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Indoor Air Pollution in Rural Tigray
This is a summary of a report of a study initiated jointly by WHO and the Ethiopian Ministry of Health, Environment and Hygiene. The study aimed to test' monitor and document indoor air quality in Tigray kitchens. Tigray is a region in northern Ethiopia now, emerging from the ravages of civil war. It will take time. effort, and resources to repair and reverse the environmental degradation resulting from years of neglect. In the meantime, poor families have to bear the brunt of the problems and, as is often the case, it is women who suffer most. Because of the almost exclusive use of dung for fuel and the small, enclosed area in which they cook, pollutant concentrations in Tigray kitchens are very high. In Tigray, cattle dung is supplemented with sorghum stalks for two months of the year. Women whose families do not own cattle have difficulty in collecting dung, and complained to the researchers about the growing fuel scarcity. Some women said that, as a consequence, they cooked less often and their families were forced to eat cold food. The staple food consists of injera, a type of flat bread made from tef (grass seed grown typically in the highland regions of Ethiopia). This is prepared about three times a week and eaten twice a day with various types of wat, a thick sauce or stew. Coffee is also prepared after each meal. Most households have a stove with a place for an injera baking pan (mtad), connected by a short tunnel to a pot seat for cooking watt At the back of the injera stove there is a small smoke outlet, which may be extended to a nearby window. The women build the stoves themselves and say that they would like chimneys, but the men who build the houses do not know how to construct them. The kitchens are separate from the living quarters. Round in shape, they have an average area of about five square metres, with stone walls and straw, mud or stone roofs. There are usually two smoke outlets in the roof and the door remains open during cooking. [top] [end]Measuring indoor air qualityIn order to analyze the air quality in a typical, rural Tigray household, measurements were taken in 11 kitchens while injera was being cooked. Two methods were used for measuring carbon monoxide (CO) concentrations and one each for total suspended particles (TSP) and for poly-aromatic hydrocarbons (PAH). (Details of the procedure and instruments are given in the full report.) The results are summanzed in table 1[top] [end]Total suspended particulatesMaximum concentrations were in the range 83 to 175mg/m3, but were typically in the region of 20mg/m3 The lowest concentrations were measured in the households with chimneys. All levels are exceptionally high and are caused by
[top] [end]Poly-aromatic hydrocarbonsSome measurements of PAH in the particulate samples, taken near the stove while starting the fire showed peak carbon concentrations up to 417mg C/m3 and very large tar spots. Average values were however 47mg C/m3, which generally confirm the presence of carcinogenic substances.[top] [end]Carbon monoxideMaximum concentrations were in the region of 310 to 600 ppm (parts per million), although average CO concentrations were only 44 ppm as measured with the diffusion sampler and only 5ppm in the households with chimneys. The wind caused immense fluctuations in the CO concentrations and when the wind blew into the chimney the concentrations increased substantially. The CO distribution in the rooms varied for different heights and distances from the stove fuel consumption, power and efficiency .An average of 0.74kg of fuel is required to cook I kg of injera dough which shows a very low stove efficiency. A large (25kW) well-distributed fire underneath the mtad is necessary to generate the high, even temperatures needed to bake good injera. Dung burns very poorly and at times the CO content of the exhaust fumes was greater than 4000 ppm, showing a CO combustion efficiency of only 8?%. This represents a significant loss in energy, and confirms the highly polluting potential of the stoves when used with cowdunc.Table 1: Air quality in typical rural Tigray kitchen
The present poor quality of indoor air in Tigray kitchens is clearly a very pressing development problem. Even though the field tests are far from being representative of the wider situation and the sample is small, there is no doubt about the severe health risk posed to women and young children. [top] [end]Womens' commentsThe women surveyed said that they would like chimneys because smoky kitchens are one of the biggest problems they face in their daily life (more than collecting water). They complained about the problems caused by smoky kitchens: their eyes itch. they have regular headaches and suffer coughing. Some believed that their heart problems were also caused by the smoke. The tests tend to confirm that although existing chimney-stoves do improve the overall indoor air quality. smoke clearance is only partial, and that chimneys leak smoke during ignition and when it is windy. The women who used chimney stoves said they were slow and difficult to light. The tests also indicated that the chimney stoves significantly increase the amount of fuel required.
[top] [end]RecommendationsBecause of the very low purchasing power of most Tigray households, a switch to better-quality fuels would be impossible. It also means that improved stoves are the only short to medium-term option, and even then only if they are very cheap. Although the data available is rather limited, all the indications are that future work should focus on:
Major improvements in kitchen conditions will only be made it home economists and the Tigray women themselves are actively involved. This would be far more effective than distributing readymade stoves through commercial channels. [top] [end]Contents: Boiling Point 34: Smoke Removal
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Page created:
21 August 2007; Last edited:
21 August 2007; Version: 0 | ||||||||||||||||||||||||||
Pagename: IndoorAirPollutionInRuralTigray @HEDON: NUGA | ||||||||||||||||||||||||||
