Mayan families in Guatemala use indoor fires not only for cooking, but also to keep women and newborn babies warm, said Lisa Thompson, an assistant professor in the nursing school at the University of California-San Francisco. Wood-fired post-partum saunas expose women to carbon monoxide levels as high as 300 parts per million for half an hour at a time, and babies for about 10 minutes – well above the U.S. Environmental Protection Agency’s maximum limit of 35 ppm in a 1-hour period, she said.
Low-weight babies and stillbirths also are linked to the indoor air pollution from solid fuel. In Guatemala, babies were born on average 85 grams heavier if their mothers cooked using electricity or gas instead of cookstoves, according to one study.
Less is known about other hazards. When Smith saw people tossing plastic bags into their cooking fires, he began testing for other toxics and found dioxins, which are carcinogens. Even when people do not burn plastic, he said, incomplete combustion produces toxic substances in many “improved” cookstoves.
“There are thousands of things in wood smoke,” he said. “You get significant emissions of benzene, formaldehyde and butadiene. Do you need to say anything more than that 40 percent of the world’s children are in kitchens where there are significant amounts of three major carcinogens? If you had those three pollutants being pumped into kitchens in this country at the levels that it happens, even with no particles, you’d have the National Guard out.”
Some research also suggests soot accounts for 30 percent of the recent warming in the Arctic, and the UN’s Global Alliance for Clean Cookstoves reports that a quarter of global soot emissions can be traced back to cookstoves.
Because methane, carbon monoxide and black carbon remain in the atmosphere for a shorter time, some scientists and policymakers consider them “low-hanging fruit.” Reducing them with better technology could have an immediate impact on climate change.
Such efforts, however, could be problematic.
Families in Bangladesh would rather spend a hypothetical subsidy on health care, education, electricity or other needs than on low-emission stoves, according to one study. Even a half-price discount did little to increase demand for stoves.
In Lima Bautista’s community, the Peruvian government encourages women to “improve” their open-hearth cookstoves as part of a program that gives families a cash incentive to keep their children in school and take them for health checkups.
But with no technical advice available, many families simply raise the hearth or install an ineffective chimney, said researcher Elizabeth Klasen. Those measures have no impact or could even make emissions worse. Klasen is working with Checkley on a study comparing locally built and commercially available stoves that are meant to increase fuel efficiency and lower emissions.
Smith doubts that they will see a significant improvement.
“I’ve seen so many ‘improved’ stoves come and go that I’m cynical,” he said. “People use the word ‘improved’ as though it’s magical.”
Engineers and development workers have been experimenting with cookstove designs at least since the 1980s. They come in many styles, from mud-brick hearths to oil drums, with the most common model known as a “rocket stove.”
Because lower emissions depend on more efficient combustion, the secret lies in the stove’s combustion chamber, where “time, temperature and turbulence” are key, said Jim Jetter, an engineer in the U.S. Environmental Protection Agency’s Air Pollution Prevention and Control Division.
“The combustible gases have to have enough time to burn in the combustion chamber, they have to have high enough temperature to completely combust, and there needs to be turbulence, or good mixing in the combustion chamber,” said Jetter, who tests cookstoves in his laboratory.
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23 Comments
Add CommentIs there any reason nobody has considered the simple act of exhausting the smoke to the outdoors? Even if the cost of a proper flue is prohibitive, how about locating the hearth near an open window, or maybe a hole in the roof above the fire? DO they really not know any better than to let smoke accumulate indoors? It seems that everyone forgets education and prefers technological solutions. Could that be because of the profit motive? After all, new stoves, or whatever, will have to be designed, built, and sold, putting money in somebody's pocket. While quality of life could be greatly enhanced simply by teaching people how to more safely use the existing technology, there's no money in it so who's going to do it?
Reply | Report Abuse | Link to thisWhile the worst emissions levels from the worst "improved" stove session exceeded the best emissions level from the traditional stove, this does not mean that adoption of improved stoves "may do little to reduce harmful indoor emissions," as the title states. The data show that improved stoves produce generally lower emissions than traditional stoves. While it is true that indoor pollution can be greatly reduced if cooking were done using propane, methane or electricity, this may be an insurmountable leap for people who are now using mud-constructed traditional stoves with no external ventilation, as described in the linked paper (Environ. Sci. Technol., 2012, 46 (5), pp 2993–3000). This may be especially true due to the individual nature of home-constructed traditional stoves, many of which may have much worse performance than the stove used in the test. Do not let the best become the enemy of the good.
Reply | Report Abuse | Link to thisIt would be much more energy efficient to connect them to the grid and give them a $100 microwave. Amazing how greenies are always promoting energy efficiency, but those archaic methods of cooking are terribly energy inefficient.
Reply | Report Abuse | Link to thisFor these folks, a $1.50 stove is a luxury that many cannot afford. A "proper flue," that is a modern metal chimney attached to a stove is not in their budget. Cooking "next to a window" is not going to make much difference, and a "hole in the roof" lets rain in. These people are the poorest of the poor, they don't have a lot of options, but they need something to cook on. Educating them is great, but it doesn't change the physical reality of their world.
Reply | Report Abuse | Link to thisThe price of charcoal (or wood) is a significant cost in the lives of these folks. An improved cookstove can reduce fuel use by as much as 50%, which is roughly analogous to you cutting your power bill (gas+elec) by 50% -- except that at their level of income, the proportionate difference that an expense reduction of that amount makes a much bigger difference in their lives.
Give them a microwave? Are you serious? They don't even have electricity. Their whole families are living on $1.50 per day -- if they are lucky. Giving them a microwave would be a bizarre and enormously ineffective form of "assistance."
A $10 or $20 mass produced solar stove would be a great help for them -- on days when the sun shone, but it won't solve all their needs. It would be beyond their reach unless someone else donated it, and it wouldn't work on extremely cloudy days, but it would help. A similar help would be a small solar hot water heater, but again, they can barely afford a $1.50 improved stove, let alone a piece of equipment that would cost them half a month's wages.
We need to promote and build sustainable, distributed, appropriate technology power sources for these folks. Roughly 2.5 Billion people in the world have no power or almost no power -- they are going to come "online" at some point, and if they do it in a sustainable way, that will save them from making the same damaging CO2 contributions that we in the west have made through our mindless energy gluttony.
We promoted the African ceremic-lined stove made locally from scrap metal. People bought it not for the health or environmental benefits but because it saves money and is more "modern" than the regular stoves. We used advertising to convince some consumers that even though the improved version costs 5 times as much, it pays for itself in a month and lasts over 2 years. It was measured (in actual homes) to reduce charcoal consumption by 46%, and by extension smoke also. Your article has me wondering about black carbon and how much healthier the ceramic-lined stoves are.
Reply | Report Abuse | Link to thisThe WHO and the International Standards Organisation can devise all the standards they want, but I don't see how that will benefit poor households.
Your article hints at a nightmare in which international organizations go around handing out free or subsidized stoves, which will of course be mis-used or not used at all. The real challenge is to convince people that improved stoves or alternative fuels produce enough of the kind of benefits they care about (i.e. financial savings) that they warrant the investment. Only then can you have local suppliers sustainably serving demand from the users themselves. That takes a lot of promotion, which international organizations could support, and not the sort that sounds like public service notifications, but real private sector-style advertising.
One other aspect of helping people implement a sustainable energy lifestyle that Steev touched upon is the demand for fuel that cookstoves place on the local environment. In many places, gathering of fuel (i.e. wood, or wood turned into charcoal) is environmentally detrimental because it results in deforestation, leading to problems with erosion and habitat loss. This is especially the case in areas of very dense population. In India, there are examples of group kitchens that use large solar ovens to cook food for hundreds of people. Providing something like that on a small (individual) scale would be helpful for many people around the world, but they will need financial assistance in order to access the technology (raw materials, transportation, implementation.)
Reply | Report Abuse | Link to thisI agree with what Steev brings up about the disconnect between the theoretical advantages that a product may have and the utility of that product in a given society. Solutions to this problem have to take into account cultural and practical issues. For example: while biogas (animal waste methane) generators are accepted readily in some central asian countries where animals are kept in close confinement (pens), the technology does not transport well to places where people practice herding in open country -- the "poop" is spread out too far to practically collect and use in a home biogas generator. Additionally there are cultural issues that may arise surrounding the handling of animal waste.
The real issue, IMHO, is that some 2.5 Billion people need access to energy to improve their lives, and the best way for them to access that energy (for the planet, and in the long run) is through some kind of appropriate technology sustainable energy program. Of course, we in the more developed countries need to "get our house in order" at the same time.
I teach workshops on how to make solar cookers from scrap. Admittedly it may be hard for some to find reflective material and clear material, both being necessary for any decent solar cooker. But solar cooking will be the permanent solution for most of us, a technology that works today and will still be as cheap and plentiful ten thousand years from now.
Reply | Report Abuse | Link to thisA reliable power grid will be another part of the solution, as well as better combustion of biomass; but I and other critical thinkers have discovered that even in the land of reliable power, solar cooking has many benefits, from cooler kitchens in the summer to more social cooking.
What are the solar cookers like that you build? Webpage? I'm working on converting my school bus (home) to solar heating (as I have time to do things.)
Reply | Report Abuse | Link to thisThe problem with cook stoves in third world countries is more complicated then just cooking food. In most places the cook stove does double duty as the only source of home heating and hot water for bathing and sanitation. An energy efficient cook stove is fine in the tropics but cooking can be done outside under a canopy in tropical climates. For thousands of years Polynesians cooked in communal pits called emus. Cooking was a weekly celebration where everyone help in some way or another.
Reply | Report Abuse | Link to thisIn colder wetter climates this becomes impractical just as cooking with a small efficient wood stove would be. A good example is the hearth that was once the central feature of the early settlers in America. The hearth was built for heating a log cabin or sod house and cooking was a secondary consideration.
Having traveled extensively I can state with conviction that solar cooking would not eliminate the need for q2wSaz
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Where do the real poor in this world live? Mostly in very warm countries. I have lived in "Sunbelt" states exclusively since graduating college. In over 40 years, 90% of my meals have been cooked outside for that reason. Just as in the pre-electrical and pre- air conditioned South. This was not to be "green". Just not to put heat into the house.
Reply | Report Abuse | Link to thisThe grid goes no where near where these people live. They collect and burn whatever grows nearby.
Reply | Report Abuse | Link to thisAnd "Greenies" are not promoting old unhealthy cooking and heating methods like open stoves and coal. At this moment in time people with and environmental outlook and people more concerned with rural development in the poorer south are staring to come together to share experience and offer solutions. New stoves are an important meeting point. Do you understand what I'm writing?
Hi.... TOTORABAMBA, Peru where the lady in the foto lives has a temp range today of 7°C at night and 20°C as the highest daytime temp.
Reply | Report Abuse | Link to thisNot exactly sunbelt I would have thought.
Greenies are promoting whacky energy non-solutions that throw 100's of $billions down the sewer, a small fraction of which could supply electricity to these poor communities. Perfect example is Germany, one of the stupidest places on Earth to install Solar power, and yet Greenies have made it #1 Solar Power country in the World. Take a small fraction of that wasted capital and supply Solar panels and microwaves to these countries with no electricity. Providing cheap electricity is the foundation of building a civilization. It is not a difficult task if you ignore Greenie Religious Dogma and optimize Electricity production according to the local environment. i.e. Nuclear Power for high tech Germany. Solar power for low tech, sunny developing nations. Logical, Rational but the Greenie Religion does not accept that.
Reply | Report Abuse | Link to thisThere are some studies that show a reduction in particulates when stoves are vented properly, but people don't always vent the stoves properly, keep the chimneys clean, use the damper correctly, etc. There are a lot of human variables, as well as technical variables, in cookstove use.
Reply | Report Abuse | Link to thisAccording to the people I interviewed, the ceramic lining isn't as important as the air flow inside the stove - some are more efficient than others. 50% particulate reduction is better than nothing, especially when coal is the fuel, but Smith's point was that the goal should be truly clean indoor air.
Reply | Report Abuse | Link to thisThe WHO and UNDP published this report on energy access in developing countries, and what it would take to expand the grid: http://bit.ly/bC6KJO
Both singing flea and outsidethebox make valid points. In the back-country of Buryatia, a stove is just as much about heat as it is about cooking, while in rural Viet Nam, food production is the main function. And the Polynesian weekly outdoor cooking sounds very similar to neighbors getting together to can food in the US deep South.
Reply | Report Abuse | Link to thisSolar cooking is not *the* solution for folks who don't have access to "modern" gas and electric ranges (or the corresponding utility infrastructures.) It can be a *part* of solution, and it can be a *significant* part of the solution. A self tending solar rice cooker would be a huge blessing for many people in Bangladesh. (Stream of consciousness thought: what if, as a part of it's social welfare programs, the US developed a cottage industry of manufacturing such devices, which would then be distributed as foreign aid; thus, promoting sustainable development abroad, while employing folks here who might not otherwise have work?)
Currently, nearly half the world population has little or no access to distributed power (electric or mechanical.) The standard response in supplying the demand for power is to install generating stations and grids. There have been problems with this approach in some of the less developed countries, where the ability to maintain such an infrastructure is marginal (both from the standpoint of having an educated and technically skilled population, and from the standpoint of endemic governmental corruption.) The investment in infrastructure that is required to supply a diffuse rural population is extremely expensive, and the delivery of power to limited areas in order to encourage urbanization for the sake of minimizing infrastructure costs brings with it another host of problems.
I would argue that a more "sustainable" approach is the development of modules of appropriate technology that could be distributed more quickly and easily than a grid system, and that would not incur the inefficiencies attendant upon grid transmission. This would not necessarily be less expensive, but it also would not, once developed, necessarily be more expensive. The issues of technical training and maintenance would still need solving, but the level of both required, in "lower-tech" systems, would not need to be as high as they would for a grid system.
Such an appropriate technology distributed sustainable power system would, however, be a giant step to reducing the environmental effects of bringing another 2.5 billion people "online."
Sorry for the corrupted post in No.9. I'm not sure how that happened.
Reply | Report Abuse | Link to thisWhat I meant to say was, "Having traveled extensively I can state with conviction that solar cooking would not eliminate the need for indoor stoves in many places.
BTW outsidethebox, millions of poor people do not live in warm countries. Those people who cook indoors on wood or charcoal or even peat and dung live in modern countries too, even America.
"Greenies are promoting whacky energy non-solutions that throw 100's of $billions down the sewer, a small fraction of which could supply electricity to these poor communities."
Reply | Report Abuse | Link to thisYou are confusing electricity with economical energy. Solar is by far the the least expensive way to heat a home and even cook. It is truly astonishing how someone who professes to be a know-it-all about energy has never even heard of passive solar heating. This is the same kind of person that would live in an air-conditioned wood frame house rather then an adobe house with a cement floor in middle of Death Valley.
Nope, I never said anything about passive Solar Heating, which I am a big fan of. The interesting thing if you look at the extraordinary 100's of $billions being dumped into "clean energy", most are going into nutty Scams like Solar PV in cloudy Germany. And unbelievable, actually shutting down their perfectly good, zero emissions Nuclear Power plants to install more idiotic, ultra-high priced Solar PV and Wind Turbines - running at a pathetic 18% CF. Just throwing money down the sewer, money that could provide zero emissions electricity for poor Africans in high Solar areas, and save lives. Win, Win except for the Greenie Cult dogma.
Reply | Report Abuse | Link to thisSo the bizarre thing is, what would actually be economical like Passive Solar Heating and Solar Hot Water is getting ZIP to NIL in subsidies or promotion. The only rationale is that the whole purpose of this Wind & Solar SCAM is to prevent Nuclear Power from displacing fossil fuels for electricity production. Wind & Solar power mates well with Natural Gas not Nuclear or Coal, so the big proponents of Wind & Solar have been Big Oil/NG.
"...Passive Solar Heating and Solar Hot Water is getting ZIP to NIL in subsidies or promotion."
Reply | Report Abuse | Link to thisActually this is a totally erroneous statement. There is many very generous tax benefits available on both the state and federal level for anyone with enough gumption to look into them.
The problem is that 'for profit' corporations that produce the dirtiest and most expensive forms of energy have absolutely no incentive to promote conservation and free energy sources. As long as there is oil and coal to exploit, and as long as big industry invests in ships, trucks and aircraft that run for 30 years on fossil fuel we will be stuck with automobiles that use gasoline too. The fact of the matter is that gasoline is a by product of the distillation process that makes heavier fuels for industry. It's really not safe to burn this fuel in anything bigger then a V8 or a vehicle that needs to carry more then 30 gallons at a time and is driven by amateurs.
The biggest impediment for passive solar for heating and cooking needs is simply that 20th century homes were not designed that way, in spite of visionaries in the mid century. They were stomped to extinction by big business that had other visions for the future when the building booms were in full swing. Housing developers had infrastructure like pipelines and electrical transmission lines to fund for the next 30 years and this infrastructure simple wasn't going to be profitable if homes didn't need huge appetites for the energy. It is ultimately a banker's dilemma. If hindsight were foresight we wouldn't be in this mess, but investment bankers don't concern themselves with profit beyond the terms of their loans.
Now is not the time to defend such wasteful practices anymore, nor is it time to build more waste inspiring energy plants. Now is the time to get behind legislators that that will help get rid of these parasites and get American on the road to self sufficiency in the years to come. It is going to be sink or swim in the very near future and that becomes a personal challenge. Big oil isn't going to help anyone when the oil runs out and the pitfalls of fracking become glaringly obvious.
Passive heating and solar electric for new homes will eventually become law, and it won't be republicans that will figure that out. They will continue to fight it all the way to the bank at least until we all go broke and can't pay the utilities anymore. When that happens, they will be busy peddling all the patents on alternative energy that were bought up by these same corporations years ago.
Unfortunately this is a common problem. Field testing of products is harder and more expensive. Even if a business is conscientious enough to test their products at all (and many are not), lab testing is cheaper and easier. But it does not replicate field conditions, so the results are suspect. Good design is meaningless if the people using the stoves (or any "improved" products) do not use them as the designers intended.
Reply | Report Abuse | Link to thisIt seems obvious to me that open hearth fires are often cleaner because more air can get to the fuel. Stoves block off the air, so unless the design is exceptional, the stoves will not burn as cleanly. There is a solution, not mentioned in the story. Fluidized bed designs force air under the fuel and add both more air and turbulence, insuring hotter, more complete burning. (The same principle allows a blacksmiths forge to get hot enough to melt iron -- or a blast furnace to make steel.) While fluidized bed designs usually use electric motors to force the air, I suspect bellows could be used in places where there is no electricity. Or maybe a solar array could provide electricity -- a fan does not take much power, for a small cook stove, and it would only be needed for an hour or so. Anyway, it seems to me there are more and simpler technology solutions here than trying to install electric or gas fired stoves everywhere -- that is going to be extremely expensive and will not be accomplished any time soon.
Bull. The West has already spent a $trillion subsidy on Wind & Solar Electricity. Show me any significant Solar Hot water expenditure. Good example is Ontario, you could once get $1200 Federal, now expired for Solar Hot water one time payment, but a homeowner can get $186,000 per yr for a Solar PV installation that Ontario doesn't need and is ZERO benefit to Ontario. Passive solar is more difficult since it really would be part of good building design.
Reply | Report Abuse | Link to thisI would have to see some information regarding any efficiency comparison between open hearths vs. traditional cookstoves vs. improved cookstoves. The improved cookstoves claim roughly 50% less consumption of fuel than traditional cookstoves. If that is true, then they are obviously more efficient than regular woodstoves. From reading I have done, I recall (but am not going to the trouble of citing) some UN projects in Thailand where people did actually save substantially on fuel by using an improved stove -- actual, in the field savings.
Reply | Report Abuse | Link to thisI am not aware of any comparisons between an open hearth and a cookstove of any kind (I'm sure they exist, but I haven't seen any.) I *doubt* that an open fire is more efficient than a woodstove, but have no proof of that, either. I know many people still use open fires, but what proportion in relation to those who use cookstoves, I don't know.
However, for folks who are already using cookstoves, not open hearths, the question is one of improving the cookstove. I can think of at least two good reasons NOT to use an open hearth in a house: open fires are easier to fall into, and open fires are more likely to cause a house-fire. Since some folks are already using cookstoves, increasing the efficiency of those stoves makes a big difference for their users.
Passive solar is a hallmark of good building design, I think. But what would be really helpful to someone using a cookstove would be a simple 10 gallon solar water heater and a 10 gallon solar distillation unit. Both are low tech solutions capable of greatly improving life in homes that depend on the kind of cookstoves we have been talking about. Such items are beyond the means of many poor folk, but they are a paltry expense for someone here in the US.