Major changes in indoor airrelated symptoms, health worry, and views between 2018 and 2022 in Finland

Background Indoor air-related symptoms and health-worry are common in Finland, even though the levels of indoor air pollutants are mostly lower than elsewhere in Europe. To address these problems, the Finnish Indoor Air and Health Programme 2018-2028 was initiated. Changes in the population were monitored with repeated surveys. Methods Questionnaire surveys were conducted in two independent random samples of Finnish people aged 25-64 in 2018 and 2022, with 1797 and 1616 responses, respectively. Changes in the prevalence of symptoms and other factors were investigated using multivariate logistic regression. Findings on the prevalence of symptoms were replicated in two additional major national surveys. Results Several significant changes were observed. In 2018, 45.8% reported worry related to the health effects of indoor air, compared with 26.8% in 2022. Indoor air-related symptoms at work decreased from 21.3 to 16.2%, and more respondents deemed the indoor air at their workplace as good. Moderate to severe symptoms decreased from 10 to 8%. Smaller improvements were observed in knowledge about the health effects of indoor air. Changes tended to be stronger among women and among those with an academic degree, less trust in social media, and less severe symptoms. Conclusions Four years after the Finnish Indoor Air and Health Programme was initiated, several improvements occurred in the population in self-reported symptoms, perceived indoor air quality, health worry, and knowledge. Although it is impossible to disentangle the different causes for these changes by repeated surveys, it is likely that the programme has contributed to the positive developments observed.