Clean lighting leads to decreased indoor air pollution and improved respiratory health in rural Uganda

Exposure to smoke is a major cause of respiratory illness in the developing world. To date, cookstoves have been the most widely studied source of smoke exposure in developing countries. We hypothesized that exposure to kerosene lighting, utilized by 86% of rural off-the-grid communities in sub-Saharan Africa may also be a significant source of smoke exposure and may be responsible for respiratory pathology. We performed an interventional field trial including 230 people in rural Uganda to assess the impact of clean lighting on indoor air pollution and respiratory health. Each member of the study households were asked about their exposure to smoke, the types of lighting they used, and their recent history of respiratory symptoms. Next, we provided solar-powered lamps to households in the intervention group, and compared to households in the control group who continued to use kerosene lamps. We monitored indoor air quality in a subset of intervention and control households over a three-month period, and performed an exit survey to assess symptoms of respiratory illness in both groups. All of the households we surveyed were found to use kerosene lamps as their primary lighting source. We found that the average person was exposed to 3.3 hours of smoke from kerosene lamps, as compared to 44 minutes of exposure from cookstoves. Next, we found that average soot levels (elemental carbon) in intervention homes were 19-fold lower than soot levels in control homes. After three months, we observed reduced rates of all symptoms assessed, and significantly reduced risk of cough, sore throat, and overall illness in the intervention homes. Our findings demonstrate that kerosene lighting is a significant source of smoke exposure in the developing world, and that the introduction of clean lighting in homes reliant on kerosene lighting can have a rapid and significant impact on overall health.