Abstract

Decrease in pulmonary function parameters (mostly in obstructive pattern) was shown to occur in workers exposed to high concentrations of sulfur dioxide (SO2) during the process of apricot sulfurization. Since the mechanism by which inhaled SO2induce bronchoconstriction is still unclear, the effects of SO2 exposure on serum TNF-a, IL-1b, IL-6, IL-8, nitrite and nitrate levels are investigated in order to help the understanding of the mechanism of SO2-induced bronchoconstriction.

Serum samples were obtained from 40 volunteer workers after an hour of exposure to SO2 (mean level: 322.32 ± 219.65 ppm), and from 23 healthy controls without a history of exposure to this irritant gas. The measured serum levels of TNF-a, IL-1b, IL-6, IL-8, direct nitrite, total nitrite and nitrate levels were found to be significantly (p<0.0001) increased in the workers' group compared to the controls. The mean serum levels of TNF-a, IL-1b, IL-6, IL-8, direct nitrite, total nitrite and nitrate were 430.60 ± 397.03 pg/ml, 436.67 ± 316.31 pg/ml, 752.11 ± 394.95 pg/ml, 262.12 ± 287.99 pg/ml, 7.75 ± 3.34 mmol/L, 115.72 ± 48.78 mmol/L and 107.97 ± 46.19 mmol/L in the workers; while they were 9.83 ± 3.12 pg/ml, <5 pg/ml, 7.49 ± 1.27 pg/ml, 9.38±1.99 pg/ml, 2.17 ± 0.77 mmol/L, 59.91 ± 7.56 mmol/L and 57.74 ± 7.20 mmol/L in the controls, respectively. These results show that an increase in serum TNF-a, IL-1b, IL-6, IL-8 and nitric oxide levels may be effective in the generation of SO2-induced bronchoconstriction.