Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20.454
Filtrar
1.
J Environ Manage ; 270: 110690, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721282

RESUMO

Constructed wetlands (CWs) are likely to reduce pesticide levels reaching surface water. However, the distribution of the water flow path between the main channel and isolated areas may influence global pesticide mitigation. Little information is known about the influence of water pathways on pesticide mitigation. Thus, we performed tracer experiments at low and high flow rates (0.5 L/s and 4-7 L/s) in a pond CW and ditch CW to determine the localization of various hydraulic zones and to understand their implication on pesticide mitigation. The hydraulic performance reflecting the fraction of water transported from inlet to outlet passing through the whole of CW, was greater for the pond CW than for the ditch CW regardless of the flow rate, and greater at mean flow rates (MF) than at low flow rates (LF) due to a lower proportion of isolated areas at a MF (11%-68%) than at LF (38%-89%). Dispersion governed the water transport inside the isolated areas and the water convection inside the main channel. Consequently, dissolved pesticide concentrations are heterogeneously distributed in the CWs, i.e., in the main channel and isolated area, for both flow rates. However, one month after a no-flow period, this heterogeneity disappears, and dissolved pesticide concentrations become similar in the water of the whole CW due to dispersion. Furthermore, sedimentation and storage in sediments were greater in the isolated area than in the main channel, which is possibly due to a lower speed flow rate and a higher hydraulic residence time (HRT) in the isolated area than in the main channel. Thus, isolated areas act as effective's zones to mitigate pesticides from dissolved and particulate phases inside the CW during a complete drainage season (i.e., succession of high/low/no-flow periods).


Assuntos
Praguicidas/análise , Poluentes Químicos da Água/análise , Hidrodinâmica , Eliminação de Resíduos Líquidos , Água , Áreas Alagadas
2.
GM Crops Food ; 11(4): 215-241, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32706316

RESUMO

This paper updates previous assessments of the environmental impacts associated with using crop biotechnology (specifically genetically modified crops) in global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops since their first widespread commercial use 22 years ago. The adoption of GM insect resistant and herbicide tolerant technology has reduced pesticide spraying by 775.4 million kg (8.3%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator, the Environmental Impact Quotient (EIQ)) by 18.5%. The technology has also facilitated important cuts in fuel use and tillage changes, resulting in a significant reduction in the release of greenhouse gas emissions from the GM cropping area. In 2018, this was equivalent to removing 15.27 million cars from the roads.


Assuntos
Produtos Agrícolas/genética , Praguicidas , Agricultura , Animais , Carbono , Meio Ambiente , Efeito Estufa , Plantas Geneticamente Modificadas
3.
Pestic Biochem Physiol ; 168: 104633, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32711767

RESUMO

Some quinuclidine benzamide compounds have been found to modulate nicotinic acetylcholine receptors in both mammals and insects. In particular, the quaternarization of 3-amino quinuclidine benzamide derivatives with dichloromethane gave charged N-chloromethylated quinuclidine compounds, disclosing an antagonist profile on homomeric α7 nAChRs. Here, we synthesized and studied the toxicological effect of LMA10233, a quinuclidine-borane complex analogue, the LMA10233, on the pea aphid Acyrthosiphon pisum and found that LMA10233 only exhibit proper toxicity on A. pisum larvae when applied in concentrations of over 10 µg/ml. We assessed the ability of LMA10233 to enhance the toxicity of different insecticides. When a sublethal concentration of LMA10233 was combined with the LC10 of each compound, we found a strong increase in toxicity at 24 h and 48 h of exposure for clothianidin, fipronil and chlorpyrifos, and only at 24 h for imidacloprid, acetamiprid and deltamethrin. However, when the pesticide was used at the LC50, only acetamiprid showed a synergistic effect with LMA10233. When the concentration of LMA10233 was decreased, we found that up to 80-90% of mortality was obtained due to the synergism between acetamiprid and LMA10233. No similar effect was observed with other insecticides. We conclude that such quinuclidine-borane complex compounds could increase the toxic effect of insecticides at low concentrations.


Assuntos
Boranos , Inseticidas , Praguicidas , Animais , Benzamidas , Neonicotinoides , Nitrocompostos , Quinuclidinas
4.
Environ Monit Assess ; 192(8): 546, 2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-32719898

RESUMO

Seven pesticides, profenofos, metalaxyl, λ-cyhalothrin, 4,4'-DDT, 4,4'-DDE, and α- and ß-endosulfan, were determined in vegetables (tomato, onion) from 20 locations and surface waters from 12 locations in the Central Rift Valley (CRV) of Ethiopia. Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) and solid phase extraction (SPE) methods were used for the vegetables and water, respectively. In 2.5% of the tomato samples, profenofos was detected above European maximum residue limits (MRLs), in 12.5% of the samples metalaxyl, and in 2.5% α- and ß-endosulfan. In 5% of the onion samples, profenofos was detected above European MRLs, in 7.5% of the onion samples metalaxyl, and in 5% λ-cyhalothrin. In surface water, profenofos was detected at the highest concentration of 2300 µg/L in the Bulbula River, 890 µg/L near the agricultural land north of Lake Ziway (ANLZ-1), 1700 µg/L in the floriculture effluent (FE-1), and 900 µg/L in tap water at the Batu Drinking Water (BDW) supply. These results show that the levels of pesticides are in several cases substantially elevated, and emphasize the need of regular pesticide monitoring programs for surface waters and vegetables in the Ethiopian CRV.


Assuntos
Resíduos de Praguicidas/análise , Praguicidas/análise , Monitoramento Ambiental , Etiópia , Contaminação de Alimentos/análise , Verduras
5.
Environ Monit Assess ; 192(7): 475, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32613317

RESUMO

The Western Sandpiper, Calidris mauri, is one of the most abundant migratory shorebirds in the Western Hemisphere. Both Bahia Santa Maria (SM) and Ensenada Pabellones (EP) in Sinaloa, Mexico, are critical wintering sites for this species. We described the presence and concentration of 16 organochlorine pesticides (OCPs) in Western Sandpiper muscle and liver tissues collected from SM and EP during the wintering (December-January) and premigration (March-April) periods of 2010 and 2011, respectively. The individual OCP concentrations varied from 0.003 to 0.127 µg/g dry weight (dw) and were lower than the established thresholds for either acute or chronic effects. Western Sandpipers in SM-Premigration had the highest frequency of OCPs (39.3%), followed by EP-Winter (32.1%) and SM-Winter (28.5%). The frequency of occurrence of all OCPs in the liver presented differences between sites during the wintering period as well as between the wintering and premigration periods in SM. As the primary organ responsible for pollutant detoxification, the liver may bioaccumulate these compounds. No clear trends were observed in muscle tissues or among age-sex groups. Our results showed evidence of OCP bioaccumulation in the Western Sandpiper during the wintering period, which may be related to hyperphagia during the premigration period and to the differential intake of OCP types and quantities between sites due to differences in their availability. However, these conclusions are based on relatively low sample sizes for some groups and require further study with non-pooled samples.


Assuntos
Hidrocarbonetos Clorados , Praguicidas , Animais , Bioacumulação , Monitoramento Ambiental , México , Estações do Ano
6.
J Environ Sci (China) ; 95: 240-247, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32653186

RESUMO

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are typical persistent organic pollutants (POPs), which have high toxicity, bioaccumulation and long-distance transfer capability. Daily variation, sources of PCBs and OCPs in PM2.5 are rarely explored in polluted rural area. Here, the sources and health risks of the PCBs and OCPs were evaluated for 48 PM2.5 samples collected in winter 2017 in Wangdu, a heavy polluted rural area in the North China Plain. The average diurnal and nocturnal concentrations of Σ18PCBs and Σ15OCPs were 1.74-24.37 and 1.77-100.49, 11.67-408.81 and 16.89-865.60 pg/m3, respectively. Hexa-CBs and penta-CBs accounted for higher proportions (29.0% and 33.6%) of clean and polluted samples, respectively. Hexachlorobenzene (HCB) was the dominant contributor to OCPs with an average concentration of 116.17 pg/m3. Hexachlorocyclohexane (ΣHCHs) and dichlorodiphenyltrichloroethane (ΣDDTs) were the other two main classes in OCPs with the average concentrations of 4.33 and 15.89 pg/m3, respectively. ß-HCH and p,p'-DDE were the main degradation products of HCHs and DDTs, respectively. The principal component analysis and characteristic ratio method indicated both waste incineration and industrial activities were the main sources of PCBs, contributing 76.8% and 12.7%, respectively. The loadings of OCPs were attributed to their application characteristics and the characteristic ratio method reflected a current or past use of OCPs. Health risk assessment showed that the respiratory exposure quantity of doxin-like PCBs (DL-PCBs) and the lifetime cancer risk from airborne OCPs exposure was negligible, while the other exposure modes may pose a risk to human bodies.


Assuntos
Hidrocarbonetos Clorados/análise , Praguicidas/análise , Bifenilos Policlorados/análise , China , Monitoramento Ambiental , Humanos , Material Particulado
7.
Pestic Biochem Physiol ; 167: 104599, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32527443

RESUMO

As an ATP-dependent DNA helicase, RecG can repair DNA replication forks in many organisms. However, knowledge of recG in Bacillus thuringiensis (Bt) is limited. In our previous study, recG was found damaged in Bt LLP29-M19, which was more resistant to ultraviolet light (UV) after exposing Bt LLP29 to UV for 19 generations. To further understand the function of recG in the mechanism of Bt UV resistance, recG was knocked out and recovered with homologous recombination technology in Bt LLP29. Comparing the resistance of the different mutants to UVB, Bt ∆recG-LLP29 lacking recG was found more sensitive to UVB, hydroxyurea (HU) and H2O2 than LLP29 and the complementation strain. To compare the expression level of recG in the Bt strains under different UV treatments, Quantitative Real-time PCR (RT-qPCR) of recG was performed in the tested Bt strains, which showed that the expression level of recG in Bt ∆recG-LLP29 was substantially lower than that in the original strain and complementation strain. Interestingly, when exposed to UV for 20 min, RecG expression in both Bt LLP29 and Bt recG-R was the highest. The unwinding activity of recG in Bt LLP29 and the complementation strain were also found higher than that of the recG knockout strain, Bt ∆recG-LLP29. These results demonstrate that recG is involved with the resistance of Bt to UV. These findings not only enhance the understanding of the Bt UV resistance mechanism, but also provide an important theoretical basis for the application of Bt.


Assuntos
Bacillus thuringiensis , Praguicidas , Proteínas de Bactérias , Peróxido de Hidrogênio , Raios Ultravioleta
8.
Chemosphere ; 257: 127165, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32480088

RESUMO

Phytoplankton and bacterioplankton are the key components of the organic matter cycle in aquatic ecosystems, and their interactions can impact the transfer of carbon and ecosystem functioning. The aim of this work was to assess the consequences of chemical contamination on the coupling between phytoplankton and bacterioplankton in two contrasting marine coastal ecosystems: lagoon waters and offshore waters. Bacterial carbon demand was sustained by primary carbon production in the offshore situation, suggesting a tight coupling between both compartments. In contrast, in lagoon waters, due to a higher nutrient and organic matter availability, bacteria could rely on allochthonous carbon sources to sustain their carbon requirements, decreasing so the coupling between both compartments. Exposure to chemical contaminants, pesticides and metal trace elements, resulted in a significant inhibition of the metabolic activities (primary production and bacterial carbon demand) involved in the carbon cycle, especially in offshore waters during spring and fall, inducing a significant decrease of the coupling between primary producers and heterotrophs. This coupling loss was even more evident upon sediment resuspension for both ecosystems due to the important release of nutrients and organic matter. Resulting enrichment alleviated the toxic effects of contaminants as indicated by the stimulation of phytoplankton biomass and carbon production, and modified the composition of the phytoplankton community, impacting so the interactions between phytoplankton and bacterioplankton.


Assuntos
Fitoplâncton/fisiologia , Poluentes Químicos da Água/toxicidade , Bactérias/metabolismo , Biomassa , Carbono/metabolismo , Ecossistema , Praguicidas/metabolismo , Estações do Ano , Água do Mar/química , Oligoelementos/metabolismo
9.
Chemosphere ; 257: 127095, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32512326

RESUMO

In recent years, the presence of micropollutants in drinking water has become an issue of growing global concern. Due to their low concentrations, monitoring databases are usually rich in censored data (e.g. samples with concentrations reported below the limit of quantification, LOQ) which are typically eliminated or replaced with a value arbitrarily chosen between 0 and LOQ. These conventional methods have some limitations and can lead to erroneous conclusions on: presence of micropollutants in the source water, treatment efficiencies, produced water quality and associated human health risk. In this work, an advanced approach, based on Maximum Likelihood Estimation method for left-censored data (MLELC), was applied on monitoring data of 19 contaminants (metals, volatile organic compounds, pesticides and perfluorinated compounds) in 5362 groundwater (GW) and 12,344 drinking water (DW) samples, collected from 2012 to 2017 in 28 drinking water treatment plants in an urbanized area. This study demonstrates the benefits of MLELC method, especially for high percentages of censored data. Data are used to build statistical distributions which can be effectively used for several applications, such as the time trend evaluation of GW micropollutant concentrations and the estimation of treatment removal efficiency, highlighting the adequacy or the need for an upgrade. Moreover, the MLELC method has been applied to assess the human health risk associated with micropollutants, indicating the high discrepancy in the estimations obtained with conventional methods, whose results do not follow precautionary or sustainability criteria.


Assuntos
Monitoramento Ambiental , Poluentes Químicos da Água/análise , Água Potável , Água Subterrânea , Humanos , Praguicidas/análise , Compostos Orgânicos Voláteis , Água , Poluição Química da Água , Purificação da Água , Qualidade da Água
10.
Environ Sci Pollut Res Int ; 27(24): 29867-29899, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32500500

RESUMO

We present a synthetic review and expert consultation that assesses the actual risks posed by arthropod pests in four major crops, identifies targets for integrated pest management (IPM) in terms of cultivated land needing pest control and gauges the implementation "readiness" of non-chemical alternatives. Our assessment focuses on the world's primary target pests for neonicotinoid-based management: western corn rootworm (WCR, Diabrotica virgifera virgifera) in maize; wireworms (Agriotes spp.) in maize and winter wheat; bird cherry-oat aphid (Rhopalosiphum padi) in winter wheat; brown planthopper (BPH, Nilaparvata lugens) in rice; cotton aphid (Aphis gossypii) and silver-leaf whitefly (SLW, Bemisia tabaci) in cotton. First, we queried scientific literature databases and consulted experts from different countries in Europe, North America, and Asia about available IPM tools for each crop-pest system. Next, using an online survey, we quantitatively assessed the economic relevance of target pests by compiling country-level records of crop damage, yield impacts, extent of insecticide usage, and "readiness" status of various pest management alternatives (i.e., research, plot-scale validation, grower-uptake). Biological control received considerable scientific attention, while agronomic strategies (e.g., crop rotation), insurance schemes, decision support systems (DSS), and innovative pesticide application modes were listed as key alternatives. Our study identifies opportunities to advance applied research, IPM technology validation, and grower education to halt or drastically reduce our over-reliance on systemic insecticides globally.


Assuntos
Inseticidas , Praguicidas , Animais , Ásia , Europa (Continente) , Neonicotinoides , América do Norte
11.
Sci Total Environ ; 735: 138807, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32474246

RESUMO

Freshwater communities are threatened worldwide, with pesticides being one of the main stressors for vulnerable invertebrates. Whereas the effects of pesticides on communities can be quantified by trait-based bioindicators such as SPEARpesticides, single species' responses remain largely unknown. We used the bioindicator SPEARpesticides to predict the toxic pressure from pesticides in 6942 macroinvertebrate samples from 4147 sites during the period 2004 to 2013, obtained by environmental authorities in Germany, and classified all samples according to their magnitude of pesticide pressure. Along this gradient of pesticide pressure, we quantified the occurrence of 139 macroinvertebrate species. We identified 71 species characterized by decreasing occurrence with increasing pesticide pressure. These 'decreasing species', mainly insects, occurred at a frequency of 19.7% at sites with reference conditions and decreased to 1.7% at sites with the highest pesticide pressure. We further determined 55 'nonspecific species' with no strong response as well as 13 'increasing species', mainly Gastropoda, Oligochaeta and Diptera, which showed an increase of frequency from 1.8% at sites with reference conditions to 11.4% at sites with the highest pesticide pressure. Based on the change in frequency we determined the pesticide vulnerability of single species, expressed as Pesticide Associated Response (PARe). Furthermore, a trait analysis revealed that species' occurrence may additionally depend on oxygen demand and, to a lesser extent on substrate preference, whereas no significant effect of feeding and respiration type could be found. Our results provide the first extensive pesticide vulnerability ranking for single macroinvertebrate species based on empirical large-scale field data.


Assuntos
Praguicidas/análise , Poluentes Químicos da Água/análise , Animais , Monitoramento Ambiental , Alemanha , Invertebrados , Rios
12.
Sci Total Environ ; 735: 139243, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32480144

RESUMO

Honey bees (Apis mellifera) provide key ecosystem services as pollinators bridging agriculture, the food chain and ecological communities, thereby ensuring food production and security. Ecological risk assessment of single Plant Protection Products (PPPs) requires an understanding of the exposure and toxicity. In silico tools such as QSAR models can play a major role for the prediction of structural, physico-chemical and pharmacokinetic properties of chemicals as well as toxicity of single and multiple chemicals. Here, the first integrative honey bee QSAR model has been developed for PPPs using EFSA's OpenFoodTox, US-EPA ECOTOX and Pesticide Properties DataBase i) to predict acute contact toxicity (LD50) and ii) to profile the Mode of Action (MoA) of pesticides active substances. Three different classification-based and four regression-based models were developed and tested for their performance, thus identifying two models providing the most reliable predictions based on k-NN algorithm. The two-category QSAR model (toxic/non-toxic; n = 411) was validated using sensitivity (=0.93), specificity (=0.85), balanced accuracy (=0.90), and Matthews correlation coefficient (MCC = 0.78) as statistical parameters. The regression-based model (n = 113) was validated for its reliability and robustness (R2 = 0.74; MAE = 0.52). Current study proposes the MoA profiling for 113 pesticides active substances and the first harmonised MoA classification scheme for acute contact toxicity in honey bees, including LD50s data points from three different databases. The classification allows to further define MoAs and the target site of PPPs active substances, thus enabling regulators and scientists to refine chemical grouping and toxicity extrapolations for single chemicals and component-based mixture risk assessment of multiple chemicals. Relevant future perspectives are briefly addressed to integrate MoA, adverse outcome pathways (AOPs) and toxicokinetic information for the refinement of single-chemical/combined toxicity predictions and risk estimates at different levels of biological organization in the bee health context.


Assuntos
Curadoria de Dados , Praguicidas , Animais , Abelhas , Ecossistema , Relação Quantitativa Estrutura-Atividade , Reprodutibilidade dos Testes
13.
Sci Total Environ ; 735: 139264, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32485446

RESUMO

Aquatic invertebrates exposed to pesticides may develop pesticide resistance. Based on a meta-analysis we revealed environmental factors driving the magnitude of resistance in the freshwater amphipod Gammarus pulex in the field. We showed that (i) insecticide tolerance of G. pulex increased with pesticide contamination in agricultural streams generally by a factor of up to 4. Tolerance increased even at concentrations lower than what is considered safe in regulatory risk assessment (ii) The increase in insecticide tolerance was pronounced at high test concentrations; comparing the LC50 of populations therefore potentially underestimates the development of resistance. (iii) Insecticide resistance in agricultural streams diminished during the spraying season, suggesting that adverse effects of sublethal concentrations in the short term contrast long-term adaptation to insecticide exposure. (iv) We found that resistance was especially high in populations characterized not only by high pesticide exposure, but also by large distance (>3.3 km) from non-polluted stream sections and by low species diversity within the invertebrate community. We conclude that the test concentration, the timing of measurement, distance to refuge areas and species diversity mediate the observed response of aquatic communities to pesticide pollution and need to be considered for the sustainable management of agricultural practices.


Assuntos
Anfípodes , Inseticidas , Praguicidas/análise , Poluentes Químicos da Água/análise , Animais , Água Doce , Rios
14.
Environ Monit Assess ; 192(7): 424, 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32529406

RESUMO

Programs designed to educate farmers on the safe use and application of agrochemicals, and to train them in integrated pest management, are common in developing countries, where the agricultural workers overuse pesticides and fail to use adequate protection. In this study, I evaluate the effects of exposure to both types of programs-the use of pesticides and protection. The data are from the Mekong Delta, which is the most fertile region of Vietnam, produces most of the country's rice and vegetables. The Vietnamese government began such educative campaigns in the late 1990s. The results show that while the abovementioned programs are effective in promoting the use of personal protection, they have less success in reducing the use of pesticides. Moreover, the evidence suggests that the two types of program are substitutes rather than complements.


Assuntos
Fazendeiros , Exposição Ocupacional , Praguicidas , Agricultura , Monitoramento Ambiental , Humanos , Vietnã
15.
Sci Total Environ ; 729: 138922, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32498167

RESUMO

Ecotoxicological risk assessments of pesticides on non-target arthropods are often carried out under constant and optimal temperature regimes. However, living organisms rarely experience these conditions in real field situations. Understanding the impact of pesticides on non-target beneficial arthropods under temperature stresses is especially important in terms of global warming. We assessed the lethal and sublethal effects of four modern insecticides (chlorantraniliprole, cyantraniliprole, spinetoram, spinosad), on the generalist predator Macrolophus pygmaeus (Hemiptera: Miridae) under a range of temperatures (from 10 to 40°C) frequently experienced in a real field scenario. A reduction coefficient (Ex) was calculated by summarizing the mortality and predator reproductive capacity and, the chemicals were classified according to the International Organization for Biological Control (IOBC) toxicity classes. The insecticides showed a marked synergistic effect with temperature, as the predator mortality and reproductive outputs were significantly correlated with increasing temperatures. Spinosyns interacted significantly with temperature causing the highest mortality and lowest fertility rates. Anthranilic diamides showed a safer ecotoxicological profile compared to spinosyns, with cyantraniliprole being more harmful than chlorantraniliprole. These results suggest that temperature should be taken into account in pesticide ecotoxicology studies within the framework of integrated pest management and the recent climate changes.


Assuntos
Heterópteros , Animais , Inseticidas , Controle de Pragas , Praguicidas
16.
Sci Total Environ ; 732: 139118, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32438148

RESUMO

The application of chemical pesticides is one of the main practices in citrus orchards. But during this operation, a considerable amount of sprayed volume is emitted to off-target areas using air-blast sprayers. The present study aimed to investigate pesticides' toxicological impacts in citrus orchards through determining the proportion of pesticides in different areas (air, soil, and canopy), which facilitate toxicity assessment of pesticides in citrus orchards. In this study, human toxicity and freshwater ecotoxicity impacts were assessed using USEtox 2.1 modeling approach for five active ingredients used in citrus orchards in the south of Iran. Different spraying scenarios were defined based on two types of nozzles (Hallow-cone and Teejet full-cone) and three levels of pressure (30, 40, and 50 bar) in two orchards with different row spacing. Results showed that only 26-37% of spray solution is deposited on the target with much loss to areas between tree canopies on the row. Scenario 1 (Hallow-cone nozzle with spraying pressure as 30 bar) shows the highest spraying efficiency in the both orchards (37% and 34% for Tangerine and Lemon orchards, respectively). Air emissions were obtained around 17 and 18% for hollow-cone and Teejet full-cone nozzles, respectively. The final inventory was obtained considering evaporation rate of active ingredients from soil surface and leaves. Based on the results obtained from toxicological impact assessment, Thiacloprid and Carbendazim had the highest negative environmental impacts on human health and freshwater aquatic ecosystem, respectively. Based on the results, soil emissions were identified as more critical than air emissions in terms of environmental consequences. It can be attributed to the higher characterization factor and deposition on the soil in comparison to the air. The present study provided well-founded information on the environmental performance of production systems by estimating the relevant emissions of pesticides to different compartments and determined the human and freshwater toxicity impact profiles, which assist decision-makers and LCA-practitioners to have a better perspective about pesticides behavior in receiving compartment.


Assuntos
Citrus , Ecossistema , Água Doce , Irã (Geográfico) , Praguicidas
17.
Chemosphere ; 254: 126902, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32361539

RESUMO

This study presents monitoring data on the spatial and temporal occurrence of pesticide residues in arable soils of the Czech Republic and relates it to soil properties, pesticide usage and data on application provided by farmers. In total, 34 soils were sampled during 2014-2017, amounting to 136 samples which were analyzed for 60 pesticides and four transformation products. Conazole fungicides were frequently present in soils above the limit of quantification and/or above the 0.01 mg/kg threshold. Of the other pesticide types, the herbicides diflufenican, chlorotoluron, metolachlor, pendimethalin and terbuthylazine, fungicides azoxystrobin, carbendazim, fenpropidin, fenpropimorph and prochloraz and the insecticide methoxyfenozide were found in ≥20% of soils in at least one sampling campaign. Soils typically (>50%) contained 2-7 residues with a maximum of 14. For the 136 samples, 116 different mixtures were identified. The occurrence of pesticides was driven by their annual usage, their half-lives in soil, and their hydrophobicity. A comparison of the monitoring data and pesticide application data provided by farmers revealed that 63% of the applied pesticides are not likely to persist until the following growing season while up to 69% of pesticide residues found in soils could be inherited from the previous growing season(s).


Assuntos
Monitoramento Ambiental , Praguicidas/análise , Poluentes do Solo/análise , Compostos de Anilina , República Tcheca , Fungicidas Industriais/análise , Herbicidas/análise , Inseticidas/análise , Resíduos de Praguicidas/análise , Solo/química , Triazinas
18.
Chemosphere ; 254: 126875, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32361544

RESUMO

In the present scenario, insecticides/pesticides are used intensively to control the various insect pests. Indiscriminate use of these insecticides/pesticides affects the structure and function of the ecosystem. In this context, a thorough toxicological study of each insecticide/pesticide is a must to understand the hazardous effect of these chemicals on the target and non-target organisms. The present study was aimed to understand the hazardous effect of thiamethoxam against the Spodoptera litura. Different concentrations (20-80 µg/mL) of thiamethoxam were prepared, and fourth instar larvae of S. litura were allowed to feed for 12-72 h. We first examined the interaction of thiamethoxam with DNA. Next, treated and non-treated larvae were assessed for different biological parameters such as mortality, emergence, fecundity, fertility, longevities, and biochemical parameters. Our result showed that thiamethoxam directly interacts with the DNA and significantly influenced the different biological and biochemical parameters of exposed the organisms. We observed a significant change in stress enzymes such as SOD, CAT, and GST. A similar observation was also made with the oxidative marker for lipid damage, MDA and DNA damage, 8-OHdG, respectively. In conclusion, our results suggest that improper use of synthetic chemical insecticides influenced both biological and biochemical parameters through oxidative stress and probably damage the genetic material.


Assuntos
DNA/efeitos dos fármacos , Inseticidas/toxicidade , Tiametoxam/toxicidade , Animais , Dano ao DNA , Ecossistema , Insetos , Larva/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Praguicidas/farmacologia , Spodoptera/efeitos dos fármacos
19.
Arch Environ Contam Toxicol ; 79(1): 12-22, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32447405

RESUMO

This study measured both nutrient and pesticide concentrations at up to 13 different freshwater stream sites in New Brunswick, Nova Scotia and Prince Edward Island between 2013 and 2018. Up to 62 different pesticides were analysed in 248 discreet samples. A large majority of pesticides were below the detection limit of the laboratory while seven pesticides had at least 20% or more detections throughout the years of this study. The four pesticides that had the highest frequency of detection were the insecticides chlorantraniliprole, clothianidin, imidacloprid, and thiamethoxam of which the last three are categorised as neonicotinoid insecticides.


Assuntos
Monitoramento Ambiental/métodos , Praguicidas/análise , Rios/química , Poluentes Químicos da Água/análise , Canadá , Guanidinas/análise , Neonicotinoides/análise , Nitrocompostos/análise , Análise Espaço-Temporal , Tiametoxam/análise , Tiazóis/análise
20.
Ecotoxicol Environ Saf ; 200: 110734, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32464440

RESUMO

Microorganisms' role in pesticide degradation has been studied widely. Insitu treatments of effluents containing pesticides such as biological beds (biobeds) are efficient biological systems where biomixture (mixture of substrates) and microorganisms are the keys in pesticide treatment; however, microbial activity has been studied poorly, and its potential beyond biobeds has not been widely explored. In this study, the capacity of microbial consortium and bacteria-pure strains isolated from a biomixture (soil-straw; 1:1, v/v) used to treat agricultural effluents under real conditions were evaluated during a bioremediation process of five pesticides commonly used Yucatan Mexico. Atrazine, carbofuran, and glyphosate had the highest degradations (>90%) using the microbial consortium; 2,4-D and diazinon were the most persistent (DT50 = 8.64 and 6.63 days). From the 21 identified bacteria species in the microbial consortium, Pseudomonas nitroreducens was the most abundant (52%) according to identified sequences. For the pure strains evaluation 2,4-D (DT50 = 9.87 days), carbofuran (DT50 = 8.27 days), diazinon (DT50 = 8.80 days) and glyphosate (DT50 = 8.59 days) were less persistent in the presence of the mixed consortium (Ochrobactrum sp. DGG-1-3, Ochrobactrum sp. Ge-14, Ochrobactrum sp. B18 and Pseudomonas citronellolis strain ADA-23B). Time, pesticide, and strain type were significant (P < 0.05) in pesticide degradation, so this process is multifactorial. Microbial consortium and pure strains can be used to increase the biobed efficiency by inoculation, even in the remediation of soil contaminated by pesticides in agricultural areas.


Assuntos
Bactérias/metabolismo , Consórcios Microbianos , Praguicidas/metabolismo , Poluentes do Solo/metabolismo , Ácido 2,4-Diclorofenoxiacético/metabolismo , Agricultura , Atrazina/metabolismo , Bactérias/isolamento & purificação , Biodegradação Ambiental , Carbofurano/metabolismo , Diazinon/metabolismo , Glicina/análogos & derivados , Glicina/metabolismo , Pseudomonas/isolamento & purificação , Solo/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA