Abstract

The goals of this project were to develop a strategy for the use of expired air in the biological monitoring of exposure to volatile solvents, collect further experimental data, and predict the effect of a number of exposure-related factors on solvent elimination in expired air.

Volunteers were exposed to the following seven solvents, representing a wide range of physical chemical and metabolic characteristics: toluene, xylene, trichloroethylene, 1,1,1-trichloroethane, acetone, methyl ethyl ketone, and methyl isobutyl ketone. Pharmacokinetic simulation and modelling was also performed, to extend the scope of the experimental results, help predict the influence of various factors on solvent effects, including elimination in expired air.

Elimination in expired air is directly proportional to the concentration of solvents in ambient air. The models correctly predicted the levels to which exposure should be lowered when the exposure period was lengthened from 8 hours to 12 hours, or when volunteers engaged in moderate physical exercise. The influence of variable levels of exposure throughout the day on biological indicators of exposure was also correctly predicted.