Abstract
Despite the fact that modern humans spend almost 90 % of their time indoors, the indoor air quality does not attract the same attention as that of the ambient air. Standard monitoring networks record paradoxically only levels of air pollution outdoors while information on the indoor environment is scattered not systematically gathered and it is generally difficult even to find it.
The present study characterizes in a review manner the main types of indoor environment and lists the main sources of pollution as well as risk factors which can be encountered indoors. The text contains selected references offering the reader a basic possibility to find primary sources of information and in the case of deeper interest to use them for further study of this interesting field.