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Transcript: NICHD Research Perspectives—June 12, 2013

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Announcer: From the Eunice Kennedy Shriver National Institute of Child Health and Human Development, part of the National Institutes of Health, welcome to another installment of NICHD Research Perspectives.

Dr. Roger Glass: Hello, I'm Roger Glass, Director of the Fogarty International Center at the National Institutes of Health, and I'm the guest host for today's podcast from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Thank you for joining us for another in our monthly series of podcasts.

Our topic today is a problem that affects 3 billion people—nearly half of the world's population and a problem which few Americans are aware. Household air pollution from smoky inefficient indoor stoves is the leading cause of death and disability worldwide, mostly in resource-poor countries. This problem affects women and children disproportionately. Cookstoves and open fires used to cook food, boil water, and heat homes are fueled with dung, wood, charcoal, rice husk, or other available fuels. The resulting smoke is released into the homes and is often trapped by poor ventilation. This exposure can pose risks equivalent to a lifetime of cigarette smoking; and use of these stoves is linked to acute pneumonia in children, cardiovascular disease, chronic obstructive lung disease, and lung cancer in adults. It's a serious problem; it's a problem that kills nearly 4 million people a year.

Researchers also suspect that exposure to smoke plays a role in many other health problems, such as low birth weight, asthma, tuberculosis, and cataracts. Along with breathing smoke for hours a day while cooking, many women and girls must walk miles from the safety of their home communities to gather wood, charcoal, or crop residues, which places them at increased risk of a violent attack.

The cause of the problem is readily apparent; solving it won't be easy. It's not just a matter of buying cleaner, more efficient cookstoves and giving them to the people who need them. No, that's already been tried and frequently without checking with community members as to what might fit their needs. People may be accustomed to preparing foods in a certain way and may be reluctant to change. Moreover, each community is different, and what may be acceptable in one community may not be accepted in another. If we in the developed world want to help, then we must conduct the necessary research as to what is acceptable and what really works to reduce exposures and to improve health.

The National Institutes of Health is one of many participants in a partnership to address indoor air pollution resulting from these inefficient stoves. Launched as part of the United Nations Foundation, the Global Alliance for Clean Cookstoves is working to create a global market for clean and efficient cookstoves and clean fuels in the developing world. The Alliance's "100 by '20" goal calls for 100 million homes to adopt clean and efficient stoves and fuels by the year 2020.

Recently, the NIH and other agencies in the federal government hosted an international meeting of experts to lay the groundwork for a future research effort. This resulted in publication in PLOS Medicine in June of this year, entitled "Household air pollution in low- and middle-income countries: Health risks and research priorities."

Now, our first guest today, Dr. William Martin, is NICHD's associate director for prevention research and health promotion. He's the first author of the paper. Our other guests today are Dr. John Balbus of the National Institute of Environmental Health Sciences, Dr. Sumi Mehta of the Global Alliance for Clean Cookstoves, and Dr. Yvonne Njage of our Fogarty International Center here at NIH.

Bill, as the senior author of this paper, could you tell our audience more about the article? What were the main findings? What do you really hope it will accomplish?

Dr. William Martin: Thanks, Roger. The publication of the paper is timely. It's only 6 months after the new report on the global burden of disease in December 2012 in Lancet that noted that the estimated mortality from household air pollution is now almost double the amount from prior reports, accounting for the nearly 4 million deaths per year. Of those deaths, almost half are from cardiovascular diseases such as heart attacks and strokes. The other half, or almost 2 million deaths, will occur mostly from respiratory diseases, such as acute pneumonia in children under the age of 5, whereas you noted chronic obstructive pulmonary disease (more commonly known as COPD) and lung cancer in mostly adult nonsmoking women. Our manuscript also notes other evidence for disease risk associated with household air pollution including birth outcomes such as low birth weight or stillbirths, impaired neurodevelopment such as impaired cognition, asthma in children and adults, risk of tuberculosis, and cataracts that lead to blindness. All of these disease risks are associated closely with the amount of exposure to household air pollution, a topic that will be addressed by Dr. Balbus in just a minute. However, two conditions are not associated with this exposure, but are in fact related to the process of cooking or fuel gathering. Burns and scalds from cooking fires affect mostly, and I would say exclusively, women and children. Everyone knows it happens every day, and yet we have very little information on the prevalence of burns and scalds in low- and middle-income countries.

The other injury risk related to cooking is what you just mentioned, Roger, and that's the need to collect firewood or other types of fuel that require women and children to walk long distances away from the safety of their villages or communities. Both women and children are at risk for violent attacks and death. As we discussed new and improved stove technologies, improved safety is a must to avoid burns, and improved efficiency is needed to reduce the use of fuel, thus reducing the need to collect wood or other fuels as frequently. Most of the manuscript outlines the research priorities and the strategies to achieve these priorities. For example, we know that household air pollution is a major risk for acute pneumonia in children under 5. And this must be addressed if we are ever to succeed in reducing pneumonia deaths to reach the millennium development goal 4 in 2015 by reducing under-5 mortality by two-thirds. But what about the impact of household air pollution on pneumonia neonates or in adults? These studies need to be done. Because of recent studies, we know that household air pollution is a significant risk factor for cardiovascular diseases, accounting for almost 2 million deaths, but we need to demonstrate that the use of improved cooking technologies, with improved stoves and fuels, can prevent these diseases—or at least reduce the risk of dying from the diseases once they occur.

The real research gap that must be addressed is whether clean stoves and clean fuels really works. Can they save lives? In 2011, as reported in Lancet, Kirk Smith and colleagues provided the first hard data from the RESPIRE study in Guatemala that replacing traditional stoves with the more efficient chimney stoves can save lives. In the RESPIRE study, they found if they reduce exposures to household air pollution by at least 50 percent, they can prevent young children from dying from the most severe forms of pneumonia. Our manuscript emphasizes that many more such studies have to be done for acute pneumonia, but also for cardiovascular disease, chronic respiratory diseases, birth outcomes, developmental delays, ocular disorders, and prevention of burn injuries. We recommend approaches that include everything from birth cohort studies, to randomized controlled trials, to perhaps even more timely program evaluation of the major implementation studies around the world, where millions of homes are adopting clean stoves and fuels. As a research community, we need to partner with these implementers to work together. A typical RCT may study hundreds or perhaps thousands of homes whereas major implementation programs can target hundreds of thousands or millions of homes for new stoves or fuels. Are there health benefits or not? How clean must a stove be to save lives? Will a stove that works in an RCT under very controlled conditions have a similar impact when part of a large-scale implementation program? We need to know these answers. But, as will be noted later in this podcast, there are challenges. Human behavior and cultural traditions are deeply embedded in how people cook and how this fits the social constructs within the families and communities. We know that with even the most advanced stoves available, households must use the stoves correctly with the correct fuels such as dried wood and must avoid using the traditional stoves or open fires. Fuel stacking, as this is called, virtually negates the benefits of using an improved stove, as even a partial use of traditional cooking methods will increase air pollution to unhealthy levels. But, on the positive side, manufacturers are used to meeting with their customers and listening to what their needs are. They want to sell their stoves, and they want happy customers. We need to work together—the researchers, communities, manufacturers, and governments—so that the evidence base for improved stoves and fuels can be made stronger for what works and what doesn't. We note in our paper that, in 2012, the Global Alliance for Clean Cookstoves, manufacturers, and others in the cookstove field developed a historic agreement with the International Standards Organization in The Hague, Netherlands. The ISO is sort of an underwriter's laboratory for the world. The agreement lists four tiers of stove performance and that these stoves will be tested around the world and rated by this process. Consumers will finally know what is clean or what is not clean. They will know which stoves will save them fuels and be safe for their families and hopefully provide them with a healthy household environment. This is a wonderful time and opportunity to do research that must be done so that those living in poverty—using biomass or coal to cook their food, to heat their homes, to provide lighting—that they have a chance to adopt new technologies and new approaches including behavioral changes so they can breathe cleaner air in their homes and that they and their children can lead healthier and safer lives. We need the evidence to prove that these stoves achieve these benefits. It is expensive, it takes time, but if not done, we may squander this historic opportunity to finally answer the key questions and to address this global problem, which is the number one environmental cause of death in the world today.

Dr. Glass: Bill, thank you very much. Now, our next guest is Dr. John Balbus, senior advisor for public health at the National Institutes of Environmental Health Sciences. John co-chaired the international meeting with Dr. Martin and also chaired a working group at the meeting that addressed issues of exposure assessment and biomarkers of household air pollution. In other words, to tell if the new stoves are really working properly, we need to find the best ways for determining the levels of smoke within the home, and more specifically, how much of it people actually inhale, referred to as personal exposure monitoring. Now, a "biomarker" is a technical term for a substance—whether a chemical, a protein, or a hormone—that's present in the body after exposure to an environmental factor. "Biomarker" may also refer to changes in the body that predict risk of a specific disease or disease pathway. John, you led this group; please tell us what your group found.

Dr. John M. Balbus: Thanks very much Roger, thanks for the question. In reviewing the literature our working group found that while there has definitely been progress in the use of sophisticated methods to estimate exposures of people living and breathing around cookstoves, more studies, especially using more sophisticated methods, are needed to get a really accurate idea of how clean cookstoves need to be. Cookstove exposures are very variable in time and space because of a number of factors, ranging from the type and wetness of fuel used, to the way people move around their homes, to the way the very homes are constructed and ventilated. So to overcome the challenges in getting accurate results, researchers should consider more investment in nested exposure studies that allow for better characterization of exactly what drives the variability in exposures for particular study setting. The paper also recommends further development and validation of biomarkers for cookstove exposures as you had defined earlier, especially development of biomarkers that provide a good estimate of longer term exposures, and then finally better understanding of the health impacts of cookstoves will be aided by studies that more fully identify and characterize the various constituents of cookstove emissions in different settings and their relative toxicity.

Dr. Glass: So, John, the NIEHS, the National Institute of Environmental Health Sciences, has funded a number of these studies to develop a new generation of equipment for monitoring exposure to smoke. Can you please tell us about these important new, innovative monitoring tools?

Dr. Balbus: Sure. The Exposure Biology Research Program at NIEHS is promoting the development of a whole new generation of exposure monitors for use in research studies. In most of the grants that we have, these projects involve small, lightweight devices that can measure multiple types of air pollutants simultaneously and in real time. Many of them also involve wireless communication to relay information on exposures to recording devices, so we hope that some of these devices will find their way into studies of cookstoves in order to help provide the more detailed exposure assessments that we need to better understand just how clean cookstoves need to be to significantly reduce health impacts.

Dr. Glass: Great, John. Thank you very much. Now our next guest is Dr. Sumi Mehta. She is the director of programs at the Global Alliance for Clean Cookstoves, and she is a really visionary leader for this program. Dr. Mehta, you've worked in this field for many years. The Global Alliance was launched by Secretary of State Hillary Clinton in September 2010. There's been a lot of progress to date. Can you tell us about the Alliance's role in fostering the necessary research to assure that improved cookstove interventions are actually achieving their expected results, and in general, what must be done to improve interventions to really save lives?

Dr. Sumi Mehta: Sure. We at the Alliance are very much aware that building a strong evidence base on the health effects of clean cookstoves and fuels is critical to adoption of clean cooking technologies at scale. Indeed ensuring correct, sustained, and in many cases near exclusive adoption is essential in of itself because, unlike more clinical health interventions such as vaccines, we realize that we don't have a magic bullet to address this issue. On the other hand, the exciting piece is that by focusing on one risk factor, namely household air pollution, we actually have the potential to prevent a wide range of health effects associated with exposure such as the ones that are addressed in the PLOS Medicine paper being highlighted today. The Alliance is going to continue its work to determine exactly how clean is clean enough to ensure health benefits, with a focus on the quick wins or outcomes with short incubation periods, such as child respiratory infections, adverse pregnancy outcomes, and the developmental effects. For example, Alliance-funded researchers in Ghana, Nepal, and Nigeria are actively exploring the links between the adoption of clean cooking technologies and child survival. We will also continue to identify opportunities for linking health research to the scaling up of programs, especially for advanced stoves and fuels. And in doing so, we're extremely excited to strengthen the in-country collaborations with national governments as well as our partners at NIH and CDC. Finally, in addition to managing the Alliance's direct investments, which are by definition somewhat limited compared to the broad sector as a whole, we're going to continue to work with our current and potential donors to raise additional investment for the much larger research agenda that's needed for the sector as a whole.

Dr. Glass: Great. Well, thank you Sumi, this is wonderful. Now, our next guest is Dr. Yvonne Njage, a former member of our team here at the Fogarty International Center. Yvonne is a physician who grew up in Kenya and knows firsthand about how exposures from household air pollution can affect health. Yvonne, what do you see as the principal challenges facing this effort and the opportunities that are needed to advance this program? Do you foresee any problems with these new technologies being adopted in your homeland of Kenya?

Dr. Yvonne Njage: Thank you so much, Roger. As you mentioned, I grew up and I spent the first few years of my life in a three-stone kitchen, and even as of last year, those three stones are still what is being used in the kitchen. So, there's a lot of room to move there. I think as we think about bringing in these new technologies that have a lot of beneficial health effects and other effects as well for women, children, and frankly the entire household, is thinking about what it is that we need to sell the product. So thinking about cookstoves the way a company would think about whether it's detergent or shoes or soft drinks, trying to figure out exactly what it is that the woman in the household values and what barriers there are to change. Just because the stove is good in the lab, does not mean that the woman will use it. So some of the things I think we need to think about as we move forward with these efforts, include thinking about the cultural aspects of cooking and that being the heart of the home, and where many of the woman and the children congregate to talk. There's also the issue of food preferences: there are certain foods that can only be cooked with the three stone or the flavor tastes a little bit different when it's cooked with the three stone. There are dishes that use ash to flavor it, and so when we think about all of those things, everything from the kinds of pots and other utensils that are being used by these women and these societies, we have to keep them all in mind. We have to think almost like the business people who are making products commercially think about: What do we really need to know about this woman to really get her to adopt the stove and use it? And whether we give it to her for free or whether she buys it, in the end, we really need to make sure that she can use it and she values what it's bringing to the home.

Dr. Glass: Yvonne, just help me clarify because I haven't been in a home like this in Kenya. What is a three-stone stove, and how does that compare to what we're talking about for the cookstove alliance?

Dr. Njage: So, a three-stone stove is literally what it sounds like. It is three stones on the ground, and you put the firewood in between and in the holes, so it's an open flame. Where I come from in my village, it is usually encased in a hut, so it's not outdoors, it's indoors. And the last time I was there, I walked in and within 2 minutes my eyes were watering, I could barely breathe, and the whole room was full of smoke. And I compare that to some of the amazing stoves that we've been testing and seeing in action where you can put it in that same room and there is no smoke at all. It's a much better experience in terms of everything from your eyes watering, to coughing, to everything else. But as I said, there are a lot of other cultural things that are imbedded within that three stone that we've all grown up with.

Dr. Glass: And certainly the new stoves are much more efficient, would take less fuel, and ultimately would be would lower the levels of air pollution and be much better for health. So, Yvonne, thank you so much for your description. That brings us to the end of our podcast. I'd like to thank our guests for speaking with us today. I'd also like to thank our podcast listeners for joining us—and for your interest in the work of NICHD to improve the health and well-being of children at home and around the world.

For more information on today's topic and many related topics, do visit the website, That's

I'm Roger Glass, and I hope you will join the staff of the NICHD for more podcasts as they are posted on this institute's website each month. Thank you for joining us.

Announcer: This has been NICHD Research Perspectives. To listen to previous installments, visit If you have any questions or comments, please email


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Last Reviewed: 06/21/2013
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