Occupational exposure to indoor air pollution among bakery workers in Ethiopia; a comparison of electric and biomass cookstoves

Introduction: The indoor air pollution (IAP) produced by the domestic combustion of solid fuels is responsible for up to 4 million deaths annually, especially among low and middle income countries. Occupational exposure within the food preparation industries of these nations remains underexplored. Here we present our findings of the IAP produced during the commercial production of injera, a traditional Ethiopian foodstuff, from bakeries in Addis Ababa, Ethiopia. Methods: Measurements of PM 2.5 , black carbon, and CO were collected from 30 bakeries and their employees. Measurements were compared between bakeries using biomass and electric cookstoves. Respiratory health data of 35 bakery employees were collected by an interview-based questionnaire. Results: Measurements of PM 2.5 , black carbon, and CO were significantly higher among biomass bakeries than electric. For example, personal exposure to PM 2.5 from biomass cookstoves was double that of electric cookstoves (geometric mean: 429.6 µg/m 3 vs. 215.6 µg/m 3 , p Conclusions: The use of biomass powered cookstoves in the commercial production of injera contributes to IAP production and the reporting of respiratory symptoms. As injera is the staple foodstuff of Ethiopia, a widespread conversion to electric cookstoves is likely to have a significant impact upon occupational health.