TOXICOLOGICAL EVALUATION OF REALISTIC EMISSIONS OF SOURCE AEROSOLS (TERESA): APPLICATION TO POWER PLANT-DERIVED PM2.5

Rohr, Annette

Electric Power Research Institute

关键词: Respiration;    Aerosols;    Cytology;    Lymphokines;    Animals;   

DOI  :  10.2172/859444
RP-ID  :  none
RP-ID  :  FC26-03NT41902
RP-ID  :  859444

美国|英语

来源: UNT Digital Library

【 摘 要 】

This report documents progress made on the subject project during the period of March 1, 2005 through August 31, 2005. The TERESA Study is designed to investigate the role played by specific emissions sources and components in the induction of adverse health effects by examining the relative toxicity of coal combustion and mobile source (gasoline and/or diesel engine) emissions and their oxidative products. The study involves on-site sampling, dilution, and aging of coal combustion emissions at three coal-fired power plants, as well as mobile source emissions, followed by animal exposures incorporating a number of toxicological endpoints. The DOE-EPRI Cooperative Agreement (henceforth referred to as ''the Agreement'') for which this technical progress report has been prepared covers the performance and analysis of field experiments at the first TERESA plant, located in the Upper Midwest and henceforth referred to as Plant 0, and at two additional coal-fired power plants (Plants 1 and 2) utilizing different coal types and with different plant configurations. During this reporting period, fieldwork was completed at Plant 1, located in the Southeast. Stage I toxicological assessments were carried out in normal Sprague-Dawley rats, and Stage II assessments were carried out in a compromised model (myocardial infarction-MI-model). Normal rats were exposed to the following atmospheric scenarios: (1) primary particles; (2) oxidized emissions; (3) oxidized emissions + secondary organic aerosol (SOA)--this scenario was repeated; and (4) oxidized emissions + ammonia + SOA. Compromised animals were exposed to oxidized emissions + SOA (this scenario was also conducted in replicate). Stage I assessment endpoints included breathing pattern/pulmonary function; in vivo chemiluminescence (an indicator of oxidative stress); blood cytology; bronchoalveolar lavage (BAL) fluid analysis; and histopathology. Stage II assessments included continuous ECG monitoring via implanted telemeters and blood chemistry (complete blood count, circulating cytokines (interleukins-1 and -6), C-reactive protein (CRP), tumor necrosis factor alpha (TNF-{alpha}), and endothelin-1). Only a subset of exposure data was available at the time of preparation of this report. Continuous PM{sub 2.5} mass (TEOM) results indicate a mass concentration of 14 {micro}g/m{sup 3} for the primary particle scenario, and a range of 151 to 385 {micro}g/m{sup 3} for the oxidized emissions scenarios. Toxicological results obtained to date from Plant 1 indicate subtle biological responses to some of the exposure scenarios. We observed statistically significant changes in several breathing pattern parameters, including tidal volume and frequency. For one scenario (oxidized emissions + SOA), we observed a significant increase in Enhanced Pause (Penh), a parameter that may reflect airflow restriction. However, the respiratory changes are very subtle and do not present a clear picture of a particular respiratory effect (e.g., airway restriction, sensory irritation, or pulmonary irritation). A significant increase in lung chemiluminescence (a marker of oxidative stress in lung tissue) in exposed animals (vs. air-exposed controls) was observed in animals exposed to oxidized emissions + SOA. No changes were observed in heart tissue, nor in any other scenario. Stage II assessments were conducted to the secondary + SOA scenario; ECG and blood analysis data are pending. Planning was initiated for Plant 2, located in the Midwest. Because of the requirement for both the FGD and the SCR to be concurrently operational for appropriate reaction conditions, fieldwork at Plant 2 is scheduled for Summer 2006. During the next reporting period, we will complete all remaining exposure and toxicological analyses for Plant 1, and the next semiannual report will include a detailed description of these data and their interpretation. We are also in the process of preparing a topical report for Plant 0.