Indoor Air Pollution: Pragmatic Smoke Mitigating Interventions for Reducing Co and Pm2.5 In Traditional Tukul Houses The Case of Butajira area
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Date
2023-10-01
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Addis Ababa University
Abstract
A considerable number of people are residing in substandard spaces that fall below the WHO recommended
air quality limits which includes exposure to indoor air pollution. The wide use of solid biomass coupled
with indoor cooking are major contributing factors for high concentration of indoor air pollutants in
Ethiopia. Over 95% of the Ethiopian population relies on solid biomass for household energy consumption
and majority of them reside in rural vernacular houses where multiple functional spaces are overlapped in
a single space. The lack of ventilation in these spaces and the amount of time spent indoors from cooking
to sleeping etc. makes the occupants vulnerable to multiple health problems. The common health problems
in the study area are recognized as side effects of prolonged exposure to indoor air pollutants. This research
investigates the relationship between indoor air pollution in rural tukul houses and architectural
modifications that can decrease selected indoor air pollutant concentrations in Butajira, Southern part of
Ethiopia. The aim was to measure the 24hr PM2.5 and CO concentrations, study the architectural features
of the tukuls and experiment with ventilation by providing multiple openings and altering the interior layout
to study the indoor air pollution level reduction. A controlled experimental study was conducted in three
selected households. The experiment had four phases where the first one measured the initial pollutant
concentration levels, the second one introduced a window in the south-west orientation, the third one
provided a second opening to control the air path and the final phase altered the location of the cook stove
to achieve maximum efficiency. The results of the experiment confirmed the current pollutant
concentrations profoundly exceed ideal WHO limits. The lowest before intervention CO concentrations
were over two times higher than homes without indoor cooking and WHO recommended limits. Similarly,
the lowest initial PM2.5 limits were 13 times higher than the maximum WHO limits. In two of the study
houses the intervention successfully decreased both CO and PM2.5 concentrations. The best results were
recorded in the fourth phase where PM2.5 dropped by 49.6% and CO showed an 87.6% decrease. The
combined intervention where both openings and interior layout were altered showed the most positive
results. In one study house the impact of context, activity pattern and existing architectural elements
resulted in increased measurements. It was concluded that the contextual influence at an urban scale,
interior layout/partition, cooking pattern and complete detachment of cooking spaces have the best
potential for improving indoor air quality in existing tukul houses.
Keywords: INDOOR AIR POLLUTION, VENTILATION, OPENING DESIGN,
CONTROLLED EXPERIMENT, TUKUL HOUSES