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Biomedical subjects

E D Pellizzari

Publications and source records attributed to E D Pellizzari.

At least 19 recordsLinked to original sources
PubMed1991

Use of a pilot study for designing a large scale probability study of personal exposure to aerosols.

The major objective of the U.S. Environmental Protection Agency's (EPA's) Particle Total Exposure Assessment Methodology (PTEAM) Study is to estimate the frequency distribution of aerosol exposures of a target population of individuals. This objective requires the use of probability sampling techniques for selecting a representative sample of participants from a prescribed target population. To design such a population exposure study in a cost-effective fashion, a number of issues must be addressed. For instance, when and for how long and for whom should personal samples be obtained? What other samples are needed or desirable? Issues like these must be considered from several perspectives--from the point of view of data collection costs, burden on participants, precision and representativeness of resultant estimates, etc. To help address such design issues for the PTEAM population exposure study, we generated descriptive statistics and performed statistical analyses on data from a preliminary nine-home pilot study conducted in March 1989 in the San Gabriel Valley area of Southern California. The analyses showed large temporal variation, with day versus night being a major component (generally higher daytime concentrations); large systematic time-of-week differences were not found. Large house-to-house and person-to-person variabilities were evident, with high exposure levels noted especially in homes with tobacco smoking. Within many homes, there appeared to be little variability in the particulate concentrations among different rooms. The results of the pilot were used to make decisions regarding the spatial and temporal sampling units, the benefits of stratification, and the overall allocation of resources (e.g., multiple monitors within a home versus more homes and participants) for the subsequent population study.

Aerosols↗
PubMed1991

Elimination of volatile organic compounds in breath after exposure to occupational and environmental microenvironments.

Breath measurements offer the potential for a direct and noninvasive evaluation of human exposure to volatile organic compounds (VOCs) in the environments in which people live and work. This research study was conducted to further evaluate and develop the potential of this exposure assessment methodology. Several people were exposed to the atmosphere in six microenvironments for several hours. Air concentrations of VOCs were measured during these exposures and breath samples were collected and analyzed at multiple time points after the exposure to evaluate elimination kinetics for 21 VOCs. A new alveolar breath collection technique was applied. Elimination half-lives were estimated using a mono- and bi-exponential model. The alveolar breath collection and analysis methodology proved to be very useful for collecting many samples in short time intervals and this capability was very important for more accurately describing the initial phase of the decay curves. Breath decay curves were generated from samples collected over a four hour period after exposure for 21 of 24 target VOCs. A biexponential function generally provided a better fit for the decay data than did the monoexponential function, supporting a multi-compartment uptake and elimination model for the human body.

Air Pollutants↗
PubMed1991

Effect of dry-cleaned clothes on tetrachloroethylene levels in indoor air, personal air, and breath for residents of several New Jersey homes.

Several volatile organic compounds, including tetrachloroethylene, have been found to be nearly ubiquitous in residential indoor environments during previous TEAM studies. Eleven homes in New Jersey were monitored over three or five days to examine the effect of bringing freshly dry-cleaned clothes into the home on indoor air levels and personal exposures to tetrachloroethylene. Indoor air, personal air, and breath concentrations were measured over multiple 12-hrs periods before and after dry-cleaned clothes were introduced into nine of the homes. No dry-cleaned clothes were introduced into the two remaining homes. Outdoor air tetrachloroethylene concentrations were measured at six of the eleven homes. Indoor/outdoor concentration ratios and source strengths were calculated at the six homes with outdoor measurements. Elevated indoor air levels and human exposures to tetrachloroethylene were measured at seven of the nine homes with dry-cleaned clothes. Indoor air concentrations reached 300 micrograms/m3 in one home and elevated indoor levels persisted for at least 48 hrs in all seven homes. Indoor/outdoor tetrachloroethylene concentration ratios exceeded 100 for the four homes with both dry-cleaned clothes and outdoor measurements. Maximum source strengths ranged from 16 to 69 mg/hr in these homes and did not directly correspond to the number of dry-cleaned garments brought into the home. Breath levels of tetrachloroethylene increased two to six-fold for participants living in seven homes with increased indoor air levels. Indoor air, personal air, and breath tetrachloroethylene concentrations were significantly related (0.05 level) to the number of garments introduced divided by the home volume.

Air Pollutants↗
PubMed1990

Characterization of polyimide sorbents by using tracer pulse chromatography.

A modification of tracer pulse chromatography was used to rapidly evaluate four novel polyimide sorbents for use in air sampling. This technique utilized probe molecules with differenet functional groups to evaluate the surface retention characteristics when the sorbents were highly loaded by these chemicals and humidity. The evaluation of sorbents indicated the polymer subunits of each must have multiple sorption sites which is consistent with their chemical makeup. Some comparisons between the polyimides and Tenax-GC were made.

Chromatography, Liquid↗
PubMed1989

Polychlorinated biphenyl congeners in adipose tissue lipid and serum of past and present transformer repair workers and a comparison group.

The concentrations of individual PCB's were determined in both serum and adipose tissue lipid from 35 transformer repair workers currently exposed to PCBs, mainly Aroclor 1260, 17 previous transformer repair workers, and 56 comparison workers never occupationally exposed to PCBs. The analysis used fused-silica capillary gas chromatography with electron capture detector (FSCGC/ECD) and FSCGC with negative ion chemical ionization mass spectrometry to verify PCB congener levels. Eighty-nine PCB peaks were identified and confirmed. More congeners were detected in adipose tissue. In serum approximately 50% of peaks were below the level of detection. Statistical techniques to account for left and interval censoring allowed comparison of concentration distributions even where data were incomplete. We found that unquantifiable levels were unlikely to contribute substantially to the true values for total [PCBs] over and beyond the contribution of the measured values. However, the total serum [PCBs] determined by FSCGC/ECD greatly exceeded that from standard packed cell gas chromatography (PCGC/ECD). The underestimation was less marked for adipose samples. In serum the total [PCBs] was highest in currently exposed workers and lowest in unexposed workers, with past-exposed workers clearly intermediate. In adipose tissue [PCBs] in the currently exposed group was much higher than in the other two groups, in whom the distribution of results was broadly similar. In all worker groups hexachlorinated and heptachlorinated species predominated followed by octachlorinated and pentachlorinated. The relative distribution of individual PCB congeners in the three groups was similar although the amounts varied. The seven major peaks in serum and adipose tissue were 2,3,5,6,3',4',5'/2,3,4,5,2',4',5' hepta-CB; 2,3,4,2',3',5' hexa-CB; 2,4,6,3',4',5'/2,4,5,2',4',5'/2,3,4,5,2',5' hexa-CB; 2,3,4,5,2',3',4' hepta-CB; 2,3,4,5,2',3',5',6'/2,3,4,5,6,2',3',5', octa-CB; 2,4,5,3',4',/3,4,5,2',3' penta-CB; and 2,3,4,2',3',4'/2,3,5,6,2',4',5'/2,3,4,5,2',4',6' multi-CB. The distribution of PCB peaks in our populations differs from that in capacitor workers (exposed to less highly chlorinated PCBs) and from Yu-Cheng patients suggesting differing toxic potentials from PCBs in these three circumstances.

Adipose Tissue↗
PubMed1989

The influence of personal activities on exposure to volatile organic compounds.

Seven persons volunteered to perform 25 common activities thought to increase personal exposure to volatile organic chemicals (VOCs) during a 3-day monitoring period. Personal, indoor, and outdoor air samples were collected on Tenax cartridges three times per day (evening, overnight, and daytime) and analyzed by GC-MS for 17 target VOCs. Samples of exhaled breath were also collected before and after each monitoring period. About 20 activities resulted in increasing exposure to one or more of the target VOCs, often by factors of 10, sometimes by factors of 100, compared to exposures during the sleep period. These concentrations were far above the highest observed outdoor concentrations during the length of the study. Breath levels were often significantly correlated with previous personal exposures. Major exposures were associated with use of deodorizers (p-dichlorobenzene); washing clothes and dishes (chloroform); visiting a dry cleaners (1,1,1-trichloroethane, tetrachloroethylene); smoking (benzene, styrene); cleaning a car engine (xylenes, ethylbenzene, tetrachloroethylene); painting and using paint remover (n-decane, n-undecane); and working in a scientific laboratory (many VOCs). Continuously elevated indoor air levels of p-dichlorobenzene, trichloroethylene, 1,1,1-trichloroethane, carbon tetrachloride, decane, and undecane were noted in several homes and attributed to unknown indoor sources. Measurements of exhaled breath suggested biological residence times in tissue of 12-18 hr and 20-30 hr for 1,1,1-trichloroethane and p-dichlorobenzene, respectively.

Activities of Daily Living↗
PubMed1987

Influence of serum cholesterol and albumin on partitioning of PCB congeners between human serum and adipose tissue.

The influence of serum lipids and proteins on partitioning of individual polychlorinated biphenyl (PCB) congener peaks between human serum and adipose tissue lipid was assessed using regression analysis. Subjects were 55 repair workers who were either currently or previously exposed, and 56 comparison workers without occupational exposure to PCBs. Seven congeners (2,4,5,4'-tetra CB, 2,3,5,2',3',6'-hexa CB, 2,3,4,2',3',6'-hexa CB, 2,3,4,2',4',5'-hexa CB, 3,4,5,3',4'-penta CB, 2,3,4,5,2',3',4'-hepta CB, and 2,3,4,5,2',3',4',5'-octa CB) which had been quantified in both serum and adipose tissue in at least one-third of the total study population were selected for evaluation. Initially the crude correlations between the serum PCB and certain candidate variables were assessed; more than one congener was correlated with serum cholesterol, albumin, triglycerides, low-density lipoproteins, very low-density lipoproteins, age, body fat content, and average servings of fish per day. Stepwise regression of log serum congener concentration on log adipose congener concentration and these variables was performed. Only cholesterol, albumin, and average servings of fish per day were significant for at least one congener peak. Congeners behaved in two groups, depending on their order of chromatographic elution. For 2,4,5,4'-tetra CB, 2,3,5,2',3',6'-hexa CB, and 2,3,4,2',3',6'-hexa CB, log serum concentration was not significantly correlated with log adipose congener concentration, and there was no consistent pattern for significant candidate variables. For congeners 2,3,4,2',4',5'-hexa CB, 3,4,5,3',4'-penta CB, 2,3,4,5,2',3',4'-hepta CB, and 2,3,4,5,2',3',4',5'-octa CB, log serum congener concentration was consistently significantly correlated with log adipose congener concentration and serum cholesterol positively, and with serum albumin negatively. For these four congeners the explanations of variation (R2) in serum congener concentration using adipose congener concentration alone were 3, 23, 20, and 30%, respectively, and after adding cholesterol and albumin were 13, 56, 43, and 46%. Thus we conclude that serum cholesterol and albumin can influence the distribution or partition of PCBs between serum and adipose tissue.

Adipose Tissue↗
PubMed1987

Personal air exposures and breath concentrations of benzene and other volatile hydrocarbons for smokers and nonsmokers.

Personal air exposures and exhaled breath concentrations of 20 volatile organic compounds were measured for 198 smokers and 322 non-smokers in 5 U.S. cities (1980-84). Smokers showed significantly increased breath concentrations of six hydrocarbons: benzene, styrene, ethylbenzene, o-xylene, m + p-xylene, and octane. Homes with smokers had higher indoor air concentrations of the same compounds than homes without smokers during fall and winter. Passive smokers exposed at work had significantly higher levels of benzene and other aromatics in their breath than unexposed non-smokers.

Air Pollutants↗
PubMed1987

The TEAM (Total Exposure Assessment Methodology) Study: personal exposures to toxic substances in air, drinking water, and breath of 400 residents of New Jersey, North Carolina, and North Dakota.

EPA's TEAM Study has measured exposures to 20 volatile organic compounds in personal air, outdoor air, drinking water, and breath of approximately 400 residents of New Jersey, North Carolina, and North Dakota. All residents were selected by a probability sampling scheme to represent 128,000 inhabitants of Elizabeth and Bayonne, New Jersey, 131,000 residents of Greensboro, North Carolina, and 7000 residents of Devils Lake, North Dakota. Participants carried a personal monitor to collect two 12-hr air samples and gave a breath sample at the end of the day. Two consecutive 12-hr outdoor air samples were also collected on identical Tenax cartridges in the backyards of some of the participants. About 5000 samples were collected, of which 1500 were quality control samples. Ten compounds were often present in personal air and breath samples at all locations. Personal exposures were consistently higher than outdoor concentrations for these chemicals and were sometimes 10 times the outdoor concentrations. Indoor sources appeared to be responsible for much of the difference. Breath concentrations also often exceeded outdoor concentrations and correlated more strongly with personal exposures than with outdoor concentrations. Some activities (smoking, visiting dry cleaners or service stations) and occupations (chemical, paint, and plastics plants) were associated with significantly elevated exposures and breath levels for certain toxic chemicals. Homes with smokers had significantly increased benzene and styrene levels in indoor air. Residence near major point sources did not affect exposure.

Air Pollutants, Occupational↗
PubMed1985

Recent advances in the analysis of polychlorinated biphenyls in environmental and biological media.

Analytical advances in the detection, identification and quantification of polychlorinated biphenyl isomers (PCBs) are reviewed. High-resolution gas chromatography, with specific reference to capillary column development and support "phases", methodologies, detector systems and the comparative advantages and limitations of each combination, is covered. Problems associated with instrument calibration, general non-availability of primary PCB standards and the use of secondary standards are discussed. Typical applications of these newer methods to environmental, biological and process stream samples are presented.

Aroclors↗
PubMed1985

Breath sampling.

Explore the source record for details and available documents.

Air Pollutants↗
PubMed1980

Method for analysis of polybrominated biphenyls by gas chromatography mass spectrometry.

Gas chromatography using a short packed column (45 cm, 0.2 cm i.d., 2% OV-101 on Gas-Chrom Q) with mass spectrometric detection in the selected ion monitoring mode has been found satisfactory for the analysis of lower as well as higher polybrominated biphenyls. Acceptable sensitivity (< 1 ng) may be achieved for this method by focusing selectively at either the low (m/z 20-600) or the high m/z 600-1000) range of the quadrupole filter (low range for mono- through hexabromobiphenyl, high range for hexa- through decabromobiphenyl). A tuning technique has been developed for low range and high range polybrominated biphenyls using the ion abundances of perfluorotributylamine as a standard. Standard ions for the quantitation of mono- through decabromo-biphenyls were selected and validated. The technique was applied to the analysis of a variety of environmental samples.

Animals↗