Health Benefits of Replacing Kerosene Candles
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Health Benefits of Replacing Kerosene Candles with Solar Lamps: Evidence from Uganda Chishio Furukaway First Draft: July 2012 This Draft: August 2017 Abstract A randomized controlled trial in rural Uganda shows that there can be improvement in air-quality-related health such as headaches, chest pain, fever, and eye irritation if non-electrified households switch from kerosene to solar lamps. This five-month study worked with a sample of 155 schoolchildren. Those who received solar lamps reported having better overall air-quality-related health (0.25 standard deviation of baseline distribution, 6% lower probability of any symptoms), although there was no statistically significant change in self-reported cough symptoms or in lung capacity, as measured by spirometer tests. The health improvements were concentrated in school exam periods, most likely because students who switched to studying under solar lamps were exposed to less indoor air pollution. While health benefits exist, a follow-up survey shows that poor maintenance and low adoption remain major challenges for scaling up this new technology. JEL Code: Q42, Q53, Q55 The key words for the paper include indoor air pollution, respiratory health, solar lighting, and technology adoption. yContact: [email protected], 617-767-1209 Department of Economics, Massachusetts Institute of Technology, E52, 50 Memorial Drive, Cam- bridge, MA 02142 *I thank Andrew Foster for his valuable advice in economic analysis, Sriniketh Nagavarapu and David Weil for their initial encouragement, Esther Duflo, Kaivan Munshi, Abu Shonchoy, Daniel Prinz, Benjamin Marx, Alonso Bucarey, Roman Zarate, and anonymous referees for their feedback, and Bruce Kirenga at Mulago Hospital for medical advice. I am indebted to Ruth Nanteza, Abdulrazaq Nassir, John Ssebayigga, Miho Shinke, and Abdulwahid Ngobya, for their assistance in the fieldwork in Kyannamukaaka, and to the office of Barefoot Power Uganda Ltd., Dirk Kam, Benard Kalyango, Frank Yiga, Joyce Demucci, Annet Nalumansi, and Francis Ejuku, who provided guidance and supplied the solar lamps. Without their support and co-operation from students, parents, and teachers of the Kyannamukaaka community, this research could not have been completed. All errors are mine. 1 1 Introduction Energy poverty, defined as a lack of access to clean and reliable sources of energy, affects billions of people who rely on fuels known to be inefficient and detrimental to air-quality- related health (AQRH). A report from the World Economic Forum states that, \One in five people lacks access to electricity. Energy poverty is not just about the lack of energy, it cuts across { and undermines { all aspects of development" [1]. As of 2013, there are 1.3 billion people who live without access to electricity in developing countries in Africa and Asia and, despite progress in adding communities to the grid, the total number living in energy poverty is not expected to decline by 2030 due to population growth [2]. Lighting sources are an area of household energy that have received relatively little atten- tion, despite their importance for living condition in developing countries. More than 80% of non-electrified households use kerosene-based lighting, usually simple candles in open metal containers that provide light by burning an uncovered wick dipped in kerosene. Although they are the cheapest lighting option in the short run, they provide only dim light (Appendix Figure 1) and emit a level of indoor air pollution (IAP) that is significantly higher than the tolerable limit prescribed by the World Health Organization (Appendix Figure 3) [3]. Recent technological advancement in LED light bulbs and solar photovoltaic panels have made small, rechargeable lamps affordable even for rural households in developing countries.1 Unlike kerosene candles, solar lamps provide bright and clean light with almost zero marginal costs (Appendix Figure 2). If adopted successfully, they have the potential to improve productivity and health, and thereby contribute to alleviating the pervasive and persistent 1The cheapest, reliable solar lamp available in the market costs 10 USD. This is equivalent to six months of kerosene expenditures for households that use kerosene candles. 2 energy poverty in areas electrical grids have not yet reached. This paper examines the new technology's potential to improve air-quality-related health, which has been shown to be damaged by inhalation of kerosene smoke. In a five-month field experiment in rural Uganda, I randomly distributed affordable and portable lamps to approximately half of the 155 upper primary school children. I find that students who received the lamps show improvements in self-reported overall air-quality-related health: 0.25 standard deviation of baseline distribution. This effect was especially concentrated during the students' exam periods. This is likely because the children who did not receive solar lamps were more exposed to IAP as they had longer and more intensive exposure through increased study by kerosene candlelight at night. At the same time, the treatment effect on spirometer measurements, which gauge lung capacity, is very close to zero. In addition, improvement in self-reported cough is modest and not statistically significant except in the first week after the intervention. Additional variations demonstrate that this result is not driven by selective attrition, reporting bias, or income channel. First, the attrition rate is only 1% different between the two groups and thus, the trimming-based bound on treatment effect is tight. Second, the health benefits are concentrated in school's exam periods, suggesting that reporting bias is unlikely to be important. Third, the health outcomes of diarrhea and malaria show no improvement, suggesting that both the income effect through saved kerosene expenditure and reporting bias are unlikely to be contributing factors. Despite potential benefits in terms of health and quality of life the solar lamps deliver, I find that their long-term adoption remains challenging. In this experiment, the research team conducted regular maintenance checks on the lamps. However, six months after they 3 left the study group, over 65% had returned to kerosene candles. The solar lamps were apt to malfunction due to the users' inappropriate usage and maintenance. Furthermore, another paper reporting on academic outcomes [4] shows that the solar lamps may have hindered children's study due to shortages in solar power, causing dim or flickering light. All in all, while solar lamps seem to have positive impact on some health outcomes, the technology in its present and most affordable form is not ready for wide and sustainable scale-up. These findings of improvement in symptoms such as eye irritation, positive effect on study hours, negative effect on test scores, high willingness-to-pay for more lamps, and poor maintenance are consistent with a recent study in rural Bangladesh [5]. The paper proceeds as follows: Section 2 discusses the background and reviews previous literature; Section 3 explains the details of randomized evaluation; Section 4 presents the results; Section 5 discusses the challenges of technology adoption; and Section 6 concludes. 2 Kerosene Candles and Solar Lamps in Uganda 2.1 Lighting Sources in Rural Households Kerosene is the most commonly used lighting fuel in non-electrified areas of Uganda. Gen- erally, lanterns are used by households that are economically better off whereas candles are used by poorer households. Although the percentage of households using kerosene has de- creased over the past decade, it still remains above 60% (Appendix Figure 6). As the map of lighting source distribution (Appendix Figure 7) shows, access to electricity is clustered around the capital, Kampala, and extends only to the major cities. 4 In contrast, solar lamps are a new lighting device that has recently been expanding in Uganda. The World Bank and International Finance Cooperation (IFC) initiated the Lighting Africa Program, which promotes modern lighting technology for rural electrification in Africa. It reports that the market expansion has been dramatic with sales growth of over 90% per year and sold more than 4 million units by 2013 [6]. Solar lamps are part of a larger attempt to bring modern electrical infrastructure to developing areas. For instance, solar panels with cell phone charging capacity have also been a popular device for the villagers. Given the surging concern about energy issues and innovation in renewable energy, the United Nations organized an International Year of Sustainable Energy for All in 2012, which also aimed to promote the application of solar energy in developing countries [7]. It also organized the International Year of Light in 2015, with the goal of promoting sustainability and development in lighting technologies such as solar lanterns. The expansion of solar lamps in Uganda has been relatively successful, thanks to its geography as well as policy support. Due to its location at the equator, Uganda experiences perpendicular sunrays as well as short rainy periods. Uganda's tariff policy, which does not tax imported solar panels, also attracts solar businesses [8]. Although the Solar Lamp Field Test implemented by the German Society for International Cooperation reports that there are some challenges stemming from rainy seasons and the dissemination of knowledge regarding how to fully recharge, use of solar lamps has been expanding steadily throughout the past decade (Appendix Figure 6) [9]. The spread of solar lamps has been documented in multiple literatures on social enterprise [10, 11]. 5 2.2 Indoor Air Pollution and Air-Quality-Related Health The indoor air pollution (IAP) emitted from kerosene candles poses a significant threat to AQRH. Apple et al. report that simple wick kerosene candles emit PM2.52 in concentration per time, an order of magnitude higher than the WHO health guideline [3]. Fan et al. review literature and report that both kerosene candles and lanterns are significant sources of IAP [12]. This level is considerably high for long-term indoor usage, especially for the children whose lungs are in a developmental phase [13].