Previous cross-sectional and prevalent case-control studies have suggested increased risk of asthma in adults related to dampness problems and molds in homes. We conducted a population-based incident case-control study to assess the effects of indoor dampness problems and molds at work and at home on development of asthma in adults. We recruited systematically all new cases of asthma during a 2.5-year study period (1997-2000) and randomly selected controls from a source population consisting of adults 21-63 years old living in the Pirkanmaa Hospital district, South Finland. The clinically diagnosed case series consisted of 521 adults with newly diagnosed asthma and the control series of 932 controls, after we excluded 76 (7.5%) controls with a history of asthma. In logistic regression analysis adjusting for confounders, the risk of asthma was related to the presence of visible mold and/or mold odor in the workplace (odds ratio, 1.54; 95% confidence interval, 1.01-2.32) but not to water damage or damp stains alone. We estimated the fraction of asthma attributable to workplace mold exposure to be 35.1% (95% confidence interval, 1.0-56.9%) among the exposed. Present results provide new evidence of the relation between workplace exposure to indoor molds and adult-onset asthma.

This study indicates for the first time that both cumulative lifetime and recent ETS exposures increase the risk of adult-onset asthma.

Studies on the effect of smoking on adulthood asthma have provided contradictory results. The current authors conducted a population-based incident casecontrol study to assess the effects of current and past smoking on the development of asthma in adults.During a 2.5 yr study period, all new asthma cases clinically diagnosed (n=521) and randomly selected controls (n=932) from a geographically defined district in southern Finland were recruited.The risk of developing asthma was significantly higher among current smokers with an adjusted odds ratio (OR) of 1.33 (95% confidence interval 1.00-1.77) and among ex-smokers with an adjusted OR 1.49 (1.12-1.97) compared with never-smokers. Among current smokers, the risk increased up to 14 cigarettes?day -1 , and a similar trend was observed in relation to cumulative smoking.In conclusion, the current results support the hypothesis that smoking causes asthma in adulthood.