Exposure to air pollutants and air pollution problem are very high in indoor environments in developing countries. Smith has estimated that at the aggregate level (i.e., without accounting for particle size, chemical composition, and source), approximately 80% of total global exposure to airborne particulate matter occurs indoors in developing nations. Details of exposure for various household members, and the roles of both pollution and behavior (e.g., location with respect to stove and activities), have been studied and evaluated using new tools and technology.
Biomass smoke and drying biomass are very episodic, with peaks occurring when fuel is added or moved, the stove is lit, cooking pots are placed on or removed from the fire, or food is stirred. These are also the times that those household members who cook are closest to the fire (Fig. 4). When these patterns of exposure, which incorporate both pollution and behavior, are accounted for, it can be seen that those household members who take part in cooking or are near the cooking area (mostly women and children) are exposed to pollution levels that are tens of times higher than those in even the most polluted cities in the world (Fig. bellow). Further, a substantial portion of this exposure occurs during short peak periods when emissions are highest and the cook is closest to the fire (referred to as high-intensity exposure in Fig. bellow).
Of all indoor air issues, sick building syndrome (SBS) has probably been the subject of most interest and study. It is a poorly defined syndrome that is described as involving a ‘‘building in which complaints of ill health (usually 420% of occupants) are more common than may be expected’’ and has been formally recognized as a disease by the World Health Organization (WHO) since 1986. SBS concerns are largely workplace based and relate to the health of individual workers and the productivity of the organizations employing them. A clear distinction can be made with building-related illnesses (BRIs), which are clinically diagnosed diseases such as humidifier fever or Legionnaires’ disease, and are not considered to be SBS.
SBS is a relatively recent phenomenon; its incidence grew in the 1970s with the advent of more thermally energy efficient buildings, brought about by the 1973–1974 energy crisis. It is most common in new and recently refurbished buildings that contain complex heating, ventilation, and air-conditioning (HVAC vents) units, although it can be found in naturally ventilated buildings. The common features of SBS buildings are that they are airtight, warm (isothermal), energy-efficient buildings with forced ventilation and internally there are often a lot of textile coverings and soft furnishings. However, the symptoms of sick building syndrome cannot usually be traced to specific pollutants or sources within the building.
