Improving indoor air quality for poor families: a controlled experiment in Bangladesh
1World Bank--Research-DECRG/Ru, 1818 H Street NW, Washington, DC 20433, USA. sdasgupta@worldbank.org
Insights
Indoor air pollution from cooking fuels kills many children annually. Improving kitchen design and ventilation can significantly reduce exposure, especially when clean fuels are unavailable.
Area of Science:
- Environmental Health
- Public Health
- Indoor Air Quality
Background:
- Indoor air pollution (IAP) from burning biomass fuels causes millions of child deaths annually, particularly in South Asia and Africa.
- Biomass fuels are a major source of acute respiratory infections in developing countries, disproportionately affecting impoverished families.
Purpose of the Study:
- To investigate the impact of various factors on indoor air pollution levels.
- To assess the effectiveness of different fuels, construction materials, space configurations, cooking locations, and ventilation practices in mitigating IAP.
Main Methods:
- Controlled experiments were conducted in Bangladesh to analyze the effects of changing determinants of indoor air pollution.
- Data analysis focused on the rapid and complete transport of cooking area pollution into living spaces and the interaction between outdoor and indoor air pollution.
Main Results:
- Pollution from cooking areas quickly permeates living spaces.
- The choice of cooking fuel significantly impacts pollution levels, with biomass fuels being substantially dirtier than clean fuels like LPG and kerosene.
- Seasonal variations influence the relative severity of pollution from different biomass fuels and the optimal placement of cooking areas.
Conclusions:
- Permeable kitchen construction materials and proper ventilation can improve the indoor health environment when clean fuels are not feasible.
- Village-level interventions, including bulk purchasing of cleaner fuels, fuel-efficient stoves, peripheral cooking facilities, and improved ventilation stacks, can reduce IAP exposure.
- Effective public education on IAP risks and financial/technical assistance are crucial for implementing these health-improving measures.
Unlabelled:
The World Health Organization's 2004 Global and Regional Burden of Disease Report estimates that acute respiratory infections from indoor air pollution (pollution from burning wood, animal dung, and other bio-fuels) kill a million children annually in developing countries, inflicting a particularly heavy toll on poor families in South Asia and Africa. This paper reports on an experiment that studied the use of different fuels in conjunction with different combinations of construction materials, space configurations, cooking locations, and household ventilation practices (use of doors and windows) as potentially-important determinants of indoor air pollution. Results from controlled experiments in Bangladesh were analyzed to test whether changes in these determinants can have significant effects on indoor air pollution. Analysis of the data shows, for example, that pollution from the cooking area is transported into living spaces rapidly and completely. Furthermore, it is important to factor in the interaction between outdoor and indoor air pollution. Hence, the optimal cooking location should take 'seasonality' in account. Among fuels, seasonal conditions seem to affect the relative severity of pollution from wood, dung, and other biomass fuels. However, there is no ambiguity about their collective impact. All are far dirtier than clean (LPG and Kerosene) fuels. The analysis concludes that if cooking with clean fuels is not possible, then building the kitchen with permeable construction material and providing proper ventilation in cooking areas will yield a better indoor health environment.
Practical Implications:
Several village-level measures could significantly reduce IAP exposure in Bangladesh. All would require arrangements and the assert of male heads-of-household: negotiated bulk purchases of higher cost, cleaner fuels; purchase of more fuel-efficient stoves; peripheral location of cooking facilities; building the kitchen with permeable construction material; rotation of women in cooking roles, to reduce their exposure; and ventilation of smoke through a stack tall enough to disperse smoke over a relatively broad area. It is expected that village men and women will agree to these measures if they become convinced that IAP poses a serious risk to health, and their actions will significantly reduce the risk. The keys to success are effective public education about the sources and risks of IAP, and financial and technical assistance for changes in cooking arrangements.
