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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 cleaning; control; deposition; penetration; resuspension; review; source; synthetic vitreous fiber; track-in; transport.
The presence of dust and fibers in the indoor environment is a problem if occupants complain about visually perceived dustiness or have subjective or objective symptoms attributed or attributable to dust or fibers. Several species of paniculate- or particle-borne chemicals for intended use, unintentional particle emissions, and particles of pet, pest or microbial origin are likely to cause health effects in nonindustrial indoor environments. For dust in general, a review of the literature up to August 2001 concluded that there was limited and inconclusive scientific evidence that mass or number concentrations are useful risk indicators for health effects in buildings. It follows that there was inadequate scientific evidence to establish health-based limits or guidelines for airborne paniculate mass or number concentration (1). The study did not attempt to identify causative agents (ie, whether health effects were due to low levels of ubiquitous allergens, toxins, or irritants or specific major components). Recent chamber tests (2-4) involving human exposure to office dust without major reactive compounds (5) have provided limited additional evidence.
Control of concentration levels
In the absence of scientifically based guidelnes for airborne dust concentrations, good practice would be to keep dust levels at...