Discomforts and laboratory findings in workers exposed to sulfur dioxide.

In a broom manufacturing factory the authors performed microclimatic measurements, measurements of sulfur dioxide concentration and dust content. Workers (n = 190) were polled regarding discomforts characteristic of sulfur dioxide effects. Sulfates were determined in urine of 56 subjects, and methemoglobin and sulfhemoglobin were determined in blood. Sulfates were determined in 43 controls and methemoglobin and sulfhemoglobin were determined in 39 controls. Sulfur dioxide concentration in work environment ranged from 17.1 to 149.4 mg/m3 in winter and from 0 to 0.75 mg/m3 in summer. The exposed workers complained most often of coughing (94.2%), dyspnea (91.0%), burning in nose, eyes and throat (from 74.7 to 83.7%), substernal pain (75.3%), sore throat (74.7%), tearing (64.7%), etc. Sulfate concentrations were found to be statistically significantly higher (P less than 0.01) in urine of workers exposed to sulfur dioxide than in the controls. Methemoglobin concentrations were also significantly higher in blood of the exposed workers, whereas no difference was found in concentrations of sulfhemoglobin.