Cookstoves are a major part of most homes in Asia. Families often use readily available and cheap biofuels, like crop chaff of dung, to prepare their food.
Previous research, mostly based on lab experiments, has shown that smoke emitted from stoves used for cooking and heating, has a definite, detrimental environmental impact, particularly in India.
Despite advances in technology, there are still many people who are reluctant or unable to adopt the newer, cleaner cookstoves. For several years, a team from Washington University in St. Louis, has studied this problem and tried to develop potential solutions. New research has given the team a clearer picture of the stove’s true effect.
"Our project findings quantitatively show that particulate emissions from cookstoves in India have been underestimated," said Rajan Chakrabarty, assistant professor of energy, environmental & chemical engineering at the Washington University's School of Engineering & Applied Science.
The research was the culmination of field studies that were conducted in India by faculty members from Washington University’s School of Engineering & Applied Science and the Brown School. In December 2015, the researchers spent 20 days running a series of tests in Raipur, a city in central India where more than three-quarters of the families use cookstoves to prepare their meals.
Working together with scientists from Pandit Ravishankar Shukla University in Raipur and the Indian Insitute of Tropical Metrology, as well as researchers from the Desert Research Institute in Reno, Nevada, researchers burned a wide variety of biofuels acquired from different parts of India, cooked different meals in a few different ventilation situations. They then recorded the resulting emission levels using high-tech particle measurement devices. When the data was crunched in St. Louis, the results were startling -- in some cases, more than twice the emission levels were detected when compared to the previous lab findings.
"We went out to the rural parts of India to see what was really happening," Chakrabarty said. "Traditional cookstove burning is one of the largest sources of pollutants in India. We found it's a really big problem -- this is revising what people knew for decades."
Further investigation is still needed in order to evaluate the exact effect of cookstove emissions on the climate and health, researchers say their work lays the foundation for further improving the process by which the effects are evaluated and measured.
"We went in with some real advanced instruments to map out detailed information on the emissions," said Pratim Biswas, the Lucy and Stanley Lopata Professor and chair of the Department of Energy, Environmental & Chemical Engineering. "We also used low-cost sensors that we developed. A large number of these could be simultaneously deployed to provide information on the spread of the plume. It's not about taking a single reading."
"This then allows us to eventually determine the regions of hot spots and what locations would have high concentrations," Biswas added. "This detailed characterization of the situation is very critical, and that can only happen in the field. We can't be doing it here in the lab."
The paper on this research was published in Atmospheric Chemistry and Physics