The Örebro Model

When complaints regarding indoor air quality in buildings occur, it is sometimes easy to find an explanation if the ventilation is completely out of order or if obvious water damage and growth of mould are found. In general, however, the situation is much less clear, and besides unsatisfactory ventilation, low-level emissions from building materials or micro­biological growth can be to blame. Large technical surveys with chemical and microbiological measure­ments at this stage seldom give results on which remedial action can be based. Nor will clinical examination of the occupants or blood samples prove conclusive, mainly because methods for obtaining objective and relevant descriptions of the health effects are not yet available.

Systematic investigations and the collection of structured information from the occupants, will generally provide a basis on which to make the necessary complementary technical measurements of the building and to determine effective remedial action. This strategy was presented in a WHO document published in the early 1980s and has since been adopted as the method of choice in the Nordic countries (WHO, 1983). The illustration of the Örebro Model is seen below, indicating the basic idea of conducting an overview of environment factors before performing more advanced chemical or microbiological measurements – if necessary. However, it must be stressed that most indoor climate problems can be solved without these costly measurements.

One important part of this strategy is to describe the occupant`s experiences and perceptions of the indoor air using valid and reliable methodological instruments. The MM questionnaires were developed to fulfill this goal. The primary intention of the basic MM questionnaire was to create a simple and short questionnaire with valid, clear and reliable questions, useful in practical situations (see further information referring to “The MM Questionnaires”).

Environmental Medicine Kjell Andersson Örebro