TOTORABAMBA, Peru – Smoke swirls around the hearth and hangs in the sunny doorway of the adobe kitchen where Espirita Lima Bautista crouches by an open fire, toasting barley grains. Soot dangles from the thatch roof in six-inch stalactites, a grim reminder of the particles she inhales whenever she cooks.
For this 80-year-old grandmother, breathing while cooking for an hour is like inhaling the second-hand soot from 400 cigarettes. Although it only lasts as long as the meal is being prepared, exposure began when she was a baby, slung in a blanket over her mother’s back.
Two decades ago, concerns about cooking fires centered on deforestation from firewood. Now research shows that cookstoves can kill people, too.
Indoor smoke from coal, wood or dung – used as cooking fuel by more than 3 billion people worldwide – ranks ahead of unsafe water as a cause of death in low- and middle-income countries. Almost 2 million deaths a year are caused by cooking smoke, which is linked to pneumonia in children, chronic obstructive pulmonary disease, low birth weight babies and lung cancer, according to the World Health Organization.
These fires also help heat up the planet, emitting greenhouse gases as well as the black carbon that creates the stalactites on Lima Bautista’s ceiling
“There are health and climate co-benefits to changing the way a lot of people in rural areas around the world cook,” said Jennifer Burney, a postdoctoral fellow at the Scripps Institution of Oceanography in San Diego who studies the links between energy and food in poor countries.
Faced with global public health threats, governments and non-profit development organizations are encouraging families to install “improved” stoves. The United States has donated $105 million to a United Nations-led effort that aims to put safer cookstoves in 100 million households by 2020. In addition, leaders of the G8 countries pledged in May to take measures to reduce short-lived climate pollutants that include distributing more efficient cookstoves in developing countries.
The problem is that many newer models on the market do little to reduce harmful emissions and some actually make matters worse.
“It’s a case of the policy getting ahead of the science,” said William Checkley, a researcher from Johns Hopkins University’s Bloomberg School of Public Health, who is coordinating two studies in Peru, including a comparative study of cookstoves in Lima Bautista’s village near the Andean city of Ayacucho.
Research published in March points to huge differences between stove models. Black-carbon emissions from some newer stoves were higher than from traditional fire hearths, said Burney, who co-authored the study.
Cookstove research was originally designed to reduce deforestation, said Tami Bond, an engineering professor at the University of Illinois. Now, she said, “health is really the driver” of clean-stove research.
Indoor smoke mainly affects women, children, the elderly and indigenous people, who have the least political and economic clout, and the least access to safe water, sewer systems and health care, said Agnes Soares, environmental epidemiology adviser at the Pan American Health Organization in Washington, D.C.
For many diseases, indoor cooking fires rank between active and passive cigarette smoking as a risk factor, according to Kirk Smith, director of the Global Health and Environment Program at the University of California, Berkeley.
Globally, the World Health Organization attributes 35 percent of chronic obstructive pulmonary deaths and 21 percent of lower respiratory infection deaths to indoor air pollution from solid fuel. In China, where coal is the main fuel, they are the second-highest factor linked to lung cancer, after smoking. Women who cook indoors over open fires also have thicker carotid artery walls and more arterial plaque buildup than urban counterparts who use liquefied petroleum gas stoves, according to Checkley’s preliminary data. Both are signs of heart disease.