Alliance Reports and Research, Health, Environment | David Pennise, Simone Brant, Seth Mahu Agbeve, Wilhemina Quaye, Firehiwot Mengesha, Wubshet Tadele, Todd Wofchuck | Released on
June 10, 2012
This study was undertaken to assess the potential of two types of improved cookstoves to reduce indoor air
pollution in African homes. An ethanol stove, the CleanCook, was tested in three locations in Ethiopia: the
city of Addis Ababa and the Bonga and Kebribeyah Refugee Camps, while a wood-burning rocket stove, the
Gyapa, was evaluated in Accra, Ghana. In both countries, kitchen concentrations of PM2.5 and CO, the two
pollutants responsible for the bulk of the ill-health associated with indoor smoke, were monitored in a before
and after study design without controls. Baseline (‘before’) measurements were made in households using a
traditional stove or open fire. ‘After’ measurements were performed in the same households, once the
improved stove had been introduced. PM2.5 was measured using UCB Particle Monitors, which have
photoelectric detectors. CO was measured with Onset HOBO Loggers. In Ghana and Kebribeyah Camp, CO was
also measured with Gastec diffusion tubes. In Ghana, average 24-hour PM2.5 concentrations decreased 52%
from 650 μg/m3 in the 'before' phase to 320 μg/m3 in the 'after' phase (p=0.00), and average 24-hour
kitchen CO concentrations decreased 40% from 12.3 ppm to 7.4 ppm (p=0.01). Including all three subgroups
in Ethiopia, average PM2.5 concentrations decreased 84% from 1 250 μg/m3 to 200 μg/m3 (p=0.00) and
average CO concentrations decreased 76% from 38.9 ppm to 9.2 ppm (p=0.00). 24-hour average CO levels in
households using both the Gyapa and CleanCook stoves met, or nearly met, the World Health Organization
(WHO) 8-hour Air Quality Guideline. PM2.5 concentrations were well above both the WHO 24-hour
Guideline and Interim Targets. Therefore, despite the significant improvements associated with both of these
stoves, further changes in stove or fuel type or household fuel mixing patterns would be required to bring PM
to levels that are not considered harmful to health.