Skip common site navigation and headers
United States Environmental Protection Agency
Exposure Research
Begin Hierarchical Links EPA Home > Research & Development > Exposure Research > Publications/Presentations > End Hierarchical Links

 

The Use of Light Scattering Data to Estimate the Contribution of Indoor-and Outdoor-Generated Particles to Indoor Air

spacer
spacer
Abstract: Many epidemiologic studies have shown an association between adverse health effects and particulate concentrations measured at centrally located sites. Other studies have been conducted to examine relationships between personal exposures and central site measurements. Few studies quantify the contribution of indoor and outdoor sources to personal exposures, as particles in these two environments differ in sources and composition, and exhibit temporal and between-residence variability. This study is a subset of a larger exposure assessment study conducted between October 99 and May 01. Subjects were recruited throughout the metropolitan Seattle area, including 67 elderly and 18 pediatric asthmatics. Particle mass and light scattering were monitored on 19 subjects and at 85 residences, including 42 apartments or group homes, and 43 private homes. This paper uses a censoring technique to identify and remove indoor sources from the continuous light scattering measurements. We then apply a mass balance model to the censored time series data to estimate the contribution of indoor- and outdoor-generated particles to indoor air and to personal air. The real-time personal exposure measurements are combined with the real-time indoor and outdoor particle measurements, time-activity-location information, potential particle events, and home ventilation logs to determine the contributions from various indoor and outdoor particle sources to total personal PM exposure. The particle infiltration efficiency averages 0.53 plus/minus 0.25 and differs significantly across dwelling types and by season. Despite having higher outdoor particle concentrations and spending more time outdoors, the pediatric subjects, as compared to elderly subjects, have no higher exposure to ambient particles.

This paper has been reviewed in accordance with US Environmental Protection Agency's peer and administrative review policies and approved for publication.
spacer
Citation:Allen, R., T. V. Larson, L. A. Wallace, and L. S. Liu. The Use of Light Scattering Data to Estimate the Contribution of Indoor-and Outdoor-Generated Particles to Indoor Air. Presented at International Society of Exposure Analysis 2002 Conference, Vancouver, Canada, August 11-15, 2002.
spacer
spacer
Contact: Liz Hope - (919) 541-2785 or hope.elizabeth@epa.gov
spacer
Division: Human Exposure & Atmospheric Sciences Division
spacer
Branch: Human Exposure Analysis Branch
spacer
Product Type: Abstrct/Oral
spacer
Presented: 08/11/2002
spacer
Related Entries:
spacer
Bullet Item Exposure Relationship of Personal Exposure of High-Risk Subpopulations to Ambient Concentrations of Fine Particles.
spacer Relationship Reason:   A Project of the Product
spacer
spacer
spacer

 

ORD Home | Search EPA | Search NERL | Search EIMS | Contacts | Help

 
Begin Site Footer

EPA Home | Privacy and Security Notice | Contact Us

Last Updated on Monday, October 22, 2007
URL: http://cfpub.epa.gov