Abstract:
The use of biomass fuels poses great threats to public health accounting for 32% of the total
attributable burden of diseases due to Indoor Air Pollution (IAP) in Africa. Heavy reliance on biomass fuels for
household energy in Kenya makes the country more vulnerable with 90% of the rural population relying on
biomass fuels for domestic purposes. The objective of this study was to assess effectiveness of improved biomass
cookstoves in reducing kitchen PM 2.5 concentration in Western Kenya region. The data was collected through
continuous real-time monitoring of kitchen pollution concentration for a period of 24 hours using UCB-PATS,
CO monitors, questionnaires and time activity budgets. Data analysis was undertaken by performing ANOVA to
test for their variations from WHO stipulated safe standards. The study found that at 95% CI, mean 24-hr
kitchen CO and PM concentrations from all the stoves were significantly higher than the stipulated WHO
threshold. Three-stone fire had the highest average 24-hour kitchen PM and CO emissions using firewood at
4272.414μg/m 3 (p = 0.000) and 75.4417ppm (p = 0.000), respectively, while Chepkube stove had the least at
682.646μg/m 3 (p = 0.000) and 8.7224ppm (p = 0.000), respectively. It was concluded that, improved biomass
stoves provided an overall reduction in pollutant concentration compared to three-stone fire but the local
innovation Chepkube stove that has been classified as ungraded stove had the highest pollutant reduction. In
addition, indoor air pollution in rural areas is a real health risk. Consequently, it was recommended that
programs aiming to reduce the adverse health impacts of CO and PM 2.5 should focus on measures that result in
larger reductions of PM 2.5 emissions especially during burning and peak periods.
