Identification of volatiles from Pinus silvestris attractive for Monochamus galloprovincialis using a SPME-GC/MS platform

Introduction

A myriad of volatile organic compounds (VOCs) released by terrestrial vegetation plays an important role in environmental sciences. A thorough chemical identification of these species at the molecular level is essential in various fields, ranging from atmospheric chemistry to ecology of forest ecosystems. In particular, the recognition of VOCs profiles in a context of plant?Cinsect communication is a key issue for the development of forest protection tools.

Purpose

This work was aimed at the development of a simple, robust and reliable method for the identification of volatiles emitted from plant materials, which can attract or deter pest insects. Specifically, volatiles emitted from the bark of Pinus sylvestris were studied, which might attract the black pine sawyer beetle Monochamus galloprovincialis??a serious pest of the tree and a vector of a parasitic nematode Bursaphelenchus xylophius.

Method

The volatiles from bark samples were collected using a solid-phase micro-extraction technique, and subsequently analysed by gas-chromatography/mass-spectrometry (GC/MS). The characterisation of the volatile fraction was based on the comparison with data in mass spectral libraries, and in most cases, with the available authentic standards. The identified compounds were screened against the available entomological data to select insect attractors.

Results

The identified components included terpenes (??-pinene, ?-3-carene, and para-cymenene), oxygenated terpenes (??-terpineol and verbenone), sesquiterpenes (??-longipinene, longifolene, E-??-farnesene, ??-cadinene and pentadecane), and diterpenes (manoyl oxide and (+)-pimaral). Of these, longifolene and (+)-pimaral are of particular interest as plausible attractors for the M. galloprovincialis beetle that might find application in the construction of insect bait traps.     

Enzyme activity and microorganisms diversity in soil contaminated with the Boreal 58 WG herbicide

Next-generation herbicides are relatively safe when used properly, but the recommended rates are relatively low, which can lead to overdosing. This study evaluated the responses of soil-dwelling microorganisms and soil enzymes to contamination with the Boreal 58 WG herbicide. The analyzed product contains active ingredients flufenacet and isoxaflutole. All tests were performed under laboratory conditions. The analyzed material was sandy clay. Boreal 58 WG was introduced to soil in four doses. Soil without the addition of the herbicide served as the control. The soil was mixed with the tested herbicide, and its moisture content was maintained at 50% of capillary water capacity. Biochemical and microbiological analyses were performed on experimental days 0, 20, 40, 80 and 160. Accidental contamination of soil with the Boreal 58 WG herbicide led to a relatively minor imbalance in the soil microbiological and biochemical profile. The herbicide dose influenced dehydrogenase activity in only 0.84%, urease activity in 2.04%, β-glucosidase activity in 8.26%, catalase activity in 12.40%, arylsulfatase activity in 12.54%, acid phosphatase activity in 42.11%, numbers of organotrophic bacteria in 18.29%, actinomyces counts in 1.31% and fungi counts in 6.86%.     

The biochemical activity of soil contaminated with fungicides

Excess fungicides can pose a serious threat to the soil environment. Fungicides can lower the microbiological and biochemical activity of soil and lead to yield declines. Soils contaminated with fungicides have to be remediated to maintain the optimal function of soil ecosystems. This study evaluates the effect of neutralizing substances on soil enzymatic activity and the yield of Triticum aestivum L. in soil contaminated with fungicides. Sandy loam (Eutric Cambisols) with pH_KCl 7.0 was contaminated with an aqueous solution of Amistar 250 SC and Falcon 460 EC in the following doses: 0 (soil without fungicide – treated as a control), RD (dose recommended by the manufacturer) and 300?×?RD (dose 300-fold higher than the recommended dose). Soil was supplemented with bentonite and basalt meal at a dose of 10?g kg^?1 DM of soil (dry mass of soil). The fungicide dose recommended by the manufacturer did not induce changes in soil enzymatic activity or the yield of T. aestivum L. Our findings indicate that the tested fungicides can be safely applied to protect crops against fungal pathogens. However, when applied at the dose of 300?×?RD, the tested fungicides strongly inhibited soil enzymatic activity and disrupted the growth and development of spring wheat. Soil supplementation with bentonite and basalt meal improved the yield of T. aestivum L., and bentonite was more effective in reducing fungicide stress. The analyzed substances were not highly effective in restoring biochemical homeostasis in soil.     

Comparison of annual dry and wet deposition fluxes of selected pesticides in Strasbourg, France

This work summarizes the results of a study of atmospheric wet and dry deposition fluxes of Deisopropyl-atrazine (DEA), Desethyl-atrazine (DET), Atrazine, Terbuthylazine, Alachlor, Metolachlor, Diflufenican, Fenoxaprop-p-ethyl, Iprodione, Isoproturon and Cymoxanil pesticides conducted in Strasbourg, France, from August 2000 through August 2001. The primary objective of this work was to calculate the total atmospheric pesticide deposition fluxes induced by atmospheric particles. To do this, a modified one-dimensional cloud water deposition model was used. All precipitation and deposition samples were collected at an urban forested park environment setting away from any direct point pesticide sources. The obtained deposition fluxes induced by atmospheric particles over a forested area showed that the dry deposition flux strongly contributes to the total deposition flux. The dry particle deposition fluxes are shown to contribute from 4% (DET) to 60% (cymoxanil) to the total deposition flux (wet + dry).     

Implication of zinc excess on soil health

This study was undertaken to evaluate zinc's influence on the resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease. The experiment was conducted in a greenhouse of the University of Warmia and Mazury (UWM) in Olsztyn, Poland. Plastic pots were filled with 3 kg of sandy loam with pH_KCl – 7.0 each. The experimental variables were: zinc applied to soil at six doses: 100, 300, 600, 1,200, 2,400 and 4,800 mg of Zn²⁺ kg^?1 in the form of ZnCl₂ (zinc chloride), and species of plant: oat (Avena sativa L.) cv. Chwat and white mustard (Sinapis alba) cv. Rota. Soil without the addition of zinc served as the control. During the growing season, soil samples were subjected to microbiological analyses on experimental days 25 and 50 to determine the abundance of organotrophic bacteria, actinomyces and fungi, and the activity of dehydrogenases, catalase and urease, which provided a basis for determining the soil resistance index (RS). The physicochemical properties of soil were determined after harvest. The results of this study indicate that excessive concentrations of zinc have an adverse impact on microbial growth and the activity of soil enzymes. The resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease decreased with an increase in the degree of soil contamination with zinc. Dehydrogenases were most sensitive and urease was least sensitive to soil contamination with zinc. Zinc also exerted an adverse influence on the physicochemical properties of soil and plant development. The growth of oat and white mustard plants was almost completely inhibited in response to the highest zinc doses of 2,400 and 4,800 mg Zn²⁺ kg^?1.     

Effect of chemophytostabilization practices on arbuscular mycorrhiza colonization of Deschampsia cespitosa ecotype Waryński at different soil depths

The effects of chemophytostabilization practices on arbuscular mycorrhiza (AM) of Deschampsia cespitosa roots at different depths in soils highly contaminated with heavy metals were studied in field trials. Mycorrhizal parameters, including frequency of mycorrhization, intensity of root cortex colonization and arbuscule abundance were studied. Correlations between concentration of bioavailable Cd, Zn, Pb and Cu in soil and mycorrhizal parameters were estimated. An increase in AM colonization with increasing soil depth was observed in soils with spontaneously growing D. cespitosa. A positive effect of chemophytostabilization amendments (calcium phosphate, lignite) on AM colonization was found in the soil layers to which the amendments were applied. Negative correlation coefficients between mycorrhizal parameters and concentration of bioavailable Cd and Zn in soil were obtained. Our results demonstrated that chemophytostabilization practices enhance AM colonization in D. cespitosa roots, even in soils fertilized with high rates of phosphorus.     

Human health risk assessment case study: an abandoned metal smelter site in Poland

United States Environmental Protection Agency methodologies for human health risk assessment (HRA) were applied in a Brownfields Demonstration Project on the Warynski smelter site (WSS), an abandoned industrial site at Piekary Slaskie town, Upper Silesia, Poland. The HRA included the baseline risk assessment (BRA) and the development of risk-based preliminary remedial goals (RBPRGs). The HRA focused on surface area covered with waste materials, which were evaluated with regard to the potential risks they may pose to humans. Cadmium, copper, iron, manganese, lead, and zinc were proposed as the contaminants of potential concern (COPCs) at WSS based on archive data on chemical composition of waste located on WSS. For the defined future land use patterns, the industrial (I) and recreational (II) exposure scenarios were assumed and evaluated. The combined hazard index for all COPCs was 3.1E+00 for Scenario I and 3.2E+00 for Scenario II. Regarding potential carcinogenic risks associated with the inhalation route, only cadmium was a contributor, with risks of 1.6E-06 and 2.6E-07 for Scenario I and Scenario II, respectively. The results of the BRA indicated that the potential health risks at WSS were mainly associated with waste material exposure to cadmium (industrial and recreational scenarios) and lead (industrial scenario). RBPRGs calculated under the industrial scenario were 1.17E+03 and 1.62E+03 mg/kg for cadmium and lead, respectively. The RBPRG for cadmium was 1.18E+03 mg/kg under the recreational scenario. The BRA results, as well as RBCs, are comparable for both scenarios, so it is impossible to prioritize land use patterns for WSS based on these results. For choosing a future land use pattern or an appropriate redevelopment option, different factors would be decisive in the decision-making process, e.g., social, market needs, technical feasibility and costs of redevelopment actions or acceptance of local community.     

Effect of a mixture of flufenacet and isoxaflutole on population numbers of soil-dwelling microorganisms,enzymatic activity of soil,and maize yield

Abstract

This study was aimed to evaluate the effect of a mixture of flufenacet?+?isoxaflutole on counts of microorganisms, ecophysiological diversity index (EP), colony development index (CD) and on the enzymatic activity of soil and maize growth. The experiment was conducted with sandy clay, to which the tested herbicide was administered in doses of: 0.25, 5.0, 10, 20, 40, 80 and 160?mg/kg. Soil without the addition of the mixture served as the control. Results demonstrated that the tested mixture contributed to a decrease in numbers of Azotobacter, organotrophic bacteria, actinobacteria and fungi. The negative effect of the herbicide could also be noticed in the case of the enzymatic activity of soil. Soil contamination contributed to suppressed activities of dehydrogenases, catalase, urease, alkaline phosphatase and arylsulfatase. In turn, the initial increase in the activity of β-glucosidase was followed by its decline observed with time. The flufenacet?+?isoxaflutole mixture affected also maize plant growth, reducing maize dry matter yield when used at doses from 5.0 to 160?mg/kg. In summary, it may be concluded that mixture evokes a negative effect on the microbiological and biochemical activity of soil and that their excess in the soil leads to plant decay as at the seeding stage.     

Application of HS-SPME in the determination of potentially toxic organic compounds emitted from resin-based dental materials

Leaching of volatile substances from resin-based dental materials may have a potential impact on the biocompatibility as well as safety of these materials. Information from manufacturers on ingredients in the materials is very often incomplete. Patients and dentists may be in contact with components emitted from cured dental fillings or from substrates applied in their preparation. Therefore, determination of the components of these materials is necessary for better prevention from possible harmful effects caused by dental fillings. The aim of this work was the isolation and identification of organic compounds evolved from four commercial resin-modified glass-ionomer cements (resin-based dental materials applied in dentistry) by using an alternative method of volatile compounds analysis-HS-SPME (headspace-solid phase microextraction). Dental materials were heated in closed vial at various temperatures and volatile substances released into the headspace phase above the sample were isolated on a thin polymeric fibre placed in SPME syringe. Identification was performed by using the GC-MS (gas chromatography-mass spectrometry) technique. Almost 50 RMGIC (resin-modified glass-ionomer cement) components (monomers and additives) were identified. The main identified leachables were: iodobenzene (DPICls-diphenyliodonium chloride degradation product), camphorquinone (photo-initiator), tert-butyl-p-hydroxyanisole (inhibitor), 4-(dimethylamino)ethyl benzoate (co-initiator), ethylene glycol dimethacrylate (monomer).