Increased levels of bacterial markers and CO2 in occupied schools

The aim of this study was to test the following hypthesis : in schools, bacterial markers may be increased in indoor air because of the presence of children.Dust samples were collected from the school rooms when occupied but also when unoccupied during the week-end. Results have been analysed and the conclusion is that in unoccupied rooms the airborne dust is of environmental origin, whereas the increase level of dust in occupied rooms is due to the children presence.