Impact/Purpose:

The main objective is to investigate human exposure to fine and coarse particles (and PAHs) from several important sources such as cooking, woodsmoke, and household cleaning. A second objective is to investigate the observed increased personal exposure (compared to indoor air concentrations measured by a fixed monitor) to particles: the so-called "personal cloud," that has been observed in many occupational and some environmental studies. A third objective is to incorporate the findings into a mass-balance indoor air quality model.

Description:

This is a continuation of an Internal Grant research project with a focus on analyzing and reporting the research results. This project will carry out controlled experiments to investigate human exposure to fine and coarse particles, black carbon (soot), and PAHs from several important sources such as cooking, woodsmoke, and household cleaning. Both source strengths and the decay rate of particles of up to 150 size fractions (including fine, coarse, and ultrafine) produced by these different processes will be determined, and compared to recent statistical estimates of these parameters from EPA's PTEAM Study. These studies will take place in occupied homes using near-real-time optical particle monitors, two real-time monitors for black carbon, and two real-time PAH monitors. Air exchange rates will be measured concurrently in all experiments to allow calculation of the decay rate of each different type and size fraction of aerosol. A second objective will be to investigate the observed increased personal exposure (compared to indoor air concentrations measured by a fixed monitor) to particles: the so-called "personal cloud," that has been observed in many occupational and some environmental studies. Three hypotheses have been proposed to explain the personal cloud: resuspension of floor dust, proximity to sources, and shedding of skin scales. All three will be investigated systematically in turn to determine the relative contribution each makes to the personal cloud. An important part of the project will be development and evaluation of a new semi-continuous gravimetric particle monitor. This monitor, based on a concept developed at Harvard University School of Public Health (one of the proposed cooperating institutions), if successfully developed, will fill an important gap in present particle monitoring methodology.

The results of the project will include extremely detailed data on the source strengths and decay rates of six size fractions of several different sources of particles, soot, and PAHs; an improved understanding of the "personal cloud;" and a new gravimetric semi-continuous particle monitor. The data on source strengths and decay rates will feed into indoor air quality models of use to risk assessors. The data on the "personal cloud" will likewise be useful in estimating exposure based on ambient and/or indoor air measurements.

Record Details:

Record Type:PROJECT

Start Date:10/01/1996

Completion Date:09/01/2001

Record ID: 56131

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Project Information:

Progress :Three full years of monitoring have been completed. A number of presentations have been given at annual conferences of ACGIH, AAAR, ISEA, etc. A contract task order has been let to create a single unified data base with all monitoring results, together with meteorological variables, to allow for cross-pollutant analyses.

ABSTRACT/ORAL

13-OCT-99 Buckley, T.J., and Wallace, L.A. Evaluation of air purification devices for control of indoor PM. PM 2000 AWMA Conference, Charleston, SC, January 24-28, 2000.

13-OCT-99 LaRosa, L., Buckley, T.J., Howard-Reed, C., and Wallace, L.A. Assessment of outdoor, indoor, and personal PM concentration differences by continuous monitoring. PM 2000 AWMA, Charleston, SC, January 25-28, 2000.

13-OCT-99 Wallace, L.A., Howard-Reed, C., LaRosa, L., and Emmerich, S.J. Monitoring particles, soot, and PAHs in a home. PM 2000 AWMA Conference, Charleston, SC, January 24-28, 2000.

13-OCT-99 Ott, W.R., Wallace, L.A., and Mage, D.T. Predicting particulate (PM-10) frequency distributions for urban populations using a random component superposition model (RCS) model. PM 2000 AWMA Conference, Charleston,

SC, January 24-28, 2000.

02-MAR-00 Howard-Reed, C., Wallace, L.A., and Emmerich, S.J. Determination of particle deposition rates for cooking and other indoor source. 19th Annual AAAR Conference, St. Louis, MO, November 6-10, 2000.

26-APR-00 Howard-Reed, C., Wallace, L.A., and Emmerich, S.J. Cooking-related particle concentrations measured in an occupied townhome in Reston, VA. Abstract presented at: ISEA 2000 Exposure Analysis in the 21st Century: Integrating Science, Policy and Quality of Life, Monterey Pennisula, CA, October 24-27, 2000.

26-APR-00 Wallace, L.A., Howard-Reed, C., and Emmerich, S.J. Multiyear real-time monitoring of particles, PAH, and black carbon in an occupied house. Abstract presented at: ISEA 2000 Exposure Analysis in the 21st Century:

Integrating Science, Policy and Quality of Life, Monterey Pennisula, CA, October 24-27, 2000.

01-MAY-00 LaRosa, L., Howard-Reed, C., and Wallace, L.A. Continuous black carbon measurements indoors and outdoors at an occupied house for one year. Abstract presented at: ISEA 2000 Exposure Analysis in the 21st Century:

Integrating Science, Policy and Quality of Life, Monterey Pennisula, CA, October 24-27, 2000.



Relevance :These studies can help establish important sources, both outdoor and indoor, of particle exposure, and provide rough estimates of the source strengths. Data on particle deposition rates will also be useful to indoor air quality models. In addition, some components of personal exposure to particles (e.g, the personal cloud) will be better understood.

Clients :Other ORD labs, Office of Radon and Indoor Air

Project IDs:

ID Code :1977

Project type :OMIS