## 4 Discussion
Based on the IA group's information, attempts to solve the indoor air problems in several buildings had lasted more than a year. The IA group's evaluation of no IAQ problems in the premises often contradicted our building investigation results. One reason for these prolonged problem-solving processes may be that building-related problems or impurity sources have been unclear or building investigations incomplete. An earlier study also had similar findings [4]. Prolonged or unclear problem-solving processes may have increased health concerns and distrust of the problem-solvingprocess and influenced the IAQ-related experience of employees. Thus, careful decision-making procedures are important, especially when people feel threatened by IAQ-related risks [34]. The employees did not know the results of the assessment of the probability of abnormal IA exposure prior to responding to the IA questionnaires, which contributes to the reliability of the study. The differences between previous studies and our research results may result from differences in the building research methods. Many studies are based on observations of visible damage or indications of damage, and hidden damage has remained unclear [11]. Our study was very detailed, and we also investigated hidden damage, in addition other pollutant sources. Possible limitations of our research may be that our data concerned only a small number of buildings with no IAQ problems or impurities affecting IAQ, which may have affected data distribution. Due to this, we had no reliable comparison survey of damaged and nondamaged buildings or premises. The method for assessing the probability of abnormal IA exposure is very pragmatic and is always based on strong technical expertise in building technology and IAQ. In addition, the criteria for the probability of abnormal IA exposure recommend taking into account many impurity sources in a building, based on national instructions, regulations and limit values in the field of the built environment and IAQ. However, the assessment also involves a researcher's subjective view. OHS' information was collected at group-level, and as the results were analysed categorically, they may not have provided sufficiently accurate results. In addition, the questions concerning the psychosocial work environment were quite limited in the IA questionnaire. They covered qualitative and quantitative workload, opportunities to influence one's working conditions, and social support at work. Although these are essential factors in the light of the stress theory, they fail to provide a comprehensive picture of the psychosocial work environment. The questionnaire did not include, for instance, factors such as organizational changes and questions concerning leadership. The probability of abnormal IA exposure provides us with a holistic picture of the many factors affecting the IAQ of buildings and premises. In this case, the most urgent measures could have been identified more easily and holistically. Moreover, in the premises that needed the most urgent repairs, employee contact with OHS was increased, and the employees' perceived work environment-related symptoms indicated poor IAQ. On the other hand, in the premises in which no technical problems were found, the employees still perceived more work environment-related symptoms and stress than those reported in FOH's reference data. Thus, IAQ problems should always be analysed from many perspectives; (i) the building's technical condition, (ii) perceived IAQ and psychosocial work environment, (iii) OHS information, and (iv) measures for solving IAQ problems, which may all affect the experience of IAQ problems. Indoor air questionnaires can serve as a parallel method with technical investigations in the building.