THE SOUTH KARELIA AIR-POLLUTION STUDY - EFFECTS OF LOW-LEVEL EXPOSURETO MALODOROUS SULFUR-COMPOUNDS ON SYMPTOMS

Exposure to very low levels of ambient-air malodorous sulfur compounds and their effect on eye irritation, respiratory-tract symptoms, and c entral nervous system symptoms in adults were assessed. A cross-sectio nal self-administered questionnaire (response rate = 77%) was distribu ted during March and April 1992 to adults (n = 336) who lived in a nei ghborhood that contained a pulp mill and in a nonpolluted reference co mmunity (n = 380). In the exposed community, the measured annual mean concentrations of total reduced sulfur compounds and sulfur dioxide me asured in two stations were 2 to 3 mu g/m(3) and 1 mu g/m(3), respecti vely. In the reference community, the annual mean concentration of sul fur dioxide was 1 mu g/m(3). The residents of the community near the p ulp mill reported an excess of cough, respiratory infections, and head ache during the previous 4 wk, as well as during the preceding 12 mo. The relative risk for headache was increased significantly in the expo sed community, compared with the reference area: the adjusted odds rat io (aOR) was 1.83 (95% confidence interval [95% CI] = 1.06-3.15) durin g the previous 4 wk and 1.70 (95% CI = 1.05-2.73) during the preceding 12 mo. The relative risk for cough was also increased during the prec eding 12 mo (aOR = 1.64, 95% CI = 1.01-2.64). These results indicated that adverse health effects of malodorous sulfur compounds occur at lo wer concentrations than reported previously.