As poor people’s incomes increase theytend to switch to cleaner fuels for cookingand heating. In time, as poverty levels arereduced, lethal levels of indoor airpollution will fall. But poor people cannotafford to wait for a rising tide ofprosperity to clean up the air in theirhomes, and the international communityhas an obligation to ensure life is mademore tolerable for today’s generation.There are actions that can be taken in theshort term, that will ensure long termbenefit for those at risk.

In a review of ways of reducing smokelevels, undertaken for the WHO and theUnited States Aid (USAID), alternativeswere considered according to three areas.These comprise: interventions at thesource of smoke; interventions directedtowards the living environment; andinterventions aimed at the user.

Cooking on a cleaner fuel

The most effective means of reducingindoor air pollution is to switch to cleanerfuel that produces significantly loweremissions. While this may not currentlybe an option for many people due to highcosts, lack of access to the fuel and otherbarriers, for those who are able the switchfuels, the benefits are great.

In many urban areas cleaner fuels, suchas kerosene and LPG, cost less per unit offuel than biomass. However, there is oftena larger cash investment needed topurchase the fuels and the stoves. Forexample LPG must be bought each weekor month by the bottle, but poor peopleusually purchase fuel daily in smallquantities. Making fuel available insmaller quantities would benefit poorercustomers. Mechanisms such as micro-

Reducing exposure to indoor air pollutionThe solution to indoor air pollution is relatively simple: either stopsmoke getting into the home or remove it from the home. Thehealthiest option is to cook with a cleaner fuel. However, for theforeseeable future, many poor people will have little option but to cookon low-grade fuels. The best option for them is to safely remove thesmoke from the kitchen. Experience shows that there is no ‘one size fitsall’ technical fix. A lasting solution depends upon the activeparticipation of those at risk, poor women.

Source of smoke

IImmpprroovveedd ccooookkiinngg ddeevviicceessChimneyless improved biomass stovesImproved stoves with chimneys

AAlltteerrnnaattiivvee ffuueell––ccooookkeerr ccoommbbiinnaattiioonnssBriquettes and pelletsCharcoalKeroseneLPGBiogasProducer gasSolar cookers (thermal)Other low smoke fuelsElectricity

RReedduucceedd nneeeedd ffoorr ffiirreeEfficient housingSolar water heating

Living environment

IImmpprroovveedd vveennttiillaattiioonnHoods/fireplacesWindows/ventilation holes

KKiittcchheenn ddeessiiggnn aanndd ppllaacceemmeenntt ooffssttoovveeShelters/cooking hutsStove at waist height

User

RReedduucceedd eexxppoossuurree tthhrroouugghh ooppeerraattiioonnooff ssoouurrcceeFuel dryingUse of pot lidsGood maintenanceSound operation

RReedduuccttiioonnss bbyy aavvooiiddiinngg ssmmookkeeKeeping children out of smoke

Table 2: Potential interventions for the reduction of exposure to indoor air pollution.53

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credit loans or subsidies may also help toreduce the cost of fuel switching.42

In rural areas there is less incentive toswitch fuels, as biomass is gathered at nofinancial cost to the user. Cost issuesaside, there are other concerns about fuelswitching. Many of the poorest membersof society in developing countries maketheir living from collecting and sellingbiomass fuel. The result of a wholesaleshift from biomass fuel could be theremoval of a vital source of income forsome of the most vulnerable people insociety.43

The United Nations DevelopmentProgramme’s LPG Challenge aims atovercoming the barriers for ruralcommunities to access LPG in countrieswhere it is readily available in urbanareas.

Cleaner fuel and climate changeThere may be concerns about the climatechange impact of switching to a non-renewable, petroleum-based fuel.Professor Kirk Smith, from the Universityof California, tackled this argument in a

paper entitled ‘In Praise of Petroleum’,45

published in Science in December 2002.He argues that if the two billion or sopeople currently reliant on biomass wereto shift to LPG, emissions of greenhousegases would increase by less than 2%.Professor Smith goes on to illustrate howthe smallest of increases in efficiency inthe world car fleet could counter this rise.If an improvement of just 0.5% per year(5.1% over 10 years, not much more thanone mile per gallon) were made, thiswould free up annually sufficient fuelenergy for the cooking needs of all thetwo billion currently burning biomass.

Over-consumption of fossil fuels isprimarily a problem for the industrializedworld. As Professor Smith puts it:

‘Rather than excluding petroleum, some ofthis one-time gift from nature oughtactually to be reserved to help fulfill ourobligation to bring the health and welfareof all people to a reasonable level: anessential goal of sustainable development,no matter how defined.’45

14

Figure 8: Emissions alongthe energy ladder.29 TThhee eenneerrggyy llaaddddeerr

The energy ladder is a scale which rates the quality of household fuels. At the lower end ofthe ladder are the traditional biomass fuels: dried animal dung; scavenged twigs and grass;through to crop residues, wood and charcoal. Moving up the ladder, coal is next, followed bykerosene, bottled and piped gas, biogas (from digesting animal dung) and electricity. Gaseousfuels are the cleanest burning household fuel. In general, as households climb the ladderthere is an associated increase in the sophistication of the cooking technology, its cleanliness,efficiency and its cost.29 Cooking with electricity is too costly for poor households.

CO (g

/mea

l)

1.8

Dung

PM (g/m

eal)

CO

PM

40

35

30

25

20

15

10

5

0

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

10

10

Cropresidues

Wood Kerosene Gas Electricity

‘Kerosene and LPGactually produce fewergreenhouse emissionsper unit of energyservice than biomassfuels used in traditionalways.’

UNDP World EnergyAssessment21

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Using solid biomass fuel can, in fact,produce higher greenhouse gas emissionsper meal than fossil fuels, kerosene andLPG,26 even where the biomass fuel isharvested sustainably. This is due toinefficient combustion of the biomass fuel,which releases products of incompletecombustion, including methane, whichhave a greater greenhouse potential thancarbon dioxide. In some situations,therefore, fuel switching to fossil fuelsmay be recommended to reducegreenhouse gas emissions.

Biogas from dung and other waste

Biogas is extremely effective, as it convertsa renewable material (dung and otherorganic waste materials) into a gaseous,clean fuel. While biogas is being introducedin parts of Asia very successfully – thereare over 120 000 bio-gasifiers in Nepalalone – the culture in much of Africamakes it harder to introduce there. Furtherresearch and development of renewable,clean cooking fuels will be essential forlonger term cooking options.

15

GGhhaannaa LLPPGG44

Promotion of LPG started in Ghana in 1990 to reduce the wastage caused by flaring constituent gases at the refinery, andto reduce dependence on charcoal and fuel wood. The Ministry of Energy took the lead in promotion and price control ofLPG use for cooking. The programme involved: public awareness raising to increase demand for LPG; door-to-door delivery;reduced cost cylinders; encouragement of LPG use in schools and hospitals; promotion of LPG with commercial foodvendors.

Elements of the traditional cook stove were used in the design of the locally promoted LPG stove. Between 1989 and 1997cylinder sales increased from 80 000 to 600 000 per year, with 22.7% of households in the capital city, Accra, using LPG.Promotion of LPG to lower income households and in rural areas has not been so successful, however.

The UNDP LPG Challenge is now planning to work with local stakeholders in Ghana to overcome the barriers for LPGpromotion in rural areas, and to encourage private companies to sell to rural customers.69

A household biogas plant inNepal.

Reducing exposure

ITDG/S

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Getting smoke out of the house

The biomass trapWhile switching to a cleaner fuel is themost effective means of reducing indoorair pollution, abject poverty will meanmany hundreds of millions of peopleworldwide will have no access to fossilfuels for a very long time to come. Theywill be trapped into using biomass as theirprimary fuel. The barriers to accessingclean fuels are many, for example:

• For extremely low-income householdsthe up-front costs of purchasing newcooking technologies, as well as theon-going cost of fuel, are beyond theirmeans.

• Where biomass is collected free ofcharge, even though it takes aconsiderable amount of time to collect,using limited cash income to purchasecooking fuel is not given priority inmany very low-income households.

• In extremely remote areas it is verydifficult to provide a reliable supply offuel, and transport costs will increasethe price of fuel supply.

• Many developing countries do not yethave sufficient infrastructure todistribute LPG or kerosene on a widescale.

Where biomass fuels will remain thedominant domestic fuel, it is essential tomaintain a reliable and sustainable supplyof fuel wood. Fuel wood collection for usein rural areas is not a significant cause ofdeforestation as women generally collectdead wood and twigs and rarely chopdown trees.26 However, in environmentallystressed areas, fuel wood collection has asignificant impact. Where deforestationhas occurred, often due to eithercommercial logging or land clearance foragriculture, there is a need to providesustainable fuel wood sources for ruralpopulations.

In many countries trees are often felledunsustainably to provide fuel wood andcharcoal to supply urban demand. Urgentpolicies and measures are required here tocurtail the loss of forestry. Many people

make a living, legally and illegally, in thesupply of fuel to cities in the developingworld. It will be essential to maintainthese livelihoods, while restoring forestresources.

For those trapped into using biomassas their main domestic fuel, options forreducing exposure to indoor air pollutionwill entail safe ways of getting smoke outof the home.

Smoke hoods, eaves and windowsFor the foreseeable future billions ofpeople will continue to use biomass astheir main fuel. Therefore it is essentialthat efforts to reduce exposure to indoorair pollution be directed at the realitypeople face now. Smoke will continue tobe produced, so it needs to be removedfrom the house.

Substantial reductions to smokeexposure have been obtained withrelatively simple methods. For example,an ITDG project in Kenya reducedparticulate and carbon monoxidepollution in homes by nearly 80%through the use of smoke hoods andimproved ventilation in the home.

Smoke hoods work on the sameprinciple as flues and chimneys, but havethe advantage of being freestanding andindependent of the stove.47 Smoke hoodshave been shown to achieve substantialreductions (80% in some homes) inrespirable particulates and carbonmonoxide.

By enlarging the eaves spaces in atraditional house, substantial benefitscan be achieved. For example, in theKenya project respirable particulateswere reduced by 60%. The number ofhouses showing very high levels ofsmoke pollution was also reducedsignificantly.46

However, the enlargement of windowsin the same project seemed to have littleimpact on indoor air pollution, althoughwindows are required in houses withsmoke hoods to allow an air flow throughthe house.46 The enlarged windows didhave benefits, such as improving lightingin the houses, but did not addsignificantly to the reduction of smoke.

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Kenyan study46

The ITDG Smoke Project was launched in1998. Working with 50 households in ruralKenyan communities, the project aimed toreduce exposure to indoor air pollution.The participatory approach adopted forthis work meant that the project workersarrived willing to listen to the needs of thehouseholds rather than to impose specificinterventions.

The interventions chosen were: smokehoods; increased ventilation throughwindows and eaves; and more efficientcombustion through improved stoves.

• Smoke extraction through smokehoods was selected in favour ofchimney stoves, based in part on thesuccessful operation of smoke hoods ina previous project and on the failure ofthe chimney stoves installed during agovernment scheme.

• Increasing the amount of ventilationinvolved installing a window or cuttingeaves spaces into the wall at roofheight.

• The Upesi stove has been shown toreduce fuel use by about 40%compared with traditional three-stonefires. Households that have used themstate that the kitchens are cleaner,children are safer from accidents andthere is a considerable saving in theuse of fuel wood.

An important component of this programme was the exchange visits that allowed localdissemination of ideas. Initial reluctance on the part of many cooks turned to enthusiasmonce they had seen the interventions in place in other people’s kitchens.

The results showed substantial reductions in particulate matter and carbon monoxide levelsin the households after the installation of interventions. The most effective intervention wasthe use of smoke hoods, which reduced particulate pollution by an average of 75% andcarbon monoxide in the room by 78%. The personal exposure experienced by the women inthe study was reduced to about one third.

Additionally there were some very positive impacts on poverty. Community membersobserved that they felt healthier; there was more time to engage in economic activities whenthe stoves were used; and local artisans increased their income from the manufacture ofinterventions. There were significant improvements for women, above and beyond theirhealth. Participating women were found to have increased confidence and improved statusin the community.

These changes are not without their problems, with some reports that houses were nowcooler, concerns about privacy and security which were overcome by using wire mesh overopenings, and some financial problems for households who were contributing to the costsof the programme.

This was the first stage of a programme of work with the target communities. The on-goingwork is now aimed at achieving wider use of the interventions through public awareness,developing local markets for the interventions and establishing local financing mechanismsto help households afford the necessary changes in their homes.

A West Kenya kitchen with smoke hood, largeeaves space and windows.

Reducing exposure

ITDG/D

r Nig

el B

ruve

Responses tointerventions in theKenya study

‘I can now do mystudies in the kitchen,’one boy, Sironga Masur,told the team. ‘I neverused to study with thefire on due to choking

smoke.’

‘Now I can have abreath of fresh air. Nomore tearing, no morered eyes, bye-bye to

headaches.’

‘You no longersuffocate while in the

kitchen cooking.’

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Cutting smoke volumes

Improved biomass stovesImproved stoves were primarily designedto increase energy efficiency. The Upesistove, for example, has been promotedthroughout Kenya and can reduce fuel useby about 40%.46 These stoves weredeveloped with good reason. Reducingfuel requirements will ease demand onforestry, lessen the burden on womencollecting fuel, and in urban areas cutexpenditure on fuel.

Some improved stoves can also helpreduce emissions of smoke. Studies haveshown a small decrease from certainimproved stoves, although many stoves infact increase emissions if air flow to thefuel is restricted.53

If an improved stove incorporates aflue or chimney, one would anticipatesmoke would be reduced. There are somevery effective chimney stoves, which havebeen designed to remove smoke from thehouse, and tested in the home to show asignificant reduction in smoke. Goodexamples are the rocket stove48 andEcostove,49 which are increasingly beingused in Central America.

However, there are also potential

problems with many chimney stoves. Fluesmay not perform well if they are notinstalled properly, they can be poorlydesigned and can be fragile. Chimneys areexpensive and may be ineffective if thesmoke returns through doors andwindows.47 They can also block up quicklywith soot and require regular cleaning.

These points indicate that improvedstove must be more rigorously designedand monitored to demonstrate asignificant impact on IAP in the home.

Reducing the need for fire

Hay boxesA very simple technology can reduce theneed for fuel for cooking – this is thefireless cooker, or a ‘hay box’. This actslike a slow cooker, and is good formaking soups, rice or stews. The food isheated to boiling, then placed in a boxfilled with insulating material, such as hayor crumpled newspaper.50 The foodcontinues to cook slowly. Thedevelopment organization Winrock foundthat the hay box was very popular withthe women’s groups they worked with inNairobi, where hay boxes are proving aspopular as improved stoves.51

TThhee ssuucccceessss ooff tthhee EEccoossttoovvee iinn NNiiccaarraagguuaa49

After diarrhoea, acute respiratory illness isthe greatest cause of death in young childrenin Nicaragua. In both rural and urban parts ofthe country, three-stone fires are stillcommonly used. In urban Managua andsmaller towns, a new stove is making inroadsto replace the traditional stove. This is theenergy efficient Ecostove, developed by theNGO Proleña, with technical support fromAprovecho.48 The Ecostove is an innovativewoodstove which is insulated, with hotemissions (smoke) vented through a chimney.The stove is sealed, preventing nearly allindoor air pollution, and reduces consum-ption and expenditure on wood fuel by 50%.It is common for women to increase theirincome by creating a small business to cooktortillas and soup to sell at their back door orfrom small stalls. This requires long periodsby the stove. The Ecostove has beenparticularly beneficial to these households.

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Woman cooking on an Ecostove in Nicaragua.

Roge

rio

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eiro

de

Miran

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Solar water heaters and cookersSolar water heaters, which absorb theheat of the sun, can fairly consistentlyprovide water at 60oC. This has beenestimated to result in a 30% reduction inthe amount of fire use and therefore,potentially, a 30% reduction in exposureto air pollution. They need not be costlyas effective systems can be constructedfrom black piping and plastic drums.53

As much of the need for improvedcooking comes from countries withabundant sunshine, it would seem alogical step to move towards solar power,and there are some very strong advocatesfor this technology. However, there arealso some serious concerns.

Solar cookers, which concentratesunlight directly to cook food, have beenseen as a clean alternative way ofcooking. Unfortunately there has beenlimited success in practice. The use ofsolar energy means preparing a meal atmidday, which does not coincide with themain family mealtime in many cultures. Italso requires the cook to work out ofdoors, which reduces privacy whilecooking and makes cleanliness difficult.16

For solar cookers to be used more widely,they must be developed along with theusers to ensure greater acceptance fromthe target community.

Photovoltaic solar home systems,which produce electrical power, are notcapable of delivering the levels of powersufficient to cook a family meal. They arealso, currently, very expensive for mostpoor people.

Changing patterns of behaviour

Simple changes in the way the cook behavescan reduce exposure to smoke. Forexample, making sure that fuel wood is drycuts emissions. The use of a pot lid canreduce the fuel consumed during simmeringby a factor of three and overall emissionlevels by almost a half. Keeping childrenaway from the fire is also an obvious wayof reducing their exposure – but if they arehabitually carried on their mother’s back,or the mother is the only childminder fortoddlers, this can be very difficult.53

Cooking outdoors would, in manyinstances, reduce exposure to indoor airpollution, and in some parts of the world,for example the aborigines in Australia,this is the norm. However, for mostcultures cooking indoors is normalpractice.

There are some practical objections tocooking outdoors. There is a need to keepcool (when the sun is hot outside); there isthe need to keep warm (when the fire isrequired for heating); there is a need tokeep the fire sheltered from the wind asthe heat is directed away from the pot;there is a need to keep the food cleanfrom wind-blown dirt; and there is theneed to keep safe (a closed kitchen keepsfood safe from thieving people anddogs).52

There may also be cultural objectionsin some societies – people do not like tohave others see what they are eating – andthe fire is sacred, a source of life, andtherefore needs to be at the heart of thehousehold.

Heating the home

Most of the interest in the impact ofindoor air pollution has concentrated onthe use of stoves primarily as devices forcooking in the tropics. However, in eventhe hottest countries, there may be aneed to heat the home, especially atnight. And in a number of regions, forexample the Himalayas and the Andes,space heating is essential. In northernPakistan, for example, summertemperatures can reach 45oC yet fall to–40oC in the winter. Exposure to smokeis exacerbated enormously whenmembers of the family spend longer bythe fire during the winter. The increasedneed for fuel creates another burden forwomen. Unfortunately, stoves that arewell insulated, though more efficient atcooking, will release a smaller amountof energy into the room. And theaddition of chimneys will conduct heataway from the space where it is needed.These needs have not been well cateredfor in the development of stovetechnology.16

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Some reasons whywomen do not cookoutside

• Climate – need tokeep cool (when it isblazing hot outside),need to keep warm(when heating isrequired) and theneed to keep dry(during the rainyseason). There isoften switchingbetween inside andout depending on theweather conditions.

• Gender – the kitchenis a woman’s domain,where she keeps herutensils and foodordered and clean,implying the need fora private space.

• Cultural – people donot like other peopleseeing what they areeating. People regardthe fire as sacred –and so it has to be atthe heart of thehousehold.

• Energy – cookingoutdoors burns muchmore fuel due to thewind. The wind alsoblows dirt and duston to the food.

• Safety – the need tokeep safe and to stopfood being stolen byother people oranimals.

Reducing exposure

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Where there is a need to heat thehome, thermally-efficient housing canreduce, or even eliminate the need forheating, reducing the family’s exposure topollution. There are some measures, suchas correct solar orientation, that costnothing at the time of construction.Where insulation is installed, smoke mustbe vented from the house.53

Identifying appropriate solutions

Cooking is a deeply cultural and privateaffair, as it occurs in the home. Experiencehas indicated that there is no point tryingto dictate a solution to a community. Thisis a view supported by a WHO andUSAID-supported consultation on indoorair pollution and health: ‘A single issue,technology-driven approach to indoor airquality is doomed to failure … Such anapproach would limit the choices

available to the local community andfrequently demands of them changes thataffect numerous aspects of their lives.’The authors argue that ‘the key to successis to adopt project approaches thatbroaden the range of secure andsustainable choices available to the localactors and thus to enable them to devisetheir own solutions’.53

Any programme must be based onwhat is acceptable to the community.There is no point investing massiveresources into something that will not beused. For example in Sri Lanka, earlystove projects were aimed at what the‘experts’ assumed was the key issue. Butthe emphasis on fuel-efficiency at the costof users’ priorities often resulted in lowacceptance amongst households.54 This is acommon factor in the failure of manyunsuccessful stoves programmes aroundthe world.

20

Selecting appropriate technologies – comparing experience in Sudan, Kenya and NepalITDG is working in three very different locations to develop locally appropriate solutions to indoor air pollution.55

Participatory approaches have enabled the community to select solutions that suit their own needs. Their choice oftechnology, in each location, was influenced by cultural aspects, cost of both the technology and the fuel, geographicallocation, access to fuels and climate.

In the refugee settlement in Kassala, Sudan, the community identified LPG as an appropriate solution once microfinancewas made available to cover the initial cost of the stove. The scheme is popular, and already others outside the projectare using the credit system to buy stoves. Fuel costs are much lower for LPG than for charcoal and wood in Kassala, sorepayments can be offset by reduced fuel costs.

In the communities around Kisumu town in Kenya, wood fuel is much cheaper than LPG or collected ‘for free’, so mosthouseholds have elected to continue using biomass. Smoke hoods and eaves spaces are proving effective. A fewhouseholds could afford to choose LPG.

In the remote, cold mountain village of Gatlang in Nepal, solutions have been more difficult to identify as energy is neededto heat the house as well as to cook the food. It is remote, making LPG or kerosene unavailable, so biomass is the onlysolution. Home insulation has been identified as a possible means of retaining room heat whilst reducing the need to burnfuel wood for space heating. Ways of venting the smoke are currently being developed, along with metal stoves to reducefuel use.

Table 3: Solutions chosen by three different communities.

CCoouunnttrryy LLooccaattiioonn SSoolluuttiioonnss cchhoosseenn bbyy ccoommmmuunniittiieess56

Kenya Kisumu, town Upesi improved stove, smoke hoods, eaves space, hay boxes, LPG

Sudan Kassala, refugee settlement Mostly LPG

Nepal Gatlang, remote mountain village (cold area) Venting smoke, improving home insulation

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