-4-ethylamino-6-isopropylamines-triazine) was assessed by analyzing unsaturated zone soil and sediment samples from about 60 dryland and irrigated sites using an ultrasensitive immunoassay (detection level of 0.02 µg/kg) with verification by gas chromatography/mass spectrometry (GC/MS). Samples were collected at depths of 0 to 1.2 m (i.e., the root zone), 1.2 to 1.8 m, and 1.8 to 3.0 m during two time periods-prior to planting and after harvest of crops. About 75% of the samples contained detectable concentrations of parent atrazine. At the shallow sampling depth, atrazine concentrations ranged from 0.5 to approximately 12 µg/kg. Atrazine concentrations at the intermediate (1.2-1.8 m) depth generally were <1.0 µg/kg, with most of the concentrations <0.10 µg/kg, which suggests substantial degradation of parent atrazine in the root zone. Likewise, atrazine concentrations front the deepest (1.8-3.0 m) depth ranged from <0.02 to 0.33 µg/kg. The metabolite deethylatrazine (2-amino-4-chloro-6- isopropylamine-s-triazine) was detected by GC/MS only in 2 of 60 samples with concentrations of 1.4 and 1.5 µg/kg. The reconnaissance survey shows that, in spite of atrazine use ranging from 1 to 5 or more years, there does not appear to he a significant buildup of parent compound below the root zone. Therefore, the unsaturated zone does not appear to be a major storage compartment of atrazine contamination for the underlying shallow aquifer.

  11. Atrazine exposure affects longevity, development time and body size in Drosophila melanogaster.

    PubMed

    Marcus, Sarah R; Fiumera, Anthony C

    2016-01-01

    Atrazine is the one of the most widely used herbicides in the United States and non-target organisms may encounter it in the environment. Atrazine is known to affect male reproduction in both vertebrates and invertebrates but less is known about its effects on other fitness traits. Here we assessed the effects of five different chronic exposure levels on a variety of fitness traits in Drosophila melanogaster. We measured male and female longevity, development time, proportion pupated, proportion emerged, body size, female mating rate, fertility and fecundity. Atrazine exposure decreased the proportion pupated, the proportion emerged and adult survival. Development time was also affected by atrazine and exposed flies pupated and emerged earlier than controls. Although development time was accelerated, body size was actually larger in some of the exposures. Atrazine exposure had no effect on female mating rate and the effects on female fertility and fecundity were only observed in one of the two independent experimental blocks. Many of the traits showed non-monotonic dose response curves, where the intermediate concentrations showed the largest effects. Overall this study shows that atrazine influences a variety of life history traits in the model genetic system, D. melanogaster, and future studies should aim to identify the molecular mechanisms of toxicity. PMID:27317622

  12. Extensive atrazine pollution of drinking water in the Lombardia region and related public health aspects.

    PubMed

    Funari, E; Brambilla, A L; Camoni, I; Canuti, A; Cavallaro, A; Chierici, S; Cialella, G; Donati, G; Jaforte, A; Prandi, L

    1988-12-01

    Introduced in 1957, atrazine is a herbicide used worldwide, mainly in corn cultivation areas for weed control. It is only slightly volatile, is highly soluble in water, and is moderately persistent in topsoil, where it is strongly absorbed to organic carbon. Because of these properties, atrazine can leach to ground water and persist for a long time. This work presents the results obtained so far from an investigation initiated because of an emergency situation in the Lombardia Region of Italy caused by the occurrence of levels of atrazine in drinking water exceeding those established by the European Economic Community and Italian regulations. Water samples from almost 3000 wells were analyzed in different laboratories of the Lombardia Region. Atrazine contamination occurred in a significant number of the wells examined. Examination of the analytical data overall leads to the conclusion that the agricultural use of atrazine in the Lombardia Region is a serious source of ground water contamination. In some areas other factors may be responsible for the contamination of ground water (for instance, industrial activities and/or uncontrolled waste discharges). Geological and hydrological characteristics may play an important role in ground water contamination. Purification systems containing active charcoal seem to be highly efficient in removing atrazine from contaminated water.

  13. Kinetics of aerobic and anaerobic biomineralization of atrazine in surface and subsurface agricultural soils in Ohio.

    PubMed

    Tuovinen, Olli H; Deshmukh, Vaidehi; Özkaya, Bestamin; Radosevich, Mark

    2015-01-01

    The purpose of this study was to assess atrazine mineralization in surface and subsurface samples retrieved from vertical cores of agricultural soils from two farm sites in Ohio. The Defiance site (NW-Ohio) was on soybean-corn rotation and Piketon (S-Ohio) was on continuous corn cultivation. Both sites had a history of atrazine application for at least a couple of decades. The clay fraction increased at the Defiance site and the organic matter and total N content decreased with depth at both sites. Mineralization of atrazine was assessed by measurement of (14)CO2 during incubation of soil samples with [U-ring-(14)C]-atrazine. Abiotic mineralization was negligible in all soil samples. Aerobic mineralization rate constants declined and the corresponding half-lives increased with depth at the Defiance site. Anaerobic mineralization (supplemented with nitrate) was mostly below the detection at the Defiance site. In Piketon samples, the kinetic parameters of aerobic and anaerobic biomineralization of atrazine displayed considerable scatter among replicate cores and duplicate biometers. In general, this study concludes that data especially for anaerobic biomineralization of atrazine can be more variable as compared to aerobic conditions and cannot be extrapolated from one agricultural site to another. PMID:26273756

  14. Effects of atrazine on growth and sex differentiation, in juveniles of the freshwater crayfish Cherax quadricarinatus.

    PubMed

    Mac Loughlin, Camila; Canosa, Ivana S; Silveyra, Gabriela R; López Greco, Laura S; Rodríguez, Enrique M

    2016-09-01

    The effect of the herbicide atrazine was assayed in early juveniles of the redclaw crayfish Cherax quadricarinatus. Four cohorts of juveniles (a total of 280 animals) were exposed for 4 wk to each one of three atrazine concentrations (0.1, 0.5 and 2.5mg/L) or a control (0mg/L), from a commercial formulation having 90% of active principle. At the end of the exposure, no significant (p>0.05) differences in either mortality or molting were noted. However, the weight gain and the protein content of abdominal muscle decreased significantly (p<0.05) in the highest atrazine concentration as compared to control, indicating that atrazine acted as a relevant stressor, although at a concentration higher than those reported in the environment. Besides, the proportion of females increased progressively as the atrazine concentration increases, being significantly (p<0.05) higher than that of controls at the highest concentration assayed. Both macroscopic and histological analysis revealed a normal architecture of gonopores and gonads in both control and exposed animals. The obtained results strongly suggest that atrazine could be causing an endocrine disruption on the hormonal system responsible for the sexual differentiation of the studied species, increasing the proportion of female proportion without disturbing the gonad structure. PMID:27213565

  15. Determining in situ periphyton community responses to nutrient and atrazine gradients via pigment analysis.

    PubMed

    Dalton, Rebecca L; Boutin, Céline; Pick, Frances R

    2015-05-15

    Agrochemicals, including fertilizers and herbicides, are significant contributors of non-point source pollution to surface waters and have the potential to negatively affect periphyton. We characterized periphyton communities using pigment markers to assess the effects of nutrient enrichment and the herbicide atrazine with in situ experimental manipulations and by examining changes in community structure along existing agrochemical gradients. In 2008, the addition of nutrients (20 mg/L nitrate and 1.25 mg/L reactive phosphate), atrazine (20 μg/L) and a combination of both nutrients and atrazine had no significant effect on periphyton biomass or community structure in a stream periphytometer experiment. In 2009, similar experiments with higher concentrations of atrazine (200 μg/L) at two stream sites led to some minor effects. In contrast, at the watershed scale (2010) periphyton biomass (mg/m(2) chlorophyll a) increased significantly along correlated gradients of nitrate and atrazine but no direct effects of reactive phosphate were observed. Across the watershed, the average periphyton community was composed of Bacillariophyceae (60.9%), Chlorophyceae (28.1%), Cryptophyceae (6.9%) and Euglenophyceae (4.1%), with the Bacillariophyceae associated with high turbidity and the Chlorophyceae with nitrate enrichment. Overall, effects of nitrate on periphyton biomass and community structure superseded effects of reactive phosphate and atrazine. PMID:25700361

  16. Inhibition of cytokine production by the herbicide atrazine. Search for nuclear receptor targets.

    PubMed

    Devos, Sabrina; De Bosscher, Karolien; Staels, Bart; Bauer, Ellinor; Roels, Frank; Vanden Berghe, Wim; Haegeman, Guy; Hooghe, Robert; Hooghe-Peters, Elisabeth L

    2003-01-15

    The hematological toxicity of the commonly used triazine herbicides is a cause for concern. In a search for molecular targets of these compounds, as their effects paralleled those seen with dexamethasone (DEX), we first looked for interaction with the glucocorticoid receptor. In contrast to the effects on proliferation and cytokine production of DEX, those induced by atrazine were not prevented by the glucocorticoid antagonist RU486. Also, whereas DEX was able to inhibit the promoter activity of genes regulated by NF-kappaB, atrazine failed to do so. We next looked for interaction with members of the peroxisome proliferator-activated receptor (PPAR) family. No peroxisome proliferation was observed in the liver or kidneys of mice treated with atrazine. Moreover, no PPAR-mediated induction of promoter activity was seen on targets of PPARalpha, PPARgamma, or PPARdelta. Similarly, neither atrazine nor simazine were able to stimulate RORalpha-mediated promoter activity. Finally, no binding of atrazine to the AR was observed. In conclusion, the effects of atrazine-type herbicides most probably do not result from interaction with the above-mentioned nuclear receptors.

  17. Effects of atrazine exposure on male reproductive performance in Drosophila melanogaster

    PubMed Central

    Vogel, Andrea; Jocque, Harper; Sirot, Laura K.; Fiumera, Anthony C.

    2014-01-01

    Atrazine is a commonly utilized herbicide to control broadleaf weeds in the agricultural setting. It can, however, have negative effects on male reproductive performance in a variety of vertebrate species. Much less is known, however, about the effects of atrazine on invertebrates. In this study, we investigated the effects of several different concentrations of larval atrazine exposure on measures of reproductive performance in adult male Drosophila melanogaster. Atrazine exposure had significant effects on a male’s mating ability and the number of eggs his partner lays when he was successful at mating. Exposed males also sired a smaller proportion of the offspring under competitive conditions when they were the first male to mate to a doubly mated female. Atrazine exposure had no measurable effect on a male’s ability to prevent a mated female from mating to another male or on the proportion of offspring sired when the exposed males were the second male to mate. Exposure upregulated expression of one male reproductive gene, ovulin, but had no effect on expression of another, sex peptide. Exposed males produced and transferred more sex peptide protein to the female during mating but ovulin protein levels were not affected. In general, we observed non-monotonic responses such that the intermediate exposure levels showed the largest reduction in male reproductive performance. This study suggests that atrazine exposure affects male reproductive performance in insects and future studies should aim to understand the molecular mechanisms underlying the fitness effects of exposure. PMID:25445663

  18. Groundwater as a nonpoint source of atrazine and deethylatrazine in a river during base flow conditions

    USGS Publications Warehouse

    Squillace, Paul J.; Thurman, E.M.; Furlong, Edward T.

    1993-01-01

    Alluvial groundwater adjacent to the main stem river is the principal nonpoint source of atrazine and deethylatrazine in the Cedar River of Iowa after the river has been in base flow conditions for 5 days. Between two sites along a 116-km reach of the Cedar River, tributaries contributed about 25% of the increase in the atrazine and deethylatrazine load, whereas groundwater from the alluvial aquifer contributed at least 75% of the increase in load. Within the study area, tributaries aggregate almost all of the discharge from tile drains, and yet the tributaries still only contribute 25% of the increase in loads in the main stem river. At an unfamned study site adjacent to the Cedar River, the sources of atrazine and deethylatrazine in the alluvial groundwater are bank storage of river water and groundwater recharge from areas distant from the river. Atrazine and deethylatrazine associated with bank storage water will provide larger concentrations to the river during early base flow conditions. After the depletion of bank storage, stable and smaller concentrations of atrazine and deethylatrazine, originating from groundwater recharge, continue to be discharged from the alluvial aquifer to the river; thus these results indicate that alluvial aquifers are an important nonpoint source of atrazine and deethylatrazine in rivers during base flow.

  19. Prenatal exposure to low doses of atrazine affects mating behaviors in male guppies.

    PubMed

    Shenoy, Kausalya

    2014-07-01

    Performing appropriate mating behaviors is crucial to male reproductive success, especially in species where mating is predominantly via female mate choice. Mating behaviors are hormonally regulated and may be sexually selected traits: courtship displays are selected via mate choice, while forced copulations and aggressive behaviors are selected for via intrasexual competition. Endocrine disrupting compounds interfere with proper hormonal functioning in exposed animals. Exposures during developmentally crucial life stages can have irreversible effects lasting through adulthood. I tested the effects of prenatal exposure to environmentally relevant doses of a commonly used herbicide, atrazine (1 and 13.5μg/L) on mating behaviors in male guppies. Guppies were used as a model organism to test the effects of atrazine exposure on wildlife reproductive health. Adult female guppies were mated and exposed to the treatments throughout the gestation period, and offspring born to them were raised without further treatment. At adulthood, the males were tested for the effects of prenatal exposure on their mating behaviors such as courtship displays, gonopodium swings, forced copulatory attempts, and competitive and aggressive behaviors towards rivals who were not exposed to atrazine. I also tested female preference for treated males compared to control males. Atrazine-exposed males were less likely to perform the mating behaviors, and performed them less frequently, than control males. Atrazine exposure also made males less aggressive towards rivals. Females preferred untreated males over atrazine-treated males. In all cases, a non-monotonic pattern was seen, highlighting the significance of low-dose exposures.

  20. Effects of atrazine exposure on male reproductive performance in Drosophila melanogaster.

    PubMed

    Vogel, Andrea; Jocque, Harper; Sirot, Laura K; Fiumera, Anthony C

    2015-01-01

    Atrazine is a commonly utilized herbicide to control broadleaf weeds in the agricultural setting. It can, however, have negative effects on male reproductive performance in a variety of vertebrate species. Much less is known, however, about the effects of atrazine on invertebrates. In this study, we investigated the effects of several different concentrations of larval atrazine exposure on measures of reproductive performance in adult male Drosophila melanogaster. Atrazine exposure had significant effects on a male's mating ability and the number of eggs his partner laid when he was successful at mating. Exposed males also sired a smaller proportion of the offspring under competitive conditions when they were the first male to mate to a doubly mated female. Atrazine exposure had no measurable effect on a male's ability to prevent a mated female from mating to another male or on the proportion of offspring sired when the exposed males were the second male to mate. Exposure upregulated expression of one male reproductive gene, ovulin, but had no effect on expression of another, sex peptide. Exposed males produced and transferred more sex peptide protein to the female during mating but ovulin protein levels were not affected. In general, we observed non-monotonic responses such that the intermediate exposure levels showed the largest reduction in male reproductive performance. This study suggests that atrazine exposure affects male reproductive performance in insects and future studies should aim to understand the molecular mechanisms underlying the fitness effects of exposure.

  1. Degradation of atrazine in two soils as a function of concentration

    SciTech Connect

    Gan, J.; Becker, R.L.; Buhler, D.D.; Koskinen, W.C.

    1996-09-01

    Dissipation of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) in a Webster clay loam soil (fine loamy, mixed, mesic Typic Haplaquoll), and Estherville sandy loam (sandy, mixed, mesic typic Hapludoll) was determined over a concentration range of 5 to 5000 mg kg{sup -1} in field and laboratory experiments. Over the first 6 mo in the clay loam soil, the persistance of atrazine (based on percent of applied) was greater for the high-rate treatments than the low-rate treatments. However, in the laboratory, there was no effect of concentration on dissipation; the amount of atrazine degraded increased proportionally with the increase of concentration. In the sandy loam, persistance was greater at high concentration in both field and laboratory studies. Mineralization was the most important pathway for the dissipation of atrazine at all concentrations in the clay loam soil and from 5 to 500 mg kg{sup -1} may have increased soil microbial growth and activity and thus increased the degradation of atrazine based on the increase in soil respiration in the clay loam soil. Degradation pathways in both soils apparently were not influenced by concentration. Ring cleavage and hydrolysis were the major metabolic pathways in both soils, with dealkylation of less importance. Addition of a dairy manure amendment increased the rate of atrazine mineralization, while corn mean decreased and (NH{sub 4}){sub 2}HPO{sub 4} amendments prevented mineralization. 41 refs., 6 figs., 4 tabs.

  2. Ageing of atrazine in manure amended soils assessed by bioavailability to Pseudomonas sp. strain ADP.

    PubMed

    Glæsner, Nadia; Bælum, Jacob; Strobel, Bjarne W; Jacobsen, Carsten S

    2014-04-01

    Animal manure is applied to agricultural land in areas of high livestock production. In the present study, we evaluated ageing of atrazine in two topsoils with and without addition of manure and in one subsoil. Ageing was assessed as the bioavailability of atrazine to the atrazine mineralizing bacteria Pseudomonas sp. strain ADP. Throughout an ageing period of 90 days bioavailability was investigated at days 1, 10, 32, 60 and 90, where ~10(8) cells g(-1) of the ADP strain was inoculated to the (14)C-atrazine exposed soil and (14)CO2 was collected over 7 days as a measure of mineralized atrazine. Even though the bioavailable residue decreased in all of the three soils as time proceeded, we found that ageing occurred faster in the topsoils rich in organic carbon than in subsoil. For one topsoil rich in organic carbon content, Simmelkær, we observed a higher degree of ageing when treated with manure. Contrarily, sorption experiments showed less sorption to Simmelkær treated with manure than the untreated soil indicating that sorption processes are not the only mechanisms of ageing. The other topsoil low in organic carbon content, Ringe, showed no significant difference in ageing between the manure-treated and untreated soil. The present study illustrates that not simply the organic carbon content influences adsorption and ageing of atrazine in soil but the origin and composition of organic matter plays an important role.

  3. Kinetics of aerobic and anaerobic biomineralization of atrazine in surface and subsurface agricultural soils in Ohio.

    PubMed

    Tuovinen, Olli H; Deshmukh, Vaidehi; Özkaya, Bestamin; Radosevich, Mark

    2015-01-01

    The purpose of this study was to assess atrazine mineralization in surface and subsurface samples retrieved from vertical cores of agricultural soils from two farm sites in Ohio. The Defiance site (NW-Ohio) was on soybean-corn rotation and Piketon (S-Ohio) was on continuous corn cultivation. Both sites had a history of atrazine application for at least a couple of decades. The clay fraction increased at the Defiance site and the organic matter and total N content decreased with depth at both sites. Mineralization of atrazine was assessed by measurement of (14)CO2 during incubation of soil samples with [U-ring-(14)C]-atrazine. Abiotic mineralization was negligible in all soil samples. Aerobic mineralization rate constants declined and the corresponding half-lives increased with depth at the Defiance site. Anaerobic mineralization (supplemented with nitrate) was mostly below the detection at the Defiance site. In Piketon samples, the kinetic parameters of aerobic and anaerobic biomineralization of atrazine displayed considerable scatter among replicate cores and duplicate biometers. In general, this study concludes that data especially for anaerobic biomineralization of atrazine can be more variable as compared to aerobic conditions and cannot be extrapolated from one agricultural site to another.

  4. Determining in situ periphyton community responses to nutrient and atrazine gradients via pigment analysis.

    PubMed

    Dalton, Rebecca L; Boutin, Céline; Pick, Frances R

    2015-05-15

    Agrochemicals, including fertilizers and herbicides, are significant contributors of non-point source pollution to surface waters and have the potential to negatively affect periphyton. We characterized periphyton communities using pigment markers to assess the effects of nutrient enrichment and the herbicide atrazine with in situ experimental manipulations and by examining changes in community structure along existing agrochemical gradients. In 2008, the addition of nutrients (20 mg/L nitrate and 1.25 mg/L reactive phosphate), atrazine (20 μg/L) and a combination of both nutrients and atrazine had no significant effect on periphyton biomass or community structure in a stream periphytometer experiment. In 2009, similar experiments with higher concentrations of atrazine (200 μg/L) at two stream sites led to some minor effects. In contrast, at the watershed scale (2010) periphyton biomass (mg/m(2) chlorophyll a) increased significantly along correlated gradients of nitrate and atrazine but no direct effects of reactive phosphate were observed. Across the watershed, the average periphyton community was composed of Bacillariophyceae (60.9%), Chlorophyceae (28.1%), Cryptophyceae (6.9%) and Euglenophyceae (4.1%), with the Bacillariophyceae associated with high turbidity and the Chlorophyceae with nitrate enrichment. Overall, effects of nitrate on periphyton biomass and community structure superseded effects of reactive phosphate and atrazine.

  5. Effects of atrazine on metamorphosis, growth, and gonadal development in the green frog (Rana clamitans).

    PubMed

    Coady, Katherine; Murphy, Margaret; Villeneuve, Daniel; Hecker, Markus; Jones, Paul; Carr, James; Solomon, Keith; Smith, Ernest; Van Der Kraak, Glen; Kendall, Ronald; Giesy, John

    2004-06-25

    Embryos of the green frog (Rana clamitans) were collected from the field and exposed to 1 of 6 water-borne treatments for 273 d (mid July 2001 to mid April 2002). The treatments were 0, 10, or 25 microg/L atrazine, 0.005% ethanol (EtOH), or 0.1 mg/L estradiol or dihydrotestosterone carried in 0.005% EtOH. Treatments were applied in a static renewal system with a 50% test solution replacement approximately every 3 d. Following the exposure period, tadpoles were reared in freshwater until metamorphosis or until study termination (at d 506). Time to initiate and complete metamorphosis, stage-specific mortality, length and weight at metamorphosis, and gross morphology and histology of the gonads were examined. At environmentally relevant concentrations, atrazine did not consistently affect growth or metamorphosis. Compared to controls, the length of the larval period was greater in tadpoles exposed to 10 microg/L atrazine. However, the length of the larval period was not markedly different between tadpoles in the control and 25 microg/L atrazine treatments. Neither gross gonadal morphology nor histopathology of the gonads in postmetamorphic frogs was significantly altered in response to atrazine exposure. This study provides evidence that environmentally relevant concentrations of atrazine do not adversely affect the growth or reproductive development of R. clamitans.

  6. Maternal Residential Atrazine Exposure and Risk for Choanal Atresia and Stenosis in Offspring

    PubMed Central

    Agopian, A.J.; Cai, Yi; Langlois, Peter H.; Canfield, Mark A.; Lupo, Philip J.

    2014-01-01

    Objective To assess the relationship between estimated residential maternal exposure to atrazine during pregnancy and risk for choanal atresia or stenosis in offspring. Study Design Data for 280 nonsyndromic cases and randomly selected, population-based controls delivered during 1999 to 2008 were obtained from the Texas Birth Defects Registry. County-level estimates of atrazine levels obtained from the United States Geological Survey were assigned to cases and controls based on maternal county of residence at delivery. Unconditional logistic regression was used to assess the relationship between maternal residential atrazine exposure and risk for choanal atresia or stenosis in offspring. Results Compared to offspring of mothers with low levels of estimated residential atrazine exposure, those with high levels had nearly a two-fold increase in risk for choanal atresia or stenosis (adjusted odds ratio: 1.79, 95% confidence interval: 1.17–2.74). A significant linear trend was also observed with increasing levels of atrazine exposure (adjusted P = 0.002). Conclusions A link between maternal exposure to endocrine disruptors, such as atrazine, and choanal atresia risk is plausible based on previous findings. Our results further support this hypothesis. PMID:23036484

  7. Atrazine and increased male production by Daphnia: the importance of combining field and laboratory approaches.

    PubMed

    Stoeckel, James A; González, María J; Oris, James T; Kovach, Mathew J; Mace, Kimberly M

    2008-11-01

    Atrazine is one of the most commonly applied herbicides in North America and annually pulses through many midwestern stream and reservoir systems. Previous studies have yielded conflicting results regarding the ability of atrazine to stimulate male production by Daphnia, an effect hypothesized to lower population growth rates during a period of intense larval fish predation. In the present study, populations of Daphnia parvula and Daphnia ambigua exhibited high proportions of males but no ephippial females when atrazine pulsed into Acton Lake, a small midwestern reservoir. Field results thus supported the hypothesis of excess male production by Daphnia during the spring herbicide pulse. In laboratory studies, dose-response studies, and population-level assays revealed no effect of atrazine on male production or population growth rate of multiple clones differing in reproductive strategy and exposure history. However, D. parvula increased male production in response to an endogenous crustacean hormone (methyl farnesoate). Excess male production observed in the field population was therefore not likely caused by atrazine, although we cannot rule out the possibility of interactive effects of atrazine and some other stressor. Apparent signs of endocrine disruption in the presence of high concentrations of a suspected agent should be viewed with caution in the absence of parallel laboratory studies involving individuals from the populations of interest.

  8. Cytotoxic effects and apoptosis induction of atrazine in a grass carp (Ctenopharyngodon idellus) cell line.

    PubMed

    Liu, Xin-Mei; Shao, Jian-Zhong; Xiang, Li-Xin; Chen, Xiao-Yong

    2006-02-01

    Atrazine is a widely used herbicide that was considered to be an endocrine disrupter capable of interfering with the synthesis and action of natural hormones. In the present study, we found that atrazine was able to cause apoptosis in grass carp (Ctenopharyngodon idellus) cells from cell line ZC7901. By fluorescent and transmission electron microscopy, the atrazine-incubated cells displayed a series of morphological changes, including condensation of the nucleus, margination of chromatin to form dense granular caps, and formation of apoptotic bodies. Moreover, DNA fragmentation was detected by the TUNEL reaction and agarose gel electrophoresis. These typical characteristics of cells undergoing apoptosis indicated the occurrence of apoptosis in ZC7901. Apoptosis induced by atrazine was dose- and time-dependent and was involved in mitochondrial membrane potential (DeltaPsi(m)) disruption, elevation in intracellular Ca(2+), generation of reactive oxygen species, and intracellular ATP depletion. This study provides the first evidence that atrazine was able to induce apoptosis in fish cells, which indicated the existence of a novel cytotoxic mechanism caused by atrazine and may improve our understanding of the complex relationship between contaminants and aquatic organisms.

  9. Effects of atrazine on anuran development are altered by the presence of a nonlethal predator.

    PubMed

    LaFiandra, Emily May; Babbitt, Kimberly J; Sower, Stacia A

    2008-01-01

    Although predator-induced stress is a common biotic factor in aquatic communities that can strongly influence anuran development, there have been no studies to date that examined the interaction between this factor and atrazine, the most widely used pesticide in the United States. The potential synergistic effects of atrazine (0, 20, or 200 microg/L) and predatory stress on the survival, growth, development, and reproductive development of Hyla versicolor (gray treefrog) tadpoles were investigated. Atrazine reduced the proportion of tadpoles reaching metamorphosis; however, this effect was modified by the presence of a nonlethal predator. The combined effects of predatory stress and exposure to 200 microg/L atrazine resulted in the lowest proportion of tadpoles reaching metamorphosis. No treatment effects were observed for mass, snout-urostyle length, or the proportion of metamorphs that were male or female. No macroscopic gonadal anomalies were observed. Many gonads were underdeveloped; however, gonadal development was more advanced in metamorphs exposed to 200 microg/L atrazine. This effect was modified by the presence of a nonlethal predator such that female gonadal development was further accelerated and male gonadal development was retarded by predatory stress. These results indicate that simplified laboratory studies may not accurately reflect the effects of atrazine on anuran development in natural communities.

  10. Effects of environmentally relevant concentrations of atrazine on gonadal development of snapping turtles (Chelydra serpentina).

    PubMed

    de Solla, Shane R; Martin, Pamela A; Fernie, Kimberly J; Park, Brad J; Mayne, Gregory

    2006-02-01

    The herbicide atrazine has been suspected of affecting sexual development by inducing aromatase, resulting in the increased conversion of androgens to estrogens. We used snapping turtles (Chelydra serpentina), a species in which sex is dependent on the production of estrogen through aromatase activity in a temperature-dependent manner, to investigate if environmentally relevant exposures to atrazine affected gonadal development. Eggs were incubated in soil to which atrazine was applied at a typical field application rate (3.1 L/ha), 10-fold this rate (31 L/ha), and a control rate (no atrazine) for the duration of embryonic development. The incubation temperature (25 degrees C) was selected to produce only males. Although some males with testicular oocytes and females were produced in the atrazine-treated groups (3.3-3.7%) but not in the control group, no statistical differences were found among treatments. Furthermore, snapping turtle eggs collected from natural nests in a corn field were incubated at the pivotal temperature (27.5 degrees C) at which both males and females normally would be produced, and some males had oocytes in the testes (15.4%). The presence of low numbers of males with oocytes may be a natural phenomenon, and we have limited evidence to suggest that the presence of normal males with oocytes may represent a feminizing effect of atrazine. Histological examination of the thyroid gland revealed no effect on thyroid morphology. PMID:16519315

  11. Effects of atrazine on growth and sex differentiation, in juveniles of the freshwater crayfish Cherax quadricarinatus.

    PubMed

    Mac Loughlin, Camila; Canosa, Ivana S; Silveyra, Gabriela R; López Greco, Laura S; Rodríguez, Enrique M

    2016-09-01

    The effect of the herbicide atrazine was assayed in early juveniles of the redclaw crayfish Cherax quadricarinatus. Four cohorts of juveniles (a total of 280 animals) were exposed for 4 wk to each one of three atrazine concentrations (0.1, 0.5 and 2.5mg/L) or a control (0mg/L), from a commercial formulation having 90% of active principle. At the end of the exposure, no significant (p>0.05) differences in either mortality or molting were noted. However, the weight gain and the protein content of abdominal muscle decreased significantly (p<0.05) in the highest atrazine concentration as compared to control, indicating that atrazine acted as a relevant stressor, although at a concentration higher than those reported in the environment. Besides, the proportion of females increased progressively as the atrazine concentration increases, being significantly (p<0.05) higher than that of controls at the highest concentration assayed. Both macroscopic and histological analysis revealed a normal architecture of gonopores and gonads in both control and exposed animals. The obtained results strongly suggest that atrazine could be causing an endocrine disruption on the hormonal system responsible for the sexual differentiation of the studied species, increasing the proportion of female proportion without disturbing the gonad structure.

  12. Response of phytoplankton community to low-dose atrazine exposure combined with phosphorus fluctuations.

    PubMed

    Pannard, Alexandrine; Le Rouzic, Bertrand; Binet, Françoise

    2009-07-01

    The effects of atrazine on a controlled phytoplankton community derived from a natural freshwater wetland exposed to low doses of this photosynthesis-inhibiting herbicide were examined. The community was exposed for 7 weeks to doses of 0.1, 1, and 10 microg L(-1) atrazine, combined with changes in nutrient concentration, and the photosynthetic activity, biomass, and community structure were noted during the experiment. Responses of the phytoplankton community were examined in terms of photosynthetic activity, biomass, and community structure. Significant effects of atrazine on the phytoplankton assemblage, in terms of primary production and community structure, were highlighted, even at doses as low as 1 and 0.1 microg L(-1), when associated with phosphorus fluctuations. The most abundant Chlorophyceae decreased in concentration with increasing atrazine dose, whereas cyanobacteria were more tolerant to atrazine, particularly with increased nutrient supply. The subinhibitory doses of atrazine used in the present study confirmed the higher sensitivity of long-term exposure of multispecies assemblages under resource competition. Our study supports the emerging hypothesis that the increasing prevalence of cyanobacterial blooms in European aquatic systems may result from a combination of unbalanced nutrient enrichment and selective pressures from multiple toxicants.

  13. Gamma-ray induced degradation of diazinon and atrazine in natural groundwaters.

    PubMed

    Mohamed, K A; Basfar, A A; Al-Shahrani, A A

    2009-07-30

    Degradation of diazinon and atrazine pesticides present in natural groundwaters was investigated on a laboratory scale upon gamma-irradiation from a (60)Co source. The effects of pesticide type, initial concentration, characteristics of natural groundwater, potential radical scavengers and absorbed dose on efficiency of pesticide degradation were investigated using GC-MS. gamma-Irradiation experiments were carried out for three concentrations (i.e. 0.329, 1.643 and 3.286 microM/diazinon and 0.464, 2.318 and 4.636 microM/atrazine) with irradiation doses over the range 0.5-5.6 kGy for diazinon and 0.2-21 kGy for atrazine. gamma-Radiolysis showed that diazinon was much easier to degrade by ionizing radiation compared to atrazine in all natural groundwater samples. This was observed at the three initial concentrations over the range irradiation doses. The irradiation doses required for degradation of 50 and 90% diazinon (distilled water) and atrazine (humic aqueous solution) at the three concentrations were not sufficient to degrade the same concentrations in different natural groundwater samples. Moreover, the presence of naturally occurring inorganic scavengers in solutions of diazinon and atrazine decreased significantly the efficiency of radiolytic degradation of pesticides, especially at higher concentrations.

  14. Movement of atrazine and deethylatrazine through a midwestern reservoir

    USGS Publications Warehouse

    Fallon, J.D.; Tierney, D.P.; Thurman, E.M.

    2002-01-01

    The three-dimensional visualization of atrazine and deethylatrazine in a reservoir was determined by five "snapshots" over a one-year period using immunoassay analyses, confirmed by gas chromatography-mass spectrometry and visualized with a three-dimensional computer program. The surveys were conducted in Perry Lake in Kansas and showed that spring runoff laden with triazine herbicides entered the reservoir and did not mix immediately. Concentrations varied threefold between the inlet and the public water supply intakes located at the opposite end of the reservoir. The concentration range in the outflow varied much less than the concentration in the reservoir because of mixing throughout the season near the dam and outflow. A major conclusion from the study was that multiple analyses by a low-cost immunoassay technique coupled with computer visualization software gave a good three-dimensional view of the mass of herbicide present in a drinking water reservoir.

  15. Alterations in juvenile diploid and triploid African catfish skin gelatin yield and amino acid composition: Effects of chlorpyrifos and butachlor exposures.

    PubMed

    Karami, Ali; Karbalaei, Samaneh; Zad Bagher, Fariba; Ismail, Amin; Simpson, Stuart L; Courtenay, Simon C

    2016-08-01

    Skin is a major by-product of the fisheries and aquaculture industries and is a valuable source of gelatin. This study examined the effect of triploidization on gelatin yield and proximate composition of the skin of African catfish (Clarias gariepinus). We further investigated the effects of two commonly used pesticides, chlorpyrifos (CPF) and butachlor (BUC), on the skin gelatin yield and amino acid composition in juvenile full-sibling diploid and triploid African catfish. In two separate experiments, diploid and triploid C. gariepinus were exposed for 21 days to graded CPF [mean measured: 10, 16, or 31 μg/L] or BUC concentrations [Mean measured: 22, 44, or 60 μg/L]. No differences in skin gelatin yield, amino acid or proximate compositions were observed between diploid and triploid control groups. None of the pesticide treatments affected the measured parameters in diploid fish. In triploids, however, gelatin yield was affected by CPF treatments while amino acid composition remained unchanged. Butachlor treatments did not alter any of the measured variables in triploid fish. To our knowledge, this study is the first to investigate changes in the skin gelatin yield and amino acid composition in any animal as a response to polyploidization and/or contaminant exposure.

  16. Persistence of 14C-labeled atrazine and its residues in a field lysimeter soil after 22 years.

    PubMed

    Jablonowski, Nicolai D; Köppchen, Stephan; Hofmann, Diana; Schäffer, Andreas; Burauel, Peter

    2009-07-01

    Twenty-two years after the last application of ring-14C-labeled atrazine at customary rate (1.7 kg ha(-1)) on an agriculturally used outdoor lysimeter, atrazine is still detectable by means of accelerated solvent extraction and LC-MS/MS analysis. Extractions of the 0-10 cm soil layer yielded 60% of the residual 14C-activity. The extracts contained atrazine (1.0 microg kg(-1)) and 2-hydroxy-atrazine (42.5 microg kg(-1)). Extractions of the material of the lowest layer 55-60 cm consisting of fine gravel yielded 93% of residual 14C-activity, of which 3.4 microg kg(-1) was detected as atrazine and 17.7 microg kg(-1) was 2-hydroxy-atrazine. The detection of atrazine in the lowest layer was of almost four times higher mass than in the upper soil layer. These findings highlight the fact that atrazine is unexpectedly persistent in soil. The overall persistence of atrazine in the environment might represent a potential risk for successive groundwater contamination by leaching even after 22 years of environmental exposure.

  17. Atrazine Triggers DNA Damage Response and Induces DNA Double-Strand Breaks in MCF-10A Cells.

    PubMed

    Huang, Peixin; Yang, John; Ning, Jie; Wang, Michael; Song, Qisheng

    2015-06-24

    Atrazine, a pre-emergent herbicide in the chloro-s-triazine family, has been widely used in crop lands and often detected in agriculture watersheds, which is considered as a potential threat to human health. Although atrazine and its metabolites showed an elevated incidence of mammary tumors in female Sprague-Dawley (SD) rats, no molecular evidence was found relevant to its carcinogenesis in humans. This study aims to determine whether atrazine could induce the expression of DNA damage response-related proteins in normal human breast epithelial cells (MCF-10A) and to examine the cytotoxicity of atrazine at a molecular level. Our results indicate that a short-term exposure of MCF-10A to an environmentally-detectable concentration of atrazine (0.1 µg/mL) significantly increased the expression of tumor necrosis factor receptor-1 (TNFR1) and phosphorylated Rad17 in the cells. Atrazine treatment increased H2AX phosphorylation (γH2AX) and the formation of γH2AX foci in the nuclei of MCF-10A cells. Atrazine also sequentially elevated DNA damage checkpoint proteins of ATM- and RAD3-related (ATR), ATRIP and phospho-Chk1, suggesting that atrazine could induce DNA double-strand breaks and trigger the DNA damage response ATR-Chk1 pathway in MCF-10A cells. Further investigations are needed to determine whether atrazine-triggered DNA double-strand breaks and DNA damage response ATR-Chk1 pathway occur in vivo.

  18. Degradation of atrazine and 2, 4-dichlorophenoxyacetic acid by mycorrhizal fungi at three nitrogen concentrations in vitro

    SciTech Connect

    Donnelly, P.K.; Crawford, D.L. ); Entry, J.A. )

    1993-08-01

    Atrazine is a chlorinated aromatic hydrocarbon with an extremely low rated of degradation, especially in cold, dry climates. Biodegradation of the herbicide 2,4-D is known to occur in warm, moist soil, but it is dependent on environmental conditions and soil characteristics. This study examines the biodegradation of Atrazine and 2,4-D under various physiological conditions. Both mycorrhizal and nonmycorrhizal fungi were used. Phanerochaete chrysosporium was the best 2,4-D-degrading organism, but it was not able to mineralize atrazine. The ericoid mycorrhizal fungi degraded atrazine most effectively. 28 refs., 4 tabs.

  19. Antioxidant Attenuation of Atrazine Induced Histopathological Changes in Testicular Tissue of Goat In Vitro

    PubMed Central

    Sharma, R. K.; Fulia, Anju; Chauhan, P. K.

    2012-01-01

    During the present investigation the effect of α-tocopherol (100 μmolL-1) in prevention of testicular toxicity induced by atrazine in goat Capra hircus have been analyzed. Vitamin E (α-tocopherol) at dose level 100 μmolL-1 provides attenuation over the histopathological changes generated by pesticide atrazine (100 nmolml-1). Small pieces (approximately 1mm3) of testicular tissue were divided into three groups (one control group + two experimental groups). Experimental group (A) was supplemented with 100 nmolml-1 concentration of atrazine and experimental group (B) was supplemented with 100 nmolml-1 atrazine and 100 μmolL-1 concentrations of vitamin E (α-Tocopherol) and harvesting was carried out after 1, 4 and 8 hrs of exposure. Control was run along with all the experimental groups. In the experimental group (A) treated with atrazine at dose level 100 nmolml-1, revealed histomorphological alterations in the seminiferous tubule. After one hour of exposure duration small vacuoles in cytoplasm of the Sertoli cells and spermatogonia were observed. Chromolysis at pycnosis were also noticed in the spermatogonia and spermatids. In the experimental group (B) exposed with atrazine and simultaneously supplemented with Vitamin E also showed degeneration but it was milder as compared with experimental group treated with atrazine without antioxidant. Atrazine exposure induced a decline in diameter of spermatocytes from 10.51 ± 0.2052 μm in control to 7.915 ± 0.2972, 7.5 ± 0.211 and 7.14 ± 0.225 μm after exposure of 1, 4 and 8 hrs respectively but in case of atrazine supplemented with vitamin E [experimental group (B)], there was less decline in cell diameter that was 8.5 ± 0.1865, 8.1 ± 0.1201 and 7.8 ± 0.2066μm after exposure of 1, 4 and 8 hrs respectively. The result demonstrated that vitamin E delays the degenerative changes induced by atrazine. PMID:23293464

  20. Response to variable light intensity in photoacclimated algae and cyanobacteria exposed to atrazine.

    PubMed

    Deblois, Charles P; Dufresne, Karine; Juneau, Philippe

    2013-01-15

    Atrazine is frequently detected in freshwater ecosystems exposed to agricultural waste waters and runoffs worldwide and it can affect non-target organisms (mainly photoautotrophic) and modify community structure. Meanwhile, light environment is known to vary between aquatic ecosystems, but also before and during the exposure to atrazine and these variations may modify the sensitivity to atrazine of photoautotroph organisms. In this study, 10 species of phytoplankton (chlorophytes, baccilariophytes and cyanophytes) acclimated to low or high light intensities were exposed to atrazine and light of different intensities to compare their combined effect. Our data showed that chlorophytes and baccilariophytes were more resistant to atrazine compared to cyanophytes for all light conditions. Atrazine was found to inhibit Φ'(M), Ψ(0), P(M) and non-photochemical quenching for all species indicating an effect on electron transport, primary production and photoregulation processes. These data also indicate a higher sensitivity of Ψ(0) (average Ψ(0)-EC(50) of 91 ± 11 nM or 19.6 ± 0.9 μgL(-1)) compared to Φ'(M) (average Φ'(M)-EC(50) of 217 ± 19 nM or 46.8 ± 4.1 μgL(-1)) and suggest that photoregulation processes activated in presence of light decrease the effect of atrazine. We also showed that increasing light intensity decreased Φ'(M)-EC(50) in both low (except baccilariophytes) and high light acclimated conditions. Despite this similarity, most species acclimated to high light were found to have higher or similar Φ'(M)-EC(50) compared to low light acclimated cells and thus, were less sensitive to atrazine in low light and high light environments. We concluded that an increase in the plastoquinone pool induced by acclimation to high light decreased the sensitivity to atrazine in phytoplankton and we hypothesized that the effect observed was the result of a dilution of atrazine toxicity through increased binding site availability (quinones) combined with increased

  1. Effects of Prenatal Exposure to a Low Dose Atrazine Metabolite Mixture on pubertal timing and prostrate Development of Male Long Evans Rats.

    EPA Science Inventory

    The present study examines the postnatal reproductive development of male rats following prenatal exposure to an atrazine metabolite mixture (AMM) consisting of the herbicide atrazine and its environmental metabolites diaminochlorotriazine, hydroxyatrazine, deethylatrazine, and d...

  2. Vulnerability of ground water to atrazine leaching in Kent County, Michigan

    USGS Publications Warehouse

    Holtschlag, D.J.; Luukkonen, C.L.

    1997-01-01

    A steady-state model of pesticide leaching through the unsaturated zone was used with readily available hydrologic, lithologic, and pesticide characteristics to estimate the vulnerability of the near-surface aquifer to atrazine contamination from non-point sources in Kent County, Michigan. The modelcomputed fraction of atrazine remaining at the water table, RM, was used as the vulnerability criterion; time of travel to the water table also was computed. Model results indicate that the average fraction of atrazine remaining at the water table was 0.039 percent; the fraction ranged from 0 to 3.6 percent. Time of travel of atrazine from the soil surface to the water table averaged 17.7 years and ranged from 2.2 to 118 years.Three maps were generated to present three views of the same atrazine vulnerability characteristics using different metrics (nonlinear transformations of the computed fractions remaining). The metrics were chosen because of the highly (right) skewed distribution of computed fractions. The first metric, rm = RMλ (where λ was 0.0625), depicts a relatively uniform distribution of vulnerability across the county with localized areas of high and low vulnerability visible. The second metric, rmλ-0.5, depicts about one-half the county at low vulnerability with discontinuous patterns of high vulnerability evident. In the third metric, rmλ-1.0 (RM), more than 95 percent of the county appears to have low vulnerability; small, distinct areas of high vulnerability are present.Aquifer vulnerability estimates in the RM metric were used with a steady-state, uniform atrazine application rate to compute a potential concentration of atrazine in leachate reaching the water table. The average estimated potential atrazine concentration in leachate at the water table was 0.16 μg/L (micrograms per liter) in the model area; estimated potential concentrations ranged from 0 to 26 μg/L. About 2 percent of the model area had estimated potential atrazine concentrations

  3. Fate of atrazine in a soil under different agronomic management practices.

    PubMed

    Prado, B; Fuentes, M; Verhulst, N; Govaerts, B; De León, F; Zamora, O

    2014-01-01

    Agricultural management affects the movement of atrazine in soil and leaching to groundwater. The objective of this study was to determine atrazine adsorption in a soil after 20 years of atrazine application under agronomic management practices differing in tillage practice (conventional and zero tillage), residue management (with and without residue retention) and crop rotation (wheat-maize rotation and maize monoculture). Atrazine sorption was determined using batch and column experiments. In the batch experiment, the highest distribution coefficient Kd (1.1 L kg(-1)) at 0-10 cm soil depth was observed under zero tillage, crop rotation and residue retention (conservation agriculture). The key factor in adsorption was soil organic matter content and type. This was confirmed in the column experiment, in which the highest Kd values were observed in treatments with residue retention, under either zero or conventional tillage (0.81 and 0.68 L kg(-1), respectively). Under zero tillage, the fact that there was no soil movement helped to increase the Kd. The increased soil organic matter content with conservation agriculture may be more important than preferential flow due to higher pore connectivity in the same system. The soil's capacity to adsorb 2-hydroxyatrazine (HA), an important atrazine metabolite, was more important than its capacity to adsorb atrazine, and was similar under all four management practices (Kd ranged from 30 to 40 L kg(-1)). The HA adsorption was attributed to the type and amount of clay in the soil, which is unaffected by agronomic management. Soils under conservation agriculture had higher atrazine retention potential than soils under conventional tillage, the system that predominates in the study area. PMID:25190559

  4. Variability in carbon and nitrogen isotope fractionation associated with bacterial hydrolysis of atrazine

    NASA Astrophysics Data System (ADS)

    Meyer, A.; Penning, H.; Elsner, M.

    2009-04-01

    Even after legislative prohibition in 1991 by the European Union, the pesticide atrazine and its metabolites are still detected in surface and ground water frequently exceeding the permitted drinking water concentration limit of 0,1 g/L. Despite much recent research on atrazine, its risk assessment in the environment is still a major challenge because of the difficulty of establishing mass balances in the subsurface. To obtain a better insight into the fate of atrazine, we developed compound-specific stable isotope analysis (CSIA) for atrazine. CSIA has proven valuable for assessing organic contaminants in subsurface environments, on the one hand for source identification and on the other hand to trace (bio)chemical degradation reactions through isotope fractionation in the compounds. Such assessment is based on the Rayleigh equation and therein on the isotope enrichment factor ɛ, which must be determined experimentally beforehand. In ongoing work, we therefore measured carbon and nitrogen isotope fractionation associated with biotic hydrolsis of atrazine. C and N isotope enrichment factors were determined in resting cell experiments for Pseudomonas sp. ADP, Chelatobacter heintzii and Arthrobacter aurescens TC1, strains that hydrolyse atrazine in the initial transformation reaction. Carbon and nitrogen isotope enrichment factors were distinctly different between the bacterial strains. However, when plotting shifts in carbon isotope ratios versus shifts in nitrogen isotope ratios the slopes of the different degradation experiments coincided well. These results give evidence that all bacterial strains were carrying out the same initial biochemical degradation reaction, but that the associated isotope fractionation, as represented by the enrichment factors, was masked to a different extent owing to different rate determining steps prior to the isotopically sensitive bond cleavage (commitment to catalysis). Our study therefore illustrates the benefit of multi

  5. Degradation of atrazine by Frankia alni ACN14a: gene regulation, dealkylation, and dechlorination.

    PubMed

    Rehan, Medhat; Kluge, Martin; Fränzle, Stefan; Kellner, Harald; Ullrich, René; Hofrichter, Martin

    2014-07-01

    Atrazine is transformed to N-isopropylammelide through hydroxyatrazine as an intermediate as indicated by high-performance liquid chromatography/mass spectroscopy in culture filtrates of Frankia alni ACN14a and Frankia sp. EuI1c. Both Frankia strains have the ability to degrade atrazine via dechlorination and dealkylation and, subsequently, may be using it as a nitrogen and carbon source as detected here by increasing their growth patterns. Bioinformatic analysis of the Frankia genomes revealed that a potential gene cluster involved in atrazine decomposition contains three genes, namely, trzN (FRAAL1474 and FraEuI1c_5874), atzB (FRAAL1473 and FraEuI1c_5875), and atzR (FRAAL1471). The relative messenger RNA gene expression of the former genes was examined by qRT-PCR. The LysR-type transcriptional regulator atzR (FRAAL1471), which is expected to control the cluster expression, showed a 13-fold increase in the expression level under atrazine stress. Moreover, the putative adenosine aminohydrolase 3 atzB (FRAAL1473), which is expected to dealkylate the N-ethyl group of atrazine, showed also an increased expression by factor 16 with increased exposure. Eventually, the trzN (FRAAL1474) gene, which is predicted to encode a putative amidohydrolase catalyzing atrazine dechlorination, exhibited 31-fold increased expression. To our best knowledge, this is the first report about adenosine aminohydrolase 3 function in the dealkylation of the N-ethyl group from atrazine. PMID:24676750

  6. Estimation of upper centile concentrations using historical atrazine monitoring data from community water systems.

    PubMed

    Mosquin, Paul; Whitmore, Roy W; Chen, Wenlin

    2012-01-01

    A survey sampling approach is presented for estimating upper centiles of aggregate distributions of surface water pesticide measurements obtained from datasets with large sample sizes but variable sampling frequency. It is applied to three atrazine monitoring programs of Community Water Systems (CWS) that used surface water as their drinking water source: the nationwide Safe Drinking Water Act (SDWA) data, the Syngenta Voluntary Monitoring Program (VMP), and the Atrazine Monitoring Program (AMP).The VMP/AMP CWS were selected on the basis of atrazine monitoring history (CWS having at least one annual average concentration from SDWA ≥ 1.6 ppb atrazine since 1997 in the AMP). Estimates of the raw water 95th, 99th, and 99.9th centile atrazine concentrations for the VMP/AMP CWS are 4.82, 11.85, and 34.00 ppb, respectively. The corresponding estimates are lower for the finished drinking water samples, with estimates of 2.75, 7.94, and 22.66 ppb, respectively. Finished water centile estimates for the VMP/AMP CWS using only the SDWA data for these sites are consistent with the results. Estimates are provided for the April through July period and for CWS based on surface water source type (static, flowing, or mixed). Requisite sample sizes are determined using statistical tolerance limits, relative SE, and the Woodruff interval sample size criterion. These analyses provide 99.9% confidence that the existing data include the 99.9th centile atrazine concentration for CWS raw and finished water in the Midwest atrazine high-use areas and in the nationwide SDWA dataset. The general validity of this approach is established by a simulation that shows estimates to be close to target quantities for weights based on sampling probabilities or time intervals between samples. Recommendations are given for suitable effective sample sizes to reliably determine interval estimates. PMID:22565265

  7. In vitro atrazine-exposure inhibits human natural killer cell lytic granule release

    SciTech Connect

    Rowe, Alexander M.; Brundage, Kathleen M.; Barnett, John B. . E-mail: jbarnett@hsc.wvu.edu

    2007-06-01

    The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test this hypothesis, flow cytometry and fluorescent microscopy were employed to analyze NK cell-target cell co-cultures following atrazine exposure. These assays demonstrated no significant decrease in the level of target cell binding. However, the levels of NK intracellular lytic protein retained and the amount of lytic protein released were assessed following a 4-h incubation with K562 target cells. The relative level of intracellular lytic protein was 25-50% higher, and the amount of lytic protein released was 55-65% less in atrazine-treated cells than vehicle-treated cells following incubation with the target cells. These results indicate that ATR exposure inhibits the ability of NK cells to lyse target cells by blocking lytic granule release without affecting the ability of the NK cell to form stable conjugates with target cells.

  8. Degradation of atrazine by Frankia alni ACN14a: gene regulation, dealkylation, and dechlorination.

    PubMed

    Rehan, Medhat; Kluge, Martin; Fränzle, Stefan; Kellner, Harald; Ullrich, René; Hofrichter, Martin

    2014-07-01

    Atrazine is transformed to N-isopropylammelide through hydroxyatrazine as an intermediate as indicated by high-performance liquid chromatography/mass spectroscopy in culture filtrates of Frankia alni ACN14a and Frankia sp. EuI1c. Both Frankia strains have the ability to degrade atrazine via dechlorination and dealkylation and, subsequently, may be using it as a nitrogen and carbon source as detected here by increasing their growth patterns. Bioinformatic analysis of the Frankia genomes revealed that a potential gene cluster involved in atrazine decomposition contains three genes, namely, trzN (FRAAL1474 and FraEuI1c_5874), atzB (FRAAL1473 and FraEuI1c_5875), and atzR (FRAAL1471). The relative messenger RNA gene expression of the former genes was examined by qRT-PCR. The LysR-type transcriptional regulator atzR (FRAAL1471), which is expected to control the cluster expression, showed a 13-fold increase in the expression level under atrazine stress. Moreover, the putative adenosine aminohydrolase 3 atzB (FRAAL1473), which is expected to dealkylate the N-ethyl group of atrazine, showed also an increased expression by factor 16 with increased exposure. Eventually, the trzN (FRAAL1474) gene, which is predicted to encode a putative amidohydrolase catalyzing atrazine dechlorination, exhibited 31-fold increased expression. To our best knowledge, this is the first report about adenosine aminohydrolase 3 function in the dealkylation of the N-ethyl group from atrazine.

  9. Modeling toxic stress by atrazine in a marine consumer-resource system.

    PubMed

    De Hoop, Lisette; De Troch, Marleen; Hendriks, A Jan; De Laender, Frederik

    2013-04-01

    The present study combines short-term experiments with food chain modeling to explore the long-term effects of the herbicide atrazine on consumer-resource dynamics in a marine intertidal ecosystem. Short-term (28 d) lab experiments indicated that the intrinsic rate of increase (r) and carrying capacity (K) of the marine diatom Seminavis robusta decreased with increasing atrazine exposure. This decrease did not show the concave shape expected from the lifetime productivity for nonexposed diatoms and from single-species toxicity data in the literature but instead was described best by a linear model. These experimentally observed atrazine-induced decreases of r and K were used to parameterize a Rosenzweig-MacArthur model representing a simple food chain including the tested diatom and its grazer, the harpacticoid copepod Delavalia palustris var. palustris. Stable oscillation zoo-phytobenthos systems were produced at diatom exposures of 0, 100, and 150 µg/L atrazine. An atrazine concentration of 150 µg/L contributed to a 15% increase of the oscillation periods of both diatoms and copepods as well as a 52% reduction of oscillation amplitudes compared with the control situation. Although the amplitudes of copepods increased only 7% at 150 µg/L atrazine, the maximum and minimum copepod densities at that concentration were reduced 61 and 63%, respectively. The effects of atrazine on periodicity and amplitudes were robust to 20% changes in the food-chain model parameters that represented allometric relationships. The simulations in the present study suggest food chain-mediated indirect effects on zoobenthos populations, indicating a reduced diatom and copepod availability throughout the year.

  10. Effects of atrazine on fathead minnow in a short-term reproduction assay.

    PubMed

    Bringolf, Robert B; Belden, Jason B; Summerfelt, Robert C

    2004-04-01

    Atrazine is the most extensively used herbicide in the United States. Part-per-million concentrations of atrazine have been reported in agricultural runoff. It is detectable in surface waters and precipitation throughout the year, and it has been found in groundwater sources of drinking water. Recent studies indicate that atrazine may be a potent endocrine-disrupting compound in frogs exposed to part-per-billion (microg/L) concentrations. For these reasons, the effects of atrazine (5 and 50 microg/L) on several endpoints related to reproductive fitness were examined in fathead minnows (Pimephales promelas) in a 21-d static exposure. Estradiol (0.5 microg/L) was included as a positive-control treatment. Endpoints examined in adult fish during and after the exposures included survival, egg production, number of spawns, eggs/spawn, relative gonad weight, gonad histology, number of nuptial tubercles, and plasma vitellogenin concentration. Eggs produced during the exposures were hatched and reared in control water. The percentages of embryos fertilized and hatched as well as larval survival were evaluated. Decreasing trends were observed in relative testis weight, testis maturity, and percentage embryo fertilization. These trends suggest that further investigation is warranted, but the differences in these and other endpoints were not statistically significant in the atrazine-exposed fish. Nearly all endpoints concerning fish exposed to estradiol were significantly different from atrazine-exposed fish and control fish. These results suggest that atrazine did not have strong estrogenic effects in adult fathead minnows and did not cause overt reproductive toxicity at environmentally relevant concentrations.

  11. Biodegradation of atrazine by Rhodococcus sp. BCH2 to N-isopropylammelide with subsequent assessment of toxicity of biodegraded metabolites.

    PubMed

    Kolekar, Parag D; Phugare, Swapnil S; Jadhav, Jyoti P

    2014-02-01

    Atrazine is a persistent organic pollutant in the environment which affects not only terrestrial and aquatic biota but also human health. Since its removal from the environment is needed, atrazine biodegradation is achieved in the present study using the bacterium Rhodococcus sp. BCH2 isolated from soil, long-term treated with atrazine. The bacterium was capable of degrading about 75 % atrazine in liquid medium having pH 7 under aerobic and dark condition within 7 days. The degradation ability of the bacterium at various temperatures (20-60 °C), pH (range 3-11), carbon (glucose, fructose, sucrose, starch, lactose, and maltose), and nitrogen (ammonium molybdate, sodium nitrate, potassium nitrate, and urea) sources were studied for triumph optimum atrazine degradation. The results indicate that atrazine degradation at higher concentrations (100 ppm) was pH and temperature dependent. However, glucose and potassium nitrate were optimum carbon and nitrogen source, respectively. Atrazine biodegradation analysis was carried out by using high-performance thin-layer chromatography (HPTLC), Fourier transform infrared spectroscopy (FTIR), and liquid chromatography quadrupole time-of-flight (LC/Q-TOF-MS) techniques. LC/Q-TOF-MS analysis revealed formation of various intermediate metabolites including hydroxyatrazine, N-isopropylammelide, deisopropylhydroxyatrazine, deethylatrazine, deisopropylatrazine, and deisopropyldeethylatrazine which was helpful to propose biochemical degradation pathway of atrazine. Furthermore, the toxicological studies of atrazine and its biodegraded metabolites were executed on earthworm Eisenia foetida as a model organism with respect to enzymatic (SOD and Catalase) antioxidant defense mechanism and lipid peroxidation studies. These results suggest innocuous degradation of atrazine by Rhodococcus sp. BCH2 in nontoxic form. Therefore the Rhodococcus sp.BCH2 could prove a valuable source for the eco-friendly biodegradation of atrazine pesticide.

  12. Using polymer mats to biodegrade atrazine in groundwater: laboratory column experiments

    NASA Astrophysics Data System (ADS)

    Patterson, B. M.; Franzmann, P. D.; Davis, G. B.; Elbers, J.; Zappia, L. R.

    2002-02-01

    Large-scale column experiments were undertaken to evaluate the potential of in situ polymer mats to deliver oxygen into groundwater to induce biodegradation of the pesticides atrazine, terbutryn and fenamiphos contaminating groundwater in Perth, Western Australia. The polymer mats, composed of woven silicone (dimethylsiloxane) tubes and purged with air, were installed in 2-m-long flow-through soil columns. The polymer mats proved efficient in delivering dissolved oxygen to anaerobic groundwater. Dissolved oxygen concentrations increased from <0.2 mg l -1 to approximately 4 mg l -1. Degradation rates of atrazine in oxygenated groundwater were relatively high with a zero-order rate of 240-380 μg l -1 or a first-order half-life of 0.35 days. Amendment with an additional carbon source showed no significant improvement in biodegradation rates, suggesting that organic carbon was not limiting biodegradation. Atrazine degradation rates estimated in the column experiments were similar to rates determined in laboratory culture experiments, using pure cultures of atrazine-mineralising bacteria. No significant degradation of terbutryn or fenamiphos was observed under the experimental conditions within the time frames of the study. Results from these experiments indicate that remediation of atrazine in a contaminated aquifer may be achievable by delivery of oxygen using an in situ polymer mat system.

  13. Characterizing and modeling of extensive atrazine elution tailing for stable manure-amended agricultural soil.

    PubMed

    Akyol, Nihat Hakan

    2015-01-01

    Non-ideal sorption and extensive elution tailing behavior of atrazine was evaluated for an agricultural soil with and without stable manure amendment (10% by weight). A series of laboratory experiments showed that the sorption of atrazine was described by rate-limited, nonlinear reversible processes (Freundlich isotherm) for both non-amended and amended soil. Non-ideal transport of atrazine exhibited extensive low concentration elution tailing due to the most likely organic carbon fraction in the soil. This tailing behavior was more pronounced and extensive for soil with 10% stable-manure amendment. Two-site transport modeling analyses including non-linear sorption and rate-limited sorption-desorption provided a reasonably good match to the atrazine breakthrough curves but were unable to match the long-term concentration tailing, even for non-amended soil. A mathematical model incorporating nonlinear, rate-limited sorption/desorption described by a continuous-distribution function was used to successfully simulate atrazine transport early-time breakthrough and long-term concentration tailing for both non-amended and amended soil conditions. PMID:25303664

  14. Atrazine does not affect algal biomass or snail populations in microcosm communities at environmentally relevant concentrations.

    PubMed

    Baxter, Leilan R; Moore, Dana L; Sibley, Paul K; Solomon, Keith R; Hanson, Mark L

    2011-07-01

    The herbicide atrazine is a photosynthetic inhibitor used around the world in agricultural applications. Contamination of surface waters adjacent to treated areas can directly reduce growth of nontarget aquatic autotrophs, but the severity of impacts is highly dependent on species sensitivity and exposure concentration. Secondary effects resulting from macrophyte or phytoplankton decline may include an expansion of the more tolerant periphyton community. Recently, this shift in the autotrophic community has been proposed as a mechanism for increased rates of parasite infections in amphibians via augmented populations of aquatic snails which act as intermediate hosts to larval trematodes. To further clarify this relationship, an outdoor microcosm study was conducted to examine the effects of atrazine on primary production and snail populations over a range of environmentally relevant concentrations. In July 2009, 15 experimental ponds were treated to achieve initial concentrations of 0, 1, 10, 30, and 100 µg/L atrazine. Over a period of 73 d, measures were taken of macrophyte, phytoplankton, and periphyton biomass, growth, and fecundity of caged snails (Physella spp. and Stagnicola elodes) and free-living snails (Physella spp.). Except for declines in macrophyte biomass at the highest treatment level, no consistent relationships were found between atrazine concentration and any measured parameter. Comparison of these results with previous findings highlights the variability of responses to atrazine exposure between similarly constructed freshwater communities, even at concentrations up to 20 times higher than sustained environmental levels. PMID:21567448

  15. Discriminating between point and non-point sources of atrazine contamination of a sandy aquifer.

    PubMed

    Leterme, Bertrand; Vanclooster, Marnik; Rounsevell, Mark D A; Bogaert, Patrick

    2006-06-01

    This study analyses the sources of atrazine contamination in the Brusselian sandy aquifer of central Belgium. Atrazine has in the past been used for both agricultural and non-agricultural applications, but it is difficult to distinguish the contamination originating from these two sources. The spatial and temporal covariance of atrazine concentrations was studied by fitting semi-variogram models to monitoring data. Correlation ranges were found to be 600 m and 600-700 days, respectively. The results were used to apply a declustering algorithm before examining the distribution of atrazine concentrations measured in groundwater. Monitoring data appeared to follow a pseudo-lognormal distribution, as a lognormality test was negative. An inflexion point on the cumulative density function was thought to indicate the two different pollution processes, i.e., agricultural and non-agricultural contamination sources. A non-parametric one-way analysis of variance suggested that the vast majority of atrazine in groundwater was from non-agricultural, point sources. This was supported by the strong relationship between mean concentrations and land use, whilst other environmental variables, such as soil organic matter or groundwater depth, produced less meaningful results.

  16. Atrazine biodegradation in the lab and in the field: enzymatic activities and gene regulation

    PubMed Central

    Govantes, Fernando; Porrúa, Odil; García‐González, Vicente; Santero, Eduardo

    2009-01-01

    Summary Atrazine is an herbicide of the s‐triazine family that is used primarily as a nitrogen source by degrading microorganisms. While many catabolic pathways for xenobiotics are subjected to catabolic repression by preferential carbon sources, atrazine utilization is repressed in the presence of preferential nitrogen sources. This phenomenon appears to restrict atrazine elimination in nitrogen‐fertilized soils by indigenous organisms or in bioaugmentation approaches. The mechanisms of nitrogen control have been investigated in the model strain Pseudomonas sp. ADP. Expression of atzA, atzB ad atzC, involved in the conversion of atrazine in cyanuric acid, is constitutive. The atzDEF operon, encoding the enzymes responsible for cyanuric acid mineralization, is a target for general nitrogen control. Regulation of atzDEF involves a complex interplay between the global regulatory elements of general nitrogen control and the pathway‐specific LysR‐type regulator AtzR. In addition, indirect evidence suggests that atrazine transport may also be a target for nitrogen regulation in this strain. The knowledge about regulatory mechanisms may allow the design of rational bioremediation strategies such as biostimulation using carbon sources or the use of mutant strains impaired in the assimilation of nitrogen sources for bioaugmentation. PMID:21261912

  17. The impact of the herbicide atrazine on growth and photosynthesis of seagrass, Zostera marina (L.), seedlings.

    PubMed

    Gao, Yaping; Fang, Jianguang; Zhang, Jihong; Ren, Lihua; Mao, Yuze; Li, Bin; Zhang, Mingliang; Liu, Dinghai; Du, Meirong

    2011-08-01

    The impact of the widely used herbicide atrazine on seedling growth and photosynthesis of eelgrass was determined. The long-term impact of the herbicide atrazine (1, 10 and 100 μg/L) on growth of eelgrass Zostera marina (L.) seedlings, maintained in outdoor aquaria, was monitored over 4 weeks. Exposure to 10 μg/L atrazine resulted in significantly lower plant fresh weight and total chlorophyll concentration and up to 86.67% mortality at the 100 μg/L concentration. Short-term photosynthetic stress on eelgrass seedlings was determined and compared with adult eelgrass using chlorophyll fluorescence. The effective quantum yield in eelgrass seedlings was significantly depressed at all atrazine concentrations (2, 4, 8, 16, 32 and 64 μg/L) even within 2 h and remained at a lower level than for adult plants for each concentration. These results indicate that atrazine presents a potential threat to seagrass seedling functioning and that the impact is much higher than for adult plants.

  18. Atrazine-induced changes in the myocardial structure of peripubertal rats.

    PubMed

    Rajkovic, Vesna; Kovac, Renata; Koledin, Ivana; Matavulj, Milica

    2014-04-01

    The aim of the present study was to investigate the effect of atrazine (6-chloro-N(2)-ethyl-N(4)-isopropyl-1,3,5-triazine-2,4-diamine) on the left ventricle myocardium in juvenile/peripubertal male Wistar rats. Atrazine was administered orally at 50 or 200 mg/kg of body weight dose for 28 consecutive days. In order to assess possible structural alterations, tissue sections were examined histologically and then subjected to quantification analysis using stereological methods. The tissue specimens were routinely processed and stained with Mallory trichrome method in order to clearly distinguish muscle cells from the connective tissue components. A toluidine blue staining method was additionally used for the demonstration of mast cells. Statistically significant increase in length density and numerical density of capillaries were found at both the investigated doses of atrazine compared with the control. The increase in surface density and volume density of capillaries found at lower dosage of atrazine was significant in comparison with the control. The extensive mast cell degranulation was noted on the histological examination at both doses of the applied chemical. No significant changes were demonstrated for the stereological parameters of cardiomyocytes. Based on the available published data and the present results, it can be concluded that atrazine promoted angiogenesis in the rat myocardium, which might be partially mediated by mast cells.

  19. Fate and significance of major degradation products of atrazine in the soil environment

    SciTech Connect

    Coats, J.R.; Kruger, E.L.; Baluch, H.U.

    1995-12-01

    Complete metabolism studies using radiotracers were performed in the laboratory to determine the fate of atrazine and major degradation products, deethylatrazine, deisopropylatrazine, and hydroxyatrazine, in soil as affected by soil type, soil moisture, soil depth, and previous long-term atrazine history. Several soil factors have been shown to significantly affect the fate of these compounds in soil. Persistence of the 4 compounds was significantly increased in subsurface soils. Hydroxyatrazine was the most persistent of the 4 compounds in surface and subsurface soil. Desiopropylatrazine was the most susceptible to mineralization in both surface and subsurface soil. A higher amount of bound residues were formed in deisopropylatrazine-treated soils. Soil moisture significantly affects the persistence of atrazine, deethylatrazine and deisopropylatrazine with decreased persistence under saturated soil moisture conditions. Persistence of deethylatrazine was positively correlated with percent clay and negatively correlated with percent organic matter. In soils with long-term atrazine history, deethylatrazine undergoes enhanced degradation. In soil column studies, the relative movement of deethylatrazine was greater than that of atrazine.

  20. The combined effects of atrazine and lead (Pb): relative microbial activities and herbicide dissipation.

    PubMed

    Chen, Qinglin; Wang, Hui; Yang, Baoshan; He, Fei

    2014-04-01

    The experiment was conducted to investigate the effects of single and combined pollution from different concentrations of atrazine (field rate, FR, 2.0 mg kg(-1) and 5 times FR, 10 mg kg(-1)) and lead (Pb) (300 mg kg(-1) and 600 mg kg(-1)) on enzyme activity, basal soil respiration (BSR), and net nitrogen (N) mineralization (NNM) in soil after exposure for 0, 7, 14, 21, and 28 days. In addition, residual atrazine was measured in the samples of combined contamination. Results showed that the notable effects of either or both contaminants on the microbial activity and biological processes. Enzyme activity data demonstrated that the order of sensitivity to contamination was urease>invertase>catalase. BSR was strongly stimulated by atrazine/Pb at the early exposure (0-7 days for single contaminant and 7-14 days for combined contaminants). The stimulation effects on BSR were higher at low concentrations of the contamination (FR and Pb300). The combined treatments of 5FR+Pb600 inhibit BSR and NNM. Overall, the parameters associated with N cycling (urease and NNM) were more sensitive than others. Both Pb concentrations (300 and 600 mg/kg) had little influence on the dissipation of high concentrations of atrazine (5FR) during the 28-day-incubation. This study has provided useful information on potential ecotoxicology effects of combined contamination of atrazine and Pb on relative microbial biological process.

  1. Effects of atrazine on endocrinology and physiology in juvenile barramundi, Lates calcarifer (Bloch).

    PubMed

    Kroon, Frederieke J; Hook, Sharon E; Jones, Dean; Metcalfe, Suzanne; Osborn, Hannah L

    2014-07-01

    Exposure to certain environmental contaminants such as agricultural pesticides can alter normal endocrine and reproductive parameters in wild fish populations. Recent studies have found widespread pesticide contamination across the rivers that discharge into the Great Barrier Reef lagoon. Potential impacts on native fish species exposed to known endocrine disrupting chemicals such as atrazine, simazine, and diuron have not been assessed. In the present study, the authors examined the endocrine and physiological effects of short-term, acute exposure of environmentally relevant concentrations of analytical grade atrazine in juvenile barramundi (Lates calcarifer) in a controlled laboratory experiment. Expression of hepatic vitellogenin was not affected, supporting results of previous studies that showed that atrazine does not have a direct estrogenic effect via mediation of estrogen receptors. The lack of effect on brain cytochrome P19B (CYP19B) expression levels, combined with increases in testosterone (T) and 17β estradiol and a stable T:17β estradiol ratio, does not support the hypothesis that atrazine has an indirect estrogenic effect via modulation of aromatase expression. Gill ventilation rate, a measure of oxidative stress, did not change in contrast to other studies finding enhanced osmoregulatory disturbance and gill histopathology after atrazine exposure. To more closely reflect field conditions, the authors recommend that laboratory studies should focus more on examining the effects of commercial pesticide formulations that contain additional ingredients that have been found to be disruptive to endocrine function.

  2. Combined bioremediation of atrazine-contaminated soil by Pennisetum and Arthrobacter sp. strain DNS10.

    PubMed

    Zhang, Ying; Ge, Shijie; Jiang, Mingyue; Jiang, Zhao; Wang, Zhigang; Ma, Bingbing

    2014-05-01

    Strain DNS10 was isolated from the black soil collected from the northeast of China which had been cultivated with atrazine as the sole nitrogen source. Pennisetum is a common plant in Heilongjiang Province of China. The main objective of this paper was to evaluate the efficiency of plant-microbe joint interactions (Arthrobacter sp. DNS10 + Pennisetum) in atrazine degradation compared with single-strain and single-plant effects. Plant-microbe joint interactions degraded 98.10 % of the atrazine, while single strain and single plant only degraded 87.38 and 66.71 % after a 30-day experimental period, respectively. The results indicated that plant-microbe joint interactions had a better degradation effect. Meanwhile, we found that plant-microbe joint interactions showed a higher microbial diversity. The results of microbial diversity illustrated that the positive effects of cropping could improve soil microbial growth and activity. In addition, we planted atrazine-sensitive plants (soybean) in the soil after repair. The results showed that soybean growth in soil previously treated with the plant-microbe joint interactions treatment was better compared with other treatments after 20 days of growth. This was further proved that the soil is more conducive for crop cultivation. Hence, plant-microbe joint interactions are considered to be a potential tool in the remediation of atrazine-contaminated soil.

  3. Watershed regressions for pesticides (warp) models for predicting atrazine concentrations in Corn Belt streams

    USGS Publications Warehouse

    Stone, Wesley W.; Gilliom, Robert J.

    2012-01-01

    Watershed Regressions for Pesticides (WARP) models, previously developed for atrazine at the national scale, are improved for application to the United States (U.S.) Corn Belt region by developing region-specific models that include watershed characteristics that are influential in predicting atrazine concentration statistics within the Corn Belt. WARP models for the Corn Belt (WARP-CB) were developed for annual maximum moving-average (14-, 21-, 30-, 60-, and 90-day durations) and annual 95th-percentile atrazine concentrations in streams of the Corn Belt region. The WARP-CB models accounted for 53 to 62% of the variability in the various concentration statistics among the model-development sites. Model predictions were within a factor of 5 of the observed concentration statistic for over 90% of the model-development sites. The WARP-CB residuals and uncertainty are lower than those of the National WARP model for the same sites. Although atrazine-use intensity is the most important explanatory variable in the National WARP models, it is not a significant variable in the WARP-CB models. The WARP-CB models provide improved predictions for Corn Belt streams draining watersheds with atrazine-use intensities of 17 kg/km2 of watershed area or greater.

  4. Electrocatalytic hydrodehalogenation of atrazine in aqueous solution by Cu@Pd/Ti catalyst.

    PubMed

    Chen, Ya-Li; Xiong, Lu; Song, Xiang-Ning; Wang, Wei-Kang; Huang, Yu-Xi; Yu, Han-Qing

    2015-04-01

    Electrocatalytic hydrodehalogenation is a cost-effective approach to degrade halogenated organic pollutants in groundwater, and Pd-based catalysts have been found to be an efficient cathode material for this purpose. In this work, a novel Cu@Pd bimetallic catalyst loaded on Ti plate was prepared via combined electrodeposition and galvanic replacement for electrocatalytic hydrodehalogenation of atrazine, a typical halogenated pollutant. The obtained bimetallic catalyst with uniformly dispersed Pd nanoparticles possessed a large electrochemically active surface area of 572 cm2. The Cu@Pd/Ti cathode exhibited a higher electrocatalytic efficiency towards atrazine reduction than the individual Pd/Ti or Cu/Ti cathodes, and achieved up to 91.5% within 120 min under a current density of 1 mA cm(-2). Such an electrocatalytic reduction followed pseudo-first-order kinetics with a rate constant of 0.0214 min(-1). Atrazine was selectively transformed to dechlorinated atrazine, and its degradation pathway was identified. Current density was found to have a critical influence on the atrazine reduction due to the competitive hydrogen evolution reaction at a higher current density. The fabricated bimetallic catalyst also exhibited a good stability. This work provides an efficient and stable electrocatalyst for chlorinated contaminate removal and groundwater remediation.

  5. Oxidative stress response induced by atrazine in Palaemonetes argentinus: the protective effect of vitamin E.

    PubMed

    Griboff, Julieta; Morales, David; Bertrand, Lidwina; Bonansea, Rocío Inés; Monferrán, Magdalena Victoria; Asis, Ramón; Wunderlin, Daniel Alberto; Amé, María Valeria

    2014-10-01

    The widespread contamination and persistence of the herbicide atrazine residues in the environment resulted in the exposure of non-target organisms. The present study was undertaken to investigate the effect of atrazine in the response of oxidative stress biomarkers in the freshwater shrimp Palaemonetes argentinus and the protective effect of vitamin-E against atrazine-induced toxicity. Therefore, two batches of P. argentinus were fed for 21 days with a commercial food enriched in proteins (D1) or with D2, composed of D1 enriched with vitamin-E (6.8 and 16.0mg% of vitamin-E, respectively). Subsequently, half of the individuals of each group were exposed to atrazine (0.4mgL(-1)) for 24h and the others remained as controls. Atrazine promoted oxidative stress response in P. argentinus fed with D1 as indicated by enhanced H2O2 content and induction of superoxide dismutase, glutathione-S-transferases and glutathione reductase. This antioxidant activity would prevent the increment of thiobarbituric acid reactive substances in the shrimp tissues. P. argentinus fed with D2 reversed the response of the biomarkers measured. However, the activation of antioxidants response had an energetic cost, which was revealed by a decrease in lipids storage in shrimps. These results show the modulatory effect of vit-E on oxidative stress and its potential use as an effective antioxidant to be applied in chemoprotection strategies during aquaculture.

  6. Characterizing and modeling of extensive atrazine elution tailing for stable manure-amended agricultural soil.

    PubMed

    Akyol, Nihat Hakan

    2015-01-01

    Non-ideal sorption and extensive elution tailing behavior of atrazine was evaluated for an agricultural soil with and without stable manure amendment (10% by weight). A series of laboratory experiments showed that the sorption of atrazine was described by rate-limited, nonlinear reversible processes (Freundlich isotherm) for both non-amended and amended soil. Non-ideal transport of atrazine exhibited extensive low concentration elution tailing due to the most likely organic carbon fraction in the soil. This tailing behavior was more pronounced and extensive for soil with 10% stable-manure amendment. Two-site transport modeling analyses including non-linear sorption and rate-limited sorption-desorption provided a reasonably good match to the atrazine breakthrough curves but were unable to match the long-term concentration tailing, even for non-amended soil. A mathematical model incorporating nonlinear, rate-limited sorption/desorption described by a continuous-distribution function was used to successfully simulate atrazine transport early-time breakthrough and long-term concentration tailing for both non-amended and amended soil conditions.

  7. Manganese dioxide as a catalyst for oxygen-independent atrazine dealkylation

    SciTech Connect

    Wang, D.; Spiro, T.G.; Shin, J.Y.; Cheney, M.A.; Sposito, G.

    1999-09-15

    The herbicide atrazine is widely distributed in the environment, and its reactivity with soil minerals is an important issue. The authors have studied atrazine degradation on the surface of synthetic hydrous (10% H{sub 2}O) {delta}-MnO{sub 2} (birnessite) using UV resonance Raman spectroscopy and gas chromatography. The products are mainly mono- and didealkyl atrazine. Atrazine disappearance is rapid, independent of whether O{sub 2} is present or not. MnO{sub 2} reduction is a minor reaction, and the alkyl chains are converted mainly to the alkenes, in a nonredox process. A novel dealkylation mechanism is proposed involving proton transfer to Mn(IV)-stabilized oxo and imido bonds. When O{sub 2} is present, olefin oxidation and ring mineralization are also observed as secondary reactions in addition to those discussed above. Thus {delta}-MnO{sub 2}, a common soil constituent, is found to promote efficient N-dealkylation of the herbicide atrazine at 30 C, via a nonoxidative mechanism.

  8. Atrazine molecular imprinted polymers: comparative analysis by far-infrared and ultraviolet induced polymerization.

    PubMed

    Chen, Jun; Bai, Lian-Yang; Liu, Kun-Feng; Liu, Run-Qiang; Zhang, Yu-Ping

    2014-01-06

    Atrazine molecular imprinted polymers (MIPs) were comparatively synthesized using identical polymer formulation by far-infrared (FIR) radiation and ultraviolet (UV)-induced polymerization, respectively. Equilibrium binding experiments were carried out with the prepared MIPs; the results showed that MIP(uv) possessed specific binding to atrazine compared with their MIP(FIR) radiation counterparts. Scatchard plot's of both MIPs indicated that the affinities of the binding sites in MIPs are heterogeneous and can be approximated by two dissociation-constants corresponding to the high- and low-affinity binding sites. Moreover, several common pesticides including atrazine, cyromazine, metamitron, simazine, ametryn, terbutryn were tested to determine their specificity, similar imprinting factor (IF) and different selectivity index (SI) for both MIPs. Physical characterization of the polymers revealed that the different polymerization methods led to slight differences in polymer structures and performance by scanning electron microscope (SEM), Fourier transform infrared absorption (FT-IR), and mercury analyzer (MA). Finally, both MIPs were used as selective sorbents for solid phase extraction (SPE) of atrazine from lake water, followed by high performance liquid chromatography (HPLC) analysis. Compared with commercial C18 SPE sorbent (86.4%-94.8%), higher recoveries of atrazine in spiked lake water were obtained in the range of 90.1%-97.1% and 94.4%-101.9%, for both MIPs, respectively.

  9. Atrazine does not affect algal biomass or snail populations in microcosm communities at environmentally relevant concentrations.

    PubMed

    Baxter, Leilan R; Moore, Dana L; Sibley, Paul K; Solomon, Keith R; Hanson, Mark L

    2011-07-01

    The herbicide atrazine is a photosynthetic inhibitor used around the world in agricultural applications. Contamination of surface waters adjacent to treated areas can directly reduce growth of nontarget aquatic autotrophs, but the severity of impacts is highly dependent on species sensitivity and exposure concentration. Secondary effects resulting from macrophyte or phytoplankton decline may include an expansion of the more tolerant periphyton community. Recently, this shift in the autotrophic community has been proposed as a mechanism for increased rates of parasite infections in amphibians via augmented populations of aquatic snails which act as intermediate hosts to larval trematodes. To further clarify this relationship, an outdoor microcosm study was conducted to examine the effects of atrazine on primary production and snail populations over a range of environmentally relevant concentrations. In July 2009, 15 experimental ponds were treated to achieve initial concentrations of 0, 1, 10, 30, and 100 µg/L atrazine. Over a period of 73 d, measures were taken of macrophyte, phytoplankton, and periphyton biomass, growth, and fecundity of caged snails (Physella spp. and Stagnicola elodes) and free-living snails (Physella spp.). Except for declines in macrophyte biomass at the highest treatment level, no consistent relationships were found between atrazine concentration and any measured parameter. Comparison of these results with previous findings highlights the variability of responses to atrazine exposure between similarly constructed freshwater communities, even at concentrations up to 20 times higher than sustained environmental levels.

  10. Environmentally Realistic Exposure to the Herbicide Atrazine Alters Some Sexually Selected Traits in Male Guppies

    PubMed Central

    Shenoy, Kausalya

    2012-01-01

    Male mating signals, including ornaments and courtship displays, and other sexually selected traits, like male-male aggression, are largely controlled by sex hormones. Environmental pollutants, notably endocrine disrupting compounds, can interfere with the proper functioning of hormones, thereby impacting the expression of hormonally regulated traits. Atrazine, one of the most widely used herbicides, can alter sex hormone levels in exposed animals. I tested the effects of environmentally relevant atrazine exposures on mating signals and behaviors in male guppies, a sexually dimorphic freshwater fish. Prolonged atrazine exposure reduced the expression of two honest signals: the area of orange spots (ornaments) and the number of courtship displays performed. Atrazine exposure also reduced aggression towards competing males in the context of mate competition. In the wild, exposure levels vary among individuals because of differential distribution of the pollutants across habitats; hence, differently impacted males often compete for the same mates. Disrupted mating signals can reduce reproductive success as females avoid mating with perceptibly suboptimal males. Less aggressive males are at a competitive disadvantage and lose access to females. This study highlights the effects of atrazine on ecologically relevant mating signals and behaviors in exposed wildlife. Altered reproductive traits have important implications for population dynamics, evolutionary patterns, and conservation of wildlife species. PMID:22312428

  11. DNA damage and effects on antioxidative enzymes in zebra fish (Danio rerio) induced by atrazine.

    PubMed

    Zhu, Lu-Sheng; Shao, Bo; Song, Yan; Xie, Hui; Wang, Jun; Wang, Jin-Hua; Liu, Wei; Hou, Xin-Xin

    2011-01-01

    The effect of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1, 3, 5-triazine) on the activity of some antioxidative enzymes (superoxide dismutase, SOD; catalase, CAT; and guaiacol peroxidase, POD) and DNA damage induced by atrazine were investigated in zebra fish (Danio rerio). Zebra fish were exposed to four different concentrations of atrazine (0, 2.5, 5, and 10 mg/L) for 7, 14, and 21 days, with three replicates of 10 fishes per treatment. Compared to the controls, the SOD activity in the 2.5 mg/L treatment was markedly stimulated in 21 days, while the SOD activities in the 5 mg/L treatment was stimulated at first and then inhibited. The change of CAT activity at 2.5 mg/L was similar to the SOD activity at 2.5 mg/L. The POD activities in the 2.5, 5, and 10 mg/L treatment were markedly higher on days 14 and 21 compared with the controls. The olive tail moments of single-cell gel electrophoresis (SCGE) of zebra fish enhanced after treatment of different doses on days 7, 14, and 21, and significant differences were found compared to the controls. In conclusion, these findings showed the effect regularity of atrazine to zebra fish, and also provide the basis for the future research of adverse effects induced by atrazine in aquatic ecosystems.

  12. Atrazine Molecular Imprinted Polymers: Comparative Analysis by Far-Infrared and Ultraviolet Induced Polymerization

    PubMed Central

    Chen, Jun; Bai, Lian-Yang; Liu, Kun-Feng; Liu, Run-Qiang; Zhang, Yu-Ping

    2014-01-01

    Atrazine molecular imprinted polymers (MIPs) were comparatively synthesized using identical polymer formulation by far-infrared (FIR) radiation and ultraviolet (UV)-induced polymerization, respectively. Equilibrium binding experiments were carried out with the prepared MIPs; the results showed that MIPuv possessed specific binding to atrazine compared with their MIPFIR radiation counterparts. Scatchard plot’s of both MIPs indicated that the affinities of the binding sites in MIPs are heterogeneous and can be approximated by two dissociation-constants corresponding to the high-and low-affinity binding sites. Moreover, several common pesticides including atrazine, cyromazine, metamitron, simazine, ametryn, terbutryn were tested to determine their specificity, similar imprinting factor (IF) and different selectivity index (SI) for both MIPs. Physical characterization of the polymers revealed that the different polymerization methods led to slight differences in polymer structures and performance by scanning electron microscope (SEM), Fourier transform infrared absorption (FT-IR), and mercury analyzer (MA). Finally, both MIPs were used as selective sorbents for solid phase extraction (SPE) of atrazine from lake water, followed by high performance liquid chromatography (HPLC) analysis. Compared with commercial C18 SPE sorbent (86.4%–94.8%), higher recoveries of atrazine in spiked lake water were obtained in the range of 90.1%–97.1% and 94.4%–101.9%, for both MIPs, respectively. PMID:24398982

  13. Cyanazine, Atrazine, and Their Metabolites as Geochemical Indicators of Contaminant Transport in the Mississippi River

    USGS Publications Warehouse

    Meyer, M.T.; Thurman, E.M.; Goolsby, D.A.

    1996-01-01

    The geochemical transport of cyanazine and its metabolite cyanazine amide (CAM) was compared to atrazine and its metabolite deethylatrazine (DEA) at three sites in the Mississippi River basin during 1992 and six sites during 1993. The floods of 1993 caused an uninterrupted exponential decline in herbicide concentrations; whereas, in 1992 herbicide concentrations varied mostly in response to two discrete discharge pulses in the spring and midsummer and were stable during an extended period of summer low-flow. Concentration half-lives calculated from the 1993 data for atrazine were approximately twice those of cyanazine at all sites. The half-life for atrazine and cyanazine was shortest, 22 and 14 days, respectively at the Mississippi River at Clinton, Ill. - the farthest upstream site - and longest, 42 and 22 days, respectively, at the Baton Rouge, La. site - the farthest downstream site. The concentration of CAM exceeded the concentration of DEA through September at all sites where the mean ratio of atrazine-to-cyanazine (ACR) was less than 4.0. The ratio of CAM-to-cyanazine (CAMCR) increased from 0.2 to more than 1.0 and the ratio of DEA-to-atrazine (DAR) increased from less than 0.1 to 0.3 from application in May through early to mid-July. Temporal changes in the CAMCR were used to identify pre- and post-application "slugs" of water transported along the reaches of the Mississippi River.

  14. Risk-Cost-Benefit Analysis Of Atrazine In Drinking Water From Agricultural Activities

    NASA Astrophysics Data System (ADS)

    Aklilu, T. A.; Jagath, K. J.; Arthur, C. J.

    2004-12-01

    This study provides a new methodology for investigating the trade-offs between the health risks and economic benefits of using atrazine in the agricultural sector and a more holistic insight to pesticide management issues. Regression models are developed to predict the stream atrazine concentrations and finished water atrazine concentration at high-risk community water supplies in the US using surface water. The predicted finished water atrazine concentrations are then used in health risk assessment. The computed health risks are compared with the total surplus in the US corn market for different atrazine application rates using the demand and supply functions developed in this work. Analysis of different scenarios with consumer price premiums (preferences) for chemical-free to reduced chemical corn provided interesting results on the potential for future pesticide and land use management. This is an interdisciplinary work that has attempted to integrate and consider the interaction between weed sciences, economics, water quality, human health risk and human reaction to changes in different pesticide use scenarios. The results showed that this methodology provides a scientific framework for future decision-making and policy evaluation in pesticide management, especially when better regional and national data are available.

  15. Using polymer mats to biodegrade atrazine in groundwater: laboratory column experiments.

    PubMed

    Patterson, B M; Franzmann, P D; Davis, G B; Elbers, J; Zappia, L R

    2002-02-01

    Large-scale column experiments were undertaken to evaluate the potential of in situ polymer mats to deliver oxygen into groundwater to induce biodegradation of the pesticides atrazine, terbutryn and fenamiphos contaminating groundwater in Perth, Western Australia. The polymer mats, composed of woven silicone (dimethylsiloxane) tubes and purged with air, were installed in 2-m-long flow-through soil columns. The polymer mats proved efficient in delivering dissolved oxygen to anaerobic groundwater. Dissolved oxygen concentrations increased from <0.2 mg l(-1) to approximately 4 mg l(-1). Degradation rates of atrazine in oxygenated groundwater were relatively high with a zero-order rate of 240-380 microg l(-1) or a first-order half-life of 0.35 days. Amendment with an additional carbon source showed no significant improvement in biodegradation rates, suggesting that organic carbon was not limiting biodegradation. Atrazine degradation rates estimated in the column experiments were similar to rates determined in laboratory culture experiments, using pure cultures of atrazine-mineralising bacteria. No significant degradation of terbutryn or fenamiphos was observed under the experimental conditions within the time frames of the study. Results from these experiments indicate that remediation of atrazine in a contaminated aquifer may be achievable by delivery of oxygen using an in situ polymer mat system.

  16. ATRAZINE ECOLOGICAL EFFECTS ASSESSMENT FOR OPP LEVEL OF CONCERN AND OW WATER QUALITY CRITERION FOR AQUATIC LIFE

    EPA Science Inventory

    Atrazine is a relatively water-soluble and persistent herbicide that can reach concentrations of possible ecological concern for aquatic plants in vulnerable watersheds in regions with high agricultural usage of atrazine. As a consequence, the U.S. EPA Office of Water is current...

  17. Biomarker Analysis of American Toad (Anaxyrus Americanus) and Grey Tree Frog (Hyla Versicolor) Tadpoles Following Exposure to Atrazine

    EPA Science Inventory

    To better understand the mode of action of atrazine in amphibians, we utilized mass spectrometry-based metabolomics to investigate the biochemical changes in two species of larval amphibians exposed to atrazine. Our objectives were to 1) Use changes in endogenous metabolites to f...

  18. Predicting where enhanced atrazine degradation will occur based on soil pH and herbicide use history

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil bacteria on all continents except Antartica have developed the ability to rapidly degrade the herbicide atrazine, a phenomenon referred to as enhanced degradation. The agronomic significance of enhanced degradation is the potential for reduced residual weed control with atrazine in Corn, Sorgh...

  19. Seasonal atrazine contamination of drinking water in pig-breeding farm surroundings in agricultural and industrial areas of Croatia.

    PubMed

    Gojmerac, T; Kartal, B; Bilandzic, N; Roic, B; Rajkovic-Janje, R

    1996-02-01

    Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) a s-triazine herbicide, has been widely used in Croatian agriculture. Due to atrazine extensive use and its biodegradation in nature within at least one year (Klassen and Kodoum 1979), atrazine residues are found in ground, surface, drain and drinking water (Vidacek et al. 1994; Gojmerac et al. 1994). Groundwater downgradient from atrazine treated fields may show seasonal concentration peaks which could exceed the safe level (Wehtje et al. 1983). Therefore, the use of atrazine includes permanent control of its residues in water, particularly in relation to its use as a herbicidal chemical and groundwater contamination (Graham 1991). Furthermore, the presence of atrazine in the environment and its possible ingestion via the water, food and feed chain, may present a risk for the animal and human health. The analysis of atrazine residues in soil can be performed by either colorimetry or high performance liquid chromatography (HPLC) (Vickrey et al. 1980), and in water, soil and food by immunoassay in comparison with HPLC or gas chromatography/mass spectrometry (GS-MS) (Bushway et al. 1988; Bushway et al. 1989; Bushway et al. 1992; Thurman et al. 1990). We describe the use of enzyme-linked immunosorbent assay (ELISA) for one-year seasonal monitoring of atrazine residues in drinking water from two differently situated pig-breeding farms (agricultural and industrial areas) in Croatia. Results obtained by ELISA were compared to those produced by HPLC.

  20. Negative Effects of Low Dose Atrazine Exposure on the Development of Effective Immunity to FV3 in Xenopus laevis

    PubMed Central

    Sifkarovski, Jason; Grayfer, Leon; De Jesús Andino, Francisco; Lawrence, B. Paige; Robert, Jacques

    2014-01-01

    The recent dramatic increase of the prevalence and range of amphibian host species and populations infected by ranaviruses such as Frog Virus 3 (FV3) raises concerns about the efficacies of amphibian antiviral immunity. In this context, the potential negative effects of water contaminants such as the herbicide atrazine, at environmentally relevant levels, on host antiviral immunity remains unclear. Here we describe the use of the amphibian Xenopus laevis as an ecotoxiciology platform to elucidate the consequences of exposure to ecologically relevant doses of atrazine on amphibian antiviral immunity. X. laevis were exposed at tadpole and adult stages as well as during metamorphosis to atrazine (range from 0.1 to 10.0 ppb) prior to infection with FV3. Quantitative analysis of gene expression revealed significant changes in the pro-inflammatory cytokine, TNF-α and the antiviral type I IFN gene in response to FV3 infection. This was most marked in tadpoles that were exposed to atrazine at doses as low 0.1 ppb. Furthermore, atrazine exposure significantly compromised tadpole survival following FV3 infections. In contrast, acute atrazine exposure of mature adult frogs did not induce detectable effects on anti-FV3 immunity, but adults that were exposed to atrazine during metamorphosis exhibited pronounced defects in FV3-induced TNF-α gene expression responses and slight diminution in type I IFN gene induction. Thus, even at low doses, atrazine exposure culminates in impaired development of amphibian antiviral defenses. PMID:24984115

  1. Understanding the Effects of Atrazine on Steroidogenesis in rat granulosa and H295R adrenal cortical carcinoma cells

    EPA Science Inventory

    Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) was introduced in the 1950s as a broad spectrum herbicide, and remains one of the most widely used herbicides in the United States. Several studies have suggested that atrazine modifies steroidogenesis and may disrupt r...

  2. Negative effects of low dose atrazine exposure on the development of effective immunity to FV3 in Xenopus laevis.

    PubMed

    Sifkarovski, Jason; Grayfer, Leon; De Jesús Andino, Francisco; Lawrence, B Paige; Robert, Jacques

    2014-11-01

    The recent dramatic increase of the prevalence and range of amphibian host species and populations infected by ranaviruses such as Frog Virus 3 (FV3) raises concerns about the efficacies of amphibian antiviral immunity. In this context, the potential negative effects of water contaminants such as the herbicide atrazine, at environmentally relevant levels, on host antiviral immunity remains unclear. Here we describe the use of the amphibian Xenopus laevis as an ecotoxicology platform to elucidate the consequences of exposure to ecologically relevant doses of atrazine on amphibian antiviral immunity. X. laevis were exposed at tadpole and adult stages as well as during metamorphosis to atrazine (range from 0.1 to 10.0 ppb) prior to infection with FV3. Quantitative analysis of gene expression revealed significant changes in the pro-inflammatory cytokine, TNF-α and the antiviral type I IFN gene in response to FV3 infection. This was most marked in tadpoles that were exposed to atrazine at doses as low 0.1 ppb. Furthermore, atrazine exposure significantly compromised tadpole survival following FV3 infections. In contrast, acute atrazine exposure of mature adult frogs did not induce detectable effects on anti-FV3 immunity, but adults that were exposed to atrazine during metamorphosis exhibited pronounced defects in FV3-induced TNF-α gene expression responses and slight diminution in type I IFN gene induction. Thus, even at low doses, atrazine exposure culminates in impaired development of amphibian antiviral defenses.

  3. Atrazine immobilization on sludge derived biochar and the interactive influence of coexisting Pb(II) or Cr(VI) ions.

    PubMed

    Zhang, Weihua; Zheng, Juan; Zheng, Pingping; Qiu, Rongliang

    2015-09-01

    Sludge derived biochars (SDBCs) may have the potential to simultaneously remove heavy metals and organic contaminants in relation to their various active sorption sites for both metal ions and organic compounds. SDBCs have been proven to provide a considerable capacity for immobilizing Pb(II) and Cr(VI) ions in solution, and in this study their ability to sorb atrazine, in addition to their corresponding interactive influences with coexisting metal ions, is extensively investigated. The results indicate that all atrazine adsorption isotherms fit well with the Freundlich equation, and the greatest value of 16.8 mg g(-1) sorption capacity occurred with SDBCs pyrolyzed at 400°C for 2h. The slow sorption kinetics fit well with the Lagergren's 2nd order reaction, and depend upon the initial atrazine concentration, indicating the significance of a site-specific process. The ionic strength-dependence of the atrazine adsorption behavior further consolidates the involvement of the mechanism of the H-bond with hydroxyl groups on SDBC. However, when Pb(II)/Cr(VI) metal ions coexist in solution, they substantially suppress atrazine adsorption, probably because the inner complex between the hydroxyl groups on SDBCs and Pb(II)/Cr(III) ions intrude the weak H-bond with atrazine. As a result, metal adsorption was found to be unaffected by the coexisting atrazine. Therefore, although SDBC is applicable for atrazine removal/immobilization in most of environmentally relevant conditions, a two-step process may be required if heavy metal ions coexist.

  4. Monitoring of atrazine in the mainstream, major tributaries and streams of the Chesapeake Bay watershed: Ecological significance

    SciTech Connect

    Hall, L.W. Jr.; Anderson, R.D.

    1996-10-01

    The goal of this study was to provide exposure data for the atrazine in the mainstream tributaries of the Chesapeake Bay watershed. In 1995, ten stations were sampled four times per year. Atrazine was also measured at 4 hour intervals for 72 hours at all stream sites during one rain event during the spring. Results are described.

  5. Analysis of atrazine and four degradation products in the pore water of the vadose zone, central Indiana

    USGS Publications Warehouse

    Panshin, S.Y.; Carter, D.S.; Bayless, E.R.

    2000-01-01

    A new method is described for the analysis of atrazine and four of its degradation products (desethylatrazine, deisopropylatrazine, didealkylatrazine, and hydroxyatrazine) in water. This method uses solid- phase extraction on a graphitized carbon black cartridge, derivatization of the eluate with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), and analysis by gas chromatography/mass spectrometry (GC/MS). This method was used to analyze lysimeter samples collected from a field in central Indiana in 1994 and 1995. Atrazine and its degradation products were transported rapidly through the vadose zone. Maximum values of atrazine ranged from 2.61 to 8.44 ??g/L and occurred from 15 to 57 days after application. Maximum concentrations of the degradation products occurred from 11 to 140 days after atrazine application. The degradation products were more persistent than atrazine in pore water. Desethylatrazine was the dominant degradation product detected in the first year, and didealkylatrazine was the dominant degradation product detected in the second year. Concentrations of atrazine and the degradation products sorbed onto soil were estimated; maximum concentrations ranged from 7.3 to 24 ??g/kg for atrazine and were less than 5 ??g/kg for all degradation products. Degradation of atrazine and transport of all five compounds were simulated by the vadose zone flow model LEACHM. LEACHM was run as a Darcian-flow model and as a non-Darcian-flow model.

  6. DNA damage and effects on glutathione-S-transferase activity induced by atrazine exposure in zebrafish (Danio rerio).

    PubMed

    Zhu, Lusheng; Dong, Xiaoli; Xie, Hui; Wang, Jun; Wang, Jinhua; Su, Jun; Yu, Changwei

    2011-10-01

    This study was undertaken to investigate the protective effect of atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-S-triazine) on the activity of glutathione-S-transferase (GST) and DNA damage in males and females of adult zebrafish (Danio rerio). Zebrafish were exposed to control and three treatments (0.01, 0.1, and 1 mg/L) of atrazine for 5, 10, 15, 20, and 25 days. The results indicated that, for males, the GST activity at lower atrazine concentrations (0.01 and 0.1 mg/L) was markedly higher than that of the controls throughout the duration of the experiment while there was a significant inhibition of the GST activity at 1 mg/L atrazine at days 5 and 20. For females, a significant increase was detected at 0.1 mg/L on the days 5 and 15 and at 0.01 mg/L on day 20. The DNA damage in zebrafish was evaluated using the comet assay; the olive tail moments obtained for hepatopancreas were enhanced after treatment with different concentrations of atrazine on days 5, 10, 15, 20, and 25. The DNA damage increased with increasing atrazine concentrations, indicating that genotoxicity of atrazine and significant differences was found compared to the controls. In conclusion, these findings provide further evidence of the effects of atrazine on aquatic ecosystems.

  7. Enhanced Degradation and Soil Depth Effects on the Fate of Atrazine and Major Metabolites in Colorado and Mississippi Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report’s aim is to inform modelers of the differences in atrazine fate between s-triazine-adapted and non-adapted soils as a function of depth in the profile, and to recommend input values for pesticide process sub-modules. The specific objectives of this study were to estimate the atrazine-mi...

  8. Behavioural and histological effects of atrazine on freshwater molluscs (Physa acuta Drap. and Ancylus fluviatilis Müll. Gastropoda).

    PubMed

    Rosés, N; Poquet, M; Muñoz, I

    1999-01-01

    This study examines the direct and indirect effects of atrazine on two grazer species--Physa acuta and Ancylus fluviatilis--as assessed by changes in mortality rates, biomass, searching behaviour and histological properties. No direct effects were observed in the acute toxicity test (48 h) with 0.02, 0.2, 2, 10 and 20 mg l(-1) of atrazine. A chronic toxicity test (18 days) performed in six experimental channels with 15 microg l(-1) of atrazine showed significant changes in grazer behaviour, increased searching velocity and different movement patterns in animals exposed to herbicide. No significant effects were observed in rates of mortality and biomass. Kidney cells of Physa acuta displayed an important cell lysis when animals were exposed to 0.1 mg l(-1) of atrazine for 10 days, and this effect was not reversed after a decontamination process. These results provide evidence of behavioural and structural changes in freshwater molluscs due to a subacute atrazine concentration.

  9. The effects of gestational and chronic atrazine exposure on motor behaviors and striatal dopamine in male Sprague-Dawley rats.