|Boiling Point No. 44 - Linking Household Energy with other Development Objectives (ITDG - ITDG, 2000, 44 p.)|
by Dr Nigel Bruce * Senior lecturer in Public Health, Department of Public Health, Whelan Building, Quadrangle, University of Liverpool, Liverpool L69 3GB. Tel: +44 (0)151 794 5582 Fax: +44 (0)151 794 5588; Email: [email protected].
Dr Alison Doig, Intermediate Technology Development Group, Schumacher Centre for Technology and Development, Bourton Hall, Bourton on Dunsmore, Rugby, Warwicks CV23 9QZ Email: [email protected]
*to whom correspondence should be addressed
Santt rgie domestique: la nssit'amorer les liens entre la recherche et le dloppement.
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Around two-thirds of all households in the developing countries still rely primarily on unprocessed biomass fuels (wood, dung, crop residues) for their daily cooking and heating needs (WRI 1998). In many of these households, the fuel is burned indoors on open fires or poorly functioning stoves, often with no chimney. The World Health Organisation (WHO) has recently argued that by far the greatest global burden of air pollution exposure occurs, not outdoors in the cities of the developed world, but indoors in poor rural communities (WHO 1997).
The health problems associated with household energy can usefully be thought about under the following three headings:
Fuel production and the environment
· Land use (which also has economic implications, with indirect health effects)
· Erosion, and effects on water supply, etc.
· Energy, and natural resource use, for example associated with charcoal production.
Fuel collection and supply
· The time taken to collect wood has an opportunity cost mainly for women and children in terms of education, economic activity, child care, etc.
· Danger to women in current and past war zones, e.g. from land mines.
· Physical effects of carrying large quantities of fuel wood, etc., again mainly involving women.
· Effects of smoke exposure, including acute lower respiratory infections (ALRI), chronic obstructive lung disease (COLD), carbon monoxide poisoning (mainly from charcoal, and coal use), lung cancer (from coal use), low birth weight, and tuberculosis. Eye problems are also frequently reported.
· Burns (open fires, kerosene), poisoning (eg from children drinking kerosene stored in soft drink bottles).
· Wider environmental health effects relating to greenhouse gas production
The goal so far as smoke pollution is concerned must be to reduce exposure sufficiently to have a useful impact on key health outcomes. For many poor rural and urban communities this may present a considerable challenge.
Practical issues in reducing exposure to bio-fuel smoke
The drive for fuel conservation
Over the last 20-30 years, the major goal of projects aimed at improving the household environment has been to substitute traditional open fires with more fuel-efficient stoves. An example of this type of activity is the ITDG Upesi stove project in Kenya (Figure 1), which aimed to achieve widespread introduction of an improved ceramic wood stove.
Figure 1: The Upesi Stove, Kenya
When compared with open fires, these stoves have been shown to use about 40% less firewood, and reduce carbon monoxide levels in the kitchens by nearly 30% (which is indicative of a reduction in other components of air pollution, including particulates). A key element of the success of the project has been the training of the producers, sellers and promoters of the stoves (most of whom are local women), in effective dissemination techniques. Many of the households with these improved stoves have reported that:
· the kitchens are cleaner;
· the children's safety from domestic fires/accidents have been improved; and
· there is considerable saving in the use of fuel wood.
However, with no flue and few other ways of venting smoke from the home, any reduction in exposure is due mainly to improvements in efficiency and the consequent reduction in cooking times.
Reducing exposure while meeting household needs
Experience from stove development work has shown that substantially reducing exposure levels, while at the same time preserving or improving fuel efficiency, is a technically demanding task. Many so-called improved stoves may yield one benefit, but this is often achieved at the expense of other aspects.
Identifying improved stoves that perform well across all relevant criteria is therefore important. Work carried out by WHO in the western highlands of Guatemala has included some detailed studies of a locally produced chimney stove known as the plancha (Figure 2). Two studies comparing the plancha with the traditional open fire and with LPG have been completed [Naeher 95, Boy (in press)], and have shown:
· In this rural setting, the plancha achieves lower levels of kitchen particulate (PM2.5) pollution than either the open fire or LPG (gas) stove. Many rural households using gas usually continue to use open fires for some tasks.
· Fuel efficiency of the plancha typically used in this area was little better than the open fire. With combustion chamber modifications however, considerable efficiency savings can be made.
· Many plancha stoves in this community are in poor condition, hence reducing the potential health benefits.
Figure 2: The Plancha Stove, Guatemala
One conclusion from these studies is that well designed, good quality stoves are both acceptable and effective, and (in some settings at least) perhaps a more appropriate medium term policy goal than lower cost, less durable devices. Maintaining stoves in good condition remains a priority issue for development.
Reducing exposure in more demanding environments
Substantial numbers of households in Asia, Africa and the Americas live in cold environments (some extremely cold), and the demands on the devices used to provide household energy are that much greater. An example of this situation is to be found in Ladakh in Northern India. Open fires are used, and around the capital Leh, many households have stoves with metal flues. Winters are extremely cold, and women and young children spend many hours each day indoors. The condition of the stoves and flues, which typically leak good deal, means that homes are very polluted. Ventilation is reduced to a minimum, and embers are raked out on a hearth to assist with space heating.
In settings such as these, the open fire or stove must provide the means to cook, to heat the home, provide light, as well as being a social focus for members of the household who may need to spend long periods indoors. It will not be easy to bring about substantial reductions in exposure in circumstances such as these where fuel is scarce and efficiency vital, alternatives to bio-mass are limited, and where poverty is widespread.
· Over the last 20-30 years, concern about fuel efficiency, rather than exposure reduction, has driven much of the effort in household energy and stoves.
· Fuel efficiency may be gained by improvements in combustion and heat transfer to cooking vessels, but often with only modest reduction in exposure to indoor air pollution.
· It is quite possible for stoves with flues, while reducing air pollution, to reduce fuel efficiency, space heating and available light when compared to traditional open fires.
· A broad perspective of the health and environmental effects of household energy use must be taken.
· Household energy serves many purposes in all homes, but the demands on fires and stoves are particularly great in high altitude, cold areas of the world.
· Householders (especially women), communities and producers must be involved in assessing, developing, producing and disseminating household energy interventions if these are to effective and sustainable.
Key information requirements in the field of indoor air pollution, household energy, and health
· Determination of the level of household smoke reduction required to have a worthwhile impact on key health outcomes such as childhood pneumonia.
· Evaluation of the cost-effectiveness of interventions, in a variety of settings.
Interventions to reduce smoke exposure
The following list illustrates the broad range of interventions that can contribute to reducing indoor air pollution exposure. In any given setting it is likely that a combination could be considered, but local circumstances should determine what is appropriate.
· Smoke removal - Simple hoods to remove smoke, flues attached to stoves, and chimneys.
· Housing design - Changes to kitchen design to increase ventilation and control the distribution of pollution. Chimneys or flues should be considered a part of house design and construction.
· Fuels - Methods of cleaning up existing fuels, for example biogas and other 'clean' bio-mass fuel products, or promoting more fuel-switching to alternatives such as LPG (bottled gas) or electricity.
· Improved stoves - Stove development to reduce emissions, through better combustion and/or more efficient heat transfer.
· Promoting awareness of long-term health effects on the part of users. This may lead to people finding their own ways of minimising exposure through better management of kitchen tasks, etc.
· Infant protection - Keeping children away from smoke will benefit their health, although issues of supervision and safety must be considered.
Policy level interventions
· Fuel pricing - To encourage the use of cleaner fuels.
· Other forms of financial assistance and development - subsidising initial cost of stoves, local micro-credit facilities for durable higher quality devices, linking household energy initiatives to income generation opportunities (eg through nursery development), etc.
· Training - to develop skills and expertise for more widespread technical development of stoves, for improved kitchen and housing design, and better education about risks to health.
What factors can help bring about change in policy?
Greater awareness of risk to health
The health risks associated with household energy, especially the exposure of women and young children to indoor air pollution, should be seen as a priority issue on the policy agenda. It is important to emphasise the potential health gains that can be achieved by reducing exposure, for the majority of households in the developing world, in both rural and urban settings.
What information is needed?
Research has an important part to play in providing the kinds of information needed to advocate for a stronger policy response, to develop and test more effective interventions and monitor progress. These research needs are summarised below:
By how much does exposure need to be reduced?
This apparently simple question has important consequences for research and policy, for example with the primary prevention of childhood pneumonia.
Pneumonia, the most common type of acute lower respiratory infection (ALRI), remains the single most important cause of death world-wide among children under 5 years of age. The risk of dying from ALRI is highest in the first year of life, and especially in the first six months.
However, if instead of asking whether smoke causes pneumonia, we turn the question round and ask, 'how much will feasible reductions in smoke exposure benefit children's health?', then for many of the world's poorest populations we are faced with considerable uncertainty. We have very little idea whether, say, halving pollution levels (as may be achieved by substituting an open fire with a fairly typical 'improved' stove) would reduce any of the major health problems associated with smoke exposure. It may well be that much more substantial reductions are required to achieve worthwhile improvements in health. The importance of this question is emphasised by the fact that, in practice, it has been very difficult to achieve large reductions in pollution levels - particularly in poor rural communities. The best way to answer this issue is to study directly the health benefits that result from measured reductions in exposure of children. Although studies of this type will be complex and expensive because of the need to measure health outcomes (such as the incidence of pneumonia) the findings would be very valuable and provide momentum for development work in the household energy field and support efforts to bring about really substantial improvements in the living conditions of the poorest people.
Table 1: Summary of types of study needed to ensure efficient coverage of all key research issues within a framework of demonstration projects.
Type of study
Studies on health effects of indoor air pollution, and the benefits of health of reducing exposure
· Strengthen evidence for links
between indoor air pollution and health.
Studies of improvement in technical aspects of stove performance and pollution (eg stove design, hoods, chimneys, etc).
· Fuel efficiency for various
tasks, and over time.
Studies of integrated, approaches to achieving sustainable improvements in household energy use.
· Identify integrated models for
achieving sustainable change.
Opportunities for linking research and development activities
Research and development work should not be seen as separate, unrelated activities. Better links can help promote a two-way exchange - ensuring the relevance of research to development needs and priorities, as well as helping to ensure that new knowledge derived from research is put into practice. Table 1 lists, for three broad types of study, examples of the kinds of objectives which can be addressed if a more integrated approach is taken to research and development.
A proposal for action through co-ordinated demonstration projects
There is a pressing need for those working in the field of health and household energy to raise the profile of this serious environmental health problem, and to encourage practical approaches to achieving effective change. This could be achieved by developing a co-ordinated programme of research and development, to strengthen the available scientific evidence on health effects, to promote the development and evaluation of cost-effective, sustainable interventions, and to monitor progress.
Better integration of this research and development work should be a theme which runs throughout these activities. One practical way to move this forward would be through establishing a co-ordinated set of demonstration projects in a range of settings, developing and evaluating locally appropriate interventions with well - standardised methods, and ensuring wide dissemination of the experience gained. Proposals for this are under development, and anyone interested in taking part is encouraged to contact the author.
Nigel Bruce trained in medicine and public health, and is involved in research and policy work on environment, health and development. He is a temporary consultant with the WHO, co-ordinating work on the prevention of respiratory diseases and other forms of ill-health through the improvement of household environments.
As Energy Specialist with Intermediate Technology, Alison Doig is manager and researcher for a number of international projects on small-scale energy systems
1. Bruce N et al. (1998) Quantifying the effect of indoor biofuel air pollution on respiratory health in observational studies: the role of confounding factors among women in highland Guatemala. International journal of Epidemiology Int J Epidemiol 1998; 27: 454-458.
2. Environmental Health Project. Indicators for programs to prevent diarrheal disease, malaria, and acute respiratory infections. Activity Report No 46 1997. EHP, Arlington VA.
3. WHO. Health and Environment in Sustainable Development. WHO/EHG/97.8 World Health Organisation, Geneva 1997
4. World Resources Institute (WRI), UNEP, UNDP, World Bank (1998). 1998-99 World Resources: a guide to the global environment. Oxford University Press.
5. Naeher L, Leaderer B, Smith K, et al. Indoor, outdoor and personal carbon monoxide and particulate levels in Quetzaltenango, Guatemala: characterisation of traditional, improved, and gas stoves in three test homes. WHO/CHD, Geneva 1996.
6. Boy E, Bruce N, Smith K, Hernandez R. Fuel efficiency of an improved wood-burning stove in rural Guatemala: implications for health, environment and development. Energy for Sustainable Development (in press).
Another useful contact for information on the health impacts of smoke is the USAID-Environmental Health Programme: contact Dan Campbell at [email protected]