Biochemical Changes in Humans upon Exposure to Sulfuric Acid Aersol and Exercise

Abstract

This study evaluated the effect of a single exposure to sulfuric acid aerosol on six human biochemical blood parameters. A total of 18 human subjects were exposed to ambient air for 4 hr on the first day of exposure and to 100 μg/m³ (0.033 μM) sulfuric acid aerosol (0.5 μm mean mass diameter) for 4 hr on the second day. A total of 17 human subjects were exposed for 4 hr to ambient air on both exposure days. On each exposure day, at 30 min and 90 min after exposure was initiated, all subjects engaged in a 15-min exercise period (walking 4 mph on a treadmill inclined at 10°). Six biochemical blood parameters were measured before and after exposure: glutathione, lysozyme, glutathione reductase, serum glutamic oxaloacetic acid transaminase, serum vitamin E, and 2, 3-diphosphoglyceric acid. The results indicate no significant effect of one 4-hr exposure of humans to 100 μg/m³ sulfuric acid aerosol. One significant post-exposure effect did occur—an increase in glutathione reductase—for both the control and acid-exposed group. It is concluded that at the levels studied, sulfuric acid aerosol is neutralized in the upper airways; consequently, no cellular damage is measurable.