2002 Progress Report: Acute Cardiopulmonary Responses to Fine Particulate Pollution and Copollutant Oxidant Gases in Los Angeles

EPA Grant Number: R827999
Title: Acute Cardiopulmonary Responses to Fine Particulate Pollution and Copollutant Oxidant Gases in Los Angeles
Investigators: Gong, Henry , Sioutas, Constantinos
Institution: University of Southern California , Rancho Los Amigos Medical Center
EPA Project Officer: Chung, Serena
Project Period: March 15, 2000 through March 14, 2003 (Extended to January 14, 2004)
Project Period Covered by this Report: March 15, 2002 through March 14, 2003
Project Amount: $613,894
RFA: Airborne Particulate Matter Health Effects (1999) RFA Text |  Recipients Lists
Research Category: Air , Health Effects , Particulate Matter

Objective:

The objectives of this research project are to:

1. Perform realistic controlled exposures of human volunteers to ambient particulate matter (PM), representing an extreme, but realistic, combination of exposure conditions and vulnerable people. The experimental atmospheres contain approximately 200 µg/m3 concentrated ambient fine PM and 0.4 ppm nitrogen dioxide (NO2), separately and in combination. The volunteer subjects are healthy elderly adults and elderly adults with chronic obstructive pulmonary disease (COPD).

2. Document short-term effects of the above exposures on sensitive measures of cardiopulmonary health. These include symptom inventories, conventional clinical tests of respiratory function, measures of airway inflammation on induced sputum samples, measures of systemic inflammation and hemostasis on peripheral blood samples, and measures of cardiac ischemia and heart rhythm alterations from Holter electrocardiograms.

Progress Summary:

Work Completed to Date

As of September 2002, 19 subjects—6 healthy and 13 with COPD—have completed exposure studies. To meet a submission deadline for a conference presentation, interim statistical analyses have been performed on this group. Highlights of the interim results are presented in this report.

Interim Results for 19 Subjects: Exposures

Table 1 shows means ± standard deviations of concentrations measured in the exposure chamber in filtered air (FA), 0.4 ppm NO2, concentrated ambient particle (CAP), and combined exposures. Generated NO2 concentrations were always close to the target, but non-NO2 exposures showed lower, variable concentrations reflecting concurrent outdoor NO2 levels. CAP concentrations were more variable because of the greater difficulty in generating and monitoring CAP, but averaged close to the target. Ultrafine (PM0.1) particle concentrations averaged near 7 µg/m3, and did not vary appreciably across the four different exposure conditions, because these particles were neither concentrated nor filtered effectively. Coarse (PM10 – PM2.5) particles averaged near 20 µg/m3 in CAP and combined exposures, versus 7 µg/m3 in filtered air and NO2 exposures.

Table 1. PM and NO2 Concentrations Measured in the Exposure Chamber

Condition
PM, µg/m3
NO2, ppb
Filtered Air
24 ± 11
35 ± 31
NO2
23 ± 12
402 ± 10
CAP
194 ± 26
45 ± 21
CAP + NO2
205 ± 50
399 ± 11

Interim Results for 19 Subjects: Responses

No meaningful changes in symptoms, spirometric test results, or induced-sputum assays have been found that could be attributed to NO2 or CAP exposure. Arterial O2 saturation (SaO2) at exercise during exposure, as measured by fingertip pulse oximeter, showed statistically significant (P < 0.01) negative changes associated with CAP (estimated mean change -0.4percent) and NO2 (estimated mean change -0.2 percent). These losses appeared to be additive in the combined exposure, and were not significantly different between healthy and COPD subjects. Figure 1 below summarizes these results. Resting SaO2 during exposure showed smaller, but significant, negative effects of CAP and NO2. Pre-exposure resting SaO2 showed a negative association with prior 24-hour mean ambient PM10 (averaged from two monitoring stations near the laboratory) for all 19 subjects: the slope estimate ± standard error was -0.029 ± 0.011 percent HbO2/(µg/m3) (P < 0.02). The effect was more obvious in COPD subjects (slope estimate -0.037, P < 0.05) than in healthy subjects (slope estimate -0.012, not significant).

Figure 1. Exercise SaO2 During Exposure

Future Activities:

Five more subjects are to be studied, with recruitment and screening in late 2002, and exposures in early 2003. A no-cost extension of the project will be requested to allow completion. One reason for the extension is that recruitment of subjects with COPD who satisfy the inclusion and exclusion criteria has been difficult. The rate of volunteering has been less than hoped for, and a substantial percentage of prospective volunteers have either too severe cases of the disease (requiring continuous oxygen therapy) or too mild cases of the disease (baseline lung function within normal limits). Thus, recruitment efforts are being conducted for a longer time and over a wider area.

Journal Articles:

No journal articles submitted with this report: View all 6 publications for this project

Supplemental Keywords:

ambient air, mobile sources, risk assessment, health effects, human health, sensitive populations, dose response, elderly, nitrogen oxides, atmosphere, concentrated particulates, nitrogen dioxide, sensitive populations, susceptibility, chronic obstructive pulmonary disease, COPD, Los Angeles, air toxics, genetic susceptibility, particulate matter, PM, tropospheric ozone, acute health effects, California, CA, air contaminant exposure, air pollution, air quality, airway epithelial cells, cardiopulmonary effects, cardiopulmonary response, cardiopulmonary responses, chemical mixtures, chronic health effects, copollutants, combustion-related pollutants, copollutant exposures, elderly adults, environmental hazard exposures, fine particles, high-risk groups, human exposure, human susceptibility, inhaled, inhaled pollutants, lung inflammation, oxidant gas, particulate exposure, sensitive populations, stratospheric ozone, susceptible subpopulations., RFA, Health, Scientific Discipline, Air, Geographic Area, Waste, particulate matter, air toxics, Environmental Chemistry, Health Risk Assessment, State, Risk Assessments, Susceptibility/Sensitive Population/Genetic Susceptibility, Biochemistry, genetic susceptability, tropospheric ozone, Atmospheric Sciences, Biology, Incineration/Combustion, copollutant exposures, elderly adults, health effects, sensitive populations, cardiopulmonary responses, fine particles, PM 2.5, stratospheric ozone, airway epithelial cells, inhaled pollutants, combustion-related pollutants, air pollution, chemical mixtures, susceptible subpopulations, cardiopulmonary response, chronic health effects, human exposure, lung inflammation, oxidant gas, particulate exposure, cardiopulmonary effects, Acute health effects, highrisk groups, inhaled, PM, PM2.5, chronic obstructive pulmonary disease, human susceptibility, California (CA), air quality, human health risk, toxics, concentrated particulate matter, environmental hazard exposures, air contaminant exposure

Relevant Websites:

http://www.scpcs.ucla.edu Exit

Progress and Final Reports:

Original Abstract
  • 2000 Progress Report
  • 2001
  • Final Report