When I stumbled upon a paperrecently about stoves in the developing world in Environmental Science &Technology, I vaguely remembered having heard of fundraisers to supply developing regions with new types of stoves. I thought that these appliances would perhaps help people cook their dinners faster — what’s the big deal?
It turns out that these new types of stoves (called “improved cookstoves”) aren’t for getting dinner cooked in less time, but for improving people’s health and the health of the environment.
Hundreds of millions of people in developing countries in South Asia, Africa and South America in many developing areas rely on cookstoves that are fashioned out of mud and stones. They use these stoves for heating and light, not just for cooking, so these stoves are going for many hours at a time.
Traditional mud stoves or open-cook fires generate lots of soot, and these particles can be inhaled deeply into the lungs and have been linked to health problems similar to those associated with cigarette smoking. Women and small children traditionally gather near these fires the most, and many wind up with the same clinical symptoms as cigarette smokers. “Day in and day out, and for hours at a time, women and their small children breathe in amounts of smoke equivalent to consuming two packs of cigarettes per day,” according to a 2006 World Health Organization report. In addition, black soot is a major factor in global warming.
Aid agencies and governments have been seeking replacements for traditional cookstoves and fires to remedy those problems. That’s where “improved cookstoves” or ICs come in. Until now, however, there have been little real-world data on the actual performance of ICs — which have features like enhanced air flow and a battery-powered fan to burn wood and other fuel more cleanly.
In the ES&T paper, Abhishek Kar, Hafeez Rehman, Jennifer Burney and colleagues report that they have conducted the first real-world, head-to-head comparison of ICs and traditional mud stoves. Surprisingly, they found that some of these ICs may at times emit more soot particles than traditional mud stoves or open-cook fires. The report raises concerns about ICs, which are the leading hope as a clean cooking technology in the developing world.
The researchers measured black carbon emissions from five IC models and traditional mud stoves. They did the test in real homes as part of Project Surya, which quantifies the impacts of cleaner cooking technologies in a village in India. Forced draft stoves burned cleaner than any other IC. However, black carbon concentrations from all ICs varied significantly, even for the same stove from one day to the next.
In a surprise twist, some natural draft stoves occasionally emitted more black carbon than the traditional mud cookstove.
The researchers did not just do a scientific test — they also made sure that the winner of the head-to-head comparison, an IC they call “FD1” in the paper, was distributed to 438 households in the Project Surya area.