RECENT ADVANCES IN MEASURING EXHALED BREATH AND ESTIMATING EXPOSURE AND BODY BURDEN FOR VOLATILE ORGANIC-COMPOUNDS (VOCS)

An improved portable breath measurement method has been developed that allows 1-min sampling times. The equipment has been successfully test ed in field and chamber studies. Results of these studies suggest that breath levels following known exposures are predictable and reproduci ble across a small number of volunteers. The residence times in the bo dy and the distribution in body compartments of several common air tox ics have been determined. A simple four-compartment linear model is ca pable of fitting the observed data. The main parameters of the model i nclude the fraction f of the parent compound exhaled under steady-stat e conditions and the residence times tau(i) in the tau(i)th compartmen t. The values of these parameters for several VOCs and for the four bo dy compartments (blood, vessel-rich tissues, vessel-poor tissues, and fat) are provided.