Repeated Laboratory Ozone Exposures of Volunteer Los Angeles Residents: an Apparent Seasonal Variation in Response
- 1 October 1988
- journal article
- research article
- Published by SAGE Publications in Toxicology and Industrial Health
- Vol. 4 (4), 505-520
- https://doi.org/10.1177/074823378800400409
Abstract
This study was intended to help explain individual differences in susceptibility to irritant effects of ozone (O3), by determining whether prior ambient O3 exposures and/ or recent acute respiratory illness modified response to laboratory 03 exposures. Response was measured in terms of lung function changes and irritant symptoms. Initially, 59 adult volunteer Los Angeles area residents underwent screening exposures in spring, before the season of frequent high ambient O3 levels. Unusually responsive and nonresponsive individuals (N = 12 and 13 respectively) underwentfollowup exposures in autumn (late in the high-O3 season) and in winter (low-O3 season). All exposures were to 0.18 ppm O3 for 2 hr with intermittent heavy exercise at 31° C and 35% relative humidity. Nonresponders tended to remain nonresponsive throughout. In fall, responders had lost much of their reactivity, as if they had "adapted" to summer ambient 03 exposures. They did not regain reactivity by winter. Clinical laboratory findings suggestive of acute respiratory illness did not appear to correlate with O3 response. Eight responders and 9 nonresponders underwent another followup exposure in spring, about 1 yr after screening. By that time most responders had regained their reactivity; individual function changes were significantly correlated with changes 1 yr earlier. These results suggest that response to O3 is a persistent individual characteristic, but can be modified by repeated ambient exposures.Keywords
This publication has 9 references indexed in Scilit:
- Replicated Dose-Response Study of Sulfur Dioxide Effects in Normal, Atopic, and Asthmatic VolunteersAmerican Review of Respiratory Disease, 1987
- A Dose-Response Study of Healthy, Heavily Exercising Men Exposed To Ozone At Concentrations Near the Ambient Air Quality StandardToxicology and Industrial Health, 1986
- Collection and Analysis of Symptom Data in Clinical Air Pollution StudiesPublished by ASTM International ,1985
- Assessing health effects of air pollutionEnvironmental Science & Technology, 1984
- Duration of pulmonary function adaptation to ozone in humansAihaj Journal, 1982
- Persistence of Adaptation to Ozone in Volunteers Exposed Repeatedly for Six Weeks1-3American Review of Respiratory Disease, 1982
- A Movable Laboratory for Controlled Clinical Studies of Air Pollution ExposureJournal of the Air Pollution Control Association, 1979
- Studies in adaption to ambient oxidant air pollution: effects of ozone exposure in Los Angeles residents vs. new arrivals.Environmental Health Perspectives, 1976
- Experimental Studies on Human Health Effects of Air PollutantsArchives of environmental health, 1975