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Not all that glitters is gold. Especially when it’s tinged with the poison of toxic mercury. On this week’s Curious Climate, co-host Maryam Pasha speaks to the rainforest toxicologist exposing mercury contamination in artisanal gold mining in the Amazon, live at TED 2025. The founding mercury research director at the Centro de Innovación Científica Amazónica (CINCIA) and TED Fellow Claudia Vega partners with miners, healthcare workers, and policy makers, to transform cutting-edge science into tangible solutions to protect gold miners and critical ecosystems.

Created by TEDxLondon
Executive produced by Josie Colter
Produced by Ben Beheshty
Curated by Deesha Chandra
Hosted by Maryam Pasha and Ben Hurst
Communications by Tara Cooper and Issey Gladston

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00:00 Introduction
01:00 Understanding mercury use in gold mining
02:10 Health risks of mercury exposure
03:40 Environmental impact of mercury
05:34 Global implications of mercury pollution
06:12 Artisanal vs. industrial gold mining
08:10 Efforts to mitigate mercury pollution
11:23 Challenges and solutions in mercury mitigation
12:46 Conclusion

[00:00:00] Introduction

[00:00:00] Maryam Pasha: Welcome to Climate Quickies, bite-sized nuggets of Climate Goodness. From our TEDx London experts in under five minutes

[00:00:08] Ben Hurst: in this week’s climate, curious, we are taking a trip into the Amazon rainforest. Claudia Vega [00:00:15] is a rainforest topologist on a mission to expose. And mitigate the hidden dangers of mercury contamination in the Amazon.

[00:00:24] Ben Hurst: In the heart of the Peruvian, Amazon, and the largest illegal gold mining region in [00:00:30] South America, she built a world-class laboratory and research program revealing how unregulated gold mining poisons both wildlife. And indigenous communities through the spread of toxic mercury. By partnering with [00:00:45] miners, healthcare workers and policy makers, Claudia transforms cutting edge science into tangible solutions that protect these critical ecosystems.

[00:00:54] Ben Hurst: Over to Claudia to hear more, stay curious. [00:01:00]

[00:01:00] Understanding mercury use in gold mining

[00:01:00] Maryam Pasha: Today we’re talking to Claudia Vega, who is a rainforest toxicologist.

[00:01:07] Claudia Vega: What do you focus on? Well, I’m focusing Mercury, which is one of the top 10 chemicals of major [00:01:15] concern, but for public health, this is declared by the WHO, so I study Mercury in the, in the Amazon, in the Peruvian, Amazon.

[00:01:24] Claudia Vega: Why I’m studying there is because they have artisanal gold mining in the Amazon. And they use the [00:01:30] mercury to extract the goal. In the Amazon, they have this gold, which is not like rocks. It they have gold in the sediment of the river. Oh. So when they want to extract the gold, they grab the sediment of the river.

[00:01:41] Claudia Vega: And since it’s so little particles, [00:01:45] they have to put mercury. So it bind with the gold. It formed a mix of mercury with gold. Okay. And then they separate the gold from the sand or the sediment. Yeah. And they amalgam, they burn it up and then that gets rid of the mercury

[00:01:58] Maryam Pasha: and leaves the gold. [00:02:00] Exactly. That’s quite interesting.

[00:02:01] Maryam Pasha: So yeah. So they’re using the mercury to kind of, I guess, clump the gold together so they can. Pull it out of the water. More easy or the river more easy or the sediment.

[00:02:10] Health risks of mercury exposure

[00:02:10] Maryam Pasha: But mercury is really poisonous for people. Right. So when you say they’re using it, how like are they? ’cause you can, I mean I remember the idea back, this is like very back in the day, I almost remember it.

[00:02:19] Maryam Pasha: But when you had those mercury thermometers exactly. You were told like this is very, you should be very careful if it breaks, don’t touch it. Like it was like a really big deal to like [00:02:30] be careful around the mercury.

[00:02:31] Claudia Vega: I think in Latin America we were not that aware of that, of of. Of the mercury poison because Yeah, I remember like thinking it was very cool.

[00:02:41] Claudia Vega: The, the mercury drops. When you break the, the thermometer, [00:02:45] there’s no awareness of the risk and that’s what happened with miners there. You tell them that it’s dangerous and one of the answers that they have is like, I have been doing this for 30 years and I’m okay. I’m healthy. What are the risks? With [00:03:00] the miners, they’re probably gonna have, like if they’re breathing the mercury, right?

[00:03:03] Claudia Vega: Right. ’cause mercury is a liquid and it evaporates even though you don’t heat it. Uh, it’s always evaporating. Okay. So they usually breathe the mercury [00:03:15] and. Mercury have neurotoxin. That means I can affect your nervous system. It can give you a variety of effects, can give you headache, it can give, you can start, uh, forgetting things.

[00:03:28] Claudia Vega: Also, you can have shaking [00:03:30] hands. You start shaking without, like controlling when the minor breath also can, could have kidney problems. Yes. So it’s serious. It’s really serious stuff. It’s serious. That’s for the miners.

[00:03:40] Environmental impact of mercury

[00:03:40] Claudia Vega: But also when mercury contaminate. Like the forest and lakes and water bodies, it is transformed.

[00:03:46] Claudia Vega: The inorganic mercury that they use in the, in the mining, it get transformed in the, in the sediment. Mm-hmm. By a bacteria and it’s transformed into organic mercury or methyl mercury. And that form of mercury entered the food [00:04:00] change.

[00:04:00] Maryam Pasha: Oh wow. And it

[00:04:00] Claudia Vega: concentrated in like plants fish. And the fish that eat other fish have higher levels.

[00:04:07] Claudia Vega: And that’s how people could be exposed to mercury. Every day. What makes Mercury such a concern is because [00:04:15] when per, for example, a pregnant woman is eating contaminated fish, it could reach the baby. I. Yeah, and it could affect the brain of the baby so you could have a newborn with disabilities. What

[00:04:28] Maryam Pasha: impacts are you starting to [00:04:30] see from this artisanal gold mining then?

[00:04:33] Maryam Pasha: Locally or globally?

[00:04:35] Claudia Vega: There are local impacts in the Amazon because we did this study where we reduced like the highest level of mercury in a fish in Akin Fisher in the world. Wow. [00:04:45] Yeah, so we ha we collect that sample in a mining concession and it’s like the highest ever register.

[00:04:53] Maryam Pasha: Is it as toxic to like fish as it is to to humans?

[00:04:58] Claudia Vega: That’s a very interesting question because [00:05:00] first I think Mercury has silent toxin because you can be. Expose it and you don’t show the effect immediately and like maybe when you show them it will be kind of late because it builds up in your body, right? It does. You eliminate, [00:05:15] but if you are eating all the time, you won’t

[00:05:17] Maryam Pasha: have time to eliminate.

[00:05:18] Maryam Pasha: Right? Right. Exactly. Yeah. Okay, so obviously it has a impact on the biodiversity in the Amazon where it’s happening and the people I’m assuming, who are relying on. The fish in that [00:05:30] and, and the water in that area, does it have wider

[00:05:33] Claudia Vega: effects as well?

[00:05:34] Global implications of mercury pollution

[00:05:34] Claudia Vega: Yeah, so one of the thing of Mercury is, is an element is like oxygen or nitrogen.

[00:05:39] Claudia Vega: Yeah. So we cannot destroy it. And one thing with mercury is, is the only liquid metal. So that [00:05:45] gives mercury very special property. It can move evaporate, then it can travel in the air in that ra and it can travel long distance. So, to give you an example, in the Arctic, there’s the beluga whale. Yeah. Which is one of the mammals that [00:06:00] have the highest levels of Mercury register.

[00:06:02] Claudia Vega: Oh wow. And. They don’t have direct sources of mercury in the Arctic. Right. But what happened? The mercury can travel and can get places that are far away from where you use it.

[00:06:12] Artisanal vs. industrial gold mining

[00:06:12] Claudia Vega: When you say artisanal gold mining,

[00:06:14] Maryam Pasha: what does [00:06:15] that particularly mean? Is that different than other kinds of gold mining? Is it the use of mercury?

[00:06:19] Maryam Pasha: Is that the difference?

[00:06:20] Claudia Vega: Yeah. Is is the technique, which is mercury, eh, artisan gold mining usually use use mercury and industrial gold mining. They [00:06:30] use cyanide. Oh, but the thing with cyanide is that you can break it and if you have a responsible mining, you could manage cyanide. But with Mercury you cannot break it.

[00:06:41] Claudia Vega: Break it you mean? Like you cannot break it into something else or transform [00:06:45] Mercury, uh, like

[00:06:45] Maryam Pasha: the molecule

[00:06:46] Claudia Vega: itself. Exactly. Oh, interesting. It will be Mercury forever.

[00:06:50] Maryam Pasha: Yeah. These, these mining sites in my mind. Mm-hmm. When I think of a mine, I think of like a big industrial, kind of like complex [00:07:00] thing run by a big multinational company.

[00:07:03] Maryam Pasha: Is that what we’re talking about here?

[00:07:04] Claudia Vega: No, the original name is Artisanal Small Scale Gold Mining. I don’t say small, small scale anymore because I don’t think the ways it is happening ins, which [00:07:15] is where I’m working, is small scale anymore. Interesting. Okay. But the, the technique is very, let’s say, not fancy or sophisticated.

[00:07:24] Claudia Vega: Okay.

[00:07:25] Maryam Pasha: Okay. And so these, but, so I guess also the people doing this that are local people [00:07:30] Yep. Who rely on this kind of

[00:07:31] Claudia Vega: mining for their livelihoods. Exactly. Actually Madrids is one of the places that have more the highest rate of migration. Okay. So people from the south, from the Andes, they go to Madrids to mine.

[00:07:44] Claudia Vega: So [00:07:45] they can get money for livelihood for their families. Yes. Yes. So at the end, I mean, they’re just looking for live Yeah. Livelihood. Yes. Sometimes it’s illegal because there are places in Peru that they can do mining, but there are, most of the places are illegal, [00:08:00] so that’s why we call it illegal gold mining.

[00:08:02] Claudia Vega: In Peru, you can do legal, artisanal gold mining, but in other countries of, of the Amazon is mainly illegal.

[00:08:10] Efforts to mitigate mercury pollution

[00:08:10] Claudia Vega: And so tell me about how your work is like addressing this problem. So. In the institution that I work, which is Amazon Center for Scientific Innovation, we believe that information is power. For example, you told me that you didn’t know about this.

[00:08:23] Claudia Vega: No. Let’s think you like fish. Let’s pretend that you’re an indigenous community. Yeah. And the only thing that you have [00:08:30] to eat in the Amazon is mainly fish. Yes. But if I can tell you that if you choose certain fish, you will be exposed to lower levels. And if you eat other species, you will be exposed to.

[00:08:43] Claudia Vega: Higher levels. Right. So [00:08:45] that’s an information that I can give you and you have a choice to make. Right? Right. So in local level, we work like that. And also we give this evidence, scientific evidence to stakeholders to decision, make it so they can make decision based in science. Right. And not [00:09:00] just something that I feel they are, they are feeling opinions.

[00:09:03] Claudia Vega: Yeah. But something that is based in science

[00:09:05] Maryam Pasha: and, and is it about changing the way this al gold mining is done? Like.

[00:09:11] Claudia Vega: Yeah. We, we are also working on that. Okay. Uh, there are a [00:09:15] group of men that are in mainly women.

[00:09:17] Maryam Pasha: Yeah.

[00:09:18] Claudia Vega: They have this group of artisanal gold mining woman leader. Right. That they’re doing it in a responsible way.

[00:09:25] Claudia Vega: Okay. Because. One thing that we need to understand is not stopping doing mining. That’s not gonna [00:09:30] happen, but we have to make it in a more responsible way. Right? They are using other techniques. They are not using mercury, they’re using, uh, mercury free techniques and they are also like trying to do diversification, right?

[00:09:44] Claudia Vega: Of the [00:09:45] activity. They do other things with mining too. Like for example, I know a, a girl that. Her family has this mining. Yeah. And they also have a resource center next to it. And there’s a place where they know there is gold, but they are not mining [00:10:00] because they know they need to to preserve that. So I think example like that, those are the ones that we have to.

[00:10:07] Claudia Vega: To follow.

[00:10:07] Maryam Pasha: So I’m assuming this gold mm-hmm. Ends up all over the world in products and things, right? I’m

[00:10:14] Claudia Vega: making that assumption. [00:10:15] Is that true? 20% of the gold produces in the world come from artisanal gold mining from any part of the world, right? And in Peru. About 40% of the gold producers in Peru come from artisan gold mining.

[00:10:25] Claudia Vega: Obviously, I’m not

[00:10:26] Maryam Pasha: going around buying gold bars, but like, you know how with like [00:10:30] diamonds there was this certification or you can do lab grown and all this kinda stuff. Is there something with gold that allows you to know that it’s coming from a source that is not polluting?

[00:10:40] Claudia Vega: There isn’t a, a reliable way of trace mercury origin [00:10:45] right now.

[00:10:46] Claudia Vega: Also, we need a, a lot of political willing, right? Like. In the country where it’s produced and also the country that buys it. Right, right. Right. Now, I don’t think there’s like a, a way that, that you can know [00:11:00] fast. Like if it’s certified Mercury, there are some initiative that they’re selling certified Mercury and they look for buyers and they are supposed to pay they, and they pay incentive to the miners, but right.

[00:11:14] Claudia Vega: It’s just a few [00:11:15] ones. Just a small number.

[00:11:16] Maryam Pasha: So one of the things that you were doing was this idea that like the more people know, the better and more informed choices they can make. Yeah, that’s true.

[00:11:23] Challenges and solutions in mercury mitigation

[00:11:23] Maryam Pasha: In terms of like what people might eat, is it also about helping local communities find other work they can do or to do it in a safer way?

[00:11:32] Maryam Pasha: Are you also providing that kind of information?

[00:11:35] Claudia Vega: We. Outreach with the info, the information of Mercury Effect to like to minors, to non non-scientist people to politician. But [00:11:45] that part of the process is a little bit complicated because. If you think about it, like there’s no other job that can give you money so fast, like selling gold, they might not ounce is $3,000.

[00:11:58] Maryam Pasha: That’s a lot just

[00:11:59] Claudia Vega: like that. [00:12:00] So it’s hard to, to find something that is as lucrative as gold as uh, so we try to focus in the, like, you know, the effects in health and maybe the minors don’t feel it because if they’re exposed when they are adults, the effects are [00:12:15] less. Less evident, but maybe their kids are not learning as much as they should be learning.

[00:12:21] Claudia Vega: One, that that’s one part of the equation. And the other part also, and it’s a difficult one, is working with politicians. Because one of the things that the miners say is that [00:12:30] they don’t have support. Like it’s even cheaper to produce illegal gold mining because you don’t have to pay taxes, you don’t have to do a lot of things.

[00:12:38] Claudia Vega: And then legal one. So the problem is very complex and we have to approach it from [00:12:45] different, different point. Yeah.

[00:12:46] Conclusion

[00:12:46] Maryam Pasha: I thank you so much for sharing this work with us. Thank you. I have learned a lot. I love that vision of like the air and the water and the animals being more valuable than gold. Thank you.

[00:12:57] Maryam Pasha: Thank you.

[00:12:59] Ben Hurst: [00:13:00] Thanks for listening to this quickie.

[00:13:01] Maryam Pasha: This episode was created by our superstar podcast team at TEDx London. Until next time,

[00:13:07] Ben Hurst: stay curious.