Household air pollution

Overview

Three billion people rely on biomass for their source of domestic cooking fuel resulting in a health crisis in developing nations that is little known to those in the developed world – indoor air pollution (IAP). Because of cooking that occurs indoors in environments that lack proper ventilation, millions of primarily poor women and children across the globe face serious health risks from the use of dangerous biomass fuels such as wood, charcoal, dung, and crop residue. Conservative estimates “show that in 2000, between 1.5 and 2 million deaths were attributed to” exposure to IAP. Estimates further suggest “approximately 80% of total global exposure to airborne particulate matter occurs indoors in developing nations”. Even though the rate of dependence on biomass fuel is declining, this dwindling resource will not keep up with population growth which could ultimately put environments at even greater risk. In Kenya, efforts are currently being made to address the overall health risks to rural women and children.

Health implications

Rural Kenya has been the site of various applied research projects to determine the intensity of emissions that commonly occur from use of biomass fuels, particularly wood, dung, and crop residue. Smoke is the result of the incomplete combustion of solid fuel which women and children are exposed to up to seven hours each day in closed environments. These emissions will vary from day to day, season to season and amount of airflow within the residence. Exposure in poor homes far exceeds accepted safety levels by as much as one hundred times over. Because many Kenyan women utilize a three-stone fire, the worst offender, one kilogram of burning wood produces tiny particles of soot which can clog and irritate the bronchial pathways. The smoke also contains various poisonous gases such as aldehydes, benzene, and carbon monoxide. Exposure to IAP from combustion of solid fuels “has been implicated, with varying degrees of evidence, as a causal agent of several diseases…”. Acute lower respiratory infections (ALRI) and chronic obstructive pulmonary disease (COPD) are the leading causes of disease and death from exposure to smoke. Cataracts and blindness, lung cancer, tuberculosis, premature births and low birth weight are also suspected of being caused by IAP.

Women and primarily girls spend excess time each day in collecting fuel-wood in Kenya which exposes them to even further hazards including vulnerability to rape and also fractures from the weight of carrying heavy loads. This time could be spent in more productive ways such as attending school or income production. The use of biomass coupled with inefficient cooking apparatus leads to a web of social and environmental concerns which directly links to the United Nations Millennium Development Goals.

Interventions

Early interventions

Unfortunately, finding an affordable solution to address the many effects of IAP – improving combustion, reducing smoke exposure, improving safety and reducing labor, reducing fuel costs, and addressing sustainability – is complex and in need of continual improvement. Efforts to improve cook stoves in the past, beginning in the 1950’s, were primarily aimed at minimizing deforestation with no concern for IAP, though the effectiveness of these efforts to save firewood is debatable. Various attempts had various outcomes. For example, some improved stove designs in Kenya significantly reduced particulate emissions but produced higher CO2 and SO2 emissions. Flues to remove smoke were difficult to design and were fragile.

Improved Success

Current improved interventions however, include smoke hoods which operate in much the same manner as flues, to extract smoke, but are found to reduce levels of IAP more effectively than homes that relied solely on windows for ventilation. Some features of newly improved stoves include a chimney, enclosing the fire to retain heat, designing a pot holder to maximize heat transfer, dampers to control air flow, a ceramic insert to reduce heat loss, and multi-pot systems to allow for cooking multiple dishes.

Stoves are “now known to be one of the least-cost means to achieve…” the combined objective of reducing the health burden of IAP and in some areas reducing environmental stress from biomass harvesting. Some success in installation of interventions, including improved cook stoves, has been achieved primarily due to an interdisciplinary approach which includes multiple stakeholders. These projects have discovered that key socio-economic issues must be addressed to ensure the success of intervention programs. A multitude of complex issues indicate improved stoves are not merely a tool to save fuel.

Kenya Smoke and Health Project

The following information represents one successful intervention known as the Kenya Smoke and Health Project (1998-2001) which involved fifty rural households in two separate regions, Kajiado and West Kenya. These areas were chosen due to different climate, geographic, and cultural implications. Community participation was the primary focus for this project and as a result, those involved indicated the results far exceeded their expectations. Local women’s groups and, in the case of the project in West Kenya, men were actively involved. By involving the end-users the project resulted in more widespread acceptance and created the further benefit of providing local income.

Three key interventions were discussed and disseminated; ventilation by enlarging windows or opening eaves spaces, adding smoke hoods over the cooking area, or the option of installing an improved cook stove such as the Upesi stove. Smoke hoods are free-standing units that act like flues or chimneys in their effort to draw smoke out of the dwelling. They can be used over traditional open fires and this study showed they contribute to considerably lower levels of IAP. The smoke hood models were made with hard manila paper and then transferred to heavy-gauge galvanized sheet metal and manufactured locally. This resulted in further employment opportunities for the artisans who were trained by the project. The Upesi stove, made of clay and kiln-fired, was developed by Practical Action and East African partners to utilize wood and agricultural wastes. Because this stove was designed and adapted for local needs it produced several winning features. Not only does it cut the use of fuel-wood by approximately half, and reduce exposure to household smoke, it also empowers local women by creating employment as they are the ones who make and market the stoves. These women’s groups gain access to technical training in production and marketing and enjoy higher wage earnings and improved social status as a result of the introduction of this improved stove.

Benefits

Various benefits were realized including improved health; the most important aspect to each of the villagers involved. The people reported less internal heat allowing for better sleep, fewer headaches and fatigue, less eye irritation and coughs and dizziness. Safety increased due to the smoke hoods preventing goats and children from falling into the fire and less soot contamination was observed, along with snakes and rodents not entering the home. Windows allowed for the ability to view cattle from indoors, and also reduced kerosene needs due to improved interior lighting. Overall, the indoor environment improved greatly from various simple things that are taken for granted in modern western homes. Greater indoor light also allows for more income generation for women as they can do beadwork by the window when weather doesn’t allow for this work outdoors. Children also benefit from increased lighting for homework.

Interpersonal relationships developed among the women due to the project, and men better supported their wives initiative when the end result benefited them as well. While initial efforts to improve stoves were limited in success, current efforts are more successful due to the recognition that sustainable domestic energy resources are “central to reducing poverty and hunger, improving health…and improving the lives of women and children” . The optimal short-term goal in minimizing rural poverty is to provide inexpensive and acceptable solutions to the local people. Not only can stoves contribute to this intervention, but the use of cleaner fuels will also provide further benefits.

Environmental Impacts

Mortality and burden of disease are not the only detrimental effects from utilizing inefficient energy technology such as the combustion of biomass. Kenya’s pre-dominant energy source is biomass, providing “more than 90 per cent of rural household energy needs, about one-third in the form of charcoal and the rest from firewood”. Biomass energy sourced primarily from savannah woodlands includes firewood for inhabitants and charcoal for urban use. A small percentage is sourced by neighboring communities from closed and protected forests which are generally found in high population density areas. While biomass harvesting in sensitive areas is problematic, it is now determined “the great majority of biomass clearing is due to agricultural expansion and land conversion”. Approximately 38% of households “in high agro-ecological zones…” utilize agricultural waste due to frequent shortages of conventional fuel-wood. Use of crop residue and animal waste for domestic energy has detrimental results on soil quality and agricultural and livestock productivity. These materials are ultimately not available as soil conditioners, organic fertilizer, and livestock fodder, not to mention the “cumulative effects on national food security”. Most farmers are aware however, that when ag waste and dung are not used for energy, they are important elements to maintaining soil fertility. One of the most efficient ways to utilize crop waste and dung for domestic energy is to produce briquettes. The process of compacting the material into a donut shape creates more efficient combustion which contributes to reduced emission levels. A simple device allows for this process and it can be done locally.

Sustainable options

Large-scale combustion of biomass is only feasible if carried out in a sustainable manner. Concern is paramount for regeneration of renewable and sustainable fuel-wood sources if it is to continue to be available long-term. Attempts at sustainable solutions in Kenya could include developing energy crops (trees and shrubs) which would also provide additional income for farmers. This solution would benefit “cropland or rangeland prone to erosion and flooding…” as the root systems and leaf litter would enhance soil stability. Careful selection of regenerating varieties would be most sustainable because soil stability is not disrupted due to tilling and planting. Some people view this solution as a way to further exploit forests, but with proper management of forest resources this could be a viable solution.

Challenges

Widespread education and government funding will also be necessary to shift cultural practices to more sustainable energy use. For example, in an area in South Africa, even though access to electricity was available, many residents continued to use biomass fuels for cooking and heating due to cost of electrical appliances and cultural practices. Liquid petroleum gas (LPG), which has nearly 100% combustion and negligible emissions unfortunately is currently not cost effective. The use of solar power, such as solar cookers, has drawbacks in practical use because they must be used outdoors, and they are slow and do not work in the evening or on cloudy days.

Education interventions

Educational intervention can contribute to reducing exposure to smoke by developing a social marketing effort in alerting people to the dangers and encouraging a willingness to alter living and cultural practices which could have a significant impact on mitigating exposure to IAP. These interventions “must be based on felt needs…” with emphasis and sensitivity to gender issues. Evidence of one successful government intervention was revealed by China who, between 1980 and 1995, disseminated 172 million improved cookstoves. This effort proved more successful due to the inclusion of local users, particularly women, who were involved in the design and fieldwork process.

Kenya and modern energy

As of 2004, Kenya has shown a willingness to undertake biomass energy issues with the understanding that “consumption is associated with indoor air pollution and environmental degradation”. Suggestions from the United Nations Development Programme include establishing an institution that will deal exclusively with biomass energy by developing policy guidelines on sustainable firewood, charcoal, and modern biomass such as cleaner fuels and wind, solar, and small scale hydropower. see Renewable Energy in Africa Short-term solutions rest in more efficient domestic energy use by way of improved cook stoves which provide more affordable options in the near future than a complete shift to nonsolid fuels. Long-term solutions rest on transition to modern cleaner fuels and alternative energy sources within a broad international and national policy and economic agenda. Government support for long-term solutions is feasible as witnessed by current efforts in Zambia to develop policy to promote biofuels.

Conclusion

National and international effort must be stepped up to advance short and long term solutions for the millions of women and children who suffer from poverty and disease as a result of indoor air pollution. Scientists predict the African continent will be the first to experience the effects of global warming where widespread poverty will put millions at further risk due to their limited capabilities to adapt. The potential is great for a more sustainable Africa with commitment from within and outside the region.