Sample records for air samples revealed

  1. Diagnosing AIRS Sampling with CloudSat Cloud Classes

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric; Yue, Qing; Guillaume, Alexandre; Kahn, Brian

    2011-01-01

    AIRS yield and sampling vary with cloud state. Careful utilization of collocated multiple satellite sensors is necessary. Profile differences between AIRS and ECMWF model analyses indicate that AIRS has high sampling and excellent accuracy for certain meteorological conditions. Cloud-dependent sampling biases may have large impact on AIRS L2 and L3 data in climate research. MBL clouds / lower tropospheric stability relationship is one example. AIRS and CloudSat reveal a reasonable climatology in the MBL cloud regime despite limited sampling in stratocumulus. Thermodynamic parameters such as EIS derived from AIRS data map these cloud conditions successfully. We are working on characterizing AIRS scenes with mixed cloud types.

  2. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Air sampling. 61.34 Section 61.34... sampling. (a) Stationary sources subject to § 61.32(b) shall locate air sampling sites in accordance with a... concentrations calculated within 30 days after filters are collected. Records of concentrations at all sampling...

  3. Air sampling with solid phase microextraction

    NASA Astrophysics Data System (ADS)

    Martos, Perry Anthony

    There is an increasing need for simple yet accurate air sampling methods. The acceptance of new air sampling methods requires compatibility with conventional chromatographic equipment, and the new methods have to be environmentally friendly, simple to use, yet with equal, or better, detection limits, accuracy and precision than standard methods. Solid phase microextraction (SPME) satisfies the conditions for new air sampling methods. Analyte detection limits, accuracy and precision of analysis with SPME are typically better than with any conventional air sampling methods. Yet, air sampling with SPME requires no pumps, solvents, is re-usable, extremely simple to use, is completely compatible with current chromatographic equipment, and requires a small capital investment. The first SPME fiber coating used in this study was poly(dimethylsiloxane) (PDMS), a hydrophobic liquid film, to sample a large range of airborne hydrocarbons such as benzene and octane. Quantification without an external calibration procedure is possible with this coating. Well understood are the physical and chemical properties of this coating, which are quite similar to those of the siloxane stationary phase used in capillary columns. The log of analyte distribution coefficients for PDMS are linearly related to chromatographic retention indices and to the inverse of temperature. Therefore, the actual chromatogram from the analysis of the PDMS air sampler will yield the calibration parameters which are used to quantify unknown airborne analyte concentrations (ppb v to ppm v range). The second fiber coating used in this study was PDMS/divinyl benzene (PDMS/DVB) onto which o-(2,3,4,5,6- pentafluorobenzyl) hydroxylamine (PFBHA) was adsorbed for the on-fiber derivatization of gaseous formaldehyde (ppb v range), with and without external calibration. The oxime formed from the reaction can be detected with conventional gas chromatographic detectors. Typical grab sampling times were as small as 5 seconds

  4. Inertial impaction air sampling device

    DOEpatents

    Dewhurst, Katharine H.

    1990-01-01

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry.

  5. Inertial impaction air sampling device

    DOEpatents

    Dewhurst, K.H.

    1990-05-22

    An inertial impactor is designed which is to be used in an air sampling device for collection of respirable size particles in ambient air. The device may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  6. Inertial impaction air sampling device

    DOEpatents

    Dewhurst, K.H.

    1987-12-10

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  7. Air Sampling Filter

    NASA Technical Reports Server (NTRS)

    1980-01-01

    General Metal Works' Accu-Vol is a high-volume air sampling system used by many government agencies to monitor air quality for pollution control purposes. Procedure prevents possible test-invalidating contamination from materials other than particulate pollutants, caused by manual handling or penetration of windblown matter during transit, a cassette was developed in which the filter is sealed within a metal frame and protected in transit by a snap-on aluminum cover, thus handled only under clean conditions in the laboratory.

  8. Monitoring airborne fungal spores in an experimental indoor environment to evaluate sampling methods and the effects of human activity on air sampling.

    PubMed Central

    Buttner, M P; Stetzenbach, L D

    1993-01-01

    Aerobiological monitoring was conducted in an experimental room to aid in the development of standardized sampling protocols for airborne microorganisms in the indoor environment. The objectives of this research were to evaluate the relative efficiencies of selected sampling methods for the retrieval of airborne fungal spores and to determine the effect of human activity on air sampling. Dry aerosols containing known concentrations of Penicillium chrysogenum spores were generated, and air samples were taken by using Andersen six-stage, Surface Air System, Burkard, and depositional samplers. The Andersen and Burkard samplers retrieved the highest numbers of spores compared with the measurement standard, an aerodynamic particle sizer located inside the room. Data from paired samplers demonstrated that the Andersen sampler had the highest levels of sensitivity and repeatability. With a carpet as the source of P. chrysogenum spores, the effects of human activity (walking or vacuuming near the sampling site) on air sampling were also examined. Air samples were taken under undisturbed conditions and after human activity in the room. Human activity resulted in retrieval of significantly higher concentrations of airborne spores. Surface sampling of the carpet revealed moderate to heavy contamination despite relatively low airborne counts. Therefore, in certain situations, air sampling without concomitant surface sampling may not adequately reflect the level of microbial contamination in indoor environments. PMID:8439150

  9. Air sampling workshop: October 24-25, 1978

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1979-06-01

    A two-day workshop was held in October 1978 on air sampling strategies for the occupational environment. Strategies comprise the elements of implementing an air sampling program including deciding on the extent of sampling, selecting appropriate types of measurement, placing sampling instruments properly, and interpreting sample results correctly. All of these elements are vital in the reliable assessment of occupational exposures yet their coverage in the industrial hygiene literature is meager. Although keyed to a few introductory topics, the agenda was sufficiently informal to accommodate extemporaneous discussion on any subject related to sampling strategies. Questions raised during the workshop mirror themore » status of air sampling strategy as much as the factual information that was presented. It may be concluded from the discussion and questions that air sampling strategy is an elementary state and urgently needs concerted attention from the industrial hygiene profession.« less

  10. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 9 2012-07-01 2012-07-01 false Air sampling. 61.34 Section 61.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34 Air...

  11. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 9 2013-07-01 2013-07-01 false Air sampling. 61.34 Section 61.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34 Air...

  12. Adaptive Sampling for Urban Air Quality through Participatory Sensing

    PubMed Central

    Zeng, Yuanyuan; Xiang, Kai

    2017-01-01

    Air pollution is one of the major problems of the modern world. The popularization and powerful functions of smartphone applications enable people to participate in urban sensing to better know about the air problems surrounding them. Data sampling is one of the most important problems that affect the sensing performance. In this paper, we propose an Adaptive Sampling Scheme for Urban Air Quality (AS-air) through participatory sensing. Firstly, we propose to find the pattern rules of air quality according to the historical data contributed by participants based on Apriori algorithm. Based on it, we predict the on-line air quality and use it to accelerate the learning process to choose and adapt the sampling parameter based on Q-learning. The evaluation results show that AS-air provides an energy-efficient sampling strategy, which is adaptive toward the varied outside air environment with good sampling efficiency. PMID:29099766

  13. Passive air sampling theory for semivolatile organic compounds.

    PubMed

    Bartkow, Michael E; Booij, Kees; Kennedy, Karen E; Müller, Jochen F; Hawker, Darryl W

    2005-07-01

    The mathematical modelling underlying passive air sampling theory can be based on mass transfer coefficients or rate constants. Generally, these models have not been inter-related. Starting with basic models, the exchange of chemicals between the gaseous phase and the sampler is developed using mass transfer coefficients and rate constants. Importantly, the inter-relationships between the approaches are demonstrated by relating uptake rate constants and loss rate constants to mass transfer coefficients when either sampler-side or air-side resistance is dominating chemical exchange. The influence of sampler area and sampler volume on chemical exchange is discussed in general terms and as they relate to frequently used parameters such as sampling rates and time to equilibrium. Where air-side or sampler-side resistance dominates, an increase in the surface area of the sampler will increase sampling rates. Sampling rates are not related to the sampler/air partition coefficient (K(SV)) when air-side resistance dominates and increase with K(SV) when sampler-side resistance dominates.

  14. Double-layer Tedlar bags: a means to limit humidity evolution of air samples and to dry humid air samples.

    PubMed

    Cariou, Stephane; Guillot, Jean-Michel

    2006-01-01

    Tedlar bags, which are widely used to collect air samples, especially VOCs and odorous atmospheres, can allow humidity to diffuse when relative humidity levels differ between the inside and outside. Starting with dry air inside the bag and humid air outside, we monitored equilibrium times under several conditions showing the evolution and influence of collected volumes and exposed surfaces. A double-film Tedlar bag was made, to limit the impact of external humidity on a sample at low humidity level. With the addition of a drying agent between both films, the evolution of humidity of a sample can be stopped for several hours. When a VOC mixture was monitored in a humid atmosphere, humidity was decreased but no significant evolution of VOC concentrations was observed.

  15. Innovations in air sampling to detect plant pathogens

    PubMed Central

    West, JS; Kimber, RBE

    2015-01-01

    Many innovations in the development and use of air sampling devices have occurred in plant pathology since the first description of the Hirst spore trap. These include improvements in capture efficiency at relatively high air-volume collection rates, methods to enhance the ease of sample processing with downstream diagnostic methods and even full automation of sampling, diagnosis and wireless reporting of results. Other innovations have been to mount air samplers on mobile platforms such as UAVs and ground vehicles to allow sampling at different altitudes and locations in a short space of time to identify potential sources and population structure. Geographical Information Systems and the application to a network of samplers can allow a greater prediction of airborne inoculum and dispersal dynamics. This field of technology is now developing quickly as novel diagnostic methods allow increasingly rapid and accurate quantifications of airborne species and genetic traits. Sampling and interpretation of results, particularly action-thresholds, is improved by understanding components of air dispersal and dilution processes and can add greater precision in the application of crop protection products as part of integrated pest and disease management decisions. The applications of air samplers are likely to increase, with much greater adoption by growers or industry support workers to aid in crop protection decisions. The same devices are likely to improve information available for detection of allergens causing hay fever and asthma or provide valuable metadata for regional plant disease dynamics. PMID:25745191

  16. Presence of organophosphorus pesticide oxygen analogs in air samples

    NASA Astrophysics Data System (ADS)

    Armstrong, Jenna L.; Fenske, Richard A.; Yost, Michael G.; Galvin, Kit; Tchong-French, Maria; Yu, Jianbo

    2013-02-01

    A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and laboratory experiments were used to examine artificial formation of chlorpyrifos-oxon using OSHA Versatile Sampling (OVS) tubes as recommended by NIOSH method 5600. Additionally, we compared expected chlorpyrifos-oxon attributable to artificial transformation to observed chlorpyrifos-oxon in field samples from a 2008 Washington State Department of Health air monitoring study using non-parametric statistical methods. The amount of artificially transformed oxon was then modeled to determine the amount of oxon present in the environment. Toxicity equivalency factors (TEFs) for chlorpyrifos-oxon were used to calculate chlorpyrifos-equivalent air concentrations. The results demonstrate that the NIOSH-recommended sampling matrix (OVS tubes with XAD-2 resin) was found to artificially transform up to 30% of chlorpyrifos to chlorpyrifos-oxon, with higher percentages at lower concentrations (<30 ng m-3) typical of ambient or residential levels. Overall, the 2008 study data had significantly greater oxon than expected by artificial transformation, but the exact amount of environmental oxon in air remains difficult to quantify with the current sampling method. Failure to conduct laboratory analysis for chlorpyrifos-oxon may result in underestimation of total pesticide concentration when using XAD-2 resin matrices for occupational or residential sampling. Alternative methods that can accurately measure both OP pesticides and their oxygen analogs should be used for air sampling, and a toxicity

  17. Analysis of EPA and DOE WIPP Air Sampling Data

    EPA Pesticide Factsheets

    During the April 2014 EPA visit to WIPP, EPA co-located four ambient air samplers with existing Department of Energy (DOE) ambient air samplers to independently corroborate DOE's reported air sampling results.

  18. [Microbial air monitoring in operating theatre: active and passive samplings].

    PubMed

    Pasquarella, C; Masia, M D; Nnanga, Nga; Sansebastiano, G E; Savino, A; Signorelli, C; Veronesi, L

    2004-01-01

    Microbial air contamination was evaluated in 11 operating theatres using active and passive samplings. SAS (Surface Air System) air sampling was used to evaluate cfu/m3 and settle plates were used to measure the index of microbial air contamination (IMA). Samplings were performed at the same time on three different days, at three different times (before, during and after the surgical activity). Two points were monitored (patient area and perimeter of the operating theatre). Moreover, the cfu/m3 were evaluated at the air inlet of the conditioner system. 74.7% of samplings performed at the air inlet and 66.7% of the samplings performed at the patient area before the beginning of the surgical activity (at rest) exceeded the 35 cfu/m3 used as threshold value. 100% of IMA values exceeded the threshold value of 5. Using both active and passive sampling, the microbial contamination was shown to increase significantly during activity. The cfu values were higher at the patient area than at the perimeter of the operating theatre. Mean values of the cfu/m3 during activity at the patient area ranged from a minimum of 61+/-41 cfu/m3 to a maximum of 242+/-136 cfu/m3; IMA values ranged from a minimum of 19+/-10 to a maximum of 129+/-60. 15.2% of samplings performed at the patient area using SAS and 75.8% of samplings performed using settle plates exceeded the threshold values of 180 cfu/m3 and 25 respectively, with a significant difference of the percentages. The highest values were found in the operating theatre with inadequate structural and managerial conditions. These findings confirm that the microbiological quality of air may be considered a mirror of the hygienic conditions of the operating theatre. Settle plates proved to be more sensitive in detecting the increase of microbial air contamination related to conditions that could compromise the quality of the air in operating theatres.

  19. A simple novel device for air sampling by electrokinetic capture.

    PubMed

    Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra; Frazier, Angel; Hampton-Marcell, Jarrad; Gilbert, Jack A

    2015-12-27

    A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrode assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87 %, with the reference filter taken as "gold standard." Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. The performance of the device is

  20. Uncertainties in monitoring of SVOCs in air caused by within-sampler degradation during active and passive air sampling

    NASA Astrophysics Data System (ADS)

    Melymuk, Lisa; Bohlin-Nizzetto, Pernilla; Prokeš, Roman; Kukučka, Petr; Přibylová, Petra; Vojta, Šimon; Kohoutek, Jiří; Lammel, Gerhard; Klánová, Jana

    2017-10-01

    Degradation of semivolatile organic compounds (SVOCs) occurs naturally in ambient air due to reactions with reactive trace gases (e.g., ozone, NOx). During air sampling there is also the possibility for degradation of SVOCs within the air sampler, leading to underestimates of ambient air concentrations. We investigated the possibility of this sampling artifact in commonly used active and passive air samplers for seven classes of SVOCs, including persistent organic pollutants (POPs) typically covered by air monitoring programs, as well as SVOCs of emerging concern. Two active air samplers were used, one equipped with an ozone denuder and one without, to compare relative differences in mass of collected compounds. Two sets of passive samplers were also deployed to determine the influence of degradation during longer deployment times in passive sampling. In active air samplers, comparison of the two sampling configurations suggested degradation of particle-bound polycyclic aromatic hydrocarbons (PAHs), with concentrations up to 2× higher in the denuder-equipped sampler, while halogenated POPs did not have clear evidence of degradation. In contrast, more polar, reactive compounds (e.g., organophosphate esters and current use pesticides) had evidence of losses in the sampler with denuder. This may be caused by the denuder itself, suggesting sampling bias for these compounds can be created when typical air sampling apparatuses are adapted to limit degradation. Passive air samplers recorded up to 4× higher concentrations when deployed for shorter consecutive sampling periods, suggesting that within-sampler degradation may also be relevant in passive air monitoring programs.

  1. 30 CFR 90.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved sampling devices; operation; air... LABOR COAL MINE SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-COAL MINERS WHO HAVE EVIDENCE OF THE DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.205 Approved sampling devices; operation; air flowrate...

  2. Convair F-106B Delta Dart with Air Sampling Equipment

    NASA Image and Video Library

    1974-04-21

    The National Aeronautics and Space Administration (NASA) Lewis Research Center’s Convair F-106B Delta Dart equipped with air sampling equipment in the mid-1970s. NASA Lewis created and managed the Global Air Sampling Program (GASP) in 1972 in partnership with several airline companies. NASA researchers used the airliners’ Boeing 747 aircraft to gather air samples to determine the amount of pollution present in the stratosphere. Private companies developed the air sampling equipment for the GASP program, and Lewis created a particle collector. The collector was flight tested on NASA Lewis’ F-106B in the summer of 1973. The sampling equipment was automatically operated once the proper altitude was achieved. The sampling instruments collected dust particles in the air so their chemical composition could be analyzed. The equipment analyzed one second’s worth of data at a time. The researchers also monitored carbon monoxide, monozide, ozone, and water vapor. The 747 flights began in December 1974 and soon included four airlines flying routes all over the globe. The F-106B augmented the airline data with sampling of its own, seen here. It gathered samples throughout this period from locations such as New Mexico, Texas, Michigan, and Ohio. In July 1977 the F-106B flew eight GASP flights in nine days over Alaska to supplement the earlier data gathered by the airlines.

  3. Systematic Evaluation of Aggressive Air Sampling for Bacillus ...

    EPA Pesticide Factsheets

    Report The primary objectives of this project were to evaluate the Aggressive Air Sampling (AAS) method compared to currently used surface sampling methods and to determine if AAS is a viable option for sampling Bacillus anthracis spores.

  4. A simple novel device for air sampling by electrokinetic capture

    DOE PAGES

    Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra; ...

    2015-12-27

    A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrodemore » assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87%, with the reference filter taken as “gold standard.” Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. In conclusion, the performance of

  5. A simple novel device for air sampling by electrokinetic capture

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra

    A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrodemore » assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87%, with the reference filter taken as “gold standard.” Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. In conclusion, the performance of

  6. Can car air filters be useful as a sampling medium for air pollution monitoring purposes?

    PubMed

    Katsoyiannis, Athanasios; Birgul, Askin; Ratola, Nuno; Cincinelli, Alessandra; Sweetman, Andy J; Jones, Kevin C

    2012-11-01

    Urban air quality and real human exposure to chemical environmental stressors is an issue of high scientific and political interest. In an effort to find innovative and inexpensive means for air quality monitoring, the ability of car engine air filters (CAFs) to act as efficient samplers collecting street level air, to which people are exposed to, was tested. In particular, in the case of taxis, air filters are replaced after regular distances, the itineraries are almost exclusively urban, cruising mode is similar and, thus, knowledge of the air flow can provide with an integrated city air sample. The present pilot study focused on polycyclic aromatic hydrocarbons (PAHs), the most important category of organic pollutants associated with traffic emissions. Concentrations of ΣPAHs in CAFs ranged between 650 and 2900 μg CAF(-1), with benzo[b]fluoranthene, benzo[k]fluoranthene and indeno[123-cd]pyrene being the most abundant PAHs. Benzo[a]pyrene (BaP) ranged between 110 and 250 μg CAF(-1), accounting regularly for 5-15% of the total carcinogenic PAHs. The CAF PAH loads were used to derive road-level atmospheric PAH concentrations from a standard formula relating to the CAF air flow. Important parameters/assumptions for these estimates are the cruising speed and the exposure duration of each CAF. Based on information obtained from the garage experts, an average 'sampled air volume' of 48,750 m(3) per CAF was estimated, with uncertainty in this calculation estimated to be about a factor of 4 between the two extreme scenarios. Based on this air volume, ΣPAHs ranged between 13 and 56 ng m(-3) and BaP between 2.1 and 5.0 ng m(-3), suggesting that in-traffic BaP concentrations can be many times higher than the limit values set by the UK (0.25 ng m(-3)) and the European Union (1.0 ng m(-3)), or from active sampling stations normally cited on building roof tops or far from city centres. Notwithstanding the limitations of this approach, the very low cost, the continuous

  7. Air Sample Conditioner Helps the Waste Treatment Plant Meet Emissions Standards

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Glissmeyer, John A.; Flaherty, Julia E.; Pekour, Mikhail S.

    2014-12-02

    The air in three of the Hanford Site Waste Treatment and Immobilization Plant (WTP) melter off-gas discharge stacks will be hot and humid after passing through the train of emission abatement equipment. The off-gas temperature and humidity levels will be incompatible with the airborne emissions monitoring equipment required for this type of stack. To facilitate sampling from these facilities, an air sample conditioner system will be installed to introduce cool, dry air into the sample stream to reduce the temperature and dew point. This will avoid thermal damage to the instrumentation and problematic condensation. The complete sample transport system mustmore » also deliver at least 50% of the particles in the sample airstream to the sample collection and on-line analysis equipment. The primary components of the sample conditioning system were tested in a laboratory setting. The sample conditioner itself is based on a commercially-available porous tube filter design. It consists of a porous sintered metal tube inside a coaxial metal jacket. The hot gas sample stream passes axially through the porous tube, and the dry, cool air is injected into the jacket and through the porous wall of the inner tube, creating an effective sample diluter. The dilution and sample air mix along the entire length of the porous tube, thereby simultaneously reducing the dew point and temperature of the mixed sample stream. Furthermore, because the dilution air enters through the porous tube wall, the sample stream does not come in contact with the porous wall and particle deposition is reduced in this part of the sampling system. Tests were performed with an environmental chamber to supply air with the temperature and humidity needed to simulate the off-gas conditions. Air from the chamber was passed through the conditioning system to test its ability to reduce the temperature and dew point of the sample stream. To measure particle deposition, oil droplets in the range of 9 to 11

  8. A new device for dynamic sampling of radon in air

    NASA Astrophysics Data System (ADS)

    Lozano, J. C.; Escobar, V. Gómez; Tomé, F. Vera

    2000-08-01

    A new system is proposed for the active sampling of radon in air, based on the well-known property of activated charcoal to retain radon. Two identical carbon-activated cartridges arranged in series remove the radon from the air being sampled. The air passes first through a desiccant cell and then the carbon cartridges for short sampling times using a low-flow pump. The alpha activity for each cartridge is determined by a liquid scintillation counting system. The cartridge is placed in a holder into a vial that also contains the appropriate amount of scintillation cocktail, in a way that avoids direct contact between cocktail and charcoal. Once dynamic equilibrium between the phases has been reached, the vials can be counted. Optimum sampling conditions concerning flow rates and sampling times are determined. Using those conditions, the method was applied to environmental samples, straightforwardly providing good results for very different levels of activity.

  9. Air bubbles and hemolysis of blood samples during transport by pneumatic tube systems.

    PubMed

    Mullins, Garrett R; Bruns, David E

    2017-10-01

    Transport of blood samples through pneumatic tube systems (PTSs) generates air bubbles in transported blood samples and, with increasing duration of transport, the appearance of hemolysis. We investigated the role of air-bubble formation in PTS-induced hemolysis. Air was introduced into blood samples for 0, 1, 3 or 5min to form air bubbles. Hemolysis in the blood was assessed by (H)-index, lactate dehydrogenase (LD) and potassium in plasma. In an effort to prevent PTS-induced hemolysis, blood sample tubes were completely filled, to prevent air bubble formation, and compared with partially filled samples after PTS transport. We also compared hemolysis in anticoagulated vs clotted blood subjected to PTS transport. As with transport through PTSs, the duration of air bubble formation in blood by a gentle stream of air predicted the extent of hemolysis as measured by H-index (p<0.01), LD (p<0.01), and potassium (p<0.02) in plasma. Removing air space in a blood sample prevented bubble formation and fully protected the blood from PTS-induced hemolysis (p<0.02 vs conventionally filled collection tube). Clotted blood developed less foaming during PTS transport and was partially protected from hemolysis vs anticoagulated blood as indicated by lower LD (p<0.03) in serum than in plasma after PTS sample transport. Prevention of air bubble formation in blood samples during PTS transport protects samples from hemolysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Comparison of stationary and personal air sampling with an ...

    EPA Pesticide Factsheets

    Manganese (Mn) is ubiquitous in the environment and essential for normal growth and development, yet excessive exposure can lead to impairments in neurological function. This study modeled ambient Mn concentrations as an alternative to stationary and personal air sampling to assess exposure for children enrolled in the Communities Actively Researching Exposure Study in Marietta, OH. Ambient air Mn concentration values were modeled using US Environmental Protection Agency’s Air Dispersion Model AERMOD based on emissions from the ferromanganese refinery located in Marietta. Modeled Mn concentrations were compared with Mn concentrations from a nearby stationary air monitor. The Index of Agreement for modeled versus monitored data was 0.34 (48 h levels) and 0.79 (monthly levels). Fractional bias was 0.026 for 48 h levels and −0.019 for monthly levels. The ratio of modeled ambient air Mn to measured ambient air Mn at the annual time scale was 0.94. Modeled values were also time matched to personal air samples for 19 children. The modeled values explained a greater degree of variability in personal exposures compared with time-weighted distance from the emission source. Based on these results modeled Mn concentrations provided a suitable approach for assessing airborne Mn exposure in this cohort. The purpose of the study was to investigate the use of air-dispersion modeling as an approach to exposure assessment for ambient manganese.

  11. APPLICATION OF SEMIPERMEABLE MEMBRANE DEVICES TO INDOOR AIR SAMPLING

    EPA Science Inventory

    Semipermeable membrane devices (SPMDs) are a relatively new passive sampling technique for nonpolar organic compounds that have been extensively used for surface water sampling. A small body of literature indicates that SPMDs are also useful for air sampling. Because SPMDs ha...

  12. Interferometrically stable, enclosed, spinning sample cell for spectroscopic experiments on air-sensitive samples

    NASA Astrophysics Data System (ADS)

    Baranov, Dmitry; Hill, Robert J.; Ryu, Jisu; Park, Samuel D.; Huerta-Viga, Adriana; Carollo, Alexa R.; Jonas, David M.

    2017-01-01

    In experiments with high photon flux, it is necessary to rapidly remove the sample from the beam and to delay re-excitation until the sample has returned to equilibrium. Rapid and complete sample exchange has been a challenge for air-sensitive samples and for vibration-sensitive experiments. Here, a compact spinning sample cell for air and moisture sensitive liquid and thin film samples is described. The principal parts of the cell are a copper gasket sealed enclosure, a 2.5 in. hard disk drive motor, and a reusable, chemically inert glass sandwich cell. The enclosure provides an oxygen and water free environment at the 1 ppm level, as demonstrated by multi-day tests with sodium benzophenone ketyl radical. Inside the enclosure, the glass sandwich cell spins at ≈70 Hz to generate tangential speeds of 7-12 m/s that enable complete sample exchange at 100 kHz repetition rates. The spinning cell is acoustically silent and compatible with a ±1 nm rms displacement stability interferometer. In order to enable the use of the spinning cell, we discuss centrifugation and how to prevent it, introduce the cycle-averaged resampling rate to characterize repetitive excitation, and develop a figure of merit for a long-lived photoproduct buildup.

  13. Interferometrically stable, enclosed, spinning sample cell for spectroscopic experiments on air-sensitive samples.

    PubMed

    Baranov, Dmitry; Hill, Robert J; Ryu, Jisu; Park, Samuel D; Huerta-Viga, Adriana; Carollo, Alexa R; Jonas, David M

    2017-01-01

    In experiments with high photon flux, it is necessary to rapidly remove the sample from the beam and to delay re-excitation until the sample has returned to equilibrium. Rapid and complete sample exchange has been a challenge for air-sensitive samples and for vibration-sensitive experiments. Here, a compact spinning sample cell for air and moisture sensitive liquid and thin film samples is described. The principal parts of the cell are a copper gasket sealed enclosure, a 2.5 in. hard disk drive motor, and a reusable, chemically inert glass sandwich cell. The enclosure provides an oxygen and water free environment at the 1 ppm level, as demonstrated by multi-day tests with sodium benzophenone ketyl radical. Inside the enclosure, the glass sandwich cell spins at ≈70 Hz to generate tangential speeds of 7-12 m/s that enable complete sample exchange at 100 kHz repetition rates. The spinning cell is acoustically silent and compatible with a ±1 nm rms displacement stability interferometer. In order to enable the use of the spinning cell, we discuss centrifugation and how to prevent it, introduce the cycle-averaged resampling rate to characterize repetitive excitation, and develop a figure of merit for a long-lived photoproduct buildup.

  14. Air sampling unit for breath analyzers

    NASA Astrophysics Data System (ADS)

    Szabra, Dariusz; Prokopiuk, Artur; Mikołajczyk, Janusz; Ligor, Tomasz; Buszewski, Bogusław; Bielecki, Zbigniew

    2017-11-01

    The paper presents a portable breath sampling unit (BSU) for human breath analyzers. The developed unit can be used to probe air from the upper airway and alveolar for clinical and science studies. The BSU is able to operate as a patient interface device for most types of breath analyzers. Its main task is to separate and to collect the selected phases of the exhaled air. To monitor the so-called I, II, or III phase and to identify the airflow from the upper and lower parts of the human respiratory system, the unit performs measurements of the exhaled CO2 (ECO2) in the concentration range of 0%-20% (0-150 mm Hg). It can work in both on-line and off-line modes according to American Thoracic Society/European Respiratory Society standards. A Tedlar bag with a volume of 5 dm3 is mounted as a BSU sample container. This volume allows us to collect ca. 1-25 selected breath phases. At the user panel, each step of the unit operation is visualized by LED indicators. This helps us to regulate the natural breathing cycle of the patient. There is also an operator's panel to ensure monitoring and configuration setup of the unit parameters. The operation of the breath sampling unit was preliminarily verified using the gas chromatography/mass spectrometry (GC/MS) laboratory setup. At this setup, volatile organic compounds were extracted by solid phase microextraction. The tests were performed by the comparison of GC/MS signals from both exhaled nitric oxide and isoprene analyses for three breath phases. The functionality of the unit was proven because there was an observed increase in the signal level in the case of the III phase (approximately 40%). The described work made it possible to construct a prototype of a very efficient breath sampling unit dedicated to breath sample analyzers.

  15. Air and smear sample calculational tool for Fluor Hanford Radiological control

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    BAUMANN, B.L.

    2003-07-11

    A spreadsheet calculation tool was developed to automate the calculations performed for determining the concentration of airborne radioactivity and smear counting as outlined in HNF-13536, Section 5.2.7, ''Analyzing Air and Smear Samples''. This document reports on the design and testing of the calculation tool. Radiological Control Technicians (RCTs) will save time and reduce hand written and calculation errors by using an electronic form for documenting and calculating work place air samples. Current expectations are RCTs will perform an air sample and collect the filter or perform a smear for surface contamination. RCTs will then survey the filter for gross alphamore » and beta/gamma radioactivity and with the gross counts utilize either hand calculation method or a calculator to determine activity on the filter. The electronic form will allow the RCT with a few key strokes to document the individual's name, payroll, gross counts, instrument identifiers; produce an error free record. This productivity gain is realized by the enhanced ability to perform mathematical calculations electronically (reducing errors) and at the same time, documenting the air sample.« less

  16. Concentrations of particulates in ambient air, gaseous elementary mercury (GEM), and particulate-bound mercury (Hg(p)) at a traffic sampling site: a study of dry deposition in daytime and nighttime.

    PubMed

    Fang, Guor-Cheng; Lin, Yen-Heng; Chang, Chia-Ying; Zheng, Yu-Cheng

    2014-08-01

    In this investigation, the concentrations of particles in ambient air, gaseous elemental mercury (GEM), and particulate-bound mercury (Hg(p)) in total suspended particulates (TSP) as well as dry deposition at a (Traffic) sampling site at Hung-kuang were studied during the day and night in 2012. The results reveal that the mean concentrations of TSP in ambient air, GEM, and Hg(p) were 69.72 μg/m(3), 3.17, and 0.024 ng/m(3), respectively, at the Hung-kuang (Traffic) sampling site during daytime sampling periods. The results also reveal that the mean rates of dry deposition of particles from ambient air and Hg(p) were 145.20 μg/m(2) min and 0.022 ng/m(2) min, respectively, at the Hung-kuang (Traffic) sampling site during the daytime sampling period. The mean concentrations of TSP in ambient air, GEM, and Hg(p) were 60.56 μg/m(3), 2.74, and 0.018 ng/m(3), respectively, at the Hung-kuang (Traffic) sampling site during the nighttime sampling period. The mean rates of dry deposition of particles and Hg(p) from ambient air were 132.58 μg/m(2) min and 0.016 ng/m(2) min, respectively, at the Hung-kuang (Traffic) sampling site during the nighttime sampling period.

  17. Sorbent-based sampling methods for volatile and semi-volatile organic compounds in air Part 1: Sorbent-based air monitoring options.

    PubMed

    Woolfenden, Elizabeth

    2010-04-16

    Sorbent tubes/traps are widely used in combination with gas chromatographic (GC) analytical methods to monitor the vapour-phase fraction of organic compounds in air. Target compounds range in volatility from acetylene and freons to phthalates and PCBs and include apolar, polar and reactive species. Airborne vapour concentrations will vary depending on the nature of the location, nearby pollution sources, weather conditions, etc. Levels can range from low percent concentrations in stack and vent emissions to low part per trillion (ppt) levels in ultra-clean outdoor locations. Hundreds, even thousands of different compounds may be present in any given atmosphere. GC is commonly used in combination with mass spectrometry (MS) detection especially for environmental monitoring or for screening uncharacterised workplace atmospheres. Given the complexity and variability of organic vapours in air, no one sampling approach suits every monitoring scenario. A variety of different sampling strategies and sorbent media have been developed to address specific applications. Key sorbent-based examples include: active (pumped) sampling onto tubes packed with one or more sorbents held at ambient temperature; diffusive (passive) sampling onto sorbent tubes/cartridges; on-line sampling of air/gas streams into cooled sorbent traps; and transfer of air samples from containers (canisters, Tedlar) bags, etc.) into cooled sorbent focusing traps. Whichever sampling approach is selected, subsequent analysis almost always involves either solvent extraction or thermal desorption (TD) prior to GC(/MS) analysis. The overall performance of the air monitoring method will depend heavily on appropriate selection of key sampling and analytical parameters. This comprehensive review of air monitoring using sorbent tubes/traps is divided into 2 parts. (1) Sorbent-based air sampling option. (2) Sorbent selection and other aspects of optimizing sorbent-based air monitoring methods. The paper presents

  18. Detection of the urban release of a bacillus anthracis simulant by air sampling.

    PubMed

    Garza, Alexander G; Van Cuyk, Sheila M; Brown, Michael J; Omberg, Kristin M

    2014-01-01

    In 2005 and 2009, the Pentagon Force Protection Agency (PFPA) staged deliberate releases of a commercially available organic pesticide containing Bacillus amyloliquefaciens to evaluate PFPA's biothreat response protocols. In concert with, but independent of, these releases, the Department of Homeland Security sponsored experiments to evaluate the efficacy of commonly employed air and surface sampling techniques for detection of an aerosolized biological agent. High-volume air samplers were placed in the expected downwind plume, and samples were collected before, during, and after the releases. Environmental surface and personal air samples were collected in the vicinity of the high-volume air samplers hours after the plume had dispersed. The results indicate it is feasible to detect the release of a biological agent in an urban area both during and after the release of a biological agent using high-volume air and environmental sampling techniques.

  19. Detection of Legionella spp. by a nested-PCR assay in air samples of a wastewater treatment plant and downwind distances in Isfahan

    PubMed Central

    Mirzaee, Seyyed Abbas; Nikaeen, Mahnaz; Hajizadeh, Yaghob; Nabavi, BiBi Fatemeh; Hassanzadeh, Akbar

    2015-01-01

    Background: Wastewater contains a variety of pathogens and bio -aerosols generated during the wastewater treatment process, which could be a potential health risk for exposed individuals. This study was carried out to detect Legionella spp. in the bio -aerosols generated from different processes of a wastewater treatment plant (WWTP) in Isfahan, Iran, and the downwind distances. Materials and Methods: A total of 54 air samples were collected and analyzed for the presence of Legionella spp. by a nested- polymerase chain reaction (PCR) assay. A liquid impingement biosampler was used to capture bio -aerosols. The weather conditions were also recorded. Results: Legionella were detected in 6% of the samples, including air samples above the aeration tank (1/9), belt filter press (1/9), and 250 m downwind (1/9). Conclusion: The result of this study revealed the presence of Legionella spp. in air samples of a WWTP and downwind distance, which consequently represent a potential health risk to the exposed individuals. PMID:25802817

  20. Commander De Winne poses for a photo during Air Sampling

    NASA Image and Video Library

    2009-11-11

    ISS021-E-024700 (11 Nov. 2009) --- European Space Agency astronaut Frank De Winne, Expedition 21 commander, uses the Microbial Air Sampler kit (floating freely near De Winne) to obtain microbiology (bacterial & fungal) air samples in the Kibo laboratory of the International Space Station.

  1. Detection of Mycoplasma hyopneumoniae by Air Sampling with a Nested PCR Assay

    PubMed Central

    Stärk, Katharina D. C.; Nicolet, Jacques; Frey, Joachim

    1998-01-01

    This article describes the first successful detection of airborne Mycoplasma hyopneumoniae under experimental and field conditions with a new nested PCR assay. Air was sampled with polyethersulfone membranes (pore size, 0.2 μm) mounted in filter holders. Filters were processed by dissolution and direct extraction of DNA for PCR analysis. For the PCR, two nested pairs of oligonucleotide primers were designed by using an M. hyopneumoniae-specific DNA sequence of a repeated gene segment. A nested PCR assay was developed and used to analyze samples collected in eight pig houses where respiratory problems had been common. Air was also sampled from a mycoplasma-free herd. The nested PCR was highly specific and 104 times as sensitive as a one-step PCR. Under field conditions, the sampling system was able to detect airborne M. hyopneumoniae on 80% of farms where acute respiratory disease was present. No airborne M. hyopneumoniae was detected on infected farms without acute cases. The chance of successful detection was increased if air was sampled at several locations within a room and at a lower air humidity. PMID:9464391

  2. AirCore-HR: a high-resolution column sampling to enhance the vertical description of CH4 and CO2

    NASA Astrophysics Data System (ADS)

    Membrive, Olivier; Crevoisier, Cyril; Sweeney, Colm; Danis, François; Hertzog, Albert; Engel, Andreas; Bönisch, Harald; Picon, Laurence

    2017-06-01

    An original and innovative sampling system called AirCore was presented by NOAA in 2010 Karion et al.(2010). It consists of a long ( > 100 m) and narrow ( < 1 cm) stainless steel tube that can retain a profile of atmospheric air. The captured air sample has then to be analyzed with a gas analyzer for trace mole fraction. In this study, we introduce a new AirCore aiming to improve resolution along the vertical with the objectives to (i) better capture the vertical distribution of CO2 and CH4, (ii) provide a tool to compare AirCores and validate the estimated vertical resolution achieved by AirCores. This (high-resolution) AirCore-HR consists of a 300 m tube, combining 200 m of 0.125 in. (3.175 mm) tube and a 100 m of 0.25 in. (6.35 mm) tube. This new configuration allows us to achieve a vertical resolution of 300 m up to 15 km and better than 500 m up to 22 km (if analysis of the retained sample is performed within 3 h). The AirCore-HR was flown for the first time during the annual StratoScience campaign from CNES in August 2014 from Timmins (Ontario, Canada). High-resolution vertical profiles of CO2 and CH4 up to 25 km were successfully retrieved. These profiles revealed well-defined transport structures in the troposphere (also seen in CAMS-ECMWF high-resolution forecasts of CO2 and CH4 profiles) and captured the decrease of CO2 and CH4 in the stratosphere. The multi-instrument gondola also carried two other low-resolution AirCore-GUF that allowed us to perform direct comparisons and study the underlying processing method used to convert the sample of air to greenhouse gases vertical profiles. In particular, degrading the AirCore-HR derived profiles to the low resolution of AirCore-GUF yields an excellent match between both sets of CH4 profiles and shows a good consistency in terms of vertical structures. This fully validates the theoretical vertical resolution achievable by AirCores. Concerning CO2 although a good agreement is found in terms of vertical structure

  3. Contemporary-use pesticides in personal air samples during pregnancy and blood samples at delivery among urban minority mothers and newborns.

    PubMed Central

    Whyatt, Robin M; Barr, Dana B; Camann, David E; Kinney, Patrick L; Barr, John R; Andrews, Howard F; Hoepner, Lori A; Garfinkel, Robin; Hazi, Yair; Reyes, Andria; Ramirez, Judyth; Cosme, Yesenia; Perera, Frederica P

    2003-01-01

    We have measured 29 pesticides in plasma samples collected at birth between 1998 and 2001 from 230 mother and newborn pairs enrolled in the Columbia Center for Children's Environmental Health prospective cohort study. Our prior research has shown widespread pesticide use during pregnancy among this urban minority cohort from New York City. We also measured eight pesticides in 48-hr personal air samples collected from the mothers during pregnancy. The following seven pesticides were detected in 48-83% of plasma samples (range, 1-270 pg/g): the organophosphates chlorpyrifos and diazinon, the carbamates bendiocarb and 2-isopropoxyphenol (metabolite of propoxur), and the fungicides dicloran, phthalimide (metabolite of folpet and captan), and tetrahydrophthalimide (metabolite of captan and captafol). Maternal and cord plasma levels were similar and, except for phthalimide, were highly correlated (p < 0.001). Chlorpyrifos, diazinon, and propoxur were detected in 100% of personal air samples (range, 0.7-6,010 ng/m(3)). Diazinon and propoxur levels were significantly higher in the personal air of women reporting use of an exterminator, can sprays, and/or pest bombs during pregnancy compared with women reporting no pesticide use or use of lower toxicity methods only. A significant correlation was seen between personal air level of chlorpyrifos, diazinon, and propoxur and levels of these insecticides or their metabolites in plasma samples (maternal and/or cord, p < 0.05). The fungicide ortho-phenylphenol was also detected in 100% of air samples but was not measured in plasma. The remaining 22 pesticides were detected in 0-45% of air or plasma samples. Chlorpyrifos, diazinon, propoxur, and bendiocarb levels in air and/or plasma decreased significantly between 1998 and 2001. Findings indicate that pesticide exposures are frequent but decreasing and that the pesticides are readily transferred to the developing fetus during pregnancy. PMID:12727605

  4. Profiling quinones in ambient air samples collected from the Athabasca region (Canada).

    PubMed

    Wnorowski, Andrzej; Charland, Jean-Pierre

    2017-12-01

    This paper presents new findings on polycyclic aromatic hydrocarbon oxidation products-quinones that were collected in ambient air samples in the proximity of oil sands exploration. Quinones were characterized for their diurnal concentration variability, phase partitioning, and molecular size distribution. Gas-phase (GP) and particle-phase (PM) ambient air samples were collected separately in the summer; a lower quinone content was observed in the PM samples from continuous 24-h sampling than from combined 12-h sampling (day and night). The daytime/nocturnal samples demonstrated that nighttime conditions led to lower concentrations and some quinones not being detected. The highest quinone levels were associated with wind directions originating from oil sands exploration sites. The statistical correlation with primary pollutants directly emitted from oil sands industrial activities indicated that the bulk of the detected quinones did not originate directly from primary emission sources and that quinone formation paralleled a reduction in primary source NO x levels. This suggests a secondary chemical transformation of primary pollutants as the origin of the determined quinones. Measurements of 19 quinones included five that have not previously been reported in ambient air or in Standard Reference Material 1649a/1649b and seven that have not been previously measured in ambient air in the underivatized form. This is the first paper to report on quinone characterization in secondary organic aerosols originating from oil sands activities, to distinguish chrysenequinone and anthraquinone positional isomers in ambient air, and to report the requirement of daylight conditions for benzo[a]pyrenequinone and naphthacenequinone to be present in ambient air. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  5. Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study.

    PubMed

    Montagna, Maria Teresa; De Giglio, Osvalda; Cristina, Maria Luisa; Napoli, Christian; Pacifico, Claudia; Agodi, Antonella; Baldovin, Tatjana; Casini, Beatrice; Coniglio, Maria Anna; D'Errico, Marcello Mario; Delia, Santi Antonino; Deriu, Maria Grazia; Guida, Marco; Laganà, Pasqualina; Liguori, Giorgio; Moro, Matteo; Mura, Ida; Pennino, Francesca; Privitera, Gaetano; Romano Spica, Vincenzo; Sembeni, Silvia; Spagnolo, Anna Maria; Tardivo, Stefano; Torre, Ida; Valeriani, Federica; Albertini, Roberto; Pasquarella, Cesira

    2017-06-22

    Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and Coriolis ® μ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the Coriolis ® μ were also analyzed by real-time PCR. Legionella presence in the air and water was then compared by sequence-based typing (SBT) methods. Air contamination was found in four HF (36.4%) by at least one of the culturable methods. The culturable investigation by Coriolis ® μ did not yield Legionella in any enrolled HF. However, molecular investigation using Coriolis ® μ resulted in eight HF testing positive for Legionella in the air. Comparison of Legionella air and water contamination indicated that Legionella water concentration could be predictive of its presence in the air. Furthermore, a molecular study of 12 L. pneumophila strains confirmed a match between the Legionella strains from air and water samples by SBT for three out of four HF that tested positive for Legionella by at least one of the culturable methods. Overall, our study shows that Legionella air detection cannot replace water sampling because the absence of microorganisms from the air does not necessarily represent their absence from water; nevertheless, air sampling may provide useful information for risk assessment. The liquid impingement technique appears to have the greatest capacity for collecting airborne Legionella if combined with molecular investigations.

  6. Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study

    PubMed Central

    Montagna, Maria Teresa; De Giglio, Osvalda; Cristina, Maria Luisa; Napoli, Christian; Pacifico, Claudia; Agodi, Antonella; Baldovin, Tatjana; Casini, Beatrice; Coniglio, Maria Anna; D’Errico, Marcello Mario; Delia, Santi Antonino; Deriu, Maria Grazia; Guida, Marco; Laganà, Pasqualina; Liguori, Giorgio; Moro, Matteo; Mura, Ida; Pennino, Francesca; Privitera, Gaetano; Romano Spica, Vincenzo; Sembeni, Silvia; Spagnolo, Anna Maria; Tardivo, Stefano; Torre, Ida; Valeriani, Federica; Albertini, Roberto; Pasquarella, Cesira

    2017-01-01

    Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and Coriolis®μ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the Coriolis®μ were also analyzed by real-time PCR. Legionella presence in the air and water was then compared by sequence-based typing (SBT) methods. Air contamination was found in four HF (36.4%) by at least one of the culturable methods. The culturable investigation by Coriolis®μ did not yield Legionella in any enrolled HF. However, molecular investigation using Coriolis®μ resulted in eight HF testing positive for Legionella in the air. Comparison of Legionella air and water contamination indicated that Legionella water concentration could be predictive of its presence in the air. Furthermore, a molecular study of 12 L. pneumophila strains confirmed a match between the Legionella strains from air and water samples by SBT for three out of four HF that tested positive for Legionella by at least one of the culturable methods. Overall, our study shows that Legionella air detection cannot replace water sampling because the absence of microorganisms from the air does not necessarily represent their absence from water; nevertheless, air sampling may provide useful information for risk assessment. The liquid impingement technique appears to have the greatest capacity for collecting airborne Legionella if combined with molecular investigations. PMID:28640202

  7. Composition Alteration of Stratospheric Air Due to Sampling through a Flow Tube.

    DTIC Science & Technology

    1984-02-03

    C. C. , Forsberg, C. A. , and Pieri , H. V. (19)83) Stratospheric N 20 CF2 Cl and CFCI3 composition studies utilizing in situ cryogenic whole air...Gas-Surface Interactions in Cryogenic Whole Air Sampling, AFGL-TR-81-0162, AD A108255. 19. Gallagher, C. C., Forsberg, C. A., and Pieri , R. V. (1983...Gallagher, C. C., Forsberg, C. A., Pieri , R. V., and Faucher, G. A. (1983a) Oxides of Nitrogen Content of Whole Air Samples Obtained at Altitudes From 12

  8. Carter Carburetor Weekly Air Monitoring & Sampling Report - March 7, 2013 - March 13, 2016

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  9. Novel sample preparation technique with needle-type micro-extraction device for volatile organic compounds in indoor air samples.

    PubMed

    Ueta, Ikuo; Mizuguchi, Ayako; Fujimura, Koji; Kawakubo, Susumu; Saito, Yoshihiro

    2012-10-09

    A novel needle-type sample preparation device was developed for the effective preconcentration of volatile organic compounds (VOCs) in indoor air before gas chromatography-mass spectrometry (GC-MS) analysis. To develop a device for extracting a wide range of VOCs typically found in indoor air, several types of particulate sorbents were tested as the extraction medium in the needle-type extraction device. To determine the content of these VOCs, air samples were collected for 30min with the packed sorbent(s) in the extraction needle, and the extracted VOCs were thermally desorbed in a GC injection port by the direct insertion of the needle. A double-bed sorbent consisting of a needle packed with divinylbenzene and activated carbon particles exhibited excellent extraction and desorption performance and adequate extraction capacity for all the investigated VOCs. The results also clearly demonstrated that the proposed sample preparation method is a more rapid, simpler extraction/desorption technique than traditional sample preparation methods. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Can Particulate Air Sampling Predict Microbial Load in Operating Theatres for Arthroplasty?

    PubMed Central

    Cristina, Maria Luisa; Spagnolo, Anna Maria; Sartini, Marina; Panatto, Donatella; Gasparini, Roberto; Orlando, Paolo; Ottria, Gianluca; Perdelli, Fernanda

    2012-01-01

    Several studies have proposed that the microbiological quality of the air in operating theatres be indirectly evaluated by means of particle counting, a technique derived from industrial clean-room technology standards, using airborne particle concentration as an index of microbial contamination. However, the relationship between particle counting and microbiological sampling has rarely been evaluated and demonstrated in operating theatres. The aim of the present study was to determine whether particle counting could predict microbiological contamination of the air in an operating theatre during 95 surgical arthroplasty procedures. This investigation was carried out over a period of three months in 2010 in an orthopedic operating theatre devoted exclusively to prosthetic surgery. During each procedure, the bacterial contamination of the air was determined by means of active sampling; at the same time, airborne particulate contamination was assessed throughout the entire procedure. On considering the total number of surgical operations, the mean value of the total bacterial load in the center of the operating theatre proved to be 35 CFU/m3; the mean particle count was 4,194,569 no./m3 for particles of diameter ≥0.5 µm and 13,519 no./m3 for particles of diameter ≥5 µm. No significant differences emerged between the median values of the airborne microbial load recorded during the two types of procedure monitored. Particulates with a diameter of ≥0.5 µm were detected in statistically higher concentrations (p<0.001) during knee-replacement procedures. By contrast, particulates with a diameter of ≥5 µm displayed a statistically higher concentration during hip-replacement procedures (p<0.05). The results did not reveal any statistically significant correlation between microbial loads and particle counts for either of the particle diameters considered (≥0.5 µm and ≥5 µm). Consequently, microbiological monitoring remains the most suitable method of

  11. Can particulate air sampling predict microbial load in operating theatres for arthroplasty?

    PubMed

    Cristina, Maria Luisa; Spagnolo, Anna Maria; Sartini, Marina; Panatto, Donatella; Gasparini, Roberto; Orlando, Paolo; Ottria, Gianluca; Perdelli, Fernanda

    2012-01-01

    Several studies have proposed that the microbiological quality of the air in operating theatres be indirectly evaluated by means of particle counting, a technique derived from industrial clean-room technology standards, using airborne particle concentration as an index of microbial contamination. However, the relationship between particle counting and microbiological sampling has rarely been evaluated and demonstrated in operating theatres. The aim of the present study was to determine whether particle counting could predict microbiological contamination of the air in an operating theatre during 95 surgical arthroplasty procedures. This investigation was carried out over a period of three months in 2010 in an orthopedic operating theatre devoted exclusively to prosthetic surgery. During each procedure, the bacterial contamination of the air was determined by means of active sampling; at the same time, airborne particulate contamination was assessed throughout the entire procedure. On considering the total number of surgical operations, the mean value of the total bacterial load in the center of the operating theatre proved to be 35 CFU/m(3); the mean particle count was 4,194,569 no./m(3) for particles of diameter ≥0.5 µm and 13,519 no./m(3) for particles of diameter ≥5 µm. No significant differences emerged between the median values of the airborne microbial load recorded during the two types of procedure monitored. Particulates with a diameter of ≥0.5 µm were detected in statistically higher concentrations (p<0.001) during knee-replacement procedures. By contrast, particulates with a diameter of ≥5 µm displayed a statistically higher concentration during hip-replacement procedures (p<0.05). The results did not reveal any statistically significant correlation between microbial loads and particle counts for either of the particle diameters considered (≥0.5 µm and ≥5 µm). Consequently, microbiological monitoring remains the most suitable method of

  12. Sampling for Air Chemical Emissions from the Life Sciences Laboratory II

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ballinger, Marcel Y.; Lindberg, Michael J.

    Sampling for air chemical emissions from the Life Science Laboratory II (LSL-II) ventilation stack was performed in an effort to determine potential exposure of maintenance staff to laboratory exhaust on the building roof. The concern about worker exposure was raised in December 2015 and several activities were performed to assist in estimating exposure concentrations. Data quality objectives were developed to determine the need for and scope and parameters of a sampling campaign to measure chemical emissions from research and development activities to the outside air. The activities provided data on temporal variation of air chemical concentrations and a basis formore » evaluating calculated emissions. Sampling for air chemical emissions was performed in the LSL-II ventilation stack over the 6-week period from July 26 to September 1, 2016. A total of 12 sampling events were carried out using 16 sample media. Resulting analysis provided concentration data on 49 analytes. All results were below occupational exposure limits and most results were below detection limits. When compared to calculated emissions, only 5 of the 49 chemicals had measured concentrations greater than predicted. This sampling effort will inform other study components to develop a more complete picture of a worker’s potential exposure from LSL-II rooftop activities. Mixing studies were conducted to inform spatial variation in concentrations at other rooftop locations and can be used in conjunction with these results to provide temporal variations in concentrations for estimating the potential exposure to workers working in and around the LSL-II stack.« less

  13. Evaluation of Urban Air Quality By Passive Sampling Technique

    NASA Astrophysics Data System (ADS)

    Nunes, T. V.; Miranda, A. I.; Duarte, S.; Lima, M. J.

    Aveiro is a flat small city in the centre of Portugal, close to the Atlantic coast. In the last two decades an intensive development of demographic, traffic and industry growth in the region was observed which was reflected on the air quality degrada- tion. In order to evaluate the urban air quality in Aveiro, a field-monitoring network by passive sampling with high space resolution was implemented. Twenty-four field places were distributed in a area of 3x3 Km2 and ozone and NO2 concentrations were measured. The site distribution density was higher in the centre, 250x250 m2 than in periphery where a 500x500 m2 grid was used. The selection of field places took into consideration the choice criteria recommendation by United Kingdom environmental authorities, and three tubes and a blank tube for each pollutant were used at each site. The sampling system was mounted at 3m from the ground usually profiting the street lampposts. Concerning NO2 acrylic tubes were used with 85 mm of length and an in- ternal diameter of 12mm, where in one of the extremities three steel grids impregnated with a solution of TEA were placed and fixed with a polyethylene end cup (Heal et al., 1999); PFA Teflon tube with 53 mm of length and 9 mm of internal diameter and three impregnated glass filters impregnated with DPE solution fixed by a teflon end cup was used for ozone sampling (Monn and Hargartner, 1990). The passive sampling method for ozone and nitrogen dioxide was compared with continuous measurements, but the amount of measurements wasnSt enough for an accurate calibration and validation of the method. Although this constraint the field observations (June to August 2001) for these two pollutants assign interesting information about the air quality in the urban area. A krigger method of interpolation (Surfer- Golden Software-2000) was applied to field data to obtain isolines distribution of NO2 and ozone concentration for the studied area. Even the used passive sampling method has many

  14. Calibration of polyurethane foam (PUF) disk passive air samplers for quantitative measurement of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs): factors influencing sampling rates.

    PubMed

    Hazrati, Sadegh; Harrad, Stuart

    2007-03-01

    PUF disk passive air samplers are increasingly employed for monitoring of POPs in ambient air. In order to utilize them as quantitative sampling devices, a calibration experiment was conducted. Time integrated indoor air concentrations of PCBs and PBDEs were obtained from a low volume air sampler operated over a 50 d period alongside the PUF disk samplers in the same office microenvironment. Passive sampling rates for the fully-sheltered sampler design employed in our research were determined for the 51 PCB and 7 PBDE congeners detected in all calibration samples. These values varied from 0.57 to 1.55 m3 d(-1) for individual PCBs and from 1.1 to 1.9 m3 d(-1) for PBDEs. These values are appreciably lower than those reported elsewhere for different PUF disk sampler designs (e.g. partially sheltered) employed under different conditions (e.g. in outdoor air), and derived using different calibration experiment configurations. This suggests that sampling rates derived for a specific sampler configuration deployed under specific environmental conditions, should not be extrapolated to different sampler configurations. Furthermore, our observation of variable congener-specific sampling rates (consistent with other studies), implies that more research is required in order to understand fully the factors that influence sampling rates. Analysis of wipe samples taken from the inside of the sampler housing, revealed evidence that the housing surface scavenges particle bound PBDEs.

  15. Solubility testing of actinides on breathing-zone and area air samples

    NASA Astrophysics Data System (ADS)

    Metzger, Robert Lawrence

    The solubility of inhaled radionuclides in the human lung is an important characteristic of the compounds needed to perform internal dosimetry assessments for exposed workers. A solubility testing method for uranium and several common actinides has been developed with sufficient sensitivity to allow profiles to be determined from routine breathing zone and area air samples in the workplace. Air samples are covered with a clean filter to form a filter-sample-filter sandwich which is immersed in an extracellular lung serum simulant solution. The sample is moved to a fresh beaker of the lung fluid simulant each day for one week, and then weekly until the end of the 28 day test period. The soak solutions are wet ashed with nitric acid and hydrogen peroxide to destroy the organic components of the lung simulant solution prior to extraction of the nuclides of interest directly into an extractive scintillator for subsequent counting on a Photon-Electron Rejecting Alpha Liquid Scintillation (PERALSsp°ler ) spectrometer. Solvent extraction methods utilizing the extractive scintillators have been developed for the isotopes of uranium, plutonium, and curium. The procedures normally produce an isotopic recovery greater than 95% and have been used to develop solubility profiles from air samples with 40 pCi or less of Usb3Osb8. This makes it possible to characterize solubility profiles in every section of operating facilities where airborne nuclides are found using common breathing zone air samples. The new method was evaluated by analyzing uranium compounds from two uranium mills whose product had been previously analyzed by in vitro solubility testing in the laboratory and in vivo solubility testing in rodents. The new technique compared well with the in vivo rodent solubility profiles. The method was then used to evaluate the solubility profiles in all process sections of an operating in situ uranium plant using breathing zone and area air samples collected during routine

  16. High-throughput liquid-absorption air-sampling apparatus and methods

    DOEpatents

    Zaromb, Solomon

    2000-01-01

    A portable high-throughput liquid-absorption air sampler [PHTLAAS] has an asymmetric air inlet through which air is drawn upward by a small and light-weight centrifugal fan driven by a direct current motor that can be powered by a battery. The air inlet is so configured as to impart both rotational and downward components of motion to the sampled air near said inlet. The PHTLAAS comprises a glass tube of relatively small size through which air passes at a high rate in a swirling, highly turbulent motion, which facilitates rapid transfer of vapors and particulates to a liquid film covering the inner walls of the tube. The pressure drop through the glass tube is <10 cm of water, usually <5 cm of water. The sampler's collection efficiency is usually >20% for vapors or airborne particulates in the 2-3.mu. range and >50% for particles larger than 4.mu.. In conjunction with various analyzers, the PHTLAAS can serve to monitor a variety of hazardous or illicit airborne substances, such as lead-containing particulates, tritiated water vapor, biological aerosols, or traces of concealed drugs or explosives.

  17. Carter Carburetor Weekly Air Monitoring & Sampling Report - November 30, 2015 – December 6, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  18. Carter Carburetor Weekly Air Monitoring & Sampling Report - October 26, 2015 – November 1, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  19. Carter Carburetor Weekly Air Monitoring & Sampling Report - February 15, 2016 – February 21, 2016

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  20. Carter Carburetor Weekly Air Monitoring & Sampling Report - October 12, 2015 – October 18, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  1. Carter Carburetor Weekly Air Monitoring & Sampling Report - November 23, 2015 – November 29, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  2. Carter Carburetor Weekly Air Monitoring & Sampling Report - October 5, 2015 – October 11, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  3. Carter Carburetor Weekly Air Monitoring & Sampling Report - February 1, 2016 – February 7, 2016

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  4. Carter Carburetor Weekly Air Monitoring & Sampling Report - September 28, 2015 – October 4, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  5. Carter Carburetor Weekly Air Monitoring & Sampling Report - November 16, 2015 – November 22, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  6. Carter Carburetor Weekly Air Monitoring & Sampling Report - November 9, 2015 – November 15, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  7. Carter Carburetor Weekly Air Monitoring & Sampling Report - October 19, 2015 – October 25, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  8. Carter Carburetor Weekly Air Monitoring & Sampling Report - November 2, 2015 – November 8, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  9. On the construction, comparison, and variability of airsheds for interpreting semivolatile organic compounds in passively sampled air.

    PubMed

    Westgate, John N; Wania, Frank

    2011-10-15

    Air mass origin as determined by back trajectories often aids in explaining some of the short-term variability in the atmospheric concentrations of semivolatile organic contaminants. Airsheds, constructed by amalgamating large numbers of back trajectories, capture average air mass origins over longer time periods and thus have found use in interpreting air concentrations obtained by passive air samplers. To explore some of their key characteristics, airsheds for 54 locations on Earth were constructed and compared for roundness, seasonality, and interannual variability. To avoid the so-called "pole problem" and to simplify the calculation of roundness, a "geodesic grid" was used to bin the back-trajectory end points. Departures from roundness were seen to occur at all latitudes and to correlate significantly with local slope but no strong relationship between latitude and roundness was revealed. Seasonality and interannual variability vary widely enough to imply that static models of transport are not sufficient to describe the proximity of an area to potential sources of contaminants. For interpreting an air measurement an airshed should be generated specifically for the deployment time of the sampler, especially when investigating long-term trends. Samples taken in a single season may not represent the average annual atmosphere, and samples taken in linear, as opposed to round, airsheds may not represent the average atmosphere in the area. Simple methods are proposed to ascertain the significance of an airshed or individual cell. It is recommended that when establishing potential contaminant source regions only end points with departure heights of less than ∼700 m be considered.

  10. Air Sampling Logbook of Region 4 Yellow Bluff Air Study Wilcox County, Alabama SESD Project Identification Number:11-0068

    EPA Pesticide Factsheets

    Contains the Air Sampling Logbook between 1-24-2011 thru 1-28-2011 from the Region 4 Yellow Bluff Air Study Wilcox County, Alabama SESD Project Identification Number:11-0068 November 2010-December 2010

  11. Chemical reactivities of ambient air samples in three Southern California communities

    PubMed Central

    Eiguren-Fernandez, Arantza; Di Stefano, Emma; Schmitz, Debra A.; Guarieiro, Aline Lefol Nani; Salinas, Erika M.; Nasser, Elina; Froines, John R.; Cho, Arthur K.

    2015-01-01

    The potential adverse health effects of PM2.5 and vapor samples from three communities that neighbor railyards, Commerce (CM), Long Beach (LB), and San Bernardino (SB), were assessed by determination of chemical reactivities attributed to the induction of oxidative stress by air pollutants. The assays used were dithiothreitol (DTT) and dihydrobenzoic acid (DHBA) based procedures for prooxidant content and a glyceraldehyde-3-phosphate dehydrogenase (GAPDH) assay for electrophiles. Prooxidants and electrophiles have been proposed as the reactive chemical species responsible for the induction of oxidative stress by air pollution mixtures. The PM2.5 samples from CM and LB sites showed seasonal differences in reactivities with higher levels in the winter whereas the SB sample differences were reversed. The reactivities in the vapor samples were all very similar, except for the summer SB samples, which contained higher levels of both prooxidants and electrophiles. The results suggest the observed reactivities reflect general geographical differences rather than direct effects of the railyards. Distributional differences in reactivities were also observed with PM2.5 fractions containing most of the prooxidants (74–81%) and the vapor phase most of the electrophiles (82–96%). The high levels of the vapor phase electrophiles and their potential for adverse biological effects point out the importance of the vapor phase in assessing the potential health effects of ambient air. PMID:25947123

  12. Atmospheric Methane Mixing Ratios--The NOAA/CMDL Global Cooperative Air Sampling Network\\, 1983-1993

    DOE Data Explorer

    Dlugokencky, E. J. [National Oceanic and Atmospheric Administration, Boulder, Colorado (USA); Lang, P. M. [National Oceanic and Atmospheric Administration, Boulder, Colorado (USA); Masarie, K. A. [National Oceanic and Atmospheric Administration, Boulder, Colorado (USA); Steele, L. P. [Commonwealth Scientific and Industrial Research Organisation, Aspendale, Victoria, Australia

    1994-01-01

    This data base presents atmospheric methane (CH4) mixing ratios from flask air samples collected over the period 1983-1993 by the National Oceanic and Atmospheric Administration, Climate Monitoring and Diagnostics Laboratory's (NOAA/CMDL's) global cooperative air sampling network. Air samples were collected approximately once per week at 44 fixed sites (37 of which were still active at the end of 1993). Samples were also collected at 5 degree latitude intervals along shipboard cruise tracks in the Pacific Ocean between North America and New Zealand (or Australia) and at 3 degree latitude intervals along cruise tracks in the South China Sea between Singapore and Hong Kong. The shipboard measurements were made approximately every 3 weeks per latitude zone by each of two ships in the Pacific Ocean and approximately once every week per latitude zone in the South China Sea. All samples were analyzed for CH4 at the NOAA/CMDL laboratory in Boulder, Colorado, by gas chromatography with flame ionization detection, and each aliquot was referenced to the NOAA/CMDL methane standard scale. In addition to providing the complete set of atmospheric CH4 measurements from flask air samples collected at the NOAA/CMDL network sites, this data base also includes files which list monthly mean mixing ratios derived from the individual flask air measurements. These monthly summary data are available for 35 of the fixed sites and 21 of the shipboard sampling sites.

  13. Curve fitting air sample filter decay curves to estimate transuranic content.

    PubMed

    Hayes, Robert B; Chiou, Hung Cheng

    2004-01-01

    By testing industry standard techniques for radon progeny evaluation on air sample filters, a new technique is developed to evaluate transuranic activity on air filters by curve fitting the decay curves. The industry method modified here is simply the use of filter activity measurements at different times to estimate the air concentrations of radon progeny. The primary modification was to not look for specific radon progeny values but rather transuranic activity. By using a method that will provide reasonably conservative estimates of the transuranic activity present on a filter, some credit for the decay curve shape can then be taken. By carrying out rigorous statistical analysis of the curve fits to over 65 samples having no transuranic activity taken over a 10-mo period, an optimization of the fitting function and quality tests for this purpose was attained.

  14. Air-sampling inlet contamination by aircraft emissions on the NASA CV-990 aircraft

    NASA Technical Reports Server (NTRS)

    Condon, E. P.; Vedder, J. F.

    1984-01-01

    Results of an experimental investigation of the contamination of air sampling inlets by aircraft emissions from the NASA CV-990 research aircraft are presented. This four-engine jet aircraft is a NASA facility used for many different atmospheric and meteorological experiments, as well as for developing spacecraft instrumentation for remote measurements. Our investigations were performed to provide information on which to base the selection of sampling locations for a series of multi-instrument missions for measuring tropospheric trace gases. The major source of contamination is the exhaust from the jet engines, which generate many of the same gases that are of interest in atmospheric chemistry, as well as other gases that may interfere with sampling measurements. The engine exhaust contains these gases in mixing ratios many orders of magnitude greater than those that occur in the clean atmosphere which the missions seek to quantify. Pressurized samples of air were collected simultaneously from a scoop located forward of the engines to represent clean air and from other multiport scoops at various aft positions on the aircraft. The air samples were analyzed in the laboratory by gas chromatography for carbon monoxide, an abundant combustion by-product. Data are presented for various scoop locations under various flight conditions.

  15. A new technique for preliminary estimates of TRU activity on air sample filters and radiological smears.

    PubMed

    Hayes, Robert

    2004-10-01

    In most nuclear facilities, fixed air samplers and sometimes portable air samplers are used where some probability of a release exists but is not expected, and so the added expense and effort of using a continuous air monitor is not deemed justified. When a release is suspected, naturally occurring radioactive material buildup on the filter typically prevents any quantitative measurements within the first day or so. Likewise, outdoor air measurements suffer from the same limitations (such as those taken during the Los Alamos fires) and so any rapid quantifiable measurements of fixed air sampler/portable air sampler filters which are technically defendable (even though conservative) are of use. The technique presented here is only intended for use in routine health physics survey applications and does not presently appear to be appropriate for sub pico Curie activity determinations. This study evaluates the utility of using a portable continuous air monitor as an alpha spectrometer to make transuranic activity determinations of samples using both the built in algorithm for air monitoring and a simple region of interest analysis. All samples evaluated were from air sample filters taken using a portable air sampler. Samples were taken over many months to quantify effects from natural variation in radon progeny activity distributions.

  16. Evaluation of membrane filter field monitors for microbiological air sampling

    NASA Technical Reports Server (NTRS)

    Fields, N. D.; Oxborrow, G. S.; Puleo, J. R.; Herring, C. M.

    1974-01-01

    Due to area constraints encountered in assembly and testing areas of spacecraft, the membrane filter field monitor (MF) and the National Aeronautics and Space Administration-accepted Reyniers slit air sampler were compared for recovery of airborne microbial contamination. The intramural air in a microbiological laboratory area and a clean room environment used for the assembly and testing of the Apollo spacecraft was studied. A significantly higher number of microorganisms was recovered by the Reyniers sampler. A high degree of consistency between the two sampling methods was shown by a regression analysis, with a correlation coefficient of 0.93. The MF samplers detected 79% of the concentration measured by the Reyniers slit samplers. The types of microorganisms identified from both sampling methods were similar.

  17. The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

    PubMed

    Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

    2011-09-01

    Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration.

  18. Comparison of indoor air sampling and dust collection methods for fungal exposure assessment using quantitative PCR.

    PubMed

    Cox, Jennie; Indugula, Reshmi; Vesper, Stephen; Zhu, Zheng; Jandarov, Roman; Reponen, Tiina

    2017-10-18

    Evaluating fungal contamination indoors is complicated because of the many different sampling methods utilized. In this study, fungal contamination was evaluated using five sampling methods and four matrices for results. The five sampling methods were a 48 hour indoor air sample collected with a Button™ inhalable aerosol sampler and four types of dust samples: a vacuumed floor dust sample, newly settled dust collected for four weeks onto two types of electrostatic dust cloths (EDCs) in trays, and a wipe sample of dust from above floor surfaces. The samples were obtained in the bedrooms of asthmatic children (n = 14). Quantitative polymerase chain reaction (qPCR) was used to analyze the dust and air samples for the 36 fungal species that make up the Environmental Relative Moldiness Index (ERMI). The results from the samples were compared by four matrices: total concentration of fungal cells, concentration of fungal species associated with indoor environments, concentration of fungal species associated with outdoor environments, and ERMI values (or ERMI-like values for air samples). The ERMI values for the dust samples and the ERMI-like values for the 48 hour air samples were not significantly different. The total cell concentrations of the 36 species obtained with the four dust collection methods correlated significantly (r = 0.64-0.79, p < 0.05), with the exception of the vacuumed floor dust and newly settled dust. In addition, fungal cell concentrations of indoor associated species correlated well between all four dust sampling methods (r = 0.68-0.86, p < 0.01). No correlation was found between the fungal concentrations in the air and dust samples primarily because of differences in concentrations of Cladosporium cladosporioides Type 1 and Epicoccum nigrum. A representative type of dust sample and a 48 hour air sample might both provide useful information about fungal exposures.

  19. Applicability of canisters for sample storage in the determination of hazardous air pollutants

    NASA Astrophysics Data System (ADS)

    Kelly, Thomas J.; Holdren, Michael W.

    This paper evaluates the applicability of canisters for storage of air samples containing volatile organic compounds listed among the 189 hazardous air pollutants (HAPs) in the 1990 U.S. Clean Air Act Amendments. Nearly 100 HAPs have sufficient vapor pressure to be considered volatile compounds. Of those volatile organic HAPs, 52 have been tested previously for stability during storage in canisters. The published HAP stability studies are reviewed, illustrating that for most of the 52 HAPs tested, canisters are an effective sample storage approach. However, the published stability studies used a variety of canister types and test procedures, and generally considered only a few compounds in a very small set of canisters. A comparison of chemical and physical properties of the HAPs has also been conducted, to evaluate the applicability of canister sampling for other HAPs, for which canister stability testing has never been conducted. Of 45 volatile HAPs never tested in canisters, this comparison identifies nine for which canisters should be effective, and 17 for which canisters are not likely to be effective. For the other 19 HAPs, no clear decision can be reached on the likely applicability of air sample storage in canisters.

  20. Volatile organic compounds: sampling methods and their worldwide profile in ambient air.

    PubMed

    Kumar, Anuj; Víden, Ivan

    2007-08-01

    The atmosphere is a particularly difficult analytical system because of the very low levels of substances to be analysed, sharp variations in pollutant levels with time and location, differences in wind, temperature and humidity. This makes the selection of an efficient sampling technique for air analysis a key step to reliable results. Generally, methods for volatile organic compounds sampling include collection of the whole air or preconcentration of samples on adsorbents. All the methods vary from each other according to the sampling technique, type of sorbent, method of extraction and identification technique. In this review paper we discuss various important aspects for sampling of volatile organic compounds by the widely used and advanced sampling methods. Characteristics of various adsorbents used for VOCs sampling are also described. Furthermore, this paper makes an effort to comprehensively review the concentration levels of volatile organic compounds along with the methodology used for analysis, in major cities of the world.

  1. Polyurethane foam (PUF) disks passive air samplers: wind effect on sampling rates.

    PubMed

    Tuduri, Ludovic; Harner, Tom; Hung, Hayley

    2006-11-01

    Different passive sampler housings were evaluated for their wind dampening ability and how this might translate to variability in sampler uptake rates. Polyurethane foam (PUF) disk samplers were used as the sampling medium and were exposed to a PCB-contaminated atmosphere in a wind tunnel. The effect of outside wind speed on PUF disk sampling rates was evaluated by exposing polyurethane foam (PUF) disks to a PCB-contaminated air stream in a wind tunnel over air velocities in the range 0 to 1.75 m s-1. PUF disk sampling rates increased gradually over the range 0-0.9 m s-1 at approximately 4.5-14.6 m3 d-1 and then increased sharply to approximately 42 m3 d-1 at approximately 1.75 m s-1 (sum of PCBs). The results indicate that for most field deployments the conventional 'flying saucer' housing adequately dampens the wind effect and will yield approximately time-weighted air concentrations.

  2. Permeability of gypsum samples dehydrated in air

    NASA Astrophysics Data System (ADS)

    Milsch, Harald; Priegnitz, Mike; Blöcher, Guido

    2011-09-01

    We report on changes in rock permeability induced by devolatilization reactions using gypsum as a reference analog material. Cylindrical samples of natural alabaster were dehydrated in air (dry) for up to 800 h at ambient pressure and temperatures between 378 and 423 K. Subsequently, the reaction kinetics, so induced changes in porosity, and the concurrent evolution of sample permeability were constrained. Weighing the heated samples in predefined time intervals yielded the reaction progress where the stoichiometric mass balance indicated an ultimate and complete dehydration to anhydrite regardless of temperature. Porosity showed to continuously increase with reaction progress from approximately 2% to 30%, whilst the initial bulk volume remained unchanged. Within these limits permeability significantly increased with porosity by almost three orders of magnitude from approximately 7 × 10-19 m2 to 3 × 10-16 m2. We show that - when mechanical and hydraulic feedbacks can be excluded - permeability, reaction progress, and porosity are related unequivocally.

  3. An Autosampler and Field Sample Carrier for Maximizing Throughput Using an Open-Air, Surface Sampling Ion Source for MS

    EPA Science Inventory

    A recently developed, commercially available, open-air, surface sampling ion source for mass spectrometers provides individual analyses in several seconds. To realize its full throughput potential, an autosampler and field sample carrier were designed and built. The autosampler ...

  4. Determination of methyl bromide in air samples by headspace gas chromatography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Woodrow, J.E.; McChesney, M.M.; Seiber, J.N.

    1988-03-01

    Methyl bromide is extensively used in agriculture (4 x 10/sup 6/ kg for 1985 in California alone as a fumigant to control nematodes, weeds, and fungi in soil and insect pests in harvested grains and nuts. Given its low boiling point (3.8/sup 0/C) and high vapor pressure (approx. 1400 Torr at 20/sup 0/C), methyl bromide will readily diffuse if not rigorously contained. Methods for determining methyl bromide and other halocarbons in air vary widely. A common practice is to trap the material from air on an adsorbent, such as polymeric resins, followed by thermal desorption either directly into the analyticalmore » instrumentation or after intermediary cryofocusing. While in some cases analytical detection limits were reasonable (parts per million range), many of the published methods were labor intensive and required special handling techniques that precluded high sample throughput. They describe here a method for the sampling and analysis of airborne methyl bromide that was designed to handle large numbers of samples through automating some critical steps of the analysis. The result was a method that allowed around-the-clock operation with a minimum of operator attention. Furthermore, the method was not specific to methyl bromide and could be used to determine other halocarbons in air.« less

  5. Comparison of mold concentrations quantified by MSQPCR in indoor and outdoor air sampled simultaneously

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Meklin, Teija; Reponen, Tina; McKinstry, Craig A.

    Mold specific quantitative PCR (MSQPCR) was used to measure the concentrations of 36 mold species in dust and in indoor and in outdoor air samples that were taken simultaneously in 17 homes in Cincinnati with no-known water damage. The total spore concentrations in the indoor (I) and outdoor (O) air samples were statistically significantly different and the concentrations in the three sample types of many of the individual species were significantly different (p < 0.05 based on the Wilcoxon Signed Rank Test). The I/O ratios of the averages or geometric means of the individual species were generally less than 1;more » but these I/O ratios were quite variable ranging from 0.03 for A. sydowii to 1.2 for Acremonium strictum. There were no significant correlations for the 36 specific mold concentrations between the dust samples and the indoor or outdoor air samples (based on the Spearman’s Rho test). The indoor and outdoor air concentrations of 32 of the species were not correlated. Only Aspergillus penicillioides, C. cladosporioides types 1 and 2 and C. herbarum had sufficient data to estimate a correlation at rho > 0.5 with signicance (p < 0.05) In six of these homes, a previous dust sample had been collected and analyzed 2 years earlier. The ERMI© values for the dust samples taken in the same home two years apart were not significantly different (p=0.22) based on Wilcoxon Signed Rank Test.« less

  6. Community Air Sensor Network (CAIRSENSE) project ...

    EPA Pesticide Factsheets

    Advances in air pollution sensor technology have enabled the development of small and low cost systems to measure outdoor air pollution. The deployment of a large number of sensors across a small geographic area would have potential benefits to supplement traditional monitoring networks with additional geographic and temporal measurement resolution, if the data quality were sufficient. To understand the capability of emerging air sensor technology, the Community Air Sensor Network (CAIRSENSE) project deployed low cost, continuous and commercially-available air pollution sensors at a regulatory air monitoring site and as a local sensor network over a surrounding ~2 km area in Southeastern U.S. Co-location of sensors measuring oxides of nitrogen, ozone, carbon monoxide, sulfur dioxide, and particles revealed highly variable performance, both in terms of comparison to a reference monitor as well as whether multiple identical sensors reproduced the same signal. Multiple ozone, nitrogen dioxide, and carbon monoxide sensors revealed low to very high correlation with a reference monitor, with Pearson sample correlation coefficient (r) ranging from 0.39 to 0.97, -0.25 to 0.76, -0.40 to 0.82, respectively. The only sulfur dioxide sensor tested revealed no correlation (r 0.5), step-wise multiple linear regression was performed to determine if ambient temperature, relative humidity (RH), or age of the sensor in sampling days could be used in a correction algorihm to im

  7. Air exposure and sample storage time influence on hydrogen release from tungsten

    NASA Astrophysics Data System (ADS)

    Moshkunov, K. A.; Schmid, K.; Mayer, M.; Kurnaev, V. A.; Gasparyan, Yu. M.

    2010-09-01

    In investigations of hydrogen retention in first wall components the influence of the conditions of the implanted target storage prior to analysis and the storage time is often neglected. Therefore we have performed a dedicated set of experiments. The release of hydrogen from samples exposed to ambient air after irradiation was compared to samples kept in vacuum. For air exposed samples significant amounts of HDO and D 2O are detected during TDS. Additional experiments have shown that heavy water is formed by recombination of releasing D and H atoms with O on the W surface. This water formation can alter hydrogen retention results significantly, in particular - for low retention cases. In addition to the influence of ambient air exposure also the influence of storage time in vacuum was investigated. After implantation at 300 K the samples were stored in vacuum for up to 1 week during which the retained amount decreased significantly. The subsequently measured TDS spectra showed that D was lost from both the high and low energy peaks during storage at ambient temperature of ˜300 K. An attempt to simulate this release from both peaks during room temperature storage by TMAP 7 calculations showed that this effect cannot be explained by conventional diffusion/trapping models.

  8. Sampling and Analyzing Air Pollution: An Apparatus Suitable for Use in Schools.

    ERIC Educational Resources Information Center

    Rockwell, Dean M.; Hansen, Tony

    1994-01-01

    Describes two variations of an air sampler and analyzer that are inexpensive to construct, easy to operate, and designed to be used in an educational program. Variations use vacuum cleaners and aquarium pumps, and white facial tissues serve as filters. Samples of air pollution obtained by this method may be used from early grade school to advanced…

  9. Air Pollution Source/receptor Relationships in South Coast Air Basin, CA

    NASA Astrophysics Data System (ADS)

    Gao, Ning

    This research project includes the application of some existing receptor models to study the air pollution source/receptor relationships in the South Coast Air Basin (SoCAB) of southern California, the development of a new receptor model and the testing and the modifications of some existing models. These existing receptor models used include principal component factor analysis (PCA), potential source contribution function (PSCF) analysis, Kohonen's neural network combined with Prim's minimal spanning tree (TREE-MAP), and direct trilinear decomposition followed by a matrix reconstruction. The ambient concentration measurements used in this study are a subset of the data collected during the 1987 field exercise of Southern California Air Quality Study (SCAQS). It consists of a number of gaseous and particulate pollutants analyzed from samples collected by SCAQS samplers at eight sampling sites, Anaheim, Azusa, Burbank, Claremont, Downtown Los Angeles, Hawthorne, Long Beach, and Rubidoux. Based on the information of emission inventories, meteorology and ambient concentrations, this receptor modeling study has revealed mechanisms that influence the air quality in SoCAB. Some of the mechanisms affecting the air quality in SoCAB that were revealed during this study include the following aspects. The SO_2 collected at sampling sites is mainly contributed by refineries in the coastal area and the ships equipped with oil-fired boilers off shore. Combustion of fossil fuel by automobiles dominates the emission of NO_{rm x} that is subsequently transformed and collected at sampling sites. Electric power plants also contribute HNO_3 to the sampling sites. A large feedlot in the eastern region of SoCAB has been identified as the major source of NH_3. Possible contributions from other industrial sources such as smelters and incinerators were also revealed. The results of this study also suggest the possibility of DMS (dimethylsulfide) and NH_3 emissions from off-shore sediments

  10. EVALUATION OF THE FILTER PACK FOR LONG-DURATION SAMPLING OF AMBIENT AIR

    EPA Science Inventory

    A 14-week filter pack (FP) sampler evaluation field study was conducted at a site near Bondville, IL to investigate the impact of weekly sampling duration. Simultaneous samples were collected using collocated filter packs (FP) from two independent air quality monitoring networks...

  11. Anisotropic shrinkage of insect air sacs revealed in vivo by X-ray microtomography

    NASA Astrophysics Data System (ADS)

    Xu, Liang; Chen, Rongchang; Du, Guohao; Yang, Yiming; Wang, Feixiang; Deng, Biao; Xie, Honglan; Xiao, Tiqiao

    2016-09-01

    Air sacs are thought to be the bellows for insect respiration. However, their exact mechanism of action as a bellows remains unclear. A direct way to investigate this problem is in vivo observation of the changes in their three-dimensional structures. Therefore, four-dimensional X-ray phase contrast microtomography is employed to solve this puzzle. Quantitative analysis of three-dimensional image series reveals that the compression of the air sac during respiration in bell crickets exhibits obvious anisotropic characteristics both longitudinally and transversely. Volumetric changes of the tracheal trunks in the prothorax further strengthen the evidence of this finding. As a result, we conclude that the shrinkage and expansion of the insect air sac is anisotropic, contrary to the hypothesis of isotropy, thereby providing new knowledge for further research on the insect respiratory system.

  12. Passive air sampling of organochlorine pesticides in Mexico.

    PubMed

    Wong, Fiona; Alegria, Henry A; Bidleman, Terry F; Alvarado, Víctor; Angeles, Felipe; Galarza, Alfredo Avila; Bandala, Erick R; Hinojosa, Idolina de la Cerda; Estrada, Ignacio Galindo; Reyes, Guillermo Galindo; Gold-Bouchot, Gerardo; Zamora, Jose Vinicio Macías; Murguía-González, Joaquín; Espinoza, Elias Ramirez

    2009-02-01

    The spatial and temporal variation of organochlorine pesticides (OCs) in air across Mexico was investigated by deploying passive samplers at eleven stations across the country during 2005-2006. Integrated samples were taken over three-month periods and quantified for DDT compounds, endosulfans, toxaphenes, components of technical chlordane, hexachlorocyclohexanes (HCHs), and dieldrin. Enantiomers of chiral chlordanes and o,p'-DDT were determined on chiral stationary phase columns as an indicator of source and age. Results are discussed in combination with pumped air samples taken at four other stations in southern Mexico during 2002-2004. DDT and its metabolites, endosulfan and toxaphene were the most abundant OCs detected in all sampling sites. Atmospheric concentrations of SigmaDDT (p,p'-DDT + o,p'-DDT + p,p'-DDE + o,p'-DDE + p,p'-DDD + o,p'-DDD) ranged from 15 to 2360 pg m(-3) with the highest concentrations found in southern Mexico and the lowest found in northern and central Mexico. A fresher DDT residue was observed at sites with greater DDT use and in the southern part of the country, as shown from the higher FDDTe = p,p'-DDT/(p,p'-DDT + p,p'-DDE) and nearly racemic o,p'-DDT. This agrees with the former heavy use of DDT in the endemic malarious area of the country. A local hotspot of endosulfan was identified at an agricultural area in Mazatlan, Sinaloa, with a annual mean concentration of SigmaENDO (endosulfans I + II + endosulfan sulfate) = 26,800 pg m(-3). At this site, higher concentrations of SigmaENDO were recorded during the winter (November to February) and spring (February to May) periods. From back trajectory analysis, this coincides with a shift in the air mass coming from the Pacific Ocean (May to November) to the inland agricultural area (November to May). The elevated SigmaENDO observed is likely due to the local agricultural usage. HCHs, chlordanes, transnonachlors, and dieldrin were more evenly distributed across the country likely due to

  13. Microbial Air and Surface Monitoring Results from International Space Station Samples

    NASA Technical Reports Server (NTRS)

    Ott, C. Mark; Bruce, Rebekah J.; Castro, Victoria A.; Novikova, Natalia D.; Pierson, D. L.

    2005-01-01

    Over the course of long-duration spaceflight, spacecraft develop a microbial ecology that directly interacts with the crew of the vehicle. While most microorganisms are harmless or beneficial to the inhabitants of the vehicle, the presence of medically significant organisms appearing in this semi-closed environment could adversely affect crew health and performance. The risk of exposure of the crew to medically significant organisms during a mission is estimated using information gathered during nominal and contingency environmental monitoring. Analysis of the air and surface microbiota in the habitable compartments of the International Space Station (ISS) over the last four years indicate a high presence of Staphylococcus species reflecting the human inhabitants of the vehicle. Generally, air and surface microbial concentrations are below system design specifications, suggesting a lower risk of contact infection or biodegradation. An evaluation of sample frequency indicates a decrease in the identification of new species, suggesting a lower potential for unknown microorganisms to be identified. However, the opportunistic pathogen, Staphylococcus aureus, has been identified in 3 of the last 5 air samples and 5 of the last 9 surface samples. In addition, 47% of the coagulase negative Staphylococcus species that were isolated from the crew, ISS, and its hardware were found to be methicillin resistance. In combination, these observations suggest the potential of methicillin resistant infectious agents over time.

  14. Air Sampling Data for BP Spill/Deepwater Horizon

    EPA Pesticide Factsheets

    The Deepwater Horizon oil spill (also referred to as the BP oil spill) began on 20 April 2010 in the Gulf of Mexico on the BP-operated Macondo Prospect. Following the explosion and sinking of the Deepwater Horizon oil rig, a sea-floor oil gusher flowed for 87 days, until it was capped on 15 July 2010.In response to the BP oil spill, EPA sampled air, water, sediment, and waste generated by the cleanup operations.

  15. Trace gas measurements from whole air samples collected over the Antarctic continent

    NASA Technical Reports Server (NTRS)

    Heidt, L. E.; Vedder, J. F.; Pollock, Walter H.; Henry, Bruce E.; Lueb, Richard A.

    1988-01-01

    Whole air samples collected aboard the NASA DC-8 and ER-2 aircraft as part of the Airborne Antarctic Ozone Experiment (AAOE) were analyzed in a field laboratory set up at Punta Arenas, Chile, in August and September, 1987. Mixing ratios obtained from gas chromatographic analyses of these samples are presented for N2O, CFCl3, CFCl2, C2F3Cl3, CH3CCl3, CH4, and CO. Variations in the mixing ratios of these gases along the individual flight paths of the aircraft are used as tracers to indicate the history of air masses over and near the Antarctic continent.

  16. A STRINGENT COMPARISON OF SAMPLING AND ANALYSIS METHODS FOR VOCS IN AMBIENT AIR

    EPA Science Inventory

    A carefully designed study was conducted during the summer of 1998 to simultaneously collect samples of ambient air by canisters and compare the analysis results to direct sorbent preconcentration results taken at the time of sample collection. A total of 32 1-h sample sets we...

  17. Inter-laboratory comparison study on measuring semi-volatile organic chemicals in standards and air samples.

    PubMed

    Su, Yushan; Hung, Hayley

    2010-11-01

    Measurements of semi-volatile organic chemicals (SVOCs) were compared among 21 laboratories from 7 countries through the analysis of standards, a blind sample, an air extract, and an atmospheric dust sample. Measurement accuracy strongly depended on analytes, laboratories, and types of standards and samples. Intra-laboratory precision was generally good with relative standard deviations (RSDs) of triplicate injections <10% and with median differences of duplicate samples between 2.1 and 22%. Inter-laboratory variability, measured by RSDs of all measurements, was in the range of 2.8-58% in analyzing standards, and 6.9-190% in analyzing blind sample and air extract. Inter-laboratory precision was poorer when samples were subject to cleanup processes, or when SVOCs were quantified at low concentrations. In general, inter-laboratory differences up to a factor of 2 can be expected to analyze atmospheric SVOCs. When comparing air measurements from different laboratories, caution should be exercised if the data variability is less than the inter-laboratory differences. 2010. Published by Elsevier Ltd. All rights reserved.

  18. Reliability of air displacement plethysmography in a large, heterogeneous sample.

    PubMed

    Noreen, Eric E; Lemon, Peter W R

    2006-08-01

    Several studies have assessed the validity of air displacement plethysmography (ADP), but few have assessed the reliability of ADP using a large, heterogeneous sample. This study was conducted to determine the reliability of ADP using the Bod Pod in a large, heterogeneous sample. A total of 980 healthy men and women (30 +/- 15 yr, mean +/- SD) completed two body composition assessments separated by 15-30 min. All testing was done in accordance with the manufacturer's instructions. A significant correlation (r = 0.992, P = 0.001) was found between body density (BD) 1 (1.046 +/- 0.001 kg.L(-1); mean +/- SEM) and BD 2 (1.046 +/- 0.001 kg.L(-1). A paired t-test revealed no significant difference between BD 1 and 2 (P = 0.935). The coefficient of variation (CV) for BD was 0.15%. A significant intraclass correlation coefficient (ICC) was found for BD (ICC = 0.996, P = 0.001), and the standard error of measurement (SEM) was 0.001 kg.L(-1). Body mass (BM) 1 and 2 were correlated significantly (r = 0.999, P = 0.001); however, a significant (P = 0.001) decrease was seen from BM 1 (75.510 +/- 0.461 kg) to BM 2 (75.497 +/- 0.461 kg). Body volume (BV) tended to decrease (P = 0.08) from BV 1 (69.900 +/- 0.449 L) to BV 2 (69.884 +/- 0.449 L). ADP using the Bod Pod appears to assess BD reliably; however, the observed CV suggests that multiple trials are necessary to detect small treatment effects.

  19. 2018 Annual Terrestrial Sampling Plan for Sandia National Laboratories/New Mexico on Kirtland Air Force Base.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Griffith, Stacy R.

    The 2018 Annual Terrestrial Sampling Plan for Sandia National Laboratories/New Mexico on Kirtland Air Force Base has been prepared in accordance with the “Letter of Agreement Between Department of Energy, National Nuclear Security Administration, Sandia Field Office (DOE/NNSA/SFO) and 377th Air Base Wing (ABW), Kirtland Air Force Base (KAFB) for Terrestrial Sampling” (signed January 2017), Sandia National Laboratories, New Mexico (SNL/NM). The Letter of Agreement requires submittal of an annual terrestrial sampling plan.

  20. 2017 Annual Terrestrial Sampling Plan for Sandia National Laboratories/New Mexico on Kirtland Air Force Base

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Griffith, Stacy R.

    The 2017 Annual Terrestrial Sampling Plan for Sandia National Laboratories/New Mexico on Kirtland Air Force Base has been prepared in accordance with the “Letter of Agreement Between Department of Energy, National Nuclear Security Administration, Sandia Field Office (DOE/NNSA/SFO) and 377th Air Base Wing (ABW), Kirtland Air Force Base (KAFB) for Terrestrial Sampling” (signed January 2017), Sandia National Laboratories, New Mexico (SNL/NM). The Letter of Agreement requires submittal of an annual terrestrial sampling plan.

  1. A survey of recent results in passive sampling of water and air by semipermeable membrane devices

    USGS Publications Warehouse

    Prest, Harry F.; Huckins, James N.; Petty, Jimmie D.; Herve, Sirpa; Paasivirta, Jaakko; Heinonen, Pertti

    1995-01-01

    A survey is presented of some recent results for passive sampling of water and air for trace organic contaminants using lipid-filled semipermeable membrane devices (SPMDs). Results of water sampling for trace organochlorine compounds using simultaneously exposed SPMDs and the most universally applied biomonitor (bivalves) are discussed. In general, the total amounts of accumulated analytes available for analysis in bivalves and SPMDs were comparable. However, SPMD controls typically had negligible levels of contamination, which was not always the case for transplanted bivalves, even after prolonged depuration prior to exposure. In surveys of the spatial trends of organochlorines at a series of sites, data from bivalves and SPMDs provided the same picture of contaminant distribution and severity. An exception was ionizable contaminants such as the chlorinated phenolic compounds and their transformation products found in pulp mill effluents. In these cases the two monitoring approaches compliment each other, i.e. what is not found in bivalves appears in SPMDs and vice versa. SPMDs have also been applied in environments where biomonitoring is not feasible. SPMDs have shown their utility in studies of trace levels of polyaromatic hydrocarbons by locating and characterizing point sources. An example is given of their application to the calculation of contaminant half-lives from aqueous SPMD residues, a direct measurement of the persistence of contaminants in an environmental compartment. Similarly, results of air sampling with SPMDs in a relatively pristine coastal location are cited which reveal a tremendous enhancement in p,p′-DDE relative to open ocean values.

  2. Early Detection of Foot-And-Mouth Disease Virus from Infected Cattle Using A Dry Filter Air Sampling System.

    PubMed

    Pacheco, J M; Brito, B; Hartwig, E; Smoliga, G R; Perez, A; Arzt, J; Rodriguez, L L

    2017-04-01

    Foot-and-mouth disease (FMD) is a highly contagious livestock disease of high economic impact. Early detection of FMD virus (FMDV) is fundamental for rapid outbreak control. Air sampling collection has been demonstrated as a useful technique for detection of FMDV RNA in infected animals, related to the aerogenous nature of the virus. In the current study, air from rooms housing individual (n = 17) or two groups (n = 4) of cattle experimentally infected with FDMV A24 Cruzeiro of different virulence levels was sampled to assess the feasibility of applying air sampling as a non-invasive, screening tool to identify sources of FMDV infection. Detection of FMDV RNA in air was compared with first detection of clinical signs and FMDV RNA levels in serum and oral fluid. FMDV RNA was detected in room air samples 1-3 days prior (seven animals) or on the same day (four animals) as the appearance of clinical signs in 11 of 12 individually housed cattle. Only in one case clinical signs preceded detection in air samples by one day. Overall, viral RNA in oral fluid or serum preceded detection in air samples by 1-2 days. Six individually housed animals inoculated with attenuated strains did not show clinical signs, but virus was detected in air in one of these cases 3 days prior to first detection in oral fluid. In groups of four cattle housed together, air detection always preceded appearance of clinical signs by 1-2 days and coincided more often with viral shedding in oral fluid than virus in blood. These data confirm that air sampling is an effective non-invasive screening method for detecting FMDV infection in confined to enclosed spaces (e.g. auction barns, milking parlours). This technology could be a useful tool as part of a surveillance strategy during FMD prevention, control or eradication efforts. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  3. Bioassay vs. Air Sampling: Practical Guidance and Experience at Hanford

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Carbaugh, Eugene H.; Carlson, Eric W.; Hill, Robin L.

    2004-02-08

    The Hanford Site has implemented a policy to guide in determining whether air sampling data or special fecal bioassay data are more appropriate for determining doses of record for low-level plutonium exposures. The basis for the policy and four years of experience in comparing DAC-hours exposure with bioassay-based dosimetry is discussed.

  4. Diagnosis of ambient air pollution injury to red maple leaves

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Krause, C.R.

    1981-01-01

    Ramets of red maple, Acer rubrum L. (cv 'Scarlet Sentinel') were grown under ambient field conditions for 5 months (May-Sept) in either clean air (i.e. minimum background of ozone (O/sub 3/) and sulfur dioxide (SO/sub 2/)) or were grown in polluted air containing phytotoxic combinations of O/sub 3/ and SO/sub 2/. At the end of the growing season leaf samples from each site were fixed in glutaraldehyde, washed in buffer (3X) post-fixed in O/sub s/O/sub 4/, dehydrated in ethanol and critically-point-dried. Samples were fractured with a razor blade, mounted either abaxially or adaxially or in cross-section, and sputter-coated with Au.more » While plants from either site failed to exhibit macroscopic air pollutant-induced symptoms, SEM examination revealed significant microscopic differences between prepared samples from different sites. Epidermal cells of leaves grown in clean air were uniformly turgid with fluffy epicuticular wax. Leaf samples from ramets that were grown in polluted air exhibited collapsed epidermal cells and lacked fluffy epicuticular wax. Cross-sections revealed increased vesicular activity in leaf mesophyll cells of plants exposed to high ambient pollution while cells of plants grown in clean air appeared normal. 10 references, 6 figures.« less

  5. Air sampling results in relation to extent of fungal colonization of building materials in some water-damaged buildings.

    PubMed

    Miller, J D; Haisley, P D; Reinhardt, J H

    2000-09-01

    We studied the extent and nature of fungal colonization of building materials in 58 naturally ventilated apartments that had suffered various kinds of water damage in relation to air sampling done before the physical inspections. The results of air samples from each apartment were compared by rank order of species with pooled data from outdoor air. Approximately 90% of the apartments that had significant amounts of fungi in wall cavities were identified by air sampling. There was no difference in the average fungal colony forming unit values per m3 between the 15 apartments with the most fungal contamination and the 15 with the least. In contrast, the prevalence of samples with fungal species significantly different than the pooled outdoor air between the more contaminated versus the less contaminated apartments was approximately 10-fold. We provide information on methods to document fungal contamination in buildings.

  6. Air sampling procedures to evaluate microbial contamination: a comparison between active and passive methods in operating theatres.

    PubMed

    Napoli, Christian; Marcotrigiano, Vincenzo; Montagna, Maria Teresa

    2012-08-02

    Since air can play a central role as a reservoir for microorganisms, in controlled environments such as operating theatres regular microbial monitoring is useful to measure air quality and identify critical situations. The aim of this study is to assess microbial contamination levels in operating theatres using both an active and a passive sampling method and then to assess if there is a correlation between the results of the two different sampling methods. The study was performed in 32 turbulent air flow operating theatres of a University Hospital in Southern Italy. Active sampling was carried out using the Surface Air System and passive sampling with settle plates, in accordance with ISO 14698. The Total Viable Count (TVC) was evaluated at rest (in the morning before the beginning of surgical activity) and in operational (during surgery). The mean TVC at rest was 12.4 CFU/m3 and 722.5 CFU/m2/h for active and passive samplings respectively. The mean in operational TVC was 93.8 CFU/m3 (SD = 52.69; range = 22-256) and 10496.5 CFU/m2/h (SD = 7460.5; range = 1415.5-25479.7) for active and passive samplings respectively. Statistical analysis confirmed that the two methods correlate in a comparable way with the quality of air. It is possible to conclude that both methods can be used for general monitoring of air contamination, such as routine surveillance programs. However, the choice must be made between one or the other to obtain specific information.

  7. Salmonella recovery following air chilling for matched neck-skin and whole carcass sampling methodologies

    USDA-ARS?s Scientific Manuscript database

    The prevalence and serogroups of Salmonella recovered following air chilling were determined for both enriched neck skin and matching enriched whole carcass samples. Commercially processed and eviscerated carcasses were air chilled to 4C before removing the neck skin (8.3 g) and stomaching in 83 mL...

  8. Sorbent-based sampling methods for volatile and semi-volatile organic compounds in air. Part 2. Sorbent selection and other aspects of optimizing air monitoring methods.

    PubMed

    Woolfenden, Elizabeth

    2010-04-16

    Sorbent tubes/traps are widely used in combination with gas chromatographic (GC) analytical methods to monitor the vapour-phase fraction of organic compounds in air. Applications range from atmospheric research and ambient air monitoring (indoor and outdoor) to occupational hygiene (personal exposure assessment) and measuring chemical emission levels. Part 1 of this paper reviewed the main sorbent-based air sampling strategies including active (pumped) tube monitoring, diffusive (passive) sampling onto sorbent tubes/cartridges plus sorbent trapping/focusing of whole air samples that are either collected in containers (such as canisters or bags) or monitored online. Options for subsequent extraction and transfer to GC(MS) analysis were also summarised and the trend to thermal desorption (TD)-based methods and away from solvent extraction was explained. As a result of this trend, demand for TD-compatible sorbents (alternatives to traditional charcoal) is growing. Part 2 of this paper therefore continues with a summary of TD-compatible sorbents, their respective advantages and limitations and considerations for sorbent selection. Other analytical considerations for optimizing sorbent-based air monitoring methods are also discussed together with recent technical developments and sampling accessories which have extended the application range of sorbent trapping technology generally. Copyright 2010 Elsevier B.V. All rights reserved.

  9. Airborne detection and quantification of swine influenza a virus in air samples collected inside, outside and downwind from swine barns.

    PubMed

    Corzo, Cesar A; Culhane, Marie; Dee, Scott; Morrison, Robert B; Torremorell, Montserrat

    2013-01-01

    Airborne transmission of influenza A virus (IAV) in swine is speculated to be an important route of virus dissemination, but data are scarce. This study attempted to detect and quantify airborne IAV by virus isolation and RRT-PCR in air samples collected under field conditions. This was accomplished by collecting air samples from four acutely infected pig farms and locating air samplers inside the barns, at the external exhaust fans and downwind from the farms at distances up to 2.1 km. IAV was detected in air samples collected in 3 out of 4 farms included in the study. Isolation of IAV was possible from air samples collected inside the barn at two of the farms and in one farm from the exhausted air. Between 13% and 100% of samples collected inside the barns tested RRT-PCR positive with an average viral load of 3.20E+05 IAV RNA copies/m³ of air. Percentage of exhaust positive air samples also ranged between 13% and 100% with an average viral load of 1.79E+04 RNA copies/m³ of air. Influenza virus RNA was detected in air samples collected between 1.5 and 2.1 Km away from the farms with viral levels significantly lower at 4.65E+03 RNA copies/m³. H1N1, H1N2 and H3N2 subtypes were detected in the air samples and the hemagglutinin gene sequences identified in the swine samples matched those in aerosols providing evidence that the viruses detected in the aerosols originated from the pigs in the farms under study. Overall our results indicate that pigs can be a source of IAV infectious aerosols and that these aerosols can be exhausted from pig barns and be transported downwind. The results from this study provide evidence of the risk of aerosol transmission in pigs under field conditions.

  10. Airborne Detection and Quantification of Swine Influenza A Virus in Air Samples Collected Inside, Outside and Downwind from Swine Barns

    PubMed Central

    Corzo, Cesar A.; Culhane, Marie; Dee, Scott; Morrison, Robert B.; Torremorell, Montserrat

    2013-01-01

    Airborne transmission of influenza A virus (IAV) in swine is speculated to be an important route of virus dissemination, but data are scarce. This study attempted to detect and quantify airborne IAV by virus isolation and RRT-PCR in air samples collected under field conditions. This was accomplished by collecting air samples from four acutely infected pig farms and locating air samplers inside the barns, at the external exhaust fans and downwind from the farms at distances up to 2.1 km. IAV was detected in air samples collected in 3 out of 4 farms included in the study. Isolation of IAV was possible from air samples collected inside the barn at two of the farms and in one farm from the exhausted air. Between 13% and 100% of samples collected inside the barns tested RRT-PCR positive with an average viral load of 3.20E+05 IAV RNA copies/m3 of air. Percentage of exhaust positive air samples also ranged between 13% and 100% with an average viral load of 1.79E+04 RNA copies/m3 of air. Influenza virus RNA was detected in air samples collected between 1.5 and 2.1 Km away from the farms with viral levels significantly lower at 4.65E+03 RNA copies/m3. H1N1, H1N2 and H3N2 subtypes were detected in the air samples and the hemagglutinin gene sequences identified in the swine samples matched those in aerosols providing evidence that the viruses detected in the aerosols originated from the pigs in the farms under study. Overall our results indicate that pigs can be a source of IAV infectious aerosols and that these aerosols can be exhausted from pig barns and be transported downwind. The results from this study provide evidence of the risk of aerosol transmission in pigs under field conditions. PMID:23951164

  11. Air sampling procedures to evaluate microbial contamination: a comparison between active and passive methods in operating theatres

    PubMed Central

    2012-01-01

    Background Since air can play a central role as a reservoir for microorganisms, in controlled environments such as operating theatres regular microbial monitoring is useful to measure air quality and identify critical situations. The aim of this study is to assess microbial contamination levels in operating theatres using both an active and a passive sampling method and then to assess if there is a correlation between the results of the two different sampling methods. Methods The study was performed in 32 turbulent air flow operating theatres of a University Hospital in Southern Italy. Active sampling was carried out using the Surface Air System and passive sampling with settle plates, in accordance with ISO 14698. The Total Viable Count (TVC) was evaluated at rest (in the morning before the beginning of surgical activity) and in operational (during surgery). Results The mean TVC at rest was 12.4 CFU/m3 and 722.5 CFU/m2/h for active and passive samplings respectively. The mean in operational TVC was 93.8 CFU/m3 (SD = 52.69; range = 22-256) and 10496.5 CFU/m2/h (SD = 7460.5; range = 1415.5-25479.7) for active and passive samplings respectively. Statistical analysis confirmed that the two methods correlate in a comparable way with the quality of air. Conclusion It is possible to conclude that both methods can be used for general monitoring of air contamination, such as routine surveillance programs. However, the choice must be made between one or the other to obtain specific information. PMID:22853006

  12. Breakthrough of 1,3-dichloropropene and chloropicrin from 600 mg XAD-4 air sampling tubes

    USDA-ARS?s Scientific Manuscript database

    Accurately measuring air concentrations of agricultural fumigants is important for the regulation of air quality. Understanding the conditions under which sorbent tubes can effectively retain such fumigants during sampling is critical in mitigating chemical breakthrough from the tubes and facilitati...

  13. Ozone measurement system for NASA global air sampling program

    NASA Technical Reports Server (NTRS)

    Tiefermann, M. W.

    1979-01-01

    The ozone measurement system used in the NASA Global Air Sampling Program is described. The system uses a commercially available ozone concentration monitor that was modified and repackaged so as to operate unattended in an aircraft environment. The modifications required for aircraft use are described along with the calibration techniques, the measurement of ozone loss in the sample lines, and the operating procedures that were developed for use in the program. Based on calibrations with JPL's 5-meter ultraviolet photometer, all previously published GASP ozone data are biased high by 9 percent. A system error analysis showed that the total system measurement random error is from 3 to 8 percent of reading (depending on the pump diaphragm material) or 3 ppbv, whichever are greater.

  14. Variables Related to Pre-Service Cannabis Use in a Sample of Air Force Enlistees.

    ERIC Educational Resources Information Center

    Mullins, Cecil J.; And Others

    This report is an attempt to add to the existing information about cannabis use, its correlates, and its effects. The sample population consisted of self-admitted abusers of various drugs, identified shortly after entering the Air Force. The subjects (N=4688) were located through the Drug Control Office at Lackland Air Force Base. Variables…

  15. Modeling and Qualification of a Modified Emission Unit for Radioactive Air Emissions Stack Sampling Compliance.

    PubMed

    Barnett, J Matthew; Yu, Xiao-Ying; Recknagle, Kurtis P; Glissmeyer, John A

    2016-11-01

    A planned laboratory space and exhaust system modification to the Pacific Northwest National Laboratory Material Science and Technology Building indicated that a new evaluation of the mixing at the air sampling system location would be required for compliance to ANSI/HPS N13.1-2011. The modified exhaust system would add a third fan, thereby increasing the overall exhaust rate out the stack, thus voiding the previous mixing study. Prior to modifying the radioactive air emissions exhaust system, a three-dimensional computational fluid dynamics computer model was used to evaluate the mixing at the sampling system location. Modeling of the original three-fan system indicated that not all mixing criteria could be met. A second modeling effort was conducted with the addition of an air blender downstream of the confluence of the three fans, which then showed satisfactory mixing results. The final installation included an air blender, and the exhaust system underwent full-scale tests to verify velocity, cyclonic flow, gas, and particulate uniformity. The modeling results and those of the full-scale tests show agreement between each of the evaluated criteria. The use of a computational fluid dynamics code was an effective aid in the design process and allowed the sampling system to remain in its original location while still meeting the requirements for sampling at a well mixed location.

  16. Passive Samplers for Investigations of Air Quality: Method Description, Implementation, and Comparison to Alternative Sampling Methods

    EPA Science Inventory

    This Paper covers the basics of passive sampler design, compares passive samplers to conventional methods of air sampling, and discusses considerations when implementing a passive sampling program. The Paper also discusses field sampling and sample analysis considerations to ensu...

  17. Dengue Virus 1 Outbreak in Buenos Aires, Argentina, 2016.

    PubMed

    Tittarelli, Estefanía; Lusso, Silvina B; Goya, Stephanie; Rojo, Gabriel L; Natale, Mónica I; Viegas, Mariana; Mistchenko, Alicia S; Valinotto, Laura E

    2017-10-01

    The largest outbreak of dengue in Buenos Aires, Argentina, occurred during 2016. Phylogenetic, phylodynamic, and phylogeographic analyses of 82 samples from dengue patients revealed co-circulation of 2 genotype V dengue virus lineages, suggesting that this virus has become endemic to the Buenos Aires metropolitan area.

  18. TECHNOLOGY EVALUATION REPORT CEREX ENVIRONMENTAL SERVICES UV HOUND POINT SAMPLE AIR MONITOR

    EPA Science Inventory

    The USEPA's National Homeland Security Research Center (NHSRC) Technology Testing and Evaluation Program (TTEP) is carrying out performance tests on homeland security technologies. Under TTEP, Battelle evaluated the performance of the Cerex UV Hound point sample air monitor in de...

  19. Comparison of indoor air sampling and dust collection methods for fungal exposure assessment using quantitative PCR

    EPA Science Inventory

    Evaluating fungal contamination indoors is complicated because of the many different sampling methods utilized. In this study, fungal contamination was evaluated using five sampling methods and four matrices for results. The five sampling methods were a 48 hour indoor air sample ...

  20. Scheduling whole-air samples above the Trade Wind Inversion from SUAS using real-time sensors

    NASA Astrophysics Data System (ADS)

    Freer, J. E.; Greatwood, C.; Thomas, R.; Richardson, T.; Brownlow, R.; Lowry, D.; MacKenzie, A. R.; Nisbet, E. G.

    2015-12-01

    Small Unmanned Air Systems (SUAS) are increasingly being used in science applications for a range of applications. Here we explore their use to schedule the sampling of air masses up to 2.5km above ground using computer controlled bespoked Octocopter platforms. Whole-air sampling is targeted above, within and below the Trade Wind Inversion (TWI). On-board sensors profiled the TWI characteristics in real time on ascent and, hence, guided the altitudes at which samples were taken on descent. The science driver for this research is investigation of the Southern Methane Anomaly and, more broadly, the hemispheric-scale transport of long-lived atmospheric tracers in the remote troposphere. Here we focus on the practical application of SUAS for this purpose. Highlighting the need for mission planning, computer control, onboard sensors and logistics in deploying such technologies for out of line-of-sight applications. We show how such a platform can be deployed successfully, resulting in some 60 sampling flights within a 10 day period. Challenges remain regarding the deployment of such platforms routinely and cost-effectively, particularly regarding training and support. We present some initial results from the methane sampling and its implication for exploring and understanding the Southern Methane Anomaly.

  1. DEVELOPMENT OF A SUB-SLAB AIR SAMPLING PROTOCOL TO SUPPORT ASSESSMENT OF VAPOR INTRUSION

    EPA Science Inventory

    The primary purpose of this research effort is to develop a methodology for sub-slab sampling to support the EPA guidance and vapor intrusion investigations after vapor intrusion has been established at a site. Methodologies for sub-slab air sampling are currently lacking in ref...

  2. Avian influenza H9N2 virus isolated from air samples in LPMs in Jiangxi, China.

    PubMed

    Zeng, Xiaoxu; Liu, Mingbin; Zhang, Heng; Wu, Jingwen; Zhao, Xiang; Chen, Wenbing; Yang, Lei; He, Fenglan; Fan, Guoyin; Wang, Dayan; Chen, Haiying; Shu, Yuelong

    2017-07-24

    Recently, avian influenza virus has caused repeated worldwide outbreaks in humans. Live Poultry Markets (LPMs) play an important role in the circulation and reassortment of novel Avian Influenza Virus (AIVs). Aerosol transmission is one of the most important pathways for influenza virus to spread among poultry, from poultry to mammals, and among mammals. In this study, air samples were collected from LPMs in Nanchang city between April 2014 and March 2015 to investigate possible aerosol transmission of AIVs. Air samples were detected for Flu A by Real-Time Reverse Transcription-Polymerase Chain Reaction (RRT-PCR). If samples were positive for Flu A, they were inoculated into 9- to 10-day-old specific-pathogen-free embryonated eggs. If the result was positive, the whole genome of the virus was sequenced by MiSeq. Phylogenetic trees of all 8 segments were constructed using MEGA 6.05 software. To investigate the possible aerosol transmission of AIVs, 807 air samples were collected from LPMs in Nanchang city between April 2014 and March 2015. Based on RRT-PCR results, 275 samples (34.1%) were Flu A positive, and one virus was successfully isolated with embryonated eggs. The virus shared high nucleotide homology with H9N2 AIVs from South China. Our study provides further evidence that the air in LPMs can be contaminated by influenza viruses and their nucleic acids, and this should be considered when choosing and evaluating disinfection strategies in LPMs, such as regular air disinfection. Aerosolized viruses such as the H9N2 virus detected in this study can increase the risk of human infection when people are exposed in LPMs.

  3. Comparison of stationary and personal air sampling with an air dispersion model for children’s ambient exposure to manganese

    EPA Science Inventory

    Manganese (Mn) is ubiquitous in the environment and essential for normal growth and development, yet excessive exposure can lead to impairments in neurological function. This study modeled ambient Mn concentrations as an alternative to stationary and personal air sampling to asse...

  4. Use of alpha spectroscopy for conducting rapid surveys of transuranic activity on air sample filters and smears.

    PubMed

    Hayes, Robert B; Peña, Adan M; Goff, Thomas E

    2005-08-01

    This paper demonstrates the utility of a portable alpha Continuous Air Monitor (CAM) as a bench top scalar counter for multiple sample types. These include using the CAM to count fixed air sample filters and radiological smears. In counting radiological smears, the CAM is used very much like a gas flow proportional counter (GFPC), albeit with a lower efficiency. Due to the typically low background in this configuration, the minimum detectable activity for a 5-min count should be in the range of about 10 dpm which is acceptably below the 20 dpm limit for transuranic isotopes. When counting fixed air sample filters, the CAM algorithm along with other measurable characteristics can be used to identify and quantify the presence of transuranic isotopes in the samples. When the radiological control technician wants to take some credit from naturally occurring radioactive material contributions due to radon progeny producing higher energy peaks (as in the case with a fixed air sample filter), then more elaborate techniques are required. The techniques presented here will generate a decision level of about 43 dpm for such applications. The calibration for this application should alternatively be done using the default values of channels 92-126 for region of interest 1. This can be done within 10 to 15 min resulting in a method to rapidly evaluate air filters for transuranic activity. When compared to the 1-h count technique described by , the technique presented in the present work demonstrates a technique whereby more than two thirds of samples can be rapidly shown (within 10 to 15 min) to be within regulatory compliant limits. In both cases, however, spectral quality checks are required to insure sample self attenuation is not a significant bias in the activity estimates. This will allow the same level of confidence when using these techniques for activity quantification as is presently available for air monitoring activity quantification using CAMs.

  5. Spectral fingerprinting of polycyclic aromatic hydrocarbons in high-volume ambient air samples by constant energy synchronous luminescence spectroscopy

    USGS Publications Warehouse

    Kerkhoff, M.J.; Lee, T.M.; Allen, E.R.; Lundgren, D.A.; Winefordner, J.D.

    1985-01-01

    A high-volume sampler fitted with a glass-fiber filter and backed by polyurethane foam (PUF) was employed to collect airborne particulate and gas-phase polycylic aromatic hydrocarbons (PAHs) in ambient air. Samples were collected from four sources representing a range of environmental conditions: gasoline engine exhaust, diesel engine exhaust, air near a heavily traveled interstate site, and air from a moderately polluted urban site. Spectral fingerprints of the unseparated particulate and gas-phase samples were obtained by constant energy synchronous luminescence spectroscopy (CESLS). Five major PAHs in the gas-phase extracts were characterized and estimated. The compatibility of a high-volume sampling method using polyurethane foam coupled with CESLS detection is explored for use as a screening technique for PAHs in ambient air. ?? 1985 American Chemical Society.

  6. Occurrence and quantitative microbial risk assessment of Cryptosporidium and Giardia in soil and air samples.

    PubMed

    Balderrama-Carmona, Ana Paola; Gortáres-Moroyoqui, Pablo; Álvarez-Valencia, Luis Humberto; Castro-Espinoza, Luciano; Mondaca-Fernández, Iram; Balderas-Cortés, José de Jesús; Chaidez-Quiroz, Cristóbal; Meza-Montenegro, María Mercedes

    2014-09-01

    Cryptosporidium oocysts and Giardia cysts can be transmitted by the fecal-oral route and may cause gastrointestinal parasitic zoonoses. These zoonoses are common in rural zones due to the parasites being harbored in fecally contaminated soil. This study assessed the risk of illness (giardiasis and cryptosporidiosis) from inhaling and/or ingesting soil and/or airborne dust in Potam, Mexico. To assess the risk of infection, Quantitative Microbial Risk Assessment (QMRA) was employed, with the following steps: (1) hazard identification, (2) hazard exposure, (3) dose-response, and (4) risk characterization. Cryptosporidium oocysts and Giardia cysts were observed in 52% and 57%, respectively, of total soil samples (n=21), and in 60% and 80%, respectively, of air samples (n=12). The calculated annual risks were higher than 9.9 × 10(-1) for both parasites in both types of sample. Soil and air inhalation and/or ingestion are important vehicles for these parasites. To our knowledge, the results obtained in the present study represent the first QMRAs for cryptosporidiosis and giardiasis due to soil and air inhalation/ingestion in Mexico. In addition, this is the first evidence of the microbial air quality around these parasites in rural zones. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. High-resolution real-time optical studies of radiological air sample filtration processes in an environmental continuous air monitor

    NASA Astrophysics Data System (ADS)

    Rodgers, John C.; Wasiolek, Piotr T.; Schery, Stephen D.; Alcantara, Raul E.

    1999-01-01

    The need for a continuous air monitor capable of quick and accurate measurements of airborne radioactivity in close proximity to the work environment during waste management, site restoration, and D&D operations led to the Los Alamos National Laboratory development of an environmental continuous air monitor (ECAM). Monitoring the hostile work environment of waste recovery, for example, presents unique challenges for detector design for detectors previously used for the clean room conditions of the typical plutonium laboratory. The environmental and atmospheric conditions (dust, high wind, etc.) influence aerosol particle penetration into the ECAM sampling head as well as the build-up of deposits on the ECAM filter.

  8. Size selective isocyanate aerosols personal air sampling using porous plastic foams

    NASA Astrophysics Data System (ADS)

    Khanh Huynh, Cong; Duc, Trinh Vu

    2009-02-01

    As part of a European project (SMT4-CT96-2137), various European institutions specialized in occupational hygiene (BGIA, HSL, IOM, INRS, IST, Ambiente e Lavoro) have established a program of scientific collaboration to develop one or more prototypes of European personal samplers for the collection of simultaneous three dust fractions: inhalable, thoracic and respirable. These samplers based on existing sampling heads (IOM, GSP and cassettes) use Polyurethane Plastic Foam (PUF) according to their porosity to support sampling and separator size of the particles. In this study, the authors present an original application of size selective personal air sampling using chemical impregnated PUF to perform isocyanate aerosols capturing and derivatizing in industrial spray-painting shops.

  9. Optimization of sampling parameters for collection and preconcentration of alveolar air by needle traps.

    PubMed

    Filipiak, Wojciech; Filipiak, Anna; Ager, Clemens; Wiesenhofer, Helmut; Amann, Anton

    2012-06-01

    The approach for breath-VOCs' collection and preconcentration by applying needle traps was developed and optimized. The alveolar air was collected from only a few exhalations under visual control of expired CO(2) into a large gas-tight glass syringe and then warmed up to 45 °C for a short time to avoid condensation. Subsequently, a specially constructed sampling device equipped with Bronkhorst® electronic flow controllers was used for automated adsorption. This sampling device allows time-saving collection of expired/inspired air in parallel onto three different needle traps as well as improvement of sensitivity and reproducibility of NT-GC-MS analysis by collection of relatively large (up to 150 ml) volume of exhaled breath. It was shown that the collection of alveolar air derived from only a few exhalations into a large syringe followed by automated adsorption on needle traps yields better results than manual sorption by up/down cycles with a 1 ml syringe, mostly due to avoided condensation and electronically controlled stable sample flow rate. The optimal profile and composition of needle traps consists of 2 cm Carbopack X and 1 cm Carboxen 1000, allowing highly efficient VOCs' enrichment, while injection by a fast expansive flow technique requires no modifications in instrumentation and fully automated GC-MS analysis can be performed with a commercially available autosampler. This optimized analytical procedure considerably facilitates the collection and enrichment of alveolar air, and is therefore suitable for application at the bedside of critically ill patients in an intensive care unit. Due to its simplicity it can replace the time-consuming sampling of sufficient breath volume by numerous up/down cycles with a 1 ml syringe.

  10. Monte Carlo simulation of air sampling methods for the measurement of radon decay products.

    PubMed

    Sima, Octavian; Luca, Aurelian; Sahagia, Maria

    2017-08-01

    A stochastic model of the processes involved in the measurement of the activity of the 222 Rn decay products was developed. The distributions of the relevant factors, including air sampling and radionuclide collection, are propagated using Monte Carlo simulation to the final distribution of the measurement results. The uncertainties of the 222 Rn decay products concentrations in the air are realistically evaluated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Reveal Listeria 2.0 test for detection of Listeria spp. in foods and environmental samples.

    PubMed

    Alles, Susan; Curry, Stephanie; Almy, David; Jagadeesan, Balamurugan; Rice, Jennifer; Mozola, Mark

    2012-01-01

    A Performance Tested Method validation study was conducted for a new lateral flow immunoassay (Reveal Listeria 2.0) for detection of Listeria spp. in foods and environmental samples. Results of inclusivity testing showed that the test detects all species of Listeria, with the exception of L. grayi. In exclusivity testing conducted under nonselective growth conditions, all non-listeriae tested produced negative Reveal assay results, except for three strains of Lactobacillus spp. However, these lactobacilli are inhibited by the selective Listeria Enrichment Single Step broth enrichment medium used with the Reveal method. Six foods were tested in parallel by the Reveal method and the U.S. Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) reference culture procedure. Considering data from both internal and independent laboratory trials, overall sensitivity of the Reveal method relative to that of the FDA/BAM procedure was 101%. Four foods were tested in parallel by the Reveal method and the U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) reference culture procedure. Overall sensitivity of the Reveal method relative to that of the USDA-FSIS procedure was 98.2%. There were no statistically significant differences in the number of positives obtained by the Reveal and reference culture procedures in any food trials. In testing of swab or sponge samples from four types of environmental surfaces, sensitivity of Reveal relative to that of the USDA-FSIS reference culture procedure was 127%. For two surface types, differences in the number of positives obtained by the Reveal and reference methods were statistically significant, with more positives by the Reveal method in both cases. Specificity of the Reveal assay was 100%, as there were no unconfirmed positive results obtained in any phase of the testing. Results of ruggedness experiments showed that the Reveal assay is tolerant of modest deviations in test sample volume and

  12. Use of Whatman-41 filters in air quality sampling networks (with applications to elemental analysis)

    NASA Technical Reports Server (NTRS)

    Neustadter, H. E.; Sidik, S. M.; King, R. B.; Fordyce, J. S.; Burr, J. C.

    1974-01-01

    The operation of a 16-site parallel high volume air sampling network with glass fiber filters on one unit and Whatman-41 filters on the other is reported. The network data and data from several other experiments indicate that (1) Sampler-to-sampler and filter-to-filter variabilities are small; (2) hygroscopic affinity of Whatman-41 filters need not introduce errors; and (3) suspended particulate samples from glass fiber filters averaged slightly, but not statistically significantly, higher than from Whatman-41-filters. The results obtained demonstrate the practicability of Whatman-41 filters for air quality monitoring and elemental analysis.

  13. Residues of 2, 4-D in air samples from Saskatchewan: 1966-1975.

    PubMed

    Grover, R; Kerr, L A; Wallace, K; Yoshida, K; Maybank, J

    1976-01-01

    Residues of 2,4-D (2,4-dichlorophenoxyacetic acid) in air samples from several sampling sites in central and southern Saskatchewan during the spraying seasons in the 1966-68 and 1970-75 periods were determined by gas-liquid chromatographic techniques. Initially, individual esters of 2,4-D were characterized by retention times and confirmed further by co-injection and dual column procedures. Since 1973, however, only total 2,4-D acid levels in air samples have been determined after esterification to the methyl ester and confirmed by gc/ms techniques whenever possible. Up to 50% of the daily samples collected during the spraying season at any of the locations and during any given year contained 2,4-D, with butyl esters being found most frequently. The daily 24-hr mean atmospheric concentrations of 2,4-D ranged from 0.01 to 1.22 mug/m3, 0.01 to 13.50 mug/m3, and 0.05 to 0.59 mug/m3 for the iso-propyl, mixed butyl and iso-octyl esters, respectively. Even when the samples were analysed for the total 2,4-D content, i.e. from 1973 onwards, the maximum level of the total acid reached only 23.14 mug/m3. In any given year and at any of the sampling sites, about 30% of the samples contained less than 0.01 mug/m3 of 2,4-D. In another 40% of the samples, the levels of 2,4-D ranged from 0.01 to 0.099 mug/m3. Only about 30% of the samples contained 2,4-D concentrations higher than 0.1 mug/m3, with only 10% or less exceeding 1 mug/m3. None of the samples, obtained with the high volume particulate sampler, showed any detectable levels of 2,4-D, indicating little or no transport of 2,4-D adsorbed on dust particles or as crystals of amine salts.

  14. Quantitative filter forensics for indoor particle sampling.

    PubMed

    Haaland, D; Siegel, J A

    2017-03-01

    Filter forensics is a promising indoor air investigation technique involving the analysis of dust which has collected on filters in central forced-air heating, ventilation, and air conditioning (HVAC) or portable systems to determine the presence of indoor particle-bound contaminants. In this study, we summarize past filter forensics research to explore what it reveals about the sampling technique and the indoor environment. There are 60 investigations in the literature that have used this sampling technique for a variety of biotic and abiotic contaminants. Many studies identified differences between contaminant concentrations in different buildings using this technique. Based on this literature review, we identified a lack of quantification as a gap in the past literature. Accordingly, we propose an approach to quantitatively link contaminants extracted from HVAC filter dust to time-averaged integrated air concentrations. This quantitative filter forensics approach has great potential to measure indoor air concentrations of a wide variety of particle-bound contaminants. Future studies directly comparing quantitative filter forensics to alternative sampling techniques are required to fully assess this approach, but analysis of past research suggests the enormous possibility of this approach. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Air sampling to assess potential generation of aerosolized viable bacteria during flow cytometric analysis of unfixed bacterial suspensions

    PubMed Central

    Carson, Christine F; Inglis, Timothy JJ

    2018-01-01

    This study investigated aerosolized viable bacteria in a university research laboratory during operation of an acoustic-assisted flow cytometer for antimicrobial susceptibility testing by sampling room air before, during and after flow cytometer use. The aim was to assess the risk associated with use of an acoustic-assisted flow cytometer analyzing unfixed bacterial suspensions. Air sampling in a nearby clinical laboratory was conducted during the same period to provide context for the existing background of microorganisms that would be detected in the air. The three species of bacteria undergoing analysis by flow cytometer in the research laboratory were Klebsiella pneumoniae, Burkholderia thailandensis and Streptococcus pneumoniae. None of these was detected from multiple 1000 L air samples acquired in the research laboratory environment. The main cultured bacteria in both locations were skin commensal and environmental bacteria, presumed to have been disturbed or dispersed in laboratory air by personnel movements during routine laboratory activities. The concentrations of bacteria detected in research laboratory air samples were reduced after interventional cleaning measures were introduced and were lower than those in the diagnostic clinical microbiology laboratory. We conclude that our flow cytometric analyses of unfixed suspensions of K. pneumoniae, B. thailandensis and S. pneumoniae do not pose a risk to cytometer operators or other personnel in the laboratory but caution against extrapolation of our results to other bacteria and/or different flow cytometric experimental procedures. PMID:29608197

  16. Day and night variation in chemical composition and toxicological responses of size segregated urban air PM samples in a high air pollution situation

    NASA Astrophysics Data System (ADS)

    Jalava, P. I.; Wang, Q.; Kuuspalo, K.; Ruusunen, J.; Hao, L.; Fang, D.; Väisänen, O.; Ruuskanen, A.; Sippula, O.; Happo, M. S.; Uski, O.; Kasurinen, S.; Torvela, T.; Koponen, H.; Lehtinen, K. E. J.; Komppula, M.; Gu, C.; Jokiniemi, J.; Hirvonen, M.-R.

    2015-11-01

    Urban air particulate pollution is a known cause for adverse human health effects worldwide. China has encountered air quality problems in recent years due to rapid industrialization. Toxicological effects induced by particulate air pollution vary with particle sizes and season. However, it is not known how distinctively different photochemical activity and different emission sources during the day and the night affect the chemical composition of the PM size ranges and subsequently how it is reflected to the toxicological properties of the PM exposures. The particulate matter (PM) samples were collected in four different size ranges (PM10-2.5; PM2.5-1; PM1-0.2 and PM0.2) with a high volume cascade impactor. The PM samples were extracted with methanol, dried and thereafter used in the chemical and toxicological analyses. RAW264.7 macrophages were exposed to the particulate samples in four different doses for 24 h. Cytotoxicity, inflammatory parameters, cell cycle and genotoxicity were measured after exposure of the cells to particulate samples. Particles were characterized for their chemical composition, including ions, element and PAH compounds, and transmission electron microscopy (TEM) was used to take images of the PM samples. Chemical composition and the induced toxicological responses of the size segregated PM samples showed considerable size dependent differences as well as day to night variation. The PM10-2.5 and the PM0.2 samples had the highest inflammatory potency among the size ranges. Instead, almost all the PM samples were equally cytotoxic and only minor differences were seen in genotoxicity and cell cycle effects. Overall, the PM0.2 samples had the highest toxic potential among the different size ranges in many parameters. PAH compounds in the samples and were generally more abundant during the night than the day, indicating possible photo-oxidation of the PAH compounds due to solar radiation. This was reflected to different toxicity in the PM

  17. Marine Technician's Handbook, Instructions for Taking Air Samples on Board Ship: Carbon Dioxide Project.

    ERIC Educational Resources Information Center

    Keeling, Charles D.

    This booklet is one of a series intended to provide explicit instructions for the collection of oceanographic data and samples at sea. The methods and procedures described have been used by the Scripps Institution of Oceanography and found reliable and up-to-date. Instructions are given for taking air samples on board ship to determine the…

  18. Active AirCore Sampling: Constraining Point Sources of Methane and Other Gases with Fixed Wing Unmanned Aerial Systems

    NASA Astrophysics Data System (ADS)

    Bent, J. D.; Sweeney, C.; Tans, P. P.; Newberger, T.; Higgs, J. A.; Wolter, S.

    2017-12-01

    Accurate estimates of point source gas emissions are essential for reconciling top-down and bottom-up greenhouse gas measurements, but sampling such sources is challenging. Remote sensing methods are limited by resolution and cloud cover; aircraft methods are limited by air traffic control clearances, and the need to properly determine boundary layer height. A new sampling approach leverages the ability of unmanned aerial systems (UAS) to measure all the way to the surface near the source of emissions, improving sample resolution, and reducing the need to characterize a wide downstream swath, or measure to the full height of the planetary boundary layer (PBL). The "Active-AirCore" sampler, currently under development, will fly on a fixed wing UAS in Class G airspace, spiraling from the surface to 1200 ft AGL around point sources such as leaking oil wells to measure methane, carbon dioxide and carbon monoxide. The sampler collects a 100-meter long sample "core" of air in an 1/8" passivated stainless steel tube. This "core" is run on a high-precision instrument shortly after the UAS is recovered. Sample values are mapped to a specific geographic location by cross-referencing GPS and flow/pressure metadata, and fluxes are quantified by applying Gauss's theorem to the data, mapped onto the spatial "cylinder" circumscribed by the UAS. The AirCore-Active builds off the sampling ability and analytical approach of the related AirCore sampler, which profiles the atmosphere passively using a balloon launch platform, but will add an active pumping capability needed for near-surface horizontal sampling applications. Here, we show design elements, laboratory and field test results for methane, describe the overall goals of the mission, and discuss how the platform can be adapted, with minimal effort, to measure other gas species.

  19. Sampling, storage, and analysis of C2-C7 non-methane hydrocarbons from the US National Oceanic and Atmospheric Administration Cooperative Air Sampling Network glass flasks.

    PubMed

    Pollmann, Jan; Helmig, Detlev; Hueber, Jacques; Plass-Dülmer, Christian; Tans, Pieter

    2008-04-25

    An analytical technique was developed to analyze light non-methane hydrocarbons (NMHC), including ethane, propane, iso-butane, n-butane, iso-pentane, n-pentane, n-hexane, isoprene, benzene and toluene from whole air samples collected in 2.5l-glass flasks used by the National Oceanic and Atmospheric Administration, Earth System Research Laboratory, Global Monitoring Division (NOAA ESRL GMD, Boulder, CO, USA) Cooperative Air Sampling Network. This method relies on utilizing the remaining air in these flasks (which is at below-ambient pressure at this stage) after the completion of all routine greenhouse gas measurements from these samples. NMHC in sample aliquots extracted from the flasks were preconcentrated with a custom-made, cryogen-free inlet system and analyzed by gas chromatography (GC) with flame ionization detection (FID). C2-C7 NMHC, depending on their ambient air mixing ratios, could be measured with accuracy and repeatability errors of generally < or =10-20%. Larger deviations were found for ethene and propene. Hexane was systematically overestimated due to a chromatographic co-elution problem. Saturated NMHC showed less than 5% changes in their mixing ratios in glass flask samples that were stored for up to 1 year. In the same experiment ethene and propene increased at approximately 30% yr(-1). A series of blank experiments showed negligible contamination from the sampling process and from storage (<10 pptv yr(-1)) of samples in these glass flasks. Results from flask NMHC analyses were compared to in-situ NMHC measurements at the Global Atmospheric Watch station in Hohenpeissenberg, Germany. This 9-months side-by-side comparison showed good agreement between both methods. More than 94% of all data comparisons for C2-C5 alkanes, isoprene, benzene and toluene fell within the combined accuracy and precision objectives of the World Meteorological Organization Global Atmosphere Watch (WMO-GAW) for NMHC measurements.

  20. Irreversible sorption of trace concentrations of perfluorocarboxylic acids to fiber filters used for air sampling

    NASA Astrophysics Data System (ADS)

    Arp, Hans Peter H.; Goss, Kai-Uwe

    Due to the apparent environmental omnipresence of perfluorocarboxylic acids (PFAs), an increasing number of researchers are investigating their ambient particle- and gas-phase concentrations. Typically this is done using a high-volume air sampler equipped with Quartz Fiber Filters (QFFs) or Glass Fiber Filters (GFFs) to sample the particle-bound PFAs and downstream sorbents to sample the gas-phase PFAs. This study reports that at trace, ambient concentrations gas-phase PFAs sorb to QFFs and GFFs irreversibly and hardly pass through these filters to the downstream sorbents. As a consequence, it is not possible to distinguish between particle- and gas-phase concentrations, or to distinguish concentrations on different particle size fractions, unless precautions are taken. Failure to take such precautions could have already caused reported data to be misinterpreted. Here it is also reported that deactivating QFFs and GFFs with a silylating agent renders them suitable for sampling PFAs. Based on the presented study, a series of recommendations for air-sampling PFAs are provided.

  1. Comparison of Air Impaction and Electrostatic Dust Collector Sampling Methods to Assess Airborne Fungal Contamination in Public Buildings.

    PubMed

    Normand, Anne-Cécile; Ranque, Stéphane; Cassagne, Carole; Gaudart, Jean; Sallah, Kankoé; Charpin, Denis-André; Piarroux, Renaud

    2016-03-01

    Many ailments can be linked to exposure to indoor airborne fungus. However, obtaining a precise measurement of airborne fungal levels is complicated partly due to indoor air fluctuations and non-standardized techniques. Electrostatic dust collector (EDC) sampling devices have been used to measure a wide range of airborne analytes, including endotoxins, allergens, β-glucans, and microbial DNA in various indoor environments. In contrast, viable mold contamination has only been assessed in highly contaminated environments such as farms and archive buildings. This study aimed to assess the use of EDCs, compared with repeated air-impactor measurements, to assess airborne viable fungal flora in moderately contaminated indoor environments. Indoor airborne fungal flora was cultured from EDCs and daily air-impaction samples collected in an office building and a daycare center. The quantitative fungal measurements obtained using a single EDC significantly correlated with the cumulative measurement of nine daily air impactions. Both methods enabled the assessment of fungal exposure, although a few differences were observed between the detected fungal species and the relative quantity of each species. EDCs were also used over a 32-month period to monitor indoor airborne fungal flora in a hospital office building, which enabled us to assess the impact of outdoor events (e.g. ground excavations) on the fungal flora levels on the indoor environment. In conclusion, EDC-based measurements provided a relatively accurate profile of the viable airborne flora present during a sampling period. In particular, EDCs provided a more representative assessment of fungal levels compared with single air-impactor sampling. The EDC technique is also simpler than performing repetitive air-impaction measures over the course of several consecutive days. EDC is a versatile tool for collecting airborne samples and was efficient for measuring mold levels in indoor environments. © The Author 2015

  2. Atmospheric CO2 Records from Sites in the Main Geophysical Observatory Air Sampling Network (1983 - 1993)

    DOE Data Explorer

    Brounshtein, A. M. [Main Geophysical Observatory, St. Petersburg, Russia; Shaskov, A. A. [Main Geophysical Observatory, St. Petersburg, Russia; Paramonova, N. N. [Main Geophysical Observatory, St. Petersburg, Russia; Privalov, V. I. [Main Geophysical Observatory, St. Petersburg, Russia; Starodubtsev, Y. A. [Main Geophysical Observatory, St. Petersburg, Russia

    1997-01-01

    Air samples were collected from five sites in the Main Geophysical Observatory air sampling network to monitor the atmospheric CO2 from 1983 - 1993. Airwas collected generally four times per month in pairs of 1.5-L stainless steel electropolished flasks with one greaseless stainless steel stopcock. Sampling was performed by opening the stopcock of the flasks, which have been evacuated at the central laboratory at the Main Geophysical Observatory (MGO). The air was not dried during sample collection. Attempts were made to obtain samples when the wind speed was >5 m/s and the wind direction corresponded to the predetermined "clean air" sector. The period of record at Bering Island is too short to identify any long-term trends in atmospheric CO2 concentrations; however, the yearly mean atmospheric CO2 concentration at Bering Island rose from approximately 346 parts per million by volume (ppmv) in 1986 to 362.6 ppmv in 1993. Measurements from this station are considered indicative of maritime air masses. The period of record at Kotelny Island is too short to identify any long-term trends in atmospheric CO2 concentrations; however, the yearly mean atmospheric CO2 concentration at Kotelny Island rose from 356.08 parts per million by volume (ppmv) in 1988 to 358.8 ppmv in 1993. Because Kotelny Island is the northernmost Russian sampling site, measurements from this site serve as a useful comparison to other northern sites (e.g., Alert, Northwest Territories). In late 1989, air sampling began at the Russian site of Kyzylcha, located in the Republic of Uzbekistan. Unfortunately, the desert site at Kyzylcha has been out of operation since mid-1991 due to financial difficulties in Russia. The annual mean value of 359.02 parts per million by volume (ppmv) for 1990, the lone full year of operation, is higher than measurements from other monitoring programs at this latitude [e.g., Niwot Ridge (354.7 ppmv in 1990) and Tae-ahn Peninsula]. Station "C," an open ocean site, in the

  3. Comparison of Passive and Active Air Sampling (PAAS) Methods for PCBs – A Pilot Study in New York City Schools

    EPA Science Inventory

    PCBs were used extensively in school building materials (caulk and lighting fixture ballasts) during the approximate period of 1950-1978. Most of the schools built nationwide during this period have not had indoor air sampling conducted for PCBs. Passive air sampling holds promi...

  4. Mathematical estimation of the level of microbial contamination on spacecraft surfaces by volumetric air sampling

    NASA Technical Reports Server (NTRS)

    Oxborrow, G. S.; Roark, A. L.; Fields, N. D.; Puleo, J. R.

    1974-01-01

    Microbiological sampling methods presently used for enumeration of microorganisms on spacecraft surfaces require contact with easily damaged components. Estimation of viable particles on surfaces using air sampling methods in conjunction with a mathematical model would be desirable. Parameters necessary for the mathematical model are the effect of angled surfaces on viable particle collection and the number of viable cells per viable particle. Deposition of viable particles on angled surfaces closely followed a cosine function, and the number of viable cells per viable particle was consistent with a Poisson distribution. Other parameters considered by the mathematical model included deposition rate and fractional removal per unit time. A close nonlinear correlation between volumetric air sampling and airborne fallout on surfaces was established with all fallout data points falling within the 95% confidence limits as determined by the mathematical model.

  5. Potential contamination of shipboard air samples by diffusive emissions of PCBs and other organic pollutants: implications and solutions.

    PubMed

    Lohmann, Rainer; Jaward, Foday M; Durham, Louise; Barber, Jonathan L; Ockenden, Wendy; Jones, Kevin C; Bruhn, Regina; Lakaschus, Soenke; Dachs, Jordi; Booij, Kees

    2004-07-15

    Air samples were taken onboard the RRS Bransfield on an Atlantic cruise from the United Kingdom to Halley, Antarctica, from October to December 1998, with the aim of establishing PCB oceanic background air concentrations and assessing their latitudinal distribution. Great care was taken to minimize pre- and post-collection contamination of the samples, which was validated through stringent QA/QC procedures. However, there is evidence that onboard contamination of the air samples occurred,following insidious, diffusive emissions on the ship. Other data (for PCBs and other persistent organic pollutants (POPs)) and examples of shipboard contamination are presented. The implications of these findings for past and future studies of global POPs distribution are discussed. Recommendations are made to help critically appraise and minimize the problems of insidious/diffusive shipboard contamination.

  6. Development of a wireless air pollution sensor package for aerial-sampling of emissions

    EPA Science Inventory

    A new sensor system for mobile and aerial emission sampling was developed for open area pollutant sources, such as prescribed forest burns. The sensor system, termed “Kolibri”, consists of multiple low-cost air quality sensors measuring CO2, CO, samplers for particulate matter wi...

  7. Influence of relative humidity on VOC concentrations in indoor air.

    PubMed

    Markowicz, Pawel; Larsson, Lennart

    2015-04-01

    Volatile organic compounds (VOCs) may be emitted from surfaces indoors leading to compromised air quality. This study scrutinized the influence of relative humidity (RH) on VOC concentrations in a building that had been subjected to water damage. While air samplings in a damp room at low RH (21-22%) only revealed minor amounts of 2-ethylhexanol (3 μg/m(3)) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB, 8 μg/m(3)), measurements performed after a rapid increase of RH (to 58-75%) revealed an increase in VOC concentrations which was 3-fold for 2-ethylhexanol and 2-fold for TXIB. Similar VOC emission patterns were found in laboratory analyses of moisture-affected and laboratory-contaminated building materials. This study demonstrates the importance of monitoring RH when sampling indoor air for VOCs in order to avoid misleading conclusions from the analytical results.

  8. Evaluation of solid sorbents for the determination of fenhexamid, metalaxyl-M, pyrimethanil, malathion and myclobutanil residues in air samples: application to monitoring malathion and fenhexamid dissipation in greenhouse air using C-18 or Supelpak-2 for sampling.

    PubMed

    Tsiropoulos, Nikolaos G; Bakeas, Evangelos B; Raptis, Vasilios; Batistatou, Stavroula S

    2006-07-28

    A methodology is described for greenhouse air analysis by sampling fenhexamid, pyrimethanil, malathion, metalaxyl-M and myclobutanil in solid sorbents. Pesticides were determined by gas chromatography with NP Detector. The trapping efficiency of XAD-2, XAD-4, Supelpak-2, Florisil and C-18 at different sampling conditions (rate, time and air humidity) and pesticides concentration levels has been evaluated. No breakthrough was observed in the range of concentration studied (0.10-75 microg of each pesticide). In almost all the cases good stability results were obtained. Personal pumps have been used with selected sorbents (Supelpak-2 and C-18) in order to sample malathion and fenhexamid in air of experimental greenhouse after their application in a tomato crop. The dissipation process of the analytes in various time periods after application has been studied. Malathion concentrations varied between 20.1 microg m(-3) just after application and 1.06 microg m(-3) 3 days later. Fenhexamid concentrations, determined by high performance liquid chromatography with UV detection, fall rapidly; after 12 h post-application being below 0.50 microg m(-3).

  9. Atmospheric Carbon Dioxide Mixing Ratios from the NOAA CMDL Carbon Cycle Cooperative Global Air Sampling Network (2009)

    DOE Data Explorer

    Conway, Thomas [NOAA Climate Monitoring and Diagnostics Laboratory, Boulder, CO (USA); Tans, Pieter [NOAA Climate Monitoring and Diagnostics Laboratory, Boulder, CO (USA)

    2009-01-01

    The National Oceanic and Atmospheric Administration's Climate Monitoring and Diagnostics Laboratory (NOAA/CMDL) has measured CO2 in air samples collected weekly at a global network of sites since the late 1960s. Atmospheric CO2 mixing ratios reported in these files were measured by a nondispersive infrared absorption technique in air samples collected in glass flasks. All CMDL flask samples are measured relative to standards traceable to the World Meteorological Organization (WMO) CO2 mole fraction scale. These measurements constitute the most geographically extensive, carefully calibrated, internally consistent atmospheric CO2 data set available and are essential for studies aimed at better understanding the global carbon cycle budget.

  10. Concentration and characteristics of depleted uranium in water, air and biological samples collected in Serbia and Montenegro.

    PubMed

    Jia, Guogang; Belli, Maria; Sansone, Umberto; Rosamilia, Silvia; Gaudino, Stefania

    2005-09-01

    During the Balkan conflicts, in 1995 and 1999, depleted uranium (DU) rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Serbia and Montenegro, radiological surveys of DU in water, air and biological samples were carried out over the period 27 October-5 November 2001. The uranium isotopic concentrations in biological samples collected in Serbia and Montenegro, mainly lichens and barks, were found to be in the range of 0.67-704 Bqkg(-1) for (238)U, 0.48-93.9 Bqkg(-1) for (234)U and 0.02-12.2 Bqkg(-1) for (235)U, showing uranium levels to be higher than in the samples collected at the control sites. Moreover, (236)U was detectable in some of the samples. The isotopic ratios of (234)U/(238)U showed DU to be detectable in many biological samples at all examined sites, especially in Montenegro, indicating widespread ground-surface DU contamination, albeit at very low level. The uranium isotopic concentrations in air obtained from the air filter samples collected in Serbia and Montenegro were found to be in the range of 1.99-42.1 microBqm(-3) for (238)U, 0.96-38.0 microBqm(-3) for (234)U, and 0.05-1.83 microBqm(-3) for (235)U, being in the typical range of natural uranium values. Thus said, most of the air samples are DU positive, this fact agreeing well with the widespread DU contamination detected in the biological samples. The uranium concentrations in water samples collected in Serbia and Montenegro were found to be in the range of 0.40-21.9 mBql(-1) for (238)U, 0.27-28.1 mBql(-1) for (234)U, and 0.01-0.88 mBql(-1) for (235)U, these values being much lower than those in mineral water found in central Italy and below the WHO guideline for drinking water. From a radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated

  11. Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    MULKEY, C.H.

    1999-07-06

    This document describes the results of the data quality objective (DQO) process undertaken to define data needs for state and federal requirements associated with toxic, hazardous, and/or radiological air emissions under the jurisdiction of the River Protection Project (RPP). Hereafter, this document is referred to as the Air DQO. The primary drivers for characterization under this DQO are the regulatory requirements pursuant to Washington State regulations, that may require sampling and analysis. The federal regulations concerning air emissions are incorporated into the Washington State regulations. Data needs exist for nonradioactive and radioactive waste constituents and characteristics as identified through themore » DQO process described in this document. The purpose is to identify current data needs for complying with regulatory drivers for the measurement of air emissions from RPP facilities in support of air permitting. These drivers include best management practices; similar analyses may have more than one regulatory driver. This document should not be used for determining overall compliance with regulations because the regulations are in constant change, and this document may not reflect the latest regulatory requirements. Regulatory requirements are also expected to change as various permits are issued. Data needs require samples for both radionuclides and nonradionuclide analytes of air emissions from tanks and stored waste containers. The collection of data is to support environmental permitting and compliance, not for health and safety issues. This document does not address health or safety regulations or requirements (those of the Occupational Safety and Health Administration or the National Institute of Occupational Safety and Health) or continuous emission monitoring systems. This DQO is applicable to all equipment, facilities, and operations under the jurisdiction of RPP that emit or have the potential to emit regulated air pollutants.« less

  12. A realistic in vitro exposure revealed seasonal differences in (pro-)inflammatory effects from ambient air in Fribourg, Switzerland.

    PubMed

    Bisig, Christoph; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

    2018-01-01

    Ambient air pollutant levels vary widely in space and time, therefore thorough local evaluation of possible effects is needed. In vitro approaches using lung cell cultures grown at the air-liquid interface and directly exposed to ambient air can offer a reliable addition to animal experimentations and epidemiological studies. To evaluate the adverse effects of ambient air in summer and winter a multi-cellular lung model (16HBE14o-, macrophages, and dendritic cells) was exposed in a mobile cell exposure system. Cells were exposed on up to three consecutive days each 12 h to ambient air from Fribourg, Switzerland, during summer and winter seasons. Higher particle number, particulate matter mass, and nitrogen oxide levels were observed in winter ambient air compared to summer. Good cell viability was seen in cells exposed to summer air and short-term winter air, but cells exposed three days to winter air were compromised. Exposure of summer ambient air revealed no significant upregulation of oxidative stress or pro-inflammatory genes. On the opposite, the winter ambient air exposure led to an increased oxidative stress after two exposure days, and an increase in three assessed pro-inflammatory genes already after 12 h of exposure. We found that even with a short exposure time of 12 h adverse effects in vitro were observed only during exposure to winter but not summer ambient air. With this work we have demonstrated that our simple, fast, and cost-effective approach can be used to assess (adverse) effects of ambient air.

  13. 3D Air Quality and the Clean Air Interstate Rule: Lagrangian Sampling of CMAQ Model Results to Aid Regional Accountability Metrics

    NASA Technical Reports Server (NTRS)

    Fairlie, T. D.; Szykman, Jim; Pierce, Robert B.; Gilliland, A. B.; Engel-Cox, Jill; Weber, Stephanie; Kittaka, Chieko; Al-Saadi, Jassim A.; Scheffe, Rich; Dimmick, Fred; hide

    2008-01-01

    The Clean Air Interstate Rule (CAIR) is expected to reduce transport of air pollutants (e.g. fine sulfate particles) in nonattainment areas in the Eastern United States. CAIR highlights the need for an integrated air quality observational and modeling system to understand sulfate as it moves in multiple dimensions, both spatially and temporally. Here, we demonstrate how results from an air quality model can be combined with a 3d monitoring network to provide decision makers with a tool to help quantify the impact of CAIR reductions in SO2 emissions on regional transport contributions to sulfate concentrations at surface monitors in the Baltimore, MD area, and help improve decision making for strategic implementation plans (SIPs). We sample results from the Community Multiscale Air Quality (CMAQ) model using ensemble back trajectories computed with the NASA Langley Research Center trajectory model to provide Lagrangian time series and vertical profile information, that can be compared with NASA satellite (MODIS), EPA surface, and lidar measurements. Results are used to assess the regional transport contribution to surface SO4 measurements in the Baltimore MSA, and to characterize the dominant source regions for low, medium, and high SO4 episodes.

  14. Whole air canister sampling coupled with preconcentration GC/MS analysis of part-per-trillion levels of trimethylsilanol in semiconductor cleanroom air.

    PubMed

    Herrington, Jason S

    2013-08-20

    The costly damage airborne trimethylsilanol (TMS) exacts on optics in the semiconductor industry has resulted in the demand for accurate and reliable methods for measuring TMS at trace levels (i.e., parts per trillion, volume per volume of air [ppt(v)] [~ng/m(3)]). In this study I developed a whole air canister-based approach for field sampling trimethylsilanol in air, as well as a preconcentration gas chromatography/mass spectrometry laboratory method for analysis. The results demonstrate clean canister blanks (0.06 ppt(v) [0.24 ng/m(3)], which is below the detection limit), excellent linearity (a calibration relative response factor relative standard deviation [RSD] of 9.8%) over a wide dynamic mass range (1-100 ppt(v)), recovery/accuracy of 93%, a low selected ion monitoring method detection limit of 0.12 ppt(v) (0.48 ng/m(3)), replicate precision of 6.8% RSD, and stability (84% recovery) out to four days of storage at room temperature. Samples collected at two silicon wafer fabrication facilities ranged from 10.0 to 9120 ppt(v) TMS and appear to be associated with the use of hexamethyldisilazane priming agent. This method will enable semiconductor cleanroom managers to monitor and control for trace levels of trimethylsilanol.

  15. Estimating Sampling Biases and Measurement Uncertainties of AIRS-AMSU-A Temperature and Water Vapor Observations Using MERRA Reanalysis

    NASA Technical Reports Server (NTRS)

    Hearty, Thomas J.; Savtchenko, Andrey K.; Tian, Baijun; Fetzer, Eric; Yung, Yuk L.; Theobald, Michael; Vollmer, Bruce; Fishbein, Evan; Won, Young-In

    2014-01-01

    We use MERRA (Modern Era Retrospective-Analysis for Research Applications) temperature and water vapor data to estimate the sampling biases of climatologies derived from the AIRS/AMSU-A (Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit-A) suite of instruments. We separate the total sampling bias into temporal and instrumental components. The temporal component is caused by the AIRS/AMSU-A orbit and swath that are not able to sample all of time and space. The instrumental component is caused by scenes that prevent successful retrievals. The temporal sampling biases are generally smaller than the instrumental sampling biases except in regions with large diurnal variations, such as the boundary layer, where the temporal sampling biases of temperature can be +/- 2 K and water vapor can be 10% wet. The instrumental sampling biases are the main contributor to the total sampling biases and are mainly caused by clouds. They are up to 2 K cold and greater than 30% dry over mid-latitude storm tracks and tropical deep convective cloudy regions and up to 20% wet over stratus regions. However, other factors such as surface emissivity and temperature can also influence the instrumental sampling bias over deserts where the biases can be up to 1 K cold and 10% wet. Some instrumental sampling biases can vary seasonally and/or diurnally. We also estimate the combined measurement uncertainties of temperature and water vapor from AIRS/AMSU-A and MERRA by comparing similarly sampled climatologies from both data sets. The measurement differences are often larger than the sampling biases and have longitudinal variations.

  16. CTEPP STANDARD OPERATING PROCEDURE FOR COLLECTION OF FIXED SITE INDOOR AND OUTDOOR AIR SAMPLES FOR PERSISTENT ORGANIC POLLUTANTS (SOP-2.12)

    EPA Science Inventory

    This SOP describes the procedures to set up, calibrate, initiate and terminate air sampling for persistent organic pollutants. This method is used to sample air, indoors and outdoors, at homes and at day care centers over a 48-hr period.

  17. Fogwater Chemistry and Air Quality in the Texas-Louisiana Gulf Coast Corridor

    NASA Astrophysics Data System (ADS)

    Kommalapati, R. R.; Raja, S.; Ravikrishna, R.; Murugesan, K.; Collett, J. L.; Valsaraj, K.

    2007-05-01

    The presence of fog water in polluted atmosphere can influence atmospheric chemistry and air quality. The study of interactions between fog water and atmospheric gases and aerosols are very important in understanding the atmospheric fate of the pollutants. In this Study several air samples and fogwater samples were collected in the heavily industrialized area of Gulf Coast corridor( Houston, TX and Baton Rouge, LA). A total of 32 fogwater samples were collected, comprising of nine fog events in Baton Rouge (Nov 2004 to Feb 2005) and two fog events in Houston (Feb, 2006), during the fog sampling campaigns. These samples were analyzed for pH, total and dissolved carbon, major inorganic ions, organic acids, and aromatics, aldehydes, VOCs, and linear alkanes organic compounds. Fogwater samples collected in Houston show clear influence of marine and anthropogenic environment, while Baton Rouge samples reveal a relatively less polluted environment. Also, a time series observation of air samples indicated that fog event at the monitoring site impacted the air concentrations of the pollutants. This is attributed to presence of surface active organic matter in fog water.

  18. Soyuz 22 Return Samples: Assessment of Air Quality Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Jams, John T.

    2010-01-01

    Three mini-grab sample containers (m-GSCs) were returned aboard Soyuz 22 because of concerns that new air pollutants were present in the air and these were getting into the water recovery system. The Total Organic Carbon Analyzer had been giving increasing readings of total organic carbon (TOC) in the potable water, and it was postulated that an increased load into the system was responsible. The toxicological assessment of 3 m-GSCs from the ISS is shown in Table 1. The recoveries of the 3 standards (as listed above) from the GSCs averaged 103, 95 and 76%, respectively. Recovery from formaldehyde control badges were 90 and 91%.

  19. Air permeability and trapped-air content in two soils

    USGS Publications Warehouse

    Stonestrom, David A.; Rubin, Jacob

    1989-01-01

    To improve understanding of hysteretic air permeability relations, a need exists for data on the water content dependence of air permeability, matric pressure, and air trapping (especially for wetting-drying cycles). To obtain these data, a special instrument was designed. The instrument is a combination of a gas permeameter (for air permeability determination), a suction plate apparatus (for retentivity curve determination), and an air pycnometer (for trapped-air-volume determination). This design allowed values of air permeability, matric pressure, and air trapping to be codetermined, i.e., determined at the same values of water content using the same sample and the same inflow-outflow boundaries. Such data were obtained for two nonswelling soils. The validity of the air permeability determinations was repeatedly confirmed by rigorous tests of Darcy's law. During initial drying from complete water saturation, supplementary measurements were made to assess the magnitude of gas slip. The extended Darcy equation accurately described the measured flux gradient relations for each condition of absolute gas pressure tested. Air permeability functions exhibited zero-permeability regions at high water contents as well as an abruptly appearing hysteresis at low water contents. Measurements in the zero-permeability regions revealed that the total amount of air in general exceeded the amount of trapped air. This indicates that the medium' s air space is partitioned into three measurable domains: through-flowing air, locally accessible air (i.e., air accessible from only one flow boundary), and trapped air. During repeated wetting and drying, the disappearance and reappearance of air permeability coincided closely with the reappearance and disappearance, respectively, of trapped air. The observed relation between critical features of the air permeability functions and those of the air-trapping functions suggest that water-based blockages play a significant role in the

  20. An analytical method for trifluoroacetic Acid in water and air samples using headspace gas chromatographic determination of the methyl ester.

    PubMed

    Zehavi, D; Seiber, J N

    1996-10-01

    An analytical method has been developed for the determination of trace levels of trifluoroacetic acid (TFA), an atmospheric breakdown product of several of the hydrofluorocarbon (HFC) and hydrochlorofluorocarbon (HCFC) replacements for the chlorofluorocarbon (CFC) refrigerants, in water and air. TFA is derivatized to the volatile methyl trifluoroacetate (MTFA) and determined by automated headspace gas chromatography (HSGC) with electron-capture detection or manual HSGC using GC/MS in the selected ion monitoring (SIM) mode. The method is based on the reaction of an aqueous sample containing TFA with dimethyl sulfate (DMS) in concentrated sulfuric acid in a sealed headspace vial under conditions favoring distribution of MTFA to the vapor phase. Water samples are prepared by evaporative concentration, during which TFA is retained as the anion, followed by extraction with diethyl ether of the acidified sample and then back-extraction of TFA (as the anion) in aqueous bicarbonate solution. The extraction step is required for samples with a relatively high background of other salts and organic materials. Air samples are collected in sodium bicarbonate-glycerin-coated glass denuder tubes and prepared by rinsing the denuder contents with water to form an aqueous sample for derivatization and analysis. Recoveries of TFA from spiked water, with and without evaporative concentration, and from spiked air were quantitative, with estimated detection limits of 10 ng/mL (unconcentrated) and 25 pg/mL (concentrated 250 mL:1 mL) for water and 1 ng/m(3) (72 h at 5 L/min) for air. Several environmental air, fogwater, rainwater, and surface water samples were successfully analyzed; many showed the presence of TFA.

  1. Glyphosate–rich air samples induce IL–33, TSLP and generate IL–13 dependent airway inflammation

    PubMed Central

    Kumar, Sudhir; Khodoun, Marat; Kettleson, Eric M.; McKnight, Christopher; Reponen, Tiina; Grinshpun, Sergey A.; Adhikari, Atin

    2014-01-01

    Several low weight molecules have often been implicated in the induction of occupational asthma. Glyphosate, a small molecule herbicide, is widely used in the world. There is a controversy regarding a role of glyphosate in developing asthma and rhinitis among farmers, the mechanism of which is unexplored. The aim of this study was to explore the mechanisms of glyphosate induced pulmonary pathology by utilizing murine models and real environmental samples. C57BL/6, TLR4−/−, and IL-13−/− mice inhaled extracts of glyphosate-rich air samples collected on farms during spraying of herbicides or inhaled different doses of glyphosate and ovalbumin. The cellular response, humoral response, and lung function of exposed mice were evaluated. Exposure to glyphosate-rich air samples as well as glyphosate alone to the lungs increased: eosinophil and neutrophil counts, mast cell degranulation, and production of IL-33, TSLP, IL-13, and IL-5. In contrast, in vivo systemic IL-4 production was not increased. Co-administration of ovalbumin with glyphosate did not substantially change the inflammatory immune response. However, IL-13-deficiency resulted in diminished inflammatory response but did not have a significant effect on airway resistance upon methacholine challenge after 7 or 21 days of glyphosate exposure. Glyphosate-rich farm air samples as well as glyphosate alone were found to induce pulmonary IL-13-dependent inflammation and promote Th2 type cytokines, but not IL-4 for glyphosate alone. This study, for the first time, provides evidence for the mechanism of glyphosate-induced occupational lung disease. PMID:25172162

  2. Role of air sampling in investigation of an outbreak of legionnaires' disease associated with exposure to aerosols from an evaporative condenser.

    PubMed

    Breiman, R F; Cozen, W; Fields, B S; Mastro, T D; Carr, S J; Spika, J S; Mascola, L

    1990-06-01

    Epidemiologic studies have suggested that legionnaires' disease can be transmitted to susceptible hosts by contaminated aerosolized water from cooling towers and evaporative condensers; however, epidemic strains of Legionella have not been isolated by air sampling at such sites during epidemiologic investigations. An outbreak of legionnaires' disease occurred at a retirement hotel; Legionella pneumophila serogroup 1 was isolated from an evaporative condenser and from potable water. A case-control study showed that the only significant exposure risk was in area A. L. pneumophila serogroup 1 was isolated during air sampling near the evaporative condenser exhaust site, the air conditioning intake vent, and an air vent in area A, but not in shower stalls. Monoclonal antibody subtype patterns of L. pneumophila serogroup 1 isolates from patients matched those from the evaporative condenser but not from shower water. Air sampling and monoclonal antibody subtyping results support epidemiologic evidence that the evaporative condenser was the source of this outbreak.

  3. Determination of air-loop volume and radon partition coefficient for measuring radon in water sample.

    PubMed

    Lee, Kil Yong; Burnett, William C

    A simple method for the direct determination of the air-loop volume in a RAD7 system as well as the radon partition coefficient was developed allowing for an accurate measurement of the radon activity in any type of water. The air-loop volume may be measured directly using an external radon source and an empty bottle with a precisely measured volume. The partition coefficient and activity of radon in the water sample may then be determined via the RAD7 using the determined air-loop volume. Activity ratios instead of absolute activities were used to measure the air-loop volume and the radon partition coefficient. In order to verify this approach, we measured the radon partition coefficient in deionized water in the temperature range of 10-30 °C and compared the values to those calculated from the well-known Weigel equation. The results were within 5 % variance throughout the temperature range. We also applied the approach for measurement of the radon partition coefficient in synthetic saline water (0-75 ppt salinity) as well as tap water. The radon activity of the tap water sample was determined by this method as well as the standard RAD-H 2 O and BigBottle RAD-H 2 O. The results have shown good agreement between this method and the standard methods.

  4. Soyuz 23 Return Samples: Assessment of Air Quality Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    James, John T.

    2011-01-01

    Six mini-grab sample containers (m-GSCs) were returned aboard Soyuz 23 because of concerns that new air pollutants had been present in the air and these were getting into the water recovery system. The Total Organic Carbon Analyzer had been giving increasing readings of total organic carbon (TOC) in the potable water, and it was postulated that an increased load into the system was responsible. The TOC began to decline in late October, 2010. The toxicological assessment of 6 m-GSCs from the ISS is shown in Table 1. The recoveries of 13C-acetone, fluorobenzene, and chlorobenzene from the GSCs averaged 73, 82, and 59%, respectively. We are working to understand the sub-optimal recovery of chlorobenzene.

  5. A new analysis system for whole air sampling: description and results from 2013 SENEX

    NASA Astrophysics Data System (ADS)

    Lerner, B. M.; Gilman, J.; Dumas, M.; Hughes, D.; Jaksich, A.; Hatch, C. D.; Graus, M.; Warneke, C.; Apel, E. C.; Hornbrook, R. S.; Holloway, J. S.; De Gouw, J. A.

    2014-12-01

    Accurate measurement of volatile organic compounds (VOCs) in the troposphere is critical for the understanding of emissions and physical and chemical processes that can impact both air quality and climate. Airborne VOC measurements have proven especially challenging due to the requirement of both high sensitivity (pptv) and short sample collection times (≤15 s) to maximize spatial resolution and sampling frequency for targeted plume analysis. The use of stainless steel canisters to collect whole air samples (WAS) for post-flight analysis has been pioneered by the groups of D. Blake and E. Atlas [Blake et al., 1992; Atlas et al., 1993]. For the 2013 Southeast Nexus Study (SENEX), the NOAA ESRL CSD laboratory undertook WAS measurements for the first time. This required the construction of three new, highly-automated, and field-portable instruments designed to sample, analyze, and clean the canisters for re-use. Analysis was performed with a new custom-built gas chromatograph-mass spectrometer system. The instrument pre-concentrates analyte cryostatically into two parallel traps by means of a Stirling engine, a novel technique which obviates the need for liquid nitrogen to reach trapping temperatures of -175C. Here we present an evaluation of the retrieval of target VOC species from WAS canisters. We discuss the effects of humidity and sample age on the analyte, particularly upon C8+ alkane and aromatic species and biogenic species. Finally, we present results from several research flights during SENEX that targeted emissions from oil/natural gas production.

  6. Solid sorbent air sampling and analytical procedure for methyl-, dimethyl-, ethyl-, and diethylamine

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Elskamp, C.J.; Schultz, G.R.

    1986-01-01

    A sampling and analytical procedure for methyl-, dimethyl-, ethyl-, and diethylamine was developed in order to avoid problems typically encountered in the sampling and analysis of low molecular weight aliphatic amines. Samples are collected with adsorbent tubes containing Amberlite XAD-7 resin coated with the derivatizing reagent, NBD chloride (7-chloro-4-nitrobenzo-2-oxa-1,3-diazole). Analysis is performed by high performance liquid chromatography with the use of a fluorescence and/or UV/visible detector. All four amines can be monitored simultaneously, and neither collection nor storage is affected by humidity. Samples are stable at room temperature for at least two weeks. The methodology has been tested for eachmore » of the four amines at sample loadings equivalent to air concentration ranges of 0.5 to 30 ppm for a sample volume of 10 liters. The method shows promise for determining other airborne primary and secondary low molecular weight aliphatic amines.« less

  7. Breakthrough during air sampling with polyurethane foam: What do PUF 2/PUF 1 ratios mean?

    PubMed

    Bidleman, Terry F; Tysklind, Mats

    2018-02-01

    Frontal chromatography theory is applied to describe movement of gaseous semivolatile organic compounds (SVOCs) through a column of polyurethane foam (PUF). Collected mass fractions (F C ) are predicted for sample volume/breakthrough volume ratios (τ = V S /V B ) up to 6.0 and PUF bed theoretical plate numbers (N) from 2 to 16. The predictions assume constant air concentrations and temperatures. Extension of the calculations is done to relate the collection efficiency of a 2-PUF train (F C1+2 ) to the PUF 2/PUF 1 ratio. F C1+2 exceeds 0.9 for PUF 2/PUF 1 ≤ 0.5 and lengths of PUF commonly used in air samplers. As the PUF 2/PUF 1 ratio approaches unity, confidence in these predictions is limited by the analytical ability to distinguish residues on the two PUFs. Field data should not be arbitrarily discarded because some analytes broke through to the backup PUF trap. The fractional collection efficiencies can be used to estimate air concentrations from quantities retained on the PUF trap when sampling is not quantitative. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Methane mole fraction and δ13C above and below the trade wind inversion at Ascension Island in air sampled by aerial robotics

    NASA Astrophysics Data System (ADS)

    Brownlow, R.; Lowry, D.; Thomas, R. M.; Fisher, R. E.; France, J. L.; Cain, M.; Richardson, T. S.; Greatwood, C.; Freer, J.; Pyle, J. A.; MacKenzie, A. R.; Nisbet, E. G.

    2016-11-01

    Ascension Island is a remote South Atlantic equatorial site, ideal for monitoring tropical background CH4. In September 2014 and July 2015, octocopters were used to collect air samples in Tedlar bags from different heights above and below the well-defined Trade Wind Inversion (TWI), sampling a maximum altitude of 2700 m above mean sea level. Sampling captured both remote air in the marine boundary layer below the TWI and also air masses above the TWI that had been lofted by convective systems in the African tropics. Air above the TWI was characterized by higher CH4, but no distinct shift in δ13C was observed compared to the air below. Back trajectories indicate that lofted CH4 emissions from Southern Hemisphere Africa have bulk δ13CCH4 signatures similar to background, suggesting mixed emissions from wetlands, agriculture, and biomass burning. The campaigns illustrate the usefulness of unmanned aerial system sampling and Ascension's value for atmospheric measurement in an understudied region.

  9. Air and Surface Sampling Method for Assessing Exposures to Quaternary Ammonium Compounds Using Liquid Chromatography Tandem Mass Spectrometry.

    PubMed

    LeBouf, Ryan F; Virji, Mohammed Abbas; Ranpara, Anand; Stefaniak, Aleksandr B

    2017-07-01

    This method was designed for sampling select quaternary ammonium (quat) compounds in air or on surfaces followed by analysis using ultraperformance liquid chromatography tandem mass spectrometry. Target quats were benzethonium chloride, didecyldimethylammonium bromide, benzyldimethyldodecylammonium chloride, benzyldimethyltetradecylammonium chloride, and benzyldimethylhexadecylammonium chloride. For air sampling, polytetrafluoroethylene (PTFE) filters are recommended for 15-min to 24-hour sampling. For surface sampling, Pro-wipe® 880 (PW) media was chosen. Samples were extracted in 60:40 acetonitrile:0.1% formic acid for 1 hour on an orbital shaker. Method detection limits range from 0.3 to 2 ng/ml depending on media and analyte. Matrix effects of media are minimized through the use of multiple reaction monitoring versus selected ion recording. Upper confidence limits on accuracy meet the National Institute for Occupational Safety and Health 25% criterion for PTFE and PW media for all analytes. Using PTFE and PW analyzed with multiple reaction monitoring, the method quantifies levels among the different quats compounds with high precision (<10% relative standard deviation) and low bias (<11%). The method is sensitive enough with very low method detection limits to capture quats on air sampling filters with only a 15-min sample duration with a maximum assessed storage time of 103 days before sample extraction. This method will support future exposure assessment and quantitative epidemiologic studies to explore exposure-response relationships and establish levels of quats exposures associated with adverse health effects. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  10. Crossett Hydrogen Sulfide Air Sampling Report

    EPA Pesticide Factsheets

    This report summarizes the results of the EPA’s hydrogen sulfide air monitoring conducted along Georgia Pacific’s wastewater treatment system and in surrounding Crossett, AR, neighborhoods in 2017.

  11. Cast Stone Oxidation Front Evaluation: Preliminary Results For Samples Exposed To Moist Air

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Langton, C. A.; Almond, P. M.

    The rate of oxidation is important to the long-term performance of reducing salt waste forms because the solubility of some contaminants, e.g., technetium, is a function of oxidation state. TcO{sub 4}{sup -} in the salt solution is reduced to Tc(IV) and has been shown to react with ingredients in the waste form to precipitate low solubility sulfide and/or oxide phases. Upon exposure to oxygen, the compounds containing Tc(IV) oxidize to the pertechnetate ion, Tc(VII)O{sub 4}{sup -}, which is very soluble. Consequently the rate of technetium oxidation front advancement into a monolith and the technetium leaching profile as a function ofmore » depth from an exposed surface are important to waste form performance and ground water concentration predictions. An approach for measuring contaminant oxidation rate (effective contaminant specific oxidation rate) based on leaching of select contaminants of concern is described in this report. In addition, the relationship between reduction capacity and contaminant oxidation is addressed. Chromate (Cr(VI) was used as a non-radioactive surrogate for pertechnetate, Tc(VII), in Cast Stone samples prepared with 5 M Simulant. Cast Stone spiked with pertechnetate was also prepared and tested. Depth discrete subsamples spiked with Cr were cut from Cast Stone exposed to Savannah River Site (SRS) outdoor ambient temperature fluctuations and moist air. Depth discrete subsamples spiked with Tc-99 were cut from Cast Stone exposed to laboratory ambient temperature fluctuations and moist air. Similar conditions are expected to be encountered in the Cast Stone curing container. The leachability of Cr and Tc-99 and the reduction capacities, measured by the Angus-Glasser method, were determined for each subsample as a function of depth from the exposed surface. The results obtained to date were focused on continued method development and are preliminary and apply to the sample composition and curing / exposure conditions described in this

  12. Air, hand wipe, and surface wipe sampling for Bisphenol A (BPA) among workers in industries that manufacture and use BPA in the United States.

    PubMed

    Hines, Cynthia J; Jackson, Matthew V; Christianson, Annette L; Clark, John C; Arnold, James E; Pretty, Jack R; Deddens, James A

    2017-11-01

    For decades, bisphenol A (BPA) has been used in making polycarbonate, epoxy, and phenolic resins and certain investment casting waxes, yet published exposure data are lacking for U.S. manufacturing workers. In 2013-2014, BPA air and hand exposures were quantified for 78 workers at six U.S. companies making BPA or BPA-based products. Exposure measures included an inhalable-fraction personal air sample on each of two consecutive work days (n = 146), pre- and end-shift hand wipe samples on the second day (n = 74 each), and surface wipe samples (n = 88). Potential determinants of BPA air and end-shift hand exposures (after natural log transformation) were assessed in univariate and multiple regression mixed models. The geometric mean (GM) BPA air concentration was 4.0 µg/m 3 (maximum 920 µg/m 3 ). The end-shift GM BPA hand level (26 µg/sample) was 10-times higher than the pre-shift level (2.6 µg/sample). BPA air and hand exposures differed significantly by industry and job. BPA air concentrations and end-shift hand levels were highest in the BPA-filled wax manufacturing/reclaim industry (GM Air = 48 µg/m 3 , GM Hand-End = 130 µg/sample) and in the job of working with molten BPA-filled wax (GM Air = 43 µg/m 3 , GM Hand-End = 180 µg/sample), and lowest in the phenolic resins industry (GM Air = 0.85 µg/m 3 , GM Hand-End = 0.43 µg/sample) and in the job of flaking phenolic resins (GM AIR = 0.62 µg/m 3 , GM Hand-End = 0.38 µg/sample). Determinants of increased BPA air concentration were industry, handling BPA containers, spilling BPA, and spending ≥50% of the shift in production areas; increasing age was associated with lower air concentrations. BPA hand exposure determinants were influenced by high values for two workers; for all other workers, tasks involving contact with BPA-containing materials and spending ≥50% of the shift in production areas were associated with increased BPA hand levels. Surface wipe BPA levels were significantly lower in

  13. 6S Return Samples: Assessment of Air Quality in the International Space Station (ISS) Based on Solid Sorbent Air Sampler (SSAS) and Formaldehyde Monitoring Kit (FMK) Analyses

    NASA Technical Reports Server (NTRS)

    James, John T.

    2004-01-01

    The toxicological assessments of SSAS and FMK analytical results are reported. Analytical methods have not changed from earlier reports. Surrogate standard recoveries from the SSAS tubes were 66-76% for 13C-acetone, 85-96% for fluorobenzene, and 73-89% for chlorobenzene. Post-flight flows were far below pre-flight flows and an investigation of the problem revealed that the reduced flow was caused by a leak at the interface of the pump inlet tube and the pump head. This resulted in degradation of pump efficiency. Further investigation showed that the problem occurred before the SSAS was operated on orbit and that use of the post-flight flows yielded consistent and useful results. Recoveries from formaldehyde control badges were 86 to 104%. The two general criteria used to assess air quality are the total-non-methane-volatile organic hydrocarbons (NMVOCs) and the total T-value (minus the CO2 and formaldehyde contributions). The T values will not be reported for these data due to the flow anomaly. Control of atmospheric alcohols is important to the water recovery system engineers, hence total alcohols (including acetone) are also shown for each sample. Octafluoropropane (OFP) is not efficiently trapped by the sorbents used in the SSAS. Because formaldehyde is quantified from sorbent badges, its concentration is also listed separately. These five indices of air quality are summarized.

  14. Characterization and validation of sampling and analytical methods for mycotoxins in workplace air.

    PubMed

    Jargot, Danièle; Melin, Sandrine

    2013-03-01

    Mycotoxins are produced by certain plant or foodstuff moulds under growing, transport or storage conditions. They are toxic for humans and animals, some are carcinogenic. Methods to monitor occupational exposure to seven of the most frequently occurring airborne mycotoxins have been characterized and validated. Experimental aerosols have been generated from naturally contaminated particles for sampler evaluation. Air samples were collected on foam pads, using the CIP 10 personal aerosol sampler with its inhalable health-related aerosol fraction selector. The samples were subsequently solvent extracted from the sampling media, cleaned using immunoaffinity (IA) columns and analyzed by liquid chromatography with fluorescence detection. Ochratoxin A (OTA) or fumonisin and aflatoxin derivatives were detected and quantified. The quantification limits were 0.015 ng m(-3) OTA, 1 ng m(-3) fumonisins or 0.5 pg m(-3) aflatoxins, with a minimum dust concentration level of 1 mg m(-3) and a 4800 L air volume sampling. The methods were successfully applied to field measurements, which confirmed that workers could be exposed when handling contaminated materials. It was observed that airborne particles may be more contaminated than the bulk material itself. The validated methods have measuring ranges fully adapted to the concentrations found in the workplace. Their performance meets the general requirements laid down for chemical agent measurement procedures, with an expanded uncertainty less than 50% for most mycotoxins. The analytical uncertainty, comprised between 14 and 24%, was quite satisfactory given the low mycotoxin amounts, when compared to the food benchmarks. The methods are now user-friendly enough to be adopted for personal workplace sampling. They will later allow for mycotoxin occupational risk assessment, as only very few quantitative data have been available till now.

  15. Ultimate detectability of volatile organic compounds: how much further can we reduce their ambient air sample volumes for analysis?

    PubMed

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2012-10-02

    To understand the ultimately lowest detection range of volatile organic compounds (VOCs) in air, application of a high sensitivity analytical system was investigated by coupling thermal desorption (TD) technique with gas chromatography (GC) and time-of-flight (TOF) mass spectrometry (MS). The performance of the TD-GC/TOF MS system was evaluated using liquid standards of 19 target VOCs prepared in the range of 35 pg to 2.79 ng per μL. Studies were carried out using both total ion chromatogram (TIC) and extracted ion chromatogram (EIC) mode. EIC mode was used for calibration to reduce background and to improve signal-to-noise. The detectability of 19 target VOCs, if assessed in terms of method detection limit (MDL, per US EPA definition) and limit of detection (LOD), averaged 5.90 pg and 0.122 pg, respectively, with the mean coefficient of correlation (R(2)) of 0.9975. The minimum quantifiable mass of target analytes, when determined using real air samples by the TD-GC/TOF MS, is highly comparable to the detection limits determined experimentally by standard. In fact, volumes for the actual detection of the major aromatic VOCs like benzene, toluene, and xylene (BTX) in ambient air samples were as low as 1.0 mL in the 0.11-2.25 ppb range. It was thus possible to demonstrate that most target compounds including those in low abundance could be reliably quantified at concentrations down to 0.1 ppb at sample volumes of less than 10 mL. The unique sensitivity of this advanced analytical system can ultimately lead to a shift in field sampling strategy with smaller air sample volumes facilitating faster, simpler air sampling (e.g., use of gas syringes rather than the relative complexity of pumps or bags/canisters), with greatly reduced risk of analyte breakthrough and minimal interference, e.g., from atmospheric humidity. The improved detection limits offered by this system can also enhance accuracy and measurement precision.

  16. Ram-air sample collection device for a chemical warfare agent sensor

    DOEpatents

    Megerle, Clifford A.; Adkins, Douglas R.; Frye-Mason, Gregory C.

    2002-01-01

    In a surface acoustic wave sensor mounted within a body, the sensor having a surface acoustic wave array detector and a micro-fabricated sample preconcentrator exposed on a surface of the body, an apparatus for collecting air for the sensor, comprising a housing operatively arranged to mount atop the body, the housing including a multi-stage channel having an inlet and an outlet, the channel having a first stage having a first height and width proximate the inlet, a second stage having a second lower height and width proximate the micro-fabricated sample preconcentrator, a third stage having a still lower third height and width proximate the surface acoustic wave array detector, and a fourth stage having a fourth height and width proximate the outlet, where the fourth height and width are substantially the same as the first height and width.

  17. Assessment of Air Quality in the Shuttle and International Space Station (ISS) Based on Samples Returned by STS-104 at the Conclusion of 7A

    NASA Technical Reports Server (NTRS)

    James, John T.

    2001-01-01

    The toxicological assessment of air samples returned at the end of the STS-l04 (7 A) flight to the ISS is reported. ISS air samples were taken in June and July 2001 from the Service Module, FGB, and U.S. Laboratory using grab sample canisters (GSCs) and/or formaldehyde badges. Preflight and end-of-mission samples were obtained from Atlantis using GSCs. Solid sorbent air sampler (SSAS) samples were obtained from the ISS in April, June, and July. Analytical methods have not changed from earlier reports, and all quality control measures were met.

  18. [Air-conditioner disease. Results of an industrial medicine survey (author's transl)].

    PubMed

    Molina, C; Aiache, J M; Bedu, M; Menaut, P; Wahl, D; Brestowski, J; Grall, Y

    1982-07-03

    The results of a survey conducted in a company employing 1850 persons working in air-conditioned premises are reported. One hundred and five persons were examined, including 790 who mostly complained of respiratory disorders and 20 controls. Regular check-ups during the last two years have failed to reveal any serious disease. The most frequent complaints were rhinitis and tracheitis, especially among female employees. No alveolitis was observed. The finding of Bacillus subtilis in samples of ambient air and air-conditioner filters in conjunction with the presence of precipitating antibodies against crude extracts from these samples, suggested that the respiratory disorders might have been due to this microorganism. A multifactorial analysis demonstrated a statistically significant correlation between clinical symptoms and immunological disorders. The air-conditioner disease, therefore, may present as a benign condition.

  19. Contribution of Vegetation to the Microbial Composition of Nearby Outdoor Air

    PubMed Central

    Adams, Rachel I.

    2016-01-01

    ABSTRACT Given that epiphytic microbes are often found in large population sizes on plants, we tested the hypothesis that plants are quantitatively important local sources of airborne microorganisms. The abundance of microbial communities, determined by quantifying bacterial 16S RNA genes and the fungal internal transcribed spacer (ITS) region, in air collected directly above vegetation was 2- to 10-fold higher than that in air collected simultaneously in an adjacent nonvegetated area 50 m upwind. Nonmetric multidimensional scaling revealed that the composition of airborne bacteria in upwind air samples grouped separately from that of downwind air samples, while communities on plants and downwind air could not be distinguished. In contrast, fungal taxa in air samples were more similar to each other than to the fungal epiphytes. A source-tracking algorithm revealed that up to 50% of airborne bacteria in downwind air samples were presumably of local plant origin. The difference in the proportional abundances of a given operational taxonomic unit (OTU) between downwind and upwind air when regressed against the proportional representation of this OTU on the plant yielded a positive slope for both bacteria and fungi, indicating that those taxa that were most abundant on plants proportionally contributed more to downwind air. Epiphytic fungi were less of a determinant of the microbiological distinctiveness of downwind air and upwind air than epiphytic bacteria. Emigration of epiphytic bacteria and, to a lesser extent, fungi, from plants can thus influence the microbial composition of nearby air, a finding that has important implications for surrounding ecosystems, including the built environment into which outdoor air can penetrate. IMPORTANCE This paper addresses the poorly understood role of bacterial and fungal epiphytes, the inhabitants of the aboveground plant parts, in the composition of airborne microbes in outdoor air. It is widely held that epiphytes contribute

  20. Contribution of Vegetation to the Microbial Composition of Nearby Outdoor Air.

    PubMed

    Lymperopoulou, Despoina S; Adams, Rachel I; Lindow, Steven E

    2016-07-01

    Given that epiphytic microbes are often found in large population sizes on plants, we tested the hypothesis that plants are quantitatively important local sources of airborne microorganisms. The abundance of microbial communities, determined by quantifying bacterial 16S RNA genes and the fungal internal transcribed spacer (ITS) region, in air collected directly above vegetation was 2- to 10-fold higher than that in air collected simultaneously in an adjacent nonvegetated area 50 m upwind. Nonmetric multidimensional scaling revealed that the composition of airborne bacteria in upwind air samples grouped separately from that of downwind air samples, while communities on plants and downwind air could not be distinguished. In contrast, fungal taxa in air samples were more similar to each other than to the fungal epiphytes. A source-tracking algorithm revealed that up to 50% of airborne bacteria in downwind air samples were presumably of local plant origin. The difference in the proportional abundances of a given operational taxonomic unit (OTU) between downwind and upwind air when regressed against the proportional representation of this OTU on the plant yielded a positive slope for both bacteria and fungi, indicating that those taxa that were most abundant on plants proportionally contributed more to downwind air. Epiphytic fungi were less of a determinant of the microbiological distinctiveness of downwind air and upwind air than epiphytic bacteria. Emigration of epiphytic bacteria and, to a lesser extent, fungi, from plants can thus influence the microbial composition of nearby air, a finding that has important implications for surrounding ecosystems, including the built environment into which outdoor air can penetrate. This paper addresses the poorly understood role of bacterial and fungal epiphytes, the inhabitants of the aboveground plant parts, in the composition of airborne microbes in outdoor air. It is widely held that epiphytes contribute to atmospheric

  1. 24-HOUR DIFFUSIVE SAMPLING OF TOXIC VOCS IN AIR ONTO CARBOPACK X SOLID ADSORBENT FOLLOWED BY THERMAL DESORPTION/GC/MS ANALYSIS - LABORATORY STUDIES

    EPA Science Inventory

    Diffusive sampling of a mixture of 42 volatile organic compounds (VOCs) in humidified, purified air onto the solid adsorbent Carbopack X was evaluated under controlled laboratory conditions. The evaluation included variations in sample air temperature, relative humidity, and ozon...

  2. Alpha Air Sample Counting Efficiency Versus Dust Loading: Evaluation of a Large Data Set

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hogue, M. G.; Gause-Lott, S. M.; Owensby, B. N.

    Dust loading on air sample filters is known to cause a loss of efficiency for direct counting of alpha activity on the filters, but the amount of dust loading and the correction factor needed to account for attenuated alpha particles is difficult to assess. In this paper, correction factors are developed by statistical analysis of a large database of air sample results for a uranium and plutonium processing facility at the Savannah River Site. As is typically the case, dust-loading data is not directly available, but sample volume is found to be a reasonable proxy measure; the amount of dustmore » loading is inferred by a combination of the derived correction factors and a Monte Carlo model. The technique compares the distribution of activity ratios [beta/(beta + alpha)] by volume and applies a range of correction factors on the raw alpha count rate. The best-fit results with this method are compared with MCNP modeling of activity uniformly deposited in the dust and analytical laboratory results of digested filters. Finally, a linear fit is proposed to evenly-deposited alpha activity collected on filters with dust loading over a range of about 2 mg cm -2 to 1,000 mg cm -2.« less

  3. Alpha Air Sample Counting Efficiency Versus Dust Loading: Evaluation of a Large Data Set

    DOE PAGES

    Hogue, M. G.; Gause-Lott, S. M.; Owensby, B. N.; ...

    2018-03-03

    Dust loading on air sample filters is known to cause a loss of efficiency for direct counting of alpha activity on the filters, but the amount of dust loading and the correction factor needed to account for attenuated alpha particles is difficult to assess. In this paper, correction factors are developed by statistical analysis of a large database of air sample results for a uranium and plutonium processing facility at the Savannah River Site. As is typically the case, dust-loading data is not directly available, but sample volume is found to be a reasonable proxy measure; the amount of dustmore » loading is inferred by a combination of the derived correction factors and a Monte Carlo model. The technique compares the distribution of activity ratios [beta/(beta + alpha)] by volume and applies a range of correction factors on the raw alpha count rate. The best-fit results with this method are compared with MCNP modeling of activity uniformly deposited in the dust and analytical laboratory results of digested filters. Finally, a linear fit is proposed to evenly-deposited alpha activity collected on filters with dust loading over a range of about 2 mg cm -2 to 1,000 mg cm -2.« less

  4. SAMPLE DESIGN CONSIDERATIONS FOR INDOOR AIR EXPOSURE SURVEYS

    EPA Science Inventory

    Recent studies have shown that the traditional practice of monitoring outdoor (ambient) air quality leads to little information regarding the exposures of people in indoor surroundings. Consequently, EPA has begun a series of studies to determine the air pollution exposures peopl...

  5. The lung cancer breath signature: a comparative analysis of exhaled breath and air sampled from inside the lungs

    NASA Astrophysics Data System (ADS)

    Capuano, Rosamaria; Santonico, Marco; Pennazza, Giorgio; Ghezzi, Silvia; Martinelli, Eugenio; Roscioni, Claudio; Lucantoni, Gabriele; Galluccio, Giovanni; Paolesse, Roberto; di Natale, Corrado; D'Amico, Arnaldo

    2015-11-01

    Results collected in more than 20 years of studies suggest a relationship between the volatile organic compounds exhaled in breath and lung cancer. However, the origin of these compounds is still not completely elucidated. In spite of the simplistic vision that cancerous tissues in lungs directly emit the volatile metabolites into the airways, some papers point out that metabolites are collected by the blood and then exchanged at the air-blood interface in the lung. To shed light on this subject we performed an experiment collecting both the breath and the air inside both the lungs with a modified bronchoscopic probe. The samples were measured with a gas chromatography-mass spectrometer (GC-MS) and an electronic nose. We found that the diagnostic capability of the electronic nose does not depend on the presence of cancer in the sampled lung, reaching in both cases an above 90% correct classification rate between cancer and non-cancer samples. On the other hand, multivariate analysis of GC-MS achieved a correct classification rate between the two lungs of only 76%. GC-MS analysis of breath and air sampled from the lungs demonstrates a substantial preservation of the VOCs pattern from inside the lung to the exhaled breath.

  6. Comparison of Lichen, Conifer Needles, Passive Air Sampling Devices, and Snowpack as Passive Sampling Media to Measure Semi-Volatile Organic Compounds in Remote Atmospheres

    PubMed Central

    SCHRLAU, JILL E.; GEISER, LINDA; HAGEMAN, KIMBERLY J.; LANDERS, DIXON H.

    2011-01-01

    A wide range of semi-volatile organic compounds (SOCs), including pesticides and polycyclic aromatic hydrocarbons (PAHs), were measured in lichen, conifer needles, snowpack and XAD-based passive air sampling devices (PASDs) collected from 19 different U.S. national parks in order to compare the magnitude and mechanism of SOC accumulation in the different passive sampling media. Lichen accumulated the highest SOC concentrations, in part because of its long (and unknown) exposure period, while PASDs accumulated the lowest concentrations. However, only the PASD SOC concentrations can be used to calculate an average atmospheric gas-phase SOC concentration because the sampling rates are known and the media is uniform. Only the lichen and snowpack SOC accumulation profiles were statistically significantly correlated (r = 0.552, p-value <0.0001) because they both accumulate SOCs present in the atmospheric particle-phase. This suggests that needles and PASDs represent a different composition of the atmosphere than lichen and snowpack and that the interpretation of atmospheric SOC composition is dependent on the type of passive sampling media used. All four passive sampling media preferentially accumulated SOCs with relatively low air-water partition coefficients, while snowpack accumulated SOCs with higher log KOA values compared to the other media. Lichen accumulated more SOCs with log KOA > 10 relative to needles and showed a greater accumulation of particle-phase PAHs. PMID:22087860

  7. Cytotoxic and Inflammatory Potential of Air Samples from Occupational Settings with Exposure to Organic Dust

    PubMed Central

    Viegas, Susana; Caetano, Liliana Aranha; Korkalainen, Merja; Faria, Tiago; Pacífico, Cátia; Carolino, Elisabete; Quintal Gomes, Anita; Viegas, Carla

    2017-01-01

    Organic dust and related microbial exposures are the main inducers of several respiratory symptoms. Occupational exposure to organic dust is very common and has been reported in diverse settings. In vitro tests using relevant cell cultures can be very useful for characterizing the toxicity of complex mixtures present in the air of occupational environments such as organic dust. In this study, the cell viability and the inflammatory response, as measured by the production of pro-inflammatory cytokines tumor necrosis factor-α (TNFα) and interleukin-1 β (IL-1β), were determined in human macrophages derived from THP-1 monocytic cells. These cells were exposed to air samples from five occupational settings known to possess high levels of contamination of organic dust: poultry and swine feed industries, waste sorting, poultry production and slaughterhouses. Additionally, fungi and particle contamination of those settings was studied to better characterize the organic dust composition. All air samples collected from the assessed workplaces caused both cytotoxic and pro-inflammatory effects. The highest responses were observed in the feed industry, particularly in swine feed production. This study emphasizes the importance of measuring the organic dust/mixture effects in occupational settings and suggests that differences in the organic dust content may result in differences in health effects for exposed workers. PMID:29051440

  8. Reveal Salmonella 2.0 test for detection of Salmonella spp. in foods and environmental samples. Performance Tested Method 960801.

    PubMed

    Hoerner, Rebecca; Feldpausch, Jill; Gray, R Lucas; Curry, Stephanie; Islam, Zahidul; Goldy, Tim; Klein, Frank; Tadese, Theodros; Rice, Jennifer; Mozola, Mark

    2011-01-01

    Reveal Salmonella 2.0 is an improved version of the original Reveal Salmonella lateral flow immunoassay and is applicable to the detection of Salmonella enterica serogroups A-E in a variety of food and environmental samples. A Performance Tested Method validation study was conducted to compare performance of the Reveal 2.0 method with that of the U.S. Department of Agriculture-Food Safety and Inspection Service or U.S. Food and Drug Administration/Bacteriological Analytical Manual reference culture methods for detection of Salmonella spp. in chicken carcass rinse, raw ground turkey, raw ground beef, hot dogs, raw shrimp, a ready-to-eat meal product, dry pet food, ice cream, spinach, cantaloupe, peanut butter, stainless steel surface, and sprout irrigation water. In a total of 17 trials performed internally and four trials performed in an independent laboratory, there were no statistically significant differences in performance of the Reveal 2.0 and reference culture procedures as determined by Chi-square analysis, with the exception of one trial with stainless steel surface and one trial with sprout irrigation water where there were significantly more positive results by the Reveal 2.0 method. Considering all data generated in testing food samples using enrichment procedures specifically designed for the Reveal method, overall sensitivity of the Reveal method relative to the reference culture methods was 99%. In testing environmental samples, sensitivity of the Reveal method relative to the reference culture method was 164%. For select foods, use of the Reveal test in conjunction with reference method enrichment resulted in overall sensitivity of 92%. There were no unconfirmed positive results on uninoculated control samples in any trials for specificity of 100%. In inclusivity testing, 102 different Salmonella serovars belonging to serogroups A-E were tested and 99 were consistently positive in the Reveal test. In exclusivity testing of 33 strains of non

  9. High-throughput sequencing reveals unprecedented diversities of Aspergillus species in outdoor air.

    PubMed

    Lee, S; An, C; Xu, S; Lee, S; Yamamoto, N

    2016-09-01

    This study used the Illumina MiSeq to analyse compositions and diversities of Aspergillus species in outdoor air. The seasonal air samplings were performed at two locations in Seoul, South Korea. The results showed the relative abundances of all Aspergillus species combined ranging from 0·20 to 18% and from 0·19 to 21% based on the number of the internal transcribed spacer 1 (ITS1) and β-tubulin (BenA) gene sequences respectively. Aspergillus fumigatus was the most dominant species with the mean relative abundances of 1·2 and 5·5% based on the number of the ITS1 and BenA sequences respectively. A total of 29 Aspergillus species were detected and identified down to the species rank, among which nine species were known opportunistic pathogens. Remarkably, eight of the nine pathogenic species were detected by either one of the two markers, suggesting the need of using multiple markers and/or primer pairs when the assessments are made based on the high-throughput sequencing. Due to diversity of species within the genus Aspergillus, the high-throughput sequencing was useful to characterize their compositions and diversities in outdoor air, which are thought to be difficult to be accurately characterized by conventional culture and/or Sanger sequencing-based techniques. Aspergillus is a diverse genus of fungi with more than 300 species reported in literature. Aspergillus is important since some species are known allergens and opportunistic human pathogens. Traditionally, growth-dependent methods have been used to detect Aspergillus species in air. However, these methods are limited in the number of isolates that can be analysed for their identities, resulting in inaccurate characterizations of Aspergillus diversities. This study used the high-throughput sequencing to explore Aspergillus diversities in outdoor, which are thought to be difficult to be accurately characterized by traditional growth-dependent techniques. © 2016 The Society for Applied Microbiology.

  10. Characterization of two passive air samplers for per- and polyfluoroalkyl substances.

    PubMed

    Ahrens, Lutz; Harner, Tom; Shoeib, Mahiba; Koblizkova, Martina; Reiner, Eric J

    2013-12-17

    Two passive air sampler (PAS) media were characterized under field conditions for the measurement of per- and polyfluoroalkyl substances (PFASs) in the atmosphere. The PASs, consisting of polyurethane foam (PUF) and sorbent-impregnated PUF (SIP) disks, were deployed for over one year in parallel with high volume active air samplers (HV-AAS) and low volume active air samplers (LV-AAS). Samples were analyzed for perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkane sulfonic acids (PFSAs), fluorotelomer alcohols (FTOHs), fluorotelomer methacrylates (FTMACs), fluorotelomer acrylates (FTACs), perfluorooctane sulfonamides (FOSAs), and perfluorooctane sulfonamidoethanols (FOSEs). Sampling rates and the passive sampler medium (PSM)-air partition coefficient (KPSM-A) were calculated for individual PFASs. Sampling rates were similar for PFASs present in the gas phase and particle phase, and the linear sampling rate of 4 m(-3) d(-1) is recommended for calculating effective air sample volumes in the SIP-PAS and PUF-PAS for PFASs except for the FOSAs and FOSEs in the PUF-PAS. SIP disks showed very good performance for all tested PFASs while PUF disks were suitable only for the PFSAs and their precursors. Experiments evaluating the suitability of different isotopically labeled fluorinated depuration compounds (DCs) revealed that (13)C8-perfluorooctanoic acid (PFOA) was suitable for the calculation of site-specific sampling rates. Ambient temperature was the dominant factor influencing the seasonal trend of PFASs.

  11. US EPA Base Study Standard Operating Procedure for Sampling and Characterization of Viable and Non-Viable Bioaerosols in Indoor Air

    EPA Pesticide Factsheets

    The objective of the procedure is to collect a representative sample concentration of total airborne fungal spores (viable and non-viable) that may be present in indoor air and in the outdoor air supplied to the space tested.

  12. Development of sampling and analytical methods for concerted determination of commonly used chloroacetanilide, chlorotriazine, and 2,4-D herbicides in hand-wash, dermal-patch, and air samples.

    PubMed

    Tucker, S P; Reynolds, J M; Wickman, D C; Hines, C J; Perkins, J B

    2001-06-01

    Sampling and analytical methods were developed for commonly used chloroacetanilide, chlorotriazine, and 2,4-D herbicides in hand washes, on dermal patches, and in air. Eight herbicides selected for study were alachlor, atrazine, cyanazine, 2,4-dichlorophenoxyacetic acid (2,4-D), metolachlor, simazine, and two esters of 2,4-D, the 2-butoxyethyl ester (2,4-D, BE) and the 2-ethylhexyl ester (2,4-D, EH). The hand-wash method consisted of shaking the worker's hand in 150 mL of isopropanol in a polyethylene bag for 30 seconds. The dermal-patch method entailed attaching a 10-cm x 10-cm x 0.6-cm polyurethane foam (PUF) patch to the worker for exposure; recovery of the herbicides was achieved by extraction with 40 mL of isopropanol. The air method involved sampling with an OVS-2 tube (which contained an 11-mm quartz fiber filter and two beds of XAD-2 resin) and recovery with 2 mL of 10:90 methanol:methyl t-butyl ether. Analysis of each of the three sample types was performed by gas chromatography with an electron-capture detector. Diazomethane in solution was employed to convert 2,4-D as the free acid to the methyl ester in each of the three methods for ease of gas chromatography. Silicic acid was added to sample solutions to quench excess diazomethane. Limits of detection for all eight herbicides were matrix-dependent and, generally, less than 1 microgram per sample for each matrix. Sampling and analytical methods met NIOSH evaluation criteria for all herbicides in hand-wash samples, for seven herbicides in air samples (all herbicides except cyanazine), and for six herbicides in dermal-patch samples (all herbicides except cyanazine and 2,4-D). Speciation of 2,4-D esters and simultaneous determination of 2,4-D acid were possible without losses of the esters or of other herbicides (acetanilides and triazines) being determined.

  13. Atmospheric CO2 Records from Sites in the Atmospheric Environment Service Air Sampling Network (1975 and 1994)

    DOE Data Explorer

    Trivett, N. B.A. [Atmospheric Environment Service, Downsview, Ontario, Canada; Hudec, V. C. [Atmospheric Environment Service, Downsview, Ontario, Canada; Wong, C. S. [Marine Carbon Research Centre, Institute of Ocean Sciences, Sidney, British Columbia, Canada

    1997-01-01

    From the mid-1970s through the mid-1990s, air samples were collected for the purposes of monitoring atmospheric CO2 from four sites in the AES air sampling network. Air samples were collected approximately once per week, between 12:00 and 16:00 local time, in a pair of evacuated 2-L thick-wall borosilicate glass flasks. Samples were collected under preferred conditions of wind speed and direction (i.e., upwind of the main station and when winds are strong and steady). The flasks were evacuated to pressures of ~1 × 10-4 mbar or 0.01 Pa prior to being sent to the stations. The airwas not dried during sample collection. The flask data from Alert show an increase in the annual atmospheric CO2 concentration from 341.35 parts per million by volume (ppmv) in 1981 to 357.21 ppmv in 1991. For Cape St. James, Trivett and Higuchi (1989) reported that the mean annual rate of increase, obtained from the slope of a least-squares regression line through the annual averages, was 1.43 ppmv per year. In August 1992, the weather station at Cape St. James was automated; as a result, the flask sampling program was discontinued at this site. Estevan Point, on the West Coast of Vancouver Island, was chosen as a replacement station. Sampling at Estevan Point started in 1992; thus, the monthly and annual CO2record from Estevan Point is too short to show any long-term trends. The sampling site at Sable Island, off the coast of Nova Scotia, was established in 1975. The flask data from Sable Island show an increase in the annual atmospheric CO2 concentration from 334.49 parts per million by volume (ppmv) in 1977 (the first full year of data) to 356.02 ppmv in 1990. For Sable Island, Trivett and Higuchi (1989) reported that the mean annual rate of increase, obtained from the slope of a least-squares regression line through the annual averages, was 1.48 ppmv per year.

  14. Effect of Sampling Depth on Air-Sea CO2 Flux Estimates in River-Stratified Arctic Coastal Waters

    NASA Astrophysics Data System (ADS)

    Miller, L. A.; Papakyriakou, T. N.

    2015-12-01

    In summer-time Arctic coastal waters that are strongly influenced by river run-off, extreme stratification severely limits wind mixing, making it difficult to effectively sample the surface 'mixed layer', which can be as shallow as 1 m, from a ship. During two expeditions in southwestern Hudson Bay, off the Nelson, Hayes, and Churchill River estuaries, we confirmed that sampling depth has a strong impact on estimates of 'surface' pCO2 and calculated air-sea CO2 fluxes. We determined pCO2 in samples collected from 5 m, using a typical underway system on the ship's seawater supply; from the 'surface' rosette bottle, which was generally between 1 and 3 m; and using a niskin bottle deployed at 1 m and just below the surface from a small boat away from the ship. Our samples confirmed that the error in pCO2 derived from typical ship-board versus small-boat sampling at a single station could be nearly 90 μatm, leading to errors in the calculated air-sea CO2 flux of more than 0.1 mmol/(m2s). Attempting to extrapolate such fluxes over the 6,000,000 km2 area of the Arctic shelves would generate an error approaching a gigamol CO2/s. Averaging the station data over a cruise still resulted in an error of nearly 50% in the total flux estimate. Our results have implications not only for the design and execution of expedition-based sampling, but also for placement of in-situ sensors. Particularly in polar waters, sensors are usually deployed on moorings, well below the surface, to avoid damage and destruction from drifting ice. However, to obtain accurate information on air-sea fluxes in these areas, it is necessary to deploy sensors on ice-capable buoys that can position the sensors in true 'surface' waters.

  15. Air sampling methods to evaluate microbial contamination in operating theatres: results of a comparative study in an orthopaedics department.

    PubMed

    Napoli, C; Tafuri, S; Montenegro, L; Cassano, M; Notarnicola, A; Lattarulo, S; Montagna, M T; Moretti, B

    2012-02-01

    To evaluate the level of microbial contamination of air in operating theatres using active [i.e. surface air system (SAS)] and passive [i.e. index of microbial air contamination (IMA) and nitrocellulose membranes positioned near the wound] sampling systems. Sampling was performed between January 2010 and January 2011 in the operating theatre of the orthopaedics department in a university hospital in Southern Italy. During surgery, the mean bacterial loads recorded were 2232.9 colony-forming units (cfu)/m(2)/h with the IMA method, 123.2 cfu/m(3) with the SAS method and 2768.2 cfu/m(2)/h with the nitrocellulose membranes. Correlation was found between the results of the three methods. Staphylococcus aureus was detected in 12 of 60 operations (20%) with the membranes, five (8.3%) operations with the SAS method, and three operations (5%) with the IMA method. Use of nitrocellulose membranes placed near a wound is a valid method for measuring the microbial contamination of air. This method was more sensitive than the IMA method and was not subject to any calibration bias, unlike active air monitoring systems. Copyright © 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  16. PCDD/PCDF and dl-PCB in the ambient air of a tropical Andean city: passive and active sampling measurements near industrial and vehicular pollution sources.

    PubMed

    Cortés, J; González, C M; Morales, L; Abalos, M; Abad, E; Aristizábal, B H

    2014-09-01

    Concentration gradients were observed in gas and particulate phases of PCDD/F originating from industrial and vehicular sources in the densely populated tropical Andean city of Manizales, using passive and active air samplers. Preliminary results suggest greater concentrations of dl-PCB in the mostly gaseous fraction (using quarterly passive samplers) and greater concentrations of PCDD/F in the mostly particle fraction (using daily active samplers). Dioxin-like PCB predominance was associated with the semi-volatility property, which depends on ambient temperature. Slight variations of ambient temperature in Manizales during the sampling period (15°C-27°C) may have triggered higher concentrations in all passive samples. This was the first passive air sampling monitoring of PCDD/F conducted in an urban area of Colombia. Passive sampling revealed that PCDD/F in combination with dioxin-like PCB ranged from 16 WHO-TEQ2005/m(3) near industrial sources to 7 WHO-TEQ2005/m(3) in an intermediate zone-a reduction of 56% over 2.8 km. Active sampling of particulate phase PCDD/F and dl-PCB were analyzed in PM10 samples. PCDD/F combined with dl-PCB ranged from 46 WHO-TEQ2005/m(3) near vehicular sources to 8 WHO-TEQ2005/m(3) in the same intermediate zone, a reduction of 83% over 2.6 km. Toxic equivalent quantities in both PCDD/F and dl-PCB decreased toward an intermediate zone of the city. Variations in congener profiles were consistent with variations expected from nearby sources, such as a secondary metallurgy plant, areas of concentrated vehicular emissions and a municipal solid waste incinerator (MSWI). These variations in congener profile measurements of dioxins and dl-PCBs in passive and active samples can be partly explained by congener variations expected from the various sources. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Whole Air Sampling During NASA's March-April 1999 Pacific Exploratory Expedition (PEM-Tropics B)

    NASA Technical Reports Server (NTRS)

    Blake, Donald R.

    2001-01-01

    University of California, Irvine (UCI) collected more than 4500 samples whole air samples collected over the remote Pacific Ocean during NASA's Global Tropospheric Experiment (GTE) Pacific Exploratory Mission-Tropics B (PEM-Tropics B) in March and early April 1999. Approximately 140 samples during a typical 8-hour DC-8 flight, and 120 canisters for each 8-hour flight aboard the P-3B. These samples were obtained roughly every 3-7 min during horizontal flight legs and 1-3 min during vertical legs. The filled canisters were analyzed in the laboratory at UCI within ten days of collection. The mixing ratios of 58 trace gases comprising hydrocarbons, halocarbons, alkyl nitrates and DMS were reported (and archived) for each sample. Two identical analytical systems sharing the same standards were operated simultaneously around the clock to improve canister turn-around time and to keep our measurement precision optimal. This report presents a summary of the results for sample collected.

  18. Venturi Air-Jet Vacuum Ejector For Sampling Air

    NASA Technical Reports Server (NTRS)

    Hill, Gerald F.; Sachse, Glen W.; Burney, L. Garland; Wade, Larry O.

    1990-01-01

    Venturi air-jet vacuum ejector pump light in weight, requires no electrical power, does not contribute heat to aircraft, and provides high pumping speeds at moderate suctions. High-pressure motive gas required for this type of pump bled from compressor of aircraft engine with negligible effect on performance of engine. Used as source of vacuum for differential-absorption CO-measurement (DACOM), modified to achieve in situ measurements of CO at frequency response of 10 Hz. Provides improvement in spatial resolution and potentially leads to capability to measure turbulent flux of CO by use of eddy-correlation technique.

  19. An Improved Extraction and Analysis Technique for Determination of Carbon Monoxide Stable Isotopes and Mixing Ratios from Ice Core and Atmospheric Air Samples.

    NASA Astrophysics Data System (ADS)

    Place, P., Jr.; Petrenko, V. V.; Vimont, I.

    2017-12-01

    Carbon Monoxide (CO) is an important atmospheric trace gas that affects the oxidative capacity of the atmosphere and contributes indirectly to anthropogenic radiative forcing. Carbon monoxide stable isotopes can also serve as a tracer for variations in biomass burning, particularly in the preindustrial atmosphere. A good understanding of the past variations in CO mole fractions and isotopic composition can help improve the skill of chemical transport models and constrain biomass burning changes. Ice cores may preserve a record of past atmospheric CO for analysis and interpretation. To this end, a new extraction system has been developed for analysis of stable isotopes (δ13CO and δC18O) of atmospheric carbon monoxide from ice core and atmospheric air samples. This system has been designed to measure relatively small sample sizes (80 cc STP of air) to accommodate the limited availability of ice core samples. Trapped air is extracted from ice core samples via melting in a glass vacuum chamber. This air is expanded into a glass expansion loop and then compressed into the sample loop of a Reducing Gas Detector (Peak Laboratories, Peak Performer 1 RCP) for the CO mole fraction measurement. The remaining sample gas will be expelled from the melt vessel into a larger expansion loop via headspace compression for isotopic analysis. The headspace compression will be accomplished by introduction of clean degassed water into the bottom of the melt vessel. Isotopic analysis of the sample gas is done utilizing the Schütze Reagent to convert the carbon monoxide to carbon dioxide (CO2) which is then measured using continuous-flow isotope ratio mass spectrometry (Elementar Americas, IsoPrime 100). A series of cryogenic traps are used to purify the sample air, capture the converted sample CO2, and cryofocus the sample CO2 prior to injection.

  20. Determination of trichloroanisole and trichlorophenol in wineries' ambient air by passive sampling and thermal desorption-gas chromatography coupled to tandem mass spectrometry.

    PubMed

    Camino-Sánchez, F J; Bermúdez-Peinado, R; Zafra-Gómez, A; Ruíz-García, J; Vílchez-Quero, J L

    2015-02-06

    The present paper describes the calibration of selected passive samplers used in the quantitation of trichlorophenol and trichloroanisole in wineries' ambient air, by calculating the corresponding sampling rates. The method is based on passive sampling with sorbent tubes and involves thermal desorption-gas chromatography-triple quadrupole mass spectrometry analysis. Three commercially available sorbents were tested using sampling cartridges with a radial design instead of axial ones. The best results were found for Tenax TA™. Sampling rates (R-values) for the selected sorbents were determined. Passive sampling was also used for accurately determining the amount of compounds present in the air. Adequate correlation coefficients between the mass of the target analytes and exposure time were obtained. The proposed validated method is a useful tool for the early detection of trichloroanisole and its precursor trichlorophenol in wineries' ambient air while avoiding contamination of wine or winery facilities. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Direct measurements of sample heating by a laser-induced air plasma in pre-ablation spark dual-pulse laser-induced breakdown spectroscopy (LIBS).

    PubMed

    Register, Janna; Scaffidi, Jonathan; Angel, S Michael

    2012-08-01

    Direct measurements of temperature changes were made using small thermocouples (TC), placed near a laser-induced air plasma. Temperature changes up to ~500 °C were observed. From the measured temperature changes, estimates were made of the amount of heat absorbed per unit area. This allowed calculations to be made of the surface temperature, as a function of time, of a sample heated by the air plasma that is generated during orthogonal pre-ablation spark dual-pulse (DP) LIBS measurements. In separate experiments, single-pulse (SP) LIBS emission and sample ablation rate measurements were performed on nickel at sample temperatures ranging from room temperature to the maximum surface temperature that was calculated using the TC measurement results (500 °C). A small, but real sample temperature-dependent increase in both SP LIBS emission and the rate of sample ablation was found for nickel samples heated up to 500 °C. Comparison of DP LIBS emission enhancement values for bulk nickel samples at room temperature versus the enhanced SP LIBS emission and sample ablation rates observed as a function of increasing sample temperature suggests that sample heating by the laser-induced air plasma plays only a minor role in DP LIBS emission enhancement.

  2. A sensitive LC-MS/MS method for measurement of organophosphorus pesticides and their oxygen analogs in air sampling matrices.

    PubMed

    Armstrong, Jenna L; Dills, Russell L; Yu, Jianbo; Yost, Michael G; Fenske, Richard A

    2014-01-01

    A rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for determination of levels of the organophosphorus (OP) pesticides chlorpyrifos (CPF), azinphos methyl (AZM), and their oxygen analogs chlorpyrifos-oxon (CPF-O) and azinphos methyl-oxon (AZM-O) on common active air sampling matrices. XAD-2 resin and polyurethane foam (PUF) matrices were extracted with acetonitrile containing stable-isotope labeled internal standards (ISTD). Analysis was accomplished in Multiple Reaction Monitoring (MRM) mode, and analytes in unknown samples were identified by retention time (±0.1 min) and qualifier ratio (±30% absolute) as compared to the mean of calibrants. For all compounds, calibration linearity correlation coefficients were ≥0.996. Limits of detection (LOD) ranged from 0.15-1.1 ng/sample for CPF, CPF-O, AZM, and AZM-O on active sampling matrices. Spiked fortification recoveries were 78-113% from XAD-2 active air sampling tubes and 71-108% from PUF active air sampling tubes. Storage stability tests also yielded recoveries ranging from 74-94% after time periods ranging from 2-10 months. The results demonstrate that LC-MS/MS is a sensitive method for determining these compounds from two different matrices at the low concentrations that can result from spray drift and long range transport in non-target areas following agricultural applications. In an inter-laboratory comparison, the limit of quantification (LOQ) for LC-MS/MS was 100 times lower than a typical gas chromatography-mass spectrometry (GC-MS) method.

  3. NEW APPLICATION OF PASSIVE SAMPLING DEVICES FOR ASSESSMENT OF RESPIRATORY EXPOSURE TO PESTICIDES IN INDOOR AIR

    EPA Science Inventory

    The United States Environmental Protection Agency (EPA) has long maintained an interest in potential applications of passive sampling devices (PSDs) for estimating the concentrations of various pollutants in air. Typically PSDs were designed for the workplace monitoring of vola...

  4. Determination of biomass burning tracers in air samples by GC/MS

    NASA Astrophysics Data System (ADS)

    Janoszka, Katarzyna

    2018-01-01

    Levoglucosan (LG) as a main cellulose burning product at 300°C is a biomass burning tracer. LG characterize by relatively high molar mass and it is sorbed by particulate matter. In the study of air pollution monitoring LG is mainly analyzed in particulate matter, PM1 and PM2,5. The tracer create relatively high O-H…O bond and weaker C-H…O bond. Due to the hydrogen bond, LG dissolves very well in water. Analytical procedure of LG determination include: extraction, derivatization and analysis by gas chromatography coupled with mass spectrometry detector. In water samples levoglucosan is determined by liquid chromatography. The paper presents a methodology for particulate matter samples determination their analysis by gas chromatography coupled with a mass spectrometry detector. Determination of LG content in particulate matter was performed according to an analytical method based on simultaneous pyridine extraction and derivatization using N,O-bis (trimethylsilyl) trifluoroacetamide and trimethylchlorosilane mixture (BSTFA: TMCS, 99: 1).

  5. Stratospheric Trace Gas Composition Studies Utilizing in situ Cryogenic, Whole-Air Sampling Methods.

    DTIC Science & Technology

    1981-03-10

    C A FORSBERG, R V PIERI UNCLASSIFIED AFGL-TR-81-0071 NLEEEE..EEEEEEllllllu *Inaggol/numln ElhElhEEEEEEEI lllllllhhl , O \\ Stratospheric Trace Gas...GRANT NUJMBERr4; Charles A. Forsberg Robert V. Pieri , Capt., USAF Gerard A. Faucher B PERFORMING ORGANIZATION NAME AND ADDRESS IS. PROGRAM ELEMENT...launch site. 1 (Received for publication 10 March 1981) 1. Gallagher, C.(C., and Pieri , R. V. (1976) Cryogenic, Whole-Air Sampl1r and Program for

  6. Isokinetic air sampler

    DOEpatents

    Sehmel, George A.

    1979-01-01

    An isokinetic air sampler includes a filter, a holder for the filter, an air pump for drawing air through the filter at a fixed, predetermined rate, an inlet assembly for the sampler having an inlet opening therein of a size such that isokinetic air sampling is obtained at a particular wind speed, a closure for the inlet opening and means for simultaneously opening the closure and turning on the air pump when the wind speed is such that isokinetic air sampling is obtained. A system incorporating a plurality of such samplers provided with air pumps set to draw air through the filter at the same fixed, predetermined rate and having different inlet opening sizes for use at different wind speeds is included within the ambit of the present invention as is a method of sampling air to measure airborne concentrations of particulate pollutants as a function of wind speed.

  7. Analytical method validation for the determination of 2,3,3,3-tetrafluoropropene in air samples using gas chromatography with flame ionization detection.

    PubMed

    Mawn, Michael P; Kurtz, Kristine; Stahl, Deborah; Chalfant, Richard L; Koban, Mary E; Dawson, Barbara J

    2013-01-01

    A new low global warming refrigerant, 2,3,3,3-tetrafluoro propene, or HFO-1234yf, has been successfully evaluated for automotive air conditioning, and is also being evaluated for stationary refrigeration and air conditioning systems. Due to the advantageous environmental properties of HFO-1234yf versus HFC-134a, coupled with its similar physical properties and system performance, HFO-1234yf is also being evaluated to replace HFC-134a in refrigeration applications where neat HFC-134a is currently used. This study reports on the development and validation of a sampling and analytical method for the determination of HFO-1234yf in air. Different collection media were screened for desorption and simulated sampling efficiency with three-section (350/350/350 mg) Anasorb CSC showing the best results. Therefore, air samples were collected using two 3-section Anasorb CSC sorbent tubes in series at 0.02 L/min for up to 8 hr for sample volumes of up to 9.6 L. The sorbent tubes were extracted in methylene chloride, and analyzed by gas chromatography with flame ionization detection. The method was validated from 0.1× to 20× the target level of 0.5 ppm (2.3 mg/m(3)) for a 9.6 L air volume. Desorption efficiencies for HFO-1234yf were 88 to 109% for all replicates over the validation range with a mean overall recovery of 93%. Simulated sampling efficiencies ranged from 87 to 104% with a mean of 94%. No migration or breakthrough to the back tube was observed under the sampling conditions evaluated. HFO-1234yf samples showed acceptable storage stability on Anasorb CSC sorbent up to a period of 30 days when stored under ambient, refrigerated, or frozen temperature conditions.

  8. Air and surface contamination patterns of meticillin-resistant Staphylococcus aureus on eight acute hospital wards.

    PubMed

    Creamer, E; Shore, A C; Deasy, E C; Galvin, S; Dolan, A; Walley, N; McHugh, S; Fitzgerald-Hughes, D; Sullivan, D J; Cunney, R; Coleman, D C; Humphreys, H

    2014-03-01

    Meticillin-resistant Staphylococcus aureus (MRSA) can be recovered from hospital air and from environmental surfaces. This poses a potential risk of transmission to patients. To investigate associations between MRSA isolates recovered from air and environmental surfaces with those from patients when undertaking extensive patient and environmental sampling. This was a prospective observational study of patients and their environment in eight wards of a 700-bed tertiary care hospital during 2010 and 2011. Sampling of patients, air and surfaces was carried out on all ward bays, with more extended environmental sampling in ward high-dependency bays and at particular times of the day. The genetic relatedness of isolates was determined by DNA microarray profiling and spa typing. MRSA was recovered from 30/706 (4.3%) patients and from 19/132 (14.4%) air samples. On 9/132 (6.8%) occasions both patient and air samples yielded MRSA. In 32 high-dependency bays, MRSA was recovered from 12/161 (7.4%) patients, 8/32 (25%) air samples, and 21/644 (3.3%) environmental surface samples. On 10/132 (7.6%) occasions, MRSA was isolated from air in the absence of MRSA-positive patients. Patient demographic data combined with spa typing and DNA microarray profiling revealed four likely transmission clusters, where patient and environmental isolates were deemed to be very closely related. Air sampling yielded MRSA on frequent occasions, especially in high-dependency bays. Environmental and air sampling combined with patient demographic data, spa typing and DNA microarray profiling indicated the presence of clusters that were not otherwise apparent. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  9. Predator-guided sampling reveals biotic structure in the bathypelagic.

    PubMed

    Benoit-Bird, Kelly J; Southall, Brandon L; Moline, Mark A

    2016-02-24

    We targeted a habitat used differentially by deep-diving, air-breathing predators to empirically sample their prey's distributions off southern California. Fine-scale measurements of the spatial variability of potential prey animals from the surface to 1,200 m were obtained using conventional fisheries echosounders aboard a surface ship and uniquely integrated into a deep-diving autonomous vehicle. Significant spatial variability in the size, composition, total biomass, and spatial organization of biota was evident over all spatial scales examined and was consistent with the general distribution patterns of foraging Cuvier's beaked whales (Ziphius cavirostris) observed in separate studies. Striking differences found in prey characteristics between regions at depth, however, did not reflect differences observed in surface layers. These differences in deep pelagic structure horizontally and relative to surface structure, absent clear physical differences, change our long-held views of this habitat as uniform. The revelation that animals deep in the water column are so spatially heterogeneous at scales from 10 m to 50 km critically affects our understanding of the processes driving predator-prey interactions, energy transfer, biogeochemical cycling, and other ecological processes in the deep sea, and the connections between the productive surface mixed layer and the deep-water column. © 2016 The Author(s).

  10. Determination of polybrominated diphenyl ethers (PBDEs) in dust samples collected in air conditioning filters of different usage - method development.

    PubMed

    Śmiełowska, M; Zabiegała, B

    2018-06-19

    This study presents the results of studies aimed at the development of an analytical procedure for separation, identification, and determination of PBDEs compounds in dust samples collected from automotive cabin air filters and samples collected from filters installed as part of the air purification system in academic facilities. Ultrasound-assisted dispersive solid phase extraction (UA-dSPE) was found to perform better in terms of extract purification than the conventional SPE technique. GC-EIMS was used for final determination of analytes. The concentrations of PBDEs in car filters ranged from < LOD to 688 ng/g while from < LOD to 247 ng/g in dust from air conditioning filters. BDE-47 and BDE-100 were reported the dominating congeners. The estimated exposure to PBDEs via ingestion of dust from car filters varied from 0.00022 to 0.012 ng/day in toddlers and from 0.000036 to 0.0029 ng/day in adults; dust from air conditioning filters: from 0.017 to 0.25 ng/day in toddlers and from 0.0029 to 0.042 ng/day. In addition, an attempt was made at extracting PBDEs from a dust samples using the matrix solid-phase dispersion (MSPD) technique as a promising alternative to conventional SPE separations. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Passive air sampling using semipermeable membrane devices at different wind-speeds in situ calibrated by performance reference compounds.

    PubMed

    Söderström, Hanna S; Bergqvist, Per-Anders

    2004-09-15

    Semipermeable membrane devices (SPMDs) are passive samplers used to measure the vapor phase of organic pollutants in air. This study tested whether extremely high wind-speeds during a 21-day sampling increased the sampling rates of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), and whether the release of performance reference compounds (PRCs) was related to the uptakes at different wind-speeds. Five samplers were deployed in an indoor, unheated, and dark wind tunnel with different wind-speeds at each site (6-50 m s(-1)). In addition, one sampler was deployed outside the wind tunnel and one outside the building. To test whether a sampler, designed to reduce the wind-speeds, decreased the uptake and release rates, each sampler in the wind tunnel included two SPMDs positioned inside a protective device and one unprotected SPMD outside the device. The highest amounts of PAHs and PCBs were found in the SPMDs exposed to the assumed highest wind-speeds. Thus, the SPMD sampling rates increased with increasing wind-speeds, indicating that the uptake was largely controlled by the boundary layer at the membrane-air interface. The coefficient of variance (introduced by the 21-day sampling and the chemical analysis) for the air concentrations of three PAHs and three PCBs, calculated using the PRC data, was 28-46%. Thus, the PRCs had a high ability to predict site effects of wind and assess the actual sampling situation. Comparison between protected and unprotected SPMDs showed that the sampler design reduced the wind-speed inside the devices and thereby the uptake and release rates.

  12. BIBLE A whole-air sampling as a window on Asian biogeochemistry

    NASA Astrophysics Data System (ADS)

    Elliott, Scott; Blake, Donald R.; Blake, Nicola J.; Dubey, Manvendra K.; Rowland, F. Sherwood; Sive, Barkley C.; Smith, Felisa A.

    2003-02-01

    Asian trace gas and aerosol emissions into carbon, nitrogen, and other elemental cycles will figure prominently in near term Earth system evolution. Atmospheric hydrocarbon measurements resolve numerous chemical species and can be used to investigate sourcing for key geocarriers. A recent aircraft study of biomass burning and lightning (BIBLE A) explored the East Asian atmosphere and was unique in centering on the Indonesian archipelago. Samples of volatile organics taken over/between the islands of Japan, Saipan, Java, and Borneo are here examined as a guide to whole-air-based studies of future Asian biogeochemistry. The midlatitude onshore/offshore pulse and tropical convection strongly influence concentration distributions. As species of increasing molecular weight are considered, rural, combustion, and industrial source regimes emerge. Methane-rich inputs such as waste treatment and rice cultivation are evidenced in the geostrophic outflow. The Indonesian atmosphere is rich in biomass burning markers and also those of vehicular activity. Complexity of air chemistry in the archipelago is a direct reflection of diverse topography, land use, and local economies in a rapidly developing nation. Conspicuous in its absence is the fingerprint for liquefied petroleum gas leakage, but it can be expected to appear as demand for clean fossil fuels rises along with per capita incomes. Combustion tracers indicate high nitrogen mobilization rates, linking regional terrestrial geocycles with open marine ecosystems. Sea to air fluxes are superimposed on continental and marine backgrounds for the methyl halides. However, ocean hot spots are not coordinated and suggest an intricate subsurface kinetics. Levels of long-lived anthropogenic halocarbons attest to the success of international environmental treaties while reactive chlorine containing species track industrial air masses. The dozens of hydrocarbons resolvable by gas chromatographic methods will enable monitoring of

  13. Multistage open-tube trap for enrichment of part-per-trillion trace components of low-pressure (below 27-kPa) air samples

    NASA Technical Reports Server (NTRS)

    Ohara, D.; Vo, T.; Vedder, J. F.

    1985-01-01

    A multistage open-tube trap for cryogenic collection of trace components in low-pressure air samples is described. The open-tube design allows higher volumetric flow rates than densely packed glass-bead traps commonly reported and is suitable for air samples at pressures below 27 kPa with liquid nitrogen as the cryogen. Gas blends containing 200 to 2500 parts per trillion by volume each of ethane and ethene were sampled and hydrocarbons were enriched with 100 + or - 4 percent trap efficiency. The multistage design is more efficient than equal-length open-tube traps under the conditions of the measurements.

  14. Air, water, and surface bacterial contamination in a university-hospital autopsy room.

    PubMed

    Maujean, Géraldine; Malicier, Daniel; Fanton, Laurent

    2012-03-01

    Today, little is known about the bacteriological environment of the autopsy room and its potential interest for medico-legal practices. Seven hundred fifty microbiological samples were taken from surface (n = 660), air (n = 48), and water (n = 42) to evaluate it in a French University Forensic Department. Median bacterial counts were compared before and during autopsy for air samples, and before and after autopsy for surface samples, using Wilcoxon matched pairs signed ranks test. Bacterial identification relied on traditional phenotypic methods. Bacterial counts in the air were low before autopsy, increased significantly during procedure, and seemed more linked to the number of people in the room than to an important production of aerosol-containing bacteria. Despite cleaning, human fecal flora was omnipresent on surfaces, which revealed insufficient disinfection. Bacteriological sampling is an easy way to monitor cleaning practices in postmortem rooms, but chiefly a way to improve the reliability of medico-legal proofs of infectious deaths. © 2012 American Academy of Forensic Sciences.

  15. A sensitive LC-MS/MS method for measurement of organophosphorus pesticides and their oxygen analogs in air sampling matrices

    PubMed Central

    ARMSTRONG, JENNA L.; DILLS, RUSSELL L.; YU, JIANBO; YOST, MICHAEL G.; FENSKE, RICHARD A.

    2018-01-01

    A rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for determination of levels of the organophosphorus (OP) pesticides chlorpyrifos (CPF), azinphos methyl (AZM), and their oxygen analogs chlorpyrifos-oxon (CPF-O) and azinphos methyl-oxon (AZM-O) on common active air sampling matrices. XAD-2 resin and polyurethane foam (PUF) matrices were extracted with acetonitrile containing stable-isotope labeled internal standards (ISTD). Analysis was accomplished in Multiple Reaction Monitoring (MRM) mode, and analytes in unknown samples were identified by retention time (±0.1 min) and qualifier ratio (±30% absolute) as compared to the mean of calibrants. For all compounds, calibration linearity correlation coefficients were ≥0.996. Limits of detection (LOD) ranged from 0.15–1.1 ng/sample for CPF, CPF-O, AZM, and AZM-O on active sampling matrices. Spiked fortification recoveries were 78–113% from XAD-2 active air sampling tubes and 71–108% from PUF active air sampling tubes. Storage stability tests also yielded recoveries ranging from 74–94% after time periods ranging from 2–10 months. The results demonstrate that LC-MS/MS is a sensitive method for determining these compounds from two different matrices at the low concentrations that can result from spray drift and long range transport in non-target areas following agricultural applications. In an inter-laboratory comparison, the limit of quantification (LOQ) for LC-MS/MS was 100 times lower than a typical gas chromatography-mass spectrometry (GC-MS) method. PMID:24328542

  16. Intraoral Air Pressure of Alaryngeal Speakers during a No-Air Insufflation Maneuver.

    ERIC Educational Resources Information Center

    Gorham, Mary M.; And Others

    1996-01-01

    Intraoral air pressure was recorded during the production of consonant cognate pairs by 8 esophageal speakers (mean age 67 years) under 2 experimental conditions: after the insufflation of air and without air insufflation. Results revealed that peak intraoral air pressure magnitudes were significantly greater following the insufflation of air than…

  17. [Distribution Characteristics of Heavy Metals in Environmental Samples Around Electroplating Factories and the Health Risk Assessment].

    PubMed

    Guo, Peng-ran; Lei, Yong-qian; Zhou, Qiao-li; Wang, Chang; Pan, Jia-chuan

    2015-09-01

    This study aimed to investigate the pollution degree and human health risk of heavy metals in soil and air samples around electroplating factories. Soil, air and waste gas samples were collected to measure 8 heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in two electroplating factories, located in Baiyun district of Guangzhou city. Geoaccumulation index and USEPA Risk Assessment Guidance for Superfund (RAGS) were respectively carried out. Results showed that concentrations of Hg and Pb in waste gas and Cr in air samples were higher than limits of the corresponding quality standards, and concentrations of Cd, Hg and Zn in soil samples reached the moderate pollution level. The HQ and HI of exposure by heavy metals in air and soil samples were both lower than 1, indicating that there was no non-carcinogen risk. CRAs and CRCr in soil samples were beyond the maximum acceptable level of carcinogen risk (10(-4)), and the contribution rate of CRCr to TCR was over 81%. CRCr, CRNi and TCR in air samples were in range of 10(-6) - 10(-4), indicating there was possibly carcinogen risk but was acceptable risk. CR values for children were higher than adults in soils, but were higher for adults in air samples. Correlation analysis revealed that concentrations of heavy metals in soils were significantly correlated with these in waste gas samples, and PCA data showed pollution sources of Cd, Hg and Zn in soils were different from other metals.

  18. Measuring PM2.5, Ultrafine Particles, Nicotine Air and Wipe Samples Following the Use of Electronic Cigarettes.

    PubMed

    Melstrom, Paul; Koszowski, Bartosz; Thanner, Meridith Hill; Hoh, Eunha; King, Brian; Bunnell, Rebecca; McAfee, Tim

    2017-09-01

    Few studies have examined the extent of inhalation or dermal contact among bystanders following short-term, secondhand e-cigarette exposure. Measure PM2.5 (particles < 2.5 microns), UF (ultrafine particles < 100 nm), and nicotine in air and deposited on surfaces and clothing pre-/during/post- a short-term (2-hour) e-cigarette exposure. E-cigarettes were used ad libitum by three experienced users for 2 hours during two separate sessions (disposable e-cigarettes, then tank-style e-cigarettes, or "tanks") in a 1858 ft3 room. We recorded: uncorrected PM2.5 (using SidePak); UF (using P-Trak); air nicotine concentrations (using air samplers; SKC XAD-4 canisters); ambient air exchange rate (using an air capture hood). Wipe samples were taken by wiping 100 cm2 room surfaces pre- and post- both sessions, and clean cloth wipes were worn during the exposure and collected at the end. Uncorrected PM2.5 and UF were higher (p < .0001) during sessions than before or after. Median PM2.5 during exposure was higher using tanks (0.515 mg/m3) than disposables (0.035 mg/m3) (p < .0001). Median UF during exposure was higher using disposables (31 200 particles/cm3) than tanks (25 200 particles/cm3)(p < .0001). Median air nicotine levels were higher (p < .05) during both sessions (disposables = 0.697 ng/L, tanks = 1.833 ng/L) than before (disposables = 0.004 ng/L, tanks = 0.010 ng/L) or after (disposables = 0.115 ng/L, tanks = 0.147 ng/L). Median accumulation rates of nicotine on surface samples were 2.1 ng/100 cm2/h using disposables and 4.0 ng/100 cm2/h using tanks; for cloth samples, it was 44.4 ng/100 cm2/h using disposables and 69.6 ng/100 cm2/h using tanks (p < .01). Mean room ventilation rate was ~5 air changes per hour during both sessions. Short-term e-cigarette use can produce: elevated PM2.5; elevated UF; nicotine in the air; and accumulation of nicotine on surfaces and clothing. Short-term indoor e-cigarette use produced accumulation of nicotine on surfaces and clothing, which

  19. Methods for Integrated Air Sampling and DNA Analysis for Detection of Airborne Fungal Spores

    PubMed Central

    Williams, Roger H.; Ward, Elaine; McCartney, H. Alastair

    2001-01-01

    Integrated air sampling and PCR-based methods for detecting airborne fungal spores, using Penicillium roqueforti as a model fungus, are described. P. roqueforti spores were collected directly into Eppendorf tubes using a miniature cyclone-type air sampler. They were then suspended in 0.1% Nonidet P-40, and counted using microscopy. Serial dilutions of the spores were made. Three methods were used to produce DNA for PCR tests: adding untreated spores to PCRs, disrupting spores (fracturing of spore walls to release the contents) using Ballotini beads, and disrupting spores followed by DNA purification. Three P. roqueforti-specific assays were tested: single-step PCR, nested PCR, and PCR followed by Southern blotting and probing. Disrupting the spores was found to be essential for achieving maximum sensitivity of the assay. Adding untreated spores to the PCR did allow the detection of P. roqueforti, but this was never achieved when fewer than 1,000 spores were added to the PCR. By disrupting the spores, with or without subsequent DNA purification, it was possible to detect DNA from a single spore. When known quantities of P. roqueforti spores were added to air samples consisting of high concentrations of unidentified fungal spores, pollen, and dust, detection sensitivity was reduced. P. roqueforti DNA could not be detected using untreated or disrupted spore suspensions added to the PCRs. However, using purified DNA, it was possible to detect 10 P. roqueforti spores in a background of 4,500 other spores. For all DNA extraction methods, nested PCR was more sensitive than single-step PCR or PCR followed by Southern blotting. PMID:11375150

  20. Relative efficiencies of two air sampling methods and three culture conditions for the assessment of airborne culturable fungi in a poultry farmhouse in France.

    PubMed

    Nieguitsila, Adélaïde; Arné, Pascal; Durand, Benoît; Deville, Manjula; Benoît-Valiergue, Hélène; Chermette, René; Cottenot-Latouche, Sophie; Guillot, Jacques

    2011-02-01

    Fungal elements represent a significant part of the biological contaminants that could be detected in the air of animal facilities. The aim of this study was to assess the relative efficiencies of two air sampling methods and three culture conditions for the quantification of airborne culturable fungi in a poultry farmhouse in France. Air samples were collected every week throughout a 15-week period. Two devices were simultaneously used-a rotative cup air sampler (CIP 10-M, Arelco, France) and an air sampler based on filtration (AirPort MD8, Sartorius, Germany). Culture of airborne viable fungi was performed on malt extract agar (ME) and dichloran glycerol-18 (DG18) at 25 or 37°C. CIP 10-M and AirPort MD8 were shown to display comparable performances but significant differences were observed between culture conditions for Aspergillus spp. (p<0.01), Scopulariopsis spp. (p=0.02) and unidentified molds (p<0.01). Copyright © 2010 Elsevier Inc. All rights reserved.

  1. Sulfate and nitrate in Asian dust particles observed in desert, coastal and marine air

    NASA Astrophysics Data System (ADS)

    Zhang, D.; Wu, F.; Junji, C.

    2016-12-01

    Sulfate and nitrate in dust particles are believed to be two key species which can largely alter the physical and chemical properties of the particles in the atmosphere, in particular under humid conditions. Their occurrence in the particles has usually been considered to be the consequence of particles' aging during their long-distance travel in the air although they are present in some crustal minerals. Our observations at two deserts in China during dust episodes revealed that there were soil-derived sulfate and background-like nitrate in atmospheric dust samples. Sulfate in dust samples was proportional to samples' mass and comprised at steady mass percentages in differently sized samples. In contrast, nitrate concentration was approximately stable and independent from dust loading. Our observations at inland and coastal areas of China during dust episodes revealed that sulfate and nitrate were hardly produced on the surface of dust particles that were originated from the deserts areas in northwestern China. This is because the dust particles were in the postfrontal air, where the temperature was low and the relative humidity was small due to the adiabatic properties of the air mass. There are a number studies reporting that sulfate and nitrate had been efficiently produced on mineral particles in inland areas of China. However, those mineral particles were more likely from the local areas rather than from the desert areas. Our observations in the coastal areas of Japan, which is located in the downstream areas of the Asian continent and surrounded by sea areas revealed that dust particles appearing there frequently contained sulfate and nitrate, indicating sulfate and nitrate had been efficiently produced on the surface of the particles when the particles traveled in the marine air between China and Japan.

  2. Pre-Columbian archaeological ruins are revealed through Costa Rican rain forest in this photo taken during NASA's AirSAR 2004 campaign

    NASA Image and Video Library

    2004-03-05

    Pre-Columbian archaeological ruins are revealed through Costa Rican rain forest in this photo taken during NASA's AirSAR 2004 Mesoamerica campaign. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that uses an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. The radar, developed by NASA's Jet Propulsion Laboratory, can penetrate clouds and also collect data at night. Its high-resolution sensors operate at multiple wavelengths and modes, allowing AirSAR to see beneath treetops, through thin sand, and dry snow pack. Much of the archaeological evidence needed to understand Pre-Columbian societies in Central America comes from features on the landscape. Difficult terrain and logistics have limited ground data collection. AirSAR helped to detect signs of ancient civilizations hidden beneath the forest. Its images will shed insights into the way modern humans interact with their landscape, and how ancient peoples lived and what became of their civilizations.

  3. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING AIR SAMPLES FOR ANALYSIS OF POLAR PERSISTENT ORGANIC POLLUTANTS (SOP-5.13)

    EPA Science Inventory

    The method for extracting and preparing indoor and outdoor air samples for analysis of polar persistent organic pollutants is summarized in this SOP. It covers the preparation of samples that are to be analyzed by gas chromatography/mass spectrometry.

  4. COMPARISON OF MOLD CONCENTRATIONS IN INDOOR AND OUTDOOR AIR SAMPLED SIMULTANEOUSLY AND THEN QUANTIFIED BY MSQPCR

    EPA Science Inventory

    Mold specific quantitative PCR (MSQPCR) was used to measure the concentrations of the 36 mold species in indoor and outdoor air samples that were taken simultaneously for 48 hours in and around 17 homes in Cincinnati, Ohio. The total spore concentrations of 353 per m3...

  5. Development of size-selective sampling of Bacillus anthracis surrogate spores from simulated building air intake mixtures for analysis via laser-induced breakdown spectroscopy.

    PubMed

    Gibb-Snyder, Emily; Gullett, Brian; Ryan, Shawn; Oudejans, Lukas; Touati, Abderrahmane

    2006-08-01

    Size-selective sampling of Bacillus anthracis surrogate spores from realistic, common aerosol mixtures was developed for analysis by laser-induced breakdown spectroscopy (LIBS). A two-stage impactor was found to be the preferential sampling technique for LIBS analysis because it was able to concentrate the spores in the mixtures while decreasing the collection of potentially interfering aerosols. Three common spore/aerosol scenarios were evaluated, diesel truck exhaust (to simulate a truck running outside of a building air intake), urban outdoor aerosol (to simulate common building air), and finally a protein aerosol (to simulate either an agent mixture (ricin/anthrax) or a contaminated anthrax sample). Two statistical methods, linear correlation and principal component analysis, were assessed for differentiation of surrogate spore spectra from other common aerosols. Criteria for determining percentages of false positives and false negatives via correlation analysis were evaluated. A single laser shot analysis of approximately 4 percent of the spores in a mixture of 0.75 m(3) urban outdoor air doped with approximately 1.1 x 10(5) spores resulted in a 0.04 proportion of false negatives. For that same sample volume of urban air without spores, the proportion of false positives was 0.08.

  6. A HUPO test sample study reveals common problems in mass spectrometry-based proteomics

    PubMed Central

    Bell, Alexander W.; Deutsch, Eric W.; Au, Catherine E.; Kearney, Robert E.; Beavis, Ron; Sechi, Salvatore; Nilsson, Tommy; Bergeron, John J.M.

    2009-01-01

    We carried out a test sample study to try to identify errors leading to irreproducibility, including incompleteness of peptide sampling, in LC-MS-based proteomics. We distributed a test sample consisting of an equimolar mix of 20 highly purified recombinant human proteins, to 27 laboratories for identification. Each protein contained one or more unique tryptic peptides of 1250 Da to also test for ion selection and sampling in the mass spectrometer. Of the 27 labs, initially only 7 labs reported all 20 proteins correctly, and only 1 lab reported all the tryptic peptides of 1250 Da. Nevertheless, a subsequent centralized analysis of the raw data revealed that all 20 proteins and most of the 1250 Da peptides had in fact been detected by all 27 labs. The centralized analysis allowed us to determine sources of problems encountered in the study, which include missed identifications (false negatives), environmental contamination, database matching, and curation of protein identifications. Improved search engines and databases are likely to increase the fidelity of mass spectrometry-based proteomics. PMID:19448641

  7. Cryogenic separation of an oxygen-argon mixture in natural air samples for the determination of isotope and molecular ratios.

    PubMed

    Keedakkadan, Habeeb Rahman; Abe, Osamu

    2015-04-30

    The separation and purification of oxygen-argon mixtures are critical in the high-precision analysis of Δ(17) O and δ(O2 /Ar) for geochemical applications. At present, chromatographic methods are used for the separation and purification of oxygen-argon mixtures or pure oxygen, but these methods require the use of high-purity helium as a carrier gas. Considerable interest has been expressed in the development of a helium-free cryogenic separation of oxygen-argon mixtures in natural air samples. The precise and simplified cryogenic separation of oxygen-argon mixtures from natural air samples presented here was made possible using a single 5A (30/60 mesh) molecular sieve column. The method involves the trapping of eluted gases using molecular sieves at liquid nitrogen temperature, which is associated with isotopic fractionation. We tested the proposed method for the determination of isotopic fractionations during the gas exchange between water and atmospheric air at equilibrium. The dependency of fractionation was studied at different water temperatures and for different methods of equilibration (bubbling and stirring). Isotopic and molecular fractionations during gas desorption from molecular sieves were studied for different amounts and types of molecular sieves. Repeated measurements of atmospheric air yielded a reproducibility (±SD) of 0.021 ‰, 0.044 ‰, 15 per meg and 1.9 ‰ for δ(17) O, δ(18) O, Δ(17) O and δ(O2 /Ar) values, respectively. We applied the method to determine equilibrium isotope fractionation during gas exchange between air and water. Consistent δ(18) O and Δ(17) O results were obtained with the latest two studies, whereas there was a significant difference in δ(18) O values between seawater and deionized water. We have revised a helium-free, cryogenic separation of oxygen-argon mixtures in natural air samples for isotopic and molecular ratio analysis. The use of a single 13X (1/8" pellet) molecular sieve yielded the smallest isotopic

  8. A Comparison Study of Sampling and Analyzing Volatile Organic Compounds in Air in Kuwait by Using Tedlar Bags/Canisters and GC-MS with a Cryogenic Trap

    PubMed Central

    Tang, Hongmao; Beg, Khaliq R.; Al-Otaiba, Yousef

    2006-01-01

    Kuwait experiences desert climatic weather. Due to the extreme hot and dry conditions in this country, some analytical phenomena have been discovered. Therefore, a systematic study of sampling and analyzing volatile organic compounds in air by using GC-MS with a cryogenic trap is reported in this paper. This study included comparisons of using different sample containers such as Tedlar bags and SUMMA canisters, and different cryogenic freezing-out air volumes in the trap. Calibration curves for different compounds and improvement of replicated analysis results were also reported here. The study found that using different sample containers produced different results. Analysis of ambient air samples collected in Tedlar bags obtained several volatile organic compounds with large concentrations compared to using SUMMA canisters. Therefore, to choose a sample container properly is a key element for successfully completing a project. Because GC-MS with a cryogenic trap often generates replicated results with poor agreement, an internal standard added to gas standards and air samples by using a gas syringe was tested. The study results proved that it helped to improve the replicated results. PMID:16699723

  9. A comparison study of sampling and analyzing volatile organic compounds in air in Kuwait by using Tedlar bags/canisters and GC-MS with a cryogenic trap.

    PubMed

    Tang, Hongmao; Beg, Khaliq R; Al-Otaiba, Yousef

    2006-05-12

    Kuwait experiences desert climatic weather. Due to the extreme hot and dry conditions in this country, some analytical phenomena have been discovered. Therefore, a systematic study of sampling and analyzing volatile organic compounds in air by using GC-MS with a cryogenic trap is reported in this paper. This study included comparisons of using different sample containers such as Tedlar bags and SUMMA canisters, and different cryogenic freezing-out air volumes in the trap. Calibration curves for different compounds and improvement of replicated analysis results were also reported here. The study found that using different sample containers produced different results. Analysis of ambient air samples collected in Tedlar bags obtained several volatile organic compounds with large concentrations compared to using SUMMA canisters. Therefore, to choose a sample container properly is a key element for successfully completing a project. Because GC-MS with a cryogenic trap often generates replicated results with poor agreement, an internal standard added to gas standards and air samples by using a gas syringe was tested. The study results proved that it helped to improve the replicated results.

  10. Venturi air-jet vacuum ejectors for high-volume atmospheric sampling on aircraft platforms

    NASA Technical Reports Server (NTRS)

    Hill, Gerald F.; Sachse, Glen W.; Young, Douglas C.; Wade, Larry O.; Burney, Lewis G.

    1992-01-01

    Documentation of the installation and use of venturi air-jet vacuum ejectors for high-volume atmospheric sampling on aircraft platforms is presented. Information on the types of venturis that are useful for meeting the pumping requirements of atmospheric-sampling experiments is also presented. A description of the configuration and installation of the venturi system vacuum line is included with details on the modifications that were made to adapt a venturi to the NASA Electra aircraft at GSFC, Wallops Flight Facility. Flight test results are given for several venturis with emphasis on applications to the Differential Absorption Carbon Monoxide Measurement (DACOM) system at LaRC. This is a source document for atmospheric scientists interested in using the venturi systems installed on the NASA Electra or adapting the technology to other aircraft.

  11. Sampling of trace volatile metal(loid) compounds in ambient air using polymer bags: a convenient method.

    PubMed

    Haas, K; Feldmann, J

    2000-09-01

    The sampling of volatile metal(loid) compounds (VOMs) such as hydrides, methylated, and permethylated species of arsenic, antimony, and tin is described using Tedlar bags. Advantages as well as limitations and constraints are discussed and compared to other widely used sampling techniques within this area, namely, stainless steel canisters, cryotrapping, and solid adsorbent cartridges. To prove the suitability of Tedlar bags for the sampling of volatile metal(loid) compounds, series of stability tests have been run using both laboratory synthetic and real samples analyzed periodically after increasing periods of storage. The samples have been stored in the dark at 20 degrees C and at 50 degrees C. Various volatile arsenic species (AsH3, MeAsH2, Me2AsH, Me3As), tin species (SnH4, MeSnH3, Me2SnH2, Me3SnH, Me4Sn, BuSnH3), and antimony species (SbH3, MeSbH2, Me2SbH, Me3Sb) have been generated using hydride generation methodology and mixed with moisturized air. Three static gaseous atmospheres with concentrations of 0.3-18 ng/L for the various compounds have been generated in Tedlar bags, and the stability of the VOMs has been monitored over a period of 5 weeks. Sewage sludge digester gas samples have been stored only at 20 degrees C for a period of 48 h. Cryotrapping GC/ICPMS has been used for the determination of the VOMs with a relative standard deviation of 5% for 100 pg. After 8 h, the recovery rate of all the compounds in the air atmospheres was better than 95% at 20 and 50 degrees C, whereas the recovery after 24 h was found to be between 81 and 99% for all VOMs at 20 and 50 degrees C except for Me3Sb and Me3As. These species show a loss between 48 and 73% at both temperatures. After 5 weeks at 20 degrees C, a loss of only 25-50% for arsine and stibine and the above-mentioned tin compounds was determined. Only Me3Sb, Me3Bi, and Me2Te were present in the digester gas sample. After 24 h, losses of 44, 10, and 12%, respectively, could be determined. Given these

  12. A passive air sampler for characterizing the vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air.

    PubMed

    Zhang, Yuzhong; Deng, Shuxing; Liu, Yanan; Shen, Guofeng; Li, Xiqing; Cao, Jun; Wang, Xilong; Reid, Brian; Tao, Shu

    2011-03-01

    Air-soil exchange is an important process governing the fate of polycyclic aromatic hydrocarbons (PAHs). A novel passive air sampler was designed and tested for measuring the vertical concentration profile of 4 low molecular weight PAHs in gaseous phase (PAH(LMW4)) in near soil surface air. Air at various heights from 5 to 520 mm above the ground was sampled by polyurethane foam disks held in down-faced cartridges. The samplers were tested at three sites: A: an extremely contaminated site, B: a site near A, and C: a background site on a university campus. Vertical concentration gradients were revealed for PAH(LMW4) within a thin layer close to soil surface at the three sites. PAH concentrations either decreased (Site A) or increased (Sites B and C) with height, suggesting either deposition to or evaporation from soils. The sampler is a useful tool for investigating air-soil exchange of gaseous phase semi-volatile organic chemicals. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. EPA's Response to the February 2014 Release of Radioactive Material from the Waste Isolation Pilot Plant (WIPP): EPA's WIPP Air Sampling Data from April 2014

    EPA Pesticide Factsheets

    In April 2014, U.S. Environmental Protection Agency (EPA) environmental monitoring and assessment team members reviewed DOE's air sampling plan, visited DOE's air samplers and placed air samplers onsite near existing DOE samplers to corroborate results.

  14. Atmospheric CO2 Records from Sites in the Scripps Institution of Oceanography (SIO) Air Sampling Network (1985 - 2007)

    DOE Data Explorer

    Keeling, R. F. [Scripps Institution of Oceanography (SIO) University of California, La Jolla, California (USA); Piper, S. C. [Scripps Institution of Oceanography (SIO) University of California, La Jolla, California (USA); Bollenbacher, A. F. [Scripps Institution of Oceanography (SIO) University of California, La Jolla, California (USA); Walker , J. S. [Scripps Institution of Oceanography (SIO) University of California, La Jolla, California (USA)

    2008-05-01

    At Alert weekly air samples are collected in 5-L evacuated glass flasks exposed in triplicate. Flasks are returned to the SIO for CO2 determinations, which are made using an Applied Physics Corporation nondispersive infrared gas analyzer. In May 1983, the CO2-in-N2 calibration gases were replaced with CO2-in-air calibration gases, which are currently used (Keeling et al. 2002). Data are in terms of the Scripps "03A" calibration scale. On the basis of flask samples collected at Alert and analyzed by SIO, the annual average of the fitted monthly concentrations CO2 rose from 348.48 ppmv in 1986 to 384.84 ppmv in 2007. This represents an average annual growth rate of 1.73 ppmv per year at Alert.

  15. Use of Whole-Genome Sequencing to Link Burkholderia pseudomallei from Air Sampling to Mediastinal Melioidosis, Australia

    PubMed Central

    Price, Erin P.; Mayo, Mark; Kaestli, Mirjam; Theobald, Vanessa; Harrington, Ian; Harrington, Glenda; Sarovich, Derek S.

    2015-01-01

    The frequency with which melioidosis results from inhalation rather than percutaneous inoculation or ingestion is unknown. We recovered Burkholderia pseudomallei from air samples at the residence of a patient with presumptive inhalational melioidosis and used whole-genome sequencing to link the environmental bacteria to B. pseudomallei recovered from the patient. PMID:26488732

  16. Quantitative trace analysis of polyfluorinated alkyl substances (PFAS) in ambient air samples from Mace Head (Ireland): A method intercomparison

    NASA Astrophysics Data System (ADS)

    Jahnke, Annika; Barber, Jonathan L.; Jones, Kevin C.; Temme, Christian

    A method intercomparison study of analytical methods for the determination of neutral, volatile polyfluorinated alkyl substances (PFAS) was carried out in March, 2006. Environmental air samples were collected in triplicate at the European background site Mace Head on the west coast of Ireland, a site dominated by 'clean' westerly winds coming across the Atlantic. Extraction and analysis were performed at two laboratories active in PFAS research using their in-house methods. Airborne polyfluorinated telomer alcohols (FTOHs), fluorooctane sulfonamides and sulfonamidoethanols (FOSAs/FOSEs) as well as additional polyfluorinated compounds were investigated. Different native and isotope-labelled internal standards (IS) were applied at various steps in the analytical procedure to evaluate the different quantification strategies. Field blanks revealed no major blank problems. European background concentrations observed at Mace Head were found to be in a similar range to Arctic data reported in the literature. Due to trace-levels at the remote site, only FTOH data sets were complete and could therefore be compared between the laboratories. Additionally, FOSEs could partly be included. Data comparison revealed that despite the challenges inherent in analysis of airborne PFAS and the low concentrations, all methods applied in this study obtained similar results. However, application of isotope-labelled IS early in the analytical procedure leads to more precise results and is therefore recommended.

  17. Evaluation of sampling methods for measuring exposure to volatile inorganic acids in workplace air. Part 1: sampling hydrochloric acid (HCl) and nitric acid (HNO₃) from a test gas atmosphere.

    PubMed

    Howe, Alan; Musgrove, Darren; Breuer, Dietmar; Gusbeth, Krista; Moritz, Andreas; Demange, Martine; Oury, Véronique; Rousset, Davy; Dorotte, Michel

    2011-08-01

    Historically, workplace exposure to the volatile inorganic acids hydrochloric acid (HCl) and nitric acid (HNO(3)) has been determined mostly by collection on silica gel sorbent tubes and analysis of the corresponding anions by ion chromatography (IC). However, HCl and HNO(3) can be present in workplace air in the form of mist as well as vapor, so it is important to sample the inhalable fraction of airborne particles. As sorbent tubes exhibit a low sampling efficiency for inhalable particles, a more suitable method was required. This is the first of two articles on "Evaluation of Sampling Methods for Measuring Exposure to Volatile Inorganic Acids in Workplace Air" and describes collaborative sampling exercises carried out to evaluate an alternative method for sampling HCl and HNO(3) using sodium carbonate-impregnated filters. The second article describes sampling capacity and breakthrough tests. The method was found to perform well and a quartz fiber filter impregnated with 500 μL of 1 M Na(2)CO(3) (10% (m/v) Na(2)CO(3)) was found to have sufficient sampling capacity for use in workplace air measurement. A pre-filter is required to remove particulate chlorides and nitrates that when present would otherwise result in a positive interference. A GSP sampler fitted with a plastic cone, a closed face cassette, or a plastic IOM sampler were all found to be suitable for mounting the pre-filter and sampling filter(s), but care has to be taken with the IOM sampler to ensure that the sampler is tightly closed to avoid leaks. HCl and HNO(3) can react with co-sampled particulate matter on the pre-filter, e.g., zinc oxide, leading to low results, and stronger acids can react with particulate chlorides and nitrates removed by the pre-filter to liberate HCl and HNO(3), which are subsequently collected on the sampling filter, leading to high results. However, although there is this potential for both positive and negative interferences in the measurement, these are unavoidable

  18. Influential role of black carbon in the soil-air partitioning of polychlorinated biphenyls (PCBs) in the Indus River Basin, Pakistan.

    PubMed

    Ali, Usman; Syed, Jabir Hussain; Mahmood, Adeel; Li, Jun; Zhang, Gan; Jones, Kevin C; Malik, Riffat Naseem

    2015-09-01

    Levels of polychlorinated biphenyls (PCBs) were assessed in surface soils and passive air samples from the Indus River Basin, and the influential role of black carbon (BC) in the soil-air partitioning process was examined. ∑26-PCBs ranged between 0.002-3.03 pg m(-3) and 0.26-1.89 ng g(-1) for passive air and soil samples, respectively. Lower chlorinated (tri- and tetra-) PCBs were abundant in both air (83.9%) and soil (92.1%) samples. Soil-air partitioning of PCBs was investigated through octanol-air partition coefficients (KOA) and black carbon-air partition coefficients (KBC-A). The results of the paired-t test revealed that both models showed statistically significant agreement between measured and predicted model values for the PCB congeners. Ratios of fBCKBC-AδOCT/fOMKOA>5 explicitly suggested the influential role of black carbon in the retention and soil-air partitioning of PCBs. Lower chlorinated PCBs were strongly adsorbed and retained by black carbon during soil-air partitioning because of their dominance at the sampling sites and planarity effect. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Does the Exposure of Urine Samples to Air Affect Diagnostic Tests for Urine Acidification?

    PubMed Central

    Yi, Joo-Hark; Shin, Hyun-Jong; Kim, Sun-Moon; Han, Sang-Woong; Oh, Man-Seok

    2012-01-01

    Summary Background and objectives For accurate measurement of pH, urine collection under oil to limit the escape of CO2 on air exposure is recommended. This study aims to test the hypothesis that urine collection under oil is not necessary in acidic urine in which bicarbonate and CO2 are minor buffers, because loss of CO2 would have little effect on its pH. Design, setting, participants, & measurements One hundred consecutive random urine samples were collected under oil and analyzed for pH, pCO2, and HCO3− immediately and after 5 minutes of vigorous shaking in uncovered flasks to allow CO2 escape. Results The pH values in 97 unshaken samples ranged from 5.03 to 6.83. With shaking, urine pCO2 decreased by 76%, whereas urine HCO3− decreased by 60%. Meanwhile, urine baseline median pH (interquartile range) of 5.84 (5.44–6.25) increased to 5.93 (5.50–6.54) after shaking (ΔpH=0.12 [0.07–0.29], P<0.001). ΔpH with pH≤6.0 was significantly lower than the ΔpH with pH>6.0 (0.08 [0.05–0.12] versus 0.36 [0.23–0.51], P<0.001). Overall, the lower the baseline pH, the smaller the ΔpH. Conclusions The calculation of buffer reactions in a hypothetical acidic urine predicted a negligible effect on urine pH on loss of CO2 by air exposure, which was empirically proven by the experimental study. Therefore, exposure of urine to air does not substantially alter the results of diagnostic tests for urine acidification, and urine collection under oil is not necessary. PMID:22700881

  20. Collection and analysis of NASA clean room air samples

    NASA Technical Reports Server (NTRS)

    Sheldon, L. S.; Keever, J.

    1985-01-01

    The environment of the HALOE assembly clean room at NASA Langley Research Center is analyzed to determine the background levels of airborne organic compounds. Sampling is accomplished by pumping the clean room air through absorbing cartridges. For volatile organics, cartridges are thermally desorbed and then analyzed by gas chromatography and mass spectrometry, compounds are identified by searching the EPA/NIH data base using an interactive operator INCOS computer search algorithm. For semivolatile organics, cartridges are solvent entracted and concentrated extracts are analyzed by gas chromatography-electron capture detection, compound identification is made by matching gas chromatogram retention times with known standards. The detection limits for the semivolatile organics are; 0.89 ng cu m for dioctylphlhalate (DOP) and 1.6 ng cu m for polychlorinated biphenyls (PCB). The detection limit for volatile organics ranges from 1 to 50 parts per trillion. Only trace quantities of organics are detected, the DOP levels do not exceed 2.5 ng cu m and the PCB levels do not exceed 454 ng cu m.

  1. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING AIR SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.12)

    EPA Science Inventory

    The method is for extracting an indoor and outdoor air sample consisting of a quartz fiber filter and an XAD-2 cartridge for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass...

  2. Proteomics Analysis of Tissue Samples Reveals Changes in Mitochondrial Protein Levels in Parathyroid Hyperplasia over Adenoma

    PubMed Central

    AKPINAR, GURLER; KASAP, MURAT; CANTURK, NUH ZAFER; ZULFIGAROVA, MEHIN; ISLEK, EYLÜL ECE; GULER, SERTAC ATA; SIMSEK, TURGAY; CANTURK, ZEYNEP

    2017-01-01

    Background/Aim: To unveil the pathophysiology of primary hyperparathyroidism, molecular details of parathyroid hyperplasia and adenoma have to be revealed. Such details will provide the tools necessary for differentiation of these two look-alike diseases. Therefore, in the present study, a comparative proteomic study using postoperative tissue samples from the parathyroid adenoma and parathyroid hyperplasia patients was performed. Materials and Methods: Protein extracts were prepared from tissue samples (n=8 per group). Protein pools were created for each group and subjected to DIGE and conventional 2DE. Following image analysis, spots representing the differentially regulated proteins were excised from the and used for identification via MALDI-TOF/TOF analysis. Results: The identities of 40 differentially-expressed proteins were revealed. Fourteen of these proteins were over-expressed in the hyperplasia while 26 of them were over-expressed in the adenoma. Conclusion: Most proteins found to be over-expressed in the hyperplasia samples were mitochondrial, underlying the importance of the mitochondrial activity as a potential biomarker for differentiation of parathyroid hyperplasia from adenoma. PMID:28446534

  3. Evaluation of sampling methods for toxicological testing of indoor air particulate matter.

    PubMed

    Tirkkonen, Jenni; Täubel, Martin; Hirvonen, Maija-Riitta; Leppänen, Hanna; Lindsley, William G; Chen, Bean T; Hyvärinen, Anne; Huttunen, Kati

    2016-09-01

    There is a need for toxicity tests capable of recognizing indoor environments with compromised air quality, especially in the context of moisture damage. One of the key issues is sampling, which should both provide meaningful material for analyses and fulfill requirements imposed by practitioners using toxicity tests for health risk assessment. We aimed to evaluate different existing methods of sampling indoor particulate matter (PM) to develop a suitable sampling strategy for a toxicological assay. During three sampling campaigns in moisture-damaged and non-damaged school buildings, we evaluated one passive and three active sampling methods: the Settled Dust Box (SDB), the Button Aerosol Sampler, the Harvard Impactor and the National Institute for Occupational Safety and Health (NIOSH) Bioaerosol Cyclone Sampler. Mouse RAW264.7 macrophages were exposed to particle suspensions and cell metabolic activity (CMA), production of nitric oxide (NO) and tumor necrosis factor (TNFα) were determined after 24 h of exposure. The repeatability of the toxicological analyses was very good for all tested sampler types. Variability within the schools was found to be high especially between different classrooms in the moisture-damaged school. Passively collected settled dust and PM collected actively with the NIOSH Sampler (Stage 1) caused a clear response in exposed cells. The results suggested the higher relative immunotoxicological activity of dust from the moisture-damaged school. The NIOSH Sampler is a promising candidate for the collection of size-fractionated PM to be used in toxicity testing. The applicability of such sampling strategy in grading moisture damage severity in buildings needs to be developed further in a larger cohort of buildings.

  4. Comparing the VOC emissions between air-dried and heat-treated Scots pine wood

    NASA Astrophysics Data System (ADS)

    Manninen, Anne-Marja; Pasanen, Pertti; Holopainen, Jarmo K.

    The emissions of volatile organic compounds (VOCs) from air-dried Scots pine wood and from heat-treated Scots pine wood were compared with GC-MS analysis. Air-dried wood blocks released about 8 times more total VOCs than heat-treated (24 h at 230°C) ones. Terpenes were clearly the main compound group in the air-dried wood samples, whereas aldehydes and carboxylic acids and their esters dominated in the heat-treated wood samples. Only 14 compounds out of 41 identified individual compounds were found in both wood samples indicating considerable changes in VOC emission profile during heat-treatment process. Of individual compounds α-pinene, 3-carene and hexanal were the most abundant ones in the air-dried wood. By contrast, in the heat-treated wood 2-furancarboxaldehyde, acetic acid and 2-propanone were the major compounds of VOC emission. Current emission results reveal that significant chemical changes have occurred, and volatile monoterpenes and other low-molecular-weight compounds have evaporated from the wood during the heat-treatment process when compared to air-dried wood. Major chemical changes detected in VOC emissions are explained by the thermal degradation and oxidation of main constituents in wood. The results suggest that if heat-treated wood is used in interior carpentry, emissions of monoterpenes are reduced compared to air-dried wood, but some irritating compounds might be released into indoor air.

  5. Relationships between drought, heat and air humidity responses revealed by transcriptome-metabolome co-analysis.

    PubMed

    Georgii, Elisabeth; Jin, Ming; Zhao, Jin; Kanawati, Basem; Schmitt-Kopplin, Philippe; Albert, Andreas; Winkler, J Barbro; Schäffner, Anton R

    2017-07-10

    Elevated temperature and reduced water availability are frequently linked abiotic stresses that may provoke distinct as well as interacting molecular responses. Based on non-targeted metabolomic and transcriptomic measurements from Arabidopsis rosettes, this study aims at a systematic elucidation of relevant components in different drought and heat scenarios as well as relationships between molecular players of stress response. In combined drought-heat stress, the majority of single stress responses are maintained. However, interaction effects between drought and heat can be discovered as well; these relate to protein folding, flavonoid biosynthesis and growth inhibition, which are enhanced, reduced or specifically induced in combined stress, respectively. Heat stress experiments with and without supplementation of air humidity for maintenance of vapor pressure deficit suggest that decreased relative air humidity due to elevated temperature is an important component of heat stress, specifically being responsible for hormone-related responses to water deprivation. Remarkably, this "dry air effect" is the primary trigger of the metabolomic response to heat. In contrast, the transcriptomic response has a substantial temperature component exceeding the dry air component and including up-regulation of many transcription factors and protein folding-related genes. Data level integration independent of prior knowledge on pathways and condition labels reveals shared drought and heat responses between transcriptome and metabolome, biomarker candidates and co-regulation between genes and metabolic compounds, suggesting novel players in abiotic stress response pathways. Drought and heat stress interact both at transcript and at metabolite response level. A comprehensive, non-targeted view of this interaction as well as non-interacting processes is important to be taken into account when improving tolerance to abiotic stresses in breeding programs. Transcriptome and metabolome

  6. Results from Geothermal Logging, Air and Core-Water Chemistry Sampling, Air Injection Testing and Tracer Testing in the Northern Ghost Dance Fault, YUCCA Mountain, Nevada, November 1996 to August 1998

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lecain, G.D.; Anna, L.O.; Fahy, M.F.

    1998-08-01

    Geothermal logging, air and core-water chemistry sampling, air-injection testing, and tracer testing were done in the northern Ghost Dance Fault at Yucca Mountain, Nevada, from November 1996 to August 1998. The study was done by the U.S. Geological Survey, in cooperation with the U.S. Department of Energy. The fault-testing drill room and test boreholes were located in the crystal-poor, middle nonlithophysal zone of the Topopah Spring Tuff, a tuff deposit of Miocene age. The drill room is located off the Yucca Mountain underground Exploratory Studies Facility at about 230 meters below ground surface. Borehole geothermal logging identified a temperature decreasemore » of 0.1 degree Celsius near the Ghost Dance Fault. The temperature decrease could indicate movement of cooler air or water, or both, down the fault, or it may be due to drilling-induced evaporative or adiabatic cooling. In-situ pneumatic pressure monitoring indicated that barometric pressure changes were transmitted from the ground surface to depth through the Ghost Dance Fault. Values of carbon dioxide and delta carbon-13 from gas samples indicated that air from the underground drill room had penetrated the tuff, supporting the concept of a well-developed fracture system. Uncorrected carbon-14-age estimates from gas samples ranged from 2,400 to 4,500 years. Tritium levels in borehole core water indicated that the fault may have been a conduit for the transport of water from the ground surface to depth during the last 100 years.« less

  7. Unexpected high 35S concentration revealing strong downward transport of stratospheric air during the monsoon transitional period in East Asia

    NASA Astrophysics Data System (ADS)

    Lin, Mang; Zhang, Zhisheng; Su, Lin; Su, Binbin; Liu, Lanzhong; Tao, Jun; Fung, Jimmy C. H.; Thiemens, Mark H.

    2016-03-01

    October is the monsoon transitional period in East Asia (EA) involving a series of synoptic activities that may enhance the downward transport of stratospheric air to the planetary boundary layer (PBL). Here we use cosmogenic 35S in sulfate aerosols (35SO42-) as a tracer for air masses originating from the stratosphere and transported downward to quantify these mixing processes. From 1 year 35SO42- measurements (March 2014 to February 2015) at a background station in EA we find remarkably enhanced 35SO42- concentration (3150 atoms m-3) in October, the highest value ever reported for natural sulfate aerosols. A four-box 1-D model and meteorological analysis reveal that strong downward transport from the free troposphere is a vital process entraining aged stratospheric air masses to the PBL. The aged stratospheric masses are accumulated in the PBL, accelerating the SO2 transformation to SO42-. Implications for the tropospheric O3 budget and the CO2 biogeochemical cycle are discussed.

  8. US EPA Base Study Standard Operating Procedure for Sampling Volatile Organic Compounds in Indoor Air Using Evacuated Canisters

    EPA Pesticide Factsheets

    The objective of this procedure is to collect a representative sample of air containing volatile organic compound (VOC) contaminants present in an indoor environment using an evacuated canister, and to subsequently analyze the concentration of VOCs, as selected by EPA.

  9. Measurements of CO2 Mole Fractionand δ13C in Archived Air Samples from Cape Meares, Oregon (USA) 1977 - 1998

    NASA Astrophysics Data System (ADS)

    Clark, O.; Rice, A. L.

    2017-12-01

    Carbon dioxide (CO2) is the most abundant, anthropogenically forced greenhouse gas (GHG) in the global atmosphere. Emissions of CO2 account for approximately 75% of the world's total GHG emissions. Atmospheric concentrations of CO2 are higher now than they've been at any other time in the past 800,000 years. Currently, the global mean concentration exceeds 400 ppm. Today, global networks regularly monitor CO2 concentrations and isotopic composition (δ13C and δ18O). However, past data is sparse. Over 200 ambient air samples from Cape Meares, Oregon (45.5°N, 124.0°W), a coastal site in Western United States, were obtained by researchers at Oregon Institute of Science and Technology (OGI, now Oregon Health & Science University), between the years of 1977 and 1998 as part of a global monitoring program of six different sites in the polar, middle, and tropical latitudes of the Northern and Southern Hemispheres. Air liquefaction was used to compress approximately 1000L of air (STP) to 30bar, into 33L electropolished (SUMMA) stainless steel canisters. Select archived air samples from the original network are maintained at Portland State University (PSU) Department of Physics. These archived samples are a valuable look at changing atmospheric concentrations of CO2 and δ13C, which can contribute to a better understanding of changes in sources during this time. CO2 concentrations and δ13C of CO2 were measured at PSU, with a Picarro Cavity Ringdown Spectrometer, model G1101-i analytical system. This study presents the analytical methods used, calibration techniques, precision, and reproducibility. Measurements of select samples from the archive show rising CO2 concentrations and falling δ13C over the 1977 to 1998 period, compatible with previous observations and rising anthropogenic sources of CO2. The resulting data set was statistically analyzed in MATLAB. Results of preliminary seasonal and secular trends from the archive samples are presented.

  10. Breathing zone air sampler

    DOEpatents

    Tobin, John

    1989-01-01

    A sampling apparatus is provided which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

  11. Exploring prenatal outdoor air pollution, birth outcomes and neonatal health care utilization in a nationally representative sample

    PubMed Central

    Trasande, Leonardo; Wong, Kendrew; Roy, Angkana; Savitz, David A.; Thurston, George

    2015-01-01

    The impact of air pollution on fetal growth remains controversial, in part, because studies have been limited to sub-regions of the United States with limited variability. No study has examined air pollution impacts on neonatal health care utilization. We performed descriptive, univariate and multivariable analyses on administrative hospital record data from 222,359 births in the 2000, 2003 and 2006 Kids Inpatient Database linked to air pollution data drawn from the US Environmental Protection Agency’s Aerometric Information Retrieval System. In this study, air pollution exposure during the birth month was estimated based on birth hospital address. Although air pollutants were not individually associated with mean birth weight, a three-pollutant model controlling for hospital characteristics, demographics, and birth month identified 9.3% and 7.2% increases in odds of low birth weight and very low birth weight for each µg/m3 increase in PM2.5 (both P<0.0001). PM2.5 and NO2 were associated with −3.0% odds/p.p.m. and +2.5% odds/p.p.b. of preterm birth, respectively (both P<0.0001). A four-pollutant multivariable model indicated a 0.05 days/p.p.m. NO2 decrease in length of the birth hospitalization (P=0.0061) and a 0.13 days increase/p.p.m. CO (P=0.0416). A $1166 increase in per child costs was estimated for the birth hospitalization per p.p.m. CO (P=0.0002) and $964 per unit increase in O3 (P=0.0448). A reduction from the 75th to the 25th percentile in the highest CO quartile for births predicts annual savings of $134.7 million in direct health care costs. In a national, predominantly urban, sample, air pollutant exposures during the month of birth are associated with increased low birth weight and neonatal health care utilization. Further study of this database, with enhanced control for confounding, improved exposure assessment, examination of exposures across multiple time windows in pregnancy, and in the entire national sample, is supported by these initial

  12. Assessment of Air Quality in the Shuttle and International Space Station (ISS) Based on Samples Returned by STS-102 at the Conclusion of 5A.1

    NASA Technical Reports Server (NTRS)

    James, John T.

    2001-01-01

    The toxicological assessment of air samples returned at the end of the STS-102 (5A.1) flight to the ISS is reported. ISS air samples were taken in late February 2001 from the Service Module, FGB, and U.S. Laboratory using grab sample canisters (GSCs) and/or formaldehyde badges . A "first-entry" sample of the multipurpose logistics module (MPLM) atmosphere was taken with a GSC, and preflight and end-of-mission samples were obtained from Discovery using GSCs. Analytical methods have not changed from earlier reports, and all quality control measures were met for the data presented herein. The two general criteria used to assess air quality are the total-non-methane-volatile organic hydrocarbons (NMVOCs) and the total T-value (minus the CO2 contribution). Control of atmospheric alcohols is important to the water recovery system engineers, hence total alcohols were also assessed in each sample. Formaldehyde is quantified separately.

  13. A system for high-quality CO2 isotope analyses of air samples collected by the CARIBIC Airbus A340-600.

    PubMed

    Assonov, S; Taylor, P; Brenninkmeijer, C A M

    2009-05-01

    In 2007, JRC-IRMM began a series of atmospheric CO2 isotope measurements, with the focus on understanding instrumental effects, corrections as well as metrological aspects. The calibration approach at JRC-IRMM is based on use of a plain CO2 sample (working reference CO2) as a calibration carrier and CO2-air mixtures (in high-pressure cylinders) to determine the method-related correction under actual analytical conditions (another calibration carrier, in the same form as the samples). Although this approach differs from that in other laboratories, it does give a direct link to the primary reference NBS-19-CO2. It also helps to investigate the magnitude and nature for each of the instrumental corrections and allows for the quantification of the uncertainty introduced. Critical tests were focused on the instrumental corrections. It was confirmed that the use of non-symmetrical capillary crimping (an approach used here to deal with small samples) systematically modifies delta13C(CO2) and delta18O(CO2), with a clear dependence on the amount of extracted CO2. However, the calibration of CO2-air mixtures required the use of the symmetrical dual-inlet mode. As a proof of our approach, we found that delta13C(CO2) on extracts from mixtures agreed (within 0.010 per thousand) with values obtained from the 'mother' CO2 used for the mixtures. It was further found that very low levels of hydrocarbons in the pumping systems and the isotope ratio mass spectrometry (IRMS) instrument itself were critical. The m/z 46 values (consequently the calculated delta18O(CO2) values) are affected by several other effects with traces of air co-trapped with frozen CO2 being the most critical. A careful cryo-distillation of the extracted CO2 is recommended. After extensive testing, optimisation, and routine automated use, the system was found to give precise data on air samples that can be traced with confidence to the primary standards. The typical total combined uncertainty in delta13C(CO2) and

  14. High-Resolution Air Pollution Mapping with Google Street View Cars: Exploiting Big Data.

    PubMed

    Apte, Joshua S; Messier, Kyle P; Gani, Shahzad; Brauer, Michael; Kirchstetter, Thomas W; Lunden, Melissa M; Marshall, Julian D; Portier, Christopher J; Vermeulen, Roel C H; Hamburg, Steven P

    2017-06-20

    Air pollution affects billions of people worldwide, yet ambient pollution measurements are limited for much of the world. Urban air pollution concentrations vary sharply over short distances (≪1 km) owing to unevenly distributed emission sources, dilution, and physicochemical transformations. Accordingly, even where present, conventional fixed-site pollution monitoring methods lack the spatial resolution needed to characterize heterogeneous human exposures and localized pollution hotspots. Here, we demonstrate a measurement approach to reveal urban air pollution patterns at 4-5 orders of magnitude greater spatial precision than possible with current central-site ambient monitoring. We equipped Google Street View vehicles with a fast-response pollution measurement platform and repeatedly sampled every street in a 30-km 2 area of Oakland, CA, developing the largest urban air quality data set of its type. Resulting maps of annual daytime NO, NO 2 , and black carbon at 30 m-scale reveal stable, persistent pollution patterns with surprisingly sharp small-scale variability attributable to local sources, up to 5-8× within individual city blocks. Since local variation in air quality profoundly impacts public health and environmental equity, our results have important implications for how air pollution is measured and managed. If validated elsewhere, this readily scalable measurement approach could address major air quality data gaps worldwide.

  15. Enhancing indoor air quality -The air filter advantage.

    PubMed

    Vijayan, Vannan Kandi; Paramesh, Haralappa; Salvi, Sundeep Santosh; Dalal, Alpa Anil Kumar

    2015-01-01

    Air pollution has become the world's single biggest environmental health risk, linked to around 7 million deaths in 2012 according to a recent World Health Organisation (WHO) report. The new data further reveals a stronger link between, indoor and outdoor air pollution exposure and cardiovascular diseases, such as strokes and ischemic heart disease, as well as between air pollution and cancer. The role of air pollution in the development of respiratory diseases, including acute respiratory infections and chronic obstructive pulmonary diseases, is well known. While both indoor and outdoor pollution affect health, recent statistics on the impact of household indoor pollutants (HAP) is alarming. The WHO factsheet on HAP and health states that 3.8 million premature deaths annually - including stroke, ischemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer are attributed to exposure to household air pollution. Use of air cleaners and filters are one of the suggested strategies to improve indoor air quality. This review discusses the impact of air pollutants with special focus on indoor air pollutants and the benefits of air filters in improving indoor air quality.

  16. Evaluation of sequential extraction procedures for soluble and insoluble hexavalent chromium compounds in workplace air samples.

    PubMed

    Ashley, Kevin; Applegate, Gregory T; Marcy, A Dale; Drake, Pamela L; Pierce, Paul A; Carabin, Nathalie; Demange, Martine

    2009-02-01

    Because toxicities may differ for Cr(VI) compounds of varying solubility, some countries and organizations have promulgated different occupational exposure limits (OELs) for soluble and insoluble hexavalent chromium (Cr(VI)) compounds, and analytical methods are needed to determine these species in workplace air samples. To address this need, international standard methods ASTM D6832 and ISO 16740 have been published that describe sequential extraction techniques for soluble and insoluble Cr(VI) in samples collected from occupational settings. However, no published performance data were previously available for these Cr(VI) sequential extraction procedures. In this work, the sequential extraction methods outlined in the relevant international standards were investigated. The procedures tested involved the use of either deionized water or an ammonium sulfate/ammonium hydroxide buffer solution to target soluble Cr(VI) species. This was followed by extraction in a sodium carbonate/sodium hydroxide buffer solution to dissolve insoluble Cr(VI) compounds. Three-step sequential extraction with (1) water, (2) sulfate buffer and (3) carbonate buffer was also investigated. Sequential extractions were carried out on spiked samples of soluble, sparingly soluble and insoluble Cr(VI) compounds, and analyses were then generally carried out by using the diphenylcarbazide method. Similar experiments were performed on paint pigment samples and on airborne particulate filter samples collected from stainless steel welding. Potential interferences from soluble and insoluble Cr(III) compounds, as well as from Fe(II), were investigated. Interferences from Cr(III) species were generally absent, while the presence of Fe(II) resulted in low Cr(VI) recoveries. Two-step sequential extraction of spiked samples with (first) either water or sulfate buffer, and then carbonate buffer, yielded quantitative recoveries of soluble Cr(VI) and insoluble Cr(VI), respectively. Three-step sequential

  17. Assessment of Air Quality in the Shuttle and International Space Station (ISS) Based on Samples Returned by STS-105 at the Conclusion of 7A.1

    NASA Technical Reports Server (NTRS)

    James, John T.

    2001-01-01

    The toxicological assessment of air samples returned at the end of the STS-105 (7 A.1) flight to the ISS is reported. ISS air samples were taken in August 2001 from the Service Module, FGB, and U.S. Laboratory using grab sample canisters (GSCs) and/or formaldehyde badges. Preflight and end-of-mission samples were obtained from Discovery using GSCs. Analytical methods have not changed from earlier reports, and surrogate standard recoveries were 64-115%. Pressure tracking indicated no leaks in the canisters.

  18. Relative congener scaling of Polychlorinated dibenzo-p-dioxins and dibenzofurans to estimate building fire contributions in air, surface wipes, and dust samples.

    PubMed

    Pleil, Joachim D; Lorber, Matthew N

    2007-11-01

    The United States Environmental Protection Agency collected ambient air samples in lower Manhattan for about 9 months following the September 11, 2001 World Trade Center (WTC) attacks. Measurements were made of a host of airborne contaminants including volatile organic compounds, polycyclic aromatic hydrocarbons, asbestos, lead, and other contaminants of concern. The present study focuses on the broad class of polychlorinated dibenzo-p-dioxins (CDDs) and dibenzofurans (CDFs) with specific emphasis on the 17 CDD/CDF congeners that exhibit mammalian toxicity. This work is a statistical study comparing the internal patterns of CDD/CDFs using data from an unambiguous fire event (WTC) and other data sets to help identify their sources. A subset of 29 samples all taken between September 16 and October 31, 2001 were treated as a basis set known to be heavily impacted by the WTC building fire source. A second basis set was created using data from Los Angeles and Oakland, CA as published by the California Air Resources Board (CARB) and treated as the archetypical background pattern for CDD/CDFs. The CARB data had a congener profile appearing similar to background air samples from different locations in America and around the world and in different matrices, such as background soils. Such disparate data would normally be interpreted with a qualitative pattern recognition based on congener bar graphs or other forms of factor or cluster analysis that group similar samples together graphically. The procedure developed here employs aspects of those statistical methods to develop a single continuous output variable per sample. Specifically, a form of variance structure-based cluster analysis is used to group congeners within samples to reduce collinearity in the basis sets, new variables are created based on these groups, and multivariate regression is applied to the reduced variable set to determine a predictive equation. This equation predicts a value for an output variable

  19. Determination of sub-part-per-million levels of formaldehyde in air using active or passive sampling on 2,4-dinitrophenylhydrazine-coated glass fiber filters and high-performance liquid chromatography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Levin, J.O.; Andersson, K.; Lindahl, R.

    1985-05-01

    Formaldehyde is sampled from air with the use of a standard miniature glass fiber filter impregnated with 2,4-dinitrophenylhydrazine and phosphoric acid. The formaldehyde hydrazone is desorbed from the filter with acetonitrile and determined by high-performance liquid chromatography using UV detection at 365 nm. Recovery of gas-phase-generated formaldehyde as hydrazone from a 13-mm impregnated filter is 80-100% in the range 0.3-30 ..mu..g of formaldehyde. This corresponds to 0.1-10 mg/m/sup 3/ in a 3-L air sample. When the filter sampling system is used in the active mode, air can be sampled at a rate of up to 1 L/min, affording an overallmore » sensitivity of about 1 ..mu..g/m/sup 3/ based on a 60-L air sample. Results are given from measurements of formaldehyde in indoor air. The DNP-coated filters were also evaluated for passive sampling. In this case 37-mm standard glass fibers were used and the sampling rate was 55-65 mL/min in two types of dosimeters. The diffusion samplers are especially useful for personal exposure monitoring in the work environment. 24 references, 2 figures, 4 tables.« less

  20. Transgenic Zebrafish Reveal Tissue-Specific Differences in Estrogen Signaling in Response to Environmental Water Samples

    PubMed Central

    Iwanowicz, Luke R.; Hung, Alice L.; Blazer, Vicki S.; Halpern, Marnie E.

    2014-01-01

    Background: Environmental endocrine disruptors (EEDs) are exogenous chemicals that mimic endogenous hormones such as estrogens. Previous studies using a zebrafish transgenic reporter demonstrated that the EEDs bisphenol A and genistein preferentially activate estrogen receptors (ERs) in the larval heart compared with the liver. However, it was not known whether the transgenic zebrafish reporter was sensitive enough to detect estrogens from environmental samples, whether environmental estrogens would exhibit tissue-specific effects similar to those of BPA and genistein, or why some compounds preferentially target receptors in the heart. Methods: We tested surface water samples using a transgenic zebrafish reporter with tandem estrogen response elements driving green fluorescent protein expression (5xERE:GFP). Reporter activation was colocalized with tissue-specific expression of ER genes by RNA in situ hybridization. Results: We observed selective patterns of ER activation in transgenic fish exposed to river water samples from the Mid-Atlantic United States, with several samples preferentially activating receptors in embryonic and larval heart valves. We discovered that tissue specificity in ER activation was due to differences in the expression of ER subtypes. ERα was expressed in developing heart valves but not in the liver, whereas ERβ2 had the opposite profile. Accordingly, subtype-specific ER agonists activated the reporter in either the heart valves or the liver. Conclusion: The use of 5xERE:GFP transgenic zebrafish revealed an unexpected tissue-specific difference in the response to environmentally relevant estrogenic compounds. Exposure to estrogenic EEDs in utero was associated with adverse health effects, with the potentially unanticipated consequence of targeting developing heart valves. Citation: Gorelick DA, Iwanowicz LR, Hung AL, Blazer VS, Halpern ME. 2014. Transgenic zebrafish reveal tissue-specific differences in estrogen signaling in response to

  1. Urban air quality assessment using monitoring data of fractionized aerosol samples, chemometrics and meteorological conditions.

    PubMed

    Yotova, Galina I; Tsitouridou, Roxani; Tsakovski, Stefan L; Simeonov, Vasil D

    2016-01-01

    The present article deals with assessment of urban air by using monitoring data for 10 different aerosol fractions (0.015-16 μm) collected at a typical urban site in City of Thessaloniki, Greece. The data set was subject to multivariate statistical analysis (cluster analysis and principal components analysis) and, additionally, to HYSPLIT back trajectory modeling in order to assess in a better way the impact of the weather conditions on the pollution sources identified. A specific element of the study is the effort to clarify the role of outliers in the data set. The reason for the appearance of outliers is strongly related to the atmospheric condition on the particular sampling days leading to enhanced concentration of pollutants (secondary emissions, sea sprays, road and soil dust, combustion processes) especially for ultra fine and coarse particles. It is also shown that three major sources affect the urban air quality of the location studied-sea sprays, mineral dust and anthropogenic influences (agricultural activity, combustion processes, and industrial sources). The level of impact is related to certain extent to the aerosol fraction size. The assessment of the meteorological conditions leads to defining of four downwind patterns affecting the air quality (Pelagic, Western and Central Europe, Eastern and Northeastern Europe and Africa and Southern Europe). Thus, the present study offers a complete urban air assessment taking into account the weather conditions, pollution sources and aerosol fractioning.

  2. Bacterial communities in commercial aircraft high-efficiency particulate air (HEPA) filters assessed by PhyloChip analysis.

    PubMed

    Korves, T M; Piceno, Y M; Tom, L M; Desantis, T Z; Jones, B W; Andersen, G L; Hwang, G M

    2013-02-01

    Air travel can rapidly transport infectious diseases globally. To facilitate the design of biosensors for infectious organisms in commercial aircraft, we characterized bacterial diversity in aircraft air. Samples from 61 aircraft high-efficiency particulate air (HEPA) filters were analyzed with a custom microarray of 16S rRNA gene sequences (PhyloChip), representing bacterial lineages. A total of 606 subfamilies from 41 phyla were detected. The most abundant bacterial subfamilies included bacteria associated with humans, especially skin, gastrointestinal and respiratory tracts, and with water and soil habitats. Operational taxonomic units that contain important human pathogens as well as their close, more benign relatives were detected. When compared to 43 samples of urban outdoor air, aircraft samples differed in composition, with higher relative abundance of Firmicutes and Gammaproteobacteria lineages in aircraft samples, and higher relative abundance of Actinobacteria and Betaproteobacteria lineages in outdoor air samples. In addition, aircraft and outdoor air samples differed in the incidence of taxa containing human pathogens. Overall, these results demonstrate that HEPA filter samples can be used to deeply characterize bacterial diversity in aircraft air and suggest that the presence of close relatives of certain pathogens must be taken into account in probe design for aircraft biosensors. A biosensor that could be deployed in commercial aircraft would be required to function at an extremely low false alarm rate, making an understanding of microbial background important. This study reveals a diverse bacterial background present on aircraft, including bacteria closely related to pathogens of public health concern. Furthermore, this aircraft background is different from outdoor air, suggesting different probes may be needed to detect airborne contaminants to achieve minimal false alarm rates. This study also indicates that aircraft HEPA filters could be used

  3. Evaluation of active sampling strategies for the determination of 1,3-butadiene in air

    NASA Astrophysics Data System (ADS)

    Vallecillos, Laura; Maceira, Alba; Marcé, Rosa Maria; Borrull, Francesc

    2018-03-01

    Two analytical methods for determining levels of 1,3-butadiene in urban and industrial atmospheres were evaluated in this study. Both methods are extensively used for determining the concentration of volatile organic compounds in the atmosphere and involve collecting samples by active adsorptive enrichment on solid sorbents. The first method uses activated charcoal as the sorbent and involves liquid desorption with carbon disulfide. The second involves the use of a multi-sorbent bed with two graphitised carbons and a carbon molecular sieve as the sorbent, with thermal desorption. Special attention was paid to the optimization of the sampling procedure through the study of sample volume, the stability of 1,3-butadiene once inside the sampling tube and the humidity effect. In the end, the thermal desorption method showed better repeatability and limits of detection and quantification for 1,3-butadiene than the liquid desorption method, which makes the thermal desorption method more suitable for analysing air samples from both industrial and urban atmospheres. However, sampling must be performed with a pre-tube filled with a drying agent to prevent the loss of the adsorption capacity of the solid adsorbent caused by water vapour. The thermal desorption method has successfully been applied to determine of 1,3-butadiene inside a 1,3-butadiene production plant and at three locations in the vicinity of the same plant.

  4. Ecotoxicological studies of environmental samples from Buenos Aires area using a standardized amphibian embryo toxicity test (AMPHITOX).

    PubMed

    Herkovits, Jorge; Perez-Coll, Cristina; Herkovits, Francisco D

    2002-01-01

    The toxicity of 34 environmental samples from potentially polluted and reference stations were evaluated by means of the AMPHITOX test from acute to chronic exposure according to the toxicity found in each sample. The samples were obtained from surface and ground water, leaches, industrial effluents and soils. The data, expressed in acute, short-term chronic and chronic Toxicity Units (TUa, TUstc and TUc) resulted in a maximal value of 1000 TUc, found in a leach, while the lower toxicity value was 1.4 TUa corresponding to two surface water samples. In five samples (four providing from reference places) no toxicity was detected. The results point out the possibility of evaluating the toxicity of a wide diversity of samples by means of AMPHITOX as a customized toxicity test. The fact that almost all samples with suspected toxicity in rivers and streams from the Metropolitan area of Buenos Aires city resulted toxic, indicates the need of enhanced stewardship of chemical substances for environmental and human health protection purposes.

  5. Improved Sampling Method Reduces Isokinetic Sampling Errors.

    ERIC Educational Resources Information Center

    Karels, Gale G.

    The particulate sampling system currently in use by the Bay Area Air Pollution Control District, San Francisco, California is described in this presentation for the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971. The method represents a practical, inexpensive tool that can…

  6. Solar Air Sampler

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Nation's first solar-cell-powered air monitoring station was installed at Liberty State Park, New Jersey. Jointly sponsored by state agencies and the Department of Energy, system includes display which describes its operation to park visitors. Unit samples air every sixth day for a period of 24 hours. Air is forced through a glass filter, then is removed each week for examination by the New Jersey Bureau of Air Pollution. During the day, solar cells provide total power for the sampling equipment. Excess energy is stored in a bank of lead-acid batteries for use when needed.

  7. Estimation of sampling error uncertainties in observed surface air temperature change in China

    NASA Astrophysics Data System (ADS)

    Hua, Wei; Shen, Samuel S. P.; Weithmann, Alexander; Wang, Huijun

    2017-08-01

    This study examines the sampling error uncertainties in the monthly surface air temperature (SAT) change in China over recent decades, focusing on the uncertainties of gridded data, national averages, and linear trends. Results indicate that large sampling error variances appear at the station-sparse area of northern and western China with the maximum value exceeding 2.0 K2 while small sampling error variances are found at the station-dense area of southern and eastern China with most grid values being less than 0.05 K2. In general, the negative temperature existed in each month prior to the 1980s, and a warming in temperature began thereafter, which accelerated in the early and mid-1990s. The increasing trend in the SAT series was observed for each month of the year with the largest temperature increase and highest uncertainty of 0.51 ± 0.29 K (10 year)-1 occurring in February and the weakest trend and smallest uncertainty of 0.13 ± 0.07 K (10 year)-1 in August. The sampling error uncertainties in the national average annual mean SAT series are not sufficiently large to alter the conclusion of the persistent warming in China. In addition, the sampling error uncertainties in the SAT series show a clear variation compared with other uncertainty estimation methods, which is a plausible reason for the inconsistent variations between our estimate and other studies during this period.

  8. Metagenomic analysis of Sichuan takin fecal sample viromes reveals novel enterovirus and astrovirus.

    PubMed

    Guan, Tian-Pei; Teng, Jade L L; Yeong, Kai-Yan; You, Zhang-Qiang; Liu, Hao; Wong, Samson S Y; Lau, Susanna K P; Woo, Patrick C Y

    2018-06-07

    The Sichuan takin inhabits the bamboo forests in the Eastern Himalayas and is considered as a national treasure of China with the highest legal protection and conservation status considered as vulnerable according to The IUCN Red List of Threatened Species. In this study, fecal samples of 71 Sichuan takins were pooled and deep sequenced. Among the 103,553 viral sequences, 21,961 were assigned to mammalian viruses. De novo assembly revealed genomes of an enterovirus and an astrovirus and contigs of circoviruses and genogroup I picobirnaviruses. Complete genome sequencing and phylogenetic analysis showed that Sichuan takin enterovirus is a novel serotype/genotype of the species Enterovirus G, with evidence of recombination. Sichuan takin astrovirus is a new subtype of bovine astrovirus, probably belonging to a new genogroup in the genus Mamastrovirus. Further studies will reveal whether these viruses can also be found in Mishmi takin and Shaanxi takin and their pathogenic potentials. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Laboratory Development of a Passive Sampling Device for Hydrazines in Ambient Air

    DTIC Science & Technology

    1990-05-30

    of dilution air . Conditioned house- compressed air is used as the diluent. The conditioning procedure consists of passing the house air through a...Device N4 for Hydrazines in Ambient Air P. A. TAFFE,* K. P. CROSSMAN,* S. L. ROSE-PEHRSSON, AND J. R. WYATT 0 Chemistry Dynamics and Diagnostic Branch...Ambient Air 6. AUTHOR(S) Taffe,* P. A., Crossman,* K. P., Wyatt, J. R., and Rose-Pehrsson, S. L. 7. PERFORMING ORGANIZATION NAME(S) AND ADORESS(ES) 8

  10. Early detection of foot-and-mouth disease virus from infected cattle using a dry filter air sampling system

    USDA-ARS?s Scientific Manuscript database

    Foot-and-mouth disease (FMD) is a highly contagious livestock disease of high economic impact. Early detection of FMD virus (FMDV) is fundamental for rapid outbreak control. Air sampling collection has been demonstrated as a useful technique for detection of FMDV RNA in infected animals, related to ...

  11. NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR EXTRACTION OF AIR SAMPLES FOR GC/MS ANALYSIS OF PESTICIDES (BCO-L-11.0)

    EPA Science Inventory

    The purpose of this SOP is to describe the procedures for extracting and preparing an air sample consisting of a polyurethane foam (PUF) plug and Teflon-coated glass fiber filter (Pallflex T60A20) for analysis of pesticides. This procedure covers sample preparation for samples t...

  12. Assessment of Air Quality in the Shuttle and International Space Station (ISS) Based on Samples Returned by STS-100 at the Conclusion of 6A

    NASA Technical Reports Server (NTRS)

    James, John T.

    2001-01-01

    The toxicological assessment of air samples returned at the end of the STS-100 (6A) flight to the ISS is reported. ISS air samples were taken in March and April 2001 from the Service Module, FGB, and U.S. Laboratory using grab sample canisters (GSCs) and/or formaldehyde badges. An unplanned "first-entry" sample of the MPLM2 (multipurpose logistics module) atmosphere was taken with a GSC, and preflight and end-of-mission samples were obtained from Endeavour using GSCs. Analytical methods have not changed from earlier reports, and all quality control measures were met for the data presented herein. The two general criteria used to assess air quality are the total-non-methane-volatile organic hydrocarbons (NMVOCs) and the total T-value (minus the CO2 and formaldehyde contribution). Because of the Freon 218 (octafluoropropane, OFP) leak, its contribution to the NMVOC is indicated in brackets. When comparing the NMVOC values with the 25 mg/cubic m guideline, the OFP contributions should be subtracted. Control of atmospheric alcohols is important to the water recovery system engineers, hence total alcohols were also assessed in each sample.

  13. Infrequent air contamination with Acinetobacter baumannii of air surrounding known colonized or infected patients.

    PubMed

    Rock, Clare; Harris, Anthony D; Johnson, J Kristie; Bischoff, Werner E; Thom, Kerri A

    2015-07-01

    Using a validated air sampling method we found Acinetobacter baumannii in the air surrounding only 1 of 12 patients known to be colonized or infected with A. baumannii. Patients' closed-circuit ventilator status, frequent air exchanges in patient rooms, and short sampling time may have contributed to this low burden.

  14. Radiological Air Sampling. Protocol Development for the Canadian Forces

    DTIC Science & Technology

    2003-03-01

    samplers trap these airborne radon daughters . Because radon is ubiquitous, all air samplers will catch these radioactive radon daughters in the...environment is complicated because all air sampler filters are radioactive because of the radon daughters . ’Actually, D will often depend on the isotope that...simply as "radon". 2 DRDC Ottawa TM 2003-149 -28 - 22 R_ 211p0 214pb 3.8 d 3.0 m 27 m 214Bi 210TI Radon Daughters 20 m ŕ.3 m (Uranium Decay Chain

  15. Biomimetic air sampling for detection of low concentrations of molecules and bioagents : LDRD 52744 final report.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hughes, Robert Clark

    2003-12-01

    Present methods of air sampling for low concentrations of chemicals like explosives and bioagents involve noisy and power hungry collectors with mechanical parts for moving large volumes of air. However there are biological systems that are capable of detecting very low concentrations of molecules with no mechanical moving parts. An example is the silkworm moth antenna which is a highly branched structure where each of 100 branches contains about 200 sensory 'hairs' which have dimensions of 2 microns wide by 100 microns long. The hairs contain about 3000 pores which is where the gas phase molecules enter the aqueous (lymph)more » phase for detection. Simulations of diffusion of molecules indicate that this 'forest' of hairs is 'designed' to maximize the extraction of the vapor phase molecules. Since typical molecules lose about 4 decades in diffusion constant upon entering the liquid phase, it is important to allow air diffusion to bring the molecule as close to the 'sensor' as possible. The moth acts on concentrations as low as 1000 molecules per cubic cm. (one part in 1e16). A 3-D collection system of these dimensions could be fabricated by micromachining techniques available at Sandia. This LDRD addresses the issues involved with extracting molecules from air onto micromachined structures and then delivering those molecules to microsensors for detection.« less

  16. Evaluation of sample recovery of malodorous livestock gases from air sampling bags, solid-phase microextraction fibers, Tenax TA sorbent tubes, and sampling canisters.

    PubMed

    Koziel, Jacek A; Spinhirne, Jarett P; Lloyd, Jenny D; Parker, David B; Wright, Donald W; Kuhrt, Fred W

    2005-08-01

    Odorous gases associated with livestock operations are complex mixtures of hundreds if not thousands of compounds. Research is needed to know how best to sample and analyze these compounds. The main objective of this research was to compare recoveries of a standard gas mixture of 11 odorous compounds from the Carboxen/PDMS 75-microm solid-phase microextraction fibers, polyvinyl fluoride (PVF; Tedlar), fluorinated ethylene propylene copolymer (FEP; Teflon), foil, and polyethylene terephthalate (PET; Melinex) air sampling bags, sorbent 2,b-diphenylene-oxide polymer resin (Tenax TA) tubes, and standard 6-L Stabilizer sampling canisters after sample storage for 0.5, 24, and 120 (for sorbent tubes only) hrs at room temperature. The standard gas mixture consisted of 7 volatile fatty acids (VFAs) from acetic to hexanoic, and 4 semivolatile organic compounds including p-cresol, indole, 4-ethylphenol, and 2'-aminoacetophenone with concentrations ranging from 5.1 ppb for indole to 1270 ppb for acetic acid. On average, SPME had the highest mean recovery for all 11 gases of 106.2%, and 98.3% for 0.5- and 24-hr sample storage time, respectively. This was followed by the Tenax TA sorbent tubes (94.8% and 88.3%) for 24 and 120 hr, respectively; PET bags (71.7% and 47.2%), FEP bags (75.4% and 39.4%), commercial Tedlar bags (67.6% and 22.7%), in-house-made Tedlar bags (47.3% and 37.4%), foil bags (16.4% and 4.3%), and canisters (4.2% and 0.5%), for 0.5 and 24 hr, respectively. VFAs had higher recoveries than semivolatile organic compounds for all of the bags and canisters. New FEP bags and new foil bags had the lowest and the highest amounts of chemical impurities, respectively. New commercial Tedlar bags had measurable concentrations of N,N-dimethyl acetamide and phenol. Foil bags had measurable concentrations of acetic, propionic, butyric, valeric, and hexanoic acids.

  17. Extensive Viable Middle East Respiratory Syndrome (MERS) Coronavirus Contamination in Air and Surrounding Environment in MERS Isolation Wards.

    PubMed

    Kim, Sung-Han; Chang, So Young; Sung, Minki; Park, Ji Hoon; Bin Kim, Hong; Lee, Heeyoung; Choi, Jae-Phil; Choi, Won Suk; Min, Ji-Young

    2016-08-01

    The largest outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) outside the Middle East occurred in South Korea in 2015 and resulted in 186 laboratory-confirmed infections, including 36 (19%) deaths. Some hospitals were considered epicenters of infection and voluntarily shut down most of their operations after nearly half of all transmissions occurred in hospital settings. However, the ways that MERS-CoV is transmitted in healthcare settings are not well defined. We explored the possible contribution of contaminated hospital air and surfaces to MERS transmission by collecting air and swabbing environmental surfaces in 2 hospitals treating MERS-CoV patients. The samples were tested by viral culture with reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence assay (IFA) using MERS-CoV Spike antibody, and electron microscopy (EM). The presence of MERS-CoV was confirmed by RT-PCR of viral cultures of 4 of 7 air samples from 2 patients' rooms, 1 patient's restroom, and 1 common corridor. In addition, MERS-CoV was detected in 15 of 68 surface swabs by viral cultures. IFA on the cultures of the air and swab samples revealed the presence of MERS-CoV. EM images also revealed intact particles of MERS-CoV in viral cultures of the air and swab samples. These data provide experimental evidence for extensive viable MERS-CoV contamination of the air and surrounding materials in MERS outbreak units. Thus, our findings call for epidemiologic investigation of the possible scenarios for contact and airborne transmission, and raise concern regarding the adequacy of current infection control procedures. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  18. A novel personal air sampling device for collecting volatile organic compounds: a comparison to charcoal tubes and diffusive badges.

    PubMed

    Rossner, Alan; Farant, Jean-Pierre

    2004-02-01

    Evacuated canisters have been used for many years to collect ambient air samples for gases and vapors. Recently, significant interest has arisen in using evacuated canisters for personal breathing zone sampling as an alternative to sorbent sampling. A novel flow control device was designed and built at McGill University. The flow control device was designed to provide a very low flow rate, <0.5 mL/min, to allow a sample to be collected over an extended period of time. Previous experiments run at McGill have shown agreement between the mathematical and empirical models to predict flow rate. The flow control device combined with an evacuated canister (capillary flow control-canister) was used in a series of experiments to evaluate its performance against charcoal tubes and diffusive badges. Air samples of six volatile organic compounds were simultaneously collected in a chamber using the capillary flow control-canister, charcoal tubes, and diffusive badges. Five different concentrations of the six volatile organic compounds were evaluated. The results from the three sampling devices were compared to each other and to concentration values obtained using an online gas chromatograph (GC). Eighty-four samples of each method were collected for each of the six chemicals. Results indicate that the capillary flow control-canister device compares quite favorably to the online GC and to the charcoal tubes, p > 0.05 for most of the tests. The capillary flow control-canister was found to be more accurate for the compounds evaluated, easier to use, and easier to analyze than charcoal tubes and passive dosimeter badges.

  19. Solid-phase microextraction fiber development for sampling and analysis of volatile organohalogen compounds in air.

    PubMed

    Attari, Seyed Ghavameddin; Bahrami, Abdolrahman; Shahna, Farshid Ghorbani; Heidari, Mahmoud

    2014-01-01

    A green, environmental friendly and sensitive method for determination of volatile organohalogen compounds was described in this paper. The method is based on a homemade sol-gel single-walled carbon nanotube/silica composite coated solid-phase microextraction to develop for sampling and analysis of Carbon tetrachloride, Benzotrichloride, Chloromethyl methyl ether and Trichloroethylene in air. Application of this method was investigated under different laboratory conditions. Predetermined concentrations of each analytes were prepared in a home-made standard chamber and the influences of experimental parameters such as temperature, humidity, extraction time, storage time, desorption temperature, desorption time and the sorbent performance were investigated. Under optimal conditions, the use of single-walled carbon nanotube/silica composite fiber showed good performance, high sensitive and fast sampling of volatile organohalogen compounds from air. For linearity test the regression correlation coefficient was more than 98% for analyte of interest and linear dynamic range for the proposed fiber and the applied Gas Chromatography-Flame Ionization Detector technique was from 1 to 100 ngmL(-1). Method detection limits ranged between 0.09 to 0.2 ngmL(-1) and method quantification limits were between 0.25 and 0.7 ngmL(-1). Single-walled carbon nanotube/silica composite fiber was highly reproducible, relative standard deviations were between 4.3 to 11.7 percent.

  20. Atmospheric Carbon Monoxide Mixing Ratios NOAA Climate Monitoring and Diagnostics Laboratory Cooperative Air Sampling Network (1988-1993) (DB1011)

    DOE Data Explorer

    Novelli, P. C.; Masarie, K. A.

    1994-01-01

    Individual site files provide CO mixing ratios in parts per billion (ppb) (ppb = parts in 109 by mole fraction) based on measurements from the NOAA/CMDL Cooperative Air Sampling Network beginning 1988. Data are provided through June 1993 for stations at which the first sample was collected before July 1991. All samples were analyzed for CO at the NOAA/CMDL laboratory in Boulder by gas chromatography with mercuric oxide reduction detection, and all measurements are referenced to the CMDL CO scale (Novelli et al., 1991, Novelli et al., 1994).

  1. Odour-causing compounds in air samples: gas-liquid partition coefficients and determination using solid-phase microextraction and GC with mass spectrometric detection.

    PubMed

    Godayol, Anna; Alonso, Mònica; Sanchez, Juan M; Anticó, Enriqueta

    2013-03-01

    A quantification method based on solid-phase microextraction followed by GC coupled to MS was developed for the determination of gas-liquid partition coefficients and for the air monitoring of a group of odour-causing compounds that had previously been found in wastewater samples including dimethyl disulphide, phenol, indole, skatole, octanal, nonanal, benzothiazole and some terpenes. Using a divinylbenzene/carboxen/polydimethylsiloxane fibre, adsorption kinetics have been studied to define an extraction time that would avoid coating saturation. It was found that for an extraction time of 10 min, external calibration could be performed in the range of 0.4-100 μg/m(3), with detection limits between 0.1 and 20 μg/m(3). Inter-day precision of the developed method was evaluated (n = 5) and RSD values between 12 and 24% were obtained for all compounds. The proposed method has been applied to the analysis of air samples surrounding a wastewater treatment plant in Catalonia (Spain). In all air samples evaluated, dimethyl disulphide, limonene and phenol were detected, and the first two were the compounds that showed the highest partition coefficients. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Integrated sampling and analysis unit for the determination of sexual pheromones in environmental air using fabric phase sorptive extraction and headspace-gas chromatography-mass spectrometry.

    PubMed

    Alcudia-León, M Carmen; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel; Kabir, Abuzar; Furton, Kenneth G

    2017-03-10

    This article presents a novel unit that integrates for the first time air sampling and preconcentration based on the use of fabric phase sorptive extraction principles. The determination of Tuta absoluta sexual pheromone traces in environmental air has been selected as analytical problem. For this aim, a novel laboratory-built unit made up of commercial brass elements as holder of the sol-gel coated fabric extracting phase has been designed and optimized. The performance of the integrated unit was evaluated analyzing environmental air sampled in tomato crops. The unit can work under sampling and analysis mode which eliminates any need for sorptive phase manipulation prior to instrumental analysis. In the sampling mode, the unit can be connected to a sampling pump to pass the air through the sorptive phase at a controlled flow-rate. In the analysis mode, it is placed in the gas chromatograph autosampler without any instrumental modification. It also diminishes the risk of cross contamination between sampling and analysis. The performance of the new unit has been evaluated using the main components of the sexual pheromone of Tuta absoluta [(3E,8Z,11Z)-tetradecatrien-1-yl acetate and (3E,8Z)-tetradecadien-1-yl acetate] as model analytes. The limits of detection for both compounds resulted to be 1.6μg and 0.8μg, respectively, while the precision (expressed as relative standard deviation) was better than 3.7%. Finally, the unit has been deployed in the field to analyze a number of real life samples, some of them were found positive. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Canine epidermal lipid sampling by skin scrub revealed variations between different body sites and normal and atopic dogs

    PubMed Central

    2014-01-01

    Background Previously, we evaluated a minimally invasive epidermal lipid sampling method called skin scrub, which achieved reproducible and comparable results to skin scraping. The present study aimed at investigating regional variations in canine epidermal lipid composition using the skin scrub technique and its suitability for collecting skin lipids in dogs suffering from certain skin diseases. Eight different body sites (5 highly and 3 lowly predisposed for atopic lesions) were sampled by skin scrub in 8 control dogs with normal skin. Additionally, lesional and non-lesional skin was sampled from 12 atopic dogs and 4 dogs with other skin diseases by skin scrub. Lipid fractions were separated by high performance thin layer chromatography and analysed densitometrically. Results No significant differences in total lipid content were found among the body sites tested in the control dogs. However, the pinna, lip and caudal back contained significantly lower concentrations of ceramides, whereas the palmar metacarpus and the axillary region contained significantly higher amounts of ceramides and cholesterol than most other body sites. The amount of total lipids and ceramides including all ceramide classes were significantly lower in both lesional and non-lesional skin of atopic dogs compared to normal skin, with the reduction being more pronounced in lesional skin. The sampling by skin scrub was relatively painless and caused only slight erythema at the sampled areas but no oedema. Histological examinations of skin biopsies at 2 skin scrubbed areas revealed a potential lipid extraction from the transition zone between stratum corneum and granulosum. Conclusions The present study revealed regional variations in the epidermal lipid and ceramide composition in dogs without skin abnormalities but no connection between lipid composition and predilection sites for canine atopic dermatitis lesions. The skin scrub technique proved to be a practicable sampling method for canine

  4. Characterization of the bacterial and fungal microbiome in indoor dust and outdoor air samples: a pilot study.

    PubMed

    Hanson, Blake; Zhou, Yanjiao; Bautista, Eddy J; Urch, Bruce; Speck, Mary; Silverman, Frances; Muilenberg, Michael; Phipatanakul, Wanda; Weinstock, George; Sodergren, Erica; Gold, Diane R; Sordillo, Joanne E

    2016-06-15

    Environmental microbes have been associated with both protective and adverse health effects in children and adults. Epidemiological studies often rely on broad biomarkers of microbial exposure (i.e. endotoxin, 1 → 3-beta-d-glucan), but fail to identify the taxonomic composition of the microbial community. Our aim was to characterize the bacterial and fungal microbiome in different types of environmental samples collected in studies of human health effects. We determined the composition of microbial communities present in home, school and outdoor air samples by amplifying and sequencing regions of rRNA genes from bacteria (16S) and fungi (18S and ITS). Samples for this pilot study included indoor settled dust (from both a Boston area birth cohort study on Home Allergens and Asthma (HAA) (n = 12) and a study of school exposures and asthma symptoms (SICAS) (n = 1)), as well as fine and coarse concentrated outdoor ambient particulate (CAP) samples (n = 9). Sequencing of amplified 16S, 18S, and ITS regions was performed on the Roche-454 Life Sciences Titanium pyrosequencing platform. Indoor dust samples were dominated by Gram-positive bacteria (Firmicutes and Actinobacteria); the most abundant bacterial genera were those related to human flora (Streptococcus, Staphylococcus, Corynebacterium and Lactobacillus). Outdoor CAPs were dominated by Gram-negative Proteobacteria from water and soil sources, in particular the genera Acidovorax, and Brevundimonas (which were present at very low levels or entirely absent in indoor dust). Phylum-level fungal distributions identified by 18S or ITS regions showed very similar findings: a predominance of Ascomycota in indoor dust and Basidiomycota in outdoor CAPs. ITS sequencing of fungal genera in indoor dust showed significant proportions of Aureobasidium and Leptosphaerulina along with some contribution from Cryptococcus, Epicoccum, Aspergillus and the human commensal Malassezia. ITS sequencing detected more than 70 fungal genera

  5. Continuous multichannel monitoring of cave air carbon dioxide using a pumped non-dispersive infrared analyser

    NASA Astrophysics Data System (ADS)

    Mattey, D.

    2012-04-01

    The concentration of CO2 in cave air is one of the main controls on the rate of degassing of dripwater and on the kinetics of calcite precipitation forming speleothem deposits. Measurements of cave air CO2reveal great complexity in the spatial distribution among interconnected cave chambers and temporal changes on synoptic to seasonal time scales. The rock of Gibraltar hosts a large number of caves distributed over a 300 meter range in altitude and monthly sampling and analysis of air and water combined with continuous logging of temperature, humidity and drip discharge rates since 2004 reveals the importance of density-driven seasonal ventilation which drives large-scale advection of CO2-rich air though the cave systems. Since 2008 we have deployed automatic CO2 monitoring systems that regularly sample cave air from up to 8 locations distributed laterally and vertically in St Michaels Cave located near the top of the rock at 275m asl and Ragged Staff Cave located in the heart of the rock near sea level. The logging system is controlled by a Campbell Scientific CR1000 programmable datalogger which controls an 8 port manifold connected to sampling lines leading to different parts of the cave over a distance of up to 250 meters. The manifold is pumped at a rate of 5l per minute drawing air through 6mm or 8mm id polythene tubing via a 1m Nafion loop to reduce humidity to local ambient conditions. The outlet of the primary pump leads to an open split which is sampled by a second low flow pump which delivers air at 100ml/minute to a Licor 820 CO2 analyser. The software selects the port to be sampled, flushes the line for 2 minutes and CO2 analysed as a set of 5 measurements averaged over 10 second intervals. The system then switches to the next port and when complete shuts down to conserve power after using 20 watts over a 30 minute period of analysis. In the absence of local mains power (eg from the show cave lighting system) two 12v car batteries will power the system

  6. Development of one-step hollow fiber supported liquid phase sampling technique for occupational workplace air analysis using high performance liquid chromatography with ultra-violet detector.

    PubMed

    Yan, Cheing-Tong; Chien, Hai-Ying

    2012-07-13

    In this study, a simple and novel one-step hollow-fiber supported liquid-phase sampling (HF-LPS) technique was developed for enriched sampling of gaseous toxic species prior to chemical analysis for workplace air monitoring. A lab-made apparatus designed with a gaseous sample generator and a microdialysis sampling cavity (for HF-LPS) was utilized and evaluated to simulate gaseous contaminant air for occupational workplace analysis. Gaseous phenol was selected as the model toxic species. A polyethersulfone hollow fiber dialysis module filled with ethylene glycol in the shell-side was applied as the absorption solvent to collect phenol from a gas flow through the tube-side, based on the concentration distribution of phenol between the absorption solvent and the gas flow. After sampling, 20 μL of the extractant was analyzed by high performance liquid chromatography with ultraviolet detection (HPLC-UV). Factors that influence the generation of gaseous standards and the HF-LPS were studied thoroughly. Results indicated that at 25 °C the phenol (2000 μg/mL) standard solution injected at 15-μL/min can be vaporized into sampling cavity under nitrogen flow at 780 mL/min, to generate gaseous phenol with concentration approximate to twice the permissible exposure limit. Sampling at 37.3 mL/min for 30 min can meet the requirement of the workplace air monitoring. The phenol in air ranged between 0.7 and 10 cm³/m³ (shows excellent linearity) with recovery between 98.1 and 104.1%. The proposed method was identified as a one-step sampling for workplace monitoring with advantages of convenience, rapidity, sensitivity, and usage of less-toxic solvent. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Air-sea interaction regimes in the sub-Antarctic Southern Ocean and Antarctic marginal ice zone revealed by icebreaker measurements

    NASA Astrophysics Data System (ADS)

    Yu, Lisan; Jin, Xiangze; Schulz, Eric W.; Josey, Simon A.

    2017-08-01

    This study analyzed shipboard air-sea measurements acquired by the icebreaker Aurora Australis during its off-winter operation in December 2010 to May 2012. Mean conditions over 7 months (October-April) were compiled from a total of 22 ship tracks. The icebreaker traversed the water between Hobart, Tasmania, and the Antarctic continent, providing valuable in situ insight into two dynamically important, yet poorly sampled, regimes: the sub-Antarctic Southern Ocean and the Antarctic marginal ice zone (MIZ) in the Indian Ocean sector. The transition from the open water to the ice-covered surface creates sharp changes in albedo, surface roughness, and air temperature, leading to consequential effects on air-sea variables and fluxes. Major effort was made to estimate the air-sea fluxes in the MIZ using the bulk flux algorithms that are tuned specifically for the sea-ice effects, while computing the fluxes over the sub-Antarctic section using the COARE3.0 algorithm. The study evidenced strong sea-ice modulations on winds, with the southerly airflow showing deceleration (convergence) in the MIZ and acceleration (divergence) when moving away from the MIZ. Marked seasonal variations in heat exchanges between the atmosphere and the ice margin were noted. The monotonic increase in turbulent latent and sensible heat fluxes after summer turned the MIZ quickly into a heat loss regime, while at the same time the sub-Antarctic surface water continued to receive heat from the atmosphere. The drastic increase in turbulent heat loss in the MIZ contrasted sharply to the nonsignificant and seasonally invariant turbulent heat loss over the sub-Antarctic open water.Plain Language SummaryThe icebreaker Aurora Australis is a research and supply vessel that is regularly chartered by the Australian Antarctic Division during the southern summer to operate in waters between Hobart, Tasmania, and Antarctica. The vessel serves as the main lifeline to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15279352','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15279352"><span>Microbial <span class="hlt">air</span> quality in mass transport buses and work-related illness among bus drivers of Bangkok Mass Transit Authority.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luksamijarulkul, Pipat; Sundhiyodhin, Viboonsri; Luksamijarulkul, Soavalug; Kaewboonchoo, Orawan</p> <p>2004-06-01</p> <p>The <span class="hlt">air</span> quality in mass transport buses, especially <span class="hlt">air</span>-conditioned buses may affect bus drivers who work full time. Bus numbers 16, 63, 67 and 166 of the Seventh Bus Zone of Bangkok Mass Transit Authority were randomly selected to investigate for microbial <span class="hlt">air</span> quality. Nine <span class="hlt">air</span>-conditioned buses and 2-4 open-<span class="hlt">air</span> buses for each number of the bus (36 <span class="hlt">air</span>-conditioned buses and 12 open-<span class="hlt">air</span> buses) were included. Five points of in-bus <span class="hlt">air</span> <span class="hlt">samples</span> in each studied bus were collected by using the Millipore A ir Tester Totally, 180 and 60 <span class="hlt">air</span> <span class="hlt">samples</span> collected from <span class="hlt">air</span>-conditioned buses and open-<span class="hlt">air</span> buses were cultured for bacterial and fungal counts. The bus drivers who drove the studied buses were interviewed towards histories of work-related illness while working. The results <span class="hlt">revealed</span> that the mean +/- SD of bacterial counts in the studied open-<span class="hlt">air</span> buses ranged from 358.50 +/- 146.66 CFU/m3 to 506 +/- 137.62 CFU/m3; bus number 16 had the highest level. As well as the mean +/- SD of fungal counts which ranged from 93.33 +/- 44.83 CFU/m3 to 302 +/- 294.65 CFU/m3; bus number 166 had the highest level. Whereas, the mean +/- SD of bacterial counts in the studied <span class="hlt">air</span>-conditioned buses ranged from 115.24 +/- 136.01 CFU/m3 to 244.69 +/- 234.85 CFU/m3; bus numbers 16 and 67 had the highest level. As well as the mean +/- SD of fungal counts which rangedfrom 18.84 +/- 39.42 CFU/m3 to 96.13 +/- 234.76 CFU/m3; bus number 166 had the highest level. When 180 and 60 studied <span class="hlt">air</span> <span class="hlt">samples</span> were analyzed in detail, it was found that 33.33% of the <span class="hlt">air</span> <span class="hlt">samples</span> from open-<span class="hlt">air</span> buses and 6.11% of <span class="hlt">air</span> <span class="hlt">samples</span> from <span class="hlt">air</span>-conditioned buses had a high level of bacterial counts (> 500 CFU/m3) while 6.67% of <span class="hlt">air</span> <span class="hlt">samples</span> from open-<span class="hlt">air</span> buses and 2.78% of <span class="hlt">air</span> <span class="hlt">samples</span> from <span class="hlt">air</span>-conditioned buses had a high level of fungal counts (> 500 CFU/m3). Data from the history of work-related illnesses among the studied bus drivers showed that 91.67% of open-<span class="hlt">air</span> bus drivers and 57.28% of <span class="hlt">air</span>-conditioned bus drivers had</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9318071','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9318071"><span>PERIODIC <span class="hlt">AIR</span>-BREATHING BEHAVIOUR IN A PRIMITIVE FISH <span class="hlt">REVEALED</span> BY SPECTRAL ANALYSIS</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hedrick; Katz; Jones</p> <p>1994-12-01</p> <p>The ventilatory patterns of <span class="hlt">air</span>-breathing fish are commonly described as 'arrhythmic' or 'irregular' because the variable periods of breath-holding are punctuated by seemingly unpredictable <span class="hlt">air</span>-breathing events (see Shelton et al. 1986). This apparent arrhythmicity contrasts with the perceived periodism or regularity in the gill ventilation patterns of some fish and with lung ventilation in birds and mammals. In this sense, periodism refers to behaviour that occurs with a definite, recurring interval (Bendat and Piersol, 1986). The characterisation of aerial ventilation patterns in fish as 'aperiodic' has been generally accepted on the basis of qualitative examination and it remains to be validated with rigorous testing. The bowfin, Amia calva (L.), is a primitive <span class="hlt">air</span>-breathing fish that makes intermittent excursions to the <span class="hlt">air</span>­water interface to gulp <span class="hlt">air</span>, which is transferred to its well-vascularized gas bladder. Its phylogenetic position as the only extant member of the sister lineage of modern teleosts affords a unique opportunity to examine the evolution of aerial ventilation and provides a model for the examination of ventilatory patterns in primitive fishes. To establish whether Amia calva exhibit a particular pattern of <span class="hlt">air</span>-breathing, we examined time series records of aerial ventilations from undisturbed fish over long periods (8 h). These records were the same as those used to calculate average ventilation intervals under a variety of experimental conditions (Hedrick and Jones, 1993). Their study also reported the occurrence of two distinct breath types. Type I breaths were characterised by an exhalation followed by an inhalation, whereas type II breaths were characterised by inhalation only. It was also hypothesized that the type I breaths were employed to meet oxygen demands, whereas the type II breaths were used to regulate gas bladder volume. However, they did not investigate the potential presence of a periodic ventilatory pattern. We now report</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A22A..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A22A..05L"><span>Globalizing <span class="hlt">Air</span> Pollution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, J.</p> <p>2017-12-01</p> <p>Recent studies have <span class="hlt">revealed</span> the issue of globalizing <span class="hlt">air</span> pollution through complex coupling of atmospheric transport (physical route) and economic trade (socioeconomic route). Recognition of such globalizing <span class="hlt">air</span> pollution has important implications for understanding the impacts of regional and global consumption (of goods and services) on <span class="hlt">air</span> quality, public health, climate and the ecosystems. And addressing these questions often requires improved modeling, measurements and economic-emission statistics. This talk will introduce the concept and mechanism of globalizing <span class="hlt">air</span> pollution, with following demonstrations based on recent works on modeling, satellite measurement and multi-disciplinary assessment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26490943','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26490943"><span>Characterizing <span class="hlt">air</span> quality data from complex network perspective.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fan, Xinghua; Wang, Li; Xu, Huihui; Li, Shasha; Tian, Lixin</p> <p>2016-02-01</p> <p><span class="hlt">Air</span> quality depends mainly on changes in emission of pollutants and their precursors. Understanding its characteristics is the key to predicting and controlling <span class="hlt">air</span> quality. In this study, complex networks were built to analyze topological characteristics of <span class="hlt">air</span> quality data by correlation coefficient method. Firstly, PM2.5 (particulate matter with aerodynamic diameter less than 2.5 μm) indexes of eight monitoring sites in Beijing were selected as <span class="hlt">samples</span> from January 2013 to December 2014. Secondly, the C-C method was applied to determine the structure of phase space. Points in the reconstructed phase space were considered to be nodes of the network mapped. Then, edges were determined by nodes having the correlation greater than a critical threshold. Three properties of the constructed networks, degree distribution, clustering coefficient, and modularity, were used to determine the optimal value of the critical threshold. Finally, by analyzing and comparing topological properties, we pointed out that similarities and difference in the constructed complex networks <span class="hlt">revealed</span> influence factors and their different roles on real <span class="hlt">air</span> quality system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28557779','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28557779"><span>Adventures in the Environmental World and Environmental Microbiology <span class="hlt">Sampling</span> of <span class="hlt">Air</span> for Pharmaceutical Sterile Compounding.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ligugnana, Roberto</p> <p>2017-01-01</p> <p>Chapter <797> issued by the United States Pharmacopeial Convention, Inc. is the standard for sterile compounding. It is designed to reduce the number of patient infections due to contaminated pharmaceutical preparation. This regulation applies to all staff who prepare compounded sterile preparations and all places where they are produced, including hospitals, clinics, pharmacies, and physician's offices. This article provides the history of environmental microbiology and provides a discussion on environmental microbiology <span class="hlt">sampling</span> of <span class="hlt">air</span> for pharmaceutical sterile compounding. Copyright© by International Journal of Pharmaceutical Compounding, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110020794','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110020794"><span>STS 134, 135 and 26S Return <span class="hlt">Samples</span>: <span class="hlt">Air</span> Quality aboard Shuttle (STS-134) and International Space Station</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>James, John T.</p> <p>2011-01-01</p> <p>This is a very limited set of <span class="hlt">samples</span> on which to perform an <span class="hlt">air</span> quality assessment. However, based on these <span class="hlt">samples</span>, we have no reason to believe that nominal ISS <span class="hlt">air</span> is unsafe to breathe. We must continue to be vigilant when dealing with nominal atmospheres in ISS. New, unmanned modules require special attention when the crew first enters. Carbon Monoxide Accumulation aboard ISS: Beginning in late 2008 the nominal concentrations of CO began increasing gradually (Figure 1). The results from <span class="hlt">samples</span> returned on this flight indicate that the CO concentrations, after dropping in late 2009, have cycled upward and then settled back to concentrations near 2 mg/m3. In any case, these changes are well below the 180-day SMAC for CO, which is17 mg/m3. There is no threat to crew health. Carbon Dioxide: This anthropogenic compound has drawn much attention recently because of the possibility that it could contribute to the effects of intracranial hypertension experienced because of spaceflight-induced fluid shifts. From now on we will maintain a plot (Figure 2) of carbon dioxide concentrations ( SD) by averaging the values found in the 3-5 mini-GSC <span class="hlt">samples</span> taken each month in diverse locations of the ISS. This will enable us to estimate the average exposure of crewmembers to carbon dioxide during their stay aboard the ISS. In general, concentrations are being maintained below 3.5 mmHg. Figure 1</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860018341&hterms=kubo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dkubo','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860018341&hterms=kubo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dkubo"><span>Measurements of concentrations of chlorofluoromethanes (CFMs) carbon dioxide and carbon isotope ratio in stratospheric and tropospheric <span class="hlt">air</span> by grab-<span class="hlt">sampling</span> systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Itoh, T.; Kubo, H.; Honda, H.; Tominaga, T.; Makide, Y.; Yakohata, A.; Sakai, H.</p> <p>1985-01-01</p> <p>Measurements of concentrations of chlorofluoromethanes (CFMs), carbon dioxide and carbon isotope ratio in stratospheric and tropospheric <span class="hlt">air</span> by grab-<span class="hlt">sampling</span> systems are reported. The balloon-borne grab-<span class="hlt">sampling</span> system has been launched from Sanriku Balloon Center three times since 1981. It consists of: (1) six <span class="hlt">sampling</span> cylinders, (2) eight motor driven values, (3) control and monitor circuits, and (4) pressurized housing. Particular consideration is paid to the problem of contamination. Strict requirements are placed on the choice of materials and components, construction methods, cleaning techniques, vacuum integrity, and <span class="hlt">sampling</span> procedures. An aluminum pressurized housing and a 4-m long inlet line are employed to prevent the <span class="hlt">sampling</span> <span class="hlt">air</span> from contamination by outgassing of <span class="hlt">sampling</span> and control devices. The <span class="hlt">sampling</span> is performed during the descent of the system. Vertical profiles of mixing ratios of CF2Cl2, CFCl3 and CH4 are given. Mixing ratios of CF2Cl2 and CFCl3 in the stratosphere do not show the discernible effect of the increase of those in the ground level background, and decrease with altitude. Decreasing rate of CFCl3 is larger than that of CF2Cl2. CH4 mixing ratio, on the other hand, shows diffusive equilibrium, as the photodissociation cross section of CH4 is small and concentrations of OH radical and 0(sup I D) are low.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4587002','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4587002"><span>Enhancing indoor <span class="hlt">air</span> quality –The <span class="hlt">air</span> filter advantage</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Vijayan, Vannan Kandi; Paramesh, Haralappa; Salvi, Sundeep Santosh; Dalal, Alpa Anil Kumar</p> <p>2015-01-01</p> <p><span class="hlt">Air</span> pollution has become the world's single biggest environmental health risk, linked to around 7 million deaths in 2012 according to a recent World Health Organisation (WHO) report. The new data further <span class="hlt">reveals</span> a stronger link between, indoor and outdoor <span class="hlt">air</span> pollution exposure and cardiovascular diseases, such as strokes and ischemic heart disease, as well as between <span class="hlt">air</span> pollution and cancer. The role of <span class="hlt">air</span> pollution in the development of respiratory diseases, including acute respiratory infections and chronic obstructive pulmonary diseases, is well known. While both indoor and outdoor pollution affect health, recent statistics on the impact of household indoor pollutants (HAP) is alarming. The WHO factsheet on HAP and health states that 3.8 million premature deaths annually - including stroke, ischemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer are attributed to exposure to household <span class="hlt">air</span> pollution. Use of <span class="hlt">air</span> cleaners and filters are one of the suggested strategies to improve indoor <span class="hlt">air</span> quality. This review discusses the impact of <span class="hlt">air</span> pollutants with special focus on indoor <span class="hlt">air</span> pollutants and the benefits of <span class="hlt">air</span> filters in improving indoor <span class="hlt">air</span> quality. PMID:26628762</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/875096','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/875096"><span>Alpha-environmental continuous <span class="hlt">air</span> monitor inlet</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Rodgers, John C.</p> <p>2003-01-01</p> <p>A wind deceleration and protective shroud that provides representative <span class="hlt">samples</span> of ambient aerosols to an environmental continuous <span class="hlt">air</span> monitor (ECAM) has a cylindrical enclosure mounted to an input on the continuous <span class="hlt">air</span> monitor, the cylindrical enclosure having shrouded nozzles located radially about its periphery. Ambient <span class="hlt">air</span> flows, often along with rainwater flows into the nozzles in a <span class="hlt">sampling</span> flow generated by a pump in the continuous <span class="hlt">air</span> monitor. The <span class="hlt">sampling</span> flow of <span class="hlt">air</span> creates a cyclonic flow in the enclosure that flows up through the cylindrical enclosure until the flow of <span class="hlt">air</span> reaches the top of the cylindrical enclosure and then is directed downward to the continuous <span class="hlt">air</span> monitor. A sloped platform located inside the cylindrical enclosure supports the nozzles and causes any moisture entering through the nozzle to drain out through the nozzles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1915331S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1915331S"><span>Quantifying India's HFC emissions from whole-<span class="hlt">air</span> <span class="hlt">samples</span> collected on the UK-India Monsoon campaign</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Say, Daniel; Ganesan, Anita; O'Doherty, Simon; Bauguitte, Stephane; Rigby, Matt; Lunt, Mark</p> <p>2017-04-01</p> <p>With a population exceeding 1 billion and a rapidly expanding economy, greenhouse gas (GHG) emissions from India are of global significance. As of 2010, India's anthropogenic GHG emissions accounted for 5.6% of the global total, with this share predicted to grow significantly in the coming decades. We focus here on hydrofluorocarbons (HFCs), a diverse range of potent GHGs, whose role as replacements for ozone-depleting CFCs and HCFCs in <span class="hlt">air</span>-conditioning and refrigeration applications (among others) has led to rapid atmospheric accumulation. Recent efforts to reduce their consumption (and subsequent emission) culminated in an amendment to the Montreal Protocol; member states are now required to phase-down their use of HFCs, with the first cuts planned for 2019. Despite the potential climate implications, atmospheric measurements of HFCs in India, required for quantifying their emissions using top-down inverse methods, have not previously existed. Here we present the first Indian hydrofluorocarbon (HFC) observations, obtained during two months of low altitude (<2000 m) flights. Of the 176 whole <span class="hlt">air</span> <span class="hlt">samples</span> collected on board the UK's NERC-FAAM (Facility for Airborne Atmospheric Measurements) research aircraft, the majority were obtained above the Indo-Gangetic Plains of Northern India, where population density is greatest. Using a small subset of <span class="hlt">samples</span> filled above the Arabian Sea, we derive compound specific baselines, to which the remaining <span class="hlt">samples</span> are compared. Significant mole fraction enhancements are observed for all major HFCs, indicating the presence of regional emissions sources. Little enhancement is observed in the concentration of various HFC predecessors, including CFCs, suggesting India's success in phasing out the majority of ozone depleting substances. Using these atmospheric observations and the NAME (Numerical Atmospheric dispersion Modelling Environment) atmospheric transport model, we present the first regional HFC flux estimates for India.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/19795','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/19795"><span>The Chace <span class="hlt">air</span> indicator.</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>1981-01-01</p> <p>The study reported here has <span class="hlt">revealed</span> very poor agreement between <span class="hlt">air</span> contents determined by the Chace <span class="hlt">air</span> indicator (CAI) and those by the pressure method. In tests of highway concretes the pressure method gave values typically 30% higher than antici...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3764502','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3764502"><span>Simulating and explaining passive <span class="hlt">air</span> <span class="hlt">sampling</span> rates for semi-volatile compounds on polyurethane foam passive samplers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Petrich, Nicholas T.; Spak, Scott N.; Carmichael, Gregory R.; Hu, Dingfei; Martinez, Andres; Hornbuckle, Keri C.</p> <p>2013-01-01</p> <p>Passive <span class="hlt">air</span> samplers (PAS) including polyurethane foam (PUF) are widely deployed as an inexpensive and practical way to <span class="hlt">sample</span> semi-volatile pollutants. However, concentration estimates from PAS rely on constant empirical mass transfer rates, which add unquantified uncertainties to concentrations. Here we present a method for modeling hourly <span class="hlt">sampling</span> rates for semi-volatile compounds from hourly meteorology using first-principle chemistry, physics, and fluid dynamics, calibrated from depuration experiments. This approach quantifies and explains observed effects of meteorology on variability in compound-specific <span class="hlt">sampling</span> rates and analyte concentrations; simulates nonlinear PUF uptake; and recovers synthetic hourly concentrations at a reference temperature. <span class="hlt">Sampling</span> rates are evaluated for polychlorinated biphenyl congeners at a network of Harner model samplers in Chicago, Illinois during 2008, finding simulated average <span class="hlt">sampling</span> rates within analytical uncertainty of those determined from loss of depuration compounds, and confirming quasi-linear uptake. Results indicate hourly, daily and interannual variability in <span class="hlt">sampling</span> rates, sensitivity to temporal resolution in meteorology, and predictable volatility-based relationships between congeners. We quantify importance of each simulated process to <span class="hlt">sampling</span> rates and mass transfer and assess uncertainty contributed by advection, molecular diffusion, volatilization, and flow regime within the PAS, finding PAS chamber temperature contributes the greatest variability to total process uncertainty (7.3%). PMID:23837599</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=23040&Lab=NERL&keyword=descriptive+AND+survey+AND+design&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=23040&Lab=NERL&keyword=descriptive+AND+survey+AND+design&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR COLLECTION OF PERSONAL <span class="hlt">AIR</span> <span class="hlt">SAMPLES</span> FOR ANALYSIS OF PESTICIDES OR METALS (UA-F-14.0)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The purpose of this SOP is to describe the procedure for <span class="hlt">sampling</span> personal <span class="hlt">air</span> for metals and pesticides during a predetermined time period. The SOP includes the set up of the samplers for collection of either a metals <span class="hlt">sample</span> or a pesticides <span class="hlt">sample</span>, the calibration and initial c...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26810048','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26810048"><span>Storage of cell <span class="hlt">samples</span> for ToF-SIMS experiments-How to maintain <span class="hlt">sample</span> integrity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schaepe, Kaija; Kokesch-Himmelreich, Julia; Rohnke, Marcus; Wagner, Alena-Svenja; Schaaf, Thimo; Henss, Anja; Wenisch, Sabine; Janek, Jürgen</p> <p>2016-06-25</p> <p>In order to obtain comparable and reproducible results from time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis of biological cells, the influence of <span class="hlt">sample</span> preparation and storage has to be carefully considered. It has been previously shown that the impact of the chosen preparation routine is crucial. In continuation of this work, the impact of storage needs to be addressed, as besides the fact that degradation will unavoidably take place, the effects of different storage procedures in combination with specific <span class="hlt">sample</span> preparations remain largely unknown. Therefore, this work examines different wet (buffer, water, and alcohol) and dry (<span class="hlt">air</span>-dried, freeze-dried, and critical-point-dried) storage procedures on human mesenchymal stem cell cultures. All cell <span class="hlt">samples</span> were analyzed by ToF-SIMS immediately after preparation and after a storage period of 4 weeks. The obtained spectra were compared by principal component analysis with lipid- and amino acid-related signals known from the literature. In all dry storage procedures, notable degradation effects were observed, especially for lipid-, but also for amino acid-signal intensities. This leads to the conclusion that dried <span class="hlt">samples</span> are to some extent easier to handle, yet the procedure is not the optimal storage solution. Degradation proceeds faster, which is possibly caused by oxidation reactions and cleaving enzymes that might still be active. Just as well, wet stored <span class="hlt">samples</span> in alcohol struggle with decreased signal intensities from lipids and amino acids after storage. Compared to that, the wet stored <span class="hlt">samples</span> in a buffered or pure aqueous environment <span class="hlt">revealed</span> no degradation effects after 4 weeks. However, this storage bears a higher risk of fungi/bacterial contamination, as sterile conditions are typically not maintained. Thus, regular solution change is recommended for optimized storage conditions. Not directly exposing the <span class="hlt">samples</span> to <span class="hlt">air</span>, wet storage seems to minimize oxidation effects, and hence</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5849141','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5849141"><span>Storage of cell <span class="hlt">samples</span> for ToF-SIMS experiments—How to maintain <span class="hlt">sample</span> integrity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Schaepe, Kaija; Kokesch-Himmelreich, Julia; Rohnke, Marcus; Wagner, Alena-Svenja; Schaaf, Thimo; Henss, Anja; Wenisch, Sabine; Janek, Jürgen</p> <p>2016-01-01</p> <p>In order to obtain comparable and reproducible results from time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis of biological cells, the influence of <span class="hlt">sample</span> preparation and storage has to be carefully considered. It has been previously shown that the impact of the chosen preparation routine is crucial. In continuation of this work, the impact of storage needs to be addressed, as besides the fact that degradation will unavoidably take place, the effects of different storage procedures in combination with specific <span class="hlt">sample</span> preparations remain largely unknown. Therefore, this work examines different wet (buffer, water, and alcohol) and dry (<span class="hlt">air</span>-dried, freeze-dried, and critical-point-dried) storage procedures on human mesenchymal stem cell cultures. All cell <span class="hlt">samples</span> were analyzed by ToF-SIMS immediately after preparation and after a storage period of 4 weeks. The obtained spectra were compared by principal component analysis with lipid- and amino acid-related signals known from the literature. In all dry storage procedures, notable degradation effects were observed, especially for lipid-, but also for amino acid-signal intensities. This leads to the conclusion that dried <span class="hlt">samples</span> are to some extent easier to handle, yet the procedure is not the optimal storage solution. Degradation proceeds faster, which is possibly caused by oxidation reactions and cleaving enzymes that might still be active. Just as well, wet stored <span class="hlt">samples</span> in alcohol struggle with decreased signal intensities from lipids and amino acids after storage. Compared to that, the wet stored <span class="hlt">samples</span> in a buffered or pure aqueous environment <span class="hlt">revealed</span> no degradation effects after 4 weeks. However, this storage bears a higher risk of fungi/bacterial contamination, as sterile conditions are typically not maintained. Thus, regular solution change is recommended for optimized storage conditions. Not directly exposing the <span class="hlt">samples</span> to <span class="hlt">air</span>, wet storage seems to minimize oxidation effects, and hence</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1997/0641/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1997/0641/report.pdf"><span>Results of soil, ground-water, surface-water, and streambed-sediment <span class="hlt">sampling</span> at <span class="hlt">Air</span> Force Plane 85, Columbus, Ohio, 1996</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Parnell, J.M.</p> <p>1997-01-01</p> <p>The U.S. Geological Survey (USGS), in cooperation with Aeronautical Systems Center, Environmental Management Directorate, Restoration Division, prepared the Surface- and Ground- Water Monitoring Work Plan for <span class="hlt">Air</span> Force Plant 85 (AFP 85 or Plant), Columbus, Ohio, under the <span class="hlt">Air</span> Force Installation Restoration Program to characterize any ground-water, surface-water, and soil contamination that may exist at AFP 85. The USGS began the study in November 1996. The Plant was divided into nine <span class="hlt">sampling</span> areas, which included some previously investi gated study sites. The investigation activities included the collection and presentation of data taken during drilling and water-quality <span class="hlt">sampling</span>. Data collection focused on the saturated and unsatur ated zones and surface water. Twenty-three soil borings were completed. Ten monitoring wells (six existing wells and four newly constructed monitoring wells) were selected for water-quality sam pling. Surface-water and streambed-sediment <span class="hlt">sampling</span> locations were chosen to monitor flow onto and off of the Plant. Seven sites were <span class="hlt">sampled</span> for both surface-water and streambed-sediment quality. This report presents data on the selected inorganic and organic constituents in soil, ground water, surface water, and streambed sediments at AFP 85. The methods of data collection and anal ysis also are included. Knowledge of the geologic and hydrologic setting could aid Aeronautical Systems Center, Environmental Management Directorate, Restoration Division, and its governing regulatory agencies in future remediation studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28535600','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28535600"><span>New approach to resolve the humidity problem in VOC determination in outdoor <span class="hlt">air</span> <span class="hlt">samples</span> using solid adsorbent tubes followed by TD-GC-MS.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maceira, Alba; Vallecillos, Laura; Borrull, Francesc; Marcé, Rosa Maria</p> <p>2017-12-01</p> <p>This study describes the humidity effect in the <span class="hlt">sampling</span> process by adsorbent tubes followed by thermal desorption and gas chromatography-mass spectrometry (TD-GC-MS) for the determination of volatile organic compounds (VOCs) in <span class="hlt">air</span> <span class="hlt">samples</span> and evaluates possible solutions to this problem. Two multi-sorbent bed tubes, Tenax TA/Carbograph 1TD and Carbotrap B/Carbopack X/Carboxen 569, were tested in order to evaluate their behaviour in the presence of environmental humidity. Humidity problems were demonstrated with carbon-based tubes, while Tenax-based tubes did not display any influence. Silica gel, a molecular sieve and CaCl 2 were tried out as materials for drying tube to remove <span class="hlt">air</span> humidity, placed prior to the <span class="hlt">sampling</span> tube to prevent water from entering. The pre-tubes filled with 0.5g of CaCl 2 showed the best results with respect to their blanks, the analytes recoveries and their ability to remove ambient humidity. To avoid the possible agglomeration of CaCl 2 during the <span class="hlt">sampling</span> process in high relative humidity atmospheres, 0.1g of diatomaceous earth were mixed with the desiccant agent. The applicability of the CaCl 2 pre-tube as drying agent prior to Carbotrap B/Carbopack X/Carboxen 569 tubes was tested in urban and industrial locations with <span class="hlt">samplings</span> of <span class="hlt">air</span> at high relative humidity. In addition, the results were compared with those obtained using Tenax TA/Carbograph 1TD tubes. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18792531','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18792531"><span>Silver zeolite antimicrobial activity in aluminium heating, ventilation and <span class="hlt">air</span> conditioning system ducts.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rizzetto, R; Mansi, A; Panatto, D; Rizzitelli, E; Tinteri, C; Sasso, T; Gasparini, R; Crovari, P</p> <p>2008-03-01</p> <p><span class="hlt">Air</span> pollution in confined environments is a serious health problem, in that most people spend long periods indoors (in homes, offices, classrooms etc.). Some people (children, the elderly, heart disease patients, asthmatic or allergic subjects) are at greater risk because of their conditions of frailty. The growing use of <span class="hlt">air</span>-conditioning systems in many public and private buildings aggravates this health risk, especially when these systems are not correctly installed or regularly serviced. The aim of our study was to verify the capacity of Ag+ ions to stop the growth of bacteria and moulds inside the ducts of Heating, Ventilation and <span class="hlt">Air</span> Conditioning system ducts (HVAC) systems when these ducts were lined with active Ag+ ions zeolite-coated panels. A Y-shaped HVAC model with two branches was used; one branch was made of traditional galvanized iron, as was the whole system, while the other was lined with active Ag+ zeolite-coated polyurethane panels. During the test, <span class="hlt">samples</span> of dust present inside both ducts were collected and seeded in liquid and solid media to detect bacteria and moulds. The presence of bacteria was also sought in the <span class="hlt">air</span> emerging from the outlets of both ducts. Tests made on <span class="hlt">samples</span> of particulate collected from the two different ducts <span class="hlt">revealed</span> a lower total bacterial load in the <span class="hlt">samples</span> collected from the Ag+ zeolite-coated duct than in the <span class="hlt">samples</span> from the traditional Zn galvanized duct. In addition, the values of bacterial load found in the <span class="hlt">air</span> emerging from the Ag+ ions zeolite-lined duct were 5 times lower than those found in the <span class="hlt">air</span> from the traditional galvanized iron duct. The utilization of Ag+ zeolite-coated panels in <span class="hlt">air</span>-conditioning systems could improve the quality of the emerging <span class="hlt">air</span> in comparison with traditional installations in galvanized iron. This innovation could prove particularly advantageous in the event of accidents during the installation of <span class="hlt">air</span>-conditioning systems or of contaminated aerosols coming from outside.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24970353','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24970353"><span>The role of open-<span class="hlt">air</span> inhalatoria in the <span class="hlt">air</span> quality improvement in spa towns.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Burkowska-But, Aleksandra; Kalwasińska, Agnieszka; Brzezinska, Maria Swiontek</p> <p>2014-08-01</p> <p>The present study was aimed at evaluating microbiological contamination of <span class="hlt">air</span> in Ciechocinek and Inowrocław - Polish lowland spa towns. Additionally, the impact of open-<span class="hlt">air</span> inhalatoria on the quality of <span class="hlt">air</span> was evaluated. <span class="hlt">Air</span> <span class="hlt">samples</span> were collected seasonally in the urban areas, in the recreation areas and in the vicinity of inhalatoria in both towns using impaction. The numbers of mesophilic bacteria, staphylococci, hemolytic bacteria and actinomycetes were determined on media according to the Polish Standard PN-86/Z-04111/02. The number of moulds was determined on media according to the Polish Standard PN-86/Z-04111/03. While the highest numbers of microorganisms were noted at the sites located in the urban areas, the lowest numbers were noted in the vicinity of the open-<span class="hlt">air</span> inhalatoria. In all the investigated <span class="hlt">air</span> <span class="hlt">samples</span> the values of bioaerosol concentrations were below the recommended TLVs (≤ 5000 CFU×m(-3) for both bacteria and fungi in outdoor environments). Location of the <span class="hlt">sampling</span> site was invariably a decisive factor in determining the number of microorganisms in the <span class="hlt">air</span>. The aerosol which is formed in the open-<span class="hlt">air</span> inhalatoria has a positive influence on microbiological <span class="hlt">air</span> quality. Owing to a unique microclimate and low <span class="hlt">air</span> contamination, Ciechocinek and Inowrocław comply with all necessary requirements set for health resorts specializing in treating upper respiratory tract infections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2101549','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2101549"><span>[An AIDS-related cognitive map in a <span class="hlt">sample</span> of drug abusers in Buenos <span class="hlt">Aires</span> City].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kornblit, A L; Bilyk, A</p> <p>1990-01-01</p> <p>This paper is an approach to AIDS as a topic among a drug abusers <span class="hlt">sample</span> of the city of Buenos <span class="hlt">Aires</span>. Research was carried out on the basis of a qualitative methodology. In an attempt at surveying opinions and attitudes of such a <span class="hlt">sample</span> as regards AIDS (i.e. subjects' cognitive map), 21 drug abusers from three different rehabilitation programs operating in the B.A. area were interviewed. On the basis of the research performed, the authors elaborate communication strategies among drug abusers that would be helpful for authorities engaged in AIDS prevention to adopt. To boost a strategy likely to break up the AIDS-drug association existing in the mind of many an abuser would be highly advisable so that a separation be settled between both representations, thus giving drug abusers a higher motivation for self-care practice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18528540','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18528540"><span>Chemical trends in background <span class="hlt">air</span> quality and the ionic composition of precipitation for the period 1980-2004 from <span class="hlt">samples</span> collected at Valentia Observatory, Co. Kerry, Ireland.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bashir, Wasim; McGovern, Frank; O'Brien, Phillip; Ryan, Margaret; Burke, Liam; Paull, Brett</p> <p>2008-06-01</p> <p>A major Irish study, based upon more than 8000 <span class="hlt">samples</span> collected over the measurement period of 22 years, for sulfur dioxide (SO2-S), sulfate (SO4-S) and nitrogen dioxide (NO2-N) concentrations (microg m(-3)) within <span class="hlt">air</span>, and the ionic composition of precipitation <span class="hlt">samples</span> based on sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), chloride (Cl-), sulfate (SO4-S), non-sea salt sulfate (nssSO4-S), ammonium (NH4-N), and nitrate (NO3-N) weighted mean concentrations (mg l(-1)), has been completed. For the <span class="hlt">air</span> <span class="hlt">samples</span>, the sulfur dioxide and sulfate concentrations decreased over the <span class="hlt">sampling</span> period (1980-2004) by 75% and 45%, respectively, whereas no significant trend was observed for nitrogen dioxide. The highest concentrations for sulfur dioxide, sulfate and nitrogen dioxide were associated with wind originating from the easterly and northeasterly directions i.e. those influenced by Irish and European sources. The lowest concentrations were associated with the westerly directions i.e. for <span class="hlt">air</span> masses originating in the North Atlantic region. This was further verified with the use of backward (back) trajectory analysis, which allowed tracing the movement of <span class="hlt">air</span> parcels using the European Centre for Medium range Weather Forecasting (ECMWF) ERA-40 re-analysis data. High non-sea salt sulfate levels were being associated with <span class="hlt">air</span> masses originating from Europe (easterlies) with lower levels from the Atlantic (westerlies). With the precipitation data, analysis of the non-sea salt sulfate concentrations showed a decrease by 47% since the measurements commenced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5015483','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5015483"><span>Characterization of the bacterial and fungal microbiome in indoor dust and outdoor <span class="hlt">air</span> <span class="hlt">samples</span>: a pilot study†</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hanson, Blake; Zhou, Yanjiao; Bautista, Eddy J.; Urch, Bruce; Speck, Mary; Silverman, Frances; Muilenberg, Michael; Phipatanakul, Wanda; Weinstock, George; Sodergren, Erica; Gold, Diane R.; Sordillo, Joanne E.</p> <p>2016-01-01</p> <p>Environmental microbes have been associated with both protective and adverse health effects in children and adults. Epidemiological studies often rely on broad biomarkers of microbial exposure (i.e. endotoxin, 1→3, Beta-D glucan), but fail to identify the taxonomic composition of the microbial community. Our aim was to characterize the bacterial and fungal microbiome in different types of environmental <span class="hlt">samples</span> collected in studies of human health effects. We determined the composition of microbial communities present in home, school and outdoor <span class="hlt">air</span> <span class="hlt">samples</span> by amplifying and sequencing regions of rRNA genes from bacteria (16S) and fungi (18S and ITS). <span class="hlt">Samples</span> for this pilot study included indoor settled dust (from both a Boston area birth cohort study on Home Allergens and Asthma (HAA)(n=12) and a study of school exposures and asthma symptoms (SICAS) (n=1)), as well as fine and coarse concentrated outdoor ambient particulate (CAP) <span class="hlt">samples</span> (n=9). Sequencing of amplified 16S, 18S, and ITS regions was performed on the Roche-454 Life Sciences Titanium pyrosequencing platform. Indoor dust <span class="hlt">samples</span> were dominated by gram-positive bacteria (Firmicutes and Actinobacteria); the most abundant bacterial genera were those related to human flora (Streptococcus, Staphylococcus, Corynebacterium and Lactobacillus). Outdoor CAPs were dominated by gram-negative Proteobacteria from water and soil sources, in particular the genera Acidovorax, and Brevundimonas (which were present at very low levels or entirely absent in indoor dust). Phylum-level fungal distributions identified by 18S or ITS regions showed very similar findings: a predominance of Ascomycota in indoor dust and Basidiomycota in outdoor CAPs. ITS sequencing of fungal genera in indoor dust showed significant proportions of Aureobasidium and Leptosphaerulina along with some contribution from Cryptococcus, Epicoccum, Aspergillus and the human commensal Malassezia. ITS sequencing detected an additional 70 fungal genera in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=biofilm&id=EJ789672','ERIC'); return false;" href="https://eric.ed.gov/?q=biofilm&id=EJ789672"><span>It's Alive!: Students Observe <span class="hlt">Air</span>-Water Interface <span class="hlt">Samples</span> Rich with Organisms</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Avant, Thomas</p> <p>2002-01-01</p> <p>This article describes an experiment, designed by Cindy Henk, manager of the Socolofsky Microscopy Center at Louisiana State University (LSU), that involved collecting and viewing microorganisms in the <span class="hlt">air</span>-water interface. The experiment was participated by Leesville High School microbiology students. The students found that the <span class="hlt">air</span>-water…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20134147','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20134147"><span>Comparison of arterial and venous blood gases and the effects of analysis delay and <span class="hlt">air</span> contamination on arterial <span class="hlt">samples</span> in patients with chronic obstructive pulmonary disease and healthy controls.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>O'Connor, T M; Barry, P J; Jahangir, A; Finn, C; Buckley, B M; El-Gammal, A</p> <p>2011-01-01</p> <p>Arterial blood gases (ABGs) are often <span class="hlt">sampled</span> incorrectly, leading to a 'mixed' or venous <span class="hlt">sample</span>. Delays in analysis and <span class="hlt">air</span> contamination are common. We measured the effects of these errors in patients with chronic obstructive pulmonary disease (COPD) exacerbations and controls. Arterial and venous <span class="hlt">samples</span> were analyzed from 30 patients with COPD exacerbation and 30 controls. Venous <span class="hlt">samples</span> were analysed immediately and arterial <span class="hlt">samples</span> separated into non-<span class="hlt">air</span>-contaminated and <span class="hlt">air</span>-contaminated specimens and analysed at 0, 30, 60, 90 and 180 min. Mean venous pH was 7.371 and arterial pH was 7.407 (p < 0.0001). There was a correlation between venous and arterial pH (r = 0.5347, p < 0.0001). The regression equation to predict arterial pH was: arterial pH = 4.2289 + 0.43113 · venous pH. There were no clinically significant differences in arterial PO₂ associated with analysis delay. A statistically significant decline in pH was detected at 30 min in patients with COPD exacerbation (p = 0.0042) and 90 min in controls (p < 0.0001). A clinically significant decline in pH emerged at 73 min in patients with COPD exacerbation and 87 min in controls. <span class="hlt">Air</span> contamination was associated with a clinically significant increase in PO₂ in all <span class="hlt">samples</span>, including those that were immediately analyzed. Arterial and venous pH differ significantly. Venous pH cannot accurately replace arterial pH. Temporal delays in ABG analysis result in a significant decline in measured pH. ABGs should be analysed within 30 min. <span class="hlt">Air</span> contamination leads to an immediate increase in measured PO₂, indicating that <span class="hlt">air</span>-contaminated ABGs should be discarded. Copyright © 2010 S. Karger AG, Basel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29331671','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29331671"><span>The molecular characteristics of avian influenza viruses (H9N2) derived from <span class="hlt">air</span> <span class="hlt">samples</span> in live poultry markets.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Yanheng; Lin, Jinsi; Yang, Shuhuan; Xie, Ying; Wang, Man; Chen, Xueqin; Zhu, Yayang; Luo, Le; Shi, Wuyang</p> <p>2018-06-01</p> <p>To study the molecular characteristics of H9N2-subtype avian influenza viruses (AIVs) isolated from <span class="hlt">air</span> <span class="hlt">samples</span> collected in live poultry markets (LPMs) and explore their sequence identities with AIVs that caused human infection. Weekly surveillance of H9N2-subtype AIVs in the <span class="hlt">air</span> of LPMs was conducted from 2015 to 2016. H9-positive <span class="hlt">samples</span> were isolated from chicken embryos. Whole genome sequences of the isolated AIVs were obtained through high-throughput sequencing. Phylogenetic analysis and key loci variations of the sequences were further analyzed. A total of 327 aerosol <span class="hlt">samples</span> were collected from LPMs. Nine <span class="hlt">samples</span> were positive for H9-subtype AIVs based on quantitative real-time reverse transcription polymerase chain reaction (qRRT-PCR). According to the whole genome sequence analysis and phylogenetic analysis, except for the A/Environment/Zhongshan/ZS201505/2015 (ZS201505) strain, 8 gene segments of 8 aerosol H9N2 isolates and 2 H9N2 human isolates in 2015 were located in the same clade. Among key loci variations, except for the ZS201505 strain, H9N2-subtype AIVs had no mutations in eight receptor binding sites of hemagglutinin (HA), and stalks of neuraminidase (NA) proteins exhibited a deletion site of three bases. The PA gene of ZS201503 and ZS201602 exhibited an L336M mutation. The N30D and T215A mutations in the M1 gene and amino acid residues L89V in PB2, P42S in NS1 and S31N in M2 were retained in these 9 strains of H9N2 isolates, which could enhance the virus's virulence. Live H9N2 AIVs survived in the aerosol of LPMs in Zhongshan City. The aerosol viruses had a close evolutionary relationship with human epidemic strains, indicating that there might be a risk of AIV transmission from polluted aerosols in LPMs to humans. Mutations in H9N2-subtype AIVs isolated from <span class="hlt">air</span> <span class="hlt">samples</span> collected from LPMs suggested their pathogenicity was enhanced to infect humans. Copyright © 2018. Published by Elsevier B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992AtmEn..26..819D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992AtmEn..26..819D"><span>Determination of formaldehyde by HPLC as the DNPH derivative following high-volume <span class="hlt">air</span> <span class="hlt">sampling</span> onto bisulfite-coated cellulose filters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Andrade, Jailson B.; Tanner, Roger L.</p> <p></p> <p>A method is described for the specific collection of formaldehyde as hydroxymethanesulfonate on bisulfate-coated cellulose filters. Following extraction in aqueous acid and removal on unreacted bisulfite, the hydroxymethanesulfonate is decomposed by base, and HCHO is determined by DNPH (2,4-dinitrophenylhydrazine) derivatization and HPLC. Since the collection efficiency for formaldehyde is moderately high even when <span class="hlt">sampling</span> ambient <span class="hlt">air</span> at high-volume flow rates, a limit of detection of 0.2 ppbv is achieved with 30 min <span class="hlt">sampling</span> times. Interference from acetaldehyde co-collected as 1-hydroxyethanesulfonate is <5% using this procedure. The technique shows promise for both short-term airborne <span class="hlt">sampling</span>, and as a means of collecting mg-sized <span class="hlt">samples</span> of HCHO on an inorganic matrix for carbon isotopic analyses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.A53D0282S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.A53D0282S"><span>Using GMD Data, <span class="hlt">AIRS</span> Measurements, and the NASA Chemistry-Climate Model to <span class="hlt">Reveal</span> Regional and Seasonal Variation of Methane</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steele, K. J.; Duncan, B. N.; Warner, J. X.; Nielsen, J. E.</p> <p>2010-12-01</p> <p> model <span class="hlt">revealed</span> that variation in source strength is dependent on the site location in relation to the source strength. Assessing CH4 source contributions to the UT <span class="hlt">revealed</span> that variability is affected by seasonal variation in the sources convolved with seasonal variation in deep convection. More work is needed in order to constrain sources of atmospheric CH4. However, surface and tropospheric in situ data can be used to validate <span class="hlt">AIRS</span> observations so that CH4 can be monitored at a global scale, and CCM output can aid in determining which sources have the largest contribution to atmospheric CH4.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcSpe.123..157A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcSpe.123..157A"><span>Quantification of fluorine traces in solid <span class="hlt">samples</span> using CaF molecular emission bands in atmospheric <span class="hlt">air</span> Laser-Induced Breakdown Spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alvarez-Llamas, C.; Pisonero, J.; Bordel, N.</p> <p>2016-09-01</p> <p>Direct solid determination of trace amounts of fluorine using Laser-Induced Breakdown Spectroscopy (LIBS) is a challenging task due to the low excitation efficiency of this element. Several strategies have been developed to improve the detection capabilities, including the use of LIBS in a He atmosphere to enhance the signal to background ratios of F atomic emission lines. An alternative method is based on the detection of the molecular compounds that are formed with fluorine in the LIBS plasma. In this work, the detection of CaF molecular emission bands is investigated to improve the analytical capabilities of atmospheric <span class="hlt">air</span> LIBS for the determination of fluorine traces in solid <span class="hlt">samples</span>. In particular, Cu matrix <span class="hlt">samples</span> containing different fluorine concentration (between 50 and 600 μg/g), and variable amounts of Ca, are used to demonstrate the linear relationships between CaF emission signal and F concentration. Limits of detection for fluorine are improved by more than 1 order of magnitude using CaF emission bands versus F atomic lines, in atmospheric-<span class="hlt">air</span> LIBS. Furthermore, a toothpaste powder <span class="hlt">sample</span> is used to validate this analytical method. Good agreement is observed between the nominal and the predicted fluorine mass-content.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title30-vol1/pdf/CFR-2010-title30-vol1-sec71-701.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title30-vol1/pdf/CFR-2010-title30-vol1-sec71-701.pdf"><span>30 CFR 71.701 - <span class="hlt">Sampling</span>; general requirements.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 30 Mineral Resources 1 2010-07-01 2010-07-01 false <span class="hlt">Sampling</span>; general requirements. 71.701 Section... MINES Airborne Contaminants § 71.701 <span class="hlt">Sampling</span>; general requirements. (a) <span class="hlt">Air</span> <span class="hlt">samples</span> will be taken by... operator shall conduct any additional <span class="hlt">air</span> <span class="hlt">sampling</span> tests and analyses as the Secretary may from time to...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec71-701.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title30-vol1/pdf/CFR-2011-title30-vol1-sec71-701.pdf"><span>30 CFR 71.701 - <span class="hlt">Sampling</span>; general requirements.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 30 Mineral Resources 1 2011-07-01 2011-07-01 false <span class="hlt">Sampling</span>; general requirements. 71.701 Section... MINES Airborne Contaminants § 71.701 <span class="hlt">Sampling</span>; general requirements. (a) <span class="hlt">Air</span> <span class="hlt">samples</span> will be taken by... operator shall conduct any additional <span class="hlt">air</span> <span class="hlt">sampling</span> tests and analyses as the Secretary may from time to...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27461238','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27461238"><span>Study of the ambient <span class="hlt">air</span> metallic elements Cr, Cu, Zn, Cd and Pb at HAF <span class="hlt">sampling</span> sites.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fang, Guor-Cheng; Kuo, Yu-Chen; Zhuang, Yuan-Jie; Tsai, Kai-Hsiang; Huang, Wen-Chuan</p> <p>2017-08-01</p> <p>This study characterized diurnal variations in the compositions of total suspended particulates (TSP) and dry deposits of particulates from ambient <span class="hlt">air</span>, and the metallic elements that are contained in them at harbor, airport and farmland (HAF) <span class="hlt">sampling</span> sites from August, 2013 to July, 2014. Two-way ANOVA of the amounts of metallic elements in the TSP and dry deposits was carried out in all four seasons at the HAF <span class="hlt">sampling</span> sites. The metallic elements Cr and Cu originated in local emission sources at the airport. Metallic elements Zn and Pb originated in local emission sources at the harbor. Finally, metallic element Cd originated in local emissions form farmland. The following results were also obtained. (1) The metallic composition of the TSP differed significantly from that of the dry deposits in all four seasons at the harbor and farmland <span class="hlt">sampling</span> sites, but not at the airport <span class="hlt">sampling</span> site. (2) High correlations coefficients were found between the amounts of metallic elements Cr and Cu in the TSP and those in the dry deposits at the airport <span class="hlt">sampling</span> site. (3) Pb was present in the TSP and the dry deposits at the harbor <span class="hlt">sampling</span> site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11936027','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11936027"><span>Microbiological contamination of compressed <span class="hlt">air</span> used in dentistry: an investigation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Conte, M; Lynch, R M; Robson, M G</p> <p>2001-11-01</p> <p>The purpose of this preliminary investigation was twofold: 1) to examine the possibility of cross-contamination between a dental-evacuation system and the compressed <span class="hlt">air</span> used in dental operatories and 2) to capture and identify the most common microflora in the compressed-<span class="hlt">air</span> supply. The investigation used swab, water, and <span class="hlt">air</span> <span class="hlt">sampling</span> that was designed to track microorganisms from the evacuation system, through the <span class="hlt">air</span> of the mechanical room, into the compressed-<span class="hlt">air</span> system, and back to the patient. <span class="hlt">Samples</span> taken in the vacuum system, the <span class="hlt">air</span> space in the mechanical room, and the compressed-<span class="hlt">air</span> storage tank had significantly higher total concentrations of bacteria than the outside <span class="hlt">air</span> <span class="hlt">sampled</span>. <span class="hlt">Samples</span> of the compressed <span class="hlt">air</span> returning to the operatory were found to match the outside <span class="hlt">air</span> <span class="hlt">sample</span> in total bacteria. It was concluded that the <span class="hlt">air</span> dryer may have played a significant role in the elimination of microorganisms from the dental compressed-<span class="hlt">air</span> supply.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Trichloroethylene&id=ED084105','ERIC'); return false;" href="https://eric.ed.gov/?q=Trichloroethylene&id=ED084105"><span>Review of Various <span class="hlt">Air</span> <span class="hlt">Sampling</span> Methods for Solvent Vapors.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Maykoski, R. T.</p> <p></p> <p>Vapors of trichloroethylene, toluene, methyl ethyl ketone, and butyl cellosolve in <span class="hlt">air</span> were collected using Scotchpac and Tedlar bags, glass prescription bottles, and charcoal adsorption tubes. Efficiencies of collection are reported. (Author/RH)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24091122','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24091122"><span>α-Pinene, 3-carene and d-limonene in indoor <span class="hlt">air</span> of Polish apartments: the impact on <span class="hlt">air</span> quality and human exposure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Król, Sylwia; Namieśnik, Jacek; Zabiegała, Bożena</p> <p>2014-01-15</p> <p>Monoterpenes are among most ubiquitous volatile organic compounds (VOCs) to be detected in indoor <span class="hlt">air</span>. Since the quality of indoor <span class="hlt">air</span> is considered important for inhabitants' well-being, the present study aimed at investigating impact of human activity on levels of selected monoterpenes applying passive <span class="hlt">sampling</span> technique followed by thermal desorption and gas chromatography coupled mass spectrometry. One of the objectives of the present work was to identify and characterize main emission sources as well as to investigate relationship between selected monoterpenes in indoor <span class="hlt">air</span>. Concentration levels obtained for studied monoterpenes varied from 3 μg m(-3) for 3-carene to 1261 μg m(-3) for d-limonene. D-limonene was reported the most abundant of studied monoterpenes in indoor <span class="hlt">air</span>. The strong correlation observed between monoterpenes suggests that studied compounds originate from same emission sources, while the I/O >1 proves the strong contribution of endogenous emission sources. The in-depth study of day-night fluctuations in concentrations of monoterpenes lead to the conclusion that human presence and specific pattern of behavior strongly influences presence and concentrations of VOCs in indoor environment. The evaluation of human exposure to selected monoterpenes via inhalation of <span class="hlt">air</span> <span class="hlt">revealed</span> that infants, toddlers and young children were the highly exposed individuals. © 2013.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/871996','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/871996"><span>Remote possibly hazardous content container <span class="hlt">sampling</span> device</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Volz, David L.</p> <p>1998-01-01</p> <p>The present invention relates to an apparatus capable of <span class="hlt">sampling</span> enclosed containers, where the contents of the container is unknown. The invention includes a compressed <span class="hlt">air</span> device capable of supplying <span class="hlt">air</span> pressure, device for controlling the amount of <span class="hlt">air</span> pressure applied, a pneumatic valve, a <span class="hlt">sampling</span> device having a hollow, <span class="hlt">sampling</span> insertion needle suspended therein and device to communicate fluid flow between the container and a containment vessel, pump or direct reading instrument.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA221074','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA221074"><span>Field Evaluation of a Passive <span class="hlt">Sampling</span> Device for Hydrazines in Ambient <span class="hlt">Air</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1990-04-06</p> <p>MANIDIFUIOFOBELFO Figure 2. Test gas generator schematic. Conditioned house- compressed <span class="hlt">air</span> is used as the diluent. The conditioning procedure consists...of passing the house <span class="hlt">air</span> through a series of demisters, a hot Hopcalite catalyst bed, a reciprocating dual-tower molecular sieve scrubber, and finally... <span class="hlt">Air</span> P. A. TAFFE,* S. W. BROWN,** A. R. THUROW,*** J. C. TRAvIs**** *GEO-Centers Inc., **EG&G, BOC-022, KSC, FL . . F. ***Wiltech Corp., KSC, FL MAY 0</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22284870','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22284870"><span>Simultaneous <span class="hlt">sampling</span> and analysis of indoor <span class="hlt">air</span> infested with Cimex lectularius L. (Hemiptera: Cimicidae) by solid phase microextraction, thin film microextraction and needle trap device.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Eom, In-Yong; Risticevic, Sanja; Pawliszyn, Janusz</p> <p>2012-02-24</p> <p><span class="hlt">Air</span> in a room infested by Cimex lectularius L. (Hemiptera: Cimicidae) was <span class="hlt">sampled</span> simultaneously by three different <span class="hlt">sampling</span> devices including solid phase microextraction (SPME) fiber coatings, thin film microextraction (TFME) devices, and needle trap devices (NTDs) and then analyzed by gas chromatography-mass spectrometry (GC-MS). The main focus of this study was to fully characterize indoor <span class="hlt">air</span> by identifying compounds extracted by three different microextraction formats and, therefore, perform both the device comparison and more complete characterization of C. lectularius pheromone. The NTD technique was capable of extracting both (E)-2-hexenal and (E)-2-octenal, which were previously identified as alarm pheromones of bedbugs, and superior NTD recoveries for these two components allowed reliable identification based on mass spectral library searching and linear temperature programmed retention index (LTPRI) technique. While the use of DVB/CAR/PDMS SPME fiber coatings provided complementary <span class="hlt">sample</span> fingerprinting and profiling results, TFME <span class="hlt">sampling</span> devices provided discriminative extraction coverage toward highly volatile analytes. In addition to two alarm pheromones, relative abundances of all other analytes were recorded for all three devices and aligned across all examined <span class="hlt">samples</span>, namely, highly infested area, less infested area, and control <span class="hlt">samples</span> which were characterized by different bedbug populations. The results presented in the current study illustrate comprehensive characterization of infested indoor <span class="hlt">air</span> <span class="hlt">samples</span> through the use of three different non-invasive SPME formats and identification of novel components comprising C. lectularius pheromone, therefore, promising future alternatives for use of potential synthetic pheromones for detection of infestations. Copyright © 2011 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=147763&keyword=process+AND+improvement&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=147763&keyword=process+AND+improvement&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>COMPARISON OF 24H AVERAGE VOC MONITORING RESULTS FOR RESIDENTIAL INDOOR AND OUTDOOR <span class="hlt">AIR</span> USING CARBOPACK X-FILLED DIFFUSIVE SAMPLERS AND ACTIVE <span class="hlt">SAMPLING</span> - A PILOT STUDY</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Analytical results obtained by thermal desorption GC/MS for 24h diffusive <span class="hlt">sampling</span> of 11 volatile organic compounds (VOCs) are compared with results of time-averaged active <span class="hlt">sampling</span> at a known constant flow rate. <span class="hlt">Air</span> <span class="hlt">samples</span> were collected with co-located duplicate diffusive samp...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA538029','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA538029"><span>Demonstration/Validation of the Snap Sampler Passive Groundwater <span class="hlt">Sampling</span> Device at the Former McClellan <span class="hlt">Air</span> Force Base</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2011-02-01</p> <p>and Development Center Fe Iron gpd Gallons per Day HDPE High Density Polyethylene Hg Mercury ICP Inductively Coupled Plasma ICP/MS...Inductively Coupled Plasma Mass Spectrometry IROD Interim Record of Decision ITRC Interstate Technology and Regulatory Council K Potassium Kow...alkaline earth metals, alkali metals, and a metalloid, were <span class="hlt">sampled</span>. This particular demonstration took place at the McClellan <span class="hlt">Air</span> Force Base (AFB) in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28633115','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28633115"><span>Occurrence of commonly used pesticides in personal <span class="hlt">air</span> <span class="hlt">samples</span> and their associated health risk among paddy farmers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hamsan, Hazwanee; Ho, Yu Bin; Zaidon, Siti Zulfa; Hashim, Zailina; Saari, Nazamid; Karami, Ali</p> <p>2017-12-15</p> <p>Tanjung Karang, Selangor, is widely known for its paddy cultivation activity and hosts the third largest paddy field in Malaysia. Pesticides contamination in agriculture fields has become an unavoidable problem, as pesticides are used to increase paddy productivity and reduce plant disease. Human exposure to agrichemicals is common and could results in both acute and chronic health effects, such as acute and chronic neurotoxicity. This study aims to determine the concentrations of commonly used pesticides (azoxystrobin, buprofezin, chlorantraniliprole, difenoconazole, fipronil, imidacloprid, isoprothiolane, pretilachlor, propiconazole, pymetrozine, tebuconazole, tricyclazole, and trifloxystrobin) in personal <span class="hlt">air</span> <span class="hlt">samples</span> and their associated health risks among paddy farmers. Eighty-three farmers from Tangjung Karang, Selangor were involved in this study. A solid sorbent tube was attached to the farmer's breathing zone with a clip, and an <span class="hlt">air</span> pump was fastened to the belt to collect personal <span class="hlt">air</span> <span class="hlt">samples</span>. Pesticides collected in the XAD-2 resin were extracted with acetone, centrifuged, concentrated via nitrogen blowdown and reconstituted with 1mL of 3:1 ultrapure water/HPLC-grade methanol solution. The extract was analyzed using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The target compounds were detected with a maximum concentration reaching up to 462.5ngm -3 (fipronil). The hazard quotient (HQ) was less than 1 and the hazard index (HI) value was 3.86×10 -3 , indicating that the risk of pesticides related diseases was not significant. The lifetime cancer risk (LCR) for pymetrozine was at an acceptable level (LCR<10 -6 ) with 4.10×10 -8 . The results reported in this study can be beneficial in terms of risk management within the agricultural community. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21277649','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21277649"><span>Environmental survey to assess viral contamination of <span class="hlt">air</span> and surfaces in hospital settings.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carducci, A; Verani, M; Lombardi, R; Casini, B; Privitera, G</p> <p>2011-03-01</p> <p>The presence of pathogenic viruses in healthcare settings represents a serious risk for both staff and patients. Direct viral detection in the environment poses significant technical problems and the indirect indicators currently in use suffer from serious limitations. The aim of this study was to monitor surfaces and <span class="hlt">air</span> in hospital settings to <span class="hlt">reveal</span> the presence of hepatitis C virus, human adenovirus, norovirus, human rotavirus and torque teno virus by nucleic acid assays, in parallel with measurements of total bacterial count and haemoglobin presence. In total, 114 surface and 62 <span class="hlt">air</span> <span class="hlt">samples</span> were collected. Bacterial contamination was very low (<1 cfu/cm(2)) on surfaces, whereas the 'medium' detected value in <span class="hlt">air</span> was 282 cfu/m(3). Overall, 19 (16.7%) surface <span class="hlt">samples</span> tested positive for viral nucleic acids: one for norovirus, one for human adenovirus and 17 (14.9%) for torque teno virus (TTV). Only this latter virus was directly detected in 10 <span class="hlt">air</span> <span class="hlt">samples</span> (16.1%). Haemoglobin was found on two surfaces. No relationship was found between viral, biochemical or bacterial indicators. The data obtained confirm the difficulty of assessing viral contamination using bacterial indicators. The frequent detection of TTV suggests its possible use as an indicator for general viral contamination of the environment. Copyright © 2010 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol33/pdf/CFR-2014-title40-vol33-sec1065-805.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol33/pdf/CFR-2014-title40-vol33-sec1065-805.pdf"><span>40 CFR 1065.805 - <span class="hlt">Sampling</span> system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... 40 Protection of Environment 33 2014-07-01 2014-07-01 false <span class="hlt">Sampling</span> system. 1065.805 Section 1065.805 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) <span class="hlt">AIR</span> POLLUTION CONTROLS... background <span class="hlt">samples</span> for correcting dilution <span class="hlt">air</span> for background concentrations of alcohols and carbonyls. (c...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1065-805.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1065-805.pdf"><span>40 CFR 1065.805 - <span class="hlt">Sampling</span> system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... 40 Protection of Environment 34 2012-07-01 2012-07-01 false <span class="hlt">Sampling</span> system. 1065.805 Section 1065.805 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) <span class="hlt">AIR</span> POLLUTION CONTROLS... background <span class="hlt">samples</span> for correcting dilution <span class="hlt">air</span> for background concentrations of alcohols and carbonyls. (c...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol34/pdf/CFR-2013-title40-vol34-sec1065-805.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol34/pdf/CFR-2013-title40-vol34-sec1065-805.pdf"><span>40 CFR 1065.805 - <span class="hlt">Sampling</span> system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... 40 Protection of Environment 34 2013-07-01 2013-07-01 false <span class="hlt">Sampling</span> system. 1065.805 Section 1065.805 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) <span class="hlt">AIR</span> POLLUTION CONTROLS... background <span class="hlt">samples</span> for correcting dilution <span class="hlt">air</span> for background concentrations of alcohols and carbonyls. (c...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850065472&hterms=Sound+absorption+Wall&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DSound%2Babsorption%2BWall','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850065472&hterms=Sound+absorption+Wall&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DSound%2Babsorption%2BWall"><span>Low-frequency absorption of sound in <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zuckerwar, A. J.; Meredith, R. W.</p> <p>1985-01-01</p> <p>Thirty sets of sound absorption measurements in <span class="hlt">air</span> at a pressure of 1 atmosphere are presented at temperatures from 10 C to 50 C, relative humidities from 0 to 100 percent, and frequencies from 10 to 2500 Hz. The measurements were conducted by the method of free decay in a resonant tube having a length of 18.261 m and bore diameter of 0.152 m. Background measurements in a gas consisting of 89.5 percent N2 and 10.5 percent Ar, a mixture which has the same sound velocity as <span class="hlt">air</span>, permitted the wall and structural losses of the tube to be separated from the constituent absorption, consisting of classical rotational and vibrational absorption, in the <span class="hlt">air</span> <span class="hlt">samples</span>. The data were used to evaluate the vibrational relaxation frequencies of N2 and/or O2 for each of the 30 sets of meteorological parameters. Over the full range of humidity, the measured relaxation frequencies of N2 in <span class="hlt">air</span> lie between those specified by ANSI Standard S1.26-1978 and those measured earlier in binary N2H2O mixtures. The measured relaxation frequencies could be determined only at very low values of humidity, <span class="hlt">reveal</span> a significant trend away from the ANSI standard, in agreement with a prior investigation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850003481','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850003481"><span>Low-frequency sound absorption measurements in <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zuckerwar, A. J.; Meredith, R. W.</p> <p>1984-01-01</p> <p>Thirty sets of sound absorption measurements in <span class="hlt">air</span> at a pressure of 1 atmosphere are presented at temperatures from 10 C to 50 C, relative humidities from 0 to 100 percent, and frequencies from 10 to 2500 Hz. The measurements were conducted by the method of free decay in a resonant tube having a length of 18.261 m and bore diameter of 0.152 m. Background measurements in a gas consisting of 89.5 percent N2 and 10.5 percent Ar, a mixture which has the same sound velocity as <span class="hlt">air</span>, permitted the wall and structural losses of the tube to be separated from the constituent absorption, consisting of classical rotational and vibrational absorption, in the <span class="hlt">air</span> <span class="hlt">samples</span>. The data were used to evaluate the vibrational relaxation frequencies of N2 and/or O2 for each of the 30 sets of meteorological parameters. Over the full range of humidity, the measured relaxation frequencies of N2 in <span class="hlt">air</span> lie between those specified by ANSI Standard S1.26-1978 and those measured earlier in binary N2H2O mixtures. The measured relaxation frequencies could be determined only at very low values of humidity, <span class="hlt">reveal</span> a significant trend away from the ANSI standard, in agreement with a prior investigation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26064381','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26064381"><span><span class="hlt">Air</span>-conditioner filters enriching dust mites allergen.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhan, Xiaodong; Li, Chaopin; Xu, Haifeng; Xu, Pengfei; Zhu, Haibin; Diao, Jidong; Li, Na; Zhao, Beibei</p> <p>2015-01-01</p> <p>We detected the concentration of dust mites allergen (Der f1 & Der p1) in the <span class="hlt">air</span> of different places before and after the starting of <span class="hlt">air</span>-conditioners in Wuhu City, Anhui, China, and to discuss the relation between the dust mites allergen in <span class="hlt">air</span>-conditioner filters and the asthma attack. The dust <span class="hlt">samples</span> were collected from the <span class="hlt">air</span>-conditioner filters in dining rooms, shopping malls, hotels and households respectively. Concentrations of dust mites major group allergen 1 (Der f 1, Der p1) were detected with enzyme linked immunosorbent assay (ELISA), and the dust mite immune activities were determined by dot-ELISA. The concentration of Der f1 in dining rooms, shopping malls, hotels and households was 1.52 μg/g, 1.24 μg/g, 1.31 μg/g and 1.46 μg/g respectively, and the concentration of Der p1 in above-mentioned places was 1.23 μg/g, 1.12 μg/g, 1.16 μg/g and 1.18 μg/g respectively. The concentration of Der f1 & Der p1 in <span class="hlt">air</span> was higher after the <span class="hlt">air</span>-conditioners starting one hours later, and the difference was significant (P<0.05, respectively). Additionally, dot-ELISA findings <span class="hlt">revealed</span> that the allergen extracted from the dust was capable of reacting with IgE from the sera of asthma mice allergic to dust mites. The study concludes that <span class="hlt">air</span>-conditioner filters can enrich dust mites major group allergen, and the allergens can induce asthma. The <span class="hlt">air</span>-conditioner filters shall be cleaned or replaced regularly to prevent or reduce accumulation of the dust mites and its allergens.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4443215','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4443215"><span><span class="hlt">Air</span>-conditioner filters enriching dust mites allergen</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhan, Xiaodong; Li, Chaopin; Xu, Haifeng; Xu, Pengfei; Zhu, Haibin; Diao, Jidong; Li, Na; Zhao, Beibei</p> <p>2015-01-01</p> <p>We detected the concentration of dust mites allergen (Der f1 & Der p1) in the <span class="hlt">air</span> of different places before and after the starting of <span class="hlt">air</span>-conditioners in Wuhu City, Anhui, China, and to discuss the relation between the dust mites allergen in <span class="hlt">air</span>-conditioner filters and the asthma attack. The dust <span class="hlt">samples</span> were collected from the <span class="hlt">air</span>-conditioner filters in dining rooms, shopping malls, hotels and households respectively. Concentrations of dust mites major group allergen 1 (Der f 1, Der p1) were detected with enzyme linked immunosorbent assay (ELISA), and the dust mite immune activities were determined by dot-ELISA. The concentration of Der f1 in dining rooms, shopping malls, hotels and households was 1.52 μg/g, 1.24 μg/g, 1.31 μg/g and 1.46 μg/g respectively, and the concentration of Der p1 in above-mentioned places was 1.23 μg/g, 1.12 μg/g, 1.16 μg/g and 1.18 μg/g respectively. The concentration of Der f1 & Der p1 in <span class="hlt">air</span> was higher after the <span class="hlt">air</span>-conditioners starting one hours later, and the difference was significant (P<0.05, respectively). Additionally, dot-ELISA findings <span class="hlt">revealed</span> that the allergen extracted from the dust was capable of reacting with IgE from the sera of asthma mice allergic to dust mites. The study concludes that <span class="hlt">air</span>-conditioner filters can enrich dust mites major group allergen, and the allergens can induce asthma. The <span class="hlt">air</span>-conditioner filters shall be cleaned or replaced regularly to prevent or reduce accumulation of the dust mites and its allergens. PMID:26064381</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750023546','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750023546"><span>An automated atmospheric <span class="hlt">sampling</span> system operating on 747 airliners</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Perkins, P.; Gustafsson, U. R. C.</p> <p>1975-01-01</p> <p>An <span class="hlt">air</span> <span class="hlt">sampling</span> system that automatically measures the temporal and spatial distribution of selected particulate and gaseous constituents of the atmosphere has been installed on a number of commercial airliners and is collecting data on commercial <span class="hlt">air</span> routes covering the world. Measurements of constituents related to aircraft engine emissions and other pollutants are made in the upper troposphere and lower stratosphere (6 to 12 km) in support of the Global <span class="hlt">Air</span> <span class="hlt">Sampling</span> Program (GASP). Aircraft operated by different airlines <span class="hlt">sample</span> <span class="hlt">air</span> at latitudes from the Arctic to Australia. This system includes specialized instrumentation for measuring carbon monoxide, ozone, water vapor, and particulates, a special <span class="hlt">air</span> inlet probe for <span class="hlt">sampling</span> outside <span class="hlt">air</span>, a computerized automatic control, and a data acquisition system. <span class="hlt">Air</span> constituents and related flight data are tape recorded in flight for later computer processing on the ground.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110007902','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110007902"><span>Eight Year Climatologies from Observational (<span class="hlt">AIRS</span>) and Model (MERRA) Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hearty, Thomas; Savtchenko, Andrey; Won, Young-In; Theobalk, Mike; Vollmer, Bruce; Manning, Evan; Smith, Peter; Ostrenga, Dana; Leptoukh, Greg</p> <p>2010-01-01</p> <p>We examine climatologies derived from eight years of temperature, water vapor, cloud, and trace gas observations made by the Atmospheric Infrared Sounder (<span class="hlt">AIRS</span>) instrument flying on the Aqua satellite and compare them to similar climatologies constructed with data from a global assimilation model, the Modern Era Retrospective-Analysis for Research and Applications (MERRA). We use the <span class="hlt">AIRS</span> climatologies to examine anomalies and trends in the <span class="hlt">AIRS</span> data record. Since <span class="hlt">sampling</span> can be an issue for infrared satellites in low earth orbit, we also use the MERRA data to examine the <span class="hlt">AIRS</span> <span class="hlt">sampling</span> biases. By <span class="hlt">sampling</span> the MERRA data at the <span class="hlt">AIRS</span> space-time locations both with and without the <span class="hlt">AIRS</span> quality control we estimate the <span class="hlt">sampling</span> bias of the <span class="hlt">AIRS</span> climatology and the atmospheric conditions where <span class="hlt">AIRS</span> has a lower <span class="hlt">sampling</span> rate. While the <span class="hlt">AIRS</span> temperature and water vapor <span class="hlt">sampling</span> biases are small at low latitudes, they can be more than a few degrees in temperature or 10 percent in water vapor at higher latitudes. The largest <span class="hlt">sampling</span> biases are over desert. The <span class="hlt">AIRS</span> and MERRA data are available from the Goddard Earth Sciences Data and Information Services Center (GES DISC). The <span class="hlt">AIRS</span> climatologies we used are available for analysis with the GIOVANNI data exploration tool. (see, http://disc.gsfc.nasa.gov).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29782003','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29782003"><span>Collection and Extraction of Occupational <span class="hlt">Air</span> <span class="hlt">Samples</span> for Analysis of Fungal DNA.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lemons, Angela R; Lindsley, William G; Green, Brett J</p> <p>2018-05-02</p> <p>Traditional methods of identifying fungal exposures in occupational environments, such as culture and microscopy-based approaches, have several limitations that have resulted in the exclusion of many species. Advances in the field over the last two decades have led occupational health researchers to turn to molecular-based approaches for identifying fungal hazards. These methods have resulted in the detection of many species within indoor and occupational environments that have not been detected using traditional methods. This protocol details an approach for determining fungal diversity within <span class="hlt">air</span> <span class="hlt">samples</span> through genomic DNA extraction, amplification, sequencing, and taxonomic identification of fungal internal transcribed spacer (ITS) regions. ITS sequencing results in the detection of many fungal species that are either not detected or difficult to identify to species level using culture or microscopy. While these methods do not provide quantitative measures of fungal burden, they offer a new approach to hazard identification and can be used to determine overall species richness and diversity within an occupational environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21016223-nonlinear-air-coupled-emission-signature-reveal-image-microdamage-solid-materials','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21016223-nonlinear-air-coupled-emission-signature-reveal-image-microdamage-solid-materials"><span>Nonlinear <span class="hlt">air</span>-coupled emission: The signature to <span class="hlt">reveal</span> and image microdamage in solid materials</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Solodov, Igor; Busse, Gerd</p> <p>2007-12-17</p> <p>It is shown that low-frequency elastic vibrations of near-surface planar defects cause high-frequency ultrasonic radiation in surrounding <span class="hlt">air</span>. The frequency conversion mechanism is concerned with contact nonlinearity of the defect vibrations and provides efficient generation of <span class="hlt">air</span>-coupled higher-order ultraharmonics, ultrasubharmonics, and combination frequencies. The nonlinear <span class="hlt">air</span>-coupled ultrasonic emission is applied for location and high-resolution imaging of damage-induced defects in a variety of solid materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26218073','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26218073"><span>Nullspace <span class="hlt">Sampling</span> with Holonomic Constraints <span class="hlt">Reveals</span> Molecular Mechanisms of Protein Gαs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pachov, Dimitar V; van den Bedem, Henry</p> <p>2015-07-01</p> <p>Proteins perform their function or interact with partners by exchanging between conformational substates on a wide range of spatiotemporal scales. Structurally characterizing these exchanges is challenging, both experimentally and computationally. Large, diffusional motions are often on timescales that are difficult to access with molecular dynamics simulations, especially for large proteins and their complexes. The low frequency modes of normal mode analysis (NMA) report on molecular fluctuations associated with biological activity. However, NMA is limited to a second order expansion about a minimum of the potential energy function, which limits opportunities to observe diffusional motions. By contrast, kino-geometric conformational <span class="hlt">sampling</span> (KGS) permits large perturbations while maintaining the exact geometry of explicit conformational constraints, such as hydrogen bonds. Here, we extend KGS and show that a conformational ensemble of the α subunit Gαs of heterotrimeric stimulatory protein Gs exhibits structural features implicated in its activation pathway. Activation of protein Gs by G protein-coupled receptors (GPCRs) is associated with GDP release and large conformational changes of its α-helical domain. Our method <span class="hlt">reveals</span> a coupled α-helical domain opening motion while, simultaneously, Gαs helix α5 <span class="hlt">samples</span> an activated conformation. These motions are moderated in the activated state. The motion centers on a dynamic hub near the nucleotide-binding site of Gαs, and radiates to helix α4. We find that comparative NMA-based ensembles underestimate the amplitudes of the motion. Additionally, the ensembles fall short in predicting the accepted direction of the full activation pathway. Taken together, our findings suggest that nullspace <span class="hlt">sampling</span> with explicit, holonomic constraints yields ensembles that illuminate molecular mechanisms involved in GDP release and protein Gs activation, and further establish conformational coupling between key structural</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4517867','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4517867"><span>Nullspace <span class="hlt">Sampling</span> with Holonomic Constraints <span class="hlt">Reveals</span> Molecular Mechanisms of Protein Gαs</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pachov, Dimitar V.; van den Bedem, Henry</p> <p>2015-01-01</p> <p>Proteins perform their function or interact with partners by exchanging between conformational substates on a wide range of spatiotemporal scales. Structurally characterizing these exchanges is challenging, both experimentally and computationally. Large, diffusional motions are often on timescales that are difficult to access with molecular dynamics simulations, especially for large proteins and their complexes. The low frequency modes of normal mode analysis (NMA) report on molecular fluctuations associated with biological activity. However, NMA is limited to a second order expansion about a minimum of the potential energy function, which limits opportunities to observe diffusional motions. By contrast, kino-geometric conformational <span class="hlt">sampling</span> (KGS) permits large perturbations while maintaining the exact geometry of explicit conformational constraints, such as hydrogen bonds. Here, we extend KGS and show that a conformational ensemble of the α subunit Gαs of heterotrimeric stimulatory protein Gs exhibits structural features implicated in its activation pathway. Activation of protein Gs by G protein-coupled receptors (GPCRs) is associated with GDP release and large conformational changes of its α-helical domain. Our method <span class="hlt">reveals</span> a coupled α-helical domain opening motion while, simultaneously, Gαs helix α5 <span class="hlt">samples</span> an activated conformation. These motions are moderated in the activated state. The motion centers on a dynamic hub near the nucleotide-binding site of Gαs, and radiates to helix α4. We find that comparative NMA-based ensembles underestimate the amplitudes of the motion. Additionally, the ensembles fall short in predicting the accepted direction of the full activation pathway. Taken together, our findings suggest that nullspace <span class="hlt">sampling</span> with explicit, holonomic constraints yields ensembles that illuminate molecular mechanisms involved in GDP release and protein Gs activation, and further establish conformational coupling between key structural</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApSS..416..168B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApSS..416..168B"><span>Effect of dry <span class="hlt">air</span> on interface smoothening in reactive sputter deposited Co/Ti multilayer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Biswas, A.; Porwal, A.; Bhattacharya, Debarati; Prajapat, C. L.; Ghosh, Arnab; Nand, Mangla; Nayak, C.; Rai, S.; Jha, S. N.; Singh, M. R.; Bhattacharyya, D.; Basu, S.; Sahoo, N. K.</p> <p>2017-09-01</p> <p>Top surface roughness and interface roughness are one of the key elements which determine the performance of X-ray and neutron thin film multilayer devices. It has been observed that by mixing <span class="hlt">air</span> with argon in sputtering ambience during deposition of Co layers, polarized neutron reflectivity (PNR) of Co/Ti supermirror polarizers can be improved substantially. Cross-sectional HRTEM measurement <span class="hlt">reveals</span> that sharper interfaces in the supermirror can be achieved in case of deposition of the multilayer under mixed ambience of argon and <span class="hlt">air</span>. In order to investigate this interface modification mechanism further, in this communication two sets of tri-layer Co/Ti/Co <span class="hlt">samples</span> and 20-layer Co/Ti periodic multilayer <span class="hlt">samples</span> have been prepared; in one set all the layers are deposited only under argon ambience and in the other set, Co layers are deposited under a mixed ambience of argon and <span class="hlt">air</span>. These <span class="hlt">samples</span> have been characterized by measuring specular and non-specular X-ray reflectivities (GIXR) with X-rays of 1.54 Å wavelength and polarized neutron reflectivity (PNR) with neutron of 2.5 Å wavelength at grazing angle of incidence. It has been observed that the X-ray and neutron specular reflectivities at Bragg peaks of 20 layer periodic multilayer increase when Co layers are deposited under mixed ambience of argon and <span class="hlt">air</span>. The detail information regarding the effect of <span class="hlt">air</span> on the interfaces and magnetic properties has been obtained by fitting the measured spectra. The above information has subsequently been supplemented by XRD and magnetic measurements on the <span class="hlt">samples</span>. XPS and XANES measurements have also been carried out to investigate whether cobalt oxide or cobalt nitride layers are being formed due to use of <span class="hlt">air</span> in sputtering ambience.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20205382','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20205382"><span>Dynamic planar solid phase microextraction-ion mobility spectrometry for rapid field <span class="hlt">air</span> <span class="hlt">sampling</span> and analysis of illicit drugs and explosives.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guerra-Diaz, Patricia; Gura, Sigalit; Almirall, José R</p> <p>2010-04-01</p> <p>A preconcentration device that targets the volatile chemical signatures associated with illicit drugs and explosives (high and low) has been designed to fit in the inlet of an ion mobility spectrometer (IMS). This is the first reporting of a fast and sensitive method for dynamic <span class="hlt">sampling</span> of large volumes of <span class="hlt">air</span> using planar solid phase microextraction (PSPME) incorporating a high surface area for absorption of analytes onto a sol-gel polydimethylsiloxane (PDMS) coating for direct thermal desorption into an IMS. This device affords high extraction efficiencies due to strong retention properties at ambient temperature, resulting in the detection of analyte concentrations in the parts per trillion range when as low as 3.5 L of <span class="hlt">air</span> are <span class="hlt">sampled</span> over the course of 10 s (absolute mass detection of less than a nanogram). Dynamic PSPME was used to <span class="hlt">sample</span> the headspace over the following: 3,4-methylenedioxymethamphetamine (MDMA) tablets resulting in the detection of 12-40 ng of piperonal, high explosives (Pentolite) resulting in the detection of 0.6 ng of 2,4,6-trinitrotoluene (TNT), and low explosives (several smokeless powders) resulting in the detection of 26-35 ng of 2,4-dinitrotoluene (2,4-DNT) and 11-74 ng of diphenylamine (DPA).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12855489','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12855489"><span>Analysis of particle and vapour phase PAHs from the personal <span class="hlt">air</span> <span class="hlt">samples</span> of bus garage workers exposed to diesel exhaust.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kuusimaki, Leea; Peltonen, Kimmo; Mutanen, Pertti; Savela, Kirsti</p> <p>2003-07-01</p> <p>The levels of particle and vapour phase polycyclic aromatic hydrocarbons (PAHs) derived from the diesel exhaust compounds in bus garage work were measured in winter and in summer. Five personal <span class="hlt">air</span> <span class="hlt">samples</span> were collected from the breathing zones of 22 garage workers every other day of consecutive weeks. Control <span class="hlt">samples</span> (n = 22) were collected from office workers in Helsinki. Fifteen PAHs in the <span class="hlt">air</span> <span class="hlt">samples</span> were analysed by HPLC using a fluorescence detector. Statistically significant differences were observed between total PAH levels of the exposed workers (2241 and 1245 ng/m(3)) and the control group (254 and 275 ng/m(3)) in both winter (P < 0.001) and summer (P < 0.001). Phenanthrene, pyrene, benzo[ghi]perylene and fluoranthene were the major compounds in the particle phase, and naphthalene, phenanthrene and fluorene in the vapour phase. About 98% of PAHs measured were related to the vapour phase compounds, whereas the high molecular weight PAH compounds were detected only in the particle phase. The PAH levels in the garages were twice as high (P < 0.001) in winter as in summer. Even though the exposure levels were low in the bus garages, the low level does not allow conclusions to be drawn about the possible adverse health effects due to exposure to diesel exhaust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760042997&hterms=sampling+distribution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsampling%2Bdistribution','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760042997&hterms=sampling+distribution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsampling%2Bdistribution"><span>An automated atmospheric <span class="hlt">sampling</span> system operating on 747 airliners</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Perkins, P. J.; Gustafsson, U. R. C.</p> <p>1976-01-01</p> <p>An <span class="hlt">air</span> <span class="hlt">sampling</span> system that automatically measures the temporal and spatial distribution of particulate and gaseous constituents of the atmosphere is collecting data on commercial <span class="hlt">air</span> routes covering the world. Measurements are made in the upper troposphere and lower stratosphere (6 to 12 km) of constituents related to aircraft engine emissions and other pollutants. Aircraft operated by different airlines <span class="hlt">sample</span> <span class="hlt">air</span> at latitudes from the Arctic to Australia. This unique system includes specialized instrumentation, a special <span class="hlt">air</span> inlet probe for <span class="hlt">sampling</span> outside <span class="hlt">air</span>, a computerized automatic control, and a data acquisition system. <span class="hlt">Air</span> constituent and related flight data are tape recorded in flight for later computer processing on the ground.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27382727','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27382727"><span>[Determination of short-chain chlorinated paraffins in ambient <span class="hlt">air</span> using high-volume <span class="hlt">sampling</span> combined with high resolutimi gas chromatography-electron capture negative ion-low resolution mass spectrometry].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shi, Loimeng; Gao, Yuan; Hou, Xiaohong; Zhang, Haijun; Zhang, Yichi; Chen, Jiping</p> <p>2016-02-01</p> <p>An analytical method for quantifying short-chain chlorinated paraffins (SCCPs) in ambient <span class="hlt">air</span> using high-volume <span class="hlt">sampling</span> combined with high resolution gas chromatography-electron capture negative ion-low resolution mass spectrometry ( HRGC-ECNI-LRMS) was developed. An acidified silica gel column and a basic alumina column were used to optimize the cleanup procedures. The results showed a good linearity (R2>0. 99) between the total response factors and the degree of chlorination of SCCPs in the content range of 58. 1%-63. 3%. The limits of detection (S/N ≥3) and the limits of quantification (S/N ≥ 10) were 4. 2 and 12 µg, respectively. The method detection limit (MDL) for SCCPs was 0. 34 ng/m3 (n = 7). The recoveries of SCCPs in <span class="hlt">air</span> <span class="hlt">samples</span> were in the range of 81. 9% to 94. 2%. It is demonstrated that the method is suitable for the quantitative analysis of SCCPs in <span class="hlt">air</span> <span class="hlt">samples</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25752138','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25752138"><span>[Restoration of microbial ammonia oxidizers in <span class="hlt">air</span>-dried forest soils upon wetting].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Xue; Huang, Rong; Song, Ge; Pan, Xianzhang; Jia, Zhongjun</p> <p>2014-11-04</p> <p>This study was aimed to investigate the abundance and community shift of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in <span class="hlt">air</span>-dried forest soils in response to water addition, to explore the applicability of <span class="hlt">air</span>-dried soil for microbial ecology study, and to elucidate whether AOA within the marine group 1. 1a dominate ammonia oxidizers communities in the acidic forest soils in China. Soil <span class="hlt">samples</span> were collected from 10 forest sites of the China Ecosystem Research Network (CERN) and kept under <span class="hlt">air</span>-drying conditions in 2010. In 2013 the <span class="hlt">air</span>-dried soil <span class="hlt">samples</span> were adjusted to 60% of soil maximum water holding capacity for a 28-day incubation at 28 degrees C in darkness. DGGE fingerprinting, clone library construction, pyrosequencing and quantitative PCR of amoA genes were performed to assess community change of ammonia oxidizers in <span class="hlt">air</span>-dried and re-wetted soils. After incubation for 28 days, the abundance of bacteria and archaea increased significantly, up to 3,230 and 568 times, respectively. AOA increased significantly in 8 <span class="hlt">samples</span>, and AOB increased significantly in 5 of 10 <span class="hlt">samples</span>. However, pyrosequencing of amoA genes <span class="hlt">reveals</span> insignificant changes in composition of AOA and AOB communities. Phylogenetic analysis of amoA genes indicates that archaeal ammonia oxidizers were predominated by AOA within the soil group 1. 1b lineage, while the Nitrosospira-like AOB dominate bacteria ammonia oxidizer communities. There was a significantly positive correlation between AOA/AOB ratio and total nitrogen (r2 = 0.54, P < 0.05), implying that soil ammonia oxidation might be dominated by AOA in association with ammonium released from soil mineralization. Phylogenetic analysis suggest that AOA members within the soil group 1. 1b lineage were not restricted to non-acidic soils as previously thought. The abundance rather than composition of AOA and AOB changed in response to water addition. This indicates that <span class="hlt">air</span>-dried soil could be of help for microbial biogeography study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16361218','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16361218"><span>An evaluation of analytical methods, <span class="hlt">air</span> <span class="hlt">sampling</span> techniques, and airborne occupational exposure of metalworking fluids.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Verma, Dave K; Shaw, Don S; Shaw, M Lorraine; Julian, Jim A; McCollin, Shari-Ann; des Tombe, Karen</p> <p>2006-02-01</p> <p>This article summarizes an assessment of <span class="hlt">air</span> <span class="hlt">sampling</span> and analytical methods for both oil and water-based metalworking fluids (MWFs). Three hundred and seventy-four long-term area and personal airborne <span class="hlt">samples</span> were collected at four plants using total (closed-face) aerosol samplers and thoracic samplers. A direct-reading device (DustTrak) was also used. The processes <span class="hlt">sampled</span> include steel tube making, automotive component manufacturing, and small part manufacturing in a machine shop. The American Society for Testing and Materials (ASTM) Method PS42-97 of analysis was evaluated in the laboratory. This evaluation included <span class="hlt">sample</span> recovery, determination of detection limits, and stability of <span class="hlt">samples</span> during storage. Results of the laboratory validation showed (a) the <span class="hlt">sample</span> recovery to be about 87%, (b) the detection limit to be 35 microg, and (c) <span class="hlt">sample</span> stability during storage at room temperature to decline rapidly within a few days. To minimize <span class="hlt">sample</span> loss, the <span class="hlt">samples</span> should be stored in a freezer and analyzed within a week. The ASTM method should be the preferred method for assessing metalworking fluids (MWFs). The ratio of thoracic aerosol to total aerosol ranged from 0.6 to 0.7. A similar relationship was found between the thoracic extractable aerosol and total extractable aerosol. The DustTrak, with 10-microm <span class="hlt">sampling</span> head, was useful in pinpointing the areas of potential exposure. MWF exposure at the four plants ranged from 0.04 to 3.84 mg/m3 with the geometric mean ranging between 0.22 to 0.59 mg/m3. Based on this data and the assumption of log normality, MWF exposures are expected to exceed the National Institute for Occupational Safety and Health recommended exposure limit of 0.5 mg/m3 as total mass and 0.4 mg/m3 as thoracic mass about 38% of the time. In addition to controlling airborne MWF exposure, full protection of workers would require the institution of programs for fluid management and dermal exposure prevention.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21111140','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21111140"><span>Simultaneous determination of hydroquinone, resorcinol, phenol, m-cresol and p-cresol in untreated <span class="hlt">air</span> <span class="hlt">samples</span> using spectrofluorimetry and a custom multiple linear regression-successive projection algorithm.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pistonesi, Marcelo F; Di Nezio, María S; Centurión, María E; Lista, Adriana G; Fragoso, Wallace D; Pontes, Márcio J C; Araújo, Mário C U; Band, Beatriz S Fernández</p> <p>2010-12-15</p> <p>In this study, a novel, simple, and efficient spectrofluorimetric method to determine directly and simultaneously five phenolic compounds (hydroquinone, resorcinol, phenol, m-cresol and p-cresol) in <span class="hlt">air</span> <span class="hlt">samples</span> is presented. For this purpose, variable selection by the successive projections algorithm (SPA) is used in order to obtain simple multiple linear regression (MLR) models based on a small subset of wavelengths. For comparison, partial least square (PLS) regression is also employed in full-spectrum. The concentrations of the calibration matrix ranged from 0.02 to 0.2 mg L(-1) for hydroquinone, from 0.05 to 0.6 mg L(-1) for resorcinol, and from 0.05 to 0.4 mg L(-1) for phenol, m-cresol and p-cresol; incidentally, such ranges are in accordance with the Argentinean environmental legislation. To verify the accuracy of the proposed method a recovery study on real <span class="hlt">air</span> <span class="hlt">samples</span> of smoking environment was carried out with satisfactory results (94-104%). The advantage of the proposed method is that it requires only spectrofluorimetric measurements of <span class="hlt">samples</span> and chemometric modeling for simultaneous determination of five phenols. With it, <span class="hlt">air</span> is simply <span class="hlt">sampled</span> and no pre-treatment <span class="hlt">sample</span> is needed (i.e., separation steps and derivatization reagents are avoided) that means a great saving of time. Copyright © 2010 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28000117','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28000117"><span>Monitoring Indoor <span class="hlt">Air</span> Quality for Enhanced Occupational Health.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pitarma, Rui; Marques, Gonçalo; Ferreira, Bárbara Roque</p> <p>2017-02-01</p> <p>Indoor environments are characterized by several pollutant sources. Because people spend more than 90% of their time in indoor environments, several studies have pointed out the impact of indoor <span class="hlt">air</span> quality on the etiopathogenesis of a wide number of non-specific symptoms which characterizes the "Sick Building Syndrome", involving the skin, the upper and lower respiratory tract, the eyes and the nervous system, as well as many building related diseases. Thus, indoor <span class="hlt">air</span> quality (IAQ) is recognized as an important factor to be controlled for the occupants' health and comfort. The majority of the monitoring systems presently available is very expensive and only allow to collect random <span class="hlt">samples</span>. This work describes the system (iAQ), a low-cost indoor <span class="hlt">air</span> quality monitoring wireless sensor network system, developed using Arduino, XBee modules and micro sensors, for storage and availability of monitoring data on a web portal in real time. Five micro sensors of environmental parameters (<span class="hlt">air</span> temperature, humidity, carbon monoxide, carbon dioxide and luminosity) were used. Other sensors can be added for monitoring specific pollutants. The results <span class="hlt">reveal</span> that the system can provide an effective indoor <span class="hlt">air</span> quality assessment to prevent exposure risk. In fact, the indoor <span class="hlt">air</span> quality may be extremely different compared to what is expected for a quality living environment. Systems like this would have benefit as public health interventions to reduce the burden of symptoms and diseases related to "sick buildings".</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=23098&Lab=NERL&keyword=descriptive+AND+survey+AND+design&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=23098&Lab=NERL&keyword=descriptive+AND+survey+AND+design&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR EXTRACTION OF <span class="hlt">AIR</span> <span class="hlt">SAMPLES</span> FOR GC/MS ANALYSIS OF PESTICIDE AND PAH (BCO-L-27.0)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The purpose of this SOP is to describe methods for extracting and preparing an <span class="hlt">air</span> <span class="hlt">sample</span> consisting of a quartz fiber filter (Pallflex) and an XAD-2 cartridge for analysis of pesticides and polyaromatic hydrocarbons (PAHs). It covers the preparation of <span class="hlt">samples</span> that are to be an...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25859937','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25859937"><span>Ambient <span class="hlt">air</span> particulates and particulate-bound mercury Hg(p) concentrations: dry deposition study over a Traffic, Airport, Park (T.A.P.) areas during years of 2011-2012.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fang, Guor-Cheng; Lin, Yen-Heng; Zheng, Yu-Cheng</p> <p>2016-02-01</p> <p>The main purpose of this study was to monitor ambient <span class="hlt">air</span> particles and particulate-bound mercury Hg(p) in total suspended particulate (TSP) concentrations and dry deposition at the Hung Kuang (Traffic), Taichung airport and Westing Park <span class="hlt">sampling</span> sites during the daytime and nighttime, from 2011 to 2012. In addition, the calculated/measured dry deposition flux ratios of ambient <span class="hlt">air</span> particles and particulate-bound mercury Hg(p) were also studied with Baklanov & Sorensen and the Williams models. For a particle size of 10 μm, the Baklanov & Sorensen model yielded better predictions of dry deposition of ambient <span class="hlt">air</span> particulates and particulate-bound mercury Hg(p) at the Hung Kuang (Traffic), Taichung airport and Westing Park <span class="hlt">sampling</span> site during the daytime and nighttime <span class="hlt">sampling</span> periods. However, for particulates with sizes 20-23 μm, the results obtained in the study <span class="hlt">reveal</span> that the Williams model provided better prediction results for ambient <span class="hlt">air</span> particulates and particulate-bound mercury Hg(p) at all <span class="hlt">sampling</span> sites in this study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=159846&keyword=end+AND+world&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=159846&keyword=end+AND+world&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>RELATIVE CONGENER SCALING OF POLYCHLORINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS TO ESTIMATE BUILDING FIRE CONTRIBUTIONS IN <span class="hlt">AIR</span>, SURFACE WIPES, AND DUST <span class="hlt">SAMPLES</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>EPA collected ambient <span class="hlt">air</span> <span class="hlt">samples</span> in lower Manhattan for about nine months following the September 11, 2001 (9/11) World Trade Center (WTC) attacks. Measurements were made of a host of airborne contaminants including volatile organic compounds (VOCs), polycyclic aromatic hydroca...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=213282&Lab=NRMRL&keyword=technical+AND+training&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=213282&Lab=NRMRL&keyword=technical+AND+training&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span><span class="hlt">Air</span>-Based Remediation Workshop - Section 1 <span class="hlt">Sampling</span> And Analysis Revelant To <span class="hlt">Air</span>-Based Remediation Technologies</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Pursant to the EPA-AIT Implementing Arrangement 7 for Technical Environmental Collaboration, Activity 11 "Remediation of Contaminated Sites," the USEPA Office of International Affairs Organized a Force <span class="hlt">Air</span> Remediation Workshop in Taipei to deliver expert training to the Environme...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750011551','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750011551"><span>Development and testing of a portable wind sensitive directional <span class="hlt">air</span> sampler</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deyo, J.; Toma, J.; King, R. B.</p> <p>1975-01-01</p> <p>A portable wind sensitive directional <span class="hlt">air</span> sampler was developed as part of an <span class="hlt">air</span> pollution source identification system. The system is designed to identify sources of <span class="hlt">air</span> pollution based on the directional collection of field <span class="hlt">air</span> <span class="hlt">samples</span> and their analysis for TSP and trace element characteristics. Sources can be identified by analyzing the data on the basis of pattern recognition concepts. The unit, designated <span class="hlt">Air</span> Scout, receives wind direction signals from an associated wind vane. <span class="hlt">Air</span> <span class="hlt">samples</span> are collected on filter slides using a standard high volume <span class="hlt">air</span> sampler drawing <span class="hlt">air</span> through a porting arrangement which tracks the wind direction and permits collection of discrete <span class="hlt">samples</span>. A preset timer controls the length of time each filter is in the <span class="hlt">sampling</span> position. At the conclusion of the <span class="hlt">sampling</span> period a new filter is automatically moved into <span class="hlt">sampling</span> position displacing the previous filter to a storage compartment. Thus the <span class="hlt">Air</span> Scout may be set up at a field location, loaded with up to 12 filter slides, and left to acquire <span class="hlt">air</span> <span class="hlt">samples</span> automatically, according to the wind, at any timer interval desired from 1 to 30 hours.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A41J..05M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A41J..05M"><span>The value and limitations of global <span class="hlt">air-sampling</span> networks for improving our understanding trace gas behavior</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Montzka, S. A.</p> <p>2016-12-01</p> <p>Measurements from global surface-based <span class="hlt">air</span> <span class="hlt">sampling</span> networks provide a fundamental understanding of how and why concentrations of long-lived trace gases are changing over time. Results from these networks are used to quantify trace-gas concentrations and their time-dependent changes on global and smaller scales, and thus provide a means to quantify emission rates, loss frequencies, and mixing processes. Substantial advances in measurement and <span class="hlt">sampling</span> technologies and the ability of these programs to create and maintain reliable gas standards mean that spatial concentration gradients and time-dependent changes are often very reliably measured. The presence of multiple independent networks allows an assessment of this reliability. Furthermore, recent global `snap-shot' surveys (e.g., HIPPO and ATom) and ongoing atmospheric profiling programs help us assess the ability of surface-based data to describe concentration distributions throughout most of the atmosphere ( 80% of its mass). In this overview talk, I'll explore the usefulness and limitations of existing long-term, ongoing <span class="hlt">sampling</span> network programs and their advantages and disadvantages for characterizing concentrations on global and regional scales, and how recent advances (and short-term <span class="hlt">sampling</span> programs) help us assess the accuracy of the surface networks to provide estimates of source and sink magnitudes, and inter-annual variability in both.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1911068C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1911068C"><span>Aerial <span class="hlt">sampling</span> using drones for measuring trace gases</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Chih-Chung; Wang, Jia-Lin; Chang, Chih-Yuan; Lin, Ming-Ren; Ou-Yang, Chang-Feng; Pan, Xiang-Xu; Lin, Neng-Huei</p> <p>2017-04-01</p> <p>Aerial and ground-level <span class="hlt">samples</span> were simultaneously collected at the northern tip of Taiwan, Cape Fuguei, which is commonly served as a receptor site to receive <span class="hlt">air</span> parcels from East Asia, Asian continent, the northwest Pacific Ocean and the island of Taiwan itself. Both aerial and surface <span class="hlt">samples</span> were analyzed for 106 volatile organic compounds (VOCs) and divided into three categories as follows: 1. the total concentrations of 106 VOC (T-VOC) at 300-m height that are lower than the T-VOC level at the surface (Category A), 2. T-VOC concentrations at 300-m that are higher than those at the surface (Category B), and 3. comparable concentrations (Category C). Ten VOCs were exploited as tracers for a variety of emission sources linking to possible sources and transport routes of airborne pollutants. The first two categories A and B showed significant differences in the observed composition and concentrations of tracers between aerial and ground-level <span class="hlt">samples</span>, implying that the pollutants at different heights may have resulted from different sources and poor <span class="hlt">air</span> mixing, despite only a 300-m difference in vertical height. In contrast, Category C showed good vertical mixing, as indicated by the comparable concentrations between the aerial and surface measurements. Since the three categories occurred in specific meteorological conditions (between, prior to, and after cold fronts), respectively, it suggests that varied prevailing meteorology controlled the distribution and transport of airborne pollutants. Unlike <span class="hlt">sampling</span> commonly performed at the surface, this study uses aerial <span class="hlt">sampling</span> to demonstrate that layered structures under different meteorological conditions. <span class="hlt">Sampling</span> aloft in lower boundary layer avoids <span class="hlt">samples</span> being over-influenced by the close-by surface sources such as traffic to <span class="hlt">reveal</span> signatures of a broader region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3710735','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3710735"><span>Inter-conversion of Chromium Species During <span class="hlt">Air</span> <span class="hlt">Sampling</span>: Effects of O3, NO2, SO2, Particle Matrices, Temperature and Humidity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Huang, Lihui; Fan, Zhihua (Tina); Yu, Chang Ho; Hopke, Philip K.; Lioy, Paul J.; Buckley, Brian T.; Lin, Lin; Ma, Yingjun</p> <p>2013-01-01</p> <p>The inter-conversion between Cr(VI), a pulmonary carcinogen, and Cr(III), an essential human nutrient, poses challenges to the measurement of Cr(VI) in airborne particles. Chamber and field tests were conducted to identify the factors affecting Cr(VI)-Cr(III) inter-conversion in the basic filter medium under typical <span class="hlt">sampling</span> conditions. In the chamber tests, isotopically enriched 53Cr(VI) and 50Cr(III) were spiked on diesel particulate matter (DPM) and secondary organic aerosol (SOA) that were pre-collected on a basic MCE filter. The filter <span class="hlt">samples</span> were then exposed to clean <span class="hlt">air</span> or the <span class="hlt">air</span> containing SO2 (50 and 160 ppb), 100 ppb O3, or 150 ppb NO2 for 24 hours at 16.7 LPM flow rate at designated temperature (20 and 31°C) and RH (40% and 70%) conditions. Exposure to 160 ppb SO2 had the greatest effect on 53Cr(VI) reduction, with 53Cr(VI) recovery of 31.7 ± 15.8% (DPM) and 42.0 ± 7.9% (SOA). DPM and SOA matrix induced 53Cr(VI) reduction when exposed to clean <span class="hlt">air</span> while reactive oxygen species in SOA could promote 50Cr(III) oxidation. Deliquescence when RH increased from 40% to 70% led to conversion of Cr(III) in SOA, whereas oxidized organics in DPM and SOA enhanced hygroscopicity and thus facilitated Cr(VI) reduction. Field tests showed seasonal variation of Cr(VI)-Cr(III) inter-conversion during <span class="hlt">sampling</span>. Correction of the inter-conversion using USEPA method 6800 is recommended to improve accuracy of ambient Cr(VI) measurements. PMID:23550818</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-NHQ_2016_0909_TWAN.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-NHQ_2016_0909_TWAN.html"><span>Asteroid <span class="hlt">Sample</span> Return Mission Launches on This Week @NASA – September 9, 2016</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2016-09-09</p> <p>On Sept. 8, NASA launched the Origins, Spectral Interpretation, Resource Identification, Security - Regolith Explorer, or OSIRIS-REx mission from Cape Canaveral <span class="hlt">Air</span> Force Station in Florida. OSIRIS-REx, the first U.S. mission to <span class="hlt">sample</span> an asteroid, is scheduled to arrive at near-Earth asteroid Bennu in 2018. Mission plans call for the spacecraft to survey the asteroid, retrieve a small <span class="hlt">sample</span> from its surface, and return the <span class="hlt">sample</span> to Earth for study in 2023. Analysis of that <span class="hlt">sample</span> is expected to <span class="hlt">reveal</span> clues about the history of Bennu over the past 4.5 billion years, as well as clues about the evolution of our solar system. Also, Jeff Williams’ Record-Breaking Spaceflight Concludes, Next ISS Crew Prepares for Launch, <span class="hlt">Sample</span> Return Robot Challenge, NASA X-Plane Gets its Wing, and Convergent Aeronautics Solutions Showcase!</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B33D2106Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B33D2106Z"><span>Repeat synoptic <span class="hlt">sampling</span> <span class="hlt">reveals</span> drivers of change in carbon and nutrient chemistry of Arctic catchments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zarnetske, J. P.; Abbott, B. W.; Bowden, W. B.; Iannucci, F.; Griffin, N.; Parker, S.; Pinay, G.; Aanderud, Z.</p> <p>2017-12-01</p> <p>Dissolved organic carbon (DOC), nutrients, and other solute concentrations are increasing in rivers across the Arctic. Two hypotheses have been proposed to explain these trends: 1. distributed, top-down permafrost degradation, and 2. discrete, point-source delivery of DOC and nutrients from permafrost collapse features (thermokarst). While long-term monitoring at a single station cannot discriminate between these mechanisms, synoptic <span class="hlt">sampling</span> of multiple points in the stream network could <span class="hlt">reveal</span> the spatial structure of solute sources. In this context, we <span class="hlt">sampled</span> carbon and nutrient chemistry three times over two years in 119 subcatchments of three distinct Arctic catchments (North Slope, Alaska). Subcatchments ranged from 0.1 to 80 km2, and included three distinct types of Arctic landscapes - mountainous, tundra, and glacial-lake catchments. We quantified the stability of spatial patterns in synoptic water chemistry and analyzed high-frequency time series from the catchment outlets across the thaw season to identify source areas for DOC, nutrients, and major ions. We found that variance in solute concentrations between subcatchments collapsed at spatial scales between 1 to 20 km2, indicating a continuum of diffuse- and point-source dynamics, depending on solute and catchment characteristics (e.g. reactivity, topography, vegetation, surficial geology). Spatially-distributed mass balance <span class="hlt">revealed</span> conservative transport of DOC and nitrogen, and indicates there may be strong in-stream retention of phosphorus, providing a network-scale confirmation of previous reach-scale studies in these Arctic catchments. Overall, we present new approaches to analyzing synoptic data for change detection and quantification of ecohydrological mechanisms in ecosystems in the Arctic and beyond.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120007439','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120007439"><span>Surface, Water, and <span class="hlt">Air</span> Biocharacterization (SWAB) Flight Experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Castro, V. A.; Ott, C. M.; Pierson, D. L.</p> <p>2012-01-01</p> <p>The determination of risk from infectious disease during spaceflight missions is composed of several factors including both the concentration and characteristics of the microorganisms to which the crew are exposed. Thus, having a good understanding of the microbial ecology aboard spacecraft provides the necessary information to mitigate health risks to the crew. While preventive measures are taken to minimize the presence of pathogens on spacecraft, medically significant organisms have been isolated from both the Mir and International Space Station (ISS). Historically, the method for isolation and identification of microorganisms from spacecraft environmental <span class="hlt">samples</span> depended upon their growth on culture media. Unfortunately, only a fraction of the organisms may grow on a specific culture medium, potentially omitting those microorganisms whose nutritional and physical requirements for growth are not met. To address this bias in our understanding of the ISS environment, the Surface, Water, and <span class="hlt">Air</span> Biocharacterization (SWAB) Flight Experiment was designed to investigate and develop monitoring technology to provide better microbial characterization. For the SWAB flight experiment, we hypothesized that environmental analysis using non-culture-based technologies would <span class="hlt">reveal</span> microorganisms, allergens, and microbial toxins not previously reported in spacecraft, allowing for a more complete health assessment. Key findings during this experiment included: a) Generally, advanced molecular techniques were able to <span class="hlt">reveal</span> a few organisms not recovered using culture-based methods; however, there is no indication that current monitoring is "missing" any medically significant bacteria or fungi. b) Molecular techniques have tremendous potential for microbial monitoring, however, <span class="hlt">sample</span> preparation and data analysis present challenges for spaceflight hardware. c) Analytical results indicate that some molecular techniques, such as denaturing gradient gel electrophoresis (DGGE), can</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3949983','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3949983"><span>Stable Isotope Analysis of Precipitation <span class="hlt">Samples</span> Obtained via Crowdsourcing <span class="hlt">Reveals</span> the Spatiotemporal Evolution of Superstorm Sandy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Good, Stephen P.; Mallia, Derek V.; Lin, John C.; Bowen, Gabriel J.</p> <p>2014-01-01</p> <p>Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation <span class="hlt">samples</span> to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic <span class="hlt">sampling</span> of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (21‰ for O, 160‰ for H) and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (25‰) were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these <span class="hlt">samples</span> reflect the moistening of dry continental <span class="hlt">air</span> entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies. PMID:24618882</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=48052&Lab=NERL&keyword=batteries&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=48052&Lab=NERL&keyword=batteries&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>A BATTERY-OPERATED <span class="hlt">AIR</span> SAMPLER FOR REMOTE AREAS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>An <span class="hlt">air</span> <span class="hlt">sampling</span> system developed to evaluate <span class="hlt">air</span> quality in biosphere reserves or in other remote areas is described. The equipment consists of a Dupont P-4000 pump and a specially designed battery pack containing Gates batteries. This <span class="hlt">air</span> <span class="hlt">sampling</span> system was tested in Southern U...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19485204','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19485204"><span>Validation of a modification to Performance-Tested Method 070601: <span class="hlt">Reveal</span> Listeria Test for detection of Listeria spp. in selected foods and selected environmental <span class="hlt">samples</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alles, Susan; Peng, Linda X; Mozola, Mark A</p> <p>2009-01-01</p> <p>A modification to Performance-Tested Method (PTM) 070601, <span class="hlt">Reveal</span> Listeria Test (<span class="hlt">Reveal</span>), is described. The modified method uses a new media formulation, LESS enrichment broth, in single-step enrichment protocols for both foods and environmental sponge and swab <span class="hlt">samples</span>. Food <span class="hlt">samples</span> are enriched for 27-30 h at 30 degrees C and environmental <span class="hlt">samples</span> for 24-48 h at 30 degrees C. Implementation of these abbreviated enrichment procedures allows test results to be obtained on a next-day basis. In testing of 14 food types in internal comparative studies with inoculated <span class="hlt">samples</span>, there was a statistically significant difference in performance between the <span class="hlt">Reveal</span> and reference culture [U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA/BAM) or U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS)] methods for only a single food in one trial (pasteurized crab meat) at the 27 h enrichment time point, with more positive results obtained with the FDA/BAM reference method. No foods showed statistically significant differences in method performance at the 30 h time point. Independent laboratory testing of 3 foods again produced a statistically significant difference in results for crab meat at the 27 h time point; otherwise results of the <span class="hlt">Reveal</span> and reference methods were statistically equivalent. Overall, considering both internal and independent laboratory trials, sensitivity of the <span class="hlt">Reveal</span> method relative to the reference culture procedures in testing of foods was 85.9% at 27 h and 97.1% at 30 h. Results from 5 environmental surfaces inoculated with various strains of Listeria spp. showed that the <span class="hlt">Reveal</span> method was more productive than the reference USDA-FSIS culture procedure for 3 surfaces (stainless steel, plastic, and cast iron), whereas results were statistically equivalent to the reference method for the other 2 surfaces (ceramic tile and sealed concrete). An independent laboratory trial with ceramic tile inoculated with L</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29270680','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29270680"><span>Saharan dust particles in snow <span class="hlt">samples</span> of Alps and Apennines during an exceptional event of transboundary <span class="hlt">air</span> pollution.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Telloli, Chiara; Chicca, Milvia; Pepi, Salvatore; Vaccaro, Carmela</p> <p>2017-12-21</p> <p>Southern European countries are often affected in summer by transboundary <span class="hlt">air</span> pollution from Saharan dust. However, very few studies deal with Saharan dust pollution at high altitudes in winter. In Italy, the exceptional event occurred on February 19, 2014, colored in red the entire mountain range (Alps and Apennines) and allowed to characterize the particulate matter deposited on snow from a morphological and chemical point of view. Snow <span class="hlt">samples</span> were collected after this event in four areas in the Alps and one in the Apennines. The particulate matter of the melted snow <span class="hlt">samples</span> was analyzed by scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS) and by inductively coupled plasma mass spectrometry (ICP-MS). These analyses confirmed the presence of Saharan dust particle components in all areas with similar percentages, supported also by the positive correlations between Mg-Ca, Al-Ca, Al-Mg, and Al-K in all <span class="hlt">samples</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25563832','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25563832"><span>Impact of fine particulate fluctuation and other variables on Beijing's <span class="hlt">air</span> quality index.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Bo; Lu, Shaowei; Li, Shaoning; Wang, Bing</p> <p>2015-04-01</p> <p>We analyzed fluctuation in Beijing's <span class="hlt">air</span> quality over 328 days, based on <span class="hlt">air</span> quality grades and <span class="hlt">air</span> quality data from 35 atmospheric monitoring stations. Our results show the <span class="hlt">air</span> over Beijing is subject to pollution 152 days of the year, or 46.34%. Among all pollutants, fine particulates, solid or liquid, 2.5 μm or less in size (PM2.5), appeared most frequently as the primary pollutant: 249 days, or 76% of the <span class="hlt">sample</span> year (328 days). Nitrogen dioxide (NO2) and coarse particulates (PM10) cause the least pollution, appearing only 7 and 3 days, or 2 and 1% of the <span class="hlt">sample</span> year, respectively. In Beijing, fine particulates like PM2.5 vary seasonally: 154.54 ± 18.60 in winter > 145.22 ± 18.61 in spring > 140.16 ± 20.76 in autumn > 122.37 ± 13.42 in summer. <span class="hlt">Air</span> quality is best in August and worst in December, while various districts in Beijing experience different <span class="hlt">air</span> quality. To be specific, from south to north and from west to east, <span class="hlt">air</span> quality tends to improve. Meteorological elements have a constraining effect on <span class="hlt">air</span> pollutants, which means there is a linear correlation between the <span class="hlt">air</span> quality index and humidity, rainfall, wind speed, and temperature. Under a typical pollution scenario, the higher the <span class="hlt">air</span> quality index (AQI) value, the lower the wind speed and the greater the relative humidity; the lower the AQI value, the higher the wind speed and lower the relative humidity. Analysis of influencing factors <span class="hlt">reveals</span> that the <span class="hlt">air</span> pollution is mainly particulate matter produced by burning coal, vehicle emissions, volatile oils and gas, fast development of food services, emissions from the surrounding region, and natural dust clouds formed in arid areas to the northwest. Topography affects the distribution of meteorological conditions, in turn varying <span class="hlt">air</span> quality over the region from one location to another. Human activities also exercise impact on urban <span class="hlt">air</span> quality with dual functions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27097480','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27097480"><span>[Research on dust mite allergen gathered from filters of <span class="hlt">air</span>-conditioners].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhan, Xiao-dong; Wu, Hua; Hu, Hui-min; Li, Chao-pin</p> <p>2015-12-01</p> <p>To discuss the relation between the dust mite allergen (Der) in <span class="hlt">air</span>-conditioner filters and the asthma attack. The dust <span class="hlt">samples</span> were collected from the filters of <span class="hlt">air</span>-conditioners in dining rooms, shopping malls, hotels and households, respectively. The concentrations of Der f 1 and Der p1 were detected by ELISA, and the dust mite immune activities were determined by dot-ELISA. The concentrations of Der f 1 in the dining rooms, shopping malls, hotels and households were 1.52, 1.24, 1.31 µg/g and 1.46 µg/g respectively, and the concentrations of Der p 1 were 1.23, 1.12, 1.16 µg/ g and 1.18 µg, respectively. One hour after the running of <span class="hlt">air</span>-conditioners, the concentrations of Der f 1 and Der p 1 in the <span class="hlt">air</span> were higher than those before the running of <span class="hlt">air</span>-conditioners, and the differences were significant (P < 0.05). Additionally, the dot-ELISA results <span class="hlt">revealed</span> that the allergen extracted from the dust was capable of reacting with IgE from the sera of asthma mice allergic to dust mites. Der f 1 and Der p 1 appear abundantly in the filters of <span class="hlt">air</span>-conditioners in domestic houses in Wuhu City, and the allergens can induce asthma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24817348','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24817348"><span>Development and validation of a sensitive thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method for the determination of phosgene in <span class="hlt">air</span> <span class="hlt">samples</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Juillet, Y; Dubois, C; Bintein, F; Dissard, J; Bossée, A</p> <p>2014-08-01</p> <p>A new rapid, sensitive and reliable method was developed for the determination of phosgene in <span class="hlt">air</span> <span class="hlt">samples</span> using thermal desorption (TD) followed by gas chromatography-mass spectrometry (GC-MS). The method is based on a fast (10 min) active <span class="hlt">sampling</span> of only 1 L of <span class="hlt">air</span> onto a Tenax® GR tube doped with 0.5 mL of derivatizing mixture containing dimercaptotoluene and triethylamine in hexane solution. Validation of the TD-GC-MS method showed a low limit of detection (40 ppbv), acceptable repeatability, intermediate fidelity (relative standard deviation within 12 %) and excellent accuracy (>95%). Linearity was demonstrated for two concentration ranges (0.04 to 2.5 ppmv and 2.5 to 10 ppmv) owing to variation of derivatization recovery between low and high concentration levels. Due to its simple on-site implementation and its close similarity with recommended operating procedure (ROP) for chemical warfare agents vapour <span class="hlt">sampling</span>, the method is particularly useful in the process of verification of the Chemical Weapons Convention.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/380985-vapor-phase-particulate-associated-pesticides-pcb-concentrations-eastern-north-dakota-air-samples','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/380985-vapor-phase-particulate-associated-pesticides-pcb-concentrations-eastern-north-dakota-air-samples"><span>Vapor-phase and particulate-associated pesticides and PCB concentrations in eastern North Dakota <span class="hlt">air</span> <span class="hlt">samples</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hawthorne, S.B.; Miller, D.J.; Louie, P.K.K.</p> <p>1996-05-01</p> <p>Vapor-phase and suspended particulate (<50 {mu}m) <span class="hlt">samples</span> were collected on polyurethane foam (PUF) and quartz fiber filters in rural North Dakota to determine the <span class="hlt">air</span> concentrations of pesticides in an area where agriculture is a primary source of semivolatile pollutants. <span class="hlt">Samples</span> were collected at two sites from 1992 to 1994 that were at least 0.4 km from the nearest farmed fields and known application of pesticides, and analyzed for 22 different organochlorine, triazine, and acid herbicide pesticides. Fourteen pesticides were found above the detection limits (typically <1 pg/m{sup 3}). Concentrations of polychlorinated biphenyl (PCB) congeners were much lower (<50 pg/m{supmore » 3} in all cases) than many of the pesticides. These results demonstrate that pesticides are among the most prevalent chlorinated semivolatile pollutants present in rural North Dakota, that significant transport of pesticides occurs both in the vapor-phase and on suspended particulate matter, and that blown soil may be a significant mechanism for introducing pesticides into surface and ground waters. 32 refs., 2 figs., 4 tabs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=23129&Lab=NERL&keyword=guns&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=23129&Lab=NERL&keyword=guns&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>NHEXAS PHASE I ARIZONA STUDY--METALS IN <span class="hlt">AIR</span> ANALYTICAL RESULTS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The Metals in <span class="hlt">Air</span> data set contains analytical results for measurements of up to 11 metals in 369 <span class="hlt">air</span> <span class="hlt">samples</span> over 175 households. <span class="hlt">Samples</span> were taken by pumping standardized <span class="hlt">air</span> volumes through filters at indoor and outdoor sites around each household being <span class="hlt">sampled</span>. The primary...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15047764','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15047764"><span><span class="hlt">Air</span> volume measurement of 'Braeburn' apple fruit.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Drazeta, Lazar; Lang, Alexander; Hall, Alistair J; Volz, Richard K; Jameson, Paula E</p> <p>2004-05-01</p> <p>The radial disposition of <span class="hlt">air</span> in the flesh of fruit of Malus domestica Borkh., cv 'Braeburn' was investigated using a gravimetric technique based on Archimedes' principle. Intercellular <span class="hlt">air</span> volume was measured by weighing a small tissue <span class="hlt">sample</span> under water before and after vacuum infiltration to remove the <span class="hlt">air</span>. In a separate procedure, the volume of the same <span class="hlt">sample</span> was measured by recording the buoyant upthrust experienced by it when fully immersed in water. The method underestimates tissue <span class="hlt">air</span> volume due to a slight invasion of the intercellular <span class="hlt">air</span> spaces around the edges of the <span class="hlt">sample</span> when it is immersed in water. To correct for this error, an adjustment factor was made based upon an analysis of a series of measurements of <span class="hlt">air</span> volume in <span class="hlt">samples</span> of different dimensions. In 'Braeburn' there is a gradient of declining <span class="hlt">air</span> content from just beneath the skin to the centre of the fruit with a sharp discontinuity at the core line. Cell shape and cell packing were observed in the surface layers of freshly excised and stained flesh <span class="hlt">samples</span> using a dissecting microscope coupled to a video camera and a PC running proprietary software. Tissue organization changed with distance below the skin. It is speculated that reduced internal gas movement, due to the tightly packed tissue of 'Braeburn' and to the potential diffusion barrier at the core line between the cortex and the pith, may increase susceptibility of the flesh to disorders associated with tissue browning and breakdown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23896655','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23896655"><span>Development of a unique multi-contaminant <span class="hlt">air</span> <span class="hlt">sampling</span> device for a childhood asthma cohort in an agricultural environment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Armstrong, Jenna L; Fitzpatrick, Cole F; Loftus, Christine T; Yost, Michael G; Tchong-French, Maria; Karr, Catherine J</p> <p>2013-09-01</p> <p>This research describes the design, deployment, performance, and acceptability of a novel outdoor active <span class="hlt">air</span> sampler to provide simultaneous measurements of multiple contaminants at timed intervals for the Aggravating Factors of Asthma in Rural Environment (AFARE) study-a longitudinal cohort of 50 children in Yakima Valley, Washington. The sampler was constructed of multiple <span class="hlt">sampling</span> media connected to individual critical orifices and a rotary vane vacuum pump. It was connected to a timed control valve system to collect 24 hours <span class="hlt">samples</span> every six days over 18 months. We describe a spatially representative approach with both quantitative and qualitative location criteria to deploy a network of 14 devices at participant residences in a rural region (20 × 60 km). Overall the sampler performed well, as the concurrent mean <span class="hlt">sample</span> flow rates were within or above the ranges of recommended <span class="hlt">sampling</span> rates for each exposure metric of interest. Acceptability was high among the study population of Hispanic farmworker participant households. The sampler design may prove useful for future urban and rural community-based studies with aims at collecting multiple contaminant data during specific time periods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1127148','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1127148"><span>Uncertainties in <span class="hlt">Air</span> Exchange using Continuous-Injection, Long-Term <span class="hlt">Sampling</span> Tracer-Gas Methods</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Sherman, Max H.; Walker, Iain S.; Lunden, Melissa M.</p> <p>2013-12-01</p> <p>The PerFluorocarbon Tracer (PFT) method is a low-cost approach commonly used for measuring <span class="hlt">air</span> exchange in buildings using tracer gases. It is a specific application of the more general Continuous-Injection, Long-Term <span class="hlt">Sampling</span> (CILTS) method. The technique is widely used but there has been little work on understanding the uncertainties (both precision and bias) associated with its use, particularly given that it is typically deployed by untrained or lightly trained people to minimize experimental costs. In this article we will conduct a first-principles error analysis to estimate the uncertainties and then compare that analysis to CILTS measurements that were over-<span class="hlt">sampled</span>, throughmore » the use of multiple tracers and emitter and sampler distribution patterns, in three houses. We find that the CILTS method can have an overall uncertainty of 10-15percent in ideal circumstances, but that even in highly controlled field experiments done by trained experimenters expected uncertainties are about 20percent. In addition, there are many field conditions (such as open windows) where CILTS is not likely to provide any quantitative data. Even avoiding the worst situations of assumption violations CILTS should be considered as having a something like a ?factor of two? uncertainty for the broad field trials that it is typically used in. We provide guidance on how to deploy CILTS and design the experiment to minimize uncertainties.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol8/pdf/CFR-2010-title40-vol8-sec61-34.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol8/pdf/CFR-2010-title40-vol8-sec61-34.pdf"><span>40 CFR 61.34 - <span class="hlt">Air</span> <span class="hlt">sampling</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... filters, or for replacement of equipment needing major repair. (c) Filters shall be analyzed and concentrations calculated within 30 days after filters are collected. Records of concentrations at all <span class="hlt">sampling</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol9/pdf/CFR-2014-title40-vol9-sec61-34.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol9/pdf/CFR-2014-title40-vol9-sec61-34.pdf"><span>40 CFR 61.34 - <span class="hlt">Air</span> <span class="hlt">sampling</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... filters, or for replacement of equipment needing major repair. (c) Filters shall be analyzed and concentrations calculated within 30 days after filters are collected. Records of concentrations at all <span class="hlt">sampling</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19771380','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19771380"><span><span class="hlt">Air</span>-borne heavy metal contamination to dietary vegetables: a case study from India.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pandey, J; Pandey, Richa; Shubhashish, K</p> <p>2009-12-01</p> <p>Contamination of edible parts of three dietary vegetables, Spinach (Spinacia oleracea L.), Radish (Raphanus sativus L.), and Tomato (Lycopersicon esculentum Mill.) by <span class="hlt">air</span>-borne cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb) was determined using pot culture experiments at three sites in the city of Varanasi, India. The data <span class="hlt">revealed</span> that although Cr and Cu in vegetables remained below their safe limits, about 68% of the total <span class="hlt">samples</span> contained Cd, Ni, and Pb above their respective safe limits of 1.5, 1.5, and 2.5 μg g(-1). Site wise synchrony and <span class="hlt">air</span> accumulation factor (AAF) indicated that atmospheric deposition was the main contributor of metal contamination to vegetables. The study suggests that if the present trends of atmospheric deposition are continued, <span class="hlt">air</span>-borne heavy metals will contaminate the agricultural produce with long-term health implications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1335784','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1335784"><span>Magnesium, Iron and Aluminum in LLNL <span class="hlt">Air</span> Particulate and Rain <span class="hlt">Samples</span> with Reference to Magnesium in Industrial Storm Water</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Esser, Bradley K.; Bibby, Richard K.; Fish, Craig</p> <p></p> <p>Storm water runoff from the Lawrence Livermore National Laboratory’s (LLNL’s) main site and Site 300 periodically exceeds the Discharge Permit Numeric Action Level (NAL) for Magnesium (Mg) under the Industrial General Permit (IGP) Order No. 2014-0057-DWQ. Of particular interest is the source of magnesium in storm water runoff from the site. This special study compares new metals data from <span class="hlt">air</span> particulate and precipitation <span class="hlt">samples</span> from the LLNL main site and Site 300 to previous metals data for storm water from the main site and Site 300 and alluvial sediment from the main site to investigate the potential source of elevatedmore » Mg in storm water runoff. Data for three metals (Mg, Iron {Fe}, and Aluminum {Al}) were available from all media; data for additional metals, such as Europium (Eu), were available from rain, <span class="hlt">air</span> particulates, and alluvial sediment. To attribute source, this study compared metals concentration data (for Mg, Al, and Fe) in storm water and rain; metal-metal correlations (Mg with Fe, Mg with Al, Al with Fe, Mg with Eu, Eu with Fe, and Eu with Al) in storm water, rain, <span class="hlt">air</span> particulates, and sediments; and metal-metal ratios ((Mg/Fe, Mg/Al, Al/Fe, Mg/Eu, Eu/Fe, and Eu/Al) in storm water, rain, <span class="hlt">air</span> particulates and sediments. The results presented in this study are consistent with a simple conceptual model where the source of Mg in storm water runoff is <span class="hlt">air</span> particulate matter that has dry-deposited on impervious surfaces and subsequently entrained in runoff during precipitation events. Such a conceptual model is consistent with 1) higher concentrations of metals in storm water runoff than in precipitation, 2) the strong correlation of Mg with Aluminum (Al) and Iron (Fe) in both storm water and <span class="hlt">air</span> particulates, and 3) the similarity in metal mass ratios between storm water and <span class="hlt">air</span> particulates in contrast to the dissimilarity of metal mass ratios between storm water and precipitation or alluvial sediment. The strong correlation of Mg with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26642083','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26642083"><span>Gaseous and Freely-Dissolved PCBs in the Lower Great Lakes Based on Passive <span class="hlt">Sampling</span>: Spatial Trends and <span class="hlt">Air</span>-Water Exchange.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Ying; Wang, Siyao; McDonough, Carrie A; Khairy, Mohammed; Muir, Derek C G; Helm, Paul A; Lohmann, Rainer</p> <p>2016-05-17</p> <p>Polyethylene passive <span class="hlt">sampling</span> was performed to quantify gaseous and freely dissolved polychlorinated biphenyls (PCBs) in the <span class="hlt">air</span> and water of Lakes Erie and Ontario during 2011-2012. In view of differing physical characteristics and the impacts of historical contamination by PCBs within these lakes, spatial variation of PCB concentrations and <span class="hlt">air</span>-water exchange across these lakes may be expected. Both lakes displayed statistically similar aqueous and atmospheric PCB concentrations. Total aqueous concentrations of 29 PCBs ranged from 1.5 pg L(-1) in the open lake of Lake Erie (site E02) in 2011 spring to 105 pg L(-1) in Niagara (site On05) in 2012 summer, while total atmospheric concentrations were 7.7-634 pg m(-3) across both lakes. A west-to-east gradient was observed for aqueous PCBs in Lake Erie. River discharge and localized influences (e.g., sediment resuspension and regional alongshore transport) likely dominated spatial trends of aqueous PCBs in both lakes. <span class="hlt">Air</span>-water exchange fluxes of Σ7PCBs ranged from -2.4 (±1.9) ng m(-2) day(-1) (deposition) in Sheffield (site E03) to 9.0 (±3.1) ng m(-2) day(-1) (volatilization) in Niagara (site On05). Net volatilization of PCBs was the primary trend across most sites and periods. Almost half of variation in <span class="hlt">air</span>-water exchange fluxes was attributed to the difference in aqueous concentrations of PCBs. Uncertainty analysis in fugacity ratios and mass fluxes in <span class="hlt">air</span>-water exchange of PCBs indicated that PCBs have reached or approached equilibrium only at the eastern Lake Erie and along the Canadian shore of Lake Ontario sites, where <span class="hlt">air</span>-water exchange fluxes dominated atmospheric concentrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1237084','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1237084"><span>Direct impact aerosol <span class="hlt">sampling</span> by electrostatic precipitation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Braden, Jason D.; Harter, Andrew G.; Stinson, Brad J.; Sullivan, Nicholas M.</p> <p>2016-02-02</p> <p>The present disclosure provides apparatuses for collecting aerosol <span class="hlt">samples</span> by ionizing an <span class="hlt">air</span> <span class="hlt">sample</span> at different degrees. An <span class="hlt">air</span> flow is generated through a cavity in which at least one corona wire is disposed and electrically charged to form a corona therearound. At least one grounded <span class="hlt">sample</span> collection plate is provided downstream of the at least one corona wire so that aerosol ions generated within the corona are deposited on the at least one grounded <span class="hlt">sample</span> collection plate. A plurality of aerosol <span class="hlt">samples</span> ionized to different degrees can be generated. The at least one corona wire may be perpendicular to the direction of the flow, or may be parallel to the direction of the flow. The apparatus can include a serial connection of a plurality of stages such that each stage is capable of generating at least one aerosol <span class="hlt">sample</span>, and the <span class="hlt">air</span> flow passes through the plurality of stages serially.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28363251','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28363251"><span>Assessment of <span class="hlt">air</span> <span class="hlt">sampling</span> methods and size distribution of virus-laden aerosols in outbreaks in swine and poultry farms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alonso, Carmen; Raynor, Peter C; Goyal, Sagar; Olson, Bernard A; Alba, Anna; Davies, Peter R; Torremorell, Montserrat</p> <p>2017-05-01</p> <p>Swine and poultry viruses, such as porcine reproductive and respiratory syndrome virus (PRRSV), porcine epidemic diarrhea virus (PEDV), and highly pathogenic avian influenza virus (HPAIV), are economically important pathogens that can spread via aerosols. The reliability of methods for quantifying particle-associated viruses as well as the size distribution of aerosolized particles bearing these viruses under field conditions are not well documented. We compared the performance of 2 size-differentiating <span class="hlt">air</span> samplers in disease outbreaks that occurred in swine and poultry facilities. Both <span class="hlt">air</span> samplers allowed quantification of particles by size, and measured concentrations of PRRSV, PEDV, and HPAIV stratified by particle size both within and outside swine and poultry facilities. All 3 viruses were detectable in association with aerosolized particles. Proportions of positive <span class="hlt">sampling</span> events were 69% for PEDV, 61% for HPAIV, and 8% for PRRSV. The highest virus concentrations were found with PEDV, followed by HPAIV and PRRSV. Both <span class="hlt">air</span> collectors performed equally for the detection of total virus concentration. For all 3 viruses, higher numbers of RNA copies were associated with larger particles; however, a bimodal distribution of particles was observed in the case of PEDV and HPAIV.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23521112','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23521112"><span>Bacterial population dynamics during the ensiling of Medicago sativa (alfalfa) and subsequent exposure to <span class="hlt">air</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McGarvey, J A; Franco, R B; Palumbo, J D; Hnasko, R; Stanker, L; Mitloehner, F M</p> <p>2013-06-01</p> <p>To describe, at high resolution, the bacterial population dynamics and chemical transformations during the ensiling of alfalfa and subsequent exposure to <span class="hlt">air</span>. <span class="hlt">Samples</span> of alfalfa, ensiled alfalfa and silage exposed to <span class="hlt">air</span> were collected and their bacterial population structures compared using 16S rRNA gene libraries containing approximately 1900 sequences each. Cultural and chemical analyses were also performed to complement the 16S gene sequence data. Sequence analysis <span class="hlt">revealed</span> significant differences (P < 0·05) in the bacterial populations at each time point. The alfalfa-derived library contained mostly sequences associated with the Gammaproteobacteria (including the genera: Enterobacter, Erwinia and Pantoea); the ensiled material contained mostly sequences associated with the lactic acid bacteria (LAB) (including the genera: Lactobacillus, Pediococcus and Lactococcus). Exposure to <span class="hlt">air</span> resulted in even greater percentages of LAB, especially among the genus Lactobacillus, and a significant drop in bacterial diversity. In-depth 16S rRNA gene sequence analysis <span class="hlt">revealed</span> significant bacterial population structure changes during ensiling and again during exposure to <span class="hlt">air</span>. This in-depth description of the bacterial population dynamics that occurred during ensiling and simulated feed out expands our knowledge of these processes. © 2013 The Society for Applied Microbiology No claim to US Government works.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title32-vol6/pdf/CFR-2011-title32-vol6-sec865-126.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title32-vol6/pdf/CFR-2011-title32-vol6-sec865-126.pdf"><span>32 CFR 865.126 - <span class="hlt">Sample</span> report format.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 32 National Defense 6 2011-07-01 2011-07-01 false <span class="hlt">Sample</span> report format. 865.126 Section 865.126 National Defense Department of Defense (Continued) DEPARTMENT OF THE <span class="hlt">AIR</span> FORCE ORGANIZATION AND MISSION-GENERAL PERSONNEL REVIEW BOARDS <span class="hlt">Air</span> Force Discharge Review Board § 865.126 <span class="hlt">Sample</span> report format. Summary...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title32-vol6/pdf/CFR-2013-title32-vol6-sec865-126.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title32-vol6/pdf/CFR-2013-title32-vol6-sec865-126.pdf"><span>32 CFR 865.126 - <span class="hlt">Sample</span> report format.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... 32 National Defense 6 2013-07-01 2013-07-01 false <span class="hlt">Sample</span> report format. 865.126 Section 865.126 National Defense Department of Defense (Continued) DEPARTMENT OF THE <span class="hlt">AIR</span> FORCE ORGANIZATION AND MISSION-GENERAL PERSONNEL REVIEW BOARDS <span class="hlt">Air</span> Force Discharge Review Board § 865.126 <span class="hlt">Sample</span> report format. Summary...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22102896','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22102896"><span>Use of respondent driven <span class="hlt">sampling</span> (RDS) generates a very diverse <span class="hlt">sample</span> of men who have sex with men (MSM) in Buenos <span class="hlt">Aires</span>, Argentina.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carballo-Diéguez, Alex; Balan, Ivan; Marone, Rubén; Pando, María A; Dolezal, Curtis; Barreda, Victoria; Leu, Cheng-Shiun; Avila, María Mercedes</p> <p>2011-01-01</p> <p>Prior research focusing on men who have sex with men (MSM) conducted in Buenos <span class="hlt">Aires</span>, Argentina, used convenience <span class="hlt">samples</span> that included mainly gay identified men. To increase MSM <span class="hlt">sample</span> representativeness, we used Respondent Driven <span class="hlt">Sampling</span> (RDS) for the first time in Argentina. Using RDS, under certain specified conditions, the observed estimates for the percentage of the population with a specific trait are asymptotically unbiased. We describe, the diversity of the recruited <span class="hlt">sample</span>, from the point of view of sexual orientation, and contrast the different subgroups in terms of their HIV sexual risk behavior. 500 MSM were recruited using RDS. Behavioral data were collected through face-to-face interviews and Web-based CASI. In contrast with prior studies, RDS generated a very diverse <span class="hlt">sample</span> of MSM from a sexual identity perspective. Only 24.5% of participants identified as gay; 36.2% identified as bisexual, 21.9% as heterosexual, and 17.4% were grouped as "other." Gay and non-gay identified MSM differed significantly in their sexual behavior, the former having higher numbers of partners, more frequent sexual contacts and less frequency of condom use. One third of the men (gay, 3%; bisexual, 34%, heterosexual, 51%; other, 49%) reported having had sex with men, women and transvestites in the two months prior to the interview. This population requires further study and, potentially, HIV prevention strategies tailored to such diversity of partnerships. Our results highlight the potential effectiveness of using RDS to reach non-gay identified MSM. They also present lessons learned in the implementation of RDS to recruit MSM concerning both the importance and limitations of formative work, the need to tailor incentives to circumstances of the less affluent potential participants, the need to prevent masking, and the challenge of assessing network size.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3213136','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3213136"><span>Use of Respondent Driven <span class="hlt">Sampling</span> (RDS) Generates a Very Diverse <span class="hlt">Sample</span> of Men Who Have Sex with Men (MSM) in Buenos <span class="hlt">Aires</span>, Argentina</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Carballo-Diéguez, Alex; Balan, Ivan; Marone, Rubén; Pando, María A.; Dolezal, Curtis; Barreda, Victoria; Leu, Cheng-Shiun; Ávila, María Mercedes</p> <p>2011-01-01</p> <p>Background Prior research focusing on men who have sex with men (MSM) conducted in Buenos <span class="hlt">Aires</span>, Argentina, used convenience <span class="hlt">samples</span> that included mainly gay identified men. To increase MSM <span class="hlt">sample</span> representativeness, we used Respondent Driven <span class="hlt">Sampling</span> (RDS) for the first time in Argentina. Using RDS, under certain specified conditions, the observed estimates for the percentage of the population with a specific trait are asymptotically unbiased. We describe, the diversity of the recruited <span class="hlt">sample</span>, from the point of view of sexual orientation, and contrast the different subgroups in terms of their HIV sexual risk behavior. Methodology 500 MSM were recruited using RDS. Behavioral data were collected through face-to-face interviews and Web-based CASI. Conclusion In contrast with prior studies, RDS generated a very diverse <span class="hlt">sample</span> of MSM from a sexual identity perspective. Only 24.5% of participants identified as gay; 36.2% identified as bisexual, 21.9% as heterosexual, and 17.4% were grouped as “other.” Gay and non-gay identified MSM differed significantly in their sexual behavior, the former having higher numbers of partners, more frequent sexual contacts and less frequency of condom use. One third of the men (gay, 3%; bisexual, 34%, heterosexual, 51%; other, 49%) reported having had sex with men, women and transvestites in the two months prior to the interview. This population requires further study and, potentially, HIV prevention strategies tailored to such diversity of partnerships. Our results highlight the potential effectiveness of using RDS to reach non-gay identified MSM. They also present lessons learned in the implementation of RDS to recruit MSM concerning both the importance and limitations of formative work, the need to tailor incentives to circumstances of the less affluent potential participants, the need to prevent masking, and the challenge of assessing network size. PMID:22102896</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4659959','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4659959"><span>Changes over Time in Intracranial <span class="hlt">Air</span> in Patients with Cerebral <span class="hlt">Air</span> Embolism: Radiological Study in Two Cases</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kaichi, Yoko; Kakeda, Shingo; Korogi, Yukunori; Nezu, Tomohisa; Aoki, Shiro; Matsumoto, Masayasu; Iida, Makoto; Awai, Kazuo</p> <p>2015-01-01</p> <p>Cerebral <span class="hlt">air</span> embolism can be easily identified on computed tomography (CT) scans. However, changes in the distribution and amount of intracranial <span class="hlt">air</span> are not well known. We report two patients with cerebral <span class="hlt">air</span> embolism and present imaging findings on the serial changes in the intracranial <span class="hlt">air</span>. We thought that the embolic source was venous in one patient because CT showed <span class="hlt">air</span> inflow in cortical veins in the bilateral frontal areas, reflecting <span class="hlt">air</span> buoyancy. In the other patient, CT showed <span class="hlt">air</span> inflow into not only the cortical veins but also the bilateral cerebral hemispheres and we thought this to be a paradoxical cerebral <span class="hlt">air</span> embolism. We found that intracranial <span class="hlt">air</span> can be promptly absorbed and while cerebral infarcts due to <span class="hlt">air</span> are clearly visualized on diffusion-weighted images (DWI), the <span class="hlt">air</span> may rapidly disappear from images. In patients with suspected cerebral <span class="hlt">air</span> embolism whose CT findings show no intracranial <span class="hlt">air</span>, DWI should be performed because it may <span class="hlt">reveal</span> cerebral infarction due to cerebral <span class="hlt">air</span> embolism. PMID:26640730</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28726722','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28726722"><span>Comparison of the Results of Studies of <span class="hlt">Air</span> Pollution Fungi Using the SAS Super 100, MAS 100, and <span class="hlt">Air</span> IDEAL.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Łukaszuk, Cecylia; Krajewska-Kułak, Elżbieta; Guzowski, Andrzej; Kułak, Wojciech; Kraszyńska, Bogumiła</p> <p>2017-07-20</p> <p>Although several <span class="hlt">air</span> <span class="hlt">sampling</span> devices for identifying and enumerating airborne microorganisms are commercially available, each poses some limitations. The aim of this study was to evaluate <span class="hlt">air</span> pollution fungi using three such samplers: SAS Super 100, Microbiological <span class="hlt">Air</span> Sampler (MAS) 100, and <span class="hlt">Air</span> IDEAL. Mycological <span class="hlt">air</span> was taken from the cellars of a 17th-century church in Siemiatycze, Poland, and the nearby outdoor environment. With samplers placed 1.5 m above the floor, microbial flora in <span class="hlt">air</span> <span class="hlt">samples</span> collected inside and outside the cellar were detected. The number of colony-forming units (CFU) of fungi obtained with the three samplers from the cellars and outdoor environment differed; the most CFU were obtained with the <span class="hlt">Air</span> IDEAL and the least with the SAS Super 100. Significant differences emerged in CFUs collected from <span class="hlt">air</span> <span class="hlt">samples</span> with the MAS 100 and SAS Super 100, on the one hand, and the SAS Super 100 and <span class="hlt">Air</span> IDEAL, on the other. Otherwise, results among the samplers were different. More Cladosporium species were collected with the MAS 100 sampler, whereas more Fusarium and Aspergillus species were collected with the <span class="hlt">Air</span> IDEAL sampler. Significant differences among CFU/m³ values among the tested sites depended on the sampler used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/4238250','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/4238250"><span>ANNULAR IMPACTOR <span class="hlt">SAMPLING</span> DEVICE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Tait, G.W.C.</p> <p>1959-03-31</p> <p>A high-rate <span class="hlt">air</span> sampler capable of <span class="hlt">sampling</span> alphaemitting particles as small as 0.5 microns is described. The device is a cylindrical shaped cup that fits in front of a suction tube and which has sticky grease coating along its base. Suction forces contaminated <span class="hlt">air</span> against the periodically monitored particle absorbing grease.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24425189','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24425189"><span>Transgenic zebrafish <span class="hlt">reveal</span> tissue-specific differences in estrogen signaling in response to environmental water <span class="hlt">samples</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gorelick, Daniel A; Iwanowicz, Luke R; Hung, Alice L; Blazer, Vicki S; Halpern, Marnie E</p> <p>2014-04-01</p> <p>Environmental endocrine disruptors (EEDs) are exogenous chemicals that mimic endogenous hormones such as estrogens. Previous studies using a zebrafish transgenic reporter demonstrated that the EEDs bisphenol A and genistein preferentially activate estrogen receptors (ERs) in the larval heart compared with the liver. However, it was not known whether the transgenic zebrafish reporter was sensitive enough to detect estrogens from environmental <span class="hlt">samples</span>, whether environmental estrogens would exhibit tissue-specific effects similar to those of BPA and genistein, or why some compounds preferentially target receptors in the heart. We tested surface water <span class="hlt">samples</span> using a transgenic zebrafish reporter with tandem estrogen response elements driving green fluorescent protein expression (5xERE:GFP). Reporter activation was colocalized with tissue-specific expression of ER genes by RNA in situ hybridization. We observed selective patterns of ER activation in transgenic fish exposed to river water <span class="hlt">samples</span> from the Mid-Atlantic United States, with several <span class="hlt">samples</span> preferentially activating receptors in embryonic and larval heart valves. We discovered that tissue specificity in ER activation was due to differences in the expression of ER subtypes. ERα was expressed in developing heart valves but not in the liver, whereas ERβ2 had the opposite profile. Accordingly, subtype-specific ER agonists activated the reporter in either the heart valves or the liver. The use of 5xERE:GFP transgenic zebrafish <span class="hlt">revealed</span> an unexpected tissue-specific difference in the response to environmentally relevant estrogenic compounds. Exposure to estrogenic EEDs in utero was associated with adverse health effects, with the potentially unanticipated consequence of targeting developing heart valves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70048326','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70048326"><span>Transgenic zebrafish <span class="hlt">reveal</span> tissue-specific differences in estrogen signaling in response to environmental water <span class="hlt">samples</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gorelick, Daniel A.; Iwanowicz, Luke R.; Hung, Alice L.; Blazer, Vicki; Halpern, Marnie E.</p> <p>2014-01-01</p> <p>Background: Environmental endocrine disruptors (EED) are exogenous chemicals that mimic endogenous hormones, such as estrogens. Previous studies using a zebrafish transgenic reporter demonstrated that the EEDs bisphenol A and genistein preferentially activate estrogen receptors (ER) in the larval heart compared to the liver. However, it was not known whether the transgenic zebrafish reporter was sensitive enough to detect estrogens from environmental <span class="hlt">samples</span>, whether environmental estrogens would exhibit similar tissue-specific effects as BPA and genistein or why some compounds preferentially target receptors in the heart. Methods: We tested surface water <span class="hlt">samples</span> using a transgenic zebrafish reporter with tandem estrogen response elements driving green fluorescent protein expression (5xERE:GFP). Reporter activation was colocalized with tissue-specific expression of estrogen receptor genes by RNA in situ hybridization. Results: Selective patterns of ER activation were observed in transgenic fish exposed to river water <span class="hlt">samples</span> from the Mid-Atlantic United States, with several <span class="hlt">samples</span> preferentially activating receptors in embryonic and larval heart valves. We discovered that tissue-specificity in ER activation is due to differences in the expression of estrogen receptor subtypes. ERα is expressed in developing heart valves but not in the liver, whereas ERβ2 has the opposite profile. Accordingly, subtype-specific ER agonists activate the reporter in either the heart valves or the liver. Conclusion: The use of 5xERE:GFP transgenic zebrafish has <span class="hlt">revealed</span> an unexpected tissue-specific difference in the response to environmentally relevant estrogenic compounds. Exposure to estrogenic EEDs in utero is associated with adverse health effects, with the potentially unanticipated consequence of targeting developing heart valves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4726533','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4726533"><span>Comparative Study of the Effect of <span class="hlt">Sample</span> Pretreatment and Extraction on the Determination of Flavonoids from Lemon (Citrus limon)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ledesma-Escobar, Carlos A.; Priego-Capote, Feliciano; Luque de Castro, María D.</p> <p>2016-01-01</p> <p>Background Flavonoids have shown to exert multiple beneficial effects on human health, being also appreciated by both food and pharmaceutical industries. Citrus fruits are a key source of flavonoids, thus promoting studies to obtain them. Characteristics of these studies are the discrepancies among <span class="hlt">sample</span> pretreatments and among extraction methods, and also the scant number of comparative studies developed so far. Objective Evaluate the effect of both the <span class="hlt">sample</span> pretreatment and the extraction method on the profile of flavonoids isolated from lemon. Results Extracts from fresh, lyophilized and <span class="hlt">air</span>-dried <span class="hlt">samples</span> obtained by shaking extraction (SE), ultrasound-assisted extraction (USAE), microwave-assisted extraction (MAE) and superheated liquid extraction (SHLE) were analyzed by LC–QTOF MS/MS, and 32 flavonoids were tentatively identified using MS/MS information. ANOVA applied to the data from fresh and dehydrated <span class="hlt">samples</span> and from extraction by the different methods <span class="hlt">revealed</span> that 26 and 32 flavonoids, respectively, were significant (p≤0.01). The pairwise comparison (Tukey HSD; p≤0.01) showed that lyophilized <span class="hlt">samples</span> are more different from fresh <span class="hlt">samples</span> than from <span class="hlt">air</span>-dried <span class="hlt">samples</span>; also, principal component analysis (PCA) showed a clear discrimination among <span class="hlt">sample</span> pretreatment strategies and suggested that such differences are mainly created by the abundance of major flavonoids. On the other hand, pairwise comparison of extraction methods <span class="hlt">revealed</span> that USAE and MAE provided quite similar extracts, being SHLE extracts different from the other two. In this case, PCA showed a clear discrimination among extraction methods, and their position in the scores plot suggests a lower abundance of flavonoids in the extracts from SHLE. In the two PCA the loadings plots <span class="hlt">revealed</span> a trend to forming groups according to flavonoid aglycones. Conclusions The present study shows clear discrimination caused by both <span class="hlt">sample</span> pretreatments and extraction methods. Under the studied</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4412456','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4412456"><span>Microbial <span class="hlt">Air</span> Quality and Bacterial Surface Contamination in Ambulances During Patient Services</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Luksamijarulkul, Pipat; Pipitsangjan, Sirikun</p> <p>2015-01-01</p> <p>Objectives We sought to assess microbial <span class="hlt">air</span> quality and bacterial surface contamination on medical instruments and the surrounding areas among 30 ambulance runs during service. Methods We performed a cross-sectional study of 106 <span class="hlt">air</span> <span class="hlt">samples</span> collected from 30 ambulances before patient services and 212 <span class="hlt">air</span> <span class="hlt">samples</span> collected during patient services to assess the bacterial and fungal counts at the two time points. Additionally, 226 surface swab <span class="hlt">samples</span> were collected from medical instrument surfaces and the surrounding areas before and after ambulance runs. Groups or genus of isolated bacteria and fungi were preliminarily identified by Gram’s stain and lactophenol cotton blue. Data were analyzed using descriptive statistics, t-test, and Pearson’s correlation coefficient with a p-value of less than 0.050 considered significant. Results The mean and standard deviation of bacterial and fungal counts at the start of ambulance runs were 318±485cfu/m3 and 522±581cfu/m3, respectively. Bacterial counts during patient services were 468±607cfu/m3 and fungal counts were 656±612cfu/m3. Mean bacterial and fungal counts during patient services were significantly higher than those at the start of ambulance runs, p=0.005 and p=0.030, respectively. For surface contamination, the overall bacterial counts before and after patient services were 0.8±0.7cfu/cm2 and 1.3±1.1cfu/cm2, respectively (p<0.001). The predominant isolated bacteria and fungi were Staphylococcus spp. and Aspergillus spp., respectively. Additionally, there was a significantly positive correlation between bacterial (r=0.3, p<0.010) and fungal counts (r=0.2, p=0.020) in <span class="hlt">air</span> <span class="hlt">samples</span> and bacterial counts on medical instruments and allocated areas. Conclusions This study <span class="hlt">revealed</span> high microbial contamination (bacterial and fungal) in ambulance <span class="hlt">air</span> during services and higher bacterial contamination on medical instrument surfaces and allocated areas after ambulance services compared to the start of ambulance runs</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25960835','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25960835"><span>Microbial <span class="hlt">air</span> quality and bacterial surface contamination in ambulances during patient services.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luksamijarulkul, Pipat; Pipitsangjan, Sirikun</p> <p>2015-03-01</p> <p>We sought to assess microbial <span class="hlt">air</span> quality and bacterial surface contamination on medical instruments and the surrounding areas among 30 ambulance runs during service. We performed a cross-sectional study of 106 <span class="hlt">air</span> <span class="hlt">samples</span> collected from 30 ambulances before patient services and 212 <span class="hlt">air</span> <span class="hlt">samples</span> collected during patient services to assess the bacterial and fungal counts at the two time points. Additionally, 226 surface swab <span class="hlt">samples</span> were collected from medical instrument surfaces and the surrounding areas before and after ambulance runs. Groups or genus of isolated bacteria and fungi were preliminarily identified by Gram's stain and lactophenol cotton blue. Data were analyzed using descriptive statistics, t-test, and Pearson's correlation coefficient with a p-value of less than 0.050 considered significant. The mean and standard deviation of bacterial and fungal counts at the start of ambulance runs were 318±485cfu/m(3) and 522±581cfu/m(3), respectively. Bacterial counts during patient services were 468±607cfu/m(3) and fungal counts were 656±612cfu/m(3). Mean bacterial and fungal counts during patient services were significantly higher than those at the start of ambulance runs, p=0.005 and p=0.030, respectively. For surface contamination, the overall bacterial counts before and after patient services were 0.8±0.7cfu/cm(2) and 1.3±1.1cfu/cm(2), respectively (p<0.001). The predominant isolated bacteria and fungi were Staphylococcus spp. and Aspergillus spp., respectively. Additionally, there was a significantly positive correlation between bacterial (r=0.3, p<0.010) and fungal counts (r=0.2, p=0.020) in <span class="hlt">air</span> <span class="hlt">samples</span> and bacterial counts on medical instruments and allocated areas. This study <span class="hlt">revealed</span> high microbial contamination (bacterial and fungal) in ambulance <span class="hlt">air</span> during services and higher bacterial contamination on medical instrument surfaces and allocated areas after ambulance services compared to the start of ambulance runs. Additionally, bacterial and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1394323','SCIGOV-DOEDE'); return false;" href="https://www.osti.gov/servlets/purl/1394323"><span>Measurements of Atmospheric Methane and 13C/12C of Atmospheric Methane from Flask <span class="hlt">Air</span> <span class="hlt">Samples</span> (1999)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/dataexplorer">DOE Data Explorer</a></p> <p>Quay, Paul [School of Oceanography, University of Washington; Stutsman, Johnny [School of Oceanography, University of Washington</p> <p>1999-01-01</p> <p>This database offers precise measurements of atmospheric methane and 13C/12C in atmospheric methane from flask <span class="hlt">air</span> <span class="hlt">samples</span> collected at eight sites worldwide and aboard NOAA cruises in the Pacific Ocean. The eight sites include Olympic Peninsula, Washington; Cape Grim, Tasmania; Fraserdale, Ontario; Marshall Islands; Baring Head, New Zealand; Mauna Loa, Hawaii; Point Barrow, Alaska; and American Samoa. The measurements span the period 1988 to mid-1996. These data are useful for global methane budget analyses and for determining the atmospheric isotopic composition of methane. All isotopic measurements have been corrected for standard drift.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25658553','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25658553"><span><span class="hlt">Revealing</span> hidden clonal complexity in Mycobacterium tuberculosis infection by qualitative and quantitative improvement of <span class="hlt">sampling</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pérez-Lago, L; Palacios, J J; Herranz, M; Ruiz Serrano, M J; Bouza, E; García-de-Viedma, D</p> <p>2015-02-01</p> <p>The analysis of microevolution events, its functional relevance and impact on molecular epidemiology strategies, constitutes one of the most challenging aspects of the study of clonal complexity in infection by Mycobacterium tuberculosis. In this study, we retrospectively evaluated whether two improved <span class="hlt">sampling</span> schemes could provide access to the clonal complexity that is undetected by the current standards (analysis of one isolate from one sputum). We evaluated in 48 patients the analysis by mycobacterial interspersed repetitive unit-variable number tandem repeat of M. tuberculosis isolates cultured from bronchial aspirate (BAS) or bronchoalveolar lavage (BAL) and, in another 16 cases, the analysis of a higher number of isolates from independent sputum <span class="hlt">samples</span>. Analysis of the isolates from BAS/BAL specimens <span class="hlt">revealed</span> clonal complexity in a very high proportion of cases (5/48); in most of these cases, complexity was not detected when the isolates from sputum <span class="hlt">samples</span> were analysed. Systematic analysis of isolates from multiple sputum <span class="hlt">samples</span> also improved the detection of clonal complexity. We found coexisting clonal variants in two of 16 cases that would have gone undetected in the analysis of the isolate from a single sputum specimen. Our results suggest that analysis of isolates from BAS/BAL specimens is highly efficient for recording the true clonal composition of M. tuberculosis in the lungs. When these <span class="hlt">samples</span> are not available, we recommend increasing the number of isolates from independent sputum specimens, because they might not harbour the same pool of bacteria. Our data suggest that the degree of clonal complexity in tuberculosis has been underestimated because of the deficiencies inherent in a simplified procedure. Copyright © 2014 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1065-245.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1065-245.pdf"><span>40 CFR 1065.245 - <span class="hlt">Sample</span> flow meter for batch <span class="hlt">sampling</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.245... difference between a diluted exhaust <span class="hlt">sample</span> flow meter and a dilution <span class="hlt">air</span> meter to calculate raw exhaust flow...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol33/pdf/CFR-2014-title40-vol33-sec1065-245.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol33/pdf/CFR-2014-title40-vol33-sec1065-245.pdf"><span>40 CFR 1065.245 - <span class="hlt">Sample</span> flow meter for batch <span class="hlt">sampling</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.245... difference between a diluted exhaust <span class="hlt">sample</span> flow meter and a dilution <span class="hlt">air</span> meter to calculate raw exhaust flow...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol34/pdf/CFR-2013-title40-vol34-sec1065-245.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol34/pdf/CFR-2013-title40-vol34-sec1065-245.pdf"><span>40 CFR 1065.245 - <span class="hlt">Sample</span> flow meter for batch <span class="hlt">sampling</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.245... difference between a diluted exhaust <span class="hlt">sample</span> flow meter and a dilution <span class="hlt">air</span> meter to calculate raw exhaust flow...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1065-245.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1065-245.pdf"><span>40 CFR 1065.245 - <span class="hlt">Sample</span> flow meter for batch <span class="hlt">sampling</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.245... difference between a diluted exhaust <span class="hlt">sample</span> flow meter and a dilution <span class="hlt">air</span> meter to calculate raw exhaust flow...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16125287','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16125287"><span>Monitoring iodine-129 in <span class="hlt">air</span> and milk <span class="hlt">samples</span> collected near the Hanford Site: an investigation of historical iodine monitoring data.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fritz, Brad G; Patton, Gregory W</p> <p>2006-01-01</p> <p>While other research has reported on the concentrations of (129)I in the environment surrounding active nuclear fuel reprocessing facilities, there is a shortage of information regarding how the concentrations change once facilities close. At the Hanford Site, the Plutonium-Uranium Extraction (PUREX) chemical separation plant was operating between 1983 and 1990, during which time (129)I concentrations in <span class="hlt">air</span> and milk were measured. After the cessation of chemical processing, plant emissions decreased 2.5 orders of magnitude over an 8-year period. An evaluation of (129)I and (127)I concentration data in <span class="hlt">air</span> and milk spanning the PUREX operation and post-closure period was conducted to compare the changes in environmental levels. Measured concentrations over the monitoring period were below the levels that could result in a potential annual human dose greater than 1 mSv. There was a measurable difference in the measured <span class="hlt">air</span> concentrations of (129)I at different distances from the source, indicating a distinct Hanford fingerprint. Correlations between stack emissions of (129)I and concentrations in <span class="hlt">air</span> and milk indicate that atmospheric emissions were the major source of (129)I measured in environmental <span class="hlt">samples</span>. The measured concentrations during PUREX operations were similar to observations made around a fuel reprocessing plant in Germany. After the PUREX Plant stopped operating, (129)I concentration measurements made upwind of Hanford were similar to the results from Seville, Spain.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/876836-monitoring-iodine-air-milk-samples-collected-near-hanford-site-investigation-historical-iodine-monitoring-data','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/876836-monitoring-iodine-air-milk-samples-collected-near-hanford-site-investigation-historical-iodine-monitoring-data"><span>Monitoring Iodine-129 in <span class="hlt">Air</span> and Milk <span class="hlt">Samples</span> Collected Near the Hanford Site: An Investigation of Historical Iodine Monitoring Data</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Fritz, Brad G.; Patton, Gregory W.</p> <p>2006-01-01</p> <p>While other research has reported on the concentrations of 129I in the environment surrounding active nuclear fuel reprocessing facilities, there is a shortage of information regarding how the concentrations change once facilities close. At the Hanford Site, the Plutonium-Uranium Extraction (PUREX) chemical separation plant was operational between 1983 and 1990, during which time 129I concentrations in <span class="hlt">air</span> and milk were measured. After the cessation of operations in 1990, plant emissions decreased 2.5 orders of magnitude over an 8 year period, and monitoring of environmental levels continued. An evaluation of <span class="hlt">air</span> and milk 129I concentration data spanning the PUREX operation andmore » post closure period was conducted to compare the changes in environmental levels of 129I measured. Measured concentrations over the monitoring period were below levels that could result in a potential human dose greater than 10 uSv. There was a significant and measurable difference in the measured <span class="hlt">air</span> concentrations of 129I at different distances from the source, indicating a distinct Hanford fingerprint. Correlations between stack emissions of 129I and concentrations in <span class="hlt">air</span> and milk indicate that atmospheric emissions were responsible for the 129I concentrations measured in environmental <span class="hlt">samples</span>. The measured concentrations during PUREX operation were similar to observations made around a fuel reprocessing plant in Germany.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1014368','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1014368"><span>Soil separator and sampler and method of <span class="hlt">sampling</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>O'Brien, Barry H [Idaho Falls, ID; Ritter, Paul D [Idaho Falls, ID</p> <p>2010-02-16</p> <p>A soil sampler includes a fluidized bed for receiving a soil <span class="hlt">sample</span>. The fluidized bed may be in communication with a vacuum for drawing <span class="hlt">air</span> through the fluidized bed and suspending particulate matter of the soil <span class="hlt">sample</span> in the <span class="hlt">air</span>. In a method of <span class="hlt">sampling</span>, the <span class="hlt">air</span> may be drawn across a filter, separating the particulate matter. Optionally, a baffle or a cyclone may be included within the fluidized bed for disentrainment, or dedusting, so only the finest particulate matter, including asbestos, will be trapped on the filter. The filter may be removable, and may be tested to determine the content of asbestos and other hazardous particulate matter in the soil <span class="hlt">sample</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930032550&hterms=sampling+distribution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsampling%2Bdistribution','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930032550&hterms=sampling+distribution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsampling%2Bdistribution"><span>Beryllium 7 and lead 210 in the Western Hemisphere Arctic atmosphere - Observations from three recent aircraft-based <span class="hlt">sampling</span> programs</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dibb, Jack E.; Talbot, Robert W.; Gregory, Gerald L.</p> <p>1992-01-01</p> <p>Concentrations of the natural radionuclides Be-7 and Pb-210 in the Western Hemisphere Arctic atmosphere were determined during the recent NOAA Arctic Gas and Aerosol <span class="hlt">Sampling</span> Program (AGASP 3) and NASA Global Tropospheric Experiment/Arctic Boundary Layer Expeditions (GTE/ABLE 3A and ABLE 3B) missions. Be-7 concentrations measured during the AGASP 3 mission north and west of Norway are in accord with previous results for high northern latitudes, but suggest that the 'stratospheric' <span class="hlt">air</span> masses <span class="hlt">sampled</span> at the highest elevations reached were significantly diluted with tropospheric <span class="hlt">air</span>. Higher resolution <span class="hlt">sampling</span> in the free troposphere of the North American Arctic during ABLE 3B <span class="hlt">revealed</span> a layer of elevated Be-7 concentrations near 5 km. The distribution of Pb-210 in the high-altitude troposphere of North America during the summer was quite similar to distributions of more frequently measured aerosol species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4406252','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4406252"><span>Improved Atmospheric <span class="hlt">Sampling</span> of Hexavalent Chromium</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Torkmahalleh, Mehdi Amouei; Yu, Chang-Ho; Lin, Lin; Fan, Zhihua (Tina); Swift, Julie L.; Bonanno, Linda; Rasmussen, Don H.; Holsen, Thomas M.; Hopke, Philip K.</p> <p>2015-01-01</p> <p>Hexavalent chromium (Cr(VI)) and trivalent chromium (Cr(III)) are the primary chromium oxidation states found in ambient atmospheric particulate matter. While Cr(III) is relatively nontoxic, Cr(VI) is toxic and exposure to Cr(VI) may lead to cancer, nasal damage, asthma, bronchitis, and pneumonitis. Accurate measurement of the ambient Cr(VI) concentrations is an environmental challenge since Cr(VI) can be reduced to Cr(III) and vice versa during <span class="hlt">sampling</span>. In the present study, a new Cr(VI) sampler (Clarkson sampler) was designed, constructed, and field tested to improve the <span class="hlt">sampling</span> of Cr(VI) in ambient <span class="hlt">air</span>. The new Clarkson Cr(VI) sampler was based on the concept that deliquescence during <span class="hlt">sampling</span> leads to aqueous phase reactions. Thus, the relative humidity of the <span class="hlt">sampled</span> <span class="hlt">air</span> was reduced below the deliquescence relative humidity (DRH) of the ambient particles. The new sampler was operated to collect Total Suspended Particles (TSP), and compared side-by-side with the current National <span class="hlt">Air</span> Toxics Trends Stations (NATTS) Cr(VI) sampler that is utilized in the United States Environmental Protection Agency (USEPA) <span class="hlt">air</span> toxics monitoring program. Side-by-side field testing of the samplers occurred in Elizabeth, NJ during the winter and summer of 2012. The average recovery values of Cr(VI) spikes after 24 hour <span class="hlt">sampling</span> intervals during summer and winter <span class="hlt">sampling</span> were 57 and 72%, respectively, for the Clarkson sampler, while the corresponding average values for NATTS samplers were 46% for both summer and winter <span class="hlt">sampling</span>, respectively. Preventing the ambient aerosol collected on the filters from deliquescing is a key to improving the <span class="hlt">sampling</span> of Cr(VI). PMID:24344574</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1389354','SCIGOV-DOEDE'); return false;" href="https://www.osti.gov/servlets/purl/1389354"><span>Atmospheric CO2 Records from Sites in the Umweltbundesamt (UBA) <span class="hlt">Air</span> <span class="hlt">Sampling</span> Network (1972 - 1997)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/dataexplorer">DOE Data Explorer</a></p> <p>Fricke, W. [Umweltbundesamt, Offenbach/Main, Germany; Wallasch, M. [Umweltbundesamt, Offenbach/Main, Germany; Uhse, Karin [Umweltbundesamt, Offenbach/Main, Germany; Schmidt, Martina [University of Heidelberg, Heidelberg, Germany; Levin, Ingeborg [University of Heidelberg, Heidelberg, Germany</p> <p>1998-01-01</p> <p><span class="hlt">Air</span> <span class="hlt">samples</span> for the purpose of monitoring atmospheric CO2 were collected from five sites in the UBA <span class="hlt">air</span> <span class="hlt">sampling</span> network. Annual atmospheric CO2 concentrations at Brotjacklriegel rose from 331.63 parts per million by volume (ppmv) in 1972 to 353.12 ppmv in 1988. Because of the site's forest location, the monthly atmospheric CO2 record from Brotjacklriegel exhibits very large seasonal amplitude. This amplitude reached almost 40 ppmv in 1985. Minimum mixing ratios are recorded at Brotjacklriegel during July-September; maximum values, during November-March. CO2 concentrations at Deuselbach rose from 340.82 parts per million by volume (ppmv) in 1972 to 363.76 ppmv in 1989. The monthly atmospheric CO2 record from Deuselbach is influenced by local agricultural activities and photosynthetic depletion but does not exhibit the large seasonal amplitude observed at other UBA monitoring sites. Minimum monthly atmospheric CO2 mixing ratios at Deuselbach are typically observed in August but may appear as early as June. Maximum values are seen in the record for November-March. Atmospheric CO2 concentrations at Schauinsland rose from ~328 parts per million by volume (ppmv) in 1972 to ~365 ppmv in 1997. This represents a growth rate of approximately 1.5 ppmv per year. The Schauinsland site is considered the least contaminated of the UBA sites. CO2 concentrations at Waldhof rose from 346.82 parts per million by volume (ppmv) in 1972 to 372.09 ppmv in 1993. The Waldhof site is subject to pollution sources; consequently, the monthly atmospheric CO2 record exhibits a large seasonal amplitude. Atmospheric CO2 concentrations at Westerland rose from ~329 parts per million by volume (ppmv) in 1973 to ~364 ppmv in 1997. The atmospheric CO2 record from Westerland shows a seasonal pattern similar to other UBA sites; minimum values are recorded during July-September; maximum mixing ratios during November-March.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920015590&hterms=Metal+oxide+film+Metal+oxide+film+Metal+oxide+film&qs=N%3D0%26Ntk%3DAll%7CTitle%26Ntx%3Dmode%2Bmatchall%257Cmode%2Bmatchall%26Ntt%3DMetal%2Boxide%2Bfilm%257CMetal%2Boxide%2Bfilm','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920015590&hterms=Metal+oxide+film+Metal+oxide+film+Metal+oxide+film&qs=N%3D0%26Ntk%3DAll%7CTitle%26Ntx%3Dmode%2Bmatchall%257Cmode%2Bmatchall%26Ntt%3DMetal%2Boxide%2Bfilm%257CMetal%2Boxide%2Bfilm"><span>Ellipsometric study of oxide films formed on LDEF metal <span class="hlt">samples</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Franzen, W.; Brodkin, J. S.; Sengupta, L. C.; Sagalyn, P. L.</p> <p>1992-01-01</p> <p>The optical constants of <span class="hlt">samples</span> of six different metals (Al, Cu, Ni, Ta, W, and Zr) exposed to space on the Long Duration Exposure Facility (LDEF) were studied by variable angle spectroscopic ellipsometry. Measurements were also carried out on portions of each <span class="hlt">sample</span> which were shielded from direct exposure by a metal bar. A least-squares fit of the data using an effective medium approximation was then carried out, with thickness and composition of surface films formed on the metal substrates as variable parameters. The analysis <span class="hlt">revealed</span> that exposed portions of the Cu, Ni, Ta, and Zr <span class="hlt">samples</span> are covered with porous oxide films ranging in thickness from 500 to 1000 A. The 410 A thick film of Al2O3 on the exposed Al <span class="hlt">sample</span> is practically free of voids. Except for Cu, the shielded portions of these metals are covered by thin non-porous oxide films characteristic of exposure to <span class="hlt">air</span>. The shielded part of the Cu <span class="hlt">sample</span> has a much thicker porous coating of Cu2O. The tungsten data could not be analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869087','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/869087"><span><span class="hlt">Sample</span> introducing apparatus and <span class="hlt">sample</span> modules for mass spectrometer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Thompson, Cyril V.; Wise, Marcus B.</p> <p>1993-01-01</p> <p>An apparatus for introducing gaseous <span class="hlt">samples</span> from a wide range of environmental matrices into a mass spectrometer for analysis of the <span class="hlt">samples</span> is described. Several <span class="hlt">sample</span> preparing modules including a real-time <span class="hlt">air</span> monitoring module, a soil/liquid purge module, and a thermal desorption module are individually and rapidly attachable to the <span class="hlt">sample</span> introducing apparatus for supplying gaseous <span class="hlt">samples</span> to the mass spectrometer. The <span class="hlt">sample</span>-introducing apparatus uses a capillary column for conveying the gaseous <span class="hlt">samples</span> into the mass spectrometer and is provided with an open/split interface in communication with the capillary and a <span class="hlt">sample</span> archiving port through which at least about 90 percent of the gaseous <span class="hlt">sample</span> in a mixture with an inert gas that was introduced into the <span class="hlt">sample</span> introducing apparatus is separated from a minor portion of the mixture entering the capillary discharged from the <span class="hlt">sample</span> introducing apparatus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70025095','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70025095"><span>Corn leaf nitrate reductase - A nontoxic alternative to cadmium for photometric nitrate determinations in water <span class="hlt">samples</span> by <span class="hlt">air</span>-segmented continuous-flow analysis</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Patton, C.J.; Fischer, A.E.; Campbell, W.H.; Campbell, E.R.</p> <p>2002-01-01</p> <p>Development, characterization, and operational details of an enzymatic, <span class="hlt">air</span>-segmented continuous-flow analytical method for colorimetric determination of nitrate + nitrite in natural-water <span class="hlt">samples</span> is described. This method is similar to U.S. Environmental Protection Agency method 353.2 and U.S. Geological Survey method 1-2545-90 except that nitrate is reduced to nitrite by soluble nitrate reductase (NaR, EC 1.6.6.1) purified from corn leaves rather than a packed-bed cadmium reactor. A three-channel, <span class="hlt">air</span>-segmented continuous-flow analyzer-configured for simultaneous determination of nitrite (0.020-1.000 mg-N/L) and nitrate + nitrite (0.05-5.00 mg-N/L) by the nitrate reductase and cadmium reduction methods-was used to characterize analytical performance of the enzymatic reduction method. At a <span class="hlt">sampling</span> rate of 90 h-1, <span class="hlt">sample</span> interaction was less than 1% for all three methods. Method detection limits were 0.001 mg of NO2- -N/L for nitrite, 0.003 mg of NO3-+ NO2- -N/L for nitrate + nitrite by the cadmium-reduction method, and 0.006 mg of NO3- + NO2- -N/L for nitrate + nitrite by the enzymatic-reduction method. Reduction of nitrate to nitrite by both methods was greater than 95% complete over the entire calibration range. The difference between the means of nitrate + nitrite concentrations in 124 natural-water <span class="hlt">samples</span> determined simultaneously by the two methods was not significantly different from zero at the p = 0.05 level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=methane&id=EJ963136','ERIC'); return false;" href="https://eric.ed.gov/?q=methane&id=EJ963136"><span>Measurement of <span class="hlt">Air</span> Pollutants in the Troposphere</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Clemitshaw, Kevin C.</p> <p>2011-01-01</p> <p>This article describes the principles, applications and performances of methods to measure gas-phase <span class="hlt">air</span> pollutants that either utilise passive or active <span class="hlt">sampling</span> with subsequent laboratory analysis or involve automated "in situ" <span class="hlt">sampling</span> and analysis. It focuses on <span class="hlt">air</span> pollutants that have adverse impacts on human health (nitrogen…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4449033','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4449033"><span>Chamber Bioaerosol Study: Outdoor <span class="hlt">Air</span> and Human Occupants as Sources of Indoor Airborne Microbes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Adams, Rachel I.; Bhangar, Seema; Pasut, Wilmer; Arens, Edward A.; Taylor, John W.; Lindow, Steven E.; Nazaroff, William W.; Bruns, Thomas D.</p> <p>2015-01-01</p> <p>Human occupants are an important source of microbes in indoor environments. In this study, we used DNA sequencing of filter <span class="hlt">samples</span> to assess the fungal and bacterial composition of <span class="hlt">air</span> in an environmental chamber under different levels of occupancy, activity, and exposed or covered carpeting. In this office-like, mechanically ventilated environment, results showed a strong influence of outdoor-derived particles, with the indoor microbial composition tracking that of outdoor <span class="hlt">air</span> for the 2-hour <span class="hlt">sampling</span> periods. The number of occupants and their activity played a significant but smaller role influencing the composition of indoor bioaerosols. Human-associated taxa were observed but were not particularly abundant, except in the case of one fungus that appeared to be transported into the chamber on the clothing of a study participant. Overall, this study <span class="hlt">revealed</span> a smaller signature of human body-associated taxa than had been expected based on recent studies of indoor microbiomes, suggesting that occupants may not exert a strong influence on bioaerosol microbial composition in a space that, like many offices, is well ventilated with <span class="hlt">air</span> that is moderately filtered and moderately occupied. PMID:26024222</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6503928-evaluation-silica-gel-cartridges-coated-situ-acidified-dinitrophenylhydrazine-sampling-aldehydes-ketones-air','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6503928-evaluation-silica-gel-cartridges-coated-situ-acidified-dinitrophenylhydrazine-sampling-aldehydes-ketones-air"><span>Evaluation of silica-gel cartridges coated in situ with acidified 2,4-dinitrophenylhydrazine for <span class="hlt">sampling</span> aldehydes and ketones in <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Tejada, S.B.</p> <p>1986-01-01</p> <p>A procedure for coating in-situ silica in commercially available prepacked cartridges with 2,4-dinitrophenylhydrazine (DNPH) acidified with hydrochloric acid is described. The coated cartridge was compared with a validated DNPH impinger method for <span class="hlt">sampling</span> organic carbonyl compounds (aldehydes and ketones) in diluted automotive exhaust emissions and in ambient <span class="hlt">air</span> for subsequent analysis of the DNPH derivatives by high performance liquid chromatography. Qualitative and quantitative results show that the two <span class="hlt">sampling</span> devices are equivalent. An unknown degradation product of acrolein has been tentatively identified as x-acrolein. The disappearance of acrolein in the analytical <span class="hlt">sample</span> matrix correlated quantitatively almost on a mole-for-mole basismore » with the growth of x-acrolein. The sum of the concentration of acrolein and x-acrolein appears to be invariant with time. This sum could possibly be used as a more-accurate value of the concentration of acrolein in the integratated <span class="hlt">sample</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5898193-urban-air-toxics-monitoring-program','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5898193-urban-air-toxics-monitoring-program"><span>Urban <span class="hlt">Air</span> Toxics Monitoring Program, 1989</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>McAllister, R.A.; Moore, W.H.; Rice, J.</p> <p>1990-10-01</p> <p>From January 1989 through January 1990 <span class="hlt">samples</span> of ambient <span class="hlt">air</span> were collected at 14 sites in the eastern part of the U.S. Every 12 days, <span class="hlt">air</span> was integrated over 24-hour periods into passivated stainless steel canisters. Simultaneously, <span class="hlt">air</span> was drawn through cartridges containing dinitrophenylhydrazine to collect carbonyl compounds. The <span class="hlt">samples</span> were analyzed at a central laboratory for a total of 37 halogenated and aromatic hydrocarbons, formaldehyde, acetaldehyde, and other oxygenated species. The hydrocarbon species were analyzed by gas chromatography/multiple detectors and gas chromatography/mass spectrometry, while the carbonyl species were analyzed by liquid chromatography. An extensive quality assurance program was carriedmore » on to secure high quality data. Complete data for all the carbonyl <span class="hlt">samples</span> are presented in the report.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JNuM..374..123L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JNuM..374..123L"><span>Change of properties after oxidation of IG-11 graphite by <span class="hlt">air</span> and CO 2 gas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lim, Yun-Soo; Chi, Se-Hwan; Cho, Kwang-Yun</p> <p>2008-02-01</p> <p>Artificial graphite is typically manufactured by carbonization of a shaped body of a kneaded mixture using granular cokes as a filler and pitch as a binder. It undergoes a pitch impregnation process if necessary and finally applying graphitization heat treatment. The effect of thermal oxidation in <span class="hlt">air</span> or a CO 2 atmosphere on IG-11 graphite <span class="hlt">samples</span> is investigated in this study. The results show a localized oxidation process that progressively <span class="hlt">reveals</span> the large coke particles with increasing level of overall weight loss in <span class="hlt">air</span>. The surface of the graphite was peeled off and no change was found in the specific gravity after <span class="hlt">air</span> oxidation. However, the specific gravity of graphite was continuously decreased by CO 2 oxidation. The decrease in the specific gravity by CO 2 oxidation was due to CO 2 gas that progressed from the surface to the interior. The pore shape after CO 2 oxidation differed from that under <span class="hlt">air</span> oxidation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhDT.......166M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT.......166M"><span>Incident-response monitoring technologies for aircraft cabin <span class="hlt">air</span> quality</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Magoha, Paul W.</p> <p></p> <p> from BAS tests by optical particle counter (OPC) <span class="hlt">revealed</span> lognormal distributions with the mean (range) of geometric mass mean diameter (GMMD) = 0.41 (0.39, 0.45) microm and geometric standard deviation (GSD), sigma g = 1.92 (1.87, 1.98). FESEM/EDS and NAA techniques found a wide range of elements on filters, and further investigations of used filters are recommended using these techniques. The protocols for <span class="hlt">air</span> and filter <span class="hlt">sampling</span> and GC/MS analysis used in this study will increase the options available for detecting jet engine oil on cabin <span class="hlt">air</span> filters. Such criteria could support policy development for compliance with cabin <span class="hlt">air</span> quality standards during incidents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5619676','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/5619676"><span>Perfluorocarbon tracer method for <span class="hlt">air</span>-infiltration measurements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Dietz, R.N.</p> <p>1982-09-23</p> <p>A method of measuring <span class="hlt">air</span> infiltration rates suitable for use in rooms of homes and buildings comprises the steps of emitting perfluorocarbons in the room to be measured, <span class="hlt">sampling</span> the <span class="hlt">air</span> containing the emitted perfluorocarbons over a period of time, and analyzing the <span class="hlt">samples</span> at a laboratory or other facility.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol21/pdf/CFR-2013-title40-vol21-sec91-420.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol21/pdf/CFR-2013-title40-vol21-sec91-420.pdf"><span>40 CFR 91.420 - CVS concept of exhaust gas <span class="hlt">sampling</span> system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... that complete mixing of the engine exhaust and background <span class="hlt">air</span> is assured prior to the <span class="hlt">sampling</span> probe.... The background probe must draw a representative <span class="hlt">sample</span> of the background <span class="hlt">air</span> during each <span class="hlt">sampling</span> mode...) <span class="hlt">sampling</span> system. If a critical flow venturi (CFV) is used on the dilute exhaust <span class="hlt">sample</span> probe, this system...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol20/pdf/CFR-2010-title40-vol20-sec91-420.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol20/pdf/CFR-2010-title40-vol20-sec91-420.pdf"><span>40 CFR 91.420 - CVS concept of exhaust gas <span class="hlt">sampling</span> system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... that complete mixing of the engine exhaust and background <span class="hlt">air</span> is assured prior to the <span class="hlt">sampling</span> probe.... The background probe must draw a representative <span class="hlt">sample</span> of the background <span class="hlt">air</span> during each <span class="hlt">sampling</span> mode...) <span class="hlt">sampling</span> system. If a critical flow venturi (CFV) is used on the dilute exhaust <span class="hlt">sample</span> probe, this system...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol20/pdf/CFR-2014-title40-vol20-sec91-420.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol20/pdf/CFR-2014-title40-vol20-sec91-420.pdf"><span>40 CFR 91.420 - CVS concept of exhaust gas <span class="hlt">sampling</span> system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... that complete mixing of the engine exhaust and background <span class="hlt">air</span> is assured prior to the <span class="hlt">sampling</span> probe.... The background probe must draw a representative <span class="hlt">sample</span> of the background <span class="hlt">air</span> during each <span class="hlt">sampling</span> mode...) <span class="hlt">sampling</span> system. If a critical flow venturi (CFV) is used on the dilute exhaust <span class="hlt">sample</span> probe, this system...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol20/pdf/CFR-2011-title40-vol20-sec91-420.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol20/pdf/CFR-2011-title40-vol20-sec91-420.pdf"><span>40 CFR 91.420 - CVS concept of exhaust gas <span class="hlt">sampling</span> system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... that complete mixing of the engine exhaust and background <span class="hlt">air</span> is assured prior to the <span class="hlt">sampling</span> probe.... The background probe must draw a representative <span class="hlt">sample</span> of the background <span class="hlt">air</span> during each <span class="hlt">sampling</span> mode...) <span class="hlt">sampling</span> system. If a critical flow venturi (CFV) is used on the dilute exhaust <span class="hlt">sample</span> probe, this system...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol21/pdf/CFR-2012-title40-vol21-sec91-420.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol21/pdf/CFR-2012-title40-vol21-sec91-420.pdf"><span>40 CFR 91.420 - CVS concept of exhaust gas <span class="hlt">sampling</span> system.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... that complete mixing of the engine exhaust and background <span class="hlt">air</span> is assured prior to the <span class="hlt">sampling</span> probe.... The background probe must draw a representative <span class="hlt">sample</span> of the background <span class="hlt">air</span> during each <span class="hlt">sampling</span> mode...) <span class="hlt">sampling</span> system. If a critical flow venturi (CFV) is used on the dilute exhaust <span class="hlt">sample</span> probe, this system...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19730004','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19730004"><span>The relationships between <span class="hlt">air</span> exposure, negative pressure, and hemolysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pohlmann, Joshua R; Toomasian, John M; Hampton, Claire E; Cook, Keith E; Annich, Gail M; Bartlett, Robert H</p> <p>2009-01-01</p> <p>The purpose of this study was to describe the hemolytic effects of both negative pressure and an <span class="hlt">air</span>-blood interface independently and in combination in an in vitro static blood model. <span class="hlt">Samples</span> of fresh ovine or human blood (5 ml) were subjected to a bubbling <span class="hlt">air</span> interface (0-100 ml/min) or negative pressure (0-600 mm Hg) separately, or in combination, for controlled periods of time and analyzed for hemolysis. Neither negative pressure nor an <span class="hlt">air</span> interface alone increased hemolysis. However, when <span class="hlt">air</span> and negative pressure were combined, hemolysis increased as a function of negative pressure, the <span class="hlt">air</span> interface, and time. Moreover, when blood <span class="hlt">samples</span> were exposed to <span class="hlt">air</span> before initiating the test, hemolysis was four to five times greater than <span class="hlt">samples</span> not preexposed to <span class="hlt">air</span>. When these experiments were repeated using freshly drawn human blood, the same phenomena were observed, but the hemolysis was significantly higher than that observed in sheep blood. In this model, hemolysis is caused by combined <span class="hlt">air</span> and negative pressure and is unrelated to either factor alone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3662481','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3662481"><span>The Relationships between <span class="hlt">Air</span> Exposure, Negative Pressure and Hemolysis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pohlmann, Joshua R.; Toomasian, John M.; Hampton, Claire E.; Cook, Keith E.; Annich, Gail M.; Bartlett, Robert H.</p> <p>2013-01-01</p> <p>The purpose of this study was to describe the hemolytic effects of both negative pressure and an <span class="hlt">air</span>-blood interface independently and in combination in an in-vitro static blood model. <span class="hlt">Samples</span> of fresh ovine or human blood (5 mL) were subjected to a bubbling <span class="hlt">air</span> interface (0–100 mL/min) or negative pressure (0–600 mmHg) separately, or in combination, for controlled periods of time, and analyzed for hemolysis. Neither negative pressure nor an <span class="hlt">air</span> interface alone increased hemolysis. However, when <span class="hlt">air</span> and negative pressure were combined, hemolysis increased as a function of negative pressure, the <span class="hlt">air</span> interface, and time. Moreover, when blood <span class="hlt">samples</span> were exposed to <span class="hlt">air</span> prior to initiating the test, hemolysis was 4–5 times greater than <span class="hlt">samples</span> not pre-exposed to <span class="hlt">air</span>. When these experiments were repeated using freshly drawn human blood the same phenomena were observed, but the hemolysis was significantly higher than that observed in sheep blood. In this model, hemolysis is caused by combined <span class="hlt">air</span> and negative pressure and is unrelated to either factor alone. PMID:19730004</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.epa.gov/radnet/radnet-sampling-and-analyses-schedules','PESTICIDES'); return false;" href="https://www.epa.gov/radnet/radnet-sampling-and-analyses-schedules"><span>RadNet <span class="hlt">Sampling</span> and Analyses Schedules</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>RadNet <span class="hlt">air</span> monitors operate continuously and <span class="hlt">samples</span> of <span class="hlt">air</span>, precipitation and drinking water and analyzed on a routine schedule. RadNet can send deployable monitors to any U.S. location in the case of a radiological emergency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AIPC.1497...61M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AIPC.1497...61M"><span>Evaluation of indoor <span class="hlt">air</span> composition time variation in <span class="hlt">air</span>-tight occupied spaces during night periods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Markov, Detelin</p> <p>2012-11-01</p> <p>This paper presents an easy-to-understand procedure for prediction of indoor <span class="hlt">air</span> composition time variation in <span class="hlt">air</span>-tight occupied spaces during the night periods. The mathematical model is based on the assumptions for homogeneity and perfect mixing of the indoor <span class="hlt">air</span>, the ideal gas model for non-reacting gas mixtures, mass conservation equations for the entire system and for each species, a model for prediction of basal metabolic rate of humans as well as a model for prediction of O2 consumption rate and both CO2 and H2O generation rates by breathing. Time variation of indoor <span class="hlt">air</span> composition is predicted at constant indoor <span class="hlt">air</span> temperature for three scenarios based on the analytical solution of the mathematical model. The results achieved <span class="hlt">reveal</span> both the most probable scenario for indoor <span class="hlt">air</span> time variation in <span class="hlt">air</span>-tight occupied spaces as well as the cause for morning tiredness after having a sleep in a modern energy efficient space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28706893','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28706893"><span>Rectal perforation by compressed <span class="hlt">air</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Young Jin</p> <p>2017-07-01</p> <p>As the use of compressed <span class="hlt">air</span> in industrial work has increased, so has the risk of associated pneumatic injury from its improper use. However, damage of large intestine caused by compressed <span class="hlt">air</span> is uncommon. Herein a case of pneumatic rupture of the rectum is described. The patient was admitted to the Emergency Room complaining of abdominal pain and distension. His colleague triggered a compressed <span class="hlt">air</span> nozzle over his buttock. On arrival, vital signs were stable but physical examination <span class="hlt">revealed</span> peritoneal irritation and marked distension of the abdomen. Computed tomography showed a large volume of <span class="hlt">air</span> in the peritoneal cavity and subcutaneous emphysema at the perineum. A rectal perforation was found at laparotomy and the Hartmann procedure was performed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5437310','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/5437310"><span><span class="hlt">Sample</span> introducing apparatus and <span class="hlt">sample</span> modules for mass spectrometer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Thompson, C.V.; Wise, M.B.</p> <p>1993-12-21</p> <p>An apparatus for introducing gaseous <span class="hlt">samples</span> from a wide range of environmental matrices into a mass spectrometer for analysis of the <span class="hlt">samples</span> is described. Several <span class="hlt">sample</span> preparing modules including a real-time <span class="hlt">air</span> monitoring module, a soil/liquid purge module, and a thermal desorption module are individually and rapidly attachable to the <span class="hlt">sample</span> introducing apparatus for supplying gaseous <span class="hlt">samples</span> to the mass spectrometer. The <span class="hlt">sample</span>-introducing apparatus uses a capillary column for conveying the gaseous <span class="hlt">samples</span> into the mass spectrometer and is provided with an open/split interface in communication with the capillary and a <span class="hlt">sample</span> archiving port through which at least about 90 percent of the gaseous <span class="hlt">sample</span> in a mixture with an inert gas that was introduced into the <span class="hlt">sample</span> introducing apparatus is separated from a minor portion of the mixture entering the capillary discharged from the <span class="hlt">sample</span> introducing apparatus. 5 figures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060044142&hterms=endotoxin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dendotoxin','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060044142&hterms=endotoxin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dendotoxin"><span>Microbial assessment of cabin <span class="hlt">air</span> quality on commercial airliners</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>La Duc, Myron T.; Stuecker, Tara; Bearman, Gregory; Venkateswaran, Kasthuri</p> <p>2005-01-01</p> <p>The microbial burdens of 69 cabin <span class="hlt">air</span> <span class="hlt">samples</span> collected from commercial airliners were assessed via conventional culture-dependent, and molecular-based microbial enumeration assays. Cabin <span class="hlt">air</span> <span class="hlt">samples</span> from each of four separate flights aboard two different carriers were collected via <span class="hlt">air</span>-impingement. Microbial enumeration techniques targeting DNA, ATP, and endotoxin were employed to estimate total microbial burden. The total viable microbial population ranged from 0 to 3.6 x10 4 cells per 100 liters of <span class="hlt">air</span>, as assessed by the ATP-assay. When these same <span class="hlt">samples</span> were plated on R2A minimal medium, anywhere from 2% to 80% of these viable populations were cultivable. Five of the 29 <span class="hlt">samples</span> examined exhibited higher cultivable counts than ATP derived viable counts, perhaps a consequence of the dormant nature (and thus lower concentration of intracellular ATP) of cells inhabiting these <span class="hlt">air</span> cabin <span class="hlt">samples</span>. Ribosomal RNA gene sequence analysis showed these <span class="hlt">samples</span> to consist of a moderately diverse group of bacteria, including human pathogens. Enumeration of ribosomal genes via quantitative-PCR indicated that population densities ranged from 5 x 10 1 ' to IO 7 cells per 100 liters of <span class="hlt">air</span>. Each of the aforementioned strategies for assessing overall microbial burden has its strengths and weaknesses; this publication serves as a testament to the power of their use in concert.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=22902&Lab=NERL&keyword=urine+AND+sample+AND+storage&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=22902&Lab=NERL&keyword=urine+AND+sample+AND+storage&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>NHEXAS PHASE I MARYLAND STUDY--PESTICIDES IN <span class="hlt">AIR</span> ANALYTICAL RESULTS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The Pesticides in <span class="hlt">Air</span> data set contains analytical results for measurements of up to 9 pesticides in 127 <span class="hlt">air</span> <span class="hlt">samples</span> over 51 households. <span class="hlt">Samples</span> were taken by pumping standardized <span class="hlt">air</span> volumes through URG impactors with a 10 um cutpoint and polyurethane foam (PUF) filters at indo...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28693104','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28693104"><span>New insight into the distribution pattern, levels, and risk diagnosis of FRs in indoor and outdoor <span class="hlt">air</span> at low- and high-altitude zones of Pakistan: Implications for sources and exposure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Khan, Muhammad Usman; Besis, Athanasios; Li, Jun; Zhang, Gan; Malik, Riffat Naseem</p> <p>2017-10-01</p> <p>Data regarding flame retardants (FRs) in indoor and outdoor <span class="hlt">air</span> and their exposure to population are scarce and especially unknown in the case of Pakistan. The current study was designed to probe FR concentrations and distribution pattern in indoor and outdoor <span class="hlt">air</span> at different altitudinal zones (DAZs) of Pakistan with special emphasis on their risk to the exposed population. In this study, passive <span class="hlt">air</span> samplers for the purpose of FR deposition were deployed in indoor and outdoor <span class="hlt">air</span> at the industrial, rural, and background/colder zones/sites. All the indoor and outdoor <span class="hlt">air</span> <span class="hlt">samples</span> collected from DAZs were analyzed for the target FRs (9.30-472.30 pg/m 3 ), showing a decreasing trend as follows: ∑NBFRs > ∑PBDEs > ∑DP. However, significant correlations among FRs in the indoor and outdoor <span class="hlt">air</span> at DAZs signified a similar source of FR origin that is used in different consumer goods. Furthermore, <span class="hlt">air</span> mass trajectories <span class="hlt">revealed</span> that movement of <span class="hlt">air</span> over industrial area sources influenced concentrations of FRs at rural sites. The FR concentrations, estimated daily intake (EDI) and the hazard quotient (HQ), were recorded to be higher in toddlers than those in adults. In addition, indoor <span class="hlt">air</span> <span class="hlt">samples</span> showed higher FR levels, EDI and HQ, than outdoor <span class="hlt">air</span> <span class="hlt">samples</span>. An elevated FR concentrations and their prevalent exposure risks were recorded in the industrial zones followed by rural and background zones. The HQ for BDE-47 and BDE-99 in the indoor and outdoor <span class="hlt">air</span> <span class="hlt">samples</span> at different industrial and rural sites were recorded to be >1 in toddlers and adults, this further warrants a health risk in the population. However, FR investigation in indoor and outdoor <span class="hlt">air</span> <span class="hlt">samples</span> will provide a baseline data in Pakistan to take further steps by the government and agencies for its implementations. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12392166','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12392166"><span>Performances and application of a passive <span class="hlt">sampling</span> method for the simultaneous determination of nitrogen dioxide and sulfur dioxide in ambient <span class="hlt">air</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Plaisance, H; Sagnier, I; Saison, J Y; Galloo, J C; Guillermo, R</p> <p>2002-11-01</p> <p>The performances and applicability of a diffusion tube sampler for the simultaneous measurements of NO2 and SO2 in ambient <span class="hlt">air</span> were evaluated. SO2 and NO2 are collected by the passive sampler using triethanolamine as trapping agent and are determined as sulphate and nitrite with ion chromatography. The detection limit (2.3 microg m(-3) of NO2 and 4.2 microg m(-3) of SO2 for two weeks <span class="hlt">sampling</span>) is adequate for the determination of concentrations in urban and industrial areas. Precision of the method as RSD is in mean 5% for NO2 and 12% for SO2 at the concentration levels in urban areas. Calibration of the method was performed in the field conditions by comparison between the responses of sampler and the concentrations measured by the continuous monitors. High degree of linearity (correlation coefficients > 0.8) is found between the passive sampler tube and the continuous monitor data for both NO2 and SO2. To reduce the wind velocity influence on passive <span class="hlt">sampling</span> of diffusion tubes, a protective shelter was tested in this study. The overall uncertainty of one measure for the optimised method is estimated at 5 microg m(-3) for NO2 and 6 microg m(-3) for SO2. Suitability of this passive <span class="hlt">sampling</span> method for <span class="hlt">air</span> pollution monitoring in urban areas was demonstrated by the results shown in this paper on a campaign carried out in the French agglomeration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AcSpe..56..851C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AcSpe..56..851C"><span>On-line analysis of ambient <span class="hlt">air</span> aerosols using laser-induced breakdown spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carranza, J. E.; Fisher, B. T.; Yoder, G. D.; Hahn, D. W.</p> <p>2001-06-01</p> <p>Laser-induced breakdown spectroscopy is developed for the detection of aerosols in ambient <span class="hlt">air</span>, including quantitative mass concentration measurements and size/composition measurements of individual aerosol particles. Data are reported for ambient <span class="hlt">air</span> aerosols containing aluminum, calcium, magnesium and sodium for a 6-week <span class="hlt">sampling</span> period spanning the Fourth of July holiday period. Measured mass concentrations for these four elements ranged from 1.7 parts per trillion (by mass) to 1.7 parts per billion. Ambient <span class="hlt">air</span> concentrations of magnesium and aluminum <span class="hlt">revealed</span> significant increases during the holiday period, which are concluded to arise from the discharge of fireworks in the lower atmosphere. Real-time conditional data analysis yielded increases in analyte spectral intensity approaching 3 orders of magnitude. Analysis of single particles yielded composition-based aerosol size distributions, with measured aerosol diameters ranging from 100 nm to 2 μm. The absolute mass detection limits for single particle analysis exceeded sub-femtogram values for calcium-containing particles, and was on the order of 2-3 femtograms for magnesium and sodium-based particles. Overall, LIBS-based analysis of ambient <span class="hlt">air</span> aerosols is a promising technique for the challenging issues associated with the real-time collection and analysis of ambient <span class="hlt">air</span> particulate matter data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21707676','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21707676"><span>Detection of respiratory viruses on <span class="hlt">air</span> filters from aircraft.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Korves, T M; Johnson, D; Jones, B W; Watson, J; Wolk, D M; Hwang, G M</p> <p>2011-09-01</p> <p>To evaluate the feasibility of identifying viruses from aircraft cabin <span class="hlt">air</span>, we evaluated whether respiratory viruses trapped by commercial aircraft <span class="hlt">air</span> filters can be extracted and detected using a multiplex PCR, bead-based assay. The ResPlex II assay was first tested for its ability to detect inactivated viruses applied to new filter material; all 18 applications of virus at a high concentration were detected. The ResPlex II assay was then used to test for 18 respiratory viruses on 48 used <span class="hlt">air</span> filter <span class="hlt">samples</span> from commercial aircraft. Three <span class="hlt">samples</span> tested positive for viruses, and three viruses were detected: rhinovirus, influenza A and influenza B. For 33 of 48 <span class="hlt">samples</span>, internal PCR controls performed suboptimally, suggesting <span class="hlt">sample</span> matrix effect. In some cases, influenza and rhinovirus RNA can be detected on aircraft <span class="hlt">air</span> filters, even more than 10 days after the filters were removed from aircraft. With protocol modifications to overcome PCR inhibition, <span class="hlt">air</span> filter <span class="hlt">sampling</span> and the ResPlex II assay could be used to characterize viruses in aircraft cabin <span class="hlt">air</span>. Information about viruses in aircraft could support public health measures to reduce disease transmission within aircraft and between cities. © The MITRE corporation. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21730359','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21730359"><span>Determination of tricresyl phosphate <span class="hlt">air</span> contamination in aircraft.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Denola, G; Hanhela, P J; Mazurek, W</p> <p>2011-08-01</p> <p>Monitoring of tricresyl phosphate (TCP) contamination of cockpit <span class="hlt">air</span> was undertaken in three types of military aircraft [fighter trainer (FT), fighter bomber (FB), and cargo transport (CT) aircraft]. The aircraft had a previous history of pilot complaints about cockpit <span class="hlt">air</span> contamination suspected to originate from the engine bleed <span class="hlt">air</span> supply through the entry of aircraft turbine engine oil (ATO) into the engine compressor. <span class="hlt">Air</span> <span class="hlt">samples</span> were collected in flight and on the ground during engine runs using sorbent tubes packed with Porapak Q and cellulose filters. A total of 78 <span class="hlt">air</span> <span class="hlt">samples</span> were analysed, from 46 different aircraft, and 48 <span class="hlt">samples</span> were found to be below the limit of detection. Nine incidents of smoke/odour were identified during the study. The concentrations of toxic o-cresyl phosphate isomers were below the level of detection in all <span class="hlt">samples</span>. The highest total TCP concentration was 51.3 μg m(-3), while most were generally found to be <5 μg m(-3) compared with the 8-h time-weighted average exposure limit of 100 μg m(-3) for tri-o-cresyl phosphate. The highest concentrations were found at high engine power. Although TCP contamination of cabin/cockpit <span class="hlt">air</span> has been the subject of much concern in aviation, quantitative data are sparse.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4031101','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4031101"><span>Time Trends of Polycyclic Aromatic Hydrocarbon Exposure in New York City from 2001 to 2012: Assessed by Repeat <span class="hlt">Air</span> and Urine <span class="hlt">Samples</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jung, Kyung Hwa; Liu, Bian; Lovinsky-Desir, Stephanie; Yan, Beizhan; Camann, David; Sjodin, Andreas; Li, Zheng; Perera, Frederica; Kinney, Patrick; Chillrud, Steven; Miller, Rachel L.</p> <p>2014-01-01</p> <p>Background Exposure to <span class="hlt">air</span> pollutants including polycyclic aromatic hydrocarbons (PAH), and specifically pyrene from combustion of fuel oil, coal, traffic and indoor sources, has been associated with adverse respiratory health outcomes. However, time trends of airborne PAH and metabolite levels detected via repeat measures over time have not yet been characterized. We hypothesized that PAH levels, measured repeatedly from residential indoor and outdoor monitors, and children’s urinary concentrations of PAH metabolites, would decrease following policy interventions to reduce traffic-related <span class="hlt">air</span> pollution. Methods Indoor PAH (particle- and gas-phase) were collected for two weeks prenatally (n=98), at age 5/6 years (n=397) and age 9/10 years (n=198) since 2001 and at all three age-points (n=27). Other traffic-related <span class="hlt">air</span> pollutants (black carbon and PM2.5) were monitored indoors simultaneous with PAH monitoring at ages 5/6 (n=403) and 9/10 (n=257) between 2005 and 2012. One third of the homes were selected across seasons for outdoor PAH, BC and PM2.5 <span class="hlt">sampling</span>. Using the same <span class="hlt">sampling</span> method, ambient PAH, BC and PM2.5 also were monitored every two weeks at a central site between 2007 and 2012. PAH were analyzed as semivolatile PAH (e.g., pyrene; MW 178–206) and the sum of eight nonvolatile PAH (Σ8PAHnonvolatile; MW 228–278). A spot urine <span class="hlt">sample</span> was collected from children at child ages 3, 5, 7 and 9 between 2001 and 2012 and analyzed for 10 PAH metabolites. Results Modest declines were detected in indoor BC and PM2.5 levels between 2005 and 2012 (Annual percent change [APC]=−2.08% [p=0.010] and −2.18% [p=0.059] for BC and PM2.5, respectively), while a trend of increasing pyrene levels was observed in indoor and outdoor <span class="hlt">samples</span>, and at the central site during the comparable time periods (APC=4.81%, 3.77% and 7.90%, respectively; p<0.05 for all). No significant time trend was observed in indoor Σ8PAHnonvolatile levels between 2005 and 2012; however</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100010826','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100010826"><span>STS 129 Return <span class="hlt">Samples</span>: Assessment of <span class="hlt">Air</span> Quality aboard the Shuttle (STS-129) and International Space Station (ULF3)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>James, John T.</p> <p>2010-01-01</p> <p>Reports on the <span class="hlt">air</span> quality aboard the Space Shuttle (STS-129), and the International Space station (ULF3). NASA analyzed the grab <span class="hlt">sample</span> canisters (GSCs) and the formaldehyde badges aboard both locations for carbon monoxide levels. The three surrogates: (sup 13)C-acetone, fluorobenzene, and chlorobenzene registered 109, 101, and 109% in the space shuttle and 81, 87, and 55% in the International Space Station (ISS). From these results the atmosphere in both the Space Shuttle and the International Space Station (ISS) was found to be breathable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=22901&Lab=NERL&keyword=4+AND+hour+AND+work+AND+week&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=22901&Lab=NERL&keyword=4+AND+hour+AND+work+AND+week&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>NHEXAS PHASE I MARYLAND STUDY--PAHS IN <span class="hlt">AIR</span> ANALYTICAL RESULTS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The PAHs in <span class="hlt">Air</span> data set contains analytical results for measurements of up to 11 PAHs in 127 <span class="hlt">air</span> <span class="hlt">samples</span> over 51 households. Twenty-four-hour <span class="hlt">samples</span> were taken over a one-week period using a continuous pump and solenoid apparatus pumping a standardized <span class="hlt">air</span> volume through an UR...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=22900&Lab=NERL&keyword=urine+AND+sample+AND+storage&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=22900&Lab=NERL&keyword=urine+AND+sample+AND+storage&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>NHEXAS PHASE I MARYLAND STUDY--METALS IN <span class="hlt">AIR</span> ANALYTICAL RESULTS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The Metals in <span class="hlt">Air</span> data set contains analytical results for measurements of up to 4 metals in 458 <span class="hlt">air</span> <span class="hlt">samples</span> over 79 households. Twenty-four-hour <span class="hlt">samples</span> were taken over a one-week period using a continuous pump and solenoid apparatus by pumping a standardized <span class="hlt">air</span> volume through...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3616048','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3616048"><span><span class="hlt">Air</span> Quality Monitoring of the Post-Operative Recovery Room and Locations Surrounding Operating Theaters in a Medical Center in Taiwan</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tang, Chin-Sheng; Wan, Gwo-Hwa</p> <p>2013-01-01</p> <p>To prevent surgical site infection (SSI), the airborne microbial concentration in operating theaters must be reduced. The <span class="hlt">air</span> quality in operating theaters and nearby areas is also important to healthcare workers. Therefore, this study assessed <span class="hlt">air</span> quality in the post-operative recovery room, locations surrounding the operating theater area, and operating theaters in a medical center. Temperature, relative humidity (RH), and carbon dioxide (CO2), suspended particulate matter (PM), and bacterial concentrations were monitored weekly over one year. Measurement results <span class="hlt">reveal</span> clear differences in <span class="hlt">air</span> quality in different operating theater areas. The post-operative recovery room had significantly higher CO2 and bacterial concentrations than other locations. Bacillus spp., Micrococcus spp., and Staphylococcus spp. bacteria often existed in the operating theater area. Furthermore, Acinetobacter spp. was the main pathogen in the post-operative recovery room (18%) and traumatic surgery room (8%). The mixed effect models <span class="hlt">reveal</span> a strong correlation between number of people in a space and high CO2 concentration after adjusting for <span class="hlt">sampling</span> locations. In conclusion, <span class="hlt">air</span> quality in the post-operative recovery room and operating theaters warrants attention, and merits long-term surveillance to protect both surgical patients and healthcare workers. PMID:23573296</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23573296','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23573296"><span><span class="hlt">Air</span> quality monitoring of the post-operative recovery room and locations surrounding operating theaters in a medical center in Taiwan.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tang, Chin-Sheng; Wan, Gwo-Hwa</p> <p>2013-01-01</p> <p>To prevent surgical site infection (SSI), the airborne microbial concentration in operating theaters must be reduced. The <span class="hlt">air</span> quality in operating theaters and nearby areas is also important to healthcare workers. Therefore, this study assessed <span class="hlt">air</span> quality in the post-operative recovery room, locations surrounding the operating theater area, and operating theaters in a medical center. Temperature, relative humidity (RH), and carbon dioxide (CO2), suspended particulate matter (PM), and bacterial concentrations were monitored weekly over one year. Measurement results <span class="hlt">reveal</span> clear differences in <span class="hlt">air</span> quality in different operating theater areas. The post-operative recovery room had significantly higher CO2 and bacterial concentrations than other locations. Bacillus spp., Micrococcus spp., and Staphylococcus spp. bacteria often existed in the operating theater area. Furthermore, Acinetobacter spp. was the main pathogen in the post-operative recovery room (18%) and traumatic surgery room (8%). The mixed effect models <span class="hlt">reveal</span> a strong correlation between number of people in a space and high CO2 concentration after adjusting for <span class="hlt">sampling</span> locations. In conclusion, <span class="hlt">air</span> quality in the post-operative recovery room and operating theaters warrants attention, and merits long-term surveillance to protect both surgical patients and healthcare workers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1065-690.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1065-690.pdf"><span>40 CFR 1065.690 - Buoyancy correction for PM <span class="hlt">sample</span> media.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... Buoyancy correction for PM <span class="hlt">sample</span> media. (a) General. Correct PM <span class="hlt">sample</span> media for their buoyancy in <span class="hlt">air</span> if you weigh them on a balance. The buoyancy correction depends on the <span class="hlt">sample</span> media density, the density of <span class="hlt">air</span>, and the density of the calibration weight used to calibrate the balance. The buoyancy...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070023751&hterms=air+asia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dair%2Basia','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070023751&hterms=air+asia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dair%2Basia"><span>High Lapse Rates in <span class="hlt">AIRS</span> Retrieved Temperatures in Cold <span class="hlt">Air</span> Outbreaks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fetzer, Eric J.; Kahn, Brian; Olsen, Edward T.; Fishbein, Evan</p> <p>2004-01-01</p> <p>The Atmospheric Infrared Sounder (<span class="hlt">AIRS</span>) experiment, on NASA's Aqua spacecraft, uses a combination of infrared and microwave observations to retrieve cloud and surface properties, plus temperature and water vapor profiles comparable to radiosondes throughout the troposphere, for cloud cover up to 70%. The high spectral resolution of <span class="hlt">AIRS</span> provides sensitivity to important information about the near-surface atmosphere and underlying surface. A preliminary analysis of <span class="hlt">AIRS</span> temperature retrievals taken during January 2003 <span class="hlt">reveals</span> extensive areas of superadiabatic lapse rates in the lowest kilometer of the atmosphere. These areas are found predominantly east of North America over the Gulf Stream, and, off East Asia over the Kuroshio Current. Accompanying the high lapse rates are low <span class="hlt">air</span> temperatures, large sea-<span class="hlt">air</span> temperature differences, and low relative humidities. Imagery from a Visible / Near Infrared instrument on the <span class="hlt">AIRS</span> experiment shows accompanying clouds. These lines of evidence all point to shallow convection in the bottom layer of a cold <span class="hlt">air</span> mass overlying warm water, with overturning driven by heat flow from ocean to atmosphere. An examination of operational radiosondes at six coastal stations in Japan shows <span class="hlt">AIRS</span> to be oversensitive to lower tropospheric lapse rates due to systematically warm near-surface <span class="hlt">air</span> temperatures. The bias in near-surface <span class="hlt">air</span> temperature is seen to be independent of sea surface temperature, however. <span class="hlt">AIRS</span> is therefore sensitive to <span class="hlt">air</span>-sea temperature difference, but with a warm atmospheric bias. A regression fit to radiosondes is used to correct <span class="hlt">AIRS</span> near-surface retrieved temperatures, and thereby obtain an estimate of the true atmosphere-ocean thermal contrast in five subtropical regions across the north Pacific. Moving eastward, we show a systematic shift in this <span class="hlt">air</span>-sea temperature differences toward more isothermal conditions. These results, while preliminary, have implications for our understanding of heat flow from ocean to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2555227','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2555227"><span>The particles in town <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ellison, J. McK.</p> <p>1965-01-01</p> <p>Particles constitute an important part of <span class="hlt">air</span> pollution, and their behaviour when suspended in <span class="hlt">air</span> is very different from that of gas molecules: in particular, the mechanisms by which they become deposited on surfaces are different, and consequently the methods normally used for removing particles from the <span class="hlt">air</span>, either for <span class="hlt">sampling</span> or for cleaning it, rely mainly on mechanisms that do not enter into the behaviour of gas molecules. These mechanisms are described, and the ways in which they affect the problems of <span class="hlt">air</span> pollution and its measurement are discussed. ImagesFIG. 8 PMID:14315713</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26753167','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26753167"><span>Comparison of halocarbon measurements in an atmospheric dry whole <span class="hlt">air</span> <span class="hlt">sample</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rhoderick, George C; Hall, Bradley D; Harth, Christina M; Kim, Jin Seog; Lee, Jeongsoon; Montzka, Stephen A; Mühle, Jens; Reimann, Stefan; Vollmer, Martin K; Weiss, Ray F</p> <p></p> <p>The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole <span class="hlt">air</span> <span class="hlt">sample</span>. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8913P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8913P"><span>Ice nucleation active particles in continental <span class="hlt">air</span> <span class="hlt">samples</span> over Mainz, Germany</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pummer, Bernhard G.; Pöschl, Ulrich; Fröhlich-Nowoisky, Janine</p> <p>2016-04-01</p> <p>Aerosol particles are of central importance for atmospheric chemistry and physics, climate and public health. Some of these particles possess ice nucleation activity (INA), which is highly relevant for cloud formation and precipitation. In 2010, <span class="hlt">air</span> filter <span class="hlt">samples</span> were collected with a high-volume filter sampler separating fine and coarse particles (aerodynamic cut-off diameter 3 μm) in Mainz, Germany. In this study, the INA of the atmospheric particles deposited on these filters was determined. Therefore,they were extracted with ultrapure water, which was then measured in a droplet freezing assay, as described in Fröhlich-Nowoisky et al. (2015). The determined concentration of ice nucleators (INs) was between 0.3 and 2per m³ at 266 K, and between5 and 75 per m³ at 260 K. The INs were further characterized by different treatments, like heating (308 K, 371 K), filtration (0.1 μm, 300 kDa), and digestion with papain (10 mg/ml). We further investigated, which atmospheric conditions (e.g. weather) and distinguished events (e.g. dust storms, volcanic eruptions, and pollen peaks) influenced the number and nature of these INs. Fröhlich-Nowoisky, J., Hill, T. C. J., Pummer, B. G., Yordanova, P., Franc, G. D., and Pöschl, U.: Ice nucleation activity in the widespread soil fungus Mortierella alpina, Biogeosci., 12, 1057-1071, doi:10.5194/bg-12-1057-2015, 2015.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4702251','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4702251"><span>Comparison of halocarbon measurements in an atmospheric dry whole <span class="hlt">air</span> <span class="hlt">sample</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hall, Bradley D.; Harth, Christina M.; Kim, Jin Seog; Lee, Jeongsoon; Montzka, Stephen A.; Mühle, Jens; Reimann, Stefan; Vollmer, Martin K.; Weiss, Ray F.</p> <p>2015-01-01</p> <p>The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole <span class="hlt">air</span> <span class="hlt">sample</span>. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%. PMID:26753167</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25940477','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25940477"><span>Review of PCBs in US schools: a brief history, an estimate of the number of impacted schools, and an approach for evaluating indoor <span class="hlt">air</span> <span class="hlt">samples</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Herrick, Robert F; Stewart, James H; Allen, Joseph G</p> <p>2016-02-01</p> <p>PCBs in building materials such as caulks and sealants are a largely unrecognized source of contamination in the building environment. Schools are of particular interest, as the period of extensive school construction (about 1950 to 1980) coincides with the time of greatest use of PCBs as plasticizers in building materials. In the USA, we estimate that the number of schools with PCB in building caulk ranges from 12,960 to 25,920 based upon the number of schools built in the time of PCB use and the proportion of buildings found to contain PCB caulk and sealants. Field and laboratory studies have demonstrated that PCBs from both interior and exterior caulking can be the source of elevated PCB <span class="hlt">air</span> concentrations in these buildings, at levels that exceed health-based PCB exposure guidelines for building occupants. <span class="hlt">Air</span> <span class="hlt">sampling</span> in buildings containing PCB caulk has shown that the airborne PCB concentrations can be highly variable, even in repeat <span class="hlt">samples</span> collected within a room. <span class="hlt">Sampling</span> and data analysis strategies that recognize this variability can provide the basis for informed decision making about compliance with health-based exposure limits, even in cases where small numbers of <span class="hlt">samples</span> are taken. The health risks posed by PCB exposures, particularly among children, mandate precautionary approaches to managing PCBs in building materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27825846','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27825846"><span>PAHs and PCBs in an Eastern Mediterranean megacity, Istanbul: Their spatial and temporal distributions, <span class="hlt">air</span>-soil exchange and toxicological effects.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cetin, Banu; Ozturk, Fatma; Keles, Melek; Yurdakul, Sema</p> <p>2017-01-01</p> <p>Istanbul, one of the mega cities in the world located between Asia and Europe, has suffered from severe <span class="hlt">air</span> pollution problems due to rapid population growth, traffic and industry. Atmospheric levels of PAHs and PCBs were investigated in Istanbul at 22 <span class="hlt">sampling</span> sites during four different <span class="hlt">sampling</span> periods using PUF disk passive <span class="hlt">air</span> samplers and spatial and temporal variations of these chemicals were determined. Soil <span class="hlt">samples</span> were also taken at the <span class="hlt">air</span> <span class="hlt">sampling</span> sites. At all sites, the average ambient <span class="hlt">air</span> Σ 15 PAH and Σ 41 PCB concentrations were found as 85.6 ± 68.3 ng m -3 and 246 ± 122 pg m -3 , respectively. Phenanthrene and anthracene were the predominant PAHs and low molecular weight congeners dominated the PCBs. The PAH concentrations were higher especially at urban sites close to highways. However, the PCBs showed moderately uniform spatial variations. Except four sites, the PAH concentrations were increased with decreasing temperatures during the <span class="hlt">sampling</span> period, indicating the contributions of combustion sources for residential heating, while PCB concentrations were mostly increased with the temperature, probably due to enhanced volatilization at higher temperatures from their sources. The results of the Factor Analysis represented the impact of traffic, petroleum, coal/biomass and natural gas combustion and medical waste incineration plants on ambient <span class="hlt">air</span> concentrations. A similar spatial distribution trend was observed in the soil <span class="hlt">samples</span>. Fugacity ratio results indicated that the source/sink tendency of soil for PAHs and PCBs depends on their volatility and temperature; soil generally acts as a source for lighter PAHs and PCBs particularly in higher temperatures while atmospheric deposition is a main source for higher molecular weight compounds in local soils. Toxicological effect studies also <span class="hlt">revealed</span> the severity of <span class="hlt">air</span> and soil pollution especially in terms of PAHs in Istanbul. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5507793','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5507793"><span>Rectal perforation by compressed <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2017-01-01</p> <p>As the use of compressed <span class="hlt">air</span> in industrial work has increased, so has the risk of associated pneumatic injury from its improper use. However, damage of large intestine caused by compressed <span class="hlt">air</span> is uncommon. Herein a case of pneumatic rupture of the rectum is described. The patient was admitted to the Emergency Room complaining of abdominal pain and distension. His colleague triggered a compressed <span class="hlt">air</span> nozzle over his buttock. On arrival, vital signs were stable but physical examination <span class="hlt">revealed</span> peritoneal irritation and marked distension of the abdomen. Computed tomography showed a large volume of <span class="hlt">air</span> in the peritoneal cavity and subcutaneous emphysema at the perineum. A rectal perforation was found at laparotomy and the Hartmann procedure was performed. PMID:28706893</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/443381-effect-ozone-generating-air-purifying-device-reducing-concentrations-formaldehyde-air','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/443381-effect-ozone-generating-air-purifying-device-reducing-concentrations-formaldehyde-air"><span>Effect of an ozone-generating <span class="hlt">air</span>-purifying device on reducing concentrations of formaldehyde in <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Esswein, E.J.; Boeniger, M.F.</p> <p>1994-02-01</p> <p>Formaldehyde, an <span class="hlt">air</span> contaminant found in many indoor <span class="hlt">air</span> investigations, poses distinct occupational exposure hazards in certain job categories (e.g., mortuary science) but is also of concern when found or suspected in office buildings and homes. A variety of <span class="hlt">air</span>-purifying devices (APDs) are currently available or marketed for application to reduce or remove concentrations of a variety of indoor <span class="hlt">air</span> pollutants through the use of ozone as a chemical oxidant. An investigation was conducted to determine if concentrations of formaldehyde similar to those found in industrial hygiene evaluations of funeral homes could be reduced with the use of an ozone-generatingmore » APD. An ozone-generating APD was placed in an exposure chamber and formaldehyde-containing embalming solution was allowed to evaporate naturally, creating peak and mean chamber concentrations of 2.5 and 1.3 ppm, respectively. Continuous-reading instruments were used to <span class="hlt">sample</span> for formaldehyde and ozone. Active <span class="hlt">sampling</span> methods were also used to <span class="hlt">sample</span> simultaneously for formaldehyde and a possible reactant product, formic acid. Triplicate measurements were made in each of three evaluations: formaldehyde alone, ozone alone, and formaldehyde and ozone combined. Concentrations of formaldehyde were virtually identical with and without 0.5 ppm ozone. No reduction in formaldehyde concentration was found during a 90-minute evaluation using ozone at this concentration with peak and average concentrations of approximately 2.5 and 1.3 ppm formaldehyde, respectively. The results of this investigation suggest that the use of ozone is ineffective in reducing concentrations of formaldehyde. Because ozone has demonstrated health hazards, and is a regulated <span class="hlt">air</span> contaminant in both the occupational and ambient environment, the use of ozone as an <span class="hlt">air</span> purification agent in indoor <span class="hlt">air</span> does not seem warranted. 25 refs., 5 figs., 4 tabs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol4/pdf/CFR-2010-title40-vol4-sec52-2682.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol4/pdf/CFR-2010-title40-vol4-sec52-2682.pdf"><span>40 CFR 52.2682 - <span class="hlt">Air</span> quality surveillance.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 40 Protection of Environment 4 2010-07-01 2010-07-01 false <span class="hlt">Air</span> quality surveillance. 52.2682... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Guam § 52.2682 <span class="hlt">Air</span> quality... Pollution Control Standards and Regulations” (buffer zones—<span class="hlt">air</span> quality <span class="hlt">sampling</span>) are not in conformance with...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol5/pdf/CFR-2012-title40-vol5-sec52-2682.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol5/pdf/CFR-2012-title40-vol5-sec52-2682.pdf"><span>40 CFR 52.2682 - <span class="hlt">Air</span> quality surveillance.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... 40 Protection of Environment 5 2012-07-01 2012-07-01 false <span class="hlt">Air</span> quality surveillance. 52.2682... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Guam § 52.2682 <span class="hlt">Air</span> quality... Pollution Control Standards and Regulations” (buffer zones—<span class="hlt">air</span> quality <span class="hlt">sampling</span>) are not in conformance with...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol5/pdf/CFR-2013-title40-vol5-sec52-2682.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol5/pdf/CFR-2013-title40-vol5-sec52-2682.pdf"><span>40 CFR 52.2682 - <span class="hlt">Air</span> quality surveillance.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... 40 Protection of Environment 5 2013-07-01 2013-07-01 false <span class="hlt">Air</span> quality surveillance. 52.2682... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Guam § 52.2682 <span class="hlt">Air</span> quality... Pollution Control Standards and Regulations” (buffer zones—<span class="hlt">air</span> quality <span class="hlt">sampling</span>) are not in conformance with...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol5/pdf/CFR-2014-title40-vol5-sec52-2682.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol5/pdf/CFR-2014-title40-vol5-sec52-2682.pdf"><span>40 CFR 52.2682 - <span class="hlt">Air</span> quality surveillance.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... 40 Protection of Environment 5 2014-07-01 2014-07-01 false <span class="hlt">Air</span> quality surveillance. 52.2682... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Guam § 52.2682 <span class="hlt">Air</span> quality... Pollution Control Standards and Regulations” (buffer zones—<span class="hlt">air</span> quality <span class="hlt">sampling</span>) are not in conformance with...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol4/pdf/CFR-2011-title40-vol4-sec52-2682.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol4/pdf/CFR-2011-title40-vol4-sec52-2682.pdf"><span>40 CFR 52.2682 - <span class="hlt">Air</span> quality surveillance.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 40 Protection of Environment 4 2011-07-01 2011-07-01 false <span class="hlt">Air</span> quality surveillance. 52.2682... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Guam § 52.2682 <span class="hlt">Air</span> quality... Pollution Control Standards and Regulations” (buffer zones—<span class="hlt">air</span> quality <span class="hlt">sampling</span>) are not in conformance with...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11746880','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11746880"><span>Extraction of CO2 from <span class="hlt">air</span> <span class="hlt">samples</span> for isotopic analysis and limits to ultra high precision delta18O determination in CO2 gas.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Werner, R A; Rothe, M; Brand, W A</p> <p>2001-01-01</p> <p>The determination of delta18O values in CO2 at a precision level of +/-0.02 per thousand (delta-notation) has always been a challenging, if not impossible, analytical task. Here, we demonstrate that beyond the usually assumed major cause of uncertainty - water contamination - there are other, hitherto underestimated sources of contamination and processes which can alter the oxygen isotope composition of CO2. Active surfaces in the preparation line with which CO2 comes into contact, as well as traces of <span class="hlt">air</span> in the <span class="hlt">sample</span>, can alter the apparent delta18O value both temporarily and permanently. We investigated the effects of different surface materials including electropolished stainless steel, Duran glass, gold and quartz, the latter both untreated and silanized. CO2 frozen with liquid nitrogen showed a transient alteration of the 18O/16O ratio on all surfaces tested. The time to recover from the alteration as well as the size of the alteration varied with surface type. Quartz that had been ultrasonically cleaned for several hours with high purity water (0.05 microS) exhibited the smallest effect on the measured oxygen isotopic composition of CO2 before and after freezing. However, quartz proved to be mechanically unstable with time when subjected to repeated large temperature changes during operation. After several days of operation the gas released from the freezing step contained progressively increasing trace amounts of O2 probably originating from inclusions within the quartz, which precludes the use of quartz for cryogenically trapping CO2. Stainless steel or gold proved to be suitable materials after proper pre-treatment. To ensure a high trapping efficiency of CO2 from a flow of gas, a cold trap design was chosen comprising a thin wall 1/4" outer tube and a 1/8" inner tube, made respectively from electropolished stainless steel and gold. Due to a considerable 18O specific isotope effect during the release of CO2 from the cold surface, the thawing time had to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhDT........44P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhDT........44P"><span>Automated <span class="hlt">air</span>-void system characterization of hardened concrete: Helping computers to count <span class="hlt">air</span>-voids like people count <span class="hlt">air</span>-voids---Methods for flatbed scanner calibration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peterson, Karl</p> <p></p> <p>Since the discovery in the late 1930s that <span class="hlt">air</span> entrainment can improve the durability of concrete, it has been important for people to know the quantity, spacial distribution, and size distribution of the <span class="hlt">air</span>-voids in their concrete mixes in order to ensure a durable final product. The task of <span class="hlt">air</span>-void system characterization has fallen on the microscopist, who, according to a standard test method laid forth by the American Society of Testing and Materials, must meticulously count or measure about a thousand <span class="hlt">air</span>-voids per <span class="hlt">sample</span> as exposed on a cut and polished cross-section of concrete. The equipment used to perform this task has traditionally included a stereomicroscope, a mechanical stage, and a tally counter. Over the past 30 years, with the availability of computers and digital imaging, automated methods have been introduced to perform the same task, but using the same basic equipment. The method described here replaces the microscope and mechanical stage with an ordinary flatbed desktop scanner, and replaces the microscopist and tally counter with a personal computer; two pieces of equipment much more readily available than a microscope with a mechanical stage, and certainly easier to find than a person willing to sit for extended periods of time counting <span class="hlt">air</span>-voids. Most laboratories that perform <span class="hlt">air</span>-void system characterization typically have cabinets full of prepared <span class="hlt">samples</span> with corresponding results from manual operators. Proponents of automated methods often take advantage of this fact by analyzing the same <span class="hlt">samples</span> and comparing the results. A similar iterative approach is described here where scanned images collected from a significant number of <span class="hlt">samples</span> are analyzed, the results compared to those of the manual operator, and the settings optimized to best approximate the results of the manual operator. The results of this calibration procedure are compared to an alternative calibration procedure based on the more rigorous digital image accuracy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=California+AND+pollution&pg=3&id=ED072927','ERIC'); return false;" href="https://eric.ed.gov/?q=California+AND+pollution&pg=3&id=ED072927"><span>Correction of Anisokinetic <span class="hlt">Sampling</span> Errors.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Nelson, William G.</p> <p></p> <p>Gas flow patterns at a <span class="hlt">sampling</span> nozzle are described in this presentation for the 12th Conference on Methods in <span class="hlt">Air</span> Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971. Three situations for <span class="hlt">sampling</span> velocity are illustrated and analyzed, where the flow upstream of a <span class="hlt">sampling</span> probe is: (1) equal to free stream…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21462068','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21462068"><span>Potential artifacts associated with historical preparation of joint compound <span class="hlt">samples</span> and reported airborne asbestos concentrations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brorby, G P; Sheehan, P J; Berman, D W; Bogen, K T; Holm, S E</p> <p>2011-05-01</p> <p>Airborne <span class="hlt">samples</span> collected in the 1970s for drywall workers using asbestos-containing joint compounds were likely prepared and analyzed according to National Institute of Occupational Safety and Health Method P&CAM 239, the historical precursor to current Method 7400. Experimentation with a re-created, chrysotile-containing, carbonate-based joint compound suggested that analysis following <span class="hlt">sample</span> preparation by the historical vs. current method produces different fiber counts, likely because of an interaction between the different clearing and mounting chemicals used and the carbonate-based joint compound matrix. Differences were also observed during analysis using Method 7402, depending on whether acetic acid/dimethylformamide or acetone was used during preparation to collapse the filter. Specifically, <span class="hlt">air</span> <span class="hlt">samples</span> of sanded chrysotile-containing joint compound prepared by the historical method yielded fiber counts significantly greater (average of 1.7-fold, 95% confidence interval: 1.5- to 2.0-fold) than those obtained by the current method. In addition, <span class="hlt">air</span> <span class="hlt">samples</span> prepared by Method 7402 using acetic acid/dimethylformamide yielded fiber counts that were greater (2.8-fold, 95% confidence interval: 2.5- to 3.2-fold) than those prepared by this method using acetone. These results indicated (1) there is an interaction between Method P&CAM 239 preparation chemicals and the carbonate-based joint compound matrix that <span class="hlt">reveals</span> fibers that were previously bound in the matrix, and (2) the same appeared to be true for Method 7402 preparation chemicals acetic acid/dimethylformamide. This difference in fiber counts is the opposite of what has been reported historically for <span class="hlt">samples</span> of relatively pure chrysotile dusts prepared using the same chemicals. This preparation artifact should be considered when interpreting historical <span class="hlt">air</span> <span class="hlt">samples</span> for drywall workers prepared by Method P&CAM 239. Copyright © 2011 JOEH, LLC</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11540967','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11540967"><span>The interaction of culture with general job stressors in <span class="hlt">air</span> traffic controllers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shouksmith, G; Taylor, J E</p> <p>1997-01-01</p> <p>Elements of the job of <span class="hlt">Air</span> Traffic Controllers perceived as being stressful were rated for degree of stressfulness by a group of Singaporean controllers. The results were compared with those from earlier studies in Canada and New Zealand. It was hypothesized that the international nature of the job would be reflected in findings from all three groups of controllers. It was further hypothesized, however, that environmental and cultural factors would produce differences among the groups and that these would be greater between the Asian and the two "Western" cultures than between the two earlier <span class="hlt">samples</span> studied. Results showed that the two Western cultures share 56% common variance in their perceptions of stressfulness, but this changes to 35% between the New Zealand and Singapore groups and only 21% between Canada and Singapore. Although comparison of the factor structure of the stress ratings of the Singapore and New Zealand <span class="hlt">samples</span> again confirmed a general pattern of underlying stressors related to <span class="hlt">air</span> traffic control (which fits general occupational models of stress), it also <span class="hlt">revealed</span> culturally specific components. The nature of these suggests that they are emhedded in the context of Asian environments and cultures. The conclusion is that stress in <span class="hlt">Air</span> Traffic Controllers is related both to generic occupation stressors and to others that are both organizationally and culturally specific.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22462441','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22462441"><span>Microbial <span class="hlt">air</span> contamination in indoor environment of a university library.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kalwasińska, Agnieszka; Burkowska, Aleksandra; Wilk, Iwona</p> <p>2012-01-01</p> <p>The present study was aimed at evaluating the number of bacteria and mould fungi in the indoor and outdoor environment of Toruń University Library. The <span class="hlt">sampling</span> sites were located in the rooms serving the functions typical of libraries (i.e. in the Main Reading Room, Current Periodicals Reading Room, Collections Conservation Laboratory, Old Prints Storeroom, in rooms serving other (non-library) functions (i.e. main hall, cafeteria, and toilet) as well as outside the library building. The analyses <span class="hlt">reveal</span> that the concentrations of bacterial as well as fungal aerosols estimated with the use of the impaction method ranged between 10(1)-10(3) CFU·m(-3), which corresponds to the concentrations normally observed in areas of this kind. Evaluation of the hygienic condition of the studied areas was based on the criteria for microbiological cleanliness in interiors submitted by the European Commission in 1993. According to this classification, the <span class="hlt">air</span> was considered to be heavily or moderately contaminated with bacteria, while the <span class="hlt">air</span> contamination with mould fungi was described as low or moderate. The <span class="hlt">air</span> in the Old Prints Storeroom was considered the least contaminated with microbial aerosol.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28453248','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28453248"><span>Heterocyclic Aromatics in Petroleum Coke, Snow, Lake Sediments, and <span class="hlt">Air</span> <span class="hlt">Samples</span> from the Athabasca Oil Sands Region.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Manzano, Carlos A; Marvin, Chris; Muir, Derek; Harner, Tom; Martin, Jonathan; Zhang, Yifeng</p> <p>2017-05-16</p> <p>The aromatic fractions of snow, lake sediment, and <span class="hlt">air</span> <span class="hlt">samples</span> collected during 2011-2014 in the Athabasca oil sands region were analyzed using two-dimensional gas chromatography following a nontargeted approach. Commonly monitored aromatics (parent and alkylated-polycyclic aromatic hydrocarbons and dibenzothiophenes) were excluded from the analysis, focusing mainly on other heterocyclic aromatics. The unknowns detected were classified into isomeric groups and tentatively identified using mass spectral libraries. Relative concentrations of heterocyclic aromatics were estimated and were found to decrease with distance from a reference site near the center of the developments and with increasing depth of sediments. The same heterocyclic aromatics identified in snow, lake sediments, and <span class="hlt">air</span> were observed in extracts of delayed petroleum coke, with similar distributions. This suggests that petroleum coke particles are a potential source of heterocyclic aromatics to the local environment, but other oil sands sources must also be considered. Although the signals of these heterocyclic aromatics diminished with distance, some were detected at large distances (>100 km) in snow and surface lake sediments, suggesting that the impact of industry can extend >50 km. The list of heterocyclic aromatics and the mass spectral library generated in this study can be used for future source apportionment studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=22809&Lab=NERL&keyword=guns&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=22809&Lab=NERL&keyword=guns&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--METALS IN <span class="hlt">AIR</span> ANALYTICAL RESULTS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The Metals in <span class="hlt">Air</span> data set contains analytical results for measurements of up to 11 metals in 344 <span class="hlt">air</span> <span class="hlt">samples</span> over 86 households. <span class="hlt">Samples</span> were taken by pumping standardized <span class="hlt">air</span> volumes through filters at indoor and outdoor sites around each household being <span class="hlt">sampled</span>. The primary ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17274311','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17274311"><span>Health and efficiency in trimix versus <span class="hlt">air</span> breathing in compressed <span class="hlt">air</span> workers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Van Rees Vellinga, T P; Verhoeven, A C; Van Dijk, F J H; Sterk, W</p> <p>2006-01-01</p> <p>The Western Scheldt Tunneling Project in the Netherlands provided a unique opportunity to evaluate the effects of trimix usage on the health of compressed <span class="hlt">air</span> workers and the efficiency of the project. Data analysis addressed 318 exposures to compressed <span class="hlt">air</span> at 3.9-4.4 bar gauge and 52 exposures to trimix (25% oxygen, 25% helium, and 50% nitrogen) at 4.6-4.8 bar gauge. Results <span class="hlt">revealed</span> three incidents of decompression sickness all of which involved the use of compressed <span class="hlt">air</span>. During exposure to compressed <span class="hlt">air</span>, the effects of nitrogen narcosis were manifested in operational errors and increased fatigue among the workers. When using trimix, less effort was required for breathing, and mandatory decompression times for stays of a specific duration and maximum depth were considerably shorter. We conclude that it might be rational--for both medical and operational reasons--to use breathing gases with lower nitrogen fractions (e.g., trimix) for deep-caisson work at pressures exceeding 3 bar gauge, although definitive studies are needed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29580079','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29580079"><span>Metagenomic analysis of bat guano <span class="hlt">samples</span> <span class="hlt">revealed</span> the presence of viruses potentially carried by insects, among others by Apis mellifera in Hungary.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zana, Brigitta; Kemenesi, Gábor; Urbán, Péter; Földes, Fanni; Görföl, Tamás; Estók, Péter; Boldogh, Sándor; Kurucz, Kornélia; Jakab, Ferenc</p> <p>2018-03-01</p> <p>The predominance of dietary viruses in bat guano <span class="hlt">samples</span> had been described recently, suggesting a new opportunity to survey the prevalence and to detect new viruses of arthropods or even plant-infecting viruses circulating locally in the ecosystem. Here we describe the diversity of viruses belonging to the order Picornavirales in Hungarian insectivorous bat guano <span class="hlt">samples</span>. The metagenomic analysis conducted on our <span class="hlt">samples</span> has <span class="hlt">revealed</span> the significant predominance of aphid lethal paralysis virus (ALPV) and Big Sioux River virus (BSRV) in Hungary for the first time. Phylogenetic analysis was used to clarify the relationship to previously identified ALPV strains infecting honey bees, showing that our strain possesses a close genetic relationship with the strains that have already been described as pathogenic to honey bees. Furthermore, studies have previously confirmed the ability of these viruses to replicate in adult honey bees; however, no signs related to these viruses have been <span class="hlt">revealed</span> yet. With the identification of two recently described possibly honey bee infecting viruses for the first time in Hungary, our results might have importance for the health conditions of Hungarian honey bee colonies in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29307752','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29307752"><span>A 2-year comparative study of mold and bacterial counts in <span class="hlt">air</span> <span class="hlt">samples</span> from neutral and positive pressure rooms in 2 tertiary care hospitals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ryan, Laura; O'Mara, Niall; Tansey, Sana; Slattery, Tom; Hanahoe, Belinda; Vellinga, Akke; Doyle, Maeve; Cormican, Martin</p> <p>2018-05-01</p> <p>Immunocompromised patients are at risk of invasive fungal infection. These high-risk patients are nursed in protective isolation to reduce the risk of nosocomial aspergillosis while in hospital-ideally in a positive pressure single room with high-efficiency particulate <span class="hlt">air</span> filtration. However, neutral pressure rooms are a potential alternative, especially for patients requiring both protective and source isolation. This study examined mold and bacterial concentrations in <span class="hlt">air</span> <span class="hlt">samples</span> from positive and neutral pressure rooms to assess whether neutral pressure rooms offer a similar environment to that of positive pressure rooms in terms of mold concentrations in the <span class="hlt">air</span>. Mold concentrations were found to be similar in the positive and neutral pressure room types examined in this study. These results add to the paucity of literature in this area. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4021317','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4021317"><span>Saturation <span class="hlt">sampling</span> for spatial variation in multiple <span class="hlt">air</span> pollutants across an inversion-prone metropolitan area of complex terrain</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>Background Characterizing intra-urban variation in <span class="hlt">air</span> quality is important for epidemiological investigation of health outcomes and disparities. To date, however, few studies have been designed to capture spatial variation during select hours of the day, or to examine the roles of meteorology and complex terrain in shaping intra-urban exposure gradients. Methods We designed a spatial saturation monitoring study to target local <span class="hlt">air</span> pollution sources, and to understand the role of topography and temperature inversions on fine-scale pollution variation by systematically allocating <span class="hlt">sampling</span> locations across gradients in key local emissions sources (vehicle traffic, industrial facilities) and topography (elevation) in the Pittsburgh area. Street-level integrated <span class="hlt">samples</span> of fine particulate matter (PM2.5), black carbon (BC), nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3) were collected during morning rush and probable inversion hours (6-11 AM), during summer and winter. We hypothesized that pollution concentrations would be: 1) higher under inversion conditions, 2) exacerbated in lower-elevation areas, and 3) vary by season. Results During July - August 2011 and January - March 2012, we observed wide spatial and seasonal variability in pollution concentrations, exceeding the range measured at regulatory monitors. We identified elevated concentrations of multiple pollutants at lower-elevation sites, and a positive association between inversion frequency and NO2 concentration. We examined temporal adjustment methods for deriving seasonal concentration estimates, and found that the appropriate reference temporal trend differs between pollutants. Conclusions Our time-stratified spatial saturation approach found some evidence for modification of inversion-concentration relationships by topography, and provided useful insights for refining and interpreting GIS-based pollution source indicators for Land Use Regression modeling. PMID:24735818</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24735818','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24735818"><span>Saturation <span class="hlt">sampling</span> for spatial variation in multiple <span class="hlt">air</span> pollutants across an inversion-prone metropolitan area of complex terrain.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shmool, Jessie Lc; Michanowicz, Drew R; Cambal, Leah; Tunno, Brett; Howell, Jeffery; Gillooly, Sara; Roper, Courtney; Tripathy, Sheila; Chubb, Lauren G; Eisl, Holger M; Gorczynski, John E; Holguin, Fernando E; Shields, Kyra Naumoff; Clougherty, Jane E</p> <p>2014-04-16</p> <p>Characterizing intra-urban variation in <span class="hlt">air</span> quality is important for epidemiological investigation of health outcomes and disparities. To date, however, few studies have been designed to capture spatial variation during select hours of the day, or to examine the roles of meteorology and complex terrain in shaping intra-urban exposure gradients. We designed a spatial saturation monitoring study to target local <span class="hlt">air</span> pollution sources, and to understand the role of topography and temperature inversions on fine-scale pollution variation by systematically allocating <span class="hlt">sampling</span> locations across gradients in key local emissions sources (vehicle traffic, industrial facilities) and topography (elevation) in the Pittsburgh area. Street-level integrated <span class="hlt">samples</span> of fine particulate matter (PM2.5), black carbon (BC), nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3) were collected during morning rush and probable inversion hours (6-11 AM), during summer and winter. We hypothesized that pollution concentrations would be: 1) higher under inversion conditions, 2) exacerbated in lower-elevation areas, and 3) vary by season. During July - August 2011 and January - March 2012, we observed wide spatial and seasonal variability in pollution concentrations, exceeding the range measured at regulatory monitors. We identified elevated concentrations of multiple pollutants at lower-elevation sites, and a positive association between inversion frequency and NO2 concentration. We examined temporal adjustment methods for deriving seasonal concentration estimates, and found that the appropriate reference temporal trend differs between pollutants. Our time-stratified spatial saturation approach found some evidence for modification of inversion-concentration relationships by topography, and provided useful insights for refining and interpreting GIS-based pollution source indicators for Land Use Regression modeling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008APS..DFD.GA002C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008APS..DFD.GA002C"><span><span class="hlt">Air</span> Layer Drag Reduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ceccio, Steven; Elbing, Brian; Winkel, Eric; Dowling, David; Perlin, Marc</p> <p>2008-11-01</p> <p>A set of experiments have been conducted at the US Navy's Large Cavitation Channel to investigate skin-friction drag reduction with the injection of <span class="hlt">air</span> into a high Reynolds number turbulent boundary layer. Testing was performed on a 12.9 m long flat-plate test model with the surface hydraulically smooth and fully rough at downstream-distance-based Reynolds numbers to 220 million and at speeds to 20 m/s. Local skin-friction, near-wall bulk void fraction, and near-wall bubble imaging were monitored along the length of the model. The instrument suite was used to access the requirements necessary to achieve <span class="hlt">air</span> layer drag reduction (ALDR). Injection of <span class="hlt">air</span> over a wide range of <span class="hlt">air</span> fluxes showed that three drag reduction regimes exist when injecting <span class="hlt">air</span>; (1) bubble drag reduction that has poor downstream persistence, (2) a transitional regime with a steep rise in drag reduction, and (3) ALDR regime where the drag reduction plateaus at 90% ± 10% over the entire model length with large void fractions in the near-wall region. These investigations <span class="hlt">revealed</span> several requirements for ALDR including; sufficient volumetric <span class="hlt">air</span> fluxes that increase approximately with the square of the free-stream speed, slightly higher <span class="hlt">air</span> fluxes are needed when the surface tension is reduced, higher <span class="hlt">air</span> fluxes are required for rough surfaces, and the formation of ALDR is sensitive to the inlet condition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=air+AND+quality&pg=4&id=EJ647221','ERIC'); return false;" href="https://eric.ed.gov/?q=air+AND+quality&pg=4&id=EJ647221"><span>EPA Pushing Improved <span class="hlt">Air</span> Quality in Schools.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Sack, Joetta L.</p> <p>2002-01-01</p> <p>Discusses how, in response to the growing problem of poor <span class="hlt">air</span> quality in schools, the Environmental Protection Agency (EPA) has set new voluntary <span class="hlt">air</span>-quality guidelines for schools. Addresses common <span class="hlt">air</span>-related irritants; successful efforts at Guerrero Elementary School in Mesa, Arizona; preventive maintenance; and a <span class="hlt">sample</span> of the EPA's…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21968260','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21968260"><span>Molecular comparison of the <span class="hlt">sampling</span> efficiency of four types of airborne bacterial samplers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Kejun</p> <p>2011-11-15</p> <p>In the present study, indoor and outdoor <span class="hlt">air</span> <span class="hlt">samples</span> were collected using four types of <span class="hlt">air</span> samplers often used for airborne bacterial <span class="hlt">sampling</span>. These <span class="hlt">air</span> samplers included two solid impactors (BioStage and RCS), one liquid impinger (BioSampler), and one filter sampler with two kinds of filters (a gelatin and a cellulose acetate filter). The collected <span class="hlt">air</span> <span class="hlt">samples</span> were further processed to analyze the diversity and abundance of culturable bacteria and total bacteria through standard culture techniques, denaturing gradient gel electrophoresis (DGGE) fingerprinting and quantitative polymerase chain reaction (qPCR) analysis. The DGGE analysis indicated that the <span class="hlt">air</span> <span class="hlt">samples</span> collected using the BioStage and RCS samplers have higher culturable bacterial diversity, whereas the <span class="hlt">samples</span> collected using the BioSampler and the cellulose acetate filter sampler have higher total bacterial diversity. To obtain more information on the <span class="hlt">sampled</span> bacteria, some gel bands were excised and sequenced. In terms of <span class="hlt">sampling</span> efficiency, results from the qPCR tests indicated that the collected total bacterial concentration was higher in <span class="hlt">samples</span> collected using the BioSampler and the cellulose acetate filter sampler. In conclusion, the <span class="hlt">sampling</span> bias and efficiency of four kinds of <span class="hlt">air</span> <span class="hlt">sampling</span> systems were compared in the present study and the two solid impactors were concluded to be comparatively efficient for culturable bacterial <span class="hlt">sampling</span>, whereas the liquid impactor and the cellulose acetate filter sampler were efficient for total bacterial <span class="hlt">sampling</span>. Copyright © 2011 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17706251','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17706251"><span><span class="hlt">Air</span>--sea gaseous exchange of PCB at the Venice lagoon (Italy).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Manodori, L; Gambaro, A; Moret, I; Capodaglio, G; Cescon, P</p> <p>2007-10-01</p> <p>Water bodies are important storage media for persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) and this function is increased in coastal regions because their inputs are higher than those to the open sea. The <span class="hlt">air</span>-water interface is extensively involved with the global cycling of PCBs because it is the place where they accumulate due to depositional processes and where they may be emitted by gaseous exchange. In this work the parallel collection of <span class="hlt">air</span>, microlayer and sub-superficial water <span class="hlt">samples</span> was performed in July 2005 at a site in the Venice lagoon to evaluate the summer gaseous flux of PCBs. The total concentration of PCBs (sum of 118 congeners) in <span class="hlt">air</span> varies from 87 to 273 pg m(-3), whereas in the operationally defined dissolved phase of microlayer and sub-superficial water <span class="hlt">samples</span> it varies from 159 to 391 pg L(-1). No significant enrichment of dissolved PCB into the microlayer has been observed, although a preferential accumulation of most hydrophobic congeners occurs. Due to this behaviour, we believe that the modified two-layer model was the most suitable approach for the evaluation of the flux at the <span class="hlt">air</span>-sea interface, because it takes into account the influence of the microlayer. From its application it appears that PCB volatilize from the lagoon waters with a net flux varying from 58 to 195 ng m(-2)d(-1) (uncertainty: +/-50-64%) due to the strong influence of wind speed. This flux is greater than those reported in the literature for the atmospheric deposition and rivers input and <span class="hlt">reveals</span> that PCB are actively emitted from the Venice lagoon in summer months.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol23/pdf/CFR-2011-title40-vol23-sec141-803.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol23/pdf/CFR-2011-title40-vol23-sec141-803.pdf"><span>40 CFR 141.803 - Coliform <span class="hlt">sampling</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Coliform <span class="hlt">sampling</span>. 141.803 Section 141...) NATIONAL PRIMARY DRINKING WATER REGULATIONS Aircraft Drinking Water Rule § 141.803 Coliform <span class="hlt">sampling</span>. (a) Analytical methodology. <span class="hlt">Air</span> carriers must follow the <span class="hlt">sampling</span> and analysis requirements under this section...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol22/pdf/CFR-2010-title40-vol22-sec141-803.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol22/pdf/CFR-2010-title40-vol22-sec141-803.pdf"><span>40 CFR 141.803 - Coliform <span class="hlt">sampling</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Coliform <span class="hlt">sampling</span>. 141.803 Section 141...) NATIONAL PRIMARY DRINKING WATER REGULATIONS Aircraft Drinking Water Rule § 141.803 Coliform <span class="hlt">sampling</span>. (a) Analytical methodology. <span class="hlt">Air</span> carriers must follow the <span class="hlt">sampling</span> and analysis requirements under this section...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2306019','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2306019"><span>Mold contamination of automobile <span class="hlt">air</span> conditioner systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kumar, P; Lopez, M; Fan, W; Cambre, K; Elston, R C</p> <p>1990-02-01</p> <p>Eight cars belonging to patients who were found to have exacerbation of allergic rhinitis and bronchial asthma after turning on the <span class="hlt">air</span> conditioner in their cars were examined. Mold concentrations inside the passenger compartment with the a/c turned off and at different climate control settings were lower than concentrations in the outside <span class="hlt">air</span>. After turning on the <span class="hlt">air</span> conditioner to "Max", cultures obtained at various intervals <span class="hlt">revealed</span> that mold concentrations decreased significantly with time. Furthermore, placement of a filter at the portal of entry of outside <span class="hlt">air</span> significantly reduced the mold concentration in the passenger compartment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170001673','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170001673"><span>NASA's Aerosol <span class="hlt">Sampling</span> Experiment Summary</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meyer, Marit E.</p> <p>2016-01-01</p> <p>In a spacecraft cabin environment, the size range of indoor aerosols is much larger and they persist longer than on Earth because they are not removed by gravitational settling. A previous aerosol experiment in 1991 documented that over 90 of the mass concentration of particles in the NASA Space Shuttle <span class="hlt">air</span> were between 10 m and 100 m based on measurements with a multi-stage virtual impactor and a nephelometer (Liu et al. 1991). While the now-retired Space Shuttle had short duration missions (less than two weeks), the International Space Station (ISS) has been continually inhabited by astronauts for over a decade. High concentrations of inhalable particles on ISS are potentially responsible for crew complaints of respiratory and eye irritation and comments about 'dusty' <span class="hlt">air</span>. <span class="hlt">Air</span> filtration is the current control strategy for airborne particles on the ISS, and filtration modeling, performed for engineering and design validation of the <span class="hlt">air</span> revitalization system in ISS, predicted that PM requirements would be met. However, aerosol monitoring has never been performed on the ISS to verify PM levels. A flight experiment is in preparation which will provide data on particulate matter in ISS ambient <span class="hlt">air</span>. Particles will be collected with a thermophoretic sampler as well as with passive samplers which will extend the particle size range of <span class="hlt">sampling</span>. <span class="hlt">Samples</span> will be returned to Earth for chemical and microscopic analyses, providing the first aerosol data for ISS ambient <span class="hlt">air</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6165796-urban-air-toxics-monitoring-program','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6165796-urban-air-toxics-monitoring-program"><span>Urban-<span class="hlt">air</span>-toxics Monitoring Program, 1990</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Not Available</p> <p>1991-06-01</p> <p>From March 1990 through February 1991 <span class="hlt">samples</span> of ambient <span class="hlt">air</span> were collected at 12 sites in the eastern part of the U.S. Every 12 days, <span class="hlt">air</span> was integrated over 24-hour periods into passivated stainless steel canisters. Simultaneously, <span class="hlt">air</span> was drawn through cartridges containing dinitrophenylhydrazine to collect carbonyl compounds. The <span class="hlt">samples</span> were analyzed at a central laboratory for a total of 37 halogenated and aromatic hydrocarbons, formaldehyde, acetaldehyde, and other oxygenated species. The hydrocarbon species were analyzed by gas chromatography/multiple detectors and gas chromatography/mass spectrometry, while the carbonyl species were analyzed by liquid chromatography. Complete data for all the hydrocarbon samplesmore » are presented in the report.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5616079-environmental-sampling-analysis-support-nti','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5616079-environmental-sampling-analysis-support-nti"><span>Environmental <span class="hlt">sampling</span> and analysis in support of NTI-3</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>McGuire, R.R.; Harrar, J.E.; Haas, J.S.</p> <p>1991-04-06</p> <p>The third National Trail Inspection took place at the Monsanto Chemical Plant in Luling, Louisiana. In order to test the effectiveness of environmental <span class="hlt">sampling</span> (soil, water and <span class="hlt">air</span>) in determining the nature of the chemical process in a given production plant and to examine the distance from a process building that <span class="hlt">samples</span> can effectively be taken, we needed to select some materials that constituted components of process streams. Three materials were selected: 1. isopropyl amine for <span class="hlt">air</span> monitoring, 2. 4-nitrophenol, one of the precursors in the acetaminophen process, and 3. an intermediate in the production of glyphosate for ROUNDUP thatmore » is known simply as glyphosate intermediated. LLNL did not participate in the <span class="hlt">air</span> <span class="hlt">sampling</span> nor the analysis for isopropyl amine. This paper discussed the steps in this experiment including <span class="hlt">sample</span> collection, <span class="hlt">sample</span> workshop, <span class="hlt">sample</span> analysis the results and discussion and the conclusion. 3 figs., 6 tabs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title10-vol3/pdf/CFR-2014-title10-vol3-sec429-15.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title10-vol3/pdf/CFR-2014-title10-vol3-sec429-15.pdf"><span>10 CFR 429.15 - Room <span class="hlt">air</span> conditioners.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-01-01</p> <p>... 10 Energy 3 2014-01-01 2014-01-01 false Room <span class="hlt">air</span> conditioners. 429.15 Section 429.15 Energy... COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification § 429.15 Room <span class="hlt">air</span> conditioners. (a) <span class="hlt">Sampling</span> plan for selection of units for testing. (1) The requirements of § 429.11 are applicable to room <span class="hlt">air</span> conditioners...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title10-vol3/pdf/CFR-2013-title10-vol3-sec429-15.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title10-vol3/pdf/CFR-2013-title10-vol3-sec429-15.pdf"><span>10 CFR 429.15 - Room <span class="hlt">air</span> conditioners.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-01-01</p> <p>... 10 Energy 3 2013-01-01 2013-01-01 false Room <span class="hlt">air</span> conditioners. 429.15 Section 429.15 Energy... COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification § 429.15 Room <span class="hlt">air</span> conditioners. (a) <span class="hlt">Sampling</span> plan for selection of units for testing. (1) The requirements of § 429.11 are applicable to room <span class="hlt">air</span> conditioners...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/862450','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/862450"><span>Method and apparatus for <span class="hlt">sampling</span> atmospheric mercury</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Trujillo, Patricio E.; Campbell, Evan E.; Eutsler, Bernard C.</p> <p>1976-01-20</p> <p>A method of simultaneously <span class="hlt">sampling</span> particulate mercury, organic mercurial vapors, and metallic mercury vapor in the working and occupational environment and determining the amount of mercury derived from each such source in the <span class="hlt">sampled</span> <span class="hlt">air</span>. A known volume of <span class="hlt">air</span> is passed through a <span class="hlt">sampling</span> tube containing a filter for particulate mercury collection, a first adsorber for the selective adsorption of organic mercurial vapors, and a second adsorber for the adsorption of metallic mercury vapor. Carbon black molecular sieves are particularly useful as the selective adsorber for organic mercurial vapors. The amount of mercury adsorbed or collected in each section of the <span class="hlt">sampling</span> tube is readily quantitatively determined by flameless atomic absorption spectrophotometry.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26PSL.390..244B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26PSL.390..244B"><span>The origin of water in the primitive Moon as <span class="hlt">revealed</span> by the lunar highlands <span class="hlt">samples</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barnes, Jessica J.; Tartèse, Romain; Anand, Mahesh; McCubbin, Francis M.; Franchi, Ian A.; Starkey, Natalie A.; Russell, Sara S.</p> <p>2014-03-01</p> <p>The recent discoveries of hydrogen (H) bearing species on the lunar surface and in <span class="hlt">samples</span> derived from the lunar interior have necessitated a paradigm shift in our understanding of the water inventory of the Moon, which was previously considered to be a ‘bone-dry’ planetary body. Most <span class="hlt">sample</span>-based studies have focused on assessing the water contents of the younger mare basalts and pyroclastic glasses, which are partial-melting products of the lunar mantle. In contrast, little attention has been paid to the inventory and source(s) of water in the lunar highlands rocks which are some of the oldest and most pristine materials available for laboratory investigations, and that have the potential to <span class="hlt">reveal</span> the original history of water in the Earth-Moon system. Here, we report in-situ measurements of hydroxyl (OH) content and H isotopic composition of the mineral apatite from four lunar highlands <span class="hlt">samples</span> (two norites, a troctolite, and a granite clast) collected during the Apollo missions. Apart from troctolite in which the measured OH contents in apatite are close to our analytical detection limit and its H isotopic composition appears to be severely compromised by secondary processes, we have measured up to ˜2200 ppm OH in the granite clast with a weighted average δD of ˜ -105±130‰, and up to ˜3400 ppm OH in the two norites (77215 and 78235) with weighted average δD values of -281±49‰ and -27±98‰, respectively. The apatites in the granite clast and the norites are characterised by higher OH contents than have been reported so far for highlands <span class="hlt">samples</span>, and have H isotopic compositions similar to those of terrestrial materials and some carbonaceous chondrites, providing one of the strongest pieces of evidence yet for a common origin for water in the Earth-Moon system. In addition, the presence of water, of terrestrial affinity, in some <span class="hlt">samples</span> of the earliest-formed lunar crust suggests that either primordial terrestrial water survived the aftermath</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol8/pdf/CFR-2010-title40-vol8-sec61-44.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol8/pdf/CFR-2010-title40-vol8-sec61-44.pdf"><span>40 CFR 61.44 - Stack <span class="hlt">sampling</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Stack <span class="hlt">sampling</span>. 61.44 Section 61.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) <span class="hlt">AIR</span> PROGRAMS (CONTINUED) NATIONAL... Firing § 61.44 Stack <span class="hlt">sampling</span>. (a) Sources subject to § 61.42(b) shall be continuously <span class="hlt">sampled</span>, during...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol8/pdf/CFR-2011-title40-vol8-sec61-44.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol8/pdf/CFR-2011-title40-vol8-sec61-44.pdf"><span>40 CFR 61.44 - Stack <span class="hlt">sampling</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Stack <span class="hlt">sampling</span>. 61.44 Section 61.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) <span class="hlt">AIR</span> PROGRAMS (CONTINUED) NATIONAL... Firing § 61.44 Stack <span class="hlt">sampling</span>. (a) Sources subject to § 61.42(b) shall be continuously <span class="hlt">sampled</span>, during...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25509546','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25509546"><span>Characterization of indoor <span class="hlt">air</span> quality and resident health in an Arizona senior housing apartment building.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Frey, Sarah E; Destaillats, Hugo; Cohn, Sebastian; Ahrentzen, Sherry; Fraser, Matthew P</p> <p>2014-11-01</p> <p>A survey of key indoor <span class="hlt">air</span> quality (IAQ) parameters and resident health was carried out in 72 apartments within a single low-income senior housing building in Phoenix, Arizona. <span class="hlt">Air</span> <span class="hlt">sampling</span> was carried out simultaneously with a questionnaire on personal habits and general health of residents. Mean PM10 concentrations are 66 +/- 16, 58 +/- 13, and 24 +/- 3 microg/m3 and mean PM2.5 concentrations are 62 +/- 16, 53 +/- 13, and 20 +/- 2 microg/m3 for the living room, kitchen, and outdoor balcony, respectively. Median PM10 concentrations are 17, 18 and 17 microg/m3 and median PM25 concentrations are 13, 14, and 13 microg/m3, respectively. The initial results indicate that increased indoor particle concentrations coincide with residents who report smoking cigarettes. Indoor formaldehyde concentrations <span class="hlt">revealed</span> median levels of 36.9, 38.8, and 4.3 ppb in the living room, kitchen, and balcony, respectively. Results show that 36% of living room <span class="hlt">samples</span> and 44% of kitchen <span class="hlt">samples</span> exceeded the Health Canada REL for chronic exposure to formaldehyde (40 ppb). Associations between occupants' behavior self-reported health conditions, and IAQ are evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol23/pdf/CFR-2011-title40-vol23-sec141-802.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol23/pdf/CFR-2011-title40-vol23-sec141-802.pdf"><span>40 CFR 141.802 - Coliform <span class="hlt">sampling</span> plan.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Coliform <span class="hlt">sampling</span> plan. 141.802... <span class="hlt">sampling</span> plan. (a) Each <span class="hlt">air</span> carrier under this subpart must develop a coliform <span class="hlt">sampling</span> plan covering each... required actions, including repeat and follow-up <span class="hlt">sampling</span>, corrective action, and notification of...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol22/pdf/CFR-2010-title40-vol22-sec141-802.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol22/pdf/CFR-2010-title40-vol22-sec141-802.pdf"><span>40 CFR 141.802 - Coliform <span class="hlt">sampling</span> plan.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Coliform <span class="hlt">sampling</span> plan. 141.802... <span class="hlt">sampling</span> plan. (a) Each <span class="hlt">air</span> carrier under this subpart must develop a coliform <span class="hlt">sampling</span> plan covering each... required actions, including repeat and follow-up <span class="hlt">sampling</span>, corrective action, and notification of...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008ApSS..254.2472V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008ApSS..254.2472V"><span>Investigation on the effect of RF <span class="hlt">air</span> plasma and neem leaf extract treatment on the surface modification and antimicrobial activity of cotton fabric</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vaideki, K.; Jayakumar, S.; Rajendran, R.; Thilagavathi, G.</p> <p>2008-02-01</p> <p>A thorough investigation on the antimicrobial activity of RF <span class="hlt">air</span> plasma and azadirachtin (neem leaf extract) treated cotton fabric has been dealt with in this paper. The cotton fabric was given a RF <span class="hlt">air</span> plasma treatment to improve its hydrophilicity. The process parameters such as electrode gap, time of exposure and RF power have been varied to study their effect in improving the hydrophilicity of the cotton fabric and they were optimized based on the static immersion test results. The neem leaf extract (azadirachtin) was applied on fabric <span class="hlt">samples</span> to impart antimicrobial activity. The antimicrobial efficacy of the <span class="hlt">samples</span> have been analysed and compared with the efficacy of the cotton fabric treated with the antimicrobial finish alone. The investigation <span class="hlt">reveals</span> that the RF <span class="hlt">air</span> plasma has modified the surface of the fabric, which in turn increased the antimicrobial activity of the fabric when treated with azadirachtin. The surface modification due to RF <span class="hlt">air</span> plasma treatment has been analysed by comparing the FTIR spectra of the untreated and plasma treated <span class="hlt">samples</span>. The molecular interaction between the fabric, azadirachtin and citric acid which was used as a cross linking agent to increase the durability of the antimicrobial finish has also been analysed using FTIR spectra.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29253624','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29253624"><span>Traffic flow and microbial <span class="hlt">air</span> contamination in operating rooms at a major teaching hospital in Ghana.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stauning, M T; Bediako-Bowan, A; Andersen, L P; Opintan, J A; Labi, A-K; Kurtzhals, J A L; Bjerrum, S</p> <p>2018-07-01</p> <p>Current literature examining the relationship between door-opening rate, number of people present, and microbial <span class="hlt">air</span> contamination in the operating room is limited. Studies are especially needed from low- and middle-income countries, where the risk of surgical site infections is high. To assess microbial <span class="hlt">air</span> contamination in operating rooms at a Ghanaian teaching hospital and the association with door-openings and number of people present. Moreover, we aimed to document reasons for door-opening. We conducted active <span class="hlt">air-sampling</span> using an MAS 100 ® portable impactor during 124 clean or clean-contaminated elective surgical procedures. The number of people present, door-opening rate and the reasons for each door-opening were recorded by direct observation using pretested structured observation forms. During surgery, the mean number of colony-forming units (cfu) was 328 cfu/m 3 <span class="hlt">air</span>, and 429 (84%) of 510 <span class="hlt">samples</span> exceeded a recommended level of 180 cfu/m 3 . Of 6717 door-openings recorded, 77% were considered unnecessary. Levels of cfu/m 3 were strongly correlated with the number of people present (P = 0.001) and with the number of door-openings/h (P = 0.02). In empty operating rooms, the mean cfu count was 39 cfu/m 3 after 1 h of uninterrupted ventilation and 52 (51%) of 102 <span class="hlt">samples</span> exceeded a recommended level of 35 cfu/m 3 . The study <span class="hlt">revealed</span> high values of intraoperative airborne cfu exceeding recommended levels. Minimizing the number of door-openings and people present during surgery could be an effective strategy to reduce microbial <span class="hlt">air</span> contamination in low- and middle-income settings. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28959632','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28959632"><span>Diacetyl and 2,3-pentanedione in breathing zone and area <span class="hlt">air</span> during large-scale commercial coffee roasting, blending and grinding processes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McCoy, Michael J; Hoppe Parr, Kimberly A; Anderson, Kim E; Cornish, Jim; Haapala, Matti; Greivell, John</p> <p>2017-01-01</p> <p>Recently described scientific literature has identified the airborne presence of 2,3-butanedione (diacetyl) and 2,3-pentanedione at concentrations approaching or potentially exceeding the current American Conference of Industrial Hygienists' (ACGIH) Threshold Limit Values (TLVs) at commercial coffee roasting and production facilities. Newly established National Institutes of Occupational Safety and Health (NIOSH) Recommended Exposure Limits for diacetyl and 2,3-pentanedione are even more conservative. Chronic exposure to these alpha-diketones at elevated airborne concentrations has been associated with lung damage, specifically bronchiolitis obliterans, most notably in industrial food processing facilities. Workers at a large commercial coffee roaster were monitored for both eight-hour and task-based, short-term, 15-min <span class="hlt">sample</span> durations for airborne concentrations of these alpha-diketones during specific work processes, including the coffee bean roasting, blending and grinding processes, during two separate 8-h work periods. Additionally, the authors performed real-time Fourier transform infrared spectroscopy (FTIR) analysis of the workers' breathing zone as well as the area workplace <span class="hlt">air</span> for the presence of organic compounds to determine the sources, as well as quantitate and identify various organic compounds proximal to the roasting and grinding processes. Real-time FTIR measurements provided both the identification and quantitation of diacetyl and 2,3-pentanedione, as well as other organic compounds generated during coffee bean roasting and grinding operations. Airborne concentrations of diacetyl in the workers' breathing zone, as eight-hour time-weighted averages were less than the ACGIH TLVs for diacetyl, while concentrations of 2,3-pentanedione were below the limit of detection in all <span class="hlt">samples</span>. Short-term breathing zone <span class="hlt">samples</span> <span class="hlt">revealed</span> airborne concentrations for diacetyl that exceeded the ACGIH short-term exposure limit of 0.02 parts per million (ppm) in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100035098','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100035098"><span>Assessment of <span class="hlt">Air</span> Quality in the International Space Station (ISS) and Space Shuttle Based on <span class="hlt">Samples</span> Returned Aboard STS-110 (ISS-8A) in April 2002</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>James, John T.</p> <p>2002-01-01</p> <p>The toxicological assessment of grab <span class="hlt">sample</span> canisters (GSCs) returned aboard STS-110 is reported. Analytical methods have not changed from earlier reports, and surrogate standard recoveries from the GSCs were 77-121%, with one exception. Pressure tracking indicated no leaks in the canisters. Recoveries from lab and trip controls for formaldehyde analyses ranged from 87 to 96%. The two general criteria used to assess <span class="hlt">air</span> quality are the total-non-methane-volatile organic hydrocarbons (NMVOCs) and the total T-value (minus the CO2 and formaldehyde contributions). Because of the inertness of Freon 218 (octafluoropropane, OFP), its contribution to the NMVOC is subtracted and tabulated separately. Control of atmospheric alcohols is important to the water recovery system engineers, hence total alcohols are also shown for each <span class="hlt">sample</span>. Because formaldehyde is quantified from sorbent badges, its concentration is listed separately. These five indices of <span class="hlt">air</span> quality are summarized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=144311&Lab=NRMRL&keyword=Business+AND+Research+AND+Methods&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=144311&Lab=NRMRL&keyword=Business+AND+Research+AND+Methods&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>ASSESSMENT OF VAPOR INTRUSION USING INDOOR AND SUB-SLAB <span class="hlt">AIR</span> <span class="hlt">SAMPLING</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The objective of this investigation was to develop a method for evaluating vapor intrusion using indoor and sub-slab <span class="hlt">air</span> measurement and at the same time directly assist EPA’s New England Regional Office in evaluating vapor intrusion in 15 homes and one business near the former R...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=237911&keyword=diabetes+AND+1&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=237911&keyword=diabetes+AND+1&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span><span class="hlt">Air</span> Pollution and Health: Emerging Information on Susceptible Populations</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Outdoor <span class="hlt">air</span> pollution poses risks to human health in communities around the world, and research on populations who are most susceptible continues to <span class="hlt">reveal</span> new insights. Human susceptibility to adverse health effects from exposure to <span class="hlt">air</span> pollution can be related to underlying dis...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22825808','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22825808"><span><span class="hlt">Air</span>-breathing behavior and physiological responses to hypoxia and <span class="hlt">air</span> exposure in the <span class="hlt">air</span>-breathing loricariid fish, Pterygoplichthys anisitsi.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>da Cruz, André Luis; da Silva, Hugo Ribeiro; Lundstedt, Lícia Maria; Schwantes, Arno Rudi; Moraes, Gilberto; Klein, Wilfried; Fernandes, Marisa Narciso</p> <p>2013-04-01</p> <p>Hypoxic water and episodic <span class="hlt">air</span> exposure are potentially life-threatening conditions that fish in tropical regions can face during the dry season. This study investigated the <span class="hlt">air</span>-breathing behavior, oxygen consumption, and respiratory responses of the <span class="hlt">air</span>-breathing (AB) armored catfish Pterygoplichthys anisitsi. The hematological parameters and oxygen-binding characteristics of whole blood and stripped hemoglobin and the intermediate metabolism of selected tissue in normoxia, different hypoxic conditions, and after <span class="hlt">air</span> exposure were also examined. In normoxia, this species exhibited high activity at night and AB behavior (2-5 AB h(-1)). The exposure to acute severe hypoxia elicited the AB behavior (4 AB h(-1)) during the day. Under progressive hypoxia without access to the water surface, the fish were oxyregulators with a critical O2 tension, calculated as the inspired water O2 pressure, as 47 ± 2 mmHg. At water O2 tensions lower than 40 mmHg, the fish exhibited continuous apnea behavior. The blood exhibited high capacity for transporting O2, having a cathodic hemoglobin component with a high Hb-O2 affinity. Under severe hypoxia, the fish used anaerobic metabolism to maintain metabolic rate. <span class="hlt">Air</span> exposure <span class="hlt">revealed</span> physiological and biochemical traits similar to those observed under normoxic conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/20062','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/20062"><span>Sequential <span class="hlt">air</span> sampler system : its use by the Virginia Department of Highways & Transportation.</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>1975-01-01</p> <p>The Department of Highways & Transportation needs an economical and efficient <span class="hlt">air</span> quality <span class="hlt">sampling</span> system for meeting requirements on <span class="hlt">air</span> monitoring for proposed projects located In critical areas. Two sequential <span class="hlt">air</span> <span class="hlt">sampling</span> systems, the ERAI and th...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5650064','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5650064"><span>Strain diversity and host specificity in bee gut symbionts <span class="hlt">revealed</span> by deep <span class="hlt">sampling</span> of single copy protein-coding sequences</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Powell, J. Elijah; Ratnayeke, Nalin; Moran, Nancy A.</p> <p>2017-01-01</p> <p>High throughput rRNA amplicon surveys of bacterial communities provide a rapid snapshot of taxonomic composition. But strains with nearly identical rRNA sequences often differ in gene repertoires and metabolic capabilities. To assess strain-level variation within Snodgrassella alvi, a gut symbiont of corbiculate bees, we performed deep sequencing on amplicons of a single copy coding gene (minD) as well as the 16S rDNA V4 region. We surveyed honey bees (Apis mellifera) <span class="hlt">sampled</span> globally and 12 bumble bee species (Bombus) <span class="hlt">sampled</span> from two regions of the USA. The minD analyses <span class="hlt">reveal</span> that S. alvi contains far more strain diversity than is evident from 16S rDNA analysis. Many taxa inferred on the basis of 16S rDNA are shared between A. mellifera and Bombus species, but taxa inferred on the basis of minD are never shared and often are restricted to particular Bombus species. Clustering based on minD <span class="hlt">revealed</span> that gut communities often reflect host species and geographic location. Both minD and 16S rDNA analyses indicate that strain diversity is higher in A. mellifera than in Bombus species. The minD locus flanks a 16S gene, enabling development of strain-specific 16S fluorescent probes to illuminate the spatial relationship of strains within the bee gut. PMID:27482856</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23124671','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23124671"><span>Nitrogen and triple oxygen isotopes in near-road <span class="hlt">air</span> <span class="hlt">samples</span> using chemical conversion and thermal decomposition.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Smirnoff, Anna; Savard, Martine M; Vet, Robert; Simard, Marie-Christine</p> <p>2012-12-15</p> <p>The determination of triple oxygen (δ(18)O and δ(17)O) and nitrogen isotopes (δ(15)N) is important when investigating the sources and atmospheric paths of nitrate and nitrite. To fully understand the atmospheric contribution into the terrestrial nitrogen cycle, it is crucial to determine the δ(15)N values of oxidised and reduced nitrogen species in precipitation and dry deposition. In an attempt to further develop non-biotic methods and avoid expensive modifications of the gas-equilibration system, we have combined and modified <span class="hlt">sample</span> preparation procedures and analytical setups used by other researchers. We first chemically converted NO(3)(-) and NH(4)(+) into NO(2)(-) and then into N(2)O. Subsequently, the resulting gas was decomposed into N(2) and O(2) and analyzed by isotope ratio mass spectrometry (IRMS) using a pre-concentration system equipped with a gold reduction furnace. The δ(17)O, δ(18)O and δ(15)N values of nitrate and nitrite <span class="hlt">samples</span> were acquired simultaneously in one run using a single analytical system. Most importantly, the entire spectrum of δ(17)O, δ(18)O and/or δ(15)N values was determined from atmospheric nitrate, nitric oxide, ammonia and ammonium. The obtained isotopic values for <span class="hlt">air</span> and precipitation <span class="hlt">samples</span> were in good agreement with those from previous studies. We have further advanced chemical approaches to <span class="hlt">sample</span> preparation and isotope analyses of nitrogen-bearing compounds. The proposed methods are inexpensive and easily adaptable to a wide range of laboratory conditions. This will substantially contribute to further studies on sources and pathways of nitrate, nitrite and ammonium in terrestrial nitrogen cycling. Copyright © 2012 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26411943','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26411943"><span>[Measurement of Chemical Compounds in Indoor and Outdoor <span class="hlt">Air</span> in Chiba City Using Diffusive <span class="hlt">Sampling</span> Devices].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sakamoto, Hironari; Uchiyama, Shigehisa; Kihara, Akiko; Tsutake, Toyoshige; Bekki, Kanae; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki</p> <p>2015-01-01</p> <p>Indoor <span class="hlt">air</span> quality (IAQ) is a major concern, because people on average spend the vast majority of their time indoors and they are repeatedly exposed to indoor <span class="hlt">air</span> pollutants. In this study, to assess indoor <span class="hlt">air</span> quality in Chiba City, gaseous chemical compounds were surveyed using four types of diffusive sampler. Gaseous chemical compounds such as carbonyls, volatile organic compounds (VOC), acid gases, basic gases, and ozone were measured in indoor and outdoor <span class="hlt">air</span> of 50 houses throughout Chiba City in winter and summer. Four types of diffusive sampler were used in this study: DSD-BPE/DNPH packed with 2,4-dinitrophenyl hydrazine and trans-1,2-bis(2-pyridyl)ethylene-coated silica for ozone and carbonyls; VOC-SD packed with Carboxen 564 particles for volatile organic compounds; DSD-TEA packed with triethanolamine-impregnated silica for acid gases; and DSD-NH3 packed with phosphoric acid-impregnated silica for basic gases. Almost all compounds in indoor <span class="hlt">air</span> were detected at higher concentrations in summer than in winter. However, the nitrogen dioxide concentration in indoor <span class="hlt">air</span> particularly increased only in winter, which well correlated with the formic acid concentration (correlation coefficient=0.974). The compound with the highest concentrations in indoor <span class="hlt">air</span> was p-dichlorobenzene, with recorded levels of 13,000 μg m(-3) in summer and 1,100 μg m(-3) in winter in indoor <span class="hlt">air</span>. p-Dichlorobenzene in summer and nitrogen dioxide in winter are detected at markedly high concentrations. Pollution control and continuous monitoring of IAQ are indispensable for human health.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993KvanE..20...51V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993KvanE..20...51V"><span>Laser plasma at low <span class="hlt">air</span> pressure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vas'kovskii, Iu. M.; Moiseev, V. N.; Rovinskii, R. E.; Tsenina, I. S.</p> <p>1993-01-01</p> <p>The ambient-pressure dependences of the dynamic and optical characteristics of a laser plasma generated by CO2-laser irradiation of an obstacle are investigated experimentally. The change of the <span class="hlt">sample</span>'s surface roughness after irradiation is investigated as a function of <span class="hlt">air</span> pressure. It is concluded that the transition from the <span class="hlt">air</span> plasma to the erosion plasma takes place at an <span class="hlt">air</span> pressure of about 1 mm Hg. The results confirm the existing theory of plasma formation near the surface of an obstacle under the CO2-laser pulse effect in <span class="hlt">air</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18313515','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18313515"><span><span class="hlt">Air</span> filtration systems and restrictive access conditions improve indoor <span class="hlt">air</span> quality in clinical units: Penicillium as a general indicator of hospital indoor fungal levels.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Araujo, Ricardo; Cabral, João Paulo; Rodrigues, Acácio Gonçalves</p> <p>2008-03-01</p> <p>High-efficiency particulate <span class="hlt">air</span> (HEPA) filters do not completely prevent nosocomial fungal infections. The first aim of this study was to evaluate the impact of different filters and access conditions upon airborne fungi in hospital facilities. Additionally, this study identified fungal indicators of indoor <span class="hlt">air</span> concentrations. Eighteen rooms and wards equipped with different <span class="hlt">air</span> filter systems, and access conditions were <span class="hlt">sampled</span> weekly, during 16 weeks. Tap water <span class="hlt">samples</span> were simultaneously collected. The overall mean concentration of atmospheric fungi for all wards was 100 colony forming units/m(3). We found a direct proportionality between the levels of the different fungi in the studied atmospheres. Wards with HEPA filters at positive <span class="hlt">air</span> flow yielded lower fungal levels. Also, the existence of an anteroom and the use of protective clothes were associated to the lowest fungal levels. Principal component analysis showed that penicillia afforded the best separation between wards' <span class="hlt">air</span> fungal levels. Fungal strains were rarely recovered from tap water <span class="hlt">samples</span>. In addition to <span class="hlt">air</span> filtration systems, some access conditions to hospital units, like presence of anteroom and use of protective clothes, may prevent high fungal <span class="hlt">air</span> load. Penicillia can be used as a general indicator of indoor <span class="hlt">air</span> fungal levels at Hospital S. João.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT.......399C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT.......399C"><span>The study of volatile organic compounds in urban and indoor <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clarkson, Paul Jonathan</p> <p></p> <p>Chapter 1 is a review of the literature concerning the study of volatile organic compounds in the atmosphere. It examines the basic chemistry of the atmosphere and the roles that organic compounds play in it. Also investigated are the methods of <span class="hlt">sampling</span> and analysing the volatile organic compounds in the <span class="hlt">air</span>, paying particular attention to the role of solid phase <span class="hlt">sampling</span>. Chapter 1 also examines the role of volatile organic compounds on <span class="hlt">air</span> quality. Chapter 2 describes the experimental procedures that were employed during the course of this research project. Chapter 3 examines a multi-method approach to the study of volatile organic compounds in urban and indoor <span class="hlt">air</span>. The methods employed were capillary electrophoresis, high performance liquid chromatography and gas chromatography. Although good results were obtained for the various methods that were investigated Chapter 3 concludes that a more unified analytical approach is needed to the study of the <span class="hlt">air</span>. Chapter 4 investigates the possibilities of using a unified approach to the study of VOC's. This is achieved by the development of an <span class="hlt">air</span> <span class="hlt">sampling</span> method that uses solid phase extraction cartridges. By investigating many aspects of <span class="hlt">air</span> <span class="hlt">sampling</span> mechanisms the results show that a simple yet efficient method for the <span class="hlt">sampling</span> of VOC in <span class="hlt">air</span> has been developed. The SPE method is a reusable, yet reliable method that by using sequential solvent desorption has been shown to exhibit some degree of selectivity. The solid phase that gave the best results was styrene-divinyl benzene however other phases were also investigated. The use of a single gas chromatography method was also investigated for the purpose of confirmatory identification of the VOC's. Various detection systems were used including MS and AED. It was shown that by optimising the GC's it was possible to get complimentary results. Also investigated was the possibility of compound tagging in an attempt to confirm the identity of several of the compounds found</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. Their policies may differ from this site.</div> </div><!-- container --> <footer><a id="backToTop" href="#top"> </a><nav><a id="backToTop" href="#top"> </a><ul class="links"><a id="backToTop" href="#top"> </a><li><a id="backToTop" href="#top"></a><a href="/sitemap.html">Site Map</a></li> <li><a href="/members/index.html">Members Only</a></li> <li><a href="/website-policies.html">Website Policies</a></li> <li><a href="https://doe.responsibledisclosure.com/hc/en-us" target="_blank">Vulnerability Disclosure Program</a></li> <li><a href="/contact.html">Contact Us</a></li> </ul> <div class="small">Science.gov is maintained by the U.S. Department of Energy's <a href="https://www.osti.gov/" target="_blank">Office of Scientific and Technical Information</a>, in partnership with <a href="https://www.cendi.gov/" target="_blank">CENDI</a>.</div> </nav> </footer> <script type="text/javascript"><!-- // var lastDiv = ""; function showDiv(divName) { // hide last div if (lastDiv) { document.getElementById(lastDiv).className = "hiddenDiv"; } //if value of the box is not nothing and an object with that name exists, then change the class if (divName && document.getElementById(divName)) { document.getElementById(divName).className = "visibleDiv"; lastDiv = divName; } } //--> </script> <script> /** * Function that tracks a click on an outbound link in Google Analytics. * This function takes a valid URL string as an argument, and uses that URL string * as the event label. */ var trackOutboundLink = function(url,collectionCode) { try { h = window.open(url); setTimeout(function() { ga('send', 'event', 'topic-page-click-through', collectionCode, url); }, 1000); } catch(err){} }; </script> <!-- Google Analytics --> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-1122789-34', 'auto'); ga('send', 'pageview'); </script> <!-- End Google Analytics --> <script> showDiv('page_1') </script> </body> </html>