Longitudinal air permeability of pinewood with beetle transmitted blue-stain

The mountain pine beetle epidemic is destroying an extensive volume of the lodgepole pine forests being one of the most commercially harvested trees in British Columbia. The purpose of this study was to test the permeability of wood of four different classes regarding the time of the beetle attack. The experiments used the ‘‘falling water’’ unsteady-steady method of measuring superficial air permeability. The results showed that the specific permeability is not significantly different between the infested classes tested. The same conclusion could be reached for comparisons of uninfected and infested wood.     

Bleaching treatments for blue-stained lodgepole pine affected by the mountain pine beetle <Emphasis Type="Italic">Dendroctonus ponderosae</Emphasis>

Zusammenfassung Over 400 million  m³ of standing lodgepole pine timber in the forests of British Columbia, Canada, is affected by the mountain pine beetle and associated ophiostomatoid fungi that stain the sapwood of infected pine trees a blue-grey color (Lee et al. 2005). Such staining is undesirable in appearance grade wood products and some grades of structural timber, and a simple method of removing the stain or reducing its severity is required. This study screened a range of bleaching agents to determine which ones were most effective at removing the blue stain and then optimised treatment parameters for the most efficient bleaching agent (sodium hypochlorite).     

Bleaching treatments for blue-stained lodgepole pine affected by the mountain pine beetle Dendroctonus ponderosae

Over 400 million  m³ of standing lodgepole pine timber in the forests of British Columbia, Canada, is affected by the mountain pine beetle and associated ophiostomatoid fungi that stain the sapwood of infected pine trees a blue-grey color (Lee et al. 2005). Such staining is undesirable in appearance grade wood products and some grades of structural timber, and a simple method of removing the stain or reducing its severity is required. This study screened a range of bleaching agents to determine which ones were most effective at removing the blue stain and then optimised treatment parameters for the most efficient bleaching agent (sodium hypochlorite).     

The influence of Rhyzopertha dominica (F.) on the technological quality of cereal grains treated with diatomaceous earth

Laboratory bioassays (temperature 26 ± 1 °C and 60 ± 5% r. h.) were performed to evaluate the insecticidal effect of three different diatomaceous earths (DE) against Rhyzopertha dominica (F.) in wheat, triticale and rye. In order to achieve this, the amount of damaged kernels, amount of debris, wet gluten content, gluten index and rheological properties were assessed in infested samples, infested samples treated with DE Protect-It and two DEs originating from Serbia (S-1 and S-2) and were compared to control (uninfested) samples using Chopin Mixolab. The most susceptible to beetle infestation were rye sample and wheat variety Planeta. The lowest weight of damaged grain was found after applying DE Protect-It to all grain types. The amount of damaged kernels, the amount of debris and loss of mass were the highestin sample treated with DE S-2. While infestation resulted in increase in the amount of damaged kernels and debris and decrease in wet gluten content, and provoked weakening of gluten network structure as well as starch damage, an addition of DE, especially Protect-It, resulted in grain samples of similar technological quality to control (uninfested) sample. The susceptibility of different cereals used in breadmaking to infestation by R. dominica, as well as their response to the insecticidal effect of diatomaceous earth largely varied. Both cereal type and quality, as measured by wet gluten content and gluten index, influenced grain response to infestation. Insecticidal effect of diatomaceous earth, especially DE S-1and DE S-2, was the least effective in terms of triticale. These findings suggest that the application of DE in cereals storage management might largely be affected with grain type as well as grain composition and technological quality.     

The effect of different dietary treatments on volatile organic compounds and aromatic characteristics of buffalo Mozzarella cheese

The objective of this study was to evaluate the effect of two dietary treatments, ryegrass hay (RH) and wrapped ryegrass silage (WRS) on the volatile organic compounds (VOCs) of buffalo Mozzarella cheese. The primary data were collected from 40 female buffaloes. Twenty animals were fed RH, and other twenty received WRS. Volatile organic compounds were identified using a mass selective detector after extraction with a ‘purge and trap’ system and a gas chromatographic analysis. Our results showed differences in the aromatic profile of Mozzarella cheese samples obtained from buffaloes receiving different feed. In particular, 5 VOCs allowed the discrimination between cheese samples.     

Mineral content of insect infested stored legumes treated with edible oils

Mineral content of three insect (pulse beetle, Callosobruchus chinensis L.) infested legumes viz. chick pea, mung pea and pigeon pea stored for six months and treated with three edible oils viz. groundnut, mustard and coconut oil has been studied. With increase in storage period significant increase in calcium, phosphorus and iron content of untreated legumes was observed. After three months of storage slight increase in three minerals was observed in the legumes treated with coconut oil which continued till the end of sixth months as compared to other two oil treated counterparts. The storage period was associated with insect infestation which in turn influenced the mineral content of legumes. Ground nut and mustard oils were able to protect legumes for six months against insect infestation when applied in small amounts (0.5%). Whereas coconut oil had protective effect against insect infestation for four months only.     

A comparison of emissions from vehicles fueled with diesel or compressed natural gas

A comprehensive comparison of emissions from vehicles fueled with diesel or compressed natural gas (CNG) was developed from 25 reports on transit buses, school buses, refuse trucks, and passenger cars. Emissions for most compounds were highest for untreated exhaust emissions and lowest for treated exhaust CNG buses without after-treatment had the highest emissions of carbon monoxide, hydrocarbons, nonmethane hydrocarbons (NMHC), volatile organic compounds (VOCs; e.g., benzene, butadiene, ethylene, etc.), and carbonyl compounds (e.g., formaldehyde, acetaldehyde, acrolein). Diesel buses without after-treatment had the highest emissions of particulate matter and polycyclic aromatic hydrocarbons (PAHs). Exhaust after-treatments reduced most emissions to similar levels in diesel and CNG buses. Nitrogen oxides (NO(x)) and carbon dioxide (CO2) emissions were similar for most vehicle types, fuels, and exhaust after-treatments with some exceptions. Diesel school buses had higher CO2 emissions than the CNG bus. CNG transit buses and passenger cars equipped with three-way catalysts had lower NO(x) emissions. Diesel buses equipped with traps had higher nitrogen dioxide emissions. Fuel economy was best in the diesel buses not equipped with exhaust after-treatment.     

Source apportionment of ambient volatile organic compounds in Beijing

The ambient air quality standard for ozone is frequently exceeded in Beijing in summer and autumn. Source apportionments of volatile organic compounds (VOCs), which are precursors of ground-level ozone formation, can be helpful to the further study of tropospheric ozone formation. In this study, ambient concentrations of VOCs were continuously measured with a time resolution of 30 min in August 2005 in Beijing. By using positive matrix factorization (PMF), eight sources for the selected VOC species were extracted. Gasoline-related emissions (the combination of gasoline exhaust and gas vapor), petrochemicals, and liquefied petroleum gas (LPG) contributed 52, 20, and 11%, respectively, to total ambient VOCs. VOC emissions from natural gas (5%), painting (5%), diesel vehicles (3%), and biogenic emissions (2%) were also identified. The gasoline-related, petrochemical, and biogenic sources were estimated to be the major contributors to ozone formation potentials in Beijing.     

Dimensional stability of wood–plastic composites reinforced with potassium methyl siliconate modified fiber and sawdust made from beetle-killed trees

Wood from two varieties of beetle-killed trees was used to fabricate wood–plastic composites. Loblolly pine and lodgepole pine beetle-killed trees were defibrated mechanically and thermomechanically, respectively, into fiber. Fiber and sawdust produced from the trees were modified with potassium methyl siliconate (PMS) and injection-molded into fiber/sawdust reinforced plastic composites. Modification of fiber and sawdust with PMS improved the compatibility between lignocellulosic materials and ethylene plastic in the composites, resulting in decreased water sorption, increased dimensional stability, and increased tolerance to morphological variations in the fiber and sawdust. Fiber-to-sawdust ratio and size of sawdust particles affected the time required for saturation with water, as well as dimensional stability.     

Measurement of emissions from air pollution sources. 3. C1-C29 organic compounds from fireplace combustion of wood

Organic compound emission rates for volatile organic compounds (VOC), gas-phase semivolatile organic compounds, and particle-phase organic compounds are measured from residential fireplace combustion of wood. Firewood from a conifer tree (pine) and from two deciduous trees (oak and eucalyptus) is burned to determine organic compound emissions profiles for each wood type including the distribution of the alkanes, alkenes, aromatics, polycyclic aromatic hydrocarbons (PAH), phenol and substituted phenols, guaiacol and substituted guaiacol, syringol and substituted syringols, carbonyls, alkanoic acids, resin acids, and levoglucosan. Levoglucosan is the major constituent in the fine particulate emissions from all three wood types, contributing 18-30% of the fine particulate organic compound emissions. Guaiacol (2-methoxyphenol), and guaiacols with additional substituents at position 4 on the molecule, and resin acids are emitted in significant quantities from pine wood combustion. Syringol (2,6-dimethoxyphenol) and syringols with additional substituents at position 4 on the molecule are emitted in large amounts from oak and eucalyptus firewood combustion, but these compounds are not detected in the emissions from pine wood combustion. Syringol and most of the substituted syringols are found to be semivolatile compounds that are present in both the gas and particle phases, but two substituted syringols that have not been previously quantified in wood smoke emissions, propionylsyringol and butyrylsyringol, are found exclusively in the particle phase and can be used to help trace hardwood smoke particles in the atmosphere. Benzene, ethene, and acetylene are often used as tracers for motor vehicle exhaust in the urban atmosphere. The contribution of wood smoke to the ambient concentrations of benzene, ethene, and acetylene could lead to an overestimate of the contribution of motor vehicle tailpipe exhaust to atmospheric VOC concentrations.     

Semivolatile and volatile organic compound emissions from wood-fired hydronic heaters

Emissions including polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), polyaromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs), were sampled from different wood-fired hydronic heater (HH) technologies. Four commercially available HH technologies were studied: a single-stage conventional combustor with natural updraft, a three-stage downdraft combustion system, a bottom-fed pellet burner, and a two-stage heater with both a combustion and gasification chamber. The fuel consisted of three wood types (red oak, white pine, and white ash), one hardwood pellet brand, and one fuel mixture containing 95% red oak and 5% residential refuse by weight. The various HHs and fuel combinations were tested in a realistic homeowner fuel-charging scenario. Differences in emission levels were found between HH technologies and fuel types. PCDD/PCDF emissions ranged from 0.004 to 0.098 ng toxic equivalency/MJ(input) and PAHs from 0.49 to 54 mg/MJ(input). The former was increased by the presence of 5% by weight refuse. The white pine fuel had the highest PAH emission factor, while the bottom fed pellet burner had the lowest. The major VOCs emitted were benzene, acetylene, and propylene. The highest emissions of PAHs, VOCs, and PCDDs/PCDFs were observed with the conventional unit, likely due to the rapid changes in combustion conditions effected by the damper opening and closing.     

Predicting emissions of SVOCs from polymeric materials and their interaction with airborne particles

A model that predicts the emission rate of volatile organic compounds (VOCs) from building materials is extended and used to predict the emission rate of semivolatile organic compounds (SVOCs) from polymeric materials. Reasonable agreement between model predictions and gas-phase di-2-ethylhexyl phthalate (DEHP) concentrations is achieved using data collected in a previous experimental study that measured emissions of DEHP from vinyl flooring in two very different chambers. While emissions of highly volatile VOCs are subject to "internal" control (the material-phase diffusion coefficient), emissions of the very low volatility SVOCs are subject to "external" control (partitioning into the gas phase, the convective mass-transfer coefficient, and adsorption onto interior surfaces). The effect of SVOCs partitioning onto airborne particles is also examined. The DEHP emission rate is increased when the gas-phase concentration is high, and especially when partitioning to the airborne particles is strong. Airborne particles may play an important role in inhalation exposure as well as in transporting SVOCs well beyond the source. Although more rigorous validation is needed, the model should help elucidate the mechanisms governing emissions of phthalate plasticizers, brominated flame retardants, biocides, and other SVOCs from a wide range of building materials and consumer products.     

Detection of Tribolium castaneum (Herbst) volatile defensive secretions by solid phase microextraction–capillary gas chromatography (SPME-CGC)

The solid phase microextraction (SPME) technique was used for the collection of the volatile defensive secretions released by Tribolium castaneum (Herbst), the red flour beetle. The detection of the major components methyl-1,4-benzoquinone (MBQ) and ethyl-1,4-benzoquinone (EBQ), together with 1-pentadecene (C15:1), was performed by capillary gas chromatography (CGC). SPME samples were identified by CGC coupled to mass spectrometry (MS). Volatile organic compounds (VOC) released from insects were compared employing different SPME fibers. The relative amounts of the major volatiles collected varied with the fiber coating. Quinones accounted for 75% of the volatiles trapped by the carboxen/polydimethylsiloxane (CAR/PDMS) fiber, whereas they only represented 45% of the volatiles trapped with the PDMS fiber. The PDMS/divinylbenzene (DVB) coating exhibited intermediate affinity. In a 15-min extraction period, the highest amounts of VOC extracted from disturbed insects with CAR/PDMS were 349±107 ng/beetle of MBQ, 780±290 ng/beetle of EBQ, and 144±69 ng/beetle of C15:1. The total VOC amounts extracted by SPME were estimated by adding the disturb-released VOC to heat-released VOC of the same insects, resulting in 742±93 ng/beetle of MBQ, 1672±244 ng/beetle of EBQ, and 946±237 ng/beetle of C15:1. SPME-CGC is a simple method to detect and estimate T. castaneum volatiles. This method has the potential to detect insect infestation in stored products.     

Arsenic accumulation in bark beetles and forest birds occupying mountain pine beetle infested stands treated with monosodium methanearsonate

The arsenic-based pesticide, monosodium methanearsonate (MSMA), is presently being evaluated for re-registration in Canada and the United States and has been widely used in British Columbia to help suppress Mountain Pine Beetle (MPB) outbreaks. We assessed the availability and exposure of MSMA to woodpeckers and other forest birds that may prey directly on contaminated bark beetles. Total arsenic residues in MPB from MSMA treated trees ranged from 1.3-700.2 microg g(-1) dw (geometric mean 42.0 microg g(-1)) with the metabolite monomethyl arsonic acid (MMAA) contributing 90-97% to the total arsenic extracted. Live adult and larval beetles were collected from treated trees and reached concentrations up to 327 microg g(-1) dw. MPBs from reference trees had significantly lower arsenic concentrations averaging 0.19 microg g(-1) dw. Woodpeckers foraged more heavily on MSMAtreesthat contained beetles with lower arsenic residues, suggesting those trees had reduced MSMAtranslocation and possibly greater live beetle broods. Blood samples from five species of woodpeckers and other forest passerines breeding within 1 km of MSMA stands contained elevated levels of total arsenic but with large individual variability (geometric mean = 0.18 microg g(-1) dw, range 0.02-2.20 microg g(-1). The results indicate that there is significant accumulation and transfer of organic arsenic within the food chain at levels that may present a toxicity risk to avian wildlife.     

Efficacy of quarantine treatments using reduced methyl bromide concentrations to disinfest Pinus radiata logs from New Zealand

We report here the results of three successive toxicity studies against a selection of forest insect pests, conducted in New Zealand to determine the efficacy of reduced methyl bromide (MB) rates, i.e. rates lower than those currently used, to disinfest export pine logs. First, the relative tolerance to MB among the naked life stages of the golden-haired bark beetle, Hylurgus ligniperda, the black pine bark beetle, Hylastes ater (Coleoptera: Curculionidae) and burnt pine longhorn beetle, Arhopalus ferus (Coleoptera: Cerambycidae) was determined in the laboratory. Then, the most MB-tolerant species and life stage(s) in pine logs was subjected to selected fumigation schedules using reduced concentrations of MB. Finally, the results of the laboratory studies were validated under commercial conditions at the Port of Tauranga, New Zealand, using logs infested with the most tolerant life stage, and log stacks. Our results indicated that either 30 g/m³ MB at >15 °C or 40 g/m³ MB at ≤ 15 °C for 16 h would ensure quarantine security against forest insects in New Zealand export logs. These reduced MB concentrations are approximately 70% and 65%, respectively, lower than 80 g/m³ at >15 °C or 120 g/m³ at ≤15 °C. If implemented by regulatory agencies and accepted by trading partners, these concentrations will provide significant environmental and economic benefits to the New Zealand forest industry and will pave the way for other countries to implement similar approaches to reduce MB usage in accordance to the Montreal Protocol.     

Detection of External and Internal Insect Infestation in Wheat by Near-Infrared Reflectance Spectroscopy

Near-infrared spectroscopy (NIR) in the reflectance mode was investigated for the rapid, automatic and non-destructive detection of insect stored-grain pests external or internal to wheat kernels. Convincing calibration performance was obtained for external adult Oryzaephilus surinamensis (L) (saw-toothed grain beetle) in unmilled samples including varieties Beaver (soft wheat) and Mercia (hard wheat) at two moisture contents. With this large substrate variability, the method could differentiate between uninfested samples and samples with approximately 270 insects kg⁻¹ or more. Milling made no improvement. Large spectral differences were observed between uninfested kernels and kernels infested internally with Sitophilus granarius (L) (grain weevil) larvae or pupae, arising from both a changed chemical composition and physical structure. Single uninfested and infested kernels were discriminated by their second derivative (d²) spectra. For both external and internal infestation there was substantial evidence that insect protein and/or chitin and moisture were being detected. NIR should be useful as a rapid method of detection.     

FRUIT QUALITY OF COLD STORED SWEET CHERRIES INFESTED WITH CODLING MOTH

The effect of codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), infestation on the quality of sweet cherry, Prunus avium (L.) L., fruit was studied. Each cherry was infested with one first instar codling moth and held at 3.3C for 0 (control), 1, 2, 4, 7, 10, or 14 days. After cold storage, fruits were maintained at 25C and observed periodically for damage using a visual scale from 0 as no damage, to 9 as complete destruction. Two groups of ‘Bing’ cherries were examined, one from an organically grown orchard and the other from a commercial orchard with conventional chemical control. Uninfested fruits maintained quality for one month at 25C whereas infested fruits had a damage rating of 2 by the fifth day. Infested organic fruits deteriorated faster than the conventional cherries. Larvae were often not detected because of fruit deterioration and fungal contamination. Fruit quality deterioration due to codling moth infestation is an important component of the Systems Approach for quarantine security for cherries exported to Japan. Infested fruit would rapidly deteriorate as the result of decay and be culled at time of packing.     

吹扫捕集-气质联用法测定天然饮用水中挥发性有机物

采用吹扫捕集-气相色谱/质谱联用法,测定天然饮用水中35种挥发性有机化合物,包括三卤甲烷、卤代苯类、苯系物以及多环芳烃类等。方法检出限范围为0.05～0.17μg/L,35种有机物加标5μg/L测定回收率为86.5%～113%,RSD(n=6)为1.6%～6.1%。调研了市售的44个瓶装天然饮用水和5个水源水样品:瓶装天然饮用水中检出1,2-二氯乙烷、一氯二溴甲烷、二氯一溴甲烷、三溴甲烷、苯、三氯甲烷、1,2,4-三甲苯、甲苯共8个化合物,其中三氯甲烷的检出率达到49%,但检测结果均在相关标准的限量要求范围内;水源水样品中均未测得挥发性有机化合物。     

包装印刷有机废气排放控制与治理研究

从包装印刷行业有机物废气污染现状和治理重要性角度出发,结合行业有机废气排放控制标准。重点介绍了企业合理选址。有机溶剂挥发浓度控制。环保油墨应用以及高效干燥固化工艺等废气排放控制技术和热力氧化法、吸附法、等离子体氧化分解法以及膜分离法等有机废气末端治理实用技术。进而归纳总结了行业内有机废气排放控制与治理所面临的挑战。     

Philosophy of forest insect control in Britain

It is concluded that, on economic grounds, prevention of infestation by amelioration of the site and improvement in the vigour of the trees is more likely to be practical than remedial spraying of infested trees.