The relationship between indoor and outdoor concentration levels of particles in the absenceand in the presence of indoor sources has been attracting an increasing level of attention.Understanding of the relationship and the mechanisms driving it, as well as the ability toquantify it, are of importance for assessment of source contribution, assessment of humanexposure and for control and management of particles.
The most important indoor particle sources in the four single family homes studied were found to be cooking, cleaning and the movement of people. The sources contributed significantly to indoor concentration and to altered indoor particle size distributions. Air exchange rates ranged between 0.12 and 24.3 ach and impacted on indoor particle levels and size distributions.
Much publicity has been given to the potential health risks posed by buildings, particularly those with mechanical ventilation or air conditioning. There have been concerns over the possible effects of the vocs given off by the furnishings and finishes, of fungal spores shed from dirty ducting, of legionella distributed by wet cooling towers, of insufficient ventilation air, etc., etc. The list of concerns is a long one. But what about the effects on the building occupants of the air brought in from outside, the so-called 'fresh air'?
Recent concerns have been expressed with regard to emissions of glass fibers from heating, ventilation, and air conditioning (HV AC) systems. In this literature review, over 350 citations were found, of which 10 reported original measurements of glass fiber concentrations associated with the presence of fibrous glass duct lining or duct board, and two yielded sufficient data from which emission rates could be calculated.