| Effects of Ambient Ozone Exposure on Mail Carriers' Peak Expiratory Flow Rates Chang-Chuan Chan and Tsung-Huan Wu Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan Abstract
The extent to which occupational exposure to ozone in ambient air can affect lung function remains unclear. We conducted a panel study in 43 mail carriers by measuring their peak expiratory flow rates (PEFRs) twice daily for 6 weeks in 2001. The daily exposure of each mail carrier to O3, particulate matter < 10 µm in aerodynamic diameter (PM10) , and nitrogen dioxide was estimated by one air monitoring station in the center of the mail carrier's delivery area. Hourly concentrations of air pollutants during their exposure periods were 6-96 ppb for O3, 11-249 µg/m3 for PM10, and 14-92 ppb for NO2. Linear mixed-effects models were used to estimate the association between air pollution exposures and PEFR after adjusting for subject's sex, age, and disease status and for temperature and humidity. We found that night PEFR and the deviation in night PEFR were significantly decreased in association with 8-hr O3 exposures with a lag 0-2 days and by daily maximum O3 exposures with a lag of 0-1 day in our multipollutant models. By contrast, neither PM10 nor NO2 was associated with a PEFR reduction. Daily 8-hr mean concentrations of O3 had greater reduction effects on PEFR than did daily maximum concentrations. For a 10-ppb increase in the 8-hr average O3 concentration, the night PEFR was decreased by 0.54% for a 0-day lag, 0.69% for a 1-day lag, and 0.52% for a 2-day lag. We found that an acute lung function reduction occurs in mail carriers exposed to O3 concentrations below current ambient air quality standards and occupational exposure limits. Key words: deviation, lung function, mail carrier, ozone exposure, peak expiratory flow rate. Environ Health Perspect 113:735-738 (2005) . doi:10.1289/ehp.7636 available via http://dx.doi.org/ [Online 14 March 2005]
Address correspondence to C.-C. Chan, Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Room 1447, 1st Section, No. 1 Ren-ai Rd., Taipei 100, Taiwan. Telephone/Fax: 886-2-2322-2362. E-mail: ccchan@ha.mc.ntu.edu.tw The authors declare they have no competing financial interests. Received 5 October 2004 ; accepted 14 March 2005.
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