Senior Research Associate
Dr. Jagannath Biswakarma is an environmental scientist specializing in biogeochemical processes in water, soil and at the interface of soil-water. He combines lab experiments and computational methods to explore nutrient cycling and contaminant dynamics. Passionate about science policy and communication, he focuses on the impact of climate change on water resources, bridging research and environmental legislation.
This Transcript is AI-Generated
Jagannath Biswakarma: If I were to give a number, it's 220 million people are identified at risk of arsenic exposure through groundwater and food. So when you talk about stakes, we are playing with our lives, basically.
Chai: Arsenic exposure poses a serious threat to our health and the environment. But when scientists team up with local communities, they can put simple, effective solutions into action.
Jagannath Biswakarma: We implemented in rural villages a decent- centralized iron nail-based treatment facilities, which very quickly, 60 to 70% of arsenic was eliminated through that filter.
Micah: In this episode, we're exploring what causes arsenic exposure and how methods of monitoring, detection, and treatment save lives.
We'll also look at how iron nail filters could create a surprising circular economy and why this work has inspired a new wave of citizen scientists. I'm Chai Nussbaumer. And I'm Micah Schweizer. This is Balancing the Future from METTLER TOLEDO.
Chai: On this show, we delve into the world of science and technology and explore its transformative impact on our lives.
Micah: Just to start us off, could you give us a brief overview of what arsenic is, and then why does it matter in an environmental and a public health context?
Jagannath Biswakarma: So arsenic is naturally occurring metalloid, by which I mean that we can find it in our planet's crust everywhere, in soil, in rock, in groundwater. Both arsenate and arsenite are toxic.
Arsenic III, which is arsenite, is more toxic than the other one. It can cause cancer, skin lesions to begin with. It can impact a pregnant woman. It can also hinder, uh, neural development in child. So it's quite a dangerous toxic element.
Chai: That's the voice of Dr. Jagannath Biswakarma Biswakarma. He's a senior research associate at the University of Bristol
Micah: If it's naturally occurring, are we worried about the natural occurrence of arsenic, or are we worried about somehow that we are increasing its prevalence?
Jagannath Biswakarma: So distribution of arsenic in soil and water is heterogeneous. It means some part of the globe is mostly exposed to arsenic, which is there in soil. A famous study led by my former colleague showed that sixty percent of geological groundwater in Asia is exposed to arsenic. So this is not contaminated by man-made efforts.
It's only there because of their natural presence. And that leads to ninety-four percent of Asian population exposed to drinking groundwater arsenic contamination. Wow. So basically, I would say in very generalized form that geological, geochemical, geophysical activities discharge arsenic into water and in soils, but also it is coupled with lot of anthropogenic activities like pumping.
We do extract water, which also leads to release of arsenic in soils and in waters beneath our feet.
Chai: And how did you first become interested in studying arsenic in groundwater and also in soil?
Jagannath Biswakarma: That, uh, leads me to my childhood. So I'm from Assam, that's a northeastern state in India. We have Brahmaputra, which is one of the longest river in India.
And I heard about arsenic contamination back then in nineteen nineties, two thousands in Assam because our neighboring state, West Bengal, and neighboring country, Bangladesh, was in hot topic in news media because almost fifty to sixty million people in Bangladesh was, uh, reported to be exposed to groundwater arsenic.
And that was, I'm talking about almost two decades ago. So still it's the case. And fast-forward, I moved to Switzerland, where I did my master's and PhD. So the group I did my PhD with Professor Janet Hering and Dr. Stefan Hug, they are one of the pioneering scientist leaders in arsenic studies. So not only they have discovered how arsenic is mobile in soil and water, they have also come up with, uh, very cost-effective decentralized treatment facilities.
So that also keep me going with arsenic research.
Chai: And you mentioned that sometimes arsenic is naturally, uh, occurring. So what are the main sources of contamination in the natural waters? It was already there in the environment, in the soil?
Jagannath Biswakarma: Yes. So arsenic can be found in soil and in, in groundwater- Mm-hmm
because they are hosted by rocks like, uh, pyrite. Uh, for example, a lot of sulfuric minerals will host arsenic. A lot of iron minerals can also host arsenic. But when these primary rocks go through weathering and dissolution processes, this arsenic can be released in solution, in water, uh, for example, uh, in soil and in-- at the interface of groundwater and soil.
So they are naturally occurring element mostly. But then, uh, with increasing pumping activities, we also disturb the layer beneath our feet, and that disturbance also causes release of arsenic into the soil. And then there are other variables, like for example, in Assam, we have monsoon weather, we have flood, which also changes the environmental conditions.
We have more oxygen-rich conditions in soil and in water. There are some times where we don't have oxygen at all. So based on different environmental conditions, we also see different forms of arsenic and different total concentration of arsenic.
Micah: You mentioned that this was known in the '90s when you were becoming interested in this topic.
Are we understanding the scope better, or do we know what we've already known regarding contamination?
Jagannath Biswakarma: Yeah. So I would probably lead you a bit back in the 1990s. So 1970s to 1990s, there was a shift of using groundwater from surface water for our day-to-day life, uh, for our drinking purposes, for our irrigation purposes.
Before 1970s, it was very rare that we use groundwater for our drinking water as a drinking water source. What happened is that that highly effectively eradicated diseases like cholera, for example. So if we talk about Bangladesh and Vietnam, they got rid of cholera crisis because they stopped using surface water, but then they started depending on groundwater, groundwater extraction, uh, and that leads to unknowingly exposure of arsenic to the rural population.
And so groundwater arsenic contamination is highly studied in last three decades. There are world-renowned groups like Scott Fendorf in Stanford, Janet Haning at Caltech, and then later on at ETH Zurich. Our, uh, EAWAG's, uh, own host group like Water Resource and Drinking Water, they are specialized in arsenic, not only mobility and toxicity studies, but also to understand how we can create decentralized treatment facilities.
So those kind of efforts have been going on for last three decades. In regional level, like for example, in Assam or in West Bengal in India, uh, there are studies going on which tackles how much arsenic is there in soil and in water. What currently I feel is lacking is the integration of this whole data to a model that can predict arsenic mobility in regional scale.
And that is what my research currently going on, that we want to better understand if, for example, there is extreme flood situation, the arsenic concentration, would they remain same? And if it remains same, for example, if the toxicity would also remain same. So I must inform our listeners that toxicity and the availability of the arsenic is not very equal.
It's not directly linked with each other. There are more nuance to this. For example, I mentioned about arsenic III, which is more toxic than arsenic V. So just quantifying arsenic concentration is not sometimes enough. We also need to understand what are the different forms of arsenic present in, uh, soil or in water.
So from groundwater, like for example, we do irrigate as well, and through irrigation, staple crop like rice can also accumulate arsenic, and through rice, through food also now Southeast Asian population are exposed to arsenic. So it's not only a drinking water crisis, it also hinders and impacts, uh, negatively the food quality.
Chai: And I could imagine also some of these foods are exported around the world, so it's not just a localized problem at the locations you mentioned in Asia, but perhaps a broader problem as well.
Jagannath Biswakarma: I'm glad that you brought this issue. Uh, yeah. So these are all transboundary contamination issues. It's not the only regional level Assamese population is exposed to the water.
And so water is more or less directly, indirectly is migrated as well across the globe. So through food like, uh, rice grown in central China, for example, in Colombian population can also be exposed to arsenic. So it is a world-- it's a global crisis. Yeah.
Chai: And can you just give us an idea of how widespread the problem is outside of Asia?
Jagannath Biswakarma: If I were to give a number, it's two hundred and twenty million people are identified as at risk of arsenic exposure through groundwater and food currently. So for example, uh, Southern America is also affected with arsenic contamination in their, uh, groundwater. And then we have, for example, in Korea, South Korea, this arsenic issue is also there.
Netherlands also, they are one of the first one currently in the globe who is fighting to reduce the health safety limit from ten microgram to one microgram because their toxicological studies suggest that if even at ten microgram per liter of arsenic can cause damage. So they are negotiating to bring this down to one microgram per liter.
Micah: That number of 10 micrograms per liter comes from the World Health Organization, or WHO. But many countries don't follow that standard. In fact, 19 countries have no known arsenic regulations at all.
Chai: As Jagannath Biswakarma mentioned, the Netherlands lowered their safe arsenic limit to one microgram per liter in 2020.
This change was driven by a growing concern over long-term health risk, especially lung cancer, which was found to develop at low exposure levels.
Micah: To support the decision, scientists studied a few key areas, the cancer risk from low-level arsenic in drinking water, the cost of healthcare versus removing arsenic, and how arsenic moves through water sources and treatment systems.
Chai: They also examined current and emerging methods to reduce arsenic below the new limit. The findings were clear. Cutting arsenic levels could save the Dutch healthcare system millions of euros each year.
Micah: But how do we even arrive at the data used to make these predictions?
Jagannath Biswakarma: First of all is monitoring, then assessment, and then treatment. So for monitoring, we need regular monitoring and based on seasons. For example, let's talk about home. My home is Titasam. The environmental conditions are so dynamic that we need regular monitoring of our groundwater wells. Those monitoring activities require sophisticated instruments that can analyze the proper concentration, proper level of arsenic, and that's where we need institutional support, a big funding, right?
So lack of, uh, instrument can lead to false quantification of arsenic. So at an individual level, if we're collecting water samples, we need to know where to send those samples so that our samples are quantified and labeled as safe or not safe. So that's a monitoring step. In assessment, we need to know what's the risk associated with that particular concentration of arsenic in that particular region.
Is it linked to the seasonal fluctuations? Is it linked to the climate change? Is it linked to the pumping, or is it linked just to the natural environmental condition? And based on that, we go to the next step, which is treatment. And that treatment brings to the uses of sophisticated membrane filters.
But because we are talking about vulnerable rural population who are economically weaker section, so we need to provide them with a very cost-effective, easy-to-use solutions. And those solutions can be very simple as using iron nails in their water filters. We went to Burkina Faso, for example, in Ouagadougou.
We implemented in rural villages a decentralized iron nail-based treatment facilities, which very quickly, almost sixty to seventy percent of arsenic was eliminated through that filter.
Chai: Wow. It sounds like you've made wonderful strides in research. But how does the system actually work with the iron nail filter?
Can you give us more detail on that?
Jagannath Biswakarma: Yeah, sure. So there are several types of filters. So zero valent iron filters, uh, ZVI. Uh, so we use iron nails, which are locally available. It just has to be unpolished nails because the whole process is very simple. We need to ultimately produce rust nails. So the rust
Micah: is what the arsenic adheres to then?
Jagannath Biswakarma: Yes. So iron is one of the most redox-active element. So we are using iron's property to attract arsenic.
Micah: What does an iron nail-based filter look like?
Jagannath Biswakarma: So imagine a bucket which has, uh, in the bottom layer we have, uh, gravels And then on top of that, we'll have iron nails. Depending on the size of the filter, you can also have the different depth and height of those iron nails.
And on the top of the iron nail, we'll have sand. So the layers are basically iron nails are sandwiched between sand and the gravels So we need to constantly have water flow, for example, to make it effective because switching on and off the filter also will change the iron nails property. So those filters have been used in Bangladesh, in Nepal, uh, in Burkina Faso, and there are studies which shows that almost for seven years, those filters were running effectively, eliminating almost sixty to ninety percent of arsenic from the water.
So there are other filters as well. A lot of, uh, coagulation method people have been adopting and trying. So these filters, like sand-based filtration techniques, have been used as well. So why I am pitching the idea of using zero-valent iron minerals because I have seen my firsthand witnessed the efficiency of those iron filters, and it's also easy to use.
Uh, people just need to have two buckets. Basically, one bucket filled with this whole setup of sand, iron nail gravels, and then other bucket can also be if they want to have another treatment just to get rid of other, uh, like, for example, the rusty iron. If it produces any color to the-- uh, gives color to the water, then it can again go through sand to have better options.
Chai: So the iron nail filter is something you can easily teach a community in a couple hours, different communities all across the world to build themselves.
Jagannath Biswakarma: That's true. My colleague, Anya Bresler, she was in Burkina Faso for almost twice for three years. And in her every visit, she went ahead and trained, uh, the rural population how to use those filters.
And not only to build a filter, but also how to operate, how to do troubleshooting. So capacity building is also a part of wholesome research, uh, because technologies are not cool in the lab. You know, it, it may be fascinating for scientists- Yeah ... but it has to reach to the public. And this kind of cost-effective, decentralized treatment facilities, if it reaches to the public, I think that then solves the purpose.
Chai: That's really phenomenal. Do the nails need to be changed at any point?
Jagannath Biswakarma: Yes. So there are a lot of studies have been going on where we dump the nail now, and storing those rusting nails elsewhere is also a trouble for environment and-- or for public health eventually. So there are a lot of discussions going on currently, and I'm kind of highly advocating to use in our circular economy approach.
For example, arsenic is a widely used dopant in semiconductor industry. So they need pure arsenic to produce, for example, gallium arsenide, uh, for their purposes. So if we can sell arsenic, which we recovered from treating water, to the semiconductor industry, we are basically feeding arsenic into the circular economic approach, and we are-- at firsthand, we are decontaminating water, but then again, we are providing as a resource resource to our industry, which highly dependent on arsenic for their, yeah, production units, basically.
Chai: Turning pollutants into something useful isn't a new idea. For example, scientists have used algae from polluted water to create biofuel and even animal
Micah: feed. Researchers are also pulling nutrients like phosphorus and nitrogen from wastewater and turning them into fertilizer. Some are even engineering microbes that break down toxins and generate electricity, basically turning treatment plants into bio batteries.
Chai: Exciting things are happening, but arsenic pollution is especially tricky because it shows up in different ways and different places and requires multiple approaches.
Jagannath Biswakarma: Gone are those days, I believe, and dare I say so, that one shoe fits all. It has to be tailored. It has to be centric to the environmental climate situation of that particular region. The whole globe is going through dynamic climate and environmental shifts, so we cannot depend on the solution that we are giving, for example, in England to somebody who is there in, in Argentina.
So it is quite challenging, and that's why monitoring and assessment must be mandatory. I would say link it to the-- and you don't have to link it. Like for example, okay, if the Argentinian and Assam situation of arsenic is very similar, then okay, both the places has both, uh, same strategy. But let me give you a high insight.
Assam is sandwiched between Nepal and Bangladesh, and that's corner of India, right? So Nepal's geology is very different. It's, it's full on Himalayas, and we are in Assam, we are at the foothills of Himalaya. So the geology, geochemistry, environmental conditions are not same for Assam and for Nepal. So the distribution of arsenic, the amount of arsenic, the form of arsenic in Nepal and in Assam is nowhere the same So giving a same solution to Nepalese population and to the Assamese population, I don't think we are doing the justice.
And where we are talking about-- when we are talking about water justice, it has to be serving the purpose that, okay, we need to decontaminate. It's not that we have to cost-effectively now, you know, just give a single solution. So
Micah: you've talked about monitoring, assessment, and remediation. Yeah. This sounds like a big job if the mon-- just the monitoring has to be- Yes
really spread across the globe in very specific locations. And then, of course, the results, the assessment and remediation are locale dependent. Mm-hmm. What kind of resources are needed to actually be effective with arsenic remediation if it needs to be so localized?
Jagannath Biswakarma: So luckily, with the last three decades of research, we know that with simulations, with field site sampling, with laboratory studies, with computational modelings, we know different situations, different scenarios where arsenic behaves differently.
So to find out a solution to treat arsenic is no longer a challenge. But the presence of arsenic and its association with different minerals or different compounds are unknown, for example, and that's why I'm focusing more on monitoring and assessment rather than the treatment. So monitoring and assessment, of course, requires a huge lot of resource, and that's where I think we need to, of course, have a defragmented approach, and by which I mean if we have a central policy, for example, for India, like let's say we have a arsenic task force which comes out with a arsenic vision twenty forty, twenty fifty, and within that we have a framework of policy which handles decontamination through monitoring, assessment, and treatment.
And then it also links to the valorization of arsenic because we want to sell those recovered arsenic to the, um, circular industry. So all of this has to be, I think, be taken care of a central government or federal government level. But then they n- also need to focus on capacity building, informing the rural population or even urban population about the topic and different channels, like for example, Ministry of Environment and Forest, Central Groundwater Authority in India, Jal Jeevan Mission.
These three are already different units working for the same purpose, but there is no coherent body which links them all together So fragmented policy doesn't help, and fragmented resource also do not help. So we need to have a central body which act as a bridge between these three. And so it's a very complex and layered issue, I would say, which requires very thorough planning and a single individual from a single discipline cannot take a lead, or it should not take a lead on the whole thing.
So geochemistry, microbiology, environmental scientists, climate change, uh, policymakers, uh, entrepreneurs, innovators, they all need to come together. We focused only on arsenic, which is a contaminant, but there are several other metalloids and heavy metals that are poisonous, that are toxin to water, to food through soil.
So we need a global body certainly which takes care of this kind of discussions and initiate dialogues among different stakeholders.
Chai: When Jaganath talks about other metalloids we need to watch, a few stand out. Lead is found in old paint and is the second most toxic heavy metal after arsenic. It doesn't easily move through soil, but can still be absorbed into crops
Micah: Cadmium is another big risk. It's naturally in soil but gets worse from urban waste, smelting, mining, and synthetic fertilizers.
With so many heavy metals to monitor, setting up a central agency or several could help manage these dangers.
Chai: In the case of arsenic exposure, what are the stakes if we don't get it under control?
Jagannath Biswakarma: We'll have more, uh, severely ill population. Uh, we'll have, uh, dysfunctional newborns. We'll have elder generations whose kidneys are impacted because, uh, so all these heavy metal metalloids like arsenic, it gives a deteriorating health impact, and chronic exposure lead to toxicity, basically.
So kidney failures, like for example, in Assam, the death rates are high. The age that they are dying is also very low. Like for example, if you look at Japan, people, Japanese are like sort of living up to 100 years, 120. In India, we have probably 60 max or, or 70. Honestly, I don't know the average age, but it's very low than Japanese.
We do not consider how environmental factors and contaminants can adversely impact our health. And I think it's high time as a scientist who comes in through science communication to the public, educate them and educate policy makers so that we have a healthy-performing, you know, individuals. So you talk about stakes, we are playing with our lives, basically.
Chai: So where do you think mitigation science is heading? What's the future hold?
Jagannath Biswakarma: So arsenic-related issues are like there are conferences, scientific conferences where people come together working in different discipline. Like for example, I work on environmental biogeochemistry, right? So I look at arsenic speciation, how they flow in soil and water.
But there are communities who, uh, like for example, medical folks on arsenic impact on, like for example, on our health, how kidneys are failing because of arsenic exposure. So different field of researchers are coming together in silos and they are conducting research. They're communicating their research through conferences.
But I think what we are lacking currently is the synthesis of last three to four decades of research And a plan forward because, like, for example, I talk about circular economic approach, we need to have arsenic feed into the semiconductor industries, but that's just the idea that we have, uh, been talking in a small group of people.
So it has to be, you know, spread. I wrote a op-ed, like, for article for a newspaper a few days back, which was published in, uh, in Assam. I gave lot of talks, do podcasts like this just to create awareness, uh, educate public about the effect of, uh, arsenic, for example. So the future, although looks bright, we need to more extensively and urgently work together to synthesize the knowledge and think about the way forward policy.
Micah: Yeah, it's interesting to me that this is one of these areas of research where communication is so critical. I mean, on some level, it doesn't matter what you find out in the lab if that doesn't lead to real-world understanding- Yeah. Yeah ... and changed policy or changed behavior or, or whatever the need is.
Jagannath Biswakarma: Yes, I, I totally agree. I mean, gone are those days where scientists were doing independent individual work in lab, not meeting people, because at least in our field, in environmental sciences field, uh, we need to be able to communicate better to our stakeholders, to our next generations, to the policymakers.
Of course, not everybody are equipped with those skills, but there are platforms where we can adapt, where we can be trained as well, besides our scientific skills. And science communication is also a huge part of engaging with not only rural population, it can also engage with your grandmom. You know, if I were to explain my PhD thesis to my grandma, I should not struggle because we are doing science for our own people.
Uh, clean water, we are, we are talking about clean water. I mean, I'm really sad to mention that clean water is still a luxurious thing that we think. It cannot be, it, it should not be a luxury. It is our fundamental right. So, so communication, I think, is a huge thing that I would highly encourage our next generation of researchers to pursue effectively.
Micah: Any other advice that you would give to, uh, to a young scientist interested in moving into environmental sciences and policy?
Jagannath Biswakarma: I would probably say that be observant, I think, because nature has its own solutions, and we sometimes we just, uh, ignore them. We are not mindful of our surroundings. But science also brings a lot of challenges.
Not every experiment leads to success. Every-- After probably hundred failed experiments, we find a solution. So that also brings to the point of being perseverant. So perseverance is another, I think, virtue that we really require, uh, to succeed in science. But be open, be transparent to the idea. My mom used to tell me that not only confident and secure people can do wonders, and you have to have a risk-taker mindset to create change.
So I think being confident with your own skills, I think that really helps to create, uh, or think of change, and that change need to start within. So, yeah, let's invite and join together in the environmental sciences field to tackle one of the grand challenges that our twenty-first century is facing. Yeah.
Chai: And your mom must be very proud of you indeed.
Jagannath Biswakarma: Thank you. Thank you very much.
Chai: Thank you
Jagannath Biswakarma: for spending your time with us. Thanks a lot. Thank you. It was a pleasure.
Micah: We've been speaking with Dr. Jagannath Biswakarma Biswakarma. He's a senior research associate at the University of Bristol. Kai, what were some of your key takeaways from this conversation?
Chai: Yeah, so the main thing that really stood out is just how damaging the effects of arsenic exposure are. It's so alarming because it pops up everywhere.
Um, it's seen all around the world in crops and other places, and it's really something that communities have started to learn about and see why mitigating it can make a difference. And it's so nice that there's universities and other institutions that actually try to teach local communities to mitigate this and become citizen scientists.
Micah: And one of the things that stood out to me is that in the face of, of what is really a very complex problem, we have, at least for some of the cases, a very simple solution in these iron nail filters. And it's amazing to me that you can take something with resources that are readily available and a little bit of know-how, a community can take this and actually mitigate arsenic exposure in a community.
And so I think this very pragmatic, simple, hands-on approach that's playing out through these collaborations between researchers and citizen scientists and communities, it's really remarkable that something so simple can make a difference.
Chai: Yeah, having a positive impact is not only limited to communities.
As we heard, the concept of selling arsenic-coated nails back to the semiconductor industry is not only innovative, but it's also practical because it's a step in the right direction toward a real circular economy.
This has been Balancing the Future from Medill at Toledo.
Micah: What questions about science and technology would you like answered in a future episode?
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