Using Data Loggers to Reduce Household Air Pollution in Peru

In rural low-income Puno, Peru, residents go through daily life with a serious safety hazard looming overhead. These villagers cook primarily with biomass stoves, which produce high levels of harmful household air pollution (HAP). The problem is global and centuries old: Human beings have been cooking with biomass fuels (wood, charcoal, crop residue, and dried animal dung) since the beginning of recorded history. While people in industrialized countries and urban areas have long since switched to cleaner fuels like electricity and liquid petroleum gas (LPG), nearly half the world’s population – around 3.5 billion people – still rely on biomass. Smoke from biomass cooking contains carbon monoxide, sulfur dioxide, and tiny soot particles that lodge deep inside the lungs. Daily exposure can lead to pneumonia, heart and lung disease and many other health problems. An estimated 3 million people worldwide die prematurely each year as a result of daily exposure to biomass smoke. One critical component of reducing harmful HAP is to encourage biomass users to adopt cleaner fuels such as liquid petroleum gas (LPG).

In Peru, about 80% of the rural population relies on biomass cooking fuel. In Puno, located high in the Andes mountains, the principal source of fuel is cow dung. At an elevation well above 12,000 feet, the air is thinner and the health impact more severe. Studies promoting LPG as a cleaner alternative show that most women prefer gas over biomass, but the high cost puts continuous use out of reach for many.

Developing a potential solution to reduce HAP

Steven A. Harvey, Ph.D., an associate professor at the Johns Hopkins Bloomberg School of Public Health who has worked in Peru for over 20 years, set out to find a solution.

“What if,” Harvey thought, “we could make LPG cheaper by reducing the amount required to meet a family’s cooking needs?”

With students, other faculty, and colleagues from a Peruvian non-profit research organization, Harvey set out to test whether a thermal cooker called the Wonderbag could do the trick. As its name implies, the Wonderbag is just that: a heavily insulated bag that keeps food at cooking temperature for many hours. Users bring their food to a boil, then remove the pot from the stove and enclose it in the bag. By trapping heat, the bag keeps the food at nearly boiling temperature until it is fully cooked. No additional fuel is needed. A soup or a stew that might normally cook for 45 minutes or an hour on the stovetop requires only 10 or 15 minutes instead. As a result, a single tank of LPG lasts much longer than it would if the food were cooked entirely on the stove. Harvey’s study will determine if those savings are enough to make LPG affordable for people who would otherwise have to return to cooking with cow dung.