Retention of inhaled sarin vapor and its effect on red blood cell cholinesterase activity in man.

Abstract

This study was conducted to determine whether retention and absorption of sarin vapor differ in (1) resting men breathing exclusively through the nose (2) or the mouth, and (3) in exercising men breathing exclusively through the mouth. Inhibition of red blood cell cholinesterase (R.B.C.‐ChE) activity was the criterion used to measure absorption. We found that the resting men retained approximately the same percentage of the vapor inhaled, but exercising men retained a significantly lower percentage. This does not mean that in an uncontrolled exposure sedentary people would receive a higher dose than active people. In fact, iust the opposite would be true because minute volume is much higher in exercising people and their total retained dose would be much higher. We also found that, regardless of route of inhalation (oral or nasal) or level of physical activity, inhibition of R.B.C.‐ChE activity was directly related to the retained dose of sarin.