S-Sulfonates in Human Plasma following Inhalation of Sulfur Dioxide

Plasma S-sulfonate was measured in human subjects exposed continuously under controlled conditions to sulfur dioxide for periods up to 120 hours. Subjects were exposed to chamber SO2 concentrations of 0.3, 1.0, 3.0, 4.2, and 6.0 ppm and to a control exposure with ambient air. Plasma levels of S-sulfonate showed positive correlation with atmospheric sulfur dioxide; the regression line fitted to all 80 data points determined in this experiment resulted in a highly significant correlation (correlation coefficient = 0.61, p < 0.001). The slope of the regression line was an estimated increase of 1.1 ± 0.16 (S.E.) nmoles of S-sulfonate per milliliter of plasma for each ppm increment in chamber sulfur dioxide concentration.