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1.
Chemosphere ; 265: 129108, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33277001

RESUMO

The consecutive application of herbicide acetochlor has resulted in the widespread drug resistance of weeds and the high risks to environment and human health. To assess environmental behaviors and minimal dosage of acetochlor application in the realistic soil, we systematically investigated the acetochlor adsorption/desorption, mobility, leaching, degradation, weed bioavailability and lethal dosage of acetochlor in three soil types including Nanjing (NJ), Yancheng (YC) and Yingtan (YT). Under the same conditions (60% moisture and darkness), acetochlor had a half-life of disappearance 3 days in NJ, 4.9 days in YC and 25.7 days in YT soils. The HRLC-Q-TOF-MS/MS analyses identified ten metabolites and eight conjugates generated through dealkylation, hydroxylation, thiol conjugation and glycosylation pathways. The acetochlor adsorption to soils ranked in the order of YT > YC > NJ and was committed to the Freundlich model. By examining the effects of soil moisture, microbial activity, illumination/darkness, etc. on acetochlor degradation in soils, we showed that the chemical metabolisms could undergo multiple processes through soil microbial degradation, hydrolysis or photolysis-mediated mechanisms. The longitudinal migration assay revealed that acetochlor leaching ability in the three soils was YT > YC > NJ, which was negatively associated with the order of adsorption behavior. Four kinds of weed were grown in the acetochlor-contaminated NJ soil. The lethal concentrations for the weed plantlets were 0.16-0.3 mg/kg, much lower than the dosage of realistic field application. Overall, our work provided novel insights into the mechanism for acetochlor behaviors in soils, the natural degradation process in the environment, and the lethal concentration to the tested weed plants.


Assuntos
Herbicidas , Poluentes do Solo , Disponibilidade Biológica , Herbicidas/análise , Herbicidas/toxicidade , Humanos , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Espectrometria de Massas em Tandem , Toluidinas/análise , Toluidinas/toxicidade
2.
Sci Total Environ ; 756: 143993, 2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33310222

RESUMO

Wetland biofilms were exposed to the herbicide glyphosate via in situ field exposures and controlled microcosm experiments to measure bioconcentration and metabolism of glyphosate by biofilm organisms. Concentrations of glyphosate in biofilms were two to four orders of magnitude higher than the surrounding water, bioconcentration factors averaged 835 and 199 L·kg-1 in field- and lab-exposed biofilms, respectively. Glyphosate in water where it had been detected in biofilms at field-exposed sites ranged from below detection (<1 µg·L-1) up to 130 µg·L-1. Bioconcentration of glyphosate in biofilms was inversely proportional to concentrations in the surrounding water, and the retention kinetics were similar to both adsorption and enzymatic models. Microorganisms present in both the water and biofilms metabolized glyphosate to its primary breakdown product aminomethyl phosphonic acid (AMPA), with increased rates of breakdown in and around the biofilms. Photosynthetic efficiency of the algae within the biofilms was not affected by 24 h controlled glyphosate exposures. Our results demonstrate the role of biofilms in improving wetland water quality by removing contaminants like glyphosate, but also as a potential exposure route to higher trophic levels via consumption. Due to bioconcentration of pesticides, exposure risk to organisms consuming or living in biofilms may be much higher than indicated by concentrations in ambient water samples.


Assuntos
Herbicidas , Poluentes Químicos da Água , Bioacumulação , Biofilmes , Glicina/análogos & derivados , Herbicidas/análise , Poluentes Químicos da Água/análise , Áreas Alagadas
3.
Environ Sci Pollut Res Int ; 28(1): 982-994, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32829434

RESUMO

The purpose of the present study was to investigate the efficacy of the experimental formulations of the metribuzin (MET) and tribenuron-methyl (TBM) herbicides embedded in the matrix of degradable poly-3-hydroxybutyrate blended with wood flour in field-grown tomato and beet crops infested by weeds. There is a necessity to develop environmentally friendly and effective means to protect plants because of the shortcomings of the free herbicide forms such as the environmentally unsafe spray application of solutions and suspensions of the widespread metribuzin and tribenuron-methyl herbicides, removal from soil during watering events and rains, and transport to natural aquatic environments, where the herbicides accumulate in the trophic chains of biota. Free TBM is also rapidly inactivated in soil and metabolized to nontoxic products in plants. The efficacy of experimental formulations of metribuzin and tribenuron-methyl embedded in the matrix of degradable poly-3-hydroxybutyrate blended with wood flour was tested in field-grown tomato and beet crops infested with weeds. Application of metribuzin resulted in the highest productivity of tomatoes (2.3 kg/m2) and table beet (3.4 kg/m2), improved biometric parameters of tomato fruits and beet roots, and caused reduction in nitrate nitrogen concentrations in them. The mode of herbicide delivery did not affect sugar contents, but application of both metribuzin and tribenuron-methyl induced a 1.7-fold and 1.4-fold, respectively, increase in vitamin C concentrations in tomato fruits and beet roots relative to the vegetables grown on the subplots treated with free herbicides and the intact plants. Embedded herbicides can be used as preemergence herbicides in the field. Fig. a Graphical abstract.


Assuntos
Herbicidas , Sulfonatos de Arila , Herbicidas/análise , Triazinas , Verduras
4.
Sci Total Environ ; 753: 141950, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32906044

RESUMO

2,4-dichlorophenoxyacetic acid (2,4-D), a widely used herbicide, is a small organic chemical pollutant in the environment. To develop a nanobody-based immunoassay for monitoring trace levels of 2,4-D, a step-wise strategy for the generation of nanobodies highly specific against this small chemical was employed. Firstly, we synthesized three novel haptens mimicking 2,4-D and assessed their influence on the sensitivity and specificity of the existing antibody-based assay. Polyclonal antibodies (pAb) from rabbits showed good sensitivity and moderate specificity for 2,4-D, pAb from llama based on selected haptens showed similar performance when compared to those from rabbits. Secondly, nanobodies derived from llama were generated for 2,4-D by an effective procedure, including serum monitoring and one-step library construction. One nanobody, NB3-9, exhibited good sensitivity against 2,4-D (IC50 = 29.2 ng/mL) had better specificity than the rabbit pAb#1518, with no cross-reactivities against the 2,4-D analogs tested. Thirdly, one-step fluorescent enzyme immunoassay (FLEIA) for 2,4-D based on a nanobody-alkaline phosphatase (AP) fusion was developed with IC50 of 1.9 ng/mL and a linear range of 0.4-8.6 ng/mL. Environmental water samples were analyzed by FLEIA and LC-MS/MS for comparison, and the results were consistent between both methods. Therefore, the proposed step-wise strategy from hapten design to nanobody-AP fusion production was successfully conducted, and the resulting nanobody based FLEIA was demonstrated as a convenient tool to monitor 2,4-D residuals in the environment.


Assuntos
Herbicidas , Água , Ácido 2,4-Diclorofenoxiacético , Animais , Cromatografia Líquida , Ensaio de Imunoadsorção Enzimática , Herbicidas/análise , Coelhos , Espectrometria de Massas em Tandem
5.
J Environ Manage ; 280: 111860, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33373816

RESUMO

Herbicide use on boreal transmission line rights-of-way has been relatively limited compared to more temperate regions and therefore challenges exist in estimating and communicating the associated risks. Herbicides directly enter the ecosystem through deposition on vegetation and soils and can be a vector of contamination to browsing herbivores. Triclopyr drift and foliage concentrations were quantified following basal bark (Garlon RTU) and low-volume foliar (Garlon XRT) field treatments to aspen (Populus tremuloides) saplings and willow (Salix bebbiana) shrubs, respectively. Greater drift concentrations localized at the stem base were observed following basal bark treatments. Conversely, concentrations in foliage following the low-volume foliar treatment (DT50 = 5.7 days and DT90 = 34.6 days) were much higher than following basal bark treatment, which also required two days to translocate into the leaves. However, dissipation was rapid from both application methods and triclopyr in foliage was less than 20 µg g-1 a year following application. A risk assessment revealed an acceptable level of risk for acute toxicity to wildlife browsing on contaminated leaves from the residues detected in this study; however, an unacceptable level of risk for chronic toxicity to long-term browsing moose. Site-specific data regarding browsing behaviour on herbicide treated rights-of-ways and species-specific reference values are needed to improve confidence in the tier-two risk assessment. Basal bark application is ideal when stem density is lower and toxic effects for herbivores is of concern and low-volume foliar applications are best suited in areas with higher stem density when off-target herbicide deposition is less acceptable.


Assuntos
Herbicidas , Salix , Ecossistema , Herbicidas/análise , Herbicidas/toxicidade , Solo
6.
Chemosphere ; 262: 128327, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182089

RESUMO

The globally used herbicide glyphosate and its metabolite aminomethylphosphonic acid (AMPA) have not yet been reported to occur in the marine environment, presumably due to a lack of suitable analytical methods. In this study, we developed two new methods for the analysis of glyphosate and AMPA in seawater: a small-scale method, which includes an SPE cleanup step that minimizes salt-matrix effects during LC-MS/MS analysis, and a large-scale method that employs an additional SPE preconcentration step. Different SPE materials were evaluated for their suitability to enrich glyphosate and AMPA from saltwater and a molecularly imprinted polymer was selected. Both methods were validated in ultrapure water and environmental seawater. Achieved limits of detection with the small-scale method were 6 and 8 ng/L for glyphosate and AMPA, while the large-scale method achieved 0.12 and 0.22 ng/L, respectively. The small-scale method was used to analyze environmental samples from the Warnow Estuary in Germany. Glyphosate and AMPA could be successfully detected in the samples, but could not be measured beyond the saline estuary due to dilution and degradation effects. A set of samples from the western Baltic Sea was analyzed with the large-scale method. Glyphosate and AMPA could be detected in all Baltic Sea samples, especially at stations close to estuaries. To the best of our knowledge, this is the first report on the occurrence of glyphosate and AMPA in seawater.


Assuntos
Monitoramento Ambiental/métodos , Glicina/análogos & derivados , Herbicidas/análise , Organofosfonatos/análise , Água do Mar/química , Poluentes Químicos da Água/análise , Cromatografia Líquida/métodos , Estuários , Alemanha , Glicina/análise , Limite de Detecção , Oceanos e Mares , Espectrometria de Massas em Tandem/métodos
7.
Chemosphere ; 262: 127851, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32781333

RESUMO

A monitoring study was carried out in three agriculturally influenced microcatchments in Costa Rica during 2012-2014, for pesticides and water quality parameters. A total of 42 pesticides were analyzed, detecting the following in water samples: two herbicides (oxyfluorfen, diuron), four insecticides (carbofuran, chlorpyrifos, oxamyl, ethion), and two fungicides (thiabendazole, carbendazim); while in sediment samples only the insecticides, chlorpyrifos and cypermethrin were found. Water quality was also assessed by the Canadian Council of Ministers of the Environment Water Quality Index and the National Sanitation Water Quality Index, the first one classified most of the sampling point as marginal and poor quality while the second one classified most of them as good quality, the most affected parameters were nitrate, phosphorous, suspended solids and organic matter content. The results suggest that the water quality in the microcatchments seems to be affected by the nearby agricultural and urban activities in the region.


Assuntos
Monitoramento Ambiental , Praguicidas/análise , Poluentes Químicos da Água/análise , Agricultura , Canadá , Carbamatos , Clorpirifos , Diurona , Herbicidas/análise , Inseticidas/análise , Compostos Organotiofosforados , Rios , Estados Unidos , Qualidade da Água
8.
J Environ Sci (China) ; 100: 131-143, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33279026

RESUMO

The widespread use of pesticides has resulted in detectable residues throughout the environment, sometimes at concentrations well above regulatory limits. Therefore, the development of safe, effective, field-practical, and economically feasible strategies to mitigate the effects of pesticides is warranted. Glyphosate is an organophosphorus herbicide that is degraded to aminomethylphosphonic acid (AMPA), a toxic and persistent metabolite that can accumulate in soil and sediment and translocate to plants. In this study, we investigated the binding efficacy of activated carbon (AC) and calcium montmorillonite (CM) clay to decrease AMPA bioavailability from soil and AMPA translocation to plants. Adsorption isotherms and thermodynamic studies on AC and CM were conducted and showed tight binding (enthalpy values >-20 kJ/mol) for AMPA with high capacities (0.25 mol/kg and 0.38 mol/kg, respectively), based on derivations from the Langmuir model. A hydra assay was utilized to indicate toxicity of AMPA and the inclusion of 1% AC and CM both resulted in 90% protection of the hydra (**p ≤ 0.01). Further studies in glyphosate-contaminated soil showed that AC and CM significantly reduced AMPA bioavailability by 53% and 44%, respectively. Results in genetically modified (GM) corn showed a conversion of glyphosate to AMPA in roots and sprouts over a 10-day exposure duration. Inclusion of AC and CM reduced AMPA residues in roots and sprouts by 47%-61%. These studies collectively indicate that AC and CM are effective sorbents for AMPA and could be used to reduce AMPA bioavailability from soil and AMPA residues in GM corn plants.


Assuntos
Herbicidas , Poluentes do Solo , Bentonita , Disponibilidade Biológica , Cálcio , Carvão Vegetal , Argila , Herbicidas/análise , Organofosfonatos , Solo , Poluentes do Solo/análise , Zea mays/genética , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico
9.
Chemosphere ; 264(Pt 1): 128494, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33022507

RESUMO

The understanding of the interaction between soil physicochemical attributes and herbicide behavior is fundamental for optimizing the efficient use of PRE-emergence herbicides in a more sustainable approach. However, it is still a poorly studied area within precision agriculture. Thus, the objective of this research was to evaluate the correlation of soil physicochemical attributes with the sorption and desorption processes of hexazinone and tebuthiuron to support application maps considering the field level variability. Soil samples from an agricultural area had their physicochemical attributes analyzed and were submitted to sorption and desorption studies of 14C-tebuthiuron and 14C-hexazinone using the batch equilibrium method. The values of sorption and desorption apparent coefficients (Kd), sorption and desorption percentage and bioavailability were correlated with soil attributes by Pearson's correlation. The Kd values of tebuthiuron and hexazinone sorption ranged from 1.2 to 2.9 mL g-1 and 0.4-0.6 mL g-1, respectively. For desorption of tebuthiuron and hexazinone, Kd values ranged from 3.4 to 4.4 mL g-1 and 2.6-3.0 mL g-1, respectively. A positive correlation among clay content, soil organic matter (OM), and tebuthiuron and hexazinone sorption Kd values were found. Both herbicides had variable retention according to geographic position in the area. The recommendation of application of PRE herbicides, such as tebuthiuron and hexazinone, observing the physicochemical attributes of the soil is an alternative to increase efficiency in weed control and decrease the risk of environmental contamination.


Assuntos
Herbicidas , Poluentes do Solo , Adsorção , Herbicidas/análise , Compostos de Metilureia , Solo , Poluentes do Solo/análise , Triazinas
10.
Chemosphere ; 264(Pt 2): 128514, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33045503

RESUMO

Residual injury of atrazine to the succeeding crops has been frequently reported. It is necessary to find a solution for the detoxification of atrazine contaminated soil. A high-efficient bacterial strain Arthrobacter sp. C2 for atrazine degradation was isolated in this study. The genomic information of the isolate C2, and its degradation characteristics and potential application in detoxification of atrazine contaminated soil were investigated. The results indicated that the isolate C2 genome contained 4,305,216 bp nucleotides, three plasmids, and 4705 coding genes. The degradation rates of atrazine at levels of 1, 10, 100 mg/L by the isolate C2 were 0.34, 1.94, 18.64 mg/L/d, respectively. The optimum temperature and pH for the isolate C2 to degrade atrazine were 30 °C and 7.0-9.0. Based on the metabolites detected by UPLC-TOF-MS/MS and genome annotation of the isolate C2, a common metabolic pathway of atrazine was proposed as that atrazine is firstly dechlorinated into hydroxyatrazine, and subsequently to N-isopropylammelide via dealkylation, and ultimately deaminated to cyanuric acid. Introduction of the isolate C2 into soil can enhance degradation of atrazine and thus eliminate the toxic effect of this herbicide on wheat growth. Our results indicate that the strain C2 could be a potential bioresource for bioremediation of atrazine contaminated soil.


Assuntos
Arthrobacter , Atrazina , Herbicidas , Poluentes do Solo , Arthrobacter/genética , Atrazina/análise , Atrazina/toxicidade , Biodegradação Ambiental , Herbicidas/análise , Herbicidas/toxicidade , Microbiologia do Solo , Poluentes do Solo/análise , Espectrometria de Massas em Tandem
11.
Chemosphere ; 263: 127638, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32828049

RESUMO

Invasive, nuisance aquatic species such as Eurasian watermilfoil (Myriophyllum spicatum) are rapidly spreading across the United States. One common active ingredient used to control this invasive species is 2,4-Dichlorophenoxyacetic acid (2,4-D). Application of 2,4-D to aquatic environments typically occurs while many freshwater fish are spawning and due to 2,4-D stability in aquatic environments, many non-target species experience prolonged exposure throughout embryogenesis and larval development. The impacts of 2,4-D exposure on phylogenetically distant fish species is poorly understood. Herein, we investigated the impacts of the 2,4-D commercial herbicide DMA4®IVM on nine freshwater fish species from six different families (four orders) at different points during ontogeny. Each species was exposed to ecologically relevant concentrations of a commercial 2,4-D herbicide (0.05, 0.50, and 2.00 ppm or mg/L 2,4-D a. e.), and effects on morphology, survival, and growth were evaluated. Our results demonstrate that exposure of embryonic and larval fish to ecologically relevant concentrations of a commercial 2,4-D herbicide reduced survival in early developmental stages of six freshwater species that spanned five phylogenetic families and three phylogenetic orders; however, sensitivity to 2,4-D exposure did not show correlation with phylogenetic proximity. Altogether, our results indicate that the use of 2,4-D herbicides in aquatic ecosystems at current recommended concentrations (≤2 ppm whole-lake treatment) could present risk to multiple freshwater fish species survival during early development.


Assuntos
Herbicidas , Poluentes Químicos da Água , Ácido 2,4-Diclorofenoxiacético/toxicidade , Animais , Ecossistema , Água Doce , Herbicidas/análise , Herbicidas/toxicidade , Humanos , Filogenia , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
12.
Ecotoxicol Environ Saf ; 207: 111222, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32890950

RESUMO

Sulfometuron-methyl is a broad-spectrum herbicide, used throughout Brazil; however, its environmental impacts in biochar (BC) amended soils is not fully understood. Biochar is known to enhance soil quality but can also have undesired effects such as altering the bioavailability and behavior of herbicides. Microbial communities can degrade herbicides such as sulfometuron-methyl in soils; however, they are known to be affected by BC. Therefore, it is important to understand the tripartite interaction between these factors. This research aimed to evaluate the sorption-desorption and biodegradation of sulfometuron-methyl in Amazonian soils amended with BC, and to assess the effects of the interactions between BC and sulfometuron-methyl on soil bacterial communities. Soil samples were collected from field plots amended with BC at three doses (0, 40 and 80 t ha-1) applied ten years ago. The herbicide sorption and desorption were evaluated using a batch equilibrium method. Mineralization and biodegradation studies were conducted in microcosms incubated with 14C-sulfometuron-methyl for 80 days. Systematic soil sampling, followed by DNA extraction, quantification (qPCR) and 16S rRNA amplicon sequencing were performed. The presence of BC increased the sorption of the herbicide to the soil by 11% (BC40) and 16% (BC80) compared to unamended soil. The presence of BC also affected the degradation of 14C-sulfometuron-methyl, reducing the mineralization rate and increasing the degradation half-life times (DT50) from 36.67 days in unamended soil to 52.11 and 55.45 days in BC40 and BC80 soils, respectively. The herbicide application altered the bacterial communities, affecting abundance and richness, and changing the taxonomic diversity (i.e., some taxa were promoted and other inhibited). A tripartite interaction was found between BC, the herbicide and soil bacterial communities, suggesting that it is important to consider the environmental impact of soil applied herbicides in biochar amended soils.


Assuntos
Biodegradação Ambiental , Herbicidas/análise , Poluentes do Solo/análise , Compostos de Sulfonilureia/análise , Adsorção , Bactérias/metabolismo , Disponibilidade Biológica , Brasil , Carvão Vegetal , RNA Ribossômico 16S/metabolismo , Solo
13.
Sci Total Environ ; 750: 141507, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32841807

RESUMO

Studies on the occurrence of emerging pesticides in surface and drinking water in Vietnam are limited. In this study, lake water (n = 7), river water (n = 1), tap water (n = 46), and bottled water (n = 3) collected from Hanoi and other four provinces in northern Vietnam were analyzed for selected pesticides (including insecticides such as neonicotinoids, fipronil, and chlorpyrifos; fungicide carbendazim; herbicides such as atrazine, terbuthylazine, simazine, 2,4-dichlorophenoxyacetic acid, 2-methyl-4-chlorophenoxyacetic acid, and bentazon) and some of their degradates by liquid chromatography-tandem mass spectrometry. Carbendazim (median: 86.7 ng/L) and triazines (49.3 ng/L) were the major pesticides found in lake water samples, followed by neonicotinoids and their degradation products (15.1 ng/L), chlorpyrifos and its degradate (13.4 ng/L), fipronil and its degradates (3.76 ng/L), chlorophenoxy acid herbicides (2.10 ng/L), and bentazon (0.62 ng/L). Triazines (164 ng/L) were the major pesticides in river water. Higher concentrations (median: 39.3 ng/L; range: 1.20-127) of selected pesticides were found in tap water from Hanoi than those from four other provinces studied (5.49 ng/L; 4.73-66.8 ng/L). Bottled water samples collected from Hanoi contained lower concentrations of pesticide residues (median: 3.54 ng/L, range: 2.18-8.09) than those of tap water samples. The calculated risks from pesticide exposure through ingestion of tap water by the general populations were low. However, fipronil concentrations in lake water exceeded the benchmark value recommended for freshwater in the United States or the Netherlands. Degradation of acetamiprid into desmethyl-acetamiprid was found in lake water.


Assuntos
Clorpirifos , Água Potável , Herbicidas , Praguicidas , Poluentes Químicos da Água , Benzimidazóis , Benzotiadiazinas , Carbamatos , Água Potável/análise , Herbicidas/análise , Neonicotinoides , Países Baixos , Praguicidas/análise , Pirazóis , Vietnã , Poluentes Químicos da Água/análise
14.
Food Chem ; 334: 127345, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32712485

RESUMO

The development of a novel molecularly imprinted solid-phase extraction (MISPE) method for simultaneous preconcentration of imazapyr (IMP), imazapic (IMZ) and imazethapyr (IMT) with determination by HPLC-PAD (High performance liquid chromatography - photodiode-array detector) is proposed. The polymer synthesis was performed using imazethapyr as template molecule and 1-vinylimidazole as functional monomer. The method is based on preconcentration of 100.0 mL of sample through 200.0 mg of molecularly imprinted poly(vinylimidazole-TRIM) (MIP-1VN) at pH 4.0, followed by elution with 2.0 mL of MeOH:CH2Cl2:HAc (34:62:4, v/v). The range of analytical curve (0.29-200.0, 0.21-200.0 and 0.15-200.0 µg L-1), limits of detection (0.09, 0.06 and 0.04 µg L-1) and preconcentration factors (92, 96 and 98) determined for the herbicides, IMP, IMZ and IMT, respectively, were greatly superior when compared with those ones obtained with commercial adsorbents. The analytical method was successfully applied to spiked surface water and rice samples with good results of recovery values (86-107%).


Assuntos
Herbicidas/análise , Impressão Molecular/métodos , Oryza/química , Extração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Alimentos/análise , Imidazóis/análise , Imidazóis/síntese química , Imidazóis/química , Limite de Detecção , Niacina/análogos & derivados , Niacina/análise , Ácidos Nicotínicos/análise , Ácidos Nicotínicos/química , Polivinil/síntese química , Polivinil/química , Sementes/química , Extração em Fase Sólida/instrumentação
15.
Water Res ; 188: 116573, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33152590

RESUMO

When an invasive wetland grass degrades a Ramsar wetland and Important Bird Area, decisive management action is called for. To limit the extent and spread of European Phragmites australis, the Ontario government began the first, large-scale application of glyphosate (Roundup CustomⓇ) over standing water to control an invasive species in Canadian history. Between 2016 and 2018, over 1000 ha of marsh were treated. To assess the concentration, movement and longevity of this herbicide in treated marshes, we measured the concentration of glyphosate, its primary breakdown product aminomethylphosphonic acid (AMPA), and the alcohol ethoxylate-based adjuvant AquasurfⓇ in water and sediments in areas of the highest exposure and up to 150 m into adjacent bays. The maximum observed concentration of glyphosate in water was 0.320 mg/L, occurring within 24 hr of application. The maximum glyphosate concentration in sediment was 0.250 mg/kg, occurring within about 30 days of application. AMPA was detectable in water and sediment, indicating microbial breakdown of glyphosate in the marsh, but at low concentrations (maxwater = 0.025 mg/L, maxsed = 0.012 mg/kg). The maximum distance from the point of application that glyphosate was detected in the water was 100 m, while AMPA was detectable only at the edge of where glyphosate was applied (0 m). Concentrations in water returned to pre-treatment levels (0.005 mg/kg) for over one year but less than two years. Concentrations of alcohol ethoxylates were variable in space and time, following a pattern that could not be attributed to AquasurfⓇ use. The direct, over-water application of Roundup CustomⓇ with AquasurfⓇ to control invasive P. australis did not reach concentrations deemed to pose toxicological concern to aquatic biota by the Canadian Council of Ministers of the Environment.


Assuntos
Herbicidas , Poluentes Químicos da Água , Monitoramento Ambiental , Glicina/análogos & derivados , Herbicidas/análise , Ontário , Organofosfonatos , Plantas , Água , Poluentes Químicos da Água/análise
16.
Ecotoxicol Environ Saf ; 207: 111285, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32931964

RESUMO

The present work scrutinized the voltammetric analysis of hazardous herbicide aclonifen (ACF) in actual soil and river water samples utilizing the electrochemical method. The electrochemical sensing device was fabricated for the determination of ACF using gadolinium niobate (GdNbO4) nanoparticles modified glassy carbon electrode (GCE). The novel GdNbO4 sensing material was prepared via a simple co-precipitation method. Several characterization techniques (TEM, EDS, XRD, XPS, and BET) were utilized to analyze the structural features of the GdNbO4. The enhanced electrochemical behavior of GdNbO4 modified GCE towards ACF was observed compared to bare GCE. The cyclic voltammetry response revealed that the prepared sensor shows the lower negative potential with a dramatic increase in the peak current of ACF compared to bare GCE. In the differential pulse voltammetry, the limit of detection (1.15 nM) and sensitivity (23 µA µM-1 cm-2) of the ACF on the GdNbO4 modified GCE was comparatively superior to the formerly proposed ACF based sensor. This sensor reveals good selectivity, repeatability, reproducibility, and long-term stability. The reliability of the sensor exhibits satisfactory recovery results for ACF detection in river water and soil samples.


Assuntos
Compostos de Anilina/análise , Técnicas Eletroquímicas/métodos , Monitoramento Ambiental/métodos , Herbicidas/análise , Nanopartículas/química , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Carbono , Catálise , Eletrodos , Limite de Detecção , Reprodutibilidade dos Testes , Rios/química , Solo/química , Propriedades de Superfície
17.
Pest Manag Sci ; 77(1): 253-263, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32687689

RESUMO

BACKGROUND: Residual herbicides are an important component in many weed control strategies. Their herbicidal activity depends on their fate in soil, with respect to the required concentration for weed control in space and time. In this study, the effect of weather conditions on sulfosulfuron fate in soil, following pre-planting incorporation, and the predicted control efficacy of Egyptian broomrape in tomato, were analyzed for two sites using simulations in Hydrus-1D modeling software. Simulated concentration was compared to measured data from field experiments. RESULTS: Model evaluation against measured data from two fields, with weakly alkaline clay soils, showed high correlations between simulated and measured sulfosulfuron concentrations (r = 0.98 and 0.89). The ratio of measured to simulated concentration was relatively low (1.03) at the top 10-cm layer, in which the mean measured concentration was high (29.6 ng g-1 ). This ratio was higher (12.5) at the 30-60 cm depth, in which the mean measured concentration was lower (0.3 ng g-1 ). Simulations of sulfosulfuron fate in each site, using weather data from the years 2009 to 2019, revealed substantial variations in transport patterns. Thirty days after treatment, 16 out of the 22 years simulated for the two sites (11 at each site) resulted in concentrations lower than the critical value for Egyptian broomrape control throughout the soil profile. The data indicates that variation in sulfosulfuron fate is mainly due to differences in the cumulative precipitation. According to simulation results, cumulative precipitation above 20 or 10 mm during the first 10 or 20 days after treatment, respectively, is expected to reduce the efficiency of broomrape control. CONCLUSION: Considering weather effects when planning herbicide application could optimize herbicide use efficiency. A decision-support tool is presented, whose factors are the time gap and precipitation amount between sulfosulfuron application and tomato planting.


Assuntos
Herbicidas , Poluentes do Solo , Herbicidas/análise , Pirimidinas/análise , Solo , Poluentes do Solo/análise , Sulfonamidas , Tempo (Meteorologia)
18.
Sci Total Environ ; 755(Pt 1): 142827, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33097257

RESUMO

Freshwater occurrences of the selective acid herbicide 2-methyl-4-chloro-phenoxyacetic acid (MCPA) are an ongoing regulatory and financial issue for water utility industries as the number and magnitude of detections increase, particularly in surface water catchments. Assessments for mitigating pesticide pollution in catchments used as drinking water sources require a combination of catchment-based and water treatment solutions, but approaches are limited by a lack of empirical data. In this study, an enhanced spatial (11 locations) and temporal (7-hourly to daily sampling) monitoring approach was employed to address these issues in an exemplar surface water source catchment (384 km2). The spatial sampling revealed that MCPA was widespread, with occurrences above the 0.1 µg L-1 threshold for a single pesticide being highly positively correlated to sub-catchments with higher proportions of 'Improved Grassland' land use (r = 0.84). These data provide a strong foundation for targeting catchment-based mitigation solutions and also add to the debate on the ecosystems services provided by such catchments. Additionally, of the 999 temporal samples taken over 12 months from the catchment outlet, 25% were above the drinking water threshold of 0.1 µg L-1. This prevalence of high concentrations presents costly problems for source water treatment. Using these data, abstraction shutdowns were simulated for five scenarios using hydrometeorological data to explore the potential to avoid intake of high MCPA concentrations. The scenarios stopped abstraction for 4.2-9.3% of the April-October period and reduced intake of water containing over 0.1 µg L-1 of MCPA by 16-31%. This represents an important development for real-time proxy assessments for water abstraction in the absence of more direct pesticide monitoring data.


Assuntos
Ácido 2-Metil-4-clorofenoxiacético , Água Potável , Herbicidas , Poluentes Químicos da Água , Acetatos , Ecossistema , Monitoramento Ambiental , Herbicidas/análise , Poluentes Químicos da Água/análise , Poluição da Água
19.
Chemosphere ; 263: 127910, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297009

RESUMO

The important effect of soil wetting and drying cycle (WDC) on soil structure, and the consequent effect on pollutant fate is underexplored. We thoroughly investigated the changes in soil structure and in leaching of Alion (indaziflam) and Express (tribenuron methyl), pre and post WDC, from two clayey soils and two loamy soils under different land uses (uncultivated, field crops, and orchards). Soil stability was quantified by an aggregate durability index we recently developed. WDC did not affect the stability of the sandy-loam soils, as expected. However, for the sandy-clay-loam with high CaCO3 content aggregation was observed. For the clayey soils with similar CaCO3, aggregation and disaggregation were obtained, for a soil with relatively low and high SOM, respectively. The stability trends are reflected by the ratio between the contents of inorganic carbon and soil organic matter (SOM), CaCO3/SOM, normalized to the clay content. Aggregation was explained by CaCO3 cementation, while disaggregation was attributed to high clay content and to alterations in SOM conformation post WDC. These opposite trends, obtained for the two clayey soils, were confirmed by analyzing changes in soil packing employing X-ray tomography (micro-CT). Our results clearly demonstrated that soil aggregation and disaggregation, induced by a WDC, suppresses and enhances herbicide mobility, respectively. However, the effect of WDC on herbicide leaching was not noticeable for Alion upon its high adsorption to a clayey soil, indicating that herbicide physical-chemical properties may dominate. Finally, WDC induces micron-scale changes in aggregate structure, which have a notable effect on pollutant mobility and fate in the environment.


Assuntos
Herbicidas , Praguicidas , Poluentes do Solo , Adsorção , Herbicidas/análise , Solo , Poluentes do Solo/análise
20.
Chemosphere ; 263: 128061, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297067

RESUMO

The present study aimed to assess the ecological risk of 30 current-use agricultural pesticides and biocides in the soil, sediments and aquatic organisms of a mixed land-use basin located in the Depressed Pampas Region of Argentina. Risk Quotients (RQs) were used to evaluate the chronic risk in soil and aquatic organisms, while Toxic Units (TUs) were used to assess the acute risk in sediment-dwelling organisms and aquatic biota. Acetochlor, hydroxy-atrazine, glyphosate, AMPA, metolachlor, imidacloprid and tebuconazole were the only pesticide residues detected (>30%) and quantified in all the matrices evaluated. Glyphosate and AMPA showed the highest concentrations, being their mean and maximum levels 27.90-176.00 µg kg-1 and 270-712.50 µg kg-1 in soils, 8.28-32.0 µg kg-1 and 6.85-17.50 µg kg-1 in sediments, and 1.88-4.36 µg L-1 and 0.66-1.03 µg L-1 in surface water. The RQs in soils showed high chronic risk, mainly due to AMPA and imidacloprid. The TUs in sediments showed acute risk in dwelling organisms, mainly due to glyphosate and imidacloprid. RQs assessment showed a range of chronic risk levels according to the site/sampling event, with higher contribution of atrazine and its metabolites, and acetochlor, whereas TUs assessment showed no acute risk in aquatic biota. In contrast to Europe, in Argentina, there are no restrictions regarding the use of atrazine, acetochlor, imidacloprid and glyphosate to protect aquatic life. Thus, it is recommended that the current Argentine pesticide regulations should be modified to prevent ecological risk and protect ecosystems.


Assuntos
Desinfetantes , Herbicidas , Praguicidas , Poluentes Químicos da Água , Argentina , Ecossistema , Monitoramento Ambiental , Europa (Continente) , Herbicidas/análise , Praguicidas/análise , Medição de Risco , Solo , Água , Poluentes Químicos da Água/análise
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