The Mickey Leland National Urban Air Toxics Research Center
Founded 1990, Incorporated 1991
ONGOING RESEARCH

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Ongoing Research Projects

Abstract
Relationship Between Indoor, Outdoor, and Personal Air
(Clifford Weisel, Ph.D.)

    The Health Effects Institute (HEI) and the Mickey Leland National Urban Air Toxics Research Center (NUATRC) are jointly funding RIOPA, a large urban air toxics project that is comprised of three studies initially independently funded:

    Because the two HEI studies complemented and added to the initial study funded by NUATRC, staff from both organizations attempted to treat the three studies as one so that the results will be reported in a coherent way.  The late Dr. Cass, Drs, Samet, and Speizer provided oversight for the HEI components, and oversight by the NUATRC component is being provided by Drs. Brauer, Guiseppi-Elie, and Karol and Bailar. 

    The RIOPA project tests the hypothesis that personal exposure to air toxics is influenced by outdoor sources of these air toxics.  It involves 3 cities with different air pollution source profiles: Los Angeles, California is dominated by mobile sources; Houston, Texas is dominated by industrial point sources; and Elizabeth, New Jersey includes a mixture of mobile and point sources.  In each city, 100 homes were monitored for 48 hours in each of the 2 seasons.  The homes were monitored indoors and outdoors for PM2.5 VOCs, and aldehydes.  In addition, personal exposure to PM2.5, VOCs, and aldehydes, and in-vehicle exposure to aldehydes were measured for residents of these homes.

Publications
Relationship Between Indoor, Outdoor, and Personal Air
(Clifford Weisel, Ph.D.)

  1. Zhang, J.; Zhang, L.; Fan, Z.; and Ilaqua, V.  “Development of the personal aldehydes and ketones sampler (PAKS) based upon DNSH derivatization on solid sorbent.”  Environmental Science & Technology 2000, 34(12): 2601-1607.

  2.  CP Weisel. “Assessing Exposure to Air Toxics Relative to Asthma.” Environmental Health Perspectives August 2002, 110 (Sup 4): 527-537

  3.  Y Naumova et al, “Polycyclic Aromatic Hydrocarbons in the indoor and Outdoor Air of Three Cities in the US.”  Environmental Science & Technology 2002, 36: 2552-2559.

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Abstract
Development of a New Generation Personal Sampler for Particulate Matter
 (Constantine Sioutas, Ph.D.)

    The award was made to Dr. Constantinos (Costas) Sioutas of the University of California (USC), for the development of a new generation personal sampler for particulate matter (PM).  The purpose of this project is to design a personal cascade impactor sampler (PCIS) for PM that will allow for both (1) separation of particles by size and (2) analyses of these particles for their toxic metal content.  The sampler operate in conjunction with SKC, Inc.’s high efficiency air sampling pump.

    The PCIS is a miniaturized cascade impactor, consisting of four impaction stages followed by an after-filter.  Particles will be separated in the following aerodynamic particle diameter ranges: < 0.25, 0.25-0.5, 0.5-1.0, 1.0-2.5, and 2.5-10 mm.  Particles in the size-range of 0.25-10 mm are accelerated in rectangular shaped nozzles and collected on a small commercially available 25-mm filter made up of quartz. Use of these small substrates reduce the required liquid volume for chemical extraction and analysis.  The quartz filter eliminates particle bounce and allows sufficient material to be collected to conduct gravimetric analyses as well as analyses of the toxic metals using ICP-MS methodology.

Publications
Development of a New Generation Personal Sampler for Particulate Matter
 (Constantine Sioutas, Ph.D.)

  1.  Development and evaluation of a personal cascade impactor sampler (PCIS), Journal of Aerosol Science, Volume 33, Issue 7, July 2002, Pages 1027-1047
    Chandan Misra, Manisha Singh, Si Shen, Constantinos Sioutas and Peter M. Hall
  2. Misra, C., Singh, M., and Sioutas, C. Field evaluation of a personal monitor for size-dependent measurement of mass and chemical composition of individual exposure to particulate matter (Manuscript submitted to Atmospheric Environment, November- December 2002.)
  3. Dr. Sioutas and his doctoral student, Manisha Singh, have authored a book chapter entitled "Assessment of Exposure to Airborne Particles" Book Project: Airborne Particles and Settled Dust in the Indoor Environment Publisher:  WILEY-VCH, Weinheim, Germany, Editors: Prof. Dr. Lidia Morawska and Dr. Tunga Salthammer.

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Abstract
Development of a High Efficiency Pump for the Personal Particulate Matter Sampler
 (Peter Hall, SKC, Inc.)

    In January 2000, NUATRC released RFP 2000-01 to develop a high efficiency personal air pump, to be used with the air sampler built by Dr. Sioutas of USC.  A contract was awarded to SKC, Inc., effective October 1, 2000.

Specifications
Development of a High Efficiency Pump for the Personal Particulate Matter Sampler
 (Peter Hall, SKC, Inc.)

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Abstract
Air Toxics and Asthma in Children
 (George Delclos, M.D., M.P.H.)

    This is a 2-year study and the contract for the study was signed in December 2001. The objective of this project is to conduct a prospective, pilot panel study to investigate the association between exposure to oxygenated air toxics (total carbonyl concentration) and asthma health outcomes among labile, persistent asthmatic middle school children in Houston, using a repeated measures design over a 12 month period. The study population will center on labile, persistent asthmatics on the basis that they are likely to manifest greater variability in health outcomes following exposure to airborne stimuli. Given the highly individual nature of asthma, as well as budget and time constraints, the most efficient study design is one of repeated measures of health outcomes and relevant exposure variables over time, in which each participant serves as her/his own control.  Four 1-week measurement periods, for each of the main independent (exposure) and dependent (health outcome) variables will be performed over a 12-month observation period.  Repeated measurement of established confounder variables would also be performed serially over the 12-month period.  The results of this study should make an important contribution to the body of knowledge regarding important environmental triggers of asthma in children.  Specifically, this is the first effort, to the best of our knowledge, to examine the relationship between measured personal exposure to carbonyl-containing toxic air pollutants and aggravation of asthma.  This survey of exposures in a susceptible population is especially important, because very little is known about the variability of microenvironmental levels of these compounds, and the major determinants of concentrations and exposures.

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Abstract
Cardiopulmonary Responses to Particulate Exposure
(D.C. Christiani, T. Smith, R. Hauser, P. Williams, M. Serigran)

    Population-based epidemiologic studies of communities in the United States have revealed a consistent association between ambient particulate air pollution and increases in morbidity and mortality.  The observed increases result from both respiratory and cardiovascular diseases.  Similar associations have been observed for rates of hospital admissions for respiratory and cardiovascular diseases for subjects over age 65.  These ambient exposures are to levels of particulates many times lower than occupational exposures faced by workers in a variety of industries, including manufacturing, construction, transportation and electric-power generation.   The objective of this proposal is to investigate the role of occupational exposure particlates in the development of respiratory and cardiac responses in boilermakers with and without chronic bronchitis.  We will employ a detailed continuous-responses assessment to PM2.5 with repeated measures of biologic and physiologic markers of response.  Specific hypotheses to be tested will included: (1) occupational exposure to fuel-oil ash particles induced airway inflammation as reflected in increased expired NO, and airflow obstruction as reflected in decreases in peak flow (PERF) and FEV1; (2) particulate exposure will result in acute changes in cardiovascular function, as reflected in changes in heart rate, heart-rate variability and blood pressure; (3) particulate exposure results in increased serum fibrinogen levels, a known risk factor for cardiovascular disease; and (4) chronic bronchitis predisposes particulate-exposed workers to changes in cardiac function.   The experimental approach will be an epidemiologic study employing a prospective, repeat-measurement design assessing several biological parameters in relation to exposure.  The expected results will clarify the relationship between exposure to oil-combustion ash and human cardiopulmonary responses in both normal and chronic bronchitic populations.  Clarification of such exposure-response relationships will have important implications for preventive efforts aimed at reducing morbidity and mortality from exposure to respirable particulates.

Publication
Cardiopulmonary Responses to Particulate Exposure
(D.C. Christiani, T. Smith, R. Hauser, P. Williams, M. Serigran)

  1. Magari, S.R., Hauser, R., Schwartz, J., William, P.L., Smith, T.J., Christiani D.C., The association of Heart-Rate variability with Occupational and environmental Exposure to Particulate Air Pollution. Circulation, Vol. 104,968-991, 2001

  2. Magari, SR; Schwartz, J, Williams PL, Hauser R, , Smith TJ, Christiani, DC.  The association between personal measurements of environmental exposure to particulates and heart rate variability. Epidemiology 2002;13:305-310.

  3. Magari, SR; Schwartz, J, Williams PL, Hauser R, Smith TJ, Christiani, DC.  Association of particulate air metal concentrations with heart rate variability.  Environmental Health Perspectives, September 2002 (110/9) pp 875-880

  4. Jee Young Kim, MP. Ward, R Hauser, S Mukherjee, R F Herrick and DC.  Christiani, Association of Exhales Nitric Oxide with Occupational Particulate Exposure.  Submitted to American Journal of Respiratory Critical Care Medicine, January, 2002

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Abstract
Testing the Metals Hypothesis in Three Cities:  Daily Associations Between Respiratory Outcomes and Airborne Fine Particulate Metal Species
(C.S. Claiborn, R.H. Filby, T.V. Larson, L. Sheppard)

    We propose to test the toxic metals and transition metals hypothesis by evaluating the associations between particulate toxic metals (Sb, As, Cr, Co, Mn, Hg, Se, Cd, Ni) and additional transition II metals (Ti, V, soluble Fe) and several respiratory outcomes to include emergency department visits for asthma, hospital admissions, and total respiratory mortality.  This will be accomplished using a time series epidemiological study comparing three cities with very different particulate matter source profiles:  spokane (biomas burning); Phoenix (motor vehicles); and Baltimore (steel mills).  Particulate metals content will be determined using a combination of energy-dispersive x-ray flourescence (EDXRF) and instrument neutron activation analysis (INAA).  The study will be leveraged three previous fine particulate studies for which daily fine and coarse particulate samples were collected and analyzed via EDXRF.   We will analyze archived, daily particualte samples from Phoenix (2 years, 1995-1997), Baltimore (1 year, 1997-1998), and Spokane (4 years, 1995-1998), via INAA to fully characterize the atmospheric particulate metal content for each city.  In addition, to increase the power of the data set in Spokane, we will collect and analyze an additional three year worth samples data in Spokane.  The additional samples collected will increase the total duration of the study to 6 years, which will be sufficient to obsere statistically significant associations between particulate metal air pollution and respiratory outcomes. 

    This project will test the metals hypothesis by examining associations between health outcomes and particulate matter, as well as the relative toxicity of specific particulate metal species.

Publications
Testing the Metals Hypothesis in Three Cities:  Daily Associations Between Respiratory Outcomes and Airborne Fine Particulate Metal Species
(C.S. Claiborn, R.H. Filby, T.V. Larson, L. Sheppard)

  1. J.K. Vaughan, C.S. Claiborn, and D. Finn (2001). April 1998 Asian Dust Event Over the Columbia Plateau, Journal of Geophysical Research, 106:18,381-18,402.

  2. CS Claiborn, T Larson, L Sheppard; Testing the Metals Hypothesis in Spokane, Washington; Environ Health Perspec, August 2002; 110/Sup 4, pp547-552

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Abstract
Source Apportionment of Indoor PAHs in Ueban Residence Homes
(A. Li, R. Wadden, P. Scheff)

    The basic hypotheses for the project are that polycyclic aromatic hydrocarbons (PAHs) in outdoor air can contribute significantly to the PAHs in homes, and that PAHs can also be generated from indoor activities and sources.  The objectives of this study are to assess the relative contributions from outdoor sources to the indoor PAHs in urban residence homes, to evaluate the indoor sources, and to examine the factors that control or modify the indoor air concentrations of PAHs.

    Ten non-smoker homes in south Chicago will be sampled once per month for a year for PAHs in indoor air.  simultaneous outdoor samples will be collected at locations within 10 meters from the home.  Continuous measurement of CO2, temperature and relative humidity will be carried out.  condition of the home and surrounding activities, including occupancy, presence of indoor sources such as smoking and cooking, type of furnishings. garage attachment, operation of heating/cooling systems, mothball and other chemical usage, etc., will be recorded at the time of sampling.   PAH fingerprints are to be established for potential indoor sources.  Seasonal variation of PAH exposure will be evaluated.  the PAHs will be analyzed based on EPA standard methods.  The analysis includes Soxhlet extraction of the sampler filter/sorbent cartridges, silica-gel cleanup, and GC/MS or GC/FID quantification.   QA/QC procedures will be incorporated into entire sampling and analytical process.

    A simplified one-compartment steady state mass balance model will be used to calculate the indoor ventilation and air infiltration rate based on CO2 data, and to estimate overall PAH indoor emission rate.  A receptor model will be used to apportion the sources of indoor PAHs.  Indoor sources including cigarette smoking, fry-cooking, meat-baking/broiling, fireplace wood burning, garage activities, mothball usage, and gas heater, along with the outdoor air as a single source, will be examined.  Computer SAS program will be used for all calculations.

    The end result of this project will be a quantitative description of household exposure and sources of PAHs.  The comprehensive data sets developed in this project will provide the basis for exposure assessment, and the source apportionment models will be powerful tools for the purpose of source identification and exposure assessment.  Such efforts will foster our ability to assess human exposure without the need for detailed environmental measurement, and will lead to the future development of exposure reduction strategies.

Publications
Source Apportionment of Indoor PAHs in Ueban Residence Homes
(A. Li, R. Wadden, P. Scheff)

  1. Large Volume Injection PTV-GC-MS Analysis of Polycyclic Aromatic hydrocarbons in Air and Sediment Samples. Felice Norlock, An Li, Jae-Kil Jang, Todd Schoonover, Journal of the Air and Waste Management Association January 2002, 52:19-26.
  2. Optimization of Silica Gel Chromatographic Cleanup/Fractionation Procedure for Analyzing PAHs and PCB.  In sediments. J. Jang, An Li. Chemosphere 44, 1439-1445, 2001

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Abstract
VOC Exposure in an Industry-Impacted Community
(T.J. Buckley, D. Payne-Sturges, V.M. Weaver)

    The primary goal of the proposed study is to provide exposure information to a community concerned over their health hazard due to the intensity and proximity of industrial sources.  This overarching goal will be achieved through multiple objectives.  first, indoor and outdoor VOC concentrations will be measured and the contribution of VOCs from outdoor sources penetrating indoors will be evaluated.   this will provide the community with a perspective of the relative importance of indoor and outdoor sources.  second, personal exposure and a biomarker for benzene exposure, trans, trans-muconic acid (ttMA) will be measured for the industry impacted community and for a reference group.  The reference group will be defined in consultation with the community to provide a perspective of how different or similar their exposures are to a comparison group of their choosing.  Third, we will evaluate seasonal changes in exposure by repeating the monitoring during a second season for a subset of individuals to provide the community with information about how exposures and their sources can change from season to season.  Lastly, we will assess within home correlation in VOC exposure and ttMA between partners and their children living within the same home.  This will provide exposure information on a potentially susceptible subpopulation, i.e.. children, and the paired monitoring may suggest age-related differences in benzene metabolism.

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Abstract
Columbia Personal Exposure Study  
(P.L. Kinney, S. Chillrud, M. Aggarwal, H. Ozkaynak, L.M. Altshul, S.S. Ramstrom)

    Only limited data exist on personal exposures to toxic urban air pollutants in representative populations of urban-dwelling Americans.  We propose to study personal exposures to urban air toxics among high school students living in New York city and Los Angeles.  The study will yield information on variations in exposure a) across two major metropolitan areas that differ in source mixes and meteorologic characteristics, b) over space within each city, c) over seasons, and d) over days within seasons.  The main focus of the air monitoring will be on volatile organic compounds (VOCs), aldehydes, PM2.5 mass, and metals on 48 hour integrated samples.  Subsets of measurements will address ambient and personal exposures to soluble metals, sulfate, nitrate, and ammonium ions, and indoor levels of the pesticide chlordane.  the specific aims of the project are to: 1) describe and compare weekday and weekend personal exposures to urban air toxics in two representative groups of 30 high school students (NYC and LA), and analyze seasonal changes in exposures and activity patterns; 2) evaluate the contributions of indoor and outdoor air toxics concentrations to personal exposures in winter and summer, taking into account individual time/activity patterns and home ventilation rates; 3) assess the contributions of a range of source categories to personal, outdoor, and/or indoor exposures using data on individual VOCs, aldehydes, and metals; 4) characterize personal exposures to the soluble fractions of selected metals, and correlate these measurements with simultaneous fixed-site outdoor measurements, and 5) develop and design a methodology for a nationwide study addressing personal exposures to urban air toxic pollutants.

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Abstract
EOHSI Personal Exposure Study
(C.P. Weisel, M. Morandi, T.H. Stock, B. Turpin, J. Zhang, S. Colome, D.M. Spektor)

    The major objectives of the proposed research are a) to estimate the fraction that outdoor sources contribute to indoor and personal air concentrations of volatile organic compounds (VOCs), aldehydes and respirable particulate matter (PM2.5) in three distinct major urban centers in CA, TX, and NJ, and b) to estimate the exposures to populations living in the three urban centers from outdoor air toxic emissions based on residential air exchange rates and the measured relationship between outdoor air concentrations and both the indoor and personal air concentrations.  The major hypotheses to be tested are that 1) in residences immediately adjacent to outdoor sources a measurable and significant proportion of the personal exposures, breath concentrations and indoor air concentrations to selected VOCs, aldehydes and PM2.5 are contributed by outdoor point and area sources under appropriate meteorological conditions, and that 2) residential air exchange rate is a major determinant of the influence of outdoor air concentration on indoor air and personal exposure; therefore the influence of outdoor air on indoor and personal air can be predicted for a large segment of the population within the proposed study areas from outdoor air concentrations and air exchange rates.

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Abstract
NUATRC-NCHS Collaborative Project

    This is a collaborative project with the National Center for Health Statistics (NCHS) and was a component of the National Health and Nutrition Examination Survey (NHANES) for the years 1999-2001.  During that time, information was collected from study subjects on personal exposures to a group of volatile organic compounds (VOCs).  Information on levels of exposure to these compounds is essential to determine the need for regulations to reduce the levels of hazardous air pollutants to which the general population is exposed.

Personal exposures were assessed using small passive sampling badges worn by subjects for periods of 48-72 hours.  Information on activities conducted during the exposure periods was also collected using a special questionnaire, and blood samples were collected as well.

The data will be used to characterize the distribution of personal exposures to this group of VOCs, and will be the first nationally-based set of exposure data of this type.  Other objectives are: (1) to examine the relationship between personal exposures to VOCs and demographic, economic, and behavioral characteristics of study subjects; and (2) to investigate possible associations between personal exposures to VOCs and selected measures of health status.  The 1999-2000 data set is scheduled for release in 2003.

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