Environmental tobacco smoke exposure and overtime work as risk factors forsick building syndrome in Japan

Sick building syndrome (SBS) is an increasingly common health problem for w orkers in modern office buildings. It is characterized by irritation of muc ous membranes and the skin and general malaise. The impact of environmental tobacco smoke (ETS) exposure and overtime work on these symptoms remains u nclear. The authors examined these relations using data from a 1998 cross-s ectional survey of 1,281 municipal employees who worked in a variety of bui ldings in a Japanese city. Logistic regression was used to estimate the odd s ratio for symptoms typical of SIBS while adjusting for potential confound ers. Among nonsmokers, the odds ratio for the association between study-def ined SIBS and 4 hours of ETS exposure per day was 2.7 (95% confidence inter val: 1.6, 4.8), and for most symptom categories, odds ratios increased with increasing hours of ETS exposure. Working overtime for 30 or more hours pe r month was also associated with SIBS symptoms, but the crude odds ratio of 3.0 for SBS (95% confidence interval: 1.8, 5.0) was reduced by 21% after a djustment for variables associated with overtime work and by 49% after furt her adjustment for perceived work overload. These results suggest that both ETS exposure and extensive amounts of overtime work contribute to the deve lopment of SIBS symptoms and that the association between overtime and SBS can be explained substantially by the work environment and personal lifesty le correlated with overtime.