Preventive measures and intervention on carpet removal and ventilation improvement in eleven schools.

An intervention study in eleven schools with approximately 1000 children age twelve to thirteen has been carried out in the period 1997 to 1999. Four schools with poor ventilation standard, three schools with carpets and four reference schools participated. In the schools with carpets, these have been removed and in the schools with poor ventilation systems, these have been upgraded to Norwegian standards for new buildings. A questionnaire was answered three times during a two-week period, asking how indoor environment-related symptoms were perceived. McNemars statistical analyses show that for some symptoms and environmental factors the interventions have been successful. A multiple linear regression carried out on the survey data from before intervention show that there are only few factors associated with the SBS building symptoms, and the variation in symptoms cannot be completely described from measured, observed or perceived variables.