Nicas M, Spear R C
Center for Occupational and Environmental Health, School of Public Health, University of California, Berkeley 94720.
Am Ind Hyg Assoc J. 1992 Jul;53(7):411-8. doi: 10.1080/15298669291359870.
The basic respirator equation states that the contaminant level inside a respirator (CI) is the product of the contaminant level outside the respirator (CO) and the decimal fraction penetration (P). On the basis of this relation, the authors present a probability model for the lognormal total distribution of CI levels among a respirator-wearing population; the model accounts for between-wearer and within-wearer variability in both CO levels and P values. The assumptions underlying the model are shown to be consistent with current knowledge about the variability in CO levels and P values. The model provides the basis for assessing the probability of overexposure to acute toxicants and to chronic toxicants among a respirator-wearing population.
