The effect of outdoor fungal spore concentrations on daily asthma severity.

The Effect of Outdoor Fungal Spore Concentrations on Daily Asthma Severity Ralph J. Delfino,1-2 Robert S. Zeiger,3'4 James M. Seltzer,3'5 Donald H. Street,6 Renee M Matteucci,1 Patrick R. Anderson,7 Petros Koutraki tGraduate School of Public Health, San Diego State University, San Diego, CA 92120 USA; 2Epidemiology Division, Department of Medicine, University of California, Irvine, CA 92717 USA; 3Department of Pediatrics, University of California, San Diego, CA 92103 USA; 4Department of Allergy, Southern California Permanente Medical Group, San Diego, CA 92111 USA; 5Clinical Research Institute, San Diego, CA 92131 USA; 6Bayer Corp., Allergy Products, Independence, OR 97351 USA; 7Environmental Chemistry Laboratory, Department of Environmental Health, Harvard University School of Public Health, Boston, MA 02115 USA panel of this paper and an additional panel from the fall of 1994 in Alpine; Liu et al. be d We eamined the describe prediction models and factors that y pa.t ,Td e nl -def neo Wsehexaic. es ..;. determine personal ozone exposure levels. The relationship between day-to-dy changes in as community air pollutants and aeroaliergens remai ef e yea if ot d~ and ciomined ep_osures a do were severity for X M So munity around the air inbersion base elevation (1,200 ); Dail ptom s respo ed asthma and particulate matter with a diameter <10 pm tide pelne (03 measure (t pg 12-hour day longtu reeonmontro protective, probbly doe to airE perods. Controlling iioni es duringhot, easted With for weather, all y out- hm7 7ymptom Although the importance of aeroallergens as triggers of asthma has been known for many years, particularly among asthmatics with demonstrable allergy (1), there is a lack of spe- cific information on the relationship between the level of exposure to specific aeroallergens and daily asthma status. However, there is a relative abundance of literature concerning the inflammatory responses to respiratory allergens among allergic asthmatics and the importance of anti-inflammatory therapy for the treatment of allergic asthma (2). The pre- sent study focuses on the impact of fungal spores on acute asthma severity, a topic that has not been well investigated. Several pub- lished studies addressing this issue involving individual asthmatics have not utilized time-series analytic techniques to detect acute exposure-response relationships (3-5); other studies have involved correlations between aggregated exposure and response data (6-9). Additionally, more research has been called for regarding the synergistic or antagonistic effects on asthma status caused by different ambient airborne contaminants including interactions between air pollutants and aeroal- lergens (10Q. The present study was designed to inves- tigate the potential interactive and indepen- dent effects of ozone (03) and outdoor aeroallergens (pollens and molds) on daily asthma severity. This was carried out using the panel study design, which is character- ized by longitudinal analyses of daily data for a panel of asthmatics, with each subject act- ing as his or her own control. This study was conducted in the small Southern California community of Alpine, California, over an 8- week period from 9 May through 3 July 1994. The time period was selected to maxi- mize both 03 and fungal spore exposures, and followed the peak spring pollen season for the area. This study represents the second in a series of epidemilogic studies utilizing personal passive 03 exposures. The first study found that 12 asthmatic children fol- lowed daily for 6 weeks showed notably stronger adverse effects from personal 03 than from outdoor stationary site 03 and found that outdoor airborne fungal spores adversely effected asthma symptom levels and as-needed bronchodilator use (11). In a recently published 03 modeling study, Liu et al. (12) utilized personal 03 data from the Materials and Methods Study population and allergy testing. The community targeted by this study was cho- sen in order to maximize the ability to iso- late the independent effect of 0 from par- ticulate air pollutants with which 03 is commonly found to be highly intercorrelat- ed. It is a semirural inland community of Southern California located around the small town of Alpine, whose residents live at or above the base of the air inversion zone (1,200 feet in elevation). It has had a permanent governmental air pollution monitoring site since 1981, with data show- ing high levels of transported and locally generated ozone but low levels of particu- late air pollution relative to more urbanized regions of the United States (13). The study protocols were approved by the institutional review boards of San Diego State University and the Southern California Permanente Medical Group. Informed written consent was obtained from all subjects and one of their legal guardians if they were under the age of 18 years. Recruitment of subjects was done by advertisements and through four schools in the Alpine area in addition to referrals from Address correspondence to R. J. Delfino, Epidemiology Division, Department of Medicine, College of Medicine, University of California, Irvine, CA 92697-7550 USA. The authors wish to thank M. Wolfson, P. Roberts, and C. Donoghue for the preparation and chemical analysis of ozone passive samplers and M. Hossain, D. White, and their staff for providing the stationary site 03 and weather data and for their assistance in siting the remaining stationary site monitors. We also thank F. Lurmann, P. Roberts, H. Margolis, and E. Avol for helping us obtain the PMIO data. We also appreciate the skilled efforts of our clinic coordinators K. Mostafa and L. Skific. Most of all we wish to thank our study participants for their diligent efforts. This project was supported by grant number ES06214 from the NIEHS. The contents of this paper are solely the responsibility of the authors and do not necessarily represent the official views of the NIEHS or the National Institutes of Health. Received 1 July 1996; accepted 19 February 1997. Volume 105, Number 6, June 1997 * Environmental Health Perspectives