You have been doing research on air pollution in Bangladesh for several years. Bangladesh has the most polluted air in the world. However, such pollution exists in several South Asian countries as well. Why did you become particularly interested in air pollution in Bangladesh?
I have been doing research in Bangladesh for more than 12 years now. I first came here as a research assistant, then as a PhD student, and now as an assistant professor.
My first few projects were focused on testing ideas of how to improve specific government institutions and were not related to air pollution. Over the years, I have made lots of friends in Bangladesh and learned a lot about the country.
When I finished my PhD in 2021, I sat down and thought about the biggest problems facing the world that I thought I could improve with my research. That is how I came to start working on air pollution, and since it is such a big problem in Bangladesh, it was natural for me to start working on it here.
A few years ago, you worked on air pollution in Bangladesh. The research was conducted in Mirpur, a neighborhood in Dhaka. There you observed something new — the level of pollution inside our homes is almost the same as outside. This is a novel finding. Please elaborate on this.
Yes, we gave air monitors to more than 500 households in Mirpur and put up two outdoor air monitors. When we compared the readings of the monitors, we found that indoor air pollution was almost as high as the air pollution just outside the same homes. Other research teams have found similar results, so this is now pretty well established.
However, people have a misconception that air pollution is mostly an outdoor problem. I think this is driven by the fact that it is easier to see the haze outdoors than it is to see the air pollution indoors. It is also the case that almost all of the public monitoring stations are outdoors, so that makes it natural for the media to write about air pollution as an outdoor phenomenon.
There are many misconceptions about air pollution in Bangladesh. I have read some of your writings on this. Could you talk about some of those misunderstandings or common beliefs?
Apart from the misconception that air pollution is mostly an outdoor problem, there are several other misconceptions. One is that air pollution is only a problem in urban areas.
It is true that air pollution is a little worse in urban areas, but it is also very high in rural areas. It is literally a problem that affects everyone, rich or poor, rural or urban, old or young, we all have to breathe and we are all negatively affected by air pollution.
Another misconception is that air pollution can be reduced by planting trees or having plants at home. Trees and plants can be beautiful and good for many things, but unfortunately, they do not reduce air pollution in any significant way.
Finally, a fourth misconception is that the concern about air pollution is driven by a concern about climate change. I think that climate change is a real problem that we must tackle at the global level.
However, the reason why I am so obsessed with trying to reduce air pollution is because of the health harms it is causing the population of Bangladesh right now. It is estimated that ambient air pollution causes almost 60 thousand deaths every year in Bangladesh.
That is as many lives lost as 50 Rana Plaza collapses and it is happening every year! I hope that bringing attention to this as well as highlighting some practical solutions, can reduce some of these deaths and improve the health and productivity of the people of Bangladesh.
You have discussed the findings of your research with people from the Department of Environment or other relevant offices. What did they say about your research?
The Department of Environment and the Ministry of Environment, Forestry, and Climate Change are highly aware of this problem and have been very receptive to my research findings. For example, they requested the NBR to cut the taxes and duties on air purifiers earlier this year.
They have a great team working on air quality management, but it is a challenging problem to solve, and it won’t happen overnight. I hope that the research that I am doing can help them focus on the most effective ways to reduce the health harms of air pollution.
There is widespread discussion about air pollution in Bangladesh. But do we yet have an accurate understanding of the sources of pollution? To what extent do you think we are aware of the contribution of each source to the overall pollution?
This is a great question. Unfortunately, the answer is no, we do not have a precise understanding of exactly how much air pollution comes from each source. We know that traffic, brick kilns, power generation, other industries, solid fuel burning for cooking, burning of waste, dust from roads, and construction are all big contributors to air pollution.
However, different studies have come up with different estimates for how large each source is, and there is no clear consensus on this issue. Take the example of how much of Dhaka’s air pollution comes from brick kilns.
Some studies estimate that more than half of the air pollution in Dhaka comes from brick kilns, while other studies estimate that it more like one tenth. One thing I have been pushing for among the community of environmental scientists is to try to reach a clearer consensus on this issue.
From what we generally know, brick kilns, transboundary air pollution, emissions from outdated vehicles, and industrial smoke are the main sources. Government initiatives to control these are very limited. Recently, there has been talk about using air purifiers to combat air pollution in urban areas of Bangladesh. How reasonable is the use of such expensive devices without addressing the root causes of pollution?
I think air purifiers can be an important way that individuals can protect themselves and their families from air pollution. Together with my research team, I tested a relatively cheap air purifier, about 17,000 taka, and it reduced air pollution in a room by 80 per cent.
However, in order for air purifiers to be that effective, windows and the door to the room should be closed. So I think air purifiers are a realistic solution for households at night in the winter, when most of us keep our windows closed.
Nighttime during the winter is also when air pollution is the highest, so if air purifiers can protect us during those hours that is an important improvement. I also think that air purifiers should be installed in schools, hospitals, and other public indoor spaces.
An important caveat is that air purifiers in households is mostly a solution for those of us living in houses where windows can be shut properly. For those living in housing where it isn’t possible to keep the outside air from getting in, like housing made out of tin or where windows cannot be closed shut, air purifiers will not be as effective.
I don’t think there is any contradiction between trying to reduce air pollution at the source and encouraging the population to use air purifiers. We should do both! We should think of air purifiers in the same way we think of water filters.
Of course it would be nice if we could just drink tap water, but now that it isn’t a good idea to drink the water straight from the tap we need to adapt to the situation. Almost every middle-class household I visit in Dhaka has a water filter, but almost no one uses an air purifier.
Air purifiers operate using electricity. That means electricity consumption is a factor. How economically viable is this?
An air purifier is basically just a fan that pushes air through a filter. It doesn’t use more electricity than a ceiling fan or a traditional lightbulb. So it is totally feasible for every household that has uses a ceiling fan when it is hot to use an air purifier when the air pollution is high.
It is important not to confuse air purifiers with air conditioners. Air conditioners use much more electricity, but most models do not purify the air at all; it just makes it cooler.
Air pollution is not something that can be eliminated overnight. Many factors are involved. At present, we do not see much government effort to stop the pollution or its impacts. In this situation, what do you think should be done to combat air pollution?
The government is taking some initiatives to reduce air pollution, and I know that this is a priority for the current adviser Rizwana Hasan. Although progress is slower than we would like to see, I am optimistic that we will see some progress on this issue this upcoming winter.
Here are six actions I believe that the government could take, some of which they are already doing or planning to do:
1. Increase taxes and duties on the most polluting fuels such as coal and diesel. This would also generate revenue for the government and encourage switching away from these fuels.
2. Subsidise LPG cylinders in rural areas so that people use more gas for cooking and less solid fuels like wood. This would also reduce the health harms from indoor air pollution from solid fuel burning.
3. Impose substantial fines on anyone who is caught burning waste, especially within or just outside the big cities.
4. Focus the enforcement of environmental regulation on the most harmful sources, such as brick kilns that are just upwind from the big cities. I am currently assisting the Department of Environment in doing this.
5. Phase out some of the oldest and most polluting buses and trucks. I know the government is working actively on this.
6. Mandate every classroom and hospital room to have an air purifier that must be used during the winter months when air pollution is high.
It is believed that transboundary airflows within the Indian subcontinent play a role in Bangladesh’s air pollution. Officials at our Department of Environment often highlight this as one of the major sources. The impact of such cross-border pollution on Dhaka or Bangladesh’s air quality cannot be denied. But how can effective initiatives be taken in collaboration with neighboring countries to control this pollution?
I don't think transboundary pollution should be a priority for Bangladesh right now. It is true that some of Bangladesh's air pollution it comes from outside of Bangladesh. However, this is not the majority of particulate matter air pollution and since it is much harder for Bangladesh to reduce air pollution from other countries, I believe Bangladesh should prioritising on reducing its own air pollution. It is in every South Asian country's self interest to reduce air pollution and if every country focus on pursuing that goal, there will also be a reduction in transboundary air pollution.
Local particulate matter air pollution is not like greenhouse gas emissions. For greenhouse gases countries need to collaborate to and agree to reduce emissions because each country is only responsible for a small share of the total emissions that affect us all. But for particulate matter air pollution, the majority of pollution comes from within the country's borders, so each country can address most of the problem themselves.
You are an economics teacher. Various studies, including those by the World Bank, have revealed that Bangladesh is suffering huge financial losses due to air pollution. Which segments of society do you think are being affected the most by these losses? Could you please explain some of the methods economists use to calculate such losses?
Broadly, I have seen two types of studies that estimate the economic impact of air pollution (beyond the health impacts). The first type looks at the impact on the productivity of individual workers. These studies tend to show that workers are more productive when there is less air pollution, This has been shown for both manual labor (such a fruit pickers and garment factory workers) and cognitive labor (such as call center workers and chess players). This suggests that air pollution are making us less productive at an individual level, so it is probably also making us less productive as a society.
The second type of study focuses on air pollution's effect on regional GDP and shows that air pollution is associated with lower GDP. These results are consistent with the first set of studies, but it is harder for these studies to exactly pinpoint the effect of air pollution and separate it from other variables. However, both these types of studies typically look at relatively short-run effects from a day up to maybe a year. I don't think we know how large the effects are from the decades of air pollution exposure that people in Bangladesh and other highly polluted countries have experienced.
Regarding which groups in society that are affected the most, I think the simplest answer is that all groups are affected. Everyone breathes and we are all affected when we breathe polluted air. There are probably some differences between different socio-economic groups, but I think the differences are relatively small compared to the overall effects.