An experiment was designed to determine whether the respiratory retention of sytrene vapor, as estimated from measurements of end-exhaled air, was the same during periods of both constant and fluctuating exposure.
Six human subjects were exposed to styrene inside an experimental chamber.
A computercontrolled system was used to generate time-varying air concentrations of styrene over 4-5 h in both multistep sequences of constant exposure (four subjects exposed to 15-99 ppm of styrene in 100-min steps) and fluctuating patterns representative of occupational exposures (two subjects exposed to mean concentrations of styrene of 50 ppm).
In the latter case, lognormally distributed exposures, which fit one of two first-order autoregressive models, were generated at intervals of 2.5 min.
It was found that the concentration of styrene in end-exhaled air was reduced by about half if the subject inhaled one to three breaths of clean air prior to sampling.
This suggests that significant amounts of styrene were desorbed from the lining of the lungs during the initial exhalation.
The retention of styrene vapor during constant exposures was 0.935 and was independent of the level.
During each of the two sets of fluctuating exposure the retention of sytrene was also constant and was independent of both the variance and the autocorrelation coefficient.
Mots-clés Pascal : Styrène, Inhalation, Exposition professionnelle, Homme, Relation dose réponse, Rétention, Poumon, Air expiré, Autocorrélation, Médecine travail, Chambre simulation, Appareil respiratoire, Solvant organique
Mots-clés Pascal anglais : Styrene, Inhalation, Occupational exposure, Human, Dose activity relation, Retention, Lung, Expired air, Autocorrelation, Occupational medicine, Simulation chamber, Respiratory system, Organic solvent
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 95-0244909
Code Inist : 002B03L06. Création : 09/06/1995.