Cookstoves in India more polluting than thought: study

Traditional cookstoves, widely used in the rural parts of India, may be producing much higher levels of particulate emissions than previously estimated, causing a detrimental impact on the country's environment and health of residents, a study has found.

The research, published in the journal Atmospheric Chemistry and Physics, was the culmination of field studies conducted in India.

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.

Scientists, including those from Pandit Ravishankar Shukla University in Raipur and the Indian Institute of Tropical Metrology in Pune, burned a wide variety of biofuels acquired from different parts of India, cooked different meals in a number of varying ventilation situations.

They recorded the resulting emission levels using high- tech particle measurement devices.

"Our project findings quantitatively show that particulate emissions from cookstoves in India have been underestimated," said Rajan Chakrabarty, assistant professor at Washington University.

The results were startling, researchers said. In some cases, more than twice the emission levels were detected when compared to the previous lab findings.

"Traditional cookstove burning is one of the largest source of pollutants in India. We found it's a really big problem; this is revising what people knew for decades," Chakrabarty said.

While further investigation is needed to evaluate the exact effect of cookstove emissions on the climate and health, the researchers say their work lays the foundation for further improving the process by which those effects are evaluated and measured.

"We went in with some real advanced instruments to map out detailed information on the emissions," said Pratim Biswas, professor at Washington University.

"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," said Biswas.

"This then allows us to eventually determine the regions of hot spots and what locations would have high concentrations," he said.

"This detailed characterisation of the situation is very critical, and that can only happen in the field. We can't be doing it here in the lab," he said.