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Research Article
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| Quantifying the Distribution of Inhalation Exposure in Human Populations: Distribution of Minute Volumes in Adults and Children
Jill A. J. Beals, Lisa M. Funk, Robert Fountain, and Richard Sedman Department of Mathematical Sciences, Portland State University, Portland Oregon 97207 USA Abstract
Assessments of inhalation exposure to environmental agents necessitate quantitative estimates of pulmonary ventilation rates. Estimating a range of exposures in a given population requires an understanding of the variability of ventilation rates in the population. Distributions of ventilation rates (Ve) were described based on the results of a large study where Ve were measured while subjects performed a variety of physical tasks. Three distinct ventilation levels were identified using cluster analyses of the mean Ve and then various activities were assigned to the three levels using a k-means procedure. Separate distributions were identified for the three Ve levels for adult males, adult females, and children. The variability of Ve was consistent with a lognormal distribution for all groups. An aggregate daily inhalation rate can be estimated based on the distributions of Ve. Key words: exposure, inhalation, minute volume, Monte Carlo, probabilistic, risk assessment. Environ Health Perspect 104:974-979 (1996)
Address correspondence to R. Fountain, Department of Mathematical Sciences, Portland State University, Portland, Oregon 97207 USA. The authors wish to express their appreciation for the assistance provided by Thomas Phillips, Susan Lum, Dorothy Shimer, and Peggy Jenkins of the California Air Resources Board. This paper was not subject to the review of the Oregon Department of Environmental Quality ; therefore, the material presented in no way represents the Department's rules, policies, or guidance. Received 4 January 1996 ; accepted 21 May 1996.
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