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At least 793 records · Page 44Linked to original sources

PubMed2003

A review of aqueous-phase VOC transport in modern landfill liners.

Leachates from municipal solid waste (MSW) and hazardous waste landfills contain a wide range of volatile organic compounds (VOCs) in addition to inorganic compounds. VOCs have been shown to migrate and contaminate the surrounding environment and impair the use of groundwater. Therefore, the effectiveness of modern landfill liner systems to minimize migration of VOCs is of concern. Most modern landfills employ a composite liner consisting of a geomembrane overlying a compacted clay liner or a geosynthetic clay liner. The geomembrane is often believed to be the primary barrier to contaminant transport. However, for VOCs, the clay component usually controls the rate of transport since VOCs are shown to diffuse through geomembrane at appreciable rates. Additionally, analyses have shown that transport of volatile organic compounds (VOCs) generally is more critical than transport of inorganic compounds (e.g., toxic heavy metals), even though VOCs are often found at lower concentrations in leachates. Therefore, the effectiveness of modern landfill liner systems to minimize migration of VOCs and transport of VOCs through clay liners and modeling of transport through composite liners merit scrutiny. This paper presents a review of recent research by the author and others on these topics. A systematic and comprehensive approach to determine mass transport parameters for transport of VOCs in liquid phase through compacted clay liners, geosynthetic clay liners (GCLs), and geomembranes has enabled to develop realistic models to predict mass flux of VOCs through modern composite liners and provide a quantitative basis to evaluate potential for transport of dissolved VOCs and the equivalency of different composite liners.

Aluminum Silicates↗

PubMed2005

Estimation of the volatilization of organic compounds from soil surfaces.

Several simple models for the estimation of the half-life (t(1/2)) for the depletion of an organic chemical from a soil surface to air were examined. For moist surfaces, two models are proposed: the first requires knowledge of the soil/organic carbon partition coefficient (K(oc)) and the Henry's law constant (H) and the second the vapor pressure (P(s)) of the chemical involved. Due to uncertainties in the experimental K(oc) values those ones predicted by the group-contribution model of Meylan et al. [Environ. Sci. Technol. 26 (1992) 1560]-and proposed by the U.S. Environmental Protection Agency (EPA)-should be used. If reliable experimental P(s) values are not available, the first model is proposed, where in cases when H values are not available, predicted ones by the Bond-Contribution method of Meylan and Howard [Environ. Toxicol. Chem. 10 (1991) 1283]-and also proposed by EPA-can be used. In general, the agreement of the predicted t(1/2) values with the measured ones is within a factor of 3-5. Similar expressions, but with somewhat poorer results, are presented for dry field soils. In all cases, the obtained results represent a substantial improvement over those obtained with the currently used Dow method: t(1/2) = 1.58 x 10(-8)((K(oc) x S)/P(S)), where S is the solubility of the compound in water.

Half-Life↗

PubMedDate not supplied

Functional classification of swine manure management systems based on effluent and gas emission characteristics.

Gaseous emissions from swine (Sus scrofa) manure storage systems represent a concern to air quality due to the potential effects of hydrogen sulfide, ammonia, methane, and volatile organic compounds on environmental quality and human health. The lack of knowledge concerning functional aspects of swine manure management systems has been a major obstacle in the development and optimization of emission abatement technologies for these point sources. In this study, a classification system based on gas emission characteristics and effluent concentrations of total phosphorus (P) and total sulfur (S) was devised and tested on 29 swine manure management systems in Iowa, Oklahoma, and North Carolina in an effort to elucidate functional characteristics of these systems. Four swine manure management system classes were identified that differed in effluent concentrations of P and S, methane (CH4) emission rate, odor intensity, and air concentration of volatile organic compounds (VOCs). Odor intensity and the concentration of VOCs in air emitted from swine manure management systems were strongly correlated (r2 = 0.88). The concentration of VOC in air samples was highest with outdoor swine manure management systems that received a high input of volatile solids (Type 2). These systems were also shown to have the highest odor intensity levels. The emission rate for VOCs and the odor intensity associated with swine manure management systems were inversely correlated with CH4 and ammonia (NH3) emission rates. The emission rates of CH4, NH3, and VOCs were found to be dependent upon manure loading rate and were indirectly influenced by animal numbers.

Agriculture↗

PubMed2005

Stop-flow programmable selectivity with a dual-column ensemble of microfabricated etched silicon columns and air as carrier gas.

A series-coupled ensemble of microfabricated GC columns made by dry reactive ion etching of silicon substrates is evaluated for use with pneumatic selectivity enhancement techniques for targeted pairs of volatile organic compounds. Each column is 3.0 m long with a 150 miceom wide by 240 microm deep cross section. Dynamic coating was used to prepare a nonpolar column with a dimethyl polysiloxane stationary phase and a moderately polar column with a trifluoropropylmethyl polysiloxane stationary phase. Each column generates 5000-6000 theoretical plates. The columns are operated in series with the nonpolar column connected to a split inlet, the polar column connected to a flame ionization detector, and a valve connected between the column junction point and the inlet to the first column. When the valve is closed, the effluent from the first column passes directly into the second column. When the valve is open, both ends of the first column are at the inlet pressure, and flow stops in this column while increased flow is obtained in the second column. For analyte pairs that are separated by the first column but coelute from the column ensemble, the valve is opened for a few seconds after the first component of the pair has passed into the second column but the second component is still in the first column. The result is enhanced separation of the pair in the ensemble chromatogram. Relatively thick cross-linked stationary-phase films are used to increase retention for volatile compounds. The combination of air carrier gas and stationary-phase film thickness in the range 1-2 microm requires the use of relatively low average carrier gas velocities (typically less than 10 cm/s) for adequate resolving power of the column ensemble. Selectivity enhancement under isothermal conditions for a 14-component mixture of volatile organic compounds is demonstrated where neither of the columns alone nor the column ensemble without selectivity enhancement could obtain a complete separation.

Air↗

PubMed1997

Concentrations of selected contaminants in cabin air of airbus aircrafts.

The concentrations of selected air quality parameters in aircraft cabins were investigated including particle numbers in cabin air compared to fresh air and recirculation air, the microbiological contamination and the concentration of volatile organic compounds (VOC). The Airbus types A310 of Swissair and A340 of Lufthansa were used for measurements. The particles were found to be mainly emitted by the passengers, especially by smokers. Depending on recirculation filter efficiency the recirculation air contained a lower or equal amount of particles compared to the fresh air, whereas the amount of bacteria exceeded reported concentrations within other indoor spaces. The detected species were mainly non-pathogenic, with droplet infection over short distances identified as the only health risk. The concentration of volatile organic compounds (VOC) were well below threshold values. Ethanol was identified as the compound with the highest amount in cabin air. Further organics were emitted by the passengers--as metabolic products or by smoking--and on ground as engine exhaust (bad airport air quality). Cleaning agents may be the source of further compounds.

Air Microbiology↗

PubMed2001

Ambient air quality at the site of a former manufactured gas plant.

Prior to the 1950's, manufactured gas was commercially produced from the pyrolysis of coal, coke, and oil at facilities that are termed manufactured gas plants (MGPs). The constituents of residual coal tar present on many MGP sites are an environmental health concern because of their toxicity and the possibility for their off-site migration via water and air. Atmospheric concentrations of five volatile organic compounds (VOCs, e.g., benzene), sixteen polycyclic aromatic hydrocarbons (PAHs, e.g., naphthalene) and particulate matter less than 10 microns in aerodynamic diameter (PM10) were measured at the site of a former MGP. Air samples were obtained before, during, and after excavation of subterranean coal tar at the site. The results of this investigation indicate that subterranean coal tar was not a primary source of VOCs and PAHs in the local atmosphere before or after remediation of the site. However, excavation, treatment, blending, and transfer of the coal tar during remediation generated concentrations of selected aromatic and semi-volatile organic compounds that were substantially greater than typical ambient levels. In addition, these data suggest that blending and mixing of coal tars could lead to exceedance of the U.S. National Ambient Air Quality Standard for PM10, although additional research is required to fully evaluate this possibility. Nuisance odors associated with the site remediation were likely the result of naphthalene and possibly isomers of xylene. Air pollutant concentrations measured adjacent to the excavation area and at the site perimeter during remediation activities were less than the relevant occupational and environmental exposure limits.

Air Pollution↗

PubMed2003

Isolation, characterisation and identification of lactic acid bacteria from bushera: a Ugandan traditional fermented beverage.

One hundred and thirteen strains of lactic acid bacteria (LAB) were selected from 351 isolates from 15 samples of traditionally fermented household bushera from Uganda and also from laboratory-prepared bushera. Isolates were phenotypically characterised by their ability to ferment 49 carbohydrates using API 50 CHL kits and additional biochemical tests. Coliforms, yeasts and LAB were enumerated in bushera. The pH, volatile organic compounds and organic acids were also determined. The LAB counts in household bushera varied between 7.1 and 9.4 log cfu ml(-1). The coliform counts varied between < 1 and 5.2 log cfu ml(-1). The pH of bushera ranged from 3.7 to 4.5. Ethanol (max, 0.27%) was the major volatile organic compound while lactic acid (max, 0.52%) was identified as the dominant organic acid in household bushera. The initial numbers of LAB and coliforms in laboratory-fermented bushera were similar; however, the LAB numbers increased faster during the first 24 h. LAB counts increased from 5.5 to 9.0 log cfu ml(-1) during the laboratory fermentation. Coliform counts increased from 5.9 to 7.8 log cfu ml(-1) at 24 h, but after 48 h, counts were less 4 log cfu ml(-1). Yeasts increased from 4.3 to 7.7 log cfu ml(-1) at 48 h, but thereafter decreased slightly. The pH declined from 7.0 to around 4.0. Lactic acid and ethanol increased from zero to 0.75% and 0.20%, respectively. Lactic acid bacteria isolated from household bushera belonged to Lactobacillus, Streptococcus and Enterococcus genera. Tentatively, Lactobacillus isolates were identified as Lactobacillus plantarum, L. paracasei subsp. paracasei, L. fermentum, L. brevis and L. delbrueckii subsp. delbrueckii. Streptococcus thermophilus strains were also identified in household bushera. LAB isolated from bushera produced in the laboratory belonged to five genera (Lactococcus, Leuconostoc, Lactobacillus, Weissella and Enterococcus. Eight isolates were able to produce acid from starch and were identified as Lactococcus lactis subsp. lactis (four strains), Leuconostoc mesenteroides subsp. mesenteroides (one strain), Leuconostoc mesenteroides subsp. dextranicum (one strain), Weissella confusa (one strain) and L. plantarum (one strain).

Beverages↗

PubMed1994

Effect of air humidification on the sick building syndrome and perceived indoor air quality in hospitals: a four month longitudinal study.

The sensation of dryness and irritation is essential in the sick building syndrome (SBS), and such symptoms are common in both office and hospital employees. In Scandinavia, the indoor relative humidity in well ventilated buildings is usually in the range 10-35% in winter. The aim of this study was to evaluate the effect of steam air humidification on SBS and perceived air quality during the heating season. The study base consisted of a dynamic population of 104 hospital employees, working in four new and well ventilated geriatric hospital units in southern Sweden. Air humidification raised the relative air humidity to 40-45% in two units during a four months period, whereas the other two units served as controls with relative humidity from 25-35%. Symptoms and perceived indoor air quality were measured before and after the study period by a standardised self administered questionnaire. The technical measurements comprised room temperature, air humidity, static electricity, exhaust air flow, aerosols, microorganisms, and volatile organic compounds in the air. The most pronounced effect of the humidification was a significant decrease of the sensation of air dryness, static electricity, and airway symptoms. After four months of air humidification during the heating season, 24% reported a weekly sensation of dryness in humidified units, compared with 73% in controls. No significant changes in symptoms of SBS or perceived air quality over time were found in the control group. The room temperature in all units was between 21-23 degrees C, and no significant effect of air humidification on the air concentration of aerosols or volatile organic compounds was found. No growth of microorganisms was found in the supply air ducts, and no legionella bacteria were found in the supply water of the humidifier. Air humidification, however, significantly reduced the measured personal exposure to static electricity. It is concluded that air humidification during the heating season in colder climates can decrease symptoms of SBS and perception of dry air.

Adult↗

PubMedDate not supplied

[Air pollution and the lung: epidemiological approach].

Epidemiological evidence has concurred with clinical and experimental evidence to correlate current levels of ambient air pollution, both indoors and outdoors, with respiratory effects. In this respect, the use of specific epidemiological methods has been crucial. Common outdoor pollutants are particulate matter, nitrogen dioxide, carbon monoxide, volatile organic compounds and ozone. Short-term effects of outdoor air pollution include changes in lung function, respiratory symptoms and mortality due to respiratory causes. Increase in the use of health care resources has also been associated with short-term effects of air pollution. Long-term effects of cumulated exposure to urban air pollution include lung growth impairment, chronic obstructive pulmonary disease (COPD), lung cancer, and probably the development of asthma and allergies. Lung cancer and COPD have been related to a shorter life expectancy. Common indoor pollutants are environmental tobacco smoke, particulate matter, nitrogen dioxide, carbon monoxide, volatile organic compounds and biological allergens. Concentrations of these pollutants can be many times higher indoors than outdoors. Indoor air pollution may increase the risk of irritation phenomena, allergic sensitisation, acute and chronic respiratory disorders and lung function impairment. Recent conservative estimates have shown that 1.5-2 million deaths per year worldwide could be attributed to indoor air pollution. Further epidemiological research is necessary to better evaluate the respiratory health effects of air pollution and to implement protective programmes for public health.

Air Pollutants↗

PubMed2006

Analysis of chemical kinetics at the gas-aqueous interface for submicron aerosols.

The effect of kinetics of chemical reactions in the gas-liquid interface between atmospheric gases and reactive solute in dilute aqueous aerosols is analysed in order to see if such processes will affect the overall uptake rate. Accordingly, a parameterization of such heterogeneous reactions was derived, taking into account interfacial reactions. Gibbs surface excess concentration of both reactive compounds and stable compounds leads to higher heterogeneous reaction rates in comparison to aqueous phase bulk reactions. An analytical formulation shows that the surface reactions may be of considerable importance for the uptake process in the case of small liquid aerosols even in the absence of organic film on the surface. In particular, we demonstrate that the uptake rate of atmospheric gas-phase oxidants (such as OH, NO(3) or O(3)) reacting with volatile organic compounds (such as ethanol or methanol) is increased by more than 10% for atmospheric aerosols with diameters lower than 0.1 microm. This effect is in addition intensified in the case of reactions of atmospheric oxidants with liquid aerosols containing organic surfactants, such as semi-volatile organic compounds, i.e., the chemical reactions at the gas-liquid interface may be dominant in the main uptake process for atmospheric submicron aerosols.

Aerosols↗

PubMed2003

Indoor air quality, ventilation and health symptoms in schools: an analysis of existing information.

We reviewed the literature on Indoor Air Quality (IAQ), ventilation, and building-related health problems in schools and identified commonly reported building-related health symptoms involving schools until 1999. We collected existing data on ventilation rates, carbon dioxide (CO2) concentrations and symptom-relevant indoor air contaminants, and evaluated information on causal relationships between pollutant exposures and health symptoms. Reported ventilation and CO2 data strongly indicate that ventilation is inadequate in many classrooms, possibly leading to health symptoms. Adequate ventilation should be a major focus of design or remediation efforts. Total volatile organic compounds, formaldehyde (HCHO) and microbiological contaminants are reported. Low HCHO concentrations were unlikely to cause acute irritant symptoms (<0.05 ppm), but possibly increased risks for allergen sensitivities, chronic irritation, and cancer. Reported microbiological contaminants included allergens in deposited dust, fungi, and bacteria. Levels of specific allergens were sufficient to cause symptoms in allergic occupants. Measurements of airborne bacteria and airborne and surface fungal spores were reported in schoolrooms. Asthma and 'sick building syndrome' symptoms are commonly reported. The few studies investigating causal relationships between health symptoms and exposures to specific pollutants suggest that such symptoms in schools are related to exposures to volatile organic compounds (VOCs), molds and microbial VOCs, and allergens.

Air Pollution, Indoor↗

PubMedDate not supplied

The identification of polar organic compounds found in consumer products and their toxicological properties.

Exposure to volatile organic compounds (VOCs) in the indoor environment has received substantial research attention in the past several years, with the goal of better understanding the impact of such exposures on human health and well-being. Many VOCs can arise from consumer products used within the indoor environment. The VOCs emitted from five representative consumer products were collected onto Tenax-GC and subjected to thermal desorption and analysis by gas chromatography, in combination with low-resolution mass spectrometry (MS), high-resolution MS, and matrix-isolation Fourier transform infrared spectroscopy for structural characterization. An emphasis was placed on the polar organic compounds often used to provide fragrance in these products. The structures of a number of these compounds were confirmed, and an electronic literature search was carried out on them to determine any known toxic properties. The search revealed that many of the VOCs possess toxic properties when studied at acute, relatively high-level exposures. In addition, toxic effects were reported for a few of the chemicals, such as benzaldehyde, alpha-terpineol, benzyl acetate, and ethanol, at relatively low dose levels of 9-14 mg/kg. In general, the data were unclear as to the effect of chronic, low-level exposures. The widespread use of such chemicals suggests that the health effects of chronic exposures need to be determined. Validated analytical methods for the quantitative characterization of polar organic compounds at low concentrations will be required to make such work possible.

Air Pollution, Indoor↗

PubMed1998

Migration patterns of children with cancer in Britain.

OBJECTIVES: To investigate the early migration patterns of children who later developed cancer. To test a prior hypothesis that some cancers are initiated by early exposures to toxic atmospheric pollutants from point sources. DESIGN: Address changes in children dying from cancer are examined in relation to potentially hazardous sites of several different types. The relative proximities of birth addresses and death addresses to these sites, are compared. The approach is based upon the premise that a local exposure, effective only at an early age, must be preferentially linked with an early address. SETTING AND SUBJECTS: Records of 22,458 children dying from leukaemia or other cancer under the age of 16 years in Great Britain between 1953 and 1980: including 9224 who moved house between birth and death. The migration analysis was based upon birth and death addresses, converted first to postcodes and thence to map coordinates. The geographical locations of potentially toxic industrial sites were obtained through direct map searches and from commercial directories. RESULTS: Systematic asymmetries were found between measured distances from birth and death addresses to sources emitting volatile organic compounds, or using large scale combustion processes. The children had more often moved away from these hazards than towards them. Many of the sources had already been identified as hazardous using other methods. There was also a birth association with areas of dense habitation; possibly because of unidentified toxic sources contained within them. All forms of cancer were involved although some effluents were associated preferentially with specific types. CONCLUSIONS: The main findings of an earlier study, based upon a different and independent method, were confirmed. Proximities to several types of industrial source, around the time of birth, were followed by a raised risk of childhood cancer. Combustion products and volatile organic compounds were especially implicated. Within the 16 year limit of the study, the increased risk did not decay with advancing age. Low atmospheric concentrations of many carcinogenic substances suggest that the mother acts as a cumulative filter and passes them to the fetus across the placenta or in breast milk.

Adolescent↗

PubMed2000

Membrane extraction with a sorbent interface for headspace monitoring of aqueous samples using a cap sampling device

A cap-shaped device was employed for headspace sampling. This sampling device coupled to membrane extraction with a sorbent interface (MESI) is intended to perform on-site and on-line aqueous sample monitoring. A laboratory sampling testwas performed both at the water surface and under water, and it showed some advantages in underwater monitoring. A group of volatile organic compounds (VOCs), varying in PDMS/gas and gas/water distribution constants, benzene, toluene, ethylbenzene, o-xylene, and trichloroethylene (TCE), was used for the sampling study. Magnetic stirring of the sample and circulation of the headspace air with a microfan were used for the enhancement of mass transfer between sample matrix and membrane to obtain higher extraction rate and efficiency. The agitation approaches were investigated individually and compared. The results showed that simultaneous agitation in water and air could greatly improve the extraction efficiency. Good linearity and precision and low detection limits were obtained for water-surface monitoring. The study demonstrated that Cap-MESI is a useful tool for field headspace monitoring of volatile organic compounds.

Journal Article↗

PubMed2006

DNA damage in outdoor workers occupationally exposed to environmental air pollutants.

BACKGROUND: Health concerns about the exposure to genotoxic and carcinogenic agents in the air are particularly significant for outdoor workers in less developed countries. AIMS: To investigate the association between personal exposure to a group of air pollutants and severity of DNA damage in outdoor workers from two Mexican cities. METHODS: DNA damage (Comet assay) and personal exposure to volatile organic compounds, PM(2.5), and ozone were investigated in 55 outdoor and indoor workers from México City and Puebla. RESULTS: In México City, outdoor workers had greater DNA damage, reflected by a longer tail length, than indoor workers (median 46.8 v 30.1 mum), and a greater percentage of highly damaged cells (cells with tail length > or =41 microm); in Puebla, outdoor and indoor workers had similar DNA damage. There were more alkali labile sites in outdoor than indoor workers. The DNA damage magnitude was positively correlated with PM(2.5) and ozone exposure. Outdoor and indoor workers with > or =60% of highly damaged cells (highly damaged workers) had significantly higher exposures to PM(2.5), ozone, and some volatile organic compounds. The main factors associated with the highly damaged workers were ozone, PM(2.5), and 1-ethyl-2-methyl benzene exposure. CONCLUSIONS: With this approach, the effects of some air pollutants could be correlated with biological endpoints from the Comet assay. It is suggested that the use of personal exposure assessment and biological endpoints evaluation could be an important tool to generate a more precise assessment of the associated potential health risks.

Adolescent↗

PubMedDate not supplied

Characterization of emissions during the heating of tyre contaminated scrap.

In order to characterize the compounds (type and quantities) emitted during melting of organic contaminated scrap and to investigate the mechanism of their formation, an experimental set-up has been designed and built to study precisely the influence of temperature and gas atmosphere in the conditions of an electric arc furnace. These experiments lead to the determination of mass balances (C, H, O, S) and to the quantification of unburnt compounds (tars, carbon monoxide, volatile organic compounds (VOCs), benzene, toluene, ethylbenzene and xylenes (BTEX), polyaromatic compounds (PAHs)). Degradation conditions (gas atmosphere and temperature) corresponding to different areas in the electric furnace have also been investigated. Such experiments lead to a better understanding of degradation mechanisms; this interpretation is not possible from investigations performed in an industrial furnace since there are many uncontrolled parameters (large dispersion of the results).

Journal Article↗

PubMed2000

Orbital cortex neuronal responses during an odor-based conditioned associative task in rats.

Neuronal activity in the rat orbital cortex during discrimination of various odors [five volatile organic compounds (acetophenone, isoamyl acetate, cyclohexanone, p-cymene and 1,8-cineole), and food- and cosmetic-related odorants (black pepper, cheese, rose and perfume)] and other conditioned sensory stimuli (tones, light and air puff) was recorded and compared with behavioral responses to the same odors (black pepper, cheese, rose and perfume). In a neurophysiological study, the rats were trained to lick a spout that protruded close to its mouth to obtain sucrose or intracranial self-stimulation reward after presentation of conditioned stimuli. Of 150 orbital cortex neurons recorded during the task, 65 responded to one or more types of sensory stimuli. Of these, 73.8% (48/65) responded during presentation of an odor. Although the mean breadth of responsiveness (entropy) of the olfactory neurons based on the responses to five volatile organic compounds and air (control) was rather high (0.795), these stimuli were well discriminated in an odor space resulting from multidimensional scaling using Pearson's correlation coefficients between the stimuli. In a behavioral study, a rat was housed in an equilateral octagonal cage, with free access to food and choice among eight levers, four of which elicited only water (no odor, controls), and four of which elicited both water and one of four odors (black pepper, cheese, rose or perfume). Lever presses for each odor and control were counted. Distributions of these five stimuli (four odors and air) in an odor space derived from the multidimensional scaling using Pearson's correlation coefficients based on behavioral responses were very similar to those based on neuronal responses to the same five stimuli. Furthermore, Pearson's correlation coefficients between the same five stimuli based on the neuronal responses and those based on behavioral responses were significantly correlated. The results demonstrated a pivotal role of the rat orbital cortex in olfactory sensory processing and suggest that the orbital cortex is important in the manifestation of various motivated behaviors of the animals, including odor-guided motivational behaviors (odor preference).

Animal Feed↗

PubMed1980

Distribution of volatile halogenated organic compounds between rat blood serum and adipose tissue.

A 31-day rat-dosing sequence was used to study some aspects of the physiological distribution, metabolism, storage and rate of elimination of chloroform, trichloroethylene, carbon tetrachloride and bromodichloromethane from rat adipose tissue and blood serum. Data points were collected nine times during the dosing period and twice after dosing had ceased. Purge/trap/desorb methodology was employed using a liquid sample concentrator, a gas-liquid chromatograph and a Hall electrolytic conductivity detector in series. Compound identities were confirmed using a GC/MS analytical system. For these volatile compounds, tissue levels fluctuated but did not indicate increased storage with time. Adipose tissue to blood serum levels never differed by more than a factor of three. Within 3-6 days after dosing was terminated, practically all of the halogenated compounds had left the examined tissues. Metabolic conversion of trichloroethylene and carbon tetrachloride into chloroform and/or a chloroform precursor was observed; bromodichloromethane-dosed animals did not have serum chloroform levels exceeding those observed for the control animals.

Adipose Tissue↗