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RELATING PERSONAL PM AND PM-ASSOCIATED ELEMENTAL CARBON EXPOSURES TO CARDIOVASCULAR AND PULMONARY SYMPTOMS IN A HIGH-RISK SUBPOLULATION
Citation:
Kendall, M., S. I. Hsu, P. Lopez, L A. Wallace, AND M. Lippmann. RELATING PERSONAL PM AND PM-ASSOCIATED ELEMENTAL CARBON EXPOSURES TO CARDIOVASCULAR AND PULMONARY SYMPTOMS IN A HIGH-RISK SUBPOLULATION. Presented at International Society of Exposure Analysis 2002 Conference, Vancouver, Canada, August 11-15, 2002.
Impact/Purpose:
The primary study objectives are:
1.To quantify personal exposures and indoor air concentrations for PM/gases for potentially sensitive individuals (cross sectional, inter- and intrapersonal).
2.To describe (magnitude and variability) the relationships between personal exposure, and indoor, outdoor and ambient air concentrations for PM/gases for different sensitive cohorts. These cohorts represent subjects of opportunity and relationships established will not be used to extrapolate to the general population.
3.To examine the inter- and intrapersonal variability in the relationship between personal exposures, and indoor, outdoor, and ambient air concentrations for PM/gases for sensitive individuals.
4.To identify and model the factors that contribute to the inter- and intrapersonal variability in the relationships between personal exposures and indoor, outdoor, and ambient air concentrations for PM/gases.
5.To determine the contribution of ambient concentrations to indoor air/personal exposures for PM/gases.
6.To examine the effects of air shed (location, season), population demographics, and residential setting (apartment vs stand-alone homes) on the relationship between personal exposure and indoor, outdoor, and ambient air concentrations for PM/gases.
Description:
Sensitive subpopulations such as COPD patients have been shown to be especially susceptible to the effects of PM exposure. Proximity to traffic has been shown to be a predictor of PM effects in susceptible populations. Elemental carbon (EC) has been demonstrated to be a good indicator of combustion emissions, and in urban PM is a useful indicator of the diesel traffic contribution to PM concentrations. Extremely little personal EC exposure data exists, even though diesel exhaust exposure has been linked to cancer and the exacerbation and even onset of asthma.
In this study, the personal exposures of COPD patients to PM10 and EC were monitored over 12 days during winter and summer. Simultaneous measurements of cardiovascular and pulmonary change indicators (pulse rate, blood oxygen content and lung function) were also made in order to relate particle concentrations with cardio-respiratory disease symptoms. A group of eight individuals were monitored during summer and winter sampling campaigns in 2000-2001. Personal exposures to PM10 and EC were measured using both personal sampling pumps to monitor 24 hour means on Teflon filters, and personal photometer (DataRAMs [pDRs], MIE Inc.) to identify short-term PM peaks. Co-located pDRs compared very favorably to central station TEOM monitors in identifying short-term peak concentrations. Teflon filters were subsequently analyzed using a light reflectance method (EEL reflectometer) to identify personal elemental carbon concentrations, following construction of a reflectance-absorption coefficient calibration curve. Time activity and symptom diaries were also filled in by all participants in order to identify micro-environments in which participants spent the majority of time, and to identify where peak PM concentrations coincided with specific activities or locations. Indoor and outdoor PM10 concentrations were also measured.
Personal PM10 concentrations were higher than indoor micro-environmental PM10 concentrations. EC was a significant proportion of the personal PM samples. Filter and pDR sampler results were correlated, but correlations varied from subject-to-subject and depended on specific activities. pDR samplers identified specific peak exposures during the sampling periods, which, in some cases, could be related to specific activities. Relationships between PM concentrations and health indicators were complex and no clear pattern emerged within this group.
This work was funded by EPA cooperative agreement #CR827164. This abstract has been reviewed by EPA and approved for publication.