SEARCH · PubMed Health

Results for “Volatile Organic Compounds”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources

PubMed1981

[A method for detection of volatile organic halogenated compounds in human and animal tissues (author's transl)].

A method is described which is suitable for detecting volatile halogenated hydrocarbons boiling from 60 degrees to 150 degrees C in human and animal tissues. Fried tissue samples of 10 grams are homogenized with Na2SO4. Stripped by nitrogen in an 80 degrees C water bath the compounds are sorbed on XAD-2 columns and desorbed by pentane. The pentane extract can directly be analyzed without further clean up, either by gas-liquid chromatography or by microcoulometry. Limits of detection achieved were between 6.2 X 10(-9) g/kg for carbon tetrachloride and 49 X 10(-9) g/kg for 1,1,2-trichloroethane. The recovery in human tissue is 87% as mean value.

Animals↗

PubMed2003

Role of Rhodobacter sp. strain PS9, a purple non-sulfur photosynthetic bacterium isolated from an anaerobic swine waste lagoon, in odor remediation.

Temporal pigmentation changes resulting from the development of a purple color in anaerobic swine waste lagoons were investigated during a 4-year period. The major purple photosynthetic bacterium responsible for these color changes and the corresponding reductions in odor was isolated from nine photosynthetic lagoons. By using morphological, physiological, and phylogenetic characterization methods we identified the predominant photosynthetic bacterium as a new strain of Rhodobacter, designated Rhodobacter sp. strain PS9. Rhodobacter sp. strain PS9 is capable of photoorganotrophic growth on a variety of organic compounds, including all of the characteristic volatile organic compounds (VOC) responsible for the odor associated with swine production facilities (J. A. Zahn, A. A. DiSpirito, Y. S. Do, B. E. Brooks, E. E. Copper, and J. L. Hatfield, J. Environ. Qual. 30:624-634, 2001). The seasonal variations in airborne VOC emitted from waste lagoons showed that there was a 80 to 93% decrease in the concentration of VOC during a photosynthetic bloom. During the height of a bloom, the Rhodobacter sp. strain PS9 population accounted for 10% of the total community and up to 27% of the eubacterial community based on 16S ribosomal DNA signals. Additional observations based on seasonal variations in meteorological, biological, and chemical parameters suggested that the photosynthetic blooms of Rhodobacter sp. strain PS9 were correlated with lagoon water temperature and with the concentrations of sulfate and phosphate. In addition, the photosynthetic blooms of Rhodobacter sp. strain PS9 were inversely correlated with the concentrations of protein and fluoride.

Anaerobiosis↗

PubMed1997

Evaluation of evaporation and concentration distribution models--a test chamber study.

Occupational exposure to airborne volatile organic compounds is governed by the source strength and dispersion of the pollutant into workroom air. The purpose of the present test chamber study was to validate suggested models for the prediction of evaporation rates and concentration distributions. The study design was organized into different scenarios to simulate workplace conditions. Evaporation rates of organic compounds of different volatilities were recorded gravimetrically and the corresponding concentrations in air were measured at various locations equally distributed in the test chamber. The evaporation models generally showed a fair agreement with experiments but tended to underestimate the evaporation rate especially at low air velocity. Based on factorial experiments a new simple evaporation model was suggested. The performances of the concentration distribution models were of different quality. The model developed by Roach (Annals of Occupational Hygiene 24, 105-132, 1981) cannot be used in predicting the concentration distribution in case of a convective air flow. If knowledge of the evaporation rate and pollutant concentration at some distances from the source were available, the model suggested by Scheff et al. (Applied Occupational and Environmental Hygiene 7, 127-134, 1992) generated a concentration distribution in reasonable agreement with the observed data. The box-model (Sinden, Building and Environment 13, 21-28, 1978) generally offered a fair performance but tended to underestimate the pollutant concentration in a region close to the source in the direction of the main air flow.

Air Pollution, Indoor↗

PubMed2003

Retrofitting existing chemical scrubbers to biotrickling filters for H2S emission control.

Biological treatment is a promising alternative to conventional air-pollution control methods, but thus far biotreatment processes for odor control have always required much larger reactor volumes than chemical scrubbers. We converted an existing full-scale chemical scrubber to a biological trickling filter and showed that effective treatment of hydrogen sulfide (H2S) in the converted scrubber was possible even at gas contact times as low as 1.6 s. That is 8-20 times shorter than previous biotrickling filtration reports and comparable to usual contact times in chemical scrubbers. Significant removal of reduced sulfur compounds, ammonia, and volatile organic compounds present in traces in the air was also observed. Continuous operation for >8 months showed stable performance and robust behavior for H2S treatment, with pollutant-removal performance comparable to that achieved by using a chemical scrubber. Our study demonstrates that biotrickling filters can replace chemical scrubbers and be a safer, more economical technique for odor control.

Air Pollution↗

PubMed2002

[Method for determining chlorinated solvent residues in dry cleaning fabrics with gas chromatography-mass spectrometry].

An analytical technique was provided for using headspace solid phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS) to estimates exposure and emissions of chlorinated hydrocarbon residues in dry cleaning fabrics or garments. Hazardous substances used by chlorinated dry cleaning operation include-perchloroethylene (PEC), trichloroethylene (TCE) and small amounts of trichloroethane, all known as volatile organic compounds (VOCs) listed in many professional testing criteria and limit values of pollutant control index. A standard fabric matrix was spiked with several chlorinated volatile organic compounds to achieve a theoretical concentration based on Oko-Tex Standard 100 levels. Samples were soaked in 5% (volume fraction) methanol saturated NaCl solution with supersonic treatment in a water-bath at (40 +/- 1) degree for 10 min, and then the solution extracted by headspace SPME with a 100 microns PDMS fiber was analyzed by GC-MS. The method gives the applicable range of 0.005 mg/kg-5.000 mg/kg for PCE and TCE, and 0.012 mg/kg-1.200 mg/kg for trichloroethane as the safe assessment of fabrics and garments in dry cleaning. The limits of detection for target compounds PCE, TCE and trichloroethane were 0.005 mg/kg with average recoveries between 90.6%-108.7%.

Clothing↗

PubMed1977

Intake system using glass ampoules for gas chromatographic analysis of volatile compounds of biological origin.

A gas chromatographic intake system using 1 ml glass ampoules is described. Examples of analyses of gases and volatile organic compounds produced by soil and soil organisms incubated in the ampoules are given. The gas chromatographic system was used to analyze permanent gases produced by germinating Fusarium conidia and by an agricultural soil as well as to study the respiration of Panagrellus nematodes. A comparison of the gas chromatograms of volatile organic compounds present in a beech forest soil and an agricultural soil indicates that the chromatograms represent "finger prints" of the two soils. Results obtained with the intake system described are compared to those obtained using a conventional head space technique.

Chromatography, Gas↗

PubMed1997

A quantitative property-property relationship (QPPR) approach to estimate in vitro tissue-blood partition coefficients of organic chemicals in rats and humans.

The present study describes quantitative property-property relationships (QPPRs) for the partitioning of organic chemicals between blood and tissue homogenates from both rats and humans. The n-octanol/water partition coefficient (K[ow]) is used as a non-biological descriptor. QPPRs for human tissue-blood partition coefficients (PCs) were derived from a dataset of 24 volatile organic compounds in blood, liver, muscle, fat, kidney and brain tissue homogenates. QPPRs were also derived for the PCs of rat tissues, using a dataset of 42 volatile organic compounds in blood, liver, muscle and fat tissue homogenates. These QPPRs were evaluated using a test set of 10 compounds for human tissues and a test set of 14 compounds for rat tissues. For both human and rat test sets, it was generally observed that most estimated PCs were within a range of 50-200% of their experimental values. The present approach is concluded to offer a rapid means for the estimation of tissue-blood PCs of compounds on the basis of K(ow) values. In addition, indications for a possible role of tissue components other than lipid and water in the tissue-blood partitioning process of compounds were observed from the calibration results of the model.

1-Octanol↗

PubMed2002

Volatile metabolites from microorganisms grown on humid building materials and synthetic media.

Growth of different microorganisms is often related to dampness in buildings. Both fungi and bacteria produce complicated mixtures of volatile organic compounds that include hydrocarbons, alcohols, ketones, sulfur- and nitrogen-containing compounds etc. Microbially produced substances are one possible explanation of odour problems and negative health effects in buildings affected by microbial growth. A mixture of five fungi, Aspergillus versicolor, Fusarium culmorum, Penicillium chrysogenum, Ulocladium botrytis and Wallemia sebi were grown on three different humid building materials (pinewood, particle board and gypsum board) and on one synthetic medium. Six different sampling methods were used, to be able to collect both non-reactive volatile organic compounds and reactive compounds such as volatile amines, aldehydes and carboxylic acids. Analysis was performed using gas chromatography, high-performance liquid chromatography and ion chromatography, mass spectrometry was used for identification of compounds. The main microbially produced metabolites found on pinewood were ketones (e.g. 2-heptanone) and alcohols (e.g. 2-methyl-1-propanol). Some of these compounds were also found on particle board, gypsum board and the synthetic medium, but there were more differences than similarities between the materials. For example, dimethoxymethane and 1,3,5-trioxepane and some nitrogen containing compounds were found only on particle board. The metabolite production on gypsum board was very low, although some terpenes (e.g. 3-carene) could be identified as fungal metabolites. On all materials, except gypsum board, the emission of aldehydes decreased during microbial growth. No low molecular weight carboxylic acids were identified.

Air Pollution, Indoor↗

PubMed2006

The molecular basis for wine grape quality--a volatile subject.

Volatile organic compounds are important flavor components of finished wines. In addition to winemaking practices, which shape wine quality, cultivation of the grape berries in the vineyard each season affects the production of volatile organic compounds as well as other chemical components that ultimately contribute to our perception of flavor in finished wines. By studying how berry flavor components are determined by the interplay of vine genotypes, the environment, and cultivation practices at the molecular level, scientists will develop advanced tools and knowledge that will aid viticulturalists in consistently producing balanced, flavorful berries for wine production.

Agriculture↗

PubMedDate not supplied

The spatial analysis of covariates in a study of environmental epidemiology.

Kanawha County, West Virginia, includes a deep river valley with a large population living in close proximity to many chemical manufacturing centres. One study of this area combined an epidemiologic survey of children attending Kanawha County schools with the measurement of the concentrations of 15 volatile organic compounds at each of the 75 elementary schools. Results have been reported by Ware et al. This paper further examines the associations of the concentrations of the ten individual volatile organic compounds related to chemical manufacturing processes with observed lower respiratory symptoms, generalizing the model of spatial variability and measurement error proposed by Donnelly et al. and using semi-variograms to assess the validity of model assumptions.

Air Pollution↗

PubMed2004

Industrial emissions cause extreme urban ozone diurnal variability.

Simulations with a regional chemical transport model show that anthropogenic emissions of volatile organic compounds and nitrogen oxides (NO(x) = NO + NO(2)) lead to a dramatic diurnal variation of surface ozone (O(3)) in Houston, Texas. During the daytime, photochemical oxidation of volatile organic compounds catalyzed by NO(x) results in episodes of elevated ambient O(3) levels significantly exceeding the National Ambient Air Quality Standard. The O(3) production rate in Houston is significantly higher than those found in other cities over the United States. At night, a surface NO(x) maximum occurs because of continuous NO emission from industrial sources, and, consequently, an extensive urban-scale "hole" of surface ozone (<10 parts per billion by volume in the entire Houston area) is formed as a result of O(3) removal by NO. The results suggest that consideration of regulatory control of O(3) precursor emissions from the industrial sources is essential to formulate ozone abatement strategies in this region.

Journal Article↗

PubMed1991

Indoor climate, air pollution, and human comfort.

The term sick building syndrome (SBS) is frequently used to describe a set of symptoms often reported by occupants of certain buildings. The symptoms are supposed to be direct or indirect consequences of an inadequate indoor climate. Typically, a majority of the occupants in these buildings complain, and the most frequent complaint is irritation of eyes, nose, and throat. Many different factors are known to be potential agents for the symptoms and no definitive causality has been identified yet. In consequence authors of publications on indoor air quality have been using the SBS term in different ways. A review of literature indicates that in supposed "sick buildings" only the prevalence of irritation of mucosal membranes and headaches seems to differ significantly from the prevalence in buildings considered to have a normal indoor climate. Volatile organic compounds (VOC) are known to have a potency to cause symptoms like those included in SBS. A dose-response relation for sensory reactions and mucosal irritation caused by volatile organic air pollutants is discussed, and a tentative guideline at 3 mg/m3 (about 0.9 PPM toluene equivalent) for the total volatile organic compounds (TVOC) is suggested for the nonindustrial indoor climates.

Air Pollution, Indoor↗

PubMed2000

Nicotine and 3-ethenylpyridine concentrations as markers for environmental tobacco smoke in restaurants.

The Finnish Tobacco Act has restricted smoking in public places since 1976, and in 1994 the Act was amended to include workplaces as well. In 2000, the Tobacco Act will be expanded further to restaurants. In Finland, the exposure of clients and employees to the vapor phase environmental tobacco smoke (ETS) in restaurants has not been systematically studied before by measuring ETS markers in indoor air. However, in these establishments the concentrations of ETS are expected to be much higher than in other workplaces. Gaseous nicotine and 3-ethenylpyridine were used as indicators of ETS in three different types of restaurants. Mean concentrations of nicotine ranged from 1.4-42.2 micrograms/m3 and 3-ethenylpyridine 1.4-6.3 micrograms/m3. In addition, concentrations of total volatile organic compounds (TVOC), CO and CO2 were measured and concentrations were 183-2215 micrograms/m3, 0.9-3.1 mg/m3 and 600-880 ppm, respectively. The concentrations of ETS markers were highest in discos and nightclubs and lowest in restaurants. The concentrations of total volatile organic compounds were highest in discos and nightclubs, especially when smoke generators were used.

Carcinogens↗

PubMed2006

Emission factors of air toxics from semiconductor manufacturing in Korea.

The development of local, accurate emission factors is very important for the estimation of reliable national emissions and air quality management. For that, this study is performed for pollutants released to the atmosphere with source-specific emission tests from the semiconductor manufacturing industry. The semiconductor manufacturing industry is one of the major sources of air toxics or hazardous air pollutants (HAPs); thus, understanding the emission characteristics of the emission source is a very important factor in the development of a control strategy. However, in Korea, there is a general lack of information available on air emissions from the semiconductor industry. The major emission sources of air toxics examined from the semiconductor manufacturing industry were wet chemical stations, coating applications, gaseous operations, photolithography, and miscellaneous devices in the wafer fabrication and semiconductor packaging processes. In this study, analyses of emission characteristics, and the estimations of emission data and factors for air toxics, such as acids, bases, heavy metals, and volatile organic compounds from the semiconductor manufacturing process have been performed. The concentration of hydrogen chloride from the packaging process was the highest among all of the processes. In addition, the emission factor of total volatile organic compounds (TVOCs) for the packaging process was higher than that of the wafer fabrication process. Emission factors estimated in this study were compared with those of Taiwan for evaluation, and they were found to be of similar level in the case of TVOCs and fluorine compounds.

Air Pollutants↗

PubMed2003

Pig slurry concentration by vacuum evaporation: influence of previous mesophilic anaerobic digestion process.

Water can be removed from pig slurry by evaporation, through the application of wasted heat from a power plant or from other processes. Apart from obtaining a concentrate with an obviously higher nutrient concentration than the original slurry, another objective of water removal is to obtain water as condensate, which could be reused. The objective of this work was to study the vacuum evaporation of pig slurry liquid fraction and to evaluate condensate composition as a function of both pH (4, 5, and 6) and pig slurry type (fresh slurry and anaerobically digested slurry). Batch experiments showed that condensate characteristics, total ammonia nitrogen (NH3-N), volatile fatty acids (VFA), and chemical oxygen demand were strongly dependent on initial slurry pH. In addition to producing part of the required thermal energy, previous anaerobic digestion presented several other clear advantages. The consumption of VFA and other volatile organic compounds during anaerobic digestion reduced the volatilization of organic matter in the evaporation treatment and, consequently, provided a higher quality condensate.

Animals↗

PubMed2005

Effects of feeding Spodoptera littoralis on lima bean leaves. II. Continuous mechanical wounding resembling insect feeding is sufficient to elicit herbivory-related volatile emission.

Herbivore feeding elicits defense responses in infested plants, including the emission of volatile organic compounds that can serve as indirect defense signals. Until now, the contribution of plant tissue wounding during the feeding process in the elicitation of defense responses has not been clear. For example, in lima bean (Phaseolus lunatus), the composition of the volatiles induced by both the insect caterpillar Spodoptera littoralis and the snail Cepaea hortensis is very similar. Thus, a mechanical caterpillar, MecWorm, has been designed and used in this study, which very closely resembles the herbivore-caused tissue damage in terms of similar physical appearance and long-lasting wounding period on defined leaf areas. This mode of treatment was sufficient to induce the emission of a volatile organic compound blend qualitatively similar to that as known from real herbivore feeding, although there were significant quantitative differences for a number of compounds. Moreover, both the duration and the area that has been mechanically damaged contribute to the induction of the whole volatile response. Based on those two parameters, time and area, which can replace each other to some extent, a damage level can be defined. That damage level exhibits a close linear relationship with the accumulation of fatty acid-derived volatiles and monoterpenes, while other terpenoid volatiles and methyl salicylate respond in a nonlinear manner. The results strongly suggest that the impact of mechanical wounding on the induction of defense responses during herbivore feeding was until now underestimated. Controlled and reproducible mechanical damage that strongly resembles the insect's feeding process represents a valuable tool for analyzing the role of the various signals involved in the induction of plant defense reactions against herbivory.

Animals↗

PubMed2006

Behavior of the GABIE, 3M 3500, PerkinElmer Tenax TA, and RADIELLO 145 diffusive samplers exposed over a long time to a low concentration of VOCs.

Diffusive sampling is particularly suited to determine time-weighted average volatile organic compound (VOC) concentration in occupational hygiene and environmental air monitoring. The purpose of this study was to measure the sampling rate variation of four different samplers in a special use--the exposure to a low concentration of volatile organic compound (10 to 200 ppb) for a long period (1 to 14 days). PerkinElmer tube-type adsorbent was packed with Tenax TA and RADIELLO cartridge packed with Carbograph 4. Badge-type activated carbon diffusive samplers 3M 3500 and GABIE were exposed to the same controlled atmospheres of benzene as meta-xylene (BTX) during the same exposure times. Performance samplers were observed for variability of uptake rates according to concentration levels, exposure duration, back diffusion, and competition phenomena at the adsorption sites. Particular benzene behavior has been noted for the thermally desorbable tube-type diffusive sampler: the measured sampling rates decrease with time following an exponential profile. With badge-type active charcoal diffusive samplers, the uptake rates were found to be highly stable and unaffected by time exposure. Overall, in the region of a few tens of ppb, for long-time exposure and for the lightest compounds, 3M 3500 and GABIE diffusive samplers seem the most appropriate diffusive sampling technique in terms of performance and facility in use.

Adsorption↗

PubMed2006

Metabolite production of yeasts on a strawberry-agar during storage at 7 degrees C in air and low oxygen atmosphere.

Changes of different quality factors of strawberries have been described until now from a physiological point of view. Possible effects on quality caused by yeast proliferation have not been described. To elucidate the metabolic activity of yeasts (i.e. Debaryomyces melissophilus, Rhodotorula glutinis, Cryptococcus laurentii), isolated from strawberries, they were inoculated on a simulation medium of strawberries (strawberry-agar). Their activity was measured by analysing and correlating microbiological counts, metabolite concentration in the headspace as well as in the medium, and sugar consumption. The isolated yeasts from strawberries could grow on the strawberry-agar, both under air conditions and modified atmosphere (MA) conditions. The maximum count for the yeasts reached 7.5-8.5 log cfu cm(-2) (air conditions) and 5.6-6.4 log cfu cm(-2) (MA conditions). Production or consumption of a number of compounds could be detected when microbial counts reached levels between 4.7 log cfu cm(-2) and 8.5 log cfu cm(-2) depending on species and atmospheric conditions. A range of volatile organic compounds, produced by the yeasts, was detected: acetone, ethyl acetate, ethanol, isopropyl acetate, ethyl butyrate, 1-propanol, 2-methyl-1-propanol, 1-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol and hexyl acetate. These compounds are able to influence the sensory properties of strawberries. A simultaneous decrease in sugar concentrations (sucrose, glucose, fructose) was observed. When ethanol reached high concentrations, ethyl acetate and ethyl butyrate were produced. This production can be attributed to a detoxification of ethanol by yeasts. The fermentative metabolism of yeasts during aerobic conditions could be explained by the Crabtree effect. As the detected volatile organic compounds produced by yeasts are also found in fresh strawberries, it can be concluded that these compounds are produced both by microbiological and physiological processes.

Colony Count, Microbial↗