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1.
Chemosphere ; 247: 125728, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32069706

RESUMO

Systemic insecticides are used to control agricultural pests globally and their non-target impact at non-lethal doses on beneficial arthropods has been recognized. We assessed the baseline toxicity of imidacloprid, thiamethoxam and sulfoxaflor-based insecticides on the polyphagous aphid pest, Aphis gossypii (Hemiptera: Aphididae), and their non-target effects on its main parasitoid, Aphidius colemani (Hymenoptera: Braconidae), evaluated by residual contact exposure to the median lethal (LC50), the low lethal (LC20) and the sublethal (LC1) concentrations of the three tested insecticides, earlier estimated for the target pest. The results showed that the LC50s for the aphid were 6.4 × 10-3, 5 × 10-3, 2.9 × 10-2 times lower compared to the label concentrations of imidacloprid, thiamethoxam and sulfoxaflor, respectively. LC50 of thiamethoxam caused the highest mortality rate on the parasitoid followed by sulfoxaflor, while imidacloprid had the lowest impact. No significant sublethal effects on reprodution were observed for A. colemani survived to the insecticide exposure. Our findings highlight the importance of case-specific evaluation to optimize pesticide applications in Integrated Pest Management packages taking into account the ecological services provided by biological control agents.


Assuntos
Afídeos/efeitos dos fármacos , Himenópteros/efeitos dos fármacos , Inseticidas/toxicidade , Animais , Agentes de Controle Biológico/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Tiametoxam/toxicidade
2.
Ecotoxicol Environ Saf ; 187: 109849, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31677571

RESUMO

Harmonia axyridis is an important predator of several pest species and is part of many Integrated Pest Management (IPM) programs. To assess the risks of pesticide application to H. axyridis, we studied the effects of sulfoxaflor on H. axyridis larvae. At 72 h after treatment, the acute toxicity LR50 was 311.9476 g a. i. ha-1 by the residual contact method. This result indicated low-contact toxicity against second-instar H. axyridis larvae. The LR50 of the F1 generation decreased from 69.96 to 36.41 g a. i. ha-1 in a long-term toxicity test. The daily hazard quotient (HQ) for H. axyridis larvae lowered the safety threshold value in the first 5 d. However, the HQ values were greater than 2 during days 6-18 after sulfoxaflor treatments. We determined the No Observed Effect Application Rates of sulfoxaflor on the survival (<11.25 g a. i. ha-1), duration of larval and pupal stages (45 g a. i. ha-1), adult stage (90 g a. i. ha-1), total pre-oviposition period, adult pre-oviposition period (45 g a. i. ha-1), and reproduction (11.25 g a. i. ha-1). Pupation, adult emergence, and eggs counts of H. axyridis were reduced after sulfoxaflor treatments. The predation ability and population demography parameters were significantly impaired by higher application rates. At 90 g a. i. ha-1 or less, sulfoxaflor was slightly harmful to H. axyridis but a rate of 180 g a. i. ha-1 was moderately harmful. These results demonstrated that sulfoxaflor is harmful to H. axyridis when applied at high application rates.


Assuntos
Besouros/efeitos dos fármacos , Larva/efeitos dos fármacos , Resíduos de Praguicidas/toxicidade , Pupa/efeitos dos fármacos , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Animais , Besouros/fisiologia , Relação Dose-Resposta a Droga , Feminino , Larva/fisiologia , Dose Letal Mediana , Controle de Pragas , Comportamento Predatório/efeitos dos fármacos , Pupa/fisiologia , Reprodução/efeitos dos fármacos , Testes de Toxicidade
3.
Neurotoxicology ; 72: 29-37, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30738091

RESUMO

Persulfate salts are broadly used as industrial chemicals and exposure to them causes occupational asthma, occupational rhinitis and contact dermatitis. However, the mechanisms underlying these toxic actions are not fully elucidated. Transient receptor potential (TRP) vanilloid 1 (V1), ankyrin 1 (A1) and melastatin 8 (M8) are non-selective cation channels preferentially expressing sensory neurons. These channels are known to be involved in respiratory and skin diseases. In the present study, we investigated the effects of sodium persulfate on these TRP channels. In wild-type mouse sensory neurons, persulfate evoked [Ca2+]i increases that were inhibited by removal of extracellular Ca2+ or blockers of TRPA1 but not by those of TRPV1 and TRPM8. Persulfate failed to evoke [Ca2+]i responses in neurons from TRPA1(-/-) mice, but did evoke them in neurons from TRPV1(-/-) mice. In HEK 293 cells expressing mouse TRPA1 (mTRPA1-HEK), persulfate induced [Ca2+]i increases. Moreover, in HEK 293 cells expressing mouse TRPV1 (mTRPV1-HEK), a high concentration of persulfate also evoked [Ca2+]i increases. Similar [Ca2+]i responses were observed in HEK 293 cells expressing human TRPA1 and human TRPV1. Current responses were also elicited by persulfate in mTRPA1- and mTRPV1-HEK. Analysis using mutated channels revealed that persulfate acted on electrophilic agonist-sensitive cysteine residues of TRPA1, and it indirectly activated TRPV1 due to the external acidification, because of the disappearance of [Ca2+]i responses in acid-insensitive mTRPV1 mutant. These results demonstrate that persulfate activates nociceptive TRPA1 and TRPV1 channels. It is suggested that activation of these nociceptive channels may be involved in respiratory and skin injuries caused by exposure to this industrial sulfur compound. Thus, selective TRPA1 and TRPV1 channel blockers may be effective to remedy persulfate-induced toxic actions.


Assuntos
Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Compostos de Enxofre/toxicidade , Enxofre/toxicidade , Canal de Cátion TRPA1/metabolismo , Canais de Cátion TRPV/metabolismo , Cálcio/metabolismo , Poluentes Ambientais/toxicidade , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Células HEK293 , Humanos , Canal de Cátion TRPA1/agonistas , Canal de Cátion TRPA1/antagonistas & inibidores
4.
J Agric Food Chem ; 66(45): 11902-11908, 2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30372061

RESUMO

Testing for effects of pesticides on nontarget organisms is an integral part of ecological risk assessment. In the present study, the acute toxicity of sulfoxaflor to earthworms was evaluated using an artificial soil toxicity test, and sublethal effects were assessed through oxidative stress and metabolomics. Sulfoxaflor is a supertoxic pollutant to earthworms that easily bioaccumulates in earthworms, and contains LC2, LC10, and LC50 values of 0.08 (0.04-0.13), 0.19 (0.11-0.25), and 0.54 (0.45-0.65) mg/kg, respectively. Sublethal doses of sulfoxaflor resulted in oxidative damage to earthworms in which antioxidant enzymatic activities including SOD, CAT, and GST were significantly inhibited and MDA content accumulated. Metabolomics analysis suggested that the energy metabolism and the urea cycle in earthworms were significantly activated, while nucleotide metabolism was depressed, which could cause DNA damage. The results suggest earthworms have the potential to be a new entry point for sulfoxaflor into the wildlife food chain. Since earthworms significantly contribute to soil function and ecosystems, the high safety risks of sulfoxaflor to the earthworm could extend to the environment. In view of these findings, more attention should be given to the risks sulfoxaflor poses to the environment through its effects on earthworms.


Assuntos
Oligoquetos/efeitos dos fármacos , Praguicidas/toxicidade , Piridinas/toxicidade , Poluentes do Solo/toxicidade , Compostos de Enxofre/toxicidade , Animais , Catalase/genética , Catalase/metabolismo , Dano ao DNA/efeitos dos fármacos , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Malondialdeído/metabolismo , Oligoquetos/genética , Oligoquetos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
5.
Ecotoxicol Environ Saf ; 155: 37-42, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-29500938

RESUMO

2,2'-Thiodiacetates with their excellent complexing properties may be used as metal extraction agents, fluorescent and superparamagnetic materials, antibacterial and anticancer medical agents, however there are no data concerning the environmental impact of 2,2'-thiodiacetates derivatives and data definying the potential hazard connected with their use. This study describes the ecotoxicity assessment of seven 2,2'-thiodiacetates with non-metallic, alkyl and aryl ammonium cations, which were obtained in an environmentally friendly, solvent-free syntheses. The ecotoxicity of these water soluble compounds was tested in aquatic and benthic environments using luminescent marine bacteria Vibrio fischeri (Microtox® test) and the crustaceans Heterocypris incongruens (Ostracodtoxkit F™), respectively. The antimicrobial and antifungal activity against Trichoderma viridis, Aspergillus niger, Rhizoctonia solani and Escherichia coli was also investigated. The results showed how structural changes within ammonium cations themselves influence ecotoxicity: the QASs with alkylammonium cations exhibited a similar, rather low toxicity both to Vibrio fischeri and Heterocypris incongruens, and they would not pose a risk to these organisms in case of leakage. Higher toxicity was observed in case of two isoquinolinium salts, however it was rather associated with the heteroaromatic cation, than with the 2,2'-thiodiacetate anion.


Assuntos
Acetatos/química , Acetatos/toxicidade , Compostos de Enxofre/química , Compostos de Enxofre/toxicidade , Acetatos/farmacologia , Aliivibrio fischeri/efeitos dos fármacos , Compostos de Amônio/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Cátions , Crustáceos/efeitos dos fármacos , Sais , Compostos de Enxofre/farmacologia
6.
Pestic Biochem Physiol ; 144: 57-63, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29463409

RESUMO

The mirid bug, Apolygus lucorum (Meyer-Dür) has evolved the resistance towards some traditional insecticides, especially pyrethroids and organophosphates. Sulfoxaflor, as a novel insecticide, is used for control of sap-feeding insects, like A. lucorum. Therefore, it is necessary to determine the acute toxicity and the potential sublethal effects of sulfoxaflor in A. lucorum. Here, the LD50 value of sulfoxaflor against A. lucorum was assayed as 3.347ng/adult at 48h via topical application. Besides, the effects of a sublethal dose (LD15) of sulfoxaflor on biological characteristics of A. lucorum were estimated by comparison of the life table parameters. The longevities and fecundity of parent generation did not exhibited significant difference between both control and treatment groups after exposure to LD15 dose of sulfoxaflor (0.568ng/adult) for 48-h. However, the parameters reflecting their progeny G1 generation population dynamics, including the intrinsic rate of increase (ri), the finite rate of increase (λ), the mean generation time (T), the net reproductive rate (R0) and gross reproduction rate (GRR) significantly reduced in the treatment group compared to the control. Furthermore, the expression level of AlVg mRNA significantly decreased by 43.8% in the progeny whose parents were treated with LD15 dose of sulfoxaflor in comparison with the control transgenerational female adults. These results suggested that sublethal dose of sulfoxaflor adversely affect the development and reproduction of transgenerational A. lucorum. The downregulation of AlVg might have negative impacts on the fecundity of A. lucorum.


Assuntos
Expressão Gênica/efeitos dos fármacos , Heterópteros/genética , Resistência a Inseticidas/genética , Inseticidas/toxicidade , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Vitelogeninas/genética , Animais , Feminino , Fertilidade/efeitos dos fármacos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Testes de Toxicidade , Testes de Toxicidade Subaguda
7.
Pestic Biochem Physiol ; 143: 90-94, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29183616

RESUMO

Sulfoxaflor (SFX, Isoclast™ Active) is a recently developed sulfoximine insecticide that is highly effective against sap-feeding insect pests. SFX has been shown to act through an interaction with insect nicotinic acetylcholine receptors (nAChRs). SFX was previously found to interact weakly with the binding site for the neonicotinoid imidacloprid. However, radioligand displacement studies characterizing the binding site of the insecticide SFX itself have not been conducted. In this study, we report the characterization of a high affinity [3H]SFX Myzus persicae (green peach aphid, GPA) binding site with relatively low abundance. Through the evaluation of a set of SFX analogs, we have demonstrated that displacement of [3H]SFX shows an excellent correlation with GPA toxicity, and thus is toxicologically relevant. Comparison with the previously described methyl-SFX binding site information reveals differences with the SFX binding site that are discussed herein. [3H]SFX therefore represents a new tool for the characterization of insect nAChRs.


Assuntos
Inseticidas/toxicidade , Neonicotinoides/toxicidade , Piridinas/toxicidade , Receptores Nicotínicos/metabolismo , Compostos de Enxofre/toxicidade , Animais , Afídeos/efeitos dos fármacos , Afídeos/metabolismo , Sítios de Ligação
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 180: 127-137, 2017 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-28284158

RESUMO

Vanadium(III) tris(dithiocarbonates), [(ROCS2)3V] (R=o-, m-, p-CH3C6H4 and 4-Cl-3-CH3C6H3) and donor stabilized addition complexes [(ROCS2)2V(Cl)·L] [L=NC5H5 or P(C6H5)3] were synthesized and characterized by elemental analyses, IR, mass, TGA/DTA, SEM magnetic susceptibility and heteronuclear NMR (1H, 13C and 31P) spectroscopic studies. The cytotoxicity of the complexes was measured in vitro using the cultivated human cell lines. In addition, the antioxidant activities of the ligands and its vanadium complexes were also investigated through their scavenging effect on DPPH radicals. The antimicrobial activity of ligands and some complexes has been conducted against three bacterial strains and fungus. The density functional theory (DFT) calculations of ligands and vanadium complexes were performed by the DFT/B3LYP/LANL2DZ method to obtain the optimized molecular geometry, vibrational frequencies, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), thermodynamic properties and various other quantum-mechanical parameters.


Assuntos
Carbonatos , Compostos de Enxofre , Vanádio , Anti-Infecciosos/química , Anti-Infecciosos/toxicidade , Bactérias/efeitos dos fármacos , Carbonatos/química , Carbonatos/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Complexos de Coordenação/toxicidade , Fungos/efeitos dos fármacos , Humanos , Espectroscopia de Ressonância Magnética , Compostos de Enxofre/química , Compostos de Enxofre/toxicidade , Termogravimetria , Vanádio/química , Vanádio/toxicidade
9.
Ecotoxicol Environ Saf ; 139: 377-383, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28189779

RESUMO

To understand whether sulfoxaflor, a novel neonicotinoid, poses unacceptable risks to the environment, it is important to assess its effects on nontarget insects. Therefore, the effects of short-term exposure (28 days) of free-feeding sublethal concentrations (1-2µg/ml) of sulfoxaflor to the red imported fire ant, Solenopsis invicta, were investigated. The following parameters were evaluated to determine the impact of exposure: colony growth, food consumption (sugar water and locusts), and interspecific interactions. Sulfoxaflor exposure produced significant negative effects on S. invicta colony growth, with cumulative colony weight losses of 83.36% and 100.00% after treatment with 1µg/ml and 2µg/ml, respectively. The consumption of sugar water (containing sulfoxaflor) of surviving colonies decreased with increasing sulfoxaflor concentration. Moreover, the consumption of locusts decreased after treatment with 2µg/ml, but not 1µg/ml, sulfoxaflor. Sulfoxaflor treatment for 14 days led to reduced aggressiveness of S. invicta workers in interspecific confrontations (S. invicta vs. unexposed Pheidole fervida), and their probability of survival of aggressive encounters was reduced significantly to 48% of that of control ants. Our results indicate that sublethal concentrations of sulfoxaflor are likely to have a negative impact on ants.


Assuntos
Agressão/efeitos dos fármacos , Formigas , Comportamento Alimentar/efeitos dos fármacos , Inseticidas/toxicidade , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Animais , Formigas/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Fatores de Tempo
10.
Pestic Biochem Physiol ; 136: 41-45, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28187829

RESUMO

Acetolactate synthase (ALS) is the common target of ALS-inhibiting herbicides, and target-site ALS mutations are the main mechanism of resistance to ALS-inhibiting herbicides. In this study, ALS1 and ALS2 genes with full lengths of 2004bp and 1998bp respectively were cloned in individual plants of susceptible (S) or resistant (R) flixweed (Descurainia sophia L.) populations. Two ALS mutations of Pro-197-Thr and/or Trp-574-Leu were identified in plants of three R biotypes (HB24, HB30 and HB42). In order to investigate the function of ALS isozymes in ALS-inhibiting herbicide resistance, pHB24 (a Pro-197-Thr mutation in ALS1 and a wild type ALS2), pHB42 (a Trp-574-Leu mutation in ALS1 and a wild type ALS2) and pHB30 (a Trp-574-Leu mutation in ALS1 and a Pro-197-Thr mutation in ALS2) subpopulations individually homozygous for different ALS mutations were generated. Individuals of pHB30 had mutations in each isozyme of ALS and had higher resistance than pHB24 and pHB42 populations containing mutations in only one ALS isozyme. Moreover, the pHB24 had resistance to SU, TP and SCT herbicides, whereas pHB24 and pHB42 had resistance to these classes of herbicides as well as IMI and PTB herbicides. The sensitivity of isolated ALS enzyme to inhibition by herbicides in these populations correlated with whole plant resistance levels. Therefore, reduced ALS sensitivity resulting from the mutations in ALS was responsible for resistance to ALS-inhibiting herbicides in flixweed.


Assuntos
Acetolactato Sintase/genética , Brassicaceae/genética , Resistência a Herbicidas/genética , Proteínas de Plantas/genética , Plantas Daninhas/genética , Acetolactato Sintase/antagonistas & inibidores , Acetolactato Sintase/metabolismo , Benzofenonas/toxicidade , Brassicaceae/efeitos dos fármacos , Brassicaceae/enzimologia , Herbicidas/toxicidade , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Mutação , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/metabolismo , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/enzimologia , Plântula/efeitos dos fármacos , Plântula/genética , Compostos de Enxofre/toxicidade
11.
Pestic Biochem Physiol ; 136: 46-51, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28187830

RESUMO

Control of Bemisia tabaci has depended primarily and heavily on insecticides, especially neonicotinoids. The novel sulfoximine insecticide sulfoxaflor exhibits high potency against a broad range of sap-feeding insect species, including those resistant to neonicotinoids. The resistance levels of Q-biotype B. tabaci field strains collected from 8 locations in eastern China to neonicotinoids and sulfoxaflor were investigated, and single nucleotide polymorphisms (SNPs) of nicotinic acetylcholine receptor ß1 subunit gene (Btß1) were detected. Compared with the reference strain, the field strains had developed low to moderate levels of resistance to imidacloprid and nitenpyram with the resistance ratios (RR) ranging between 4.07 and 21.75-fold and 3.37 and 16.14-fold, respectively. While YZ strain exhibited high resistance (RF 40.38) to thiamethoxam, only low levels of resistance to thiamethoxam (RF 3.50-8.58) was observed in other strains. All strains were relatively susceptible to both dinotefuran (RF 0.50-2.55) and sulfoxaflor (RF 0.40-3.07). Sequence analysis of Btß1 cDNA fragments revealed 23 SNPs representing 19 amino acid replacements in these strains. Notably, a 45bp fragment deletion was detected in JY strain, which encodes 15 amino acid residues (positions 66-80) containing arginine at position 79 (R79) corresponding to the R81T mutation in Loop D of nAChR ß1 subunit in Myzus persicae resistant to neonicotinoids. The lack of cross-resistance indicates that both dinotefuran and sulfoxaflor could play an important role in the control of B. tabaci already resistant to the first and second generation neonicotinoids.


Assuntos
Hemípteros/efeitos dos fármacos , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Inseticidas/toxicidade , Subunidades Proteicas/genética , Receptores Nicotínicos/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , China , Clonagem Molecular , DNA Complementar/genética , Feminino , Guanidinas/toxicidade , Hemípteros/genética , Imidazóis/toxicidade , Masculino , Neonicotinoides , Nitrocompostos/toxicidade , Oxazinas/toxicidade , Polimorfismo de Nucleotídeo Único , Piridinas/toxicidade , Análise de Sequência de DNA , Compostos de Enxofre/toxicidade , Tiametoxam , Tiazóis/toxicidade
12.
J Econ Entomol ; 110(1): 52-58, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28039423

RESUMO

Flupyradifurone and sulfoxaflor present novel insecticide chemistries with particular efficacy against aphids, and the recent emergence of sugarcane aphid, Melanaphis sacchari (Zehntner), as a pest of sorghum in the United States has resulted in their widespread use. We examined their toxicity to Hippodamia convergens Guerin-Meneville, an important aphid biocontrol agent. We exposed beetles to topical applications of the field rate (FR) of these insecticides, fed them contaminated food (eggs of Ephestia kuehniella Zeller), and gave first-instar larvae 24-h exposures to leaf residues. More than half of fourth-instar larvae receiving topical applications of sulfoxaflor at FR survived, whereas flupyradifurone at 0.1× FR caused 90% mortality. Adults survived topical treatments better than larvae and without measurable mortality, except flupyradifurone at FR, which killed more than 80% of beetles. Survivors of all treatments had fertility similar to controls, whether treated as larvae or adults. Ingestion of contaminated food caused significant mortality in all treatments (15-40% for adults and 55-85% for larvae), with no significant differences between insecticides at FR. Leaf residues of sulfoxaflor at 1.0 and 2.0× FR caused approximately 60 and 80% mortality of first instars, respectively, whereas flupyradifurone at 0.1 and 1.0× FR caused > 90% mortality. Although sulfoxaflor was less toxic to H. convergens than flupyradifurone, the tested FR of flupyradifurone has now been reduced by half. We conclude that neither insecticide appears as toxic as other nicotinic acetylcholine receptor agonists, and that both materials are compatible with integrated pest management programs for M. sacchari.


Assuntos
4-Butirolactona/análogos & derivados , Besouros/efeitos dos fármacos , Controle de Insetos , Inseticidas/toxicidade , Controle Biológico de Vetores , Comportamento Predatório/efeitos dos fármacos , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , 4-Butirolactona/toxicidade , Animais , Besouros/crescimento & desenvolvimento , Feminino , Larva/efeitos dos fármacos
13.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 42(12): 1417-1424, 2017 Dec 28.
Artigo em Chinês | MEDLINE | ID: mdl-29317583

RESUMO

OBJECTIVE: To explore the relationship between air pollution and the number of pneumonia hospitalization in a children's hospital in Changsha.
 Methods: Children who have been in this hospital for the treatment of pneumonia between December 2013 and December 2015 were enrolled in this study. Based on daily meteorological data and air pollution data from December 2013 to December 2015 in Changsha, we constructed a generalized additive model to analyze the relationship between air pollution and the number of pneumonia hospitalization.
 Results: During the research, the average concentration of PM2.5 and PM10 exceeded the Grade II national standards for air quality. The average concentration of SO2 exceeded the Grade I national standards. The change of all the 3 main air pollution indexes showed strong statistical relationship with the change of the number of pneumonia hospitalization (P<0.05), among which, the impact of SO2 ranked number 1, followed by PM2.5 and PM10. Effect of atmospheric pollution on the number of pneumonia boys was basically same as that in the total pneumonia children (P<0.05). The effect on girls showed no statistical relationship in both models (P>0.05).
 Conclusion: The concentrations of SO2, PM2.5 and PM10 are positively correlated with pneumonia hospitalization number of children, and their effect on boys is more obvious than that in the girls.


Assuntos
Poluentes Atmosféricos/toxicidade , Poluição do Ar/efeitos adversos , Hospitalização/estatística & dados numéricos , Pneumonia/epidemiologia , Criança , China/epidemiologia , Feminino , Hospitais Pediátricos/estatística & dados numéricos , Humanos , Masculino , Óxidos/toxicidade , Material Particulado/toxicidade , Fatores Sexuais , Compostos de Enxofre/toxicidade
14.
Ecotoxicology ; 25(10): 1841-1848, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27670668

RESUMO

Sulfoxaflor is a novel insecticide belonging to sulfoximine chemical class that can be used to control sap-feeding insects, notably Aphis gossypii Glover. In addition to its acute toxicity, it is also important to consider the possible sublethal effects when establishing a comprehensive understanding of the toxicity of a new insecticide. We assessed the effects of a low lethal concentration (LC25) of sulfoxaflor on biological parameters of A. gossypii adults (F0) and subsequent transgenerational effects, i.e., on the progeny (F1 generation). The data were analyzed using an age-stage life table procedure. The results showed that the longevity and fecundity were not significantly affected by the LC25 of sulfoxaflor in the F0 or F1 generations. In addition, no significant differences were observed on the developmental time of each instar, the adult pre-oviposition period, and on the longevity of F1 individuals. However, the duration of their pre-adult stage and total pre-oviposition period, as well as their mean generation time were significantly increased. These observed effects affected aphid demographic traits; the survival rate, the intrinsic rate of increase (r i ), the finite rate of increase (λ), the net reproductive rate (R0), and the gross reproduction rate (GRR) of the F1 individuals (i.e., from F0 mothers) were significantly lower compared to the control. Our results showed that sublethal effects of sulfoxaflor significantly slowed down A. gossypii population growth; they indicated that effects of sulfoxaflor might be increased (beyond lethal effect) through sublethal effects when concentrations decreased in sulfoxaflor-treated areas after initial application in field.


Assuntos
Afídeos/efeitos dos fármacos , Inseticidas/toxicidade , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Testes de Toxicidade , Animais , Fertilidade , Longevidade , Reprodução
15.
J Econ Entomol ; 109(5): 2105-14, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27535848

RESUMO

Soybean aphid, Aphis glycines Matsumura, is one of the most important insect pests of soybean in the north central United States. Management of A. glycines currently relies on applications of broad-spectrum insecticides. However, broad-spectrum insecticides can negatively impact the natural enemies associated with aphids. Selective insecticides, on the other hand, are promising control tactics for reducing the negative impact of insecticide applications. Here, we compared the effects of sulfoxaflor (a new selective insecticide) and broad-spectrum insecticides on A. glycines and predators in a two-year field experiment. We sampled A. glycines and aphid predator populations using visual whole-plant inspection. In addition, sweep-net sampling was performed to monitor predator populations. To evaluate the toxicity of the insecticides on predator populations, laboratory bioassays were performed on Hippodamia convergens Guérin-Méneville, Orius insidiosus (Say), and Chrysoperla rufilabris (Burmeister). Field results showed that sulfoxaflor was as effective as the broad-spectrum insecticide in suppressing soybean aphid populations and was less impactful on predator populations. The laboratory bioassays showed that sulfoxaflor was moderately harmful to O. insidiosus, harmless to slightly harmful to H. convergens, and harmless to C. rufilabris These studies suggest that sulfoxaflor holds promise for improving integration of chemical and biological controls for A. glycines management.


Assuntos
Insetos/efeitos dos fármacos , Inseticidas/toxicidade , Comportamento Predatório/efeitos dos fármacos , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Animais , Afídeos/efeitos dos fármacos , Afídeos/crescimento & desenvolvimento , Besouros/efeitos dos fármacos , Besouros/crescimento & desenvolvimento , Heterópteros/efeitos dos fármacos , Heterópteros/crescimento & desenvolvimento , Controle de Insetos , Insetos/crescimento & desenvolvimento , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Minnesota , Ninfa/efeitos dos fármacos , Ninfa/crescimento & desenvolvimento , Controle Biológico de Vetores , Piridinas/farmacologia , Soja/crescimento & desenvolvimento , Compostos de Enxofre/farmacologia
16.
Toxicol Sci ; 154(1): 90-100, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27492223

RESUMO

Dietary administration is a relevant route of oral exposure for regulatory toxicity studies of agrochemicals as it mimics potential human intake of the chemical via treated crops and commodities. Moreover, dietary administration of test compounds during a developmental toxicity study can deliver a prolonged and stable systemic exposure to the embryo or fetus at all stages of development. In this study, strategies were employed to optimize rabbit test material consumption via diet. Comparative toxicokinetic profiles of gavage versus dietary administration were evaluated in pregnant or non-pregnant New Zealand White rabbits for 2 novel agrochemicals with different plasma half-lives of elimination (sulfoxaflor, t½ = 13.5 h and halauxifen, t½ = 1 h). Dietary administration of sulfoxaflor resulted in stable 24-h plasma concentrations, whereas gavage administration resulted in a 3-fold fluctuation in plasma levels between Cmax and Cmin Dietary administration of sulfoxaflor resulted in a 2-fold higher nominal and diurnal systemic dose when compared with gavage dosing due to Cmax-related maternal toxicity following gavage. Results with the shorter half-life molecule, halauxifen, were more striking with a 6-fold diurnal fluctuation by the dietary route compared with a 368-fold fluctuation between Cmax and Cmin by gavage. Furthermore, plasma halauxifen was detectable only up to 12 h following gavage but up to 24 h following dietary administration. Finally, the presence of these compounds in fetal blood samples was demonstrated, confirming that dietary exposure is appropriate for achieving fetal exposure. Collectively, the results of these studies support the use of dietary exposure in rabbit developmental toxicity studies.


Assuntos
Administração Oral , Agroquímicos/toxicidade , Testes de Toxicidade/métodos , Animais , Dieta , Feminino , Feto , Meia-Vida , Gravidez , Piridinas/sangue , Piridinas/toxicidade , Coelhos , Compostos de Enxofre/sangue , Compostos de Enxofre/toxicidade , Toxicocinética
17.
Pest Manag Sci ; 72(9): 1752-7, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26662118

RESUMO

BACKGROUND: The beneficial fungus Neozygites floridana kills the two-spotted spider mite Tetranychus urticae, which is a serious polyphagous plant pest worldwide. Outbreaks of spider mites in strawberry and soybean have been associated with pesticide applications. Pesticides may affect N. floridana and consequently the natural control of T. urticae. N. floridana is a fungus difficult to grow in artificial media, and for this reason, very few studies have been conducted with this fungus, especially regarding the impact of pesticides. The aim of this study was to conduct a laboratory experiment to evaluate the effect of pesticides used in strawberry and soybean crops on N. floridana. RESULTS: Among the pesticides used in strawberry, the fungicides sulfur and cyprodinil + fludioxonil completely inhibited both the sporulation and conidial germination of N. floridana. The fungicide fluazinam affected N. floridana drastically. The application of the fungicide tebuconazole and the insecticides fenpropathrin and abamectin resulted in a less pronounced negative effect on N. floridana. Except for epoxiconazole and cyproconazole, all tested fungicides used in soybean resulted in a complete inhibition of N. floridana. Among the three insecticides used in soybean, lambda-cyhalothrin and deltamethrin resulted in a significant inhibition of N. floridana. CONCLUSION: The insecticides/ acaricides abamectin and lambda-cyhalothrin at half concentrations and fenpropathrin and permethrin and the fungicide tebuconazole at the recommended concentrations resulted in the lowest impact on N. floridana. The fungicides with the active ingredients sulfur, cyprodinil + fludioxonil, azoxystrobin, azoxystrobin + cyproconazole, trifloxystrobin + tebuconazole and pyraclostrobin + epoxiconazole negatively affected N. floridana. © 2015 Society of Chemical Industry.


Assuntos
Acaricidas/toxicidade , Entomophthorales/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Inseticidas/toxicidade , Compostos de Enxofre/toxicidade , Animais , Agentes de Controle Biológico , Brasil , Fragaria/crescimento & desenvolvimento , Noruega , Controle Biológico de Vetores , Soja/crescimento & desenvolvimento , Esporos Fúngicos/efeitos dos fármacos , Tetranychidae/microbiologia
18.
J Econ Entomol ; 108(6): 2720-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26470367

RESUMO

The green peach aphid, Myzus persicae (Sulzer), is an important insect pest of many crops around the world. Pesticide-induced hormesis may be an alternative mechanism for pest resurgence. In this study, life table parameters were applied to the estimation of sulfoxaflor-induced hormesis of adult M. persicae following 2-d LC25 concentration exposure. Leaf-dip bioassays showed that the sulfoxaflor possessed high toxicity against M. persicae, with an LC50 of 0.059 mg/liter. The results indicated that the exposure of the parent generation of M. persicae to sublethal sulfoxaflor induced increase in reproduction and prolongation of immature development duration in the first progeny generation. Both R0 and GRR of aphids for treatment group were significantly higher than for the control in F1 generation, and the mean generation time was significantly postponed in treated group. These results suggest a hormesis induced by lower concentration of sulfoxaflor in M. persicae. It would be useful for assessing the overall effects of sulfoxaflor on M. persicae.


Assuntos
Afídeos/efeitos dos fármacos , Imidazóis/toxicidade , Inseticidas/toxicidade , Nitrocompostos/toxicidade , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Animais , Afídeos/crescimento & desenvolvimento , Neonicotinoides , Reprodução/efeitos dos fármacos
19.
Inhal Toxicol ; 26(11): 691-6, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25162721

RESUMO

An experiment was conducted to test the hypothesis that a mixture of five inorganic gases could reproduce certain central vascular effects of repeated inhalation exposure of apolipoprotein E-deficient mice to diesel or gasoline engine exhaust. The hypothesis resulted from preceding multiple additive regression tree (MART) analysis of a composition-concentration-response database of mice exposed by inhalation to the exhausts and other complex mixtures. The five gases were the predictors most important to MART models best fitting the vascular responses. Mice on high-fat diet were exposed 6 h/d, 7 d/week for 50 d to clean air or a mixture containing 30.6 ppm CO, 20.5 ppm NO, 1.4 ppm NO2, 0.5 ppm SO2, and 2.0 ppm NH3 in air. The gas concentrations were below the maxima in the preceding studies but in the range of those in exhaust exposure levels that caused significant effects. Five indicators of stress and pro-atherosclerotic responses were measured in aortic tissue. The exposure increased all five response indicators, with the magnitude of effect and statistical significance varying among the indicators and depending on inclusion or exclusion of an apparent outlying control. With the outlier excluded, three responses approximated predicted values and two fell below predictions. The results generally supported evidence that the five gases drove the effects of exhaust, and thus supported the potential of the MART approach for identifying putative causal components of complex mixtures.


Assuntos
Poluentes Atmosféricos/química , Doenças Cardiovasculares/induzido quimicamente , Gases/química , Gasolina/análise , Emissões de Veículos/análise , Poluentes Atmosféricos/toxicidade , Amônia/química , Amônia/toxicidade , Animais , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Monóxido de Carbono/química , Monóxido de Carbono/toxicidade , Relação Dose-Resposta a Droga , Gases/toxicidade , Camundongos , Camundongos Knockout , Óxido Nítrico/química , Óxido Nítrico/toxicidade , Óxido Nitroso/química , Óxido Nitroso/toxicidade , Óxidos/química , Óxidos/toxicidade , Compostos de Enxofre/química , Compostos de Enxofre/toxicidade , Emissões de Veículos/toxicidade
20.
Crit Rev Toxicol ; 44 Suppl 2: 1-14, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24832550

RESUMO

Plant protection products (PPPs) and the active substance(s) contained within them are rigorously and comprehensively tested prior to registration to ensure that human health is not impacted by their use. In recent years, there has been a widespread drive to have more relevant testing strategies (e.g., ILSI/HESI-ACSA and new EU Directives), which also take account of animal welfare, including the 3R (replacement, refinement, and reduction) principles. The toxicity potential of one such new active substance, sulfoxaflor, a sulfoximine insecticide (CAS #946578-00-3), was evaluated utilizing innovative testing strategies comprising: (1) an integrated testing scheme to optimize information obtained from as few animals as possible (i.e., 3R principles) through modifications of standard protocols, such as enhanced palatability study design, to include molecular endpoints, additional neurotoxicity and immunotoxicity parameters in a subchronic toxicity study, and combining multiple test guidelines into one study protocol; (2) generation of toxicokinetic data across dose levels, sexes, study durations, species, strains and life stages, without using satellite animals, which was a first for PPP development, and (3) addition of prospective mode of action (MoA) endpoints within repeat dose toxicity studies as well as proactive inclusion of specific MoA studies as an integral part of the development program. These novel approaches to generate key data early in the safety evaluation program facilitated informed decision-making on the need for additional studies and contributed to a more relevant human health risk assessment. This supplement also contains papers which describe in more detail the approach taken to establish the MoA and human relevance framework related to toxicities elicited by sulfoxaflor in the mammalian toxicology studies: developmental toxicity in rats mediated via the fetal muscle nicotinic acetylcholine receptor (nAChR) ( Ellis-Hutchings et al. 2014 ); liver tumors in rodents mediated via CAR/PXR ( LeBaron et al. 2014 ); and Leydig cell tumors in Fischer 344 rats ( Rasoulpour et al. 2014 ).


Assuntos
Agroquímicos/toxicidade , Inseticidas/toxicidade , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Testes de Toxicidade/métodos , Bem-Estar do Animal , Animais , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Humanos , Piridinas/farmacocinética , Medição de Risco , Compostos de Enxofre/farmacocinética
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