At present, priorities are determined by the availability of research methods
and facilities geared to selected kinds of research, the special interests of scientists,
political activists and the vendors of indoor ventilation systems. However,
priorities should be determined on the basis of a realistic appraisal of the
incidence and severity of disease attributable to poor indoor air quality. Lists
of priorities determined on this latter basis differ widely according to climate,
location and affluence. In wealthy Western countries with temperate climates,
exposure to the allergenic faeces of bed mites is the most serious and widespread
health problem. In cities in developing countries with hot climates, the
mixing of indoor air with outdoor air polluted by traffic and industrial fumes
is usually the most serious single problem. By contrast, in poor cold locations,
exposure to carbon monoxide and heating and cooking fumes in poorly ventilated
or wholly unventilated dwellings comes to the top of the problem list.
Further research on sick building syndrome, radon, formaldehyde, fibrous
dusts and environmental tobacco smoke merits little priority in relation to the
most serious indoor air quality problems found in developing countries.