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PubMed2001

Occurrence of organic pollutants in recovered soil fines from construction and demolition waste.

The objective of this study was to characterize recovered soil fines from construction and demolition (C&D) waste recycling facilities for trace organic pollutants. Over a period of 18 months, five sampling trips were made to 14 C&D waste recycling facilities in Florida. Screened soil fines were collected from older stockpiles and newly generated piles at the sites. The samples were analyzed for the total concentration (mg/kg) of a series of volatile organic compound (VOCs) and semi-volatile organic compounds (semi-VOCs). The synthetic precipitation leaching procedure (SPLP) test was also performed to evaluate the leachability of the trace organic chemicals. During the total analysis only a few volatile organic compounds were commonly found in the samples (trichlorofluoromethane, toluene, 4-isopropyltoluene, trimethylbenzene, xylenes, and methylene chloride). A total of nine VOCs were detected in the leaching test. Toluene showed the highest leachability among the compounds (61.3-92.0%), while trichlorofluoromethane, the most commonly detected compound from both the total and leaching tests, resulted in the lowest leachability (1.4-39.9%). For the semi-VOC analysis, three base-neutral semi-VOC compounds (bis(2-ethylhexyl)phthalate, butyl benzyl phthalate, and di-n-butyl phthalate) and several PAHs (acenaphthene, pyrene, fluoranthene, and phenanthrene) were commonly detected in C&D fines samples. These compounds also leached during the SPLP leaching test (0.1-25%). No acid extractable compounds, pesticides, or PCBs were detected. The results of this study were further investigated to assess risk from land applied recovered soil fines by comparing total and leaching concentrations of recovered soil fines samples to risk-based standards. The results of this indicate that the organic chemicals in recovered soil fines from C&D debris recycling facilities were not of a major concern in terms of human risk and leaching risk to groundwater under reuse and contact scenarios.

Conservation of Natural Resources↗

PubMed2001

Limitations to the use of solid-phase microextraction for quantitation of mixtures of volatile organic sulfur compounds.

A study of the range of volatile organic sulfur compounds produced by brassica plants has highlighted limitations to the use of Carboxen/PDMS fibers for their analysis by solid-phase microextraction (SPME). These fibers are sometimes advocated for the analysis of sulfur gases, but a quantitative comparison of analytical data derived by SPME and by direct gas sampling of standard mixtures of volatile low molecular weight sulfur compounds at 0.01-10 mg/L has identified potential errors associated with their use. Higher molecular compounds displace lower molecular weight compounds as a consequence of competition for active sites on the fiber, and the relative proportions of the components adsorbed onto the fiber depend on their ratio in the headspace. As their relative concentrations change from sample to sample, the varying interactions result in irregular analytical responses, reflected in erratic calibration curves. Standards containing single components are not valid; only a standard containing all components found in the sample to be analyzed, and at the same relative concentrations, is appropriate. In practice, this may preclude the use of the fibers for quantitative analysis of multicomponent mixtures.

Journal Article↗

PubMed2002

Microbial cycling of volatile organic sulfur compounds in anoxic environments.

Microbial cycling of volatile organic sulfur compounds (VOSC) is investigated due to the impact these compounds are thought to have on environmental processes like global temperature control, acid precipitation and the global sulfur cycle. Moreover, in several kinds of industries like composting plants and the paper industry VOSC are released causing odor problems. Waste streams containing these compounds must be treated in order to avoid the release of these compounds to the atmosphere. This paper describes the general mechanisms for the production and degradation of methanethiol (MT) and dimethyl sulfide (DMS), two ubiquitous VOSC in anaerobic environments. Slurry incubations indicated that methylation of sulfide and MT resulting in MT and DMS, respectively, is one of the major mechanisms for VOSC in sulfide-rich anaerobic environments. An anaerobic bacterium that is responsible for the formation of MT and DMS through the anaerobic methylation of H2S and MT was isolated from a freshwater pond after enrichment with syringate as a methyl group donating compound and sole carbon source. In spite of the continuous formation of MT and DMS, steady state concentrations are generally very low. This is due to the microbial degradation of these compounds. Experiments with sulfate-rich and sulfate-amended sediment slurries demonstrated that besides methanogens, sulfate-reducing bacteria can also degrade MT and DMS, provided that sulfate is available. A methanogen was isolated that is able to grow on DMS as the sole carbon source. A large survey of sediments slurries of various origin demonstrated that both isolates are commonly occurring inhabitants of anaerobic environments.

Acid Rain↗

PubMed2000

A larger pool of ozone-forming carbon compounds in urban atmospheres

Volatile organic compounds play a central role in the processes that generate both urban photochemical smog and tropospheric ozone. For successful and accurate prediction of these pollution episodes, identification of the dominant reactive species within the volatile organic carbon pool is needed. At present, lack of resolution inherent in single-column chromatographic analysis limits such a detailed chemical characterization of the complex urban atmosphere. Here we present an improved method of peak deconvolution from double-column (orthogonal) gas chromatography. This has enabled us to isolate and classify more than 500 chemical species of volatile organic compounds in urban air, including over 100 multi-substituted monoaromatic and volatile oxygenated hydrocarbons. We suggest that previous assessments of reactive carbon species may therefore have underestimated the contribution made by volatile organic compounds to urban pollution, particularly for compounds with more than six carbon atoms. Incorporating these species in predictive models should greatly improve our understanding of photochemical ozone yields and the formation of harmful secondary organic aerosols.

Journal Article↗

PubMed2006

The performance of a natural treatment system for landfill leachate with special emphasis on the fate of organic pollutants.

A natural treatment system for the treatment of leachate was studied at Moskogen landfill in southern Sweden. This facility consists of three consecutive ponds and a soil-plant (SP)-system. A test area, receiving water from the third pond with the same hydraulic load as the SP-system, was used for estimation of the latter system. Quality parameters including biochemical oxygen demand, total organic carbon, ammonium, nitrate, orthophosphate, and total suspended solids along the treatment line were determined as well as soluble metals (Cu, Cd, Zn, Cr, Ni, and Pb). In addition a thorough investigation along the treatment line has also been performed concerning volatile organic compounds and semi-volatile organic compounds. Non-polar organic compounds were investigated using gas chromatography-mass spectrometry. Quantification was based on the assumption of equal response for the compounds found in comparison with the chosen marker substances. For polar, water-soluble compounds the measurements were restricted to phenolic compounds using high-performance liquid chromatography. Several different types of organic compounds were found in the raw leachate including aromatics, benzene-sulfonamides, biphenyls, naphthalene, organic phosphates, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, phenols and phthalates. The treatment system efficiently reduced organic pollutants, heavy metals, and nitrogen/phosphorous compounds. Most metals and organic compounds in the leachate were already significantly reduced to a low level in the treatment ponds and ammonium-N was efficiently transformed to nitrate-N in the SP-system.

Chromatography, High Pressure Liquid↗

PubMed1996

A methodological approach for exposure assessment studies in residences using volatile organic compound-contaminated water.

This paper presents a methodological approach for assessing total exposures to volatile organic compounds (VOCs) in residences using contaminated water supplies. This approach is founded on assessment of ingestion, inhalation, and dermal exposures; both long-term (i.e., 12 to 24 hr) low-level exposures and short-term (i.e., approximately 10 min) high-level exposures are considered. The methodology is based on the collection of water samples to establish the identity of the contaminants, maximum source terms, and possible dermal and ingestion exposures; integrated whole-air samples are collected to assess long- and short-term inhalation exposures; whole-air grab samples are used to confirm peak and typical inhalation exposures; and alveolar breath samples are used to confirm exposures and to estimate contaminant concentrations in the blood of the test subjects. While we do not suggest that this methodology should supersede any current investigative approach, this material is primarily offered as a consolidated reference to the many people or organizations who might contemplate a study of this type. Application of this investigative protocol should provide detailed exposure assessment information, while it supplies critical real world data for risk assessment specialists, toxicologists, and modeling experts. Data from a recent field study assessing exposures to trichloroethylene are presented to illustrate the utility and some of the limitations of this strategy.

Administration, Inhalation↗

PubMed2004

Analysis of adsorption equilibrium of volatile chlorinated organic compounds to dry soil.

Adsorption is one of the main mechanisms of soil contamination by hazardous volatile chlorinated organic compounds. The adsorption equilibriums of six volatile organic chlorinated compounds to three dry soils were investigated using batch adsorption experiments. The adsorption equilibriums for the dry soils could be expressed by the Dubinin-Astakhov equation. The equation's parameters were analyzed with the characteristic values of the soils and compounds. No correlation between the values of the affinity coefficients, beta, and the molecular volume, Mv, was found. W(0) could be expressed by the functions of a pore volume of less than 10 nm, V(<10 nm), or the specific surface area, S. The adsorbed amount could be estimated using equations relating E(0), V(<10 nm) (or S), and beta. The predicted amounts agreed well with the measured data.

Adsorption↗

PubMedDate not supplied

Analysis of volatile and semivolatile hydrocarbons recovered from steam-classified municipal solid waste.

Hazardous household wastes comprise a significant proportion of municipal solid waste (MSW), and therefore serve as the source of many toxic or carcinogenic organic chemicals that are released in the environment through landfill gases or leachates. In the present study, we demonstrate the utility of the steam classification process in removing hazardous semivolatile organic compounds (SVOCs) and volatile organic compounds (VOCs) from MSW. Steam classification is a patented technology that involves the treatment of MSW with steam under pressure to yield a cellulosic biomass product that can be used as a fuel or in building materials. The SVOCs and VOCs from the waste off-gases are collected in the steam condensate and in an effluent charcoal filter. The results of this study show that at least two SVOCs and at least 17 VOCs can be removed from the waste. The most commonly identified compounds were diethylphthalate, styrene, 1,4-dichlorobenzene, and toluene in the condensates, and styrene, 1,1,1-trichloroethane, and toluene in the charcoal filters. On a weight basis, aromatic hydrocarbons were primarily recovered in the condensates, while the chloroaliphatic hydrocarbons were recovered almost exclusively from the charcoal filters. 1,3-Dichlorobenzene, 1,4-dichlorobenzene, and chloroform together comprised nearly 50% of the 4470 micrograms kg(-1) average mass of SVOCs and VOCs recovered from about 454 kg of MSW in these experiments. Toxicity characteristic leaching procedure (TCLP) analyses showed that steam classification recovered at least 75 to 91% of tested analytes. Overall, these results suggest that steam classification represents an effective technology for a significant reduction or the removal of hazardous organics from the waste stream, and, consequently, in reducing the extent of environmental contamination associated with landfill leachates and gases.

Environmental Pollutants↗

PubMed2001

Main findings and conclusions of the implementation of Directive 76/464/CEE concerning the monitoring of organic pollutants in surface waters (Portugal, April 1999-May 2000).

The purpose of this paper is to relate the implementation of Directive 76/464/CEE concerning the survey of priority dangerous substances and indicate the main priority pollutants encountered throughout a systematic monitoring program carried out in Portugal during a period of 14 months (April 1999-May 2000). Contrary to what it seems, the implementation of such a Directive is not straightforward owing to the large number of compounds and samples to be analyzed at trace levels. During this period of time, 115 priority semivolatile organic compounds (SVOCs), 41 volatile organic compounds (VOCs), six organotin compounds, 14 heavy metals, phosphate, nitrates, nitrites and ammonia were determined in 644 surface water samples (corresponding to 14 months and 46 sites). In addition, priority SVOCs were also determined in sediment, mussels and fish (muscle and liver). This paper reports the procedure and analytical tools used and necessary to determine the levels of 115 priority toxic and persistent semivolatile organic compounds selected from the EC Council Directive list (76/464/EEC). An advanced analytical protocol was developed involving enrichment of water samples in Oasis solid-phase extraction cartridges (SPE) in the Lisbon laboratory with a Gilson ASPEC XL automated extraction system and by sending the enriched cartridges to Barcelona by aeroplane at 4 degrees C, where elution and analysis were performed. Final determination was performed with gas chromatography-electron ionization mass spectrometry (GC-EI-MS). Acidic herbicides were determined by liquid chromatography with diode array detection. Owing to the great amount of data generated throughout the monitoring study, statistical analysis of the more representative contaminants was performed, allowing the identification of the more relevant contamination sources, percentages of findings and the description of their temporal and spatial (geographical) distributions. Recommendations and compounds that should be included in future monitoring programs are given.

Environmental Monitoring↗

PubMed2005

Gas-phase chemistry of (alpha-terpineol with ozone and OH radical: rate constants and products.

A bimolecular rate constant, kOH+alpha-terpineol, of (1.9 +/- 0.5) x 10(-10) cm3 molecule(-1) s(-1) was measured using gas chromatography/mass spectrometry and the relative rate technique for the reaction of the hydroxyl radical (OH) with alpha-terpineol (1-methyl-4-isopropyl-1-cyclohexen-8-ol) at (297 +/- 3) K and 1 atm total pressure. Additionally, a bimolecular rate constant, kO3+alpha-terpineol, of (3.0 +/- 0.2) x 10(-16) cm3 molecule(-1) s(-1) was measured by monitoring the first order decrease in ozone concentration as a function of excess alpha-terpineol. To better understand alpha-terpineol's gas-phase transformation in the indoor environment, the products of the alpha-terpineol + OH and alpha-terpineol + 03 reactions were also investigated. The positively identified alpha-terpineol/OH reaction products were acetone, ethanedial (glyoxal, HC(=O)C(=O)H), and 2-oxopropanal (methyl glyoxal, CH3C(=O)C(=O)H). The positively identified alpha-terpineol/O3 reaction product was 2-oxopropanal (methyl glyoxal, CH3C(=O)C(=O)H). The use of derivatizing agents O-(2,3,4,5,6-pentalfluorobenzyl)hydroxylamine (PFBHA) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) clearly indicated that several other reaction products were formed. The elucidation of these other reaction products was facilitated by mass spectrometry of the derivatized reaction products coupled with plausible alpha-terpineol/OH and alpha-terpineol/O3 reaction mechanisms based on previously published volatile organic compound/ OH and volatile organic compound/O3 gas-phase reaction mechanisms.

Air Pollutants↗

PubMed1990

Ground water and oil field waste sites: a study in Vermilion Parish.

Water samples were obtained from 128 private water wells surrounding eight oil field waste sites in Vermilion Parish. The specimens were analyzed for five heavy metals: barium, arsenic, chromium, lead, and cadmium. Half of the specimens were then analyzed for 16 volatile organic compounds. A blood sample was obtained from healthy adults drinking water from the wells tested for volatile organic compounds and this blood sample was also analyzed for volatile organic compounds. None of the water samples had levels of heavy metals or volatile organic compounds that exceeded the National Primary Drinking Water Standards. Barium levels in excess of 250 parts per billion suggested that styrene, toluene, and chloroform might be present. Blood levels of volatile organic compounds were significantly higher than could be accounted for by water consumption with levels in smokers significantly higher than in nonsmokers. These data suggest that as yet there is no contamination of ground water supplies around these sites. Volatile organic accumulation in humans probably occurs from a respiratory rather than from an oral route.

Humans↗

PubMed1990

[Volatile organic halogen compounds in food].

Volatile halocarbons have been found in raw water, chlorinated tap water, in blood of healthy individuals and patients, in milk, urine, solutions and laboratory suspensions manufactured by the Medical Industry. Tap water is also used in the food industry and therefore it is reasonable that they also could be analysed in food.

Animals↗

PubMed1998

Medical costs and lost productivity from health conditions at volatile organic compound-contaminated superfund sites.

This paper estimates the health costs at Superfund sites for conditions associated with volatile organic compounds (VOCs) in drinking water. Health conditions were identified from published literature and registry information as occurring at excess rates in VOC-exposed populations. These health conditions were: (1) some categories of birth defects, (2) urinary tract disorders, (3) diabetes, (4) eczema and skin conditions, (5) anemia, (6) speech and hearing impairments in children under 10 years of age, and (7) stroke. Excess rates were used to estimate the excess number of cases occurring among the total population living within one-half mile of 258 Superfund sites. These sites had evidence of completed human exposure pathways for VOCs in drinking water. For each type of medical condition, an individual's expected medical costs, long-term care costs, and lost work time due to illness or premature mortality were estimated. Costs were calculated to be approximately $330 million per year, in the absence of any remediation or public health intervention programs. The results indicate the general magnitude of the economic burden associated with a limited number of contaminants at a portion of all Superfund sites, thus suggesting that the burden would be greater than that estimated in this study if all contaminants at all Superfund sites could be taken into account.

Anemia↗

PubMedDate not supplied

Electronic nose based tea quality standardization.

In this paper we have used a metal oxide sensor (MOS) based electronic nose (EN) to analyze five tea samples with different qualities, namely, drier month, drier month again over-fired, well fermented normal fired in oven, well fermented overfired in oven, and under fermented normal fired in oven. The flavour of tea is determined mainly by its taste and smell, which is generated by hundreds of Volatile Organic Compounds (VOCs) and Non-Volatile Organic Compounds present in tea. These VOCs are present in different ratios and determine the quality of the tea. For example Assamica (Sri Lanka and Assam Tea) and Assamica Sinesis (Darjeeling and Japanese Tea) are two different species of tea giving different flavour notes. Tea flavour is traditionally measured through the use of a combination of conventional analytical instrumentation and human or ganoleptic profiling panels. These methods are expensive in terms of time and labour and also inaccurate because of a lack of either sensitivity or quantitative information. In this paper an investigation has been made to determine the flavours of different tea samples using an EN and to explore the possibility of replacing existing analytical and profiling panel methods. The technique uses an array of 4 MOSs, each of, which has an electrical resistance that has partial sensitivity to the headspace of tea. The signals from the sensor array are then conditioned by suitable interface circuitry. The data were processed using Principal Components Analysis (PCA), Fuzzy C Means algorithm (FCM). We also explored the use of a Self-Organizing Map (SOM) method along with a Radial Basis Function network (RBF) and a Probabilistic Neural Network classifier. Using FCM and SOM feature extraction techniques along with RBF neural network we achieved 100% correct classification for the five different tea samples with different qualities. These results prove that our EN is capable of discriminating between the flavours of teas manufactured under different processing conditions, viz. over-fermented, over-fired, under fermented, etc.

Chemoreceptor Cells↗

PubMed2003

Estimation of adsorbed amounts of volatile chlorinated organic compounds to wet soil based on the properties of the compounds and soils.

The adsorption equilibriums of 7 volatile organic chlorinated compounds to 10 wet soils were investigated by continuous flow adsorption experiments. The adsorption equilibriums for the wet soils could be expressed by the Henry equation. The most part of the adsorbed amount existed on the organic substances in the soil, and the soil-water adsorption equilibrium constant could be estimated from the organic carbon content of the soil. The adsorption coefficient to the organic carbon of the chloroethylenes and chloroethanes could be expressed by the functions of the n-octanol/water partition coefficient, respectively. The adsorbed amounts could be estimated using equations relating the organic content and the water content of each soil, and the n-octanol/water partition coefficient and the Henry constant for the gas-water equilibrium of each compound. The estimated results agreed well with the measured data.

Adsorption↗

PubMed1997

The effects on asthmatics of exposure to a conventional water-based and a volatile organic compound-free paint.

The water-based paints now frequently used for house painting still contain small amounts of volatile organic compounds (VOCs), with the potential to exacerbate symptoms of asthma. Because of these potential problems and environmental concerns, some manufacturers have produced paints with no VOC content. We wished to compare the effects on asthmatics of conventional water-based paint and the new VOC-free paint. Seventeen asthmatics were recruited on the basis of having previously reported exacerbation of symptoms by paint or other odours. Each undertook a standard painting task with identically coloured conventional acrylic and VOC-free paints in a double-blind, crossover study. Respiratory symptoms, lung function, and airway responsiveness were measured at each visit. A significant increase in reported "wheeze" was detected during use of conventional paint (p<0.01), but not with the new paint. There was also a significantly greater increase in reported "breathlessness" whilst using conventional paint than with the new paint (p<0.05). In contrast, lung function measurements showed a small but significant increase during the use of both paints (p<0.05). There was no significant change in airway responsiveness after use of either paint. The new paint appears to be less likely to cause a worsening of respiratory symptoms than conventional acrylic paint, although this difference is not reflected in measurements of lung function or airway responsiveness. Although the benefit conferred in the majority of asthmatics is probably modest, there may be some patients with an increased sensitivity to paint odour, who would derive a useful symptomatic benefit from using the VOC-free paint.

Adult↗

PubMed2003

Emission of biocides from treated materials: test procedures for water and air.

Methods for the determination of biocide emissions from treated materials into water and air were developed and tested in order to support a comparative ecological assessment of biocidal products. Leaching tests, experiments with simulated rain, extraction cleaning of carpets and emission chamber tests were performed with a series of treated materials. The experiments focused on the effect of changes in the procedure as well as characteristics of the specimens and demonstrate the suitability of the proposed methods for biocides of different product types. It was demonstrated that emissions of biocides into water can be compared on the basis of leaching tests in which the emission kinetics of the active ingredients are recorded. However, the water volume per surface area and the timetable for water changes have to be defined in such tests. Functions of flux rates related to time can be well described for inorganic compounds, whereas modelling of the data is more complicated for organic substances. Emission chamber tests using 20-litre and 23-litre glass exsiccators, originally developed to study volatile organic compounds, were successfully adapted for the investigation of the emission of biocides from treated materials which are usually semi volatile organic compounds. However test parameters and the method of analysis have to be adapted to the substances to be determined. Generally, it was found that the emission curves for the semi volatile organic compounds investigated differ from those of volatile organic compounds.

Air Pollutants↗

PubMed2000

Volatile metabolites from mold growth on building materials and synthetic media.

Mold species which were isolated from damp buildings were grown on sterile building materials and some synthetic media in order to study the microbial volatile organic compounds produced. Patterns of the microbial volatile organic compounds (MVOC) were very media dependent but media which favor terpene biosynthesis may give patterns unique enough for identification of dominant indoor molds.

Air Pollutants↗