Climate impacts of kerosene lamps used in developing countries
By Jeffrey Stumpf
While policy makers focus on carbon dioxide emissions when considering efforts to reduce climate change, a new study, funded in part by NIEHS, suggests that replacing the type of kerosene wick lamps used widely in developing countries would have a major impact in slowing the earth’s warming trend.
The report, presented by a multinational research coalition and published in the journal Environmental Science and Technology, adds the replacement of inefficient kerosene lamps to a list of practical changes that could help limit temperature increases over the next 50 years, while also dramatically improving indoor air quality.
Light produced by kerosene lamps is extremely important for the twenty percent of the world’s population that lacks access to electricity. In fact, previous reports estimate that 77 billion liters of liquid fuel, mostly kerosene, are used annually to light houses without electricity. However, incomplete combustion of the lamp fuel often yields black carbon that absorbs light, thereby heating the atmosphere.
Emission of significant amounts of black carbon
The study presents new laboratory and field measurements showing that 7−9 percent of kerosene consumed by this type of wick lamp is converted to carbonaceous particulate matter that is nearly pure black carbon. In contrast, less than half of 1 percent of emissions from wood combustion is black carbon. The authors note that 3 percent of global black carbon emissions come from these inefficient kerosene lamps.
One of the authors, Kirk R. Smith, Ph.D., is excited about simple opportunities to radically reduce the global footprint of human activities. “There are no magic bullets that will solve all of our greenhouse gas problems, but replacing kerosene lamps is low-hanging fruit,” said Smith, an NIEHS grantee and director of the Global Health and Environment Program at the University of California (UC), Berkeley, in a Nov. 28, 2012 press release. “We don’t have many examples of that in the climate world.”
“There's a lot of interest right now in reducing black carbon as a quick way to reduce climate warming — a way to reduce warming in the immediate future, although not a full solution to long-term climate change,” explained senior study author Tami Bond, Ph.D., a professor of civil and environmental engineering at the University of Illinois at Urbana Champaign.
The report cited several examples of viable alternatives to kerosene lamps in addition to providing reliable and affordable electricity to households. Options include cheap light-emitting diode lamps or even simply more efficient kerosene-fueled lamps.
“There are many inexpensive, cleaner alternatives to kerosene lamps that are available now, and few if any barriers to switching to them,” Smith remarked.
Burning kerosene as an environmental health hazard
In poor households in developing countries, people live with and inhale the smoke generated from cooking and heating fires. The most recent estimates, which are part of the Global Burden of Disease Study 2010 published Dec. 13, 2012, indicate that approximately four million people die prematurely each year from illness attributable to household air pollution due to biomass and coal cooking fuels alone.
Work funded by NIEHS and others, however, is starting to show that kerosene smoke whether from stoves or lamps is an additional important cause of ill health in these poor households. NIEHS has also funded a large new study by Smith and colleagues just starting in Nepal to examine the tuberculosis risks of kerosene smoke in much more detail.
Replacing kerosene lamps is thus important not only for reducing global climate change but also decreasing the risk of adverse health outcomes.
“Getting rid of kerosene lamps may seem like a small inconsequential step to take, but when considering the collective impact of hundreds of millions of households, it’s a simple move that affects the planet,” said first author and UC Berkeley graduate student Nicholas Lam.
Citations: Lam NL, Chen Y, Weyant C, Venkataraman C, Sadavarte P, Johnson MA, Smith KR, Brem BT, Arineitwe J, Ellis JE, Bond TC. 2012. Household light makes global heat: high black carbon emissions from kerosene wick lamps. Environ Sci Technol 46(24):13531-13538.
Pokhrel AK, Bates MN, Verma SC, Joshi HS, Sreeramareddy CT, Smith KR. 2010. Tuberculosis and indoor biomass and kerosene use in Nepal: a case-control study. Environ Health Perspect 118(4):558-564.
(Jeffrey Stumpf, Ph.D., is a research fellow in the NIEHS Laboratory of Molecular Genetics Mitochondrial DNA Replication Group.)