Symptoms, signs, perceptions, and objective measures were studied in university buildings. Two problem buildings with a history of dampness and complaints were compared with two control buildings. Health investigations among university staff were performed at the workplace (n = 173) including tear film stability [non-invasive break-up time (NIBUT) and self-reported break-up time (SBUT)], nasal patency (acoustic rhinometry), nasal lavage fluid analysis [NAL: eosinophil cationic protein (ECP), myeloperoxidase (MPO), lysozyme and albumin] and atopy by total serum IgE and IgE antibodies (Phadiatop). Exposure assessment included inspections, thermal and atmospheric climate at 56 points modelled for all work sites. Multiple regressions were applied, controlling for age and gender. Exposure differences between problem buildings and controls were small, and variations between rooms were greater. Workers in the problem buildings had more general and dermal symptoms, but not more objective signs than the others. Adjusted day NIBUT and SBUT increased at higher night air temperatures, with B (95% CI) 0.6 (0.04-1.2) and 1.3 (-0.02 to 2.5), respectively. Higher relative humidity at mean day air temperature <22.1 degrees C was associated with adjusted NIBUT and SBUT, with B (95% CI) 0.16 (0.03-0.29) and 0.37 (-0.01 to 0.75), respectively. Air velocity below recommended winter values and reduced relative humidity in the range of 15-30% were associated with dry air and too low temperature.
Practical implications: Thermal climate in university buildings may be associated with both perceptions and physiological signs. Reduced night time air temperature, increased difference in air temperature between day and night, and fast changes in air temperature might impair indoor environment. This may have implication for energy-saving policies. It might be difficult to identify the exposure behind, and find the reason why, some buildings are defined as 'problem buildings'.