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ACUTE PULMONARY TOXICITY OF PARTICULATE MATTER (PM) FILTER EXTRACTS IN RATS: COHERENCE WITH EPIDEMIOLOGICAL STUDIES IN UTAH VALLEY RESIDENTS
Citation:
Dye, J A., J R. Lehmann, J K. McGee, D. W. Winsett, A. D. Ledbetter, J. I. Everitt, A J. Ghio, AND D L. Costa. ACUTE PULMONARY TOXICITY OF PARTICULATE MATTER (PM) FILTER EXTRACTS IN RATS: COHERENCE WITH EPIDEMIOLOGICAL STUDIES IN UTAH VALLEY RESIDENTS. ENVIRONMENTAL HEALTH PERSPECTIVES 109(3):395-403, (2001).
Description:
Epidemiologic reports by C. A. Pope III et. al. demonstrated that in the Utah Valley, closure of an open hearth steel mill over the winter of 1987 was associated with reductions in respiratory disease and related hospital admissions in valley residents. To better examine the relationship between plant-associated changes in ambient particulate matter (PM) and respiratory health effects, we obtained TSP filters originally collected near the steel mill during the winter of 1986 (before closure), 1987 (during closure), and 1988 (after plant reopening). PM subcomponents were water-extracted from these filters and Sprague-Dawley rats were intratracheally instilled with equivalent masses of extract. Data indicated that 24h later, rats exposed to 1986 or 1988 extracts developed significant pulmonary injury and neutrophilic inflammation. Additionally, 50% of rats exposed to 1986 or 1988 extracts had increased airway responsiveness to acetylcholine, compared to 17% and 25% of rats exposed to saline or the 1987 extract, respectively. By 96h, these effects were largely resolved except for increases in lung lavage fluid neutrophils and lymphocytes in 1986-extract-exposed rats. Analogous effects were observed with lung histologic assessment. Extract analysis using ICP-MS demonstrated that in all three extracts nearly 70% of the mass appeared to be sodium-based salts derived from the glass filter matrix. Interestingly, relative to the 1987 extract, the 1986/1988 extracts contained more sulfate, cationic salts (i.e., calcium, potassium, and magnesium), and certain metals (i.e., copper, zinc, iron, lead, strontium, arsenic, manganese, and nickel). Although total metal content was 1% of the extracts by mass, the relatively greater quantity detected in the 1986 and 1988 extracts suggests that metals may be important determinants of the pulmonary toxicity observed. In conclusion, the pulmonary effects induced by exposure of rats to water-based extracts of local ambient PM filters were in good accord with the cross-sectional epidemiological reports of adverse respiratory health effects in Utah Valley residents.