Indoor Air Pollution
Indoor air quality (IAQ) refers to the physical, chemical, and biological characteristics of air in the indoor environment within a building or an institution or commercial facility. These characteristics can be influenced by many factors, even though these buildings or facilities do not have industrial processes and operations found in factories and plants. (Regional workshop on Household Energy and Health, 2-3 May, 2002, New Delhi, India)
Factors that influence IAQ include the following.
- In adequate supply of outside air.
- Contamination arising from sources within the building (e.g., combustion products including carbon monoxide and smoke; volatile organic compounds from building materials, fabric furnishings, carpet, adhesives, fresh paint, new panelling, and cleaning products; ozone from office equipment).
- Contamination from outside the building (e.g., ozone, carbon monoxide, and particulate matter through air intakes, infiltration, open doors, and windows.
- Microbial contamination of ventilation systems or building interiors.
The main purpose of the household energy system is to meet the energy needs of the household. In general, these needs may be classed in 6 categories: warmth, heat, light, mechanical power, communication and comfort. It is in the combustion of fuel to meet these needs that source emissions are generated, and the chain from emissions to eventual health effects begins.
We can start by summarising a number of well-known facts about the mechanisms of exposure: the combustion of (cooking) fuels generates air pollution in the form of particulate matter and gases. The quantity of each pollutant released is dependant on the combustion conditions, and the pollutant emission rates vary strongly with time, and, depending on the stove geometry, with each other (Ballard-Tremeer & Jawurek 1996 and Ezzati et al 2000). The concentration of the pollutant in the air, measured on a mass per volume basis, depends on emission rate (the source adding the pollutant), and ventilation (the sink removing or distributing the pollutant). Depending on the ventilation conditions, concentrations will have both a temporal and spatial variation. Human exposure to the cocktail of pollutants is determined by the amount of pollutant experienced by the people exposed and the time spent exposed to this concentration. 'Dose' is the measure of the quantity of pollutant deposited in the body and depends on exposure as well as the pollutant characteristics (such as particle size) and rate of breathing. Field experience has shown that breathing rate can vary widely - cooks have been observed, for example, to blow vigorously on the fire during the preparation of a meal to keep the fire burning well or to change fire power (temperature) rapidly to meet cooking needs. The deep breaths required will have a large effect on dosage. The health effects depend, however, not only on dose, but also on the toxicity of the pollutant, and the individual response of the person's body to the pollutant.
Although health effects of IAP seem to be the most reviewed health impacts of indoor air pollution, lack of access has various impacts on health that seem to be less explored
- Webpage of Kirk R. Smith - contains an extensive list of publications on Indoor Air Pollution in the context of energy in developing countries.