by Tim Folger
In one sense, though, it was no improvement at all. The Lorena was good at removing smoke and preventing burns (no small things). It was handsome, easy to use, and helped warm the house. What it didn't do was save fuel—at least compared with a well-tended open fire. Its thick walls, rather than concentrating the heat, absorbed it: the stove warmed the room because it wasn't warming the food. Studies later found that the Lorena used up to twice as much wood as an open fire and took up to three times as long to boil a pot of water. "It sounds funny, but there are still people making Lorenas today," Dean Still says. "They don't understand the difference between insulation and a heat sink."
By the time Still arrived at Aprovecho in the summer of 1989, funding for stoves had dried up. The Lorena, as it turned out, was only one of hundreds of well-meaning but misconceived projects worldwide. There were mud stoves that dissolved in the rain, designer stoves that worked only with a certain pot, portable stoves that fell over when you stirred cornmeal mush on them. In 1983 the Indian government launched a national program that distributed some 35 million stoves across the subcontinent. The units came in various designs from local manufacturers; most were neither sturdy nor especially efficient. Several years later, when a doctoral student from Berkeley surveyed the results in Andhra Pradesh, she found a single stove still in use—as a bin for grain.
"They were good-hearted people," Still says of his predecessors at Aprovecho. "But they were idealistic artists. They were farmers and architects and artisans more than they were engineers." Still didn't seem, on the face of it, much better qualified. Before coming to Aprovecho, he'd worked in a trauma ward in Illinois, lived in a trapper's cabin in Colorado, and served as a security guard on an ocean freighter. He had owned a gas station, worked as a janitor in a synagogue, earned a master's degree in clinical psychology but never used it professionally—"Not one day," he says. Instead, he built a seagoing catamaran with two friends and crisscrossed the Pacific in it. Then he sold the boat, moved to Baja, built a thatched hut by the Sea of Cortez, and stayed there for nine years. "My idea was this," he says. "Can Dean learn to sit under a tree and be contented?"
The answer was no. But his wanderings left him oddly suited to building stoves. He was a skilled carpenter and designer, used to improvising with cheap materials. He was intimately familiar with the needs and hazards of life in developing countries. And he was a born community organizer. His parents, Douglas and Hanna Still, were political activists in the heroic sixties mold. They'd worked with César Chávez in California, the Black Panthers in Chicago, and Martin Luther King, Jr., in the South. (King and Still's father, who was a Presbyterian minister, spent a night in jail together in Albany, Georgia, after a protest.) By the age of thirteen, Dean was tagging along to a civil rights rally in Milwaukee wearing a BLACK POWER T-shirt among crowds of bellowing racists. At sixteen he was among the rioters at the 1968 Democratic National Convention in Chicago, narrowly escaping arrest. His parents always encouraged him to be a freethinker, he says. "So when I was in seventh or eighth grade I told them, 'You're right. School is just a training ground for cogs. I'm going to quit and have adventures.'"
Still was first drawn to Aprovecho by its work in sustainable agriculture and forestry. But it was the stoves that kept him there. Not long after he arrived in 1989, he met a local inventor named Larry Winiarski—a mild, bespectacled, dumpling-shaped man in his forties, perennially clad in overalls. Winiarski had a doctorate in engineering from Oregon State and had worked for the EPA for thirteen years, analyzing the heat discharge from power plants. It didn't take him long to spot the Lorena's inadequacies.
Working as a volunteer, Winiarski sketched out ten principles of stove design and began to build prototypes with Evans and other Aprovecho members. The new devices, which they called rocket stoves, for the powerful roar of their draft, were the physical opposite of the Lorena. They were small and lightweight, so that little heat was wasted on warming the stove itself. They had vertical combustion chambers that acted as chimneys, mixing the wood's vola tile gases with air so that the rockets burned more efficiently. And they had well-insulated walls that forced the hot gases through narrow gaps around the pot, heating it as quickly as possible.
"Larry is one of those rare people in my life, when you ask him a question about stoves he's almost always right," Still says. "He just really, really understands fire." Aprovecho went on to build a number of rocket stoves and to publicize them in books and newsletters, but the group's loyalty still lay with the Lorena. "People were basically ignoring Larry when I showed up," Still told me. "Hippies love earthen structures." The community's open-air kitchen, for instance, was dominated by a clay bread oven that took hours to heat up and consumed great quantities of firewood. With Winiarski's guidance, Still conducted an experiment. Next to the bread oven, he built a simple rocket stove. It was made of a 55-gallon drum, laid horizontally, with a 33-gallon drum inside it and a rocket combustion chamber below. The new stove looked nothing like a traditional bread oven, yet it was hot within fourteen minutes on the strength of a few twigs. An hour later, when the bread was done, the clay oven was still warming up. "That's what won people over," Still says.
Over the next few years, Still and Winiarski built ever more elaborate devices for the community: room heaters, water heaters, jet-pulse engines, wood-fired refrigerators. They were just tinkering, mostly, in the absence of funding for more ambitious work. Aprovecho, by then, was in turmoil. Evans was evicted from the property in the early 1990s after a dispute over the community's finances. Then county inspectors declared the tree house and other structures illegal, and everything had to be torn down, rebuilt, and reorganized. "It was a hippie nightmare," Still says.
To Peter Scott, who came to Aprovecho in 1997, the situation seems not uncommon. "People in environmental communities tend to be escaping from normal society," he told me. "If things were great where they came from, they wouldn't have left. And that sort of opens us up to the pain of the world and what's happening to it. We're all a little crazy, maybe." Scott was twenty-eight when he showed up in Oregon and already a veteran activist. In British Columbia, where he was born, he had stood in front of bulldozers on logging roads, climbed old-growth trees to spare them the axe, and acted in an environmental theater troupe. An article on solar cookers in Mother Jones first led him to Aprovecho, he says—that and memories of a trip to the Congo and the denuded landscapes there. "I'm here to save the forests of Africa by building stoves!" he remembers declaring on his first day. Dean Still just laughed and told him to go pick some vegetables.
Even more than new designs, Still began to realize, stovemakers needed data—to win back their credibility with reliable laboratory and field research. In 2000, when the stove lab was just a toolshed in the woods, Aprovecho built its first emissions detector and began testing Winiarski's designs. By 2004, Still had grants from the EPA and the Shell Foundation to test stoves from other programs. By 2006, when the lab moved to Fred's Island, it had half a million dollars in funding and a staff of scrappy young engineers. (Nordica MacCarty, the lab manager, runs her jury-rigged Datsun on French-fry oil from a local diner. Karl Walter, the electronics designer, once built an airplane by hand and flew it to New York.) The research center now supports itself in good part with sales of microprocessor-controlled portable emissions detectors, designed and built inhouse. The hippie commune has become a quality-control center.
Early in October, Still and I flew to Guatemala to visit the world's longest-running stove study. The village of San Lorenzo, where it's based, is in the remote western highlands, close to 9,000 feet above sea level. It feels like one of the world's forgotten places—its houses, made of mud and straw, cling to terraces that look out over plunging valleys and volcanic peaks—yet its cooks are among the most closely observed in the world. Walk into many local kitchens and you'll find, attached to the walls or in the children's clothes, an array of electronic sensors and transmitters. Some measure particle emissions; others are m
otion detectors or carbon monoxide monitors. Next to the chimney, on top of the stove, is a piece of black duct tape with a small silver disk beneath it. Plug the disk into a Palm Pilot, and it will tell you exactly when and for how long that stove was used in the previous month.
In seventeenth-century England, when a stovemaker wanted to test a new design, he'd soak a piece of coal in cat's urine and throw it into the fire. If the stench went up the chimney with the smoke, the design was deemed a success. Stove-testing is more of a numbers game now: minutes to boil, grams of fuel, milligrams of black carbon. Yet the practical effects of those numbers aren't always clear—especially on the emissions side. "We have no idea how low you have to go before you get the majority of the health bene fits," Jacob Moss told me. "Is it peak exposures you want to get rid of, or is pollution a steady-state thing? Rocket stoves still have a whole slew of emissions that are an order of magnitude higher than EPA standards." Cutting them in half, or even by two-thirds, may not be enough, he said.
The study that Still and I observed was aimed squarely at such uncertainties. Its detectors were the work of Kirk Smith, a professor of global environmental health at Berkeley and one of the world's leading authorities on indoor air pollution. Seven years ago, Smith and a team of students, researchers, and Guatemalan collaborators began tracking more than five hundred local families, all with pregnant mothers or infants less than four months old. The families were divided at random into two groups. Half were given plancha stoves with chimneys; the other half continued to cook over open fires. (After two years, when the first phase of the study was over, the second group got stoves as well.) Every week Smith's team would give the families a medical checkup and download the data from its sensors. In this way, they could track their pollution exposure and its effects in real time. "My wife likes to say that most men spend their lives watching women cook," Smith says. "Her husband has managed to make a career of it."
Smith is a rumpled sixty-two-year-old with tousled gray hair and eyelids as heavy as a basset hound's—he seems both tireless and perpetually short of sleep. When Still and I drove up to his site with him from Guatemala City, he spoke absorbingly, and almost continuously, for six hours about public health. (Last June, for a vacation, he took his wife and daughter to Chernobyl.) San Lorenzo is a six-hour flight plus layover on the red-eye from San Francisco, followed by a vertiginous trek, by truck or multicolored bus, up whipsawing mountain roads. For three years, Smith made the trip every month. His funders left him little choice, he told us.
"I'd go to an air pollution conference and show them my measurements, and they'd say, 'Good Lord, these are orders of magnitude higher than in our cities! And these are the most vulnerable populations in the world. Just go out and fix it!'" Instead of funding stove projects, though, they'd pass him along to the next agency. "So I'd go across the street to the international health meeting," Smith went on, "and they'd say, 'Well, Mr. Smith, you have a pretty convincing problem, but we have seven dollars a year per capita. Do you really expect us to take a dollar out of our budget for vaccines? We need to be damn certain that we can make a difference.'" The pharmaceutical companies had dozens of randomized trials to back up their claims. What did Smith have?
San Lorenzo is his answer. The study, which was funded by the NIH in 2001, now generates so much information that Smith needs two full-time workers to enter it into computers. On the morning after we arrived, Still and I joined the team on their rounds through the village. While Still scrutinized the stoves and suggested ways to improve them (he and Smith were hatching plans for a more efficient "hyper plancha"), I sat and watched the women cook. Diminutive and shy, in their bright embroidered blouses and tapestry skirts, they quietly answered questions as their children clutched their legs or peeked out from behind door frames. The houses were low-ceilinged and bare, with earthen floors, corrugated roofs, and a tree stump or two for furniture. Some had sheaves of Indian corn drying from the rafters or raised eaves that allowed a little light to leak in. A field hand in San Lorenzo makes about twenty dollars a week, Smith said—"Truth be told, they haven't recovered since Cortez." But in most of the houses with stoves, at least the air was clear. In those with open fires it hung so thick and noxious that the walls were blackened, the joists and beams shaggy with creosote. It was like sitting inside a smoker's lung.
Near the end of our rounds, we paid a visit to Angela Jiménez, a small, sharp-featured woman who was part of Smith's original control group. Jiménez is thirty-five and has five children, including four-month-old twins. When we walked in, she was simmering a pot of corn for tortillas and sautéing a recado de pescado—a thin brown sauce made with dried fish and cornmeal, ground together on a slab of volcanic rock. Smith's team had given her a stove six years earlier, but she hadn't bothered to maintain it. The clay tiles and steel griddle were pocked with holes, and smoke was billowing into the room. On the wall behind the stove, the team had hung a poster explaining the dangers of carbon monoxide, but the words were too covered in soot to be legible.
We were getting ready to leave when Jiménez's nine-year-old son, Wilder, lurched in with his baby sister, Milvia, in his arms. She was tightly bundled in blankets, with a blue-and-white knit cap on. Her face was covered in dried phlegm and she was crying hard, with a steady, wheezing cough. Jiménez lifted her up and laid her against her shoulder. Her daughter had been sick for eight days, she told us, and was running a fever. "You should take her to the clinic," Smith said. "Eight days is a long time at that age." Jiménez looked at him with hooded eyes and turned back to the stove. If she went to the clinic, they'd just send her to the hospital, she said. "And that's where people go to die."
Smith later prevailed upon Jiménez to let his team drive her to his clinic, where a physician gave both infants a diagnosis of severe pneumonia. Milvia was hypoxic: her lungs were so full of fluid that they couldn't get enough oxygen into her blood. Her twin brother, Selby, was even sicker: his blood was only 82 percent oxygenated, and his lungs made crackling noises under a stethoscope. "He could pass away tonight," Smith said. Pneumonia is the leading killer of children worldwide, and San Lorenzans are especially susceptible to it. They're so malnourished that their height at eighteen months is already two standard deviations below the norm. And their immune systems are further weakened by the toxins in wood smoke. On average, Smith has found, the children in the village get pneumonia every other year.
"So this is the bottom line," he told me that night, bringing up a graph on his laptop. "This is seventeen years of applying for grants, seven years of research, three and a half million dollars, and me coming down here for a week of every month." Thanks to his electronic sensors, Smith knew his subjects' cooking habits in microscopic detail. He knew when they lit the stove but left the room while it was burning. He knew how much smoke was in the air when they were cooking and how much carbon monoxide was in their breath. And by combining such data with their weekly medical records he could show, for the first time, how the risk of disease increased with exposure—what epidemiologists call a dose-response curve.
"For groups like the Gates Foundation and USAID, the metric is cost-effectiveness," Moss had told me. "How many people are you going to save with a hundred million dollars? That's what they want from this field, and they don't have it yet." Until now. Smith had data on half a dozen diseases that a decent stove could help prevent (it could lower blood pressure about as much as a low-salt diet, for instance). But the most dramatic numbers were for pneumonia. The graph on his laptop had an x axis for exposure and a y axis for disease. In between, the data followed a steeply rising curve. The children who inhaled the least smoke were between 65 and 85 percent less likely to contract severe pneumonia than those who inhaled the most.
"Those numbers are as good as for any vaccine," Smith said. The plancha stoves cost about a hundred dollars each, yet they were a bargain in public health terms. "In our country, we pay forty thousand dollars per year of life saved," Smith said. "Even if you take
the lower end of the benefit, this would cost at most a few hundred dollars per life-year. It's a no-brainer." In a country like India, he and a team of coauthors later estimated in an article in The Lancet, stoves could save more than 2 million lives in ten years.
Smith's data may be good enough for the Gates Foundation, but the harder part will be convincing local villagers. Most of the San Lorenzans liked their stoves and maintained them well enough. But they considered the smoke from cooking more of an annoyance than a threat. (In Africa, some even welcome it as a defense against flies and mosquitoes.) "These kinds of correlations just aren't that easy to make," Smith said. "Think of cigarettes. They kill one out of two smokers prematurely—no war has ever had that effect. Yet famous scientists have died saying there is no connection." To imagine cooking as harmful is an even greater leap. "It's not cyanide," Still said. "They can always think of an eighty-nine-year-old who's been cooking over an open fire all her life. And Grandma's doing just fine."
The best examples of this insouciance in San Lorenzo were the wood-fired saunas that most of the villagers used. The tradition dated back to the ancient Mayans, who would heat rocks over an outdoor fire and carry them into a stone bathhouse. The modern version, known as a chuj, was just a mud-caked hut about the size of a large doghouse. It had an open fire inside, a pallet to lie on, and a blanket to seal the door. A chuj was essentially a human smokehouse, yet the same villagers who swore by their plancha stoves—including Vincente Tema, one of Smith's Guatemalan staff—took sauna baths once or twice a week for half an hour. (The baths were especially good for pregnant women, they said.) When I asked Tema if I could try his chuj, Smith shrugged. I might want to take a carbon monoxide monitor with me, he said.