Pham Thi Phuong, 58, cooks in her house in Thuong Phuc Village in Ha Tay Province, just outside of Hanoi, Vietnam. She is among an invisible group of Asians threatened by an environmental hazard rarely considered: indoor air pollution. Photo by Chitose Suzuki: AP

Kirk R. Smith is among the world’s leading authorities on the problem of indoor air pollution. In 2007, the World Health Organization found that indoor air pollution was killing about 500,000 people in India every year, most of them women and children. The agency found that pollution levels in some kitchens in rural India were some 30 times higher than recommended and that the pollution was six times as bad as that found in New Delhi. Globally, more than 1.6 million people per year die premature deaths due to indoor air pollution caused by burning biomass – wood, dung, roots, straw, etc.

A professor of global environmental health at the University of California, Berkeley. Smith has been researching the problem of indoor air pollution since 1981 and he has been working hard to publicize the problem. In 2002, Smith wrote a piece for Science magazine titled “In Praise of Petroleum?” in which he argued that increased use of hydrocarbons, particularly propane and butane, would be an effective – and relatively inexpensive -- way to reduce the numbers of these deaths. Smith earned his doctoral degree from UC Berkeley in biomedical and environmental health in 1977. He has been a member of National Academy of Sciences since 1997.

Kirk R. Smith

RB: I know you’ve done extensive work in Guatemala and India. Are you still working in those countries? Other countries?

KRS: I have worked in a couple dozen countries altogether but my primary work has been in India, Nepal, China, and Guatemala.

RB: The problem of indoor air pollution is clearly important. And yet it doesn’t get as much attention as other health issues like vaccination and safe drinking water and sanitation. Why not?

KRS: Well, it depends of course, on who you talk to. It is getting more attention than it used to. It’s up there in the official estimates. It’s being ranked up there with poor water and sanitation as an environmental risk factor. I think part of the reason, is that air pollution has been associated with power plants, and vehicles and cities. And that’s where original measurements and regulations occurred. But it’s not actually where the highest air pollution levels and where the highest occur.

This is a kind of a forgotten population. The poor women in rural areas of developing countries are about as low on the totem pole, globally, as you can get. They don’t have anybody speaking for them. They don’t have their own Sierra Club or whatever.

RB: In our recent email exchanges, you said that you got a lot of negative comments for your 2002 piece in Science. Can you recall some of those responses?

KRS: I think people, I’d like to think they didn’t read what I wrote carefully or perhaps I didn’t phrase it carefully…LPG [liquefied petroleum gas, i.e., propane or butane] is a very high quality fuel, it’s can be burned cleanly and efficiently with low cost and easily. And so on. Even if you were to substitute LPG for all of the biomass used for cooking in the world, it would have very impact on overall resources. So why ask the poor to take on the need to use fancy, new novel untested, renewable energy devices when we have something that’s good for them? They have many other needs. And this is a great thing for them.

The piece was written about the time of the Johannesburg earth summit or whatever it was called. And they were saying that the poor in Third World areas should only use renewable fuels. And I was saying well, why is that? We have this stuff, why not use it for a high quality purpose?

It’s not to say it would be cheap. Nobody is stepping up to the plate to pay for this. And I must say since 2002, we’ve come to understand even more about how household combustion contributes to climate change. And one of the more interesting and important pollutants now it’s realized to be black carbon -- small soot particles which are extremely harming the atmosphere.

About one-third of the black carbon emissions in the world are from poor household combustion. So you can’t have a black carbon program without considering combustion in households. That is even more benefit to clean combustion. Now that clean combustion could occur with LPG. Of course, it also occur with more efficient biomass stoves that burn the materials more completely and don’t emit any side products including black carbon.

So now I have a two-pronged approach: Push LPG where you can, and that’s usually in the better-off part of the poor population. They are still poor by global standards but better off than the poorest part. And in the poorest part, you are going to have to depend on local biomass resources and try to bring in these advanced combustion stoves that bring emissions down to LPG levels, not quite, but that’s the kind of two-pronged approach.

Now of course, there are efforts to bring liquid or gaseous fuels from biomass. Biofuels -- ethanol, biodiesel, and all sorts of fancy things, and so. They would also burn cleanly in households, but there’s no real activity in that yet. But there is an international LPG industry...

RB: I’ve recently exchanged emails with Emanuel de Merode, the game warden in Virunga National Park about the problem of deforestation in that region and how that deforestation threatens the park’s gorilla population. One of the solutions that de Merode and others have put forward as a solution to the problem is similar to your argument: butane stoves. I know it’s politically unpopular to say it, but it seems to me that you could argue that oil is “green” – or at least it’s greener than many of the alternatives, i.e., dung, tropical wood, etc. Do you agree?

KRS: That’s basically what I said in the Science editorial which offended some people. It’s hard to make a global generalization on the issue of deforestation. In fact, when I talk about it, and I think most of my colleagues, we are careful not to say household use causes deforestation. We say something like it puts pressure on local forests. Most studies show that deforestation is occurring. But that is happening due to agricultural use, forestry, roads, etc…. There aren’t too many places in the world, outside of Africa, where there’s a close link between household fuel use and deforestation. In Africa, there are direct links but it’s mainly through the charcoal fuel cycle, not through the direct use of wood.

The issue there is that charcoal is widely used in Africa. There it pays to cut a forest in the middle of nowhere and the charcoal is high enough density and high enough value that n you can drive the charcoal on a truck 1,000 kilometers and still make money. I never know what to say about charcoal. It’s a very inefficient use of the primary resource. It does lead to pressure on the forest in some places. And it’s also very clean when burned in the house. So it probably has a health benefit in the house. But I think the charcoal fuel cycle in a tradition setting is the most greenhouse-intensive fuel cycle in the world…So it’s a tricky thing, charcoal.

RB: To be clear, that was the problem in Congo: the charcoal producers were cutting wood in Virunga National Park.

KRS: That’s a serious issue. And much of that demand is urban. So there’s some logic to the idea if you could get people to shift over to LPG, it would reduce the pressure. But of course, the local household is going to look at it based on relative prices.

RB: In your 2008 paper, “Wood: The Fuel that Warms you Thrice,” you discuss the problems that various governments have had when trying to provide subsidized LPG to rural areas. How might a subsidized fuel program be made to work effectively?

KRS: We don’t know the answer to that fully. One thing that we’ve learned is that you have to be careful subsidies in general. If you have to be most careful with ongoing subsidies for purchases of things like fuel. On the other hand, if you provide a subsidy for someone to buy an LPG stove and their first cylinder, that’s effective because there’s no other use for it. If you subsidize the fuel, then people will use it in other ways, tractors, trucks, and so forth because the fuel is cheap.

Subsidies are what economists call “leaky.” They don’t help the people you meant to help. Indonesia and India which subsidize lpg a lot, they may be spending more on fuel subsidies than their entire health budgets. I’m all for clean fuel but I’m not sure that’s a good tradeoff. But there are business models, and technologies, like smart cars, and GPS-based cars that are getting to be reliable and cheap enough that you could have a smart subsidy system that wouldn’t be so leaky…These subsidies have a bad reputation and in some cases, that’s rightly deserved. It depends on where the subsidy occurs.

RB: So as you look forward, are you hopeful about your work? How do you see what’s happening?

KRS: In 1990 I was trying to get money for this research from the US EPA. And they said we are interested in indoor air pollution. But we can’t really help in India. It has to apply to Navajos or Eskimos, or somebody in the country. And we went out checked and we found out that we were one generation too late. There wasn’t anybody left using open fires for cooking in the country.

But there was the first flurry of interest in climate change….And they said, at EPA, “well, wait a minute,… greenhouse gas anywhere is a greenhouse gas everywhere.” So we got a grant to do the first measurements of greenhouse emissions and health-related emissions in rural India and China. And that’s still the only systematic database on these things. And that got me into what we now call co-benefits. That is, here’s a way we can achieve two major goals, we can move ourselves toward less climate change and make major improvements in health.

That is now becoming operationalized through carbon offsets. Where you basically get Belgians or the French or Germans to pay for improved stoves because they get carbon credits and the local people get the energy benefits….

We have spun off an NGO from my work. It’s headed by a former student. It’s called Impact Carbon, it has sold the first approved stove program on the international carbon market in April, in Uganda. With exactly this model. In this case, it’s Land Rover that is paying for the carbon credits and it is also getting some good will. And the stoves bought with that money are being used in Uganda and they are saving wood and reducing air pollution, and everybody is winning. It’s a win-win situation. So I’m hopeful. We are now on the trail of a much larger project in China, with the same idea and using 400,000 stoves. Here might be the financial mechanism where a big piece of the cost can be written off and charged to international carbon market. So I’m hopeful, yes.

RB: And how many stoves are being used in Uganda?

KRS: The first round was 30,000. And we are trying to get another 30,000.