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The effect of relative humidity on swine vesicular disease virus in dried films before and during formaldehyde fumigation.

Swine Vesicular Disease virus (SVDV) did not survive drying at high relative humidities (r.h.) but there was little virus loss at low r.h. Purified virus dried in films was inactivated by formaldehyde fumigation only at high r.h. Inactivation was also influenced by the suspending medium from which the virus was dried. Purified virus resuspended in distilled water and then dried, was rapidly killed, but that in tissue culture fluid survived.

Animals↗

Bioreactors for removing methyl bromide following contained fumigations.

Use of methyl bromide (MeBr) as a quarantine, commodity, or structural fumigant is under scrutiny because its release to the atmosphere contributes to the depletion of stratospheric ozone. A closed-system bioreactor consisting of 0.5 L of a growing culture of a previously described bacterium, strain IMB-1, removed MeBr (> 110 micromol L(-1)) from recirculating air. Strain IMB-1 grew slowly to high cell densities in the bioreactor using MeBr as its sole carbon and energy source. Bacterial oxidation of MeBr produced CO2 and hydrobromic acid (HBr), which required continuous neutralization with NaOH for the system to operate effectively. Strain IMB-1 was capable of sustained oxidation of large amounts of MeBr (170 mmol in 46 d). In an open-system bioreactor (10-L fermenter), strain IMB-1 oxidized a continuous supply of MeBr (220 /micromol L(-1) in air). Growth was continuous, and 0.5 mol of MeBr was removed from the air supply in 14 d. The specific rate of MeBr oxidation was 7 x 10(-16) mol cell(-1) h(-1). Bioreactors such as these can therefore be used to remove large quantities of contaminant MeBr, which opens the possibility of biodegradation as a practical means for its disposal.

Air Pollution↗

QSAR evaluation of cyanohydrins' fumigation toxicity to house fly (Musca domestica) and lesser grain borer (Rhyzopertha dominica).

Using fumigation toxicity data of 11 natural and synthetic cyanohydrins to house fly (Musca domestica) and a stored-product pest, the lesser grain borer (Rhyzopertha dominica), the quantitative structure-activity relationships (QSAR) of cyanohydrins were examined by Oxford Molecular CAChe 3.2 and Microsoft Excel. This analysis used eight physicochemical parameters. Correlation between the LC(50) values for house fly and lesser grain borers was also evaluated. The results showed that log P, polarizability, and molar refractivity are the best descriptors to explain the relationship between the structure of cyanohydrins and biological effects in house flies, and to a lesser degree in lesser grain borers. A significant relationship was also found between the toxicity to house flies and lesser grain borers.

Animals↗

Changes in the community of ectomycorrhizal fungi and increased fine root number under adult beech trees chronically fumigated with double ambient ozone concentration.

Forest soils are an important but under-studied part of forest ecosystems. The effects of O(3) on below-ground processes in a mature forest have only received limited attention so far. In our study, we have analysed the community of ectomycorrhizal fungi and beech fine root dynamics over two growing seasons (2003 - 2004) in a 70-year old mixed spruce-beech forest stand, in which two groups of five adult beech trees were either fumigated by 2 x ambient ozone concentration or used as control. The main difference between previous studies and our approach was that previous studies were performed on seedlings in pot experiments or in closed or open top chambers, and not IN SITU, in a mature forest stand. Although beech is a relatively unresponsive species to tropospheric O(3), we found a pronounced effect of 2 x O(3) on the number of vital ectomycorrhizal root tips and non-turgescent fine roots. Both categories of roots were significantly increased when compared to controls in two consecutive years at each sampling event. The number of types of ectomycorrhizae and species richness increased in 2004, but not in the extremely dry year 2003. We hypothesised that the observed changes might be an expression of a transitional state in below-ground succession of niches caused by an O(3) induced effect on carbon allocation to roots and the rhizosphere. We have detected changes in ectomycorrhizal species level, however Shannon-Weavers species diversity index and percentage of types of ectomycorrhizae did not change significantly in any sampling year thus indicating our results cannot be unequivocally explained by summer drought in year 2003 or by O(3) exposure alone.

Fagus↗

Personal and environmental air sampling of methyl bromide during experimental greenhouse fumigation.

In this investigation methyl bromide, a widely used soil fumigant, was investigated with respect to workers exposure and environmental fortification at the greenhouses of Thessaloniki area, Northern Greece. By means of personal and environmental air sampling through charcoal, methyl bromide concentration was measured by gas chromatography using a capillary OV-1 column at 45 degrees C and flame ionization detector (FID). Personal air sampling for two workers showed that the levels of exposure to methyl bromide were 89 and 92 mg/m3 respectively. These values exceeded the safety limits. The mean maximum and mean minimum concentrations in the environmental air samples inside the greenhouse, for 8 hours duration, were 142 mg/m3 and 4 mg/m3, respectively. These concentrations were determined within four and eleven days after the application of methyl bromide.

Adsorption↗

Methyl bromide intoxication during grain store fumigation.

There have been over 300 cases of methyl bromide poisoning reported in the literature. The first objective of this case report was to bring out an experience with the false belief that work in a closed space is safe when accompanied by the use of a cartridge respirator with activated charcoal. The second objective of this article was to demonstrate the marked toxicity of methyl bromide with the potential to cause long-term neurological damage. Two experienced fumigation workers (equipped with rapidly saturable respiratory cartridges) entered a building where the concentration of methyl bromide was 17g x m-3 instead of the advised 20mg x m-3. They felt rapidly unwell and complained of nausea and shortness of breath, followed for one them by generalized convulsions. Five months later this last man was still bedridden. The other worker had almost no after-effects. The highest bromide level was found in the blood and also in the activated charcoal cartridge of the most injured worker. There was a relationship between methyl bromide level exposure and neurological damage importance.

Adult↗

Rapid uptake, metabolism, and elimination of inhaled sulfuryl fluoride fumigant by rats.

Sulfuryl fluoride (SO(2)F(2)) is a structural fumigant gas used to control drywood termites and wood-boring beetles. The pharmacokinetics and metabolism of inhaled SO(2)F(2) were evaluated in male Fischer-344 rats exposed to 30 or 300 ppm (35)S-labeled SO(2)F(2) for 4 h. Blood, urine and feces were collected during and after the exposures and analyzed for radioactivity, (35)S-labeled fluorosulfate and sulfate, and fluoride (urine and feces only). Selected tissues were collected 7 days post-exposure and analyzed for radioactivity. During and after unlabeled SO(2)F(2) exposures, blood, brain, and kidney were collected and analyzed for fluoride ion. SO(2)F(2) was rapidly absorbed, achieving maximum concentrations of radioactivity in both plasma and red blood cells (RBC) near the end of the 4-h exposure period. Radioactivity was rapidly excreted, mostly via the urine. Seven days post-exposure, small amounts of radioactivity were distributed among several tissues, with the highest concentration detected in respiratory tissues. Radioactivity associated with the RBC remained elevated 7 days post-exposure, and highly perfused tissues had higher levels of radioactivity than other non-respiratory tissues. Radioactivity cleared from plasma and RBC with initial half-lives of 2.5 h after 30 ppm and 1-2.5 h after 300 ppm exposures. The terminal half-life of radioactivity was 2.5-fold longer in RBC than plasma. Based on the radiochemical profiles, there was no evidence of parent (35)SO(2)F(2) in blood. Identification of fluorosulfate and sulfate in blood and urine suggests that SO(2)F(2) is hydrolyzed to fluorosulfate, with release of fluoride, followed by further hydrolysis to sulfate and release of the remaining fluoride.

Administration, Inhalation↗

A study of conventional formaldehyde fumigation methods.

The currently recommended methods for the formaldehyde fumigation of rooms have been studied with the aid of an instrument designed to monitor the temperature, humidity and formaldehyde concentration. The results show that although the procedures are generally effective as measured by microbiological methods the conditions within the areas treated are not those expected from calculations based on the room volume and the amount of formaldehyde used. The measured formaldehyde levels in particular are much lower than predicted and indicate that formaldehyde vapour may be effective at lower concentrations than previously supposed.

Bacillus↗

Occupational dermatosis due to a soil fumigant.

D-D mixture is a preplant soil fumigant. It contains dichloropropanes and dichloropropenes, epichlorohydrin and is known as a primary irritant. Three cases of untoward reaction to D-D are reported. By patch testing, the existence of a contact allergic sensitivity to D-D could be proved in one patient. The other two cases reacted negatively; they were probably of a primary irritant origin. Patch tests with compounds related to D-D suggest that the cause of contact allergy must be sought in the propene(s) fraction of D-D. In future cases of untoward reactions to D-D, patch testing appears to be necessary in order to differentiate between a contact allergic and a primary irritant reaction.

Antinematodal Agents↗

Strain IMB-1, a novel bacterium for the removal of methyl bromide in fumigated agricultural soils.

A facultatively methylotrophic bacterium, strain IMB-1, that has been isolated from agricultural soil grows on methyl bromide (MeBr), methyl iodide, methyl chloride, and methylated amines, as well as on glucose, pyruvate, or acetate. Phylogenetic analysis of its 16S rRNA gene sequence indicates that strain IMB-1 classes in the alpha subgroup of the class Proteobacteria and is closely related to members of the genus Rhizobium. The ability of strain IMB-1 to oxidize MeBr to CO2 is constitutive in cells regardless of the growth substrate. Addition of cell suspensions of strain IMB-1 to soils greatly accelerates the oxidation of MeBr, as does pretreatment of soils with low concentrations of methyl iodide. These results suggest that soil treatment strategies can be devised whereby bacteria can effectively consume MeBr during field fumigations, which would diminish or eliminate the outward flux of MeBr to the atmosphere.

Biodegradation, Environmental↗

Potential hazards of fumigant residues.

A spectrum of fumigants (primarily ethylene dibromide, 1,2-dibromo-3-chloropropane, ethylene oxide, symdibromotetetrachloroethane, 1,3-dichloropropene, dichlorovos, carbon tetrachloride, methyl bromide) as well as their degradation products in foodstuffs and soil have been examined mainly in regard to the potential mutagenicity of their residues.

Alkylating Agents↗

Potential of temperature, controlled atmospheres, and ozone fumigation to control thrips and mealybugs on ornamental plants for export.

Ozone (O3) fumigation is a potential quarantine treatment alternative for controlling stored-product pests and surface insect pests on fresh agricultural commodities. We explored the effects of temperature, treatment time, controlled atmospheres, and vacuum in combination with O3 to control two important pests of ornamental crops: western flower thrips, Frankliniella occidentalis (Pergande), and longtailed mealybug, Pseudococcus longispinus Targioni Tozzetti. Treatment parameters tested were O3 concentrations from 0 to 3,800 ppm, treatment durations were from 30 to 120 min, vacuums were from 0 to 0.41 bar below ambient, temperatures were from 32.2 to 40.6 degrees C, and controlled atmospheres were composed primarily of nitrogen, carbon dioxide, or breathing air [BA]. Treatment efficacy was enhanced by higher O3 concentration and temperature, lower oxygen, and longer treatment times. Reduced pressure was not an important factor. Mealybugs were more difficult to kill than thrips. A 30-min treatment of O3 at approximately 200 ppm in 100% CO2 at 37.8 degrees C killed 47.9 and 98.0% of mealybugs and adult female thrips, respectively. All of the ornamentals tested were damaged to some degree by O3 treatments. However, crops with thick leaves such as orchids exhibited little damage, and the waxy portions of certain flowers were not damaged. The results suggest that O3 has potential as a quarantine treatment to control thrips and mealybugs on selected commodities.

Animals↗

Fumigant activity of plant essential oils and components from Schizonepeta tenuifolia against Lycoriella ingenua (Diptera: Sciaridae).

Plant essential oils from 21 plant species were tested for their insecticidal activities against larvae of Lycoriella ingenua Dufour (Diptera: Sciaridae) by using a fumigation bioassay. Good insecticidal activity against larvae of L. ingenua was achieved with essential oils of Acorus gramineus Solander, Schizonepeta tenuifolia Briquet, and Zanthoxylum piperitum De Candolle at 25 microg/ml air. S. tenuifolia oil showed the most potent insecticidal activity among the plant essential oils. At 12.5 microg/ml air concentration, S. tenuifolia oil caused 96.6% mortality, but mortality decreased to 60% at 3.125 microg/ml air. Analysis by gas chromatography-mass spectrometry led to identification of three major compounds from S. tenuifolia oil. These three compounds were tested individually for their insecticidal activities against larvae of L. ingenua and compared with the toxicity of dichlorvos. Pulegone was the most toxic, followed by menthone and limonene with LC50 values of 1.21, 6.03, and 15.42 microg/ml, respectively. LC50 of dichlorvos was 8.13 microg/ml. Effects of S. tenuifolia and its components on growth of Pleurotus ostreatus (Jacq. ex Fr.) Kummer also were investigated.

Animals↗

Effect of Japanese mint (Mentha arvensis) oil as fumigant on stored sorghum: physical characteristics, sensory quality and germination.

The Japanese mint (Mentha arvensis) oil (JMO) was effective as fumigant against Sitophilus oryzae in sorghum (Sorghum bicolor). The observations on the effect of JMO treatment at a dose of 166.6 microliters/l of space to grains stored for 3 months in desiccators at 28 +/- 5 degrees C showed non significant (P approximately 0.05) effect on grain hardness, grain density and per cent water absorption. The cooking quality evaluated in terms of cooking time required for boiling of grains was also not significantly affected. The JMO treated samples of boiled sorghum scored significantly lower values for sensory quality characteristics viz. taste, aroma and overall acceptability compared to untreated samples. No effect of JMO on seed germination was observed. As sensory quality is lowered by use of JMO, the technique can only be recommended for seed sorghum preservation, not food.

Edible Grain↗

National emission standards for hazardous air pollutants for ethylene oxide commercial sterilization and fumigation operations--EPA. Interim final rule.

Today's action suspends the National Emission Standards for Hazardous Air Pollutants for Ethylene Oxide Commercial Sterilization and Fumigation Operations (EO NESHAP) requirements for chamber exhaust and aeration room vents. The suspension allows affected sources subject to the EO NESHAP to defer compliance with the NESHAP requirements for chamber exhaust and aeration room vents for one year until December 6, 1999. This suspension does not affect the requirement for sources subject to the EO NESHAP to comply with provisions for sterilizer vents by December 6, 1998. This action does not change the level of the standards or the intent of the NESHAP promulgated in 1994.

Central Supply, Hospital↗

[Fumigation of soil and food: assessment of occupational exposure to methyl bromide].

Innovative procedures were developed for the biological monitoring of workers exposed to methyl bromide, through the determination of biomarkers of exposure, such as bromide in serum, and of biomarkers of the biologically effective dose, such as haemoglobin adducts. The effectiveness of the developed techniques for the biological monitoring was tested through the analysis of blood samples from workers employed in soil fumigation.

Agrochemicals↗

Chemical alternatives for soil fumigation with methyl bromide on tobacco seedbeds in nematode and weed control.

The proposed phase out of methyl bromide necessitated the evaluation of a number of chemical alternatives to replace it. The recommended rate of application for methyl bromide, 50 g/m2 was evaluated over three years against various rates of 65% 1,3-Dichloropropene mixed with 35% chloropicrin (1,3-D/C-35); a combination of metham sodium and ethylene dibromide (EDB) and 65% 1,3-Dichloropropene (1,3-D) alone. Chloropicrin and 1,3-D have long been registered and used in Zimbabwe as individual chemicals and their combination as a single product had never been tested. 1,3-D/C-35 at 36.9 ml/m2 was as effective as methyl bromide in nematode and weed control and led to similar seed germination and seedling growth rate. A combination of EDB at 21 ml/m2 and metham sodium at 35 ml/m2 was also equally effective. The use of 1,3-D alone at 35 ml/m2 gave unsatisfactory weed control and led to a reduced seedling growth rate. Metham sodium alone at 35 ml/m2 gave comparable weed control, seed germination and seedling growth comparable with methyl bromide. However nematode control evaluated using a gall rating scale was reduced. 1,3-D/C-35 at 36.9 ml/m2 and metham sodium at 35 ml/m2 used in combination with EDB at 21 ml/m2 are therefore, possible replacements for methyl bromide soil fumigation in tobacco seedbeds.

Animals↗

Efficacy of methyl bromide fumigation and insecticidal dips against Aedes eggs on lucky bamboo.

Importation of lucky bamboo (Dracaena sp.) stalk clusters has led to the accidental importation of Aedes albopictus in some countries. Current methods of fumigation using methyl bromide are harmful to live plants and thus are not acceptable. We exposed Aedes aegypti eggs to methyl bromide at rates of 32 g/m3 for 2 and 3 h and 48 g/m3 for 3 h, achieving complete control in 0/5, 1/5, and 5/5 replicates, respectively. Submersion for 1 min in aqueous solutions of 0.04% active ingredient (AI) lambda-cyhalothrin, 0.04% AI bifenthrin and carbaryl + malathion (both 0.1% AI) + petroleum oil (1% AI) provided 100% control of Ae. aegypti eggs laid on Dracaena stalk clusters. These methods, apparently harmless to plants, would have application in preventing the importation of exotic Aedes eggs on lucky bamboo shipments.

Aedes↗