In the absence of scientifically based guidelines for airborne dust concentrations, good practice calls for dust levels to be kept as low as practically achievable. To do so means reducing the sources. Once particles are introduced, there is only one way of removing them, through a combination of ventilation and surface cleaning. These removal processes, in combination with source emissions and material transport between indoor air and surface compartments, determine the net concentration of particles in the room air. Data on source emission and transport rates are presented in this paper. Such data provide useful background information for developing effective strategies for controlling particles in indoor air. Visually perceived cleanliness is one measure of indoor-air quality and is the subjective assessment of cleaning quality. Cleaning quality can be concisely defined and objectively assessed according to a Nordic standard on cleaning quality. An example of how to deal with complaints of irritation attributed to particles in the absence of concentration guidelines is presented for synthetic vitreous fibers.

Key terms cause; cleaning; control; deposition; dust; indoor environment; indoor environment problem; penetration; resuspension; review; source; synthetic vitreous fibers; track-in; transport