The quality of indoor environment has become a matter of growing concern in many countries over the twenty years and even in our countries the interest in indoor air quality (IAQ) is still growing, but slowly. There is a lot of studies on different aspects of IAQ including some in CEEC, but there is still a lot of uncertainty in indoor air quality evaluation. Most of the common methods of risk assessment cannot be used from the different reasons. There are many results from different countries and different studies and according to research results, indoor climate in buildings varies a lot. So varies also human reactions. Only some symptoms are relatively clear in diagnostics (e.g. Building Related Illnesses) but mostly in practice we meet other than such problems. Therefore we should be very careful in evaluation of the health effect of indoor environment, especially in dose-response assessment.

        Key words: Indoor Air Quality (IAQ), health effects, adverse effect assessment