Dampness and mould over 20 years and new onset of respiratory symptoms, asthma and rhinitis.

Indoor dampness and mould exposure are associated with respiratory health, but there is limited evidence on long-term effects in adults. Indoor dampness and mould, and the onset of respiratory symptoms, asthma, and rhinitis, were studied in the Respiratory Health in Northern Europe (RHINE) cohort, in which 8407 adults participated in both the 20-year and 30-year follow-up (RHINE III and IV, respectively). Participants completed a questionnaire on indoor dampness and mould at home and at the workplace, and on respiratory health. In RHINE IV, the prevalence of dampness or mould exposure in the past 10 years was 28.6%, while 15.1% of participants reported a 20-year cumulative exposure. Home exposure of dampness or mould was linked to increased onset of nocturnal chest tightness (OR = 1.80), nocturnal breathlessness (OR = 1.76), productive cough (OR = 1.41), and allergic rhinitis (OR = 1.27) and work exposure of dampness or mould with increased onset of wheeze (OR = 1.58), nocturnal chest tightness (OR = 1.53), doctor-diagnosed asthma (OR = 1.68), and rhinitis (OR = 1.35). Combined home and work exposure showed stronger associations for nocturnal chest tightness (OR = 1.99), doctor-diagnosed asthma (OR = 1.90), and rhinitis (OR = 2.24). Cumulative 20-year exposure accentuated the association with respiratory symptoms. Long-term exposure to dampness or mould at home or at work increased the risk of developing respiratory symptoms, asthma, and rhinitis. Combined exposure at home and work, and a prolonged exposure period, may play a significant role in the development of adverse respiratory outcomes in adults.