WEBVTT - Ep 75 Mercury: The cost of progress 0:00:01.600 --> 0:00:04.000 My love for my husband has become stronger since I 0:00:04.040 --> 0:00:07.480 fell ill with this disease. My mouth quivers so badly 0:00:07.640 --> 0:00:09.960 that I can't touch the food people bring me, so 0:00:10.039 --> 0:00:13.200 I give all my presents to Mohe he's been so helpful, 0:00:13.200 --> 0:00:16.520 you know, so kind. Did I tell you before that 0:00:16.560 --> 0:00:19.440 I am his second wife. We met through a matchmaker. 0:00:19.960 --> 0:00:23.239 I came here from Amakusa. Less than three years after 0:00:23.239 --> 0:00:25.599 we got married, I fell ill with this strange disease, 0:00:26.280 --> 0:00:29.960 such bad luck. I can't even address my kimono. Look 0:00:30.000 --> 0:00:32.839 how I shake. No matter how often I tell my 0:00:32.880 --> 0:00:36.040 body to stop shaking, it won't obey me. I can't 0:00:36.040 --> 0:00:39.240 control my own hands and legs. Whenever he comes here, 0:00:39.400 --> 0:00:42.360 my husband helps me address my kimono, muttering that I've 0:00:42.400 --> 0:00:45.440 become a helpless woman. Once he said I should wear 0:00:45.520 --> 0:00:48.800 underpants because my kimono kept falling in front. So he 0:00:48.840 --> 0:00:51.680 brought me long drawers and helped me into them. As 0:00:51.680 --> 0:00:53.560 he helped me into the pants, I said to him, 0:00:53.720 --> 0:00:57.240 I have really become a helpless creature, My dear, I 0:00:57.320 --> 0:00:59.400 want to get my own body back the way it 0:00:59.480 --> 0:01:02.160 was before. I want to go back to the strong, 0:01:02.280 --> 0:01:05.160 healthy body with which I came into the world. I've 0:01:05.200 --> 0:01:07.640 never been sick, I've never had to stay in bed. 0:01:08.040 --> 0:01:11.000 I was brimming with energy. I could work harder than 0:01:11.040 --> 0:01:14.360 any man. It used to be so lovely out on 0:01:14.440 --> 0:01:17.240 the sea. I want nothing else, just to be like 0:01:17.280 --> 0:01:20.200 I was before I got the strange disease, to be 0:01:20.240 --> 0:01:22.680 able to row a boat and to land a net again. 0:01:23.360 --> 0:01:26.600 I feel so miserable now, a helpless wretch with a 0:01:26.600 --> 0:01:29.800 body like a freak. I can't even wash my underwear 0:01:29.800 --> 0:01:32.800 when I have my period. If I don't work, my 0:01:32.920 --> 0:01:36.280 family won't be able to make ends meet. Minamata disease 0:01:36.520 --> 0:01:39.680 is hell. I feel like I was drifting away from 0:01:39.680 --> 0:01:42.880 this world. I have no grip. I cannot hold my 0:01:42.959 --> 0:01:46.399 husband's hand in mine. My arms shake so hard that 0:01:46.440 --> 0:01:48.920 I can't even draw my own dear son close to me. 0:01:49.880 --> 0:01:51.760 I might even bear this if I could go on 0:01:51.880 --> 0:01:54.880 living somehow. But I can't eat. I can't even bring 0:01:54.960 --> 0:01:57.400 the rice bowl to my mouth. I can't hold my 0:01:57.520 --> 0:02:01.160 chopsticks when I walk. It's not like putting one leg 0:02:01.320 --> 0:02:03.640 in front of the other on the ground, but like 0:02:03.800 --> 0:02:08.639 floating on air. I am afraid. I always get the 0:02:08.680 --> 0:02:11.440 feeling that someone is trying hard to pull me out 0:02:11.440 --> 0:02:15.919 of this world roots and all. I feel so lonely. 0:02:17.040 --> 0:02:20.280 You healthy people have no idea what it's like to 0:02:20.360 --> 0:02:24.920 lie in bed, sick and forgotten by all. My husband 0:02:24.960 --> 0:02:27.520 is the only person I can still rely on. He 0:02:27.639 --> 0:02:30.520 is my only hope. I love him so much that 0:02:30.560 --> 0:02:33.440 I'd give my life for him. God, I wish I 0:02:33.440 --> 0:02:36.000 could use my hands and legs again. I wish I 0:02:36.000 --> 0:02:59.320 could work again like I used to. 0:03:26.080 --> 0:03:28.880 This is going to be a tough episode for so 0:03:29.000 --> 0:03:29.760 many reasons. 0:03:30.400 --> 0:03:30.760 M hm. 0:03:32.160 --> 0:03:36.720 So that was excerpted from a book titled Paradise in 0:03:36.800 --> 0:03:39.960 the Sea of Sorrow by Issimode Michiko. 0:03:40.040 --> 0:03:44.080 And that was a description, of course, of someone suffering 0:03:44.120 --> 0:03:45.760 from minamata. 0:03:45.280 --> 0:03:53.080 Disease right, also known as methyl mercury poisoning. Hi, I'm erin. 0:03:52.920 --> 0:03:55.720 Welsh and I'm erin Alman Updike And. 0:03:55.760 --> 0:03:57.800 This is this podcast will kill you. 0:03:58.640 --> 0:04:01.080 So today we're talking about mercury. 0:04:01.440 --> 0:04:08.480 Mercury. Yeah, it's a very big and very challenging topic 0:04:08.600 --> 0:04:10.360 for a number of reasons. 0:04:10.640 --> 0:04:17.360 Yeah, this listeners, we have been just talking amongst ourselves 0:04:17.480 --> 0:04:20.120 about how much of a challenge this episode has been 0:04:20.320 --> 0:04:25.719 for us. Yeah, the biology has been a real struggle 0:04:25.920 --> 0:04:30.080 trying to not only piece all of the complicated parts together, 0:04:30.120 --> 0:04:31.839 but be able to tell the story in a way 0:04:31.839 --> 0:04:35.880 that makes sense and is like easy for me to explain. 0:04:37.400 --> 0:04:40.599 And I think in both respects, both biology and history, 0:04:40.600 --> 0:04:44.960 the scope is enormous, enormous, and so I think figuring 0:04:44.960 --> 0:04:47.840 out what to concentrate on has been difficult. But also 0:04:48.440 --> 0:04:52.040 like as I did research for this, it was really 0:04:52.240 --> 0:04:57.960 emotionally difficult as well, like its is a very heart 0:04:58.000 --> 0:05:05.240 wrenching and horrifying like disease, while minamata disease specifically, but 0:05:05.680 --> 0:05:08.960 just like the kinds of things that mercury can can cause, 0:05:10.240 --> 0:05:13.679 not all the time, as we will find out, I'm sure, Aaron, 0:05:15.400 --> 0:05:19.039 But yeah, I do think though it'll be a very 0:05:19.040 --> 0:05:24.479 interesting one. This is our second heavy metal yeah yeah. 0:05:24.120 --> 0:05:25.960 But yeah, this will be a very different episode I 0:05:26.000 --> 0:05:27.800 think though than Lead. Yeah. 0:05:27.920 --> 0:05:31.359 Yeah, for sure. Well yeah, but one thing will be 0:05:31.440 --> 0:05:33.240 the same, and that is. 0:05:33.440 --> 0:05:34.680 That it's quarantiny time. 0:05:35.560 --> 0:05:38.039 It is what are we drinking this week? 0:05:38.279 --> 0:05:40.000 We're drinking quicksilver. 0:05:40.480 --> 0:05:44.200 Quicksilver it's the other name common name for mercury. 0:05:44.360 --> 0:05:46.479 Do you know that I did not know that until 0:05:46.480 --> 0:05:50.240 we researched this episode. Really, I had no idea that 0:05:50.240 --> 0:05:53.560 that's what Quicksilver was escape brand to me and a 0:05:53.600 --> 0:05:54.240 surf brand. 0:05:54.800 --> 0:05:57.440 It was a banned from the seventies for me, I 0:05:57.480 --> 0:06:01.560 had I have had my parents old albums. 0:06:02.200 --> 0:06:03.080 Yeah I did not. 0:06:05.240 --> 0:06:06.400 That is hilarious. 0:06:06.720 --> 0:06:09.920 Yeah. Anyways, what's in a Quicksilver It is. 0:06:10.240 --> 0:06:15.000 Vodka, cucumber, lime and a little bit of basil simple 0:06:15.120 --> 0:06:17.960 syrup and a little splash of soda water at the end. 0:06:18.800 --> 0:06:19.880 So refreshing. 0:06:20.480 --> 0:06:23.279 And we will post the full recipe for this quarantini 0:06:23.360 --> 0:06:26.640 as well as the non alcoholic place Brita on our website. 0:06:26.640 --> 0:06:30.400 This podcast will kill You dot com other business. 0:06:30.960 --> 0:06:33.760 We have a website. It's this podcast will Kill You 0:06:33.839 --> 0:06:38.000 dot com yepy. We have so many things there, from 0:06:38.400 --> 0:06:43.360 merch to bookshop dot org to transcripts to all of 0:06:43.400 --> 0:06:46.080 the lists of our sources. We now have a Patreon. 0:06:46.200 --> 0:06:49.440 We have so much available there. Check it out. 0:06:49.839 --> 0:06:57.040 Yeah, do it? Okay, should we get started on this episode. 0:06:56.440 --> 0:07:25.720 We should right after this break. Mercury is an element 0:07:26.480 --> 0:07:31.680 HG also called hydrogorum something like that. 0:07:31.720 --> 0:07:36.440 There are too many like rs in that word. It's 0:07:36.480 --> 0:07:38.680 no wonder that it was changed to mercury to be. 0:07:38.640 --> 0:07:44.040 Honest, and like Aaron's had already also called quicksilver, so 0:07:44.160 --> 0:07:47.760 this is a heavy metal that is naturally found in 0:07:47.800 --> 0:07:53.520 the Earth's crust. However, the majority of this sort of 0:07:53.600 --> 0:07:58.520 bioavailable mercury that we are exposed to as humans has 0:07:58.560 --> 0:08:01.760 been put into the mercury cycle, which we'll talk a 0:08:01.800 --> 0:08:04.840 lot more about very much later in this episode, from 0:08:05.040 --> 0:08:10.760 anthropogenic sources, mostly the burning of coal, which releases mercury vapor, 0:08:10.880 --> 0:08:14.360 as well as gold mining, some various forms of gold mining, 0:08:14.760 --> 0:08:19.760 and a lot of other industrial products. Yep, so mercury. 0:08:19.920 --> 0:08:22.600 I'm sure that everyone is at least vaguely familiar with 0:08:22.640 --> 0:08:26.520 mercury because it is so fascinating to see because it's 0:08:26.560 --> 0:08:30.160 the only metallic element that is liquid at room temperature 0:08:30.200 --> 0:08:32.120 and looks like it's something out of a sci fi film. 0:08:32.400 --> 0:08:38.960 Absolutely totally doesn't look real. But this liquid form of mercury, 0:08:39.080 --> 0:08:42.280 as we'll find out, is certainly not the type of 0:08:42.320 --> 0:08:47.320 mercury that causes the most potential harm to humans or 0:08:47.360 --> 0:08:49.080 even other animals in wildlife. 0:08:49.400 --> 0:08:51.600 Yeah, so I. 0:08:51.559 --> 0:08:54.320 Want to just disclaimer, even though we kind of did already, 0:08:55.320 --> 0:08:57.960 there's a lot to cover when it comes to this 0:08:58.080 --> 0:09:01.280 like nitty gritty of mercury. I hope that I do 0:09:01.320 --> 0:09:06.480 an adequate job. Let us try. So. Mercury comes in 0:09:06.559 --> 0:09:09.920 a number of different forms, and each of these different 0:09:09.920 --> 0:09:14.440 forms has a different level of potential toxicity to humans. 0:09:15.400 --> 0:09:19.520 The three overarching categories of mercury that you can be 0:09:19.559 --> 0:09:26.439 exposed to are elemental or metallic mercury that's quicksilver. Inorganic mercury, 0:09:26.480 --> 0:09:29.359 which is mercury that is bound to like a chloride 0:09:29.559 --> 0:09:32.040 or a nitrite. This is what used to be used 0:09:32.520 --> 0:09:35.120 not to step on your history toes erin, but as 0:09:35.360 --> 0:09:39.640 vermilion many many moons ago. It's like a rock that 0:09:39.800 --> 0:09:43.520 is a color that was used for pigment. That's inorganic mercury. 0:09:43.720 --> 0:09:45.280 Don't worry, I'm not going to talk about it. 0:09:45.440 --> 0:09:50.520 Oh good. And then there is organic mercury. Organic mercury 0:09:50.679 --> 0:09:55.120 is mercury bound to carbon and hydrogen. So these all 0:09:55.160 --> 0:09:59.200 differ in terms of both exposure like how we could 0:09:59.200 --> 0:10:04.640 expose to them, and also bioavailability how much they can 0:10:04.800 --> 0:10:08.720 sort of disperse throughout our body and then cause damage. 0:10:09.720 --> 0:10:13.800 So let's go over the like broad strokes differences between 0:10:13.840 --> 0:10:18.640 these and then we'll talk about how similar they actually 0:10:18.679 --> 0:10:22.240 are once they make it into your body. And then 0:10:22.280 --> 0:10:25.200 we'll go over the symptoms. Kind of organ by organ 0:10:25.400 --> 0:10:30.720 cool sounds good, all right. So elemental mercury aka just 0:10:30.800 --> 0:10:36.680 plane HG. That is the liquid metal, but the way 0:10:36.679 --> 0:10:39.040 that you're more likely to be exposed to it is 0:10:39.080 --> 0:10:42.959 not by that metal itself, but is by mercury vapor. 0:10:44.440 --> 0:10:48.000 So elemental mercury if you ingest it like you swallow it, 0:10:48.000 --> 0:10:51.480 it's really not absorbed very well through the GI tract. 0:10:51.760 --> 0:10:55.320 Something like point zero one percent is one estimate. I 0:10:55.320 --> 0:10:59.200 saw it. Definitely less than one percent is absorbed. Do 0:10:59.320 --> 0:11:04.320 not drink murcury though, But yeah, so elemental mercury vapors. 0:11:04.480 --> 0:11:07.839 It's vaporized very quickly and easily, even at room temperatures, 0:11:07.880 --> 0:11:12.160 but definitely when it's heated, and when it's inhaled, it's 0:11:12.200 --> 0:11:16.320 absorbed very rapidly across your respiratory membranes. Like eighty to 0:11:16.360 --> 0:11:19.920 one hundred percent of it is absorbed across your respiratory membranes, 0:11:20.360 --> 0:11:24.240 and from there it can very rapidly diffuse across other 0:11:24.559 --> 0:11:28.200 membranes in our body, including the blood, brain barrier, and 0:11:28.280 --> 0:11:33.760 the placenta. Additionally, mercury vapor has a relatively long half 0:11:33.840 --> 0:11:37.160 life in our body, about sixty days and so it 0:11:37.240 --> 0:11:39.240 hangs around for quite some time and can kind of 0:11:39.280 --> 0:11:43.600 build up, especially in organs like your brain. M hm. Okay, 0:11:44.240 --> 0:11:48.120 So that's elemental mercury and how we get exposed. Then 0:11:48.160 --> 0:11:50.680 there's inorganic mercury, which I'm not going to talk a 0:11:50.720 --> 0:11:53.760 ton about because it's probably the one that you're least 0:11:53.800 --> 0:11:57.760 likely to be exposed to. But these can be absorbed 0:11:57.800 --> 0:12:01.680 through the skin or the GI track if ingested, but 0:12:02.080 --> 0:12:06.880 only about ten percent of ingested inorganic mercury is actually absorbed, 0:12:07.080 --> 0:12:09.880 so again, it doesn't actually absorb very easily. 0:12:11.040 --> 0:12:13.680 And the fact that it doesn't absorb very easily just 0:12:13.800 --> 0:12:17.880 has to do with like binding, Like what exactly. 0:12:18.280 --> 0:12:21.640 Listen, I asked for you to not ask me these 0:12:21.679 --> 0:12:22.959 difficult questions. 0:12:23.720 --> 0:12:25.240 I'm sorry I couldn't resist. 0:12:25.400 --> 0:12:29.240 But yes, it's essentially that our intestinal membrane doesn't allow 0:12:29.280 --> 0:12:32.080 it to easily pass. And when we get into the 0:12:32.120 --> 0:12:35.160 next one, maybe that will make a little bit more sense. 0:12:35.200 --> 0:12:38.880 Let's get into it, okay, because then there is organic mercury. 0:12:39.880 --> 0:12:41.600 I'm going to spend a little bit more time on this. 0:12:42.600 --> 0:12:47.480 Organic mercury is formed when bacteria in the ocean or 0:12:47.480 --> 0:12:52.720 the soil or our waterways take inorganic mercury, like metallic 0:12:52.760 --> 0:12:56.880 mercury or inorganic mercury ions, And what they do is 0:12:57.160 --> 0:13:00.600 they methylated, which means they add a car carbon and 0:13:00.640 --> 0:13:06.240 some hydrogens. And when mercury is just floating around as 0:13:06.280 --> 0:13:10.520 an ion or as a metal, it's not very bioavailable. 0:13:10.679 --> 0:13:14.360 It's not like attractive for plants or animals, like they 0:13:14.400 --> 0:13:18.040 can't use it when it's just in that form. But 0:13:18.200 --> 0:13:22.160 now all of a sudden, it's connected to a carbon atom. 0:13:22.520 --> 0:13:26.880 Now it's very bioavailable. So this methyl mercury can be 0:13:27.040 --> 0:13:30.440 used by plants, can be taken up by plants, and 0:13:30.480 --> 0:13:34.080 then those plants can be eaten by little fish that 0:13:34.360 --> 0:13:37.559 will hold onto that mercury, and then larger fish will 0:13:37.600 --> 0:13:40.079 eat those fish, and on and on up the food chain. 0:13:40.320 --> 0:13:44.480 And this process is called bioaccumulation, where that mercury stays 0:13:44.480 --> 0:13:46.679 within the system and by the time it makes its 0:13:46.720 --> 0:13:52.000 way up to predatory fish like tuna, sharks, swordfish, or 0:13:52.040 --> 0:13:56.480 other large bodied ocean predators especially, you can have very 0:13:56.559 --> 0:14:00.280 very high levels of this methyl mercury in their mustle. 0:14:00.800 --> 0:14:03.080 Right, which is why there are all those warnings about 0:14:03.080 --> 0:14:05.880 how much can tuna you're supposed to eat and so 0:14:06.080 --> 0:14:09.600 on the whole biomagnification exactly. Question. 0:14:10.360 --> 0:14:11.440 It's going to be a hard one. 0:14:12.120 --> 0:14:18.920 I maybe, okay, why slash? How do bacteria do this? 0:14:19.320 --> 0:14:24.960 Great question? Bacteria are phenomenal in general at making inorganic 0:14:25.080 --> 0:14:28.840 nutrients into organic nutrients and therefore available. That's what they 0:14:28.840 --> 0:14:31.440 do with nitrogen, that's what they do with phosphorus, that's 0:14:31.440 --> 0:14:34.200 what they do with all kinds of different ions. And 0:14:34.240 --> 0:14:35.760 that's the best answer I'm going to be able to 0:14:35.760 --> 0:14:39.560 give you. Oh, okay, okay, but yeah, it's like what 0:14:39.640 --> 0:14:42.560 they do. That's like their point, not their point, but 0:14:42.920 --> 0:14:46.440 that's like a huge part of the contribution of bacteria 0:14:47.160 --> 0:14:49.160 and fungi who do this in the soil as well 0:14:49.640 --> 0:14:53.600 to the sort of nutrient cycling in the environment. So 0:14:53.680 --> 0:14:58.440 that's how methyl mercury exists. And then of course we 0:14:58.480 --> 0:15:01.720 eat a fish and now we're exposed to it. So 0:15:02.000 --> 0:15:06.040 methyl mercury, this organic mercury is by far the largest 0:15:06.080 --> 0:15:10.400 contributor to our general exposure to mercury as humans, not 0:15:10.440 --> 0:15:13.160 only because we're exposed to it through the consumption of 0:15:13.200 --> 0:15:17.880 things like fish, shellfish, et cetera, but also because it 0:15:17.960 --> 0:15:22.280 is almost one hundred percent absorbed through the gi tract 0:15:22.600 --> 0:15:25.240 in addition to potentially being absorbed through the skin or 0:15:25.280 --> 0:15:29.480 inhalation if you were to be exposed that way. So 0:15:29.800 --> 0:15:32.800 it's of the forms of mercury, it's probably the most 0:15:32.840 --> 0:15:37.920 easily absorbed, especially through the GI tract, and once it's absorbed, 0:15:38.040 --> 0:15:41.680 it can very easily and readily distribute it itself throughout 0:15:41.720 --> 0:15:45.520 the body. It can cross the blood, brain barrier and placenta. 0:15:46.080 --> 0:15:47.960 And we'll talk a bit more about how it does 0:15:48.000 --> 0:15:51.960 that in just a minute. And even more concerningly than 0:15:52.480 --> 0:15:55.920 elemental mercury, the half life of methyl mercury in the 0:15:55.960 --> 0:16:01.640 body is longer, it's seventy days or sometimes longer, and 0:16:01.880 --> 0:16:05.680 the way that it's excreted is different. So it's excreted 0:16:05.760 --> 0:16:08.480 in our feces, it has to be conjugated in our 0:16:08.520 --> 0:16:11.760 liver and then we have to poop it out, whereas 0:16:11.800 --> 0:16:15.440 other forms of mercury, like inorganic and elemental mercury, we 0:16:15.520 --> 0:16:19.520 actually excrete in our urine. Huh, Yeah, isn't that interesting? 0:16:19.720 --> 0:16:21.200 That's very interesting. 0:16:22.920 --> 0:16:25.880 So that's all the different sort of forms of mercury 0:16:26.240 --> 0:16:28.640 and how we get exposed to them, and the difference 0:16:28.720 --> 0:16:32.080 is in how much of the mercury you're exposed to 0:16:32.320 --> 0:16:36.120 is going to actually make it into your body. I 0:16:36.160 --> 0:16:38.840 will also note there's a lot of other forms of 0:16:38.920 --> 0:16:43.000 organic mercury besides methyl mercury, some of which are even 0:16:43.120 --> 0:16:48.200 more toxic, like die ethyl or dye methyl mercury. Yeah, 0:16:48.400 --> 0:16:53.240 but in general, in fish, for example, by far, the 0:16:53.280 --> 0:16:55.360 most common one that you're going to be exposed to 0:16:55.400 --> 0:16:58.640 is methyl mercury. That's what is most common in the environment. 0:16:59.200 --> 0:17:01.800 The other forms, and to be produced in industrial settings 0:17:01.880 --> 0:17:04.160 rather than by bacteria in the environment. 0:17:04.440 --> 0:17:05.320 Okay, gotcha? 0:17:07.400 --> 0:17:10.480 All right, So now that we know all that, what 0:17:10.600 --> 0:17:13.760 does that actually look like when this mercury does get 0:17:13.800 --> 0:17:16.800 into our bodies? What happens and why does it make 0:17:16.880 --> 0:17:20.120 us so sick? So again, here there's a lot of complication, 0:17:22.920 --> 0:17:27.560 And what I'll say upfront is that if anyone remembers 0:17:27.600 --> 0:17:31.200 our lead episode, a lot of the mechanisms of how 0:17:31.200 --> 0:17:36.520 mercury causes toxicity are not very dissimilar to lead. But 0:17:36.640 --> 0:17:39.840 the difference was that in lead, there's like kind of 0:17:40.000 --> 0:17:44.800 one very compact story, like lead binds to a specific 0:17:45.000 --> 0:17:50.680 enzyme that then blocks heme synthesis and causes anemia. With mercury, 0:17:51.080 --> 0:17:55.200 because of what it does, it has a much broader effect, 0:17:55.520 --> 0:17:59.720 and therefore it's more difficult to pinpoint the precise mechanism. 0:17:59.800 --> 0:18:03.320 If that makes sense of toxicity, Yes, so I'm just 0:18:03.359 --> 0:18:05.199 gonna kind of look at the broad strokes and I 0:18:05.240 --> 0:18:09.760 think that we'll understand a lot of it. So in 0:18:09.800 --> 0:18:12.360 all of the various forms, once you're exposed to mercury, 0:18:12.400 --> 0:18:16.320 once it gets into our bodies, it generally exists as 0:18:16.440 --> 0:18:21.439 a positively charged ion, a cat ion. So either HG 0:18:21.680 --> 0:18:26.080 plus or HG two plus or even methyl mercury itself 0:18:26.200 --> 0:18:31.640 is a positively charged molecule. And because it's positively charged, 0:18:31.840 --> 0:18:35.600 like all positively charged ions, they have an affinity for 0:18:36.040 --> 0:18:41.119 negatively charged things in our body. That means proteins and 0:18:41.160 --> 0:18:46.639 some amino acids. Uh so yeah, oh is right, and 0:18:46.720 --> 0:18:49.240 so that's lead does the same thing. Lead exists as 0:18:49.280 --> 0:18:52.760 a positive ion and binds to certain proteins. In the 0:18:52.800 --> 0:18:58.000 case of mercury, though, mercury has a strong affinity for 0:18:58.640 --> 0:19:04.040 proteins and amino appaids that contain two different types of residues, 0:19:04.160 --> 0:19:09.440 sulfur groups which are called thiols and selenium groups, which 0:19:09.440 --> 0:19:14.080 are called selenols. So there's two big problems with this number. 0:19:14.160 --> 0:19:18.920 One there are some amino acids, like, for example, cystine, 0:19:19.760 --> 0:19:23.800 which is an amino acid with two sulfurs that when 0:19:24.200 --> 0:19:30.640 methylmercury binds to cystine, it looks like another amino acid, 0:19:30.960 --> 0:19:36.919 methionine that's a neutral amino acid and is not just 0:19:37.160 --> 0:19:41.560 able to cross barriers, but can be actively transported across 0:19:41.560 --> 0:19:45.359 barriers like the placenta and the blood brain barrier, okay, 0:19:45.960 --> 0:19:50.080 by amino acid transporters. So not only can this ion 0:19:50.200 --> 0:19:55.359 itself potentially cross these barriers once it connects with cysteine, 0:19:55.440 --> 0:19:59.000 it can be transported like oh hey, you look like methionine. 0:19:59.119 --> 0:20:01.960 Come on over, we're going to use you to build 0:20:01.960 --> 0:20:04.119 this fetus, or we're going to use you and like 0:20:04.160 --> 0:20:05.920 deposit you in the brain right now. 0:20:06.400 --> 0:20:07.200 Oh my god. 0:20:07.240 --> 0:20:12.879 So that's yeah, that's bad. The other thing, so, because 0:20:12.920 --> 0:20:15.240 that kind of tells us that's how it gets into 0:20:15.280 --> 0:20:18.000 these structures, what does it do once it's there? Like, 0:20:18.080 --> 0:20:21.679 why is that so bad to have mercury instead of 0:20:21.720 --> 0:20:27.080 actually methionine By binding two not just cysteine, but a 0:20:27.359 --> 0:20:31.280 number a whole suite of proteins, amino acids, and enzymes. 0:20:32.280 --> 0:20:37.080 What mercury does is it causes a cascade of downstream effects. 0:20:37.160 --> 0:20:41.920 It basically blocks interrupts the actions of these various enzymes 0:20:42.240 --> 0:20:45.360 or proteins. And like I said, it's not just one, 0:20:45.440 --> 0:20:48.480 it's not just cysteine. There's a whole bunch of enzymes 0:20:48.960 --> 0:20:53.720 that have either sulfur or selenium groups on them. So 0:20:53.880 --> 0:20:58.000 one of the principal effects seems to be that an 0:20:58.040 --> 0:21:03.959 increase in mercury leads to a decrease in the antioxidant 0:21:04.040 --> 0:21:07.240 ability of our body. So a lot of the damage 0:21:07.240 --> 0:21:12.080 that occurs in mercury toxicity is due to reactive oxygen species. 0:21:13.400 --> 0:21:19.359 So basically, mercury is blocking enzymes that normally help fix 0:21:19.800 --> 0:21:22.960 oxidative damage, and it blocks their ability to do so 0:21:23.040 --> 0:21:25.800 it's like boop, you can't fix this. And so now 0:21:25.800 --> 0:21:30.400 there's just this free floating reactive oxygen that can cause 0:21:30.400 --> 0:21:32.760 a lot of damage. And when you combine that with 0:21:32.800 --> 0:21:35.879 its ability to cross these important membranes like the blood 0:21:35.880 --> 0:21:40.280 brain barrier and the placenta, you get oxidative damage in 0:21:40.359 --> 0:21:42.840 structures that can't easily be repaired. 0:21:43.480 --> 0:21:45.639 That makes a lot of sense. 0:21:46.280 --> 0:21:49.680 I'm glad because it took me a long time to understand. 0:21:49.600 --> 0:21:52.439 The I mean, it's really complicated and like, these are 0:21:52.480 --> 0:21:55.639 things I haven't thought about, like oxidative stress, and I 0:21:56.000 --> 0:21:59.000 on is like that's nitty gritty, but that's very and 0:21:59.040 --> 0:22:02.880 so this is just this is just because the mercury ion, 0:22:03.840 --> 0:22:08.240 once it's in you, is attracted too. It's binding to 0:22:08.440 --> 0:22:11.919 these negatively charged things and sort of replacing their function 0:22:12.080 --> 0:22:15.000 or preventing them from from functioning the way they should. 0:22:15.560 --> 0:22:19.679 Okay, precisely exactly, yeah, exactly, and it can do that 0:22:19.760 --> 0:22:24.560 on so many different sort of proteins and enzymes. Yeah, 0:22:24.600 --> 0:22:25.600 so it's very bad. 0:22:25.800 --> 0:22:28.920 And so this is why systemic. 0:22:29.240 --> 0:22:32.360 Systemic and why so many of the symptoms like we'll 0:22:32.359 --> 0:22:35.800 see are neurologic, right, because once it gets into the brain, 0:22:36.040 --> 0:22:38.560 it can kind of just stay there for quite some time, 0:22:39.800 --> 0:22:45.399 bound to these proteins and enzymes. So the symptoms in 0:22:45.480 --> 0:22:48.720 some ways do depend on the form of mercury that 0:22:48.840 --> 0:22:53.320 somebody is exposed to, but what they really depend on 0:22:53.440 --> 0:22:57.080 is where that mercury goes and potentially accumulates. And so 0:22:57.560 --> 0:23:00.560 that also depends on whether the exposure is a whole 0:23:00.560 --> 0:23:05.000 bunch of mercury all at once, like acute toxicity, or 0:23:05.080 --> 0:23:07.840 a smaller amount of mercury over a longer period of 0:23:07.880 --> 0:23:12.160 time or chronic toxicity. So I'll kind of go through 0:23:12.320 --> 0:23:17.000 very briefly system like, organ system by organ system, because 0:23:17.760 --> 0:23:20.760 since we're exposed to these different forms of mercury in 0:23:20.800 --> 0:23:25.760 different ways, they tend to have most effects on certain organs, 0:23:25.800 --> 0:23:30.120 if that makes sense. But the truth is that any 0:23:30.160 --> 0:23:33.359 of these forms of mercury can potentially cause any of 0:23:33.400 --> 0:23:36.280 these types of symptoms, right, because once it's in your body, 0:23:36.320 --> 0:23:38.920 it all acts relatively similarly. 0:23:39.280 --> 0:23:40.080 Right, that makes sense. 0:23:40.080 --> 0:23:44.080 There are still some subtle differences, but all right, so 0:23:45.359 --> 0:23:48.560 let's talk about our lungs first. You're most likely to 0:23:48.600 --> 0:23:51.440 be exposed to mercury in your lungs through mercury vapor, 0:23:51.560 --> 0:23:56.320 which is mostly elemental mercury. This happens most often in 0:23:56.320 --> 0:24:02.480 industrial or occupational settings, and inhalation of mercury vapor, especially 0:24:02.520 --> 0:24:07.080 a large amount, like more than a thousand micrograms per 0:24:07.240 --> 0:24:14.240 cubic meter of air, can cause massive interstitial numinitis. So 0:24:14.320 --> 0:24:19.720 this means inflammation in the lining surrounding, like the spaces 0:24:19.840 --> 0:24:23.280 in between your cells of your lungs. Because this mercury, 0:24:23.400 --> 0:24:25.520 you can kind of think of it as just ripping 0:24:25.600 --> 0:24:30.200 through the lining of your lungs. So you'll have all 0:24:30.240 --> 0:24:33.439 this inflammation, which will lead to a pretty severe cough 0:24:33.720 --> 0:24:36.680 because of all this fluid, a lot of chest pain 0:24:36.760 --> 0:24:39.480 because that fluid is going to irritate the whole lining 0:24:39.520 --> 0:24:44.480 of your chest, difficulty breathing. This mercury does distribute throughout 0:24:44.480 --> 0:24:46.800 your body, so it's common to have a rash that 0:24:46.880 --> 0:24:50.760 appears on the skin. People often have a metallic taste 0:24:50.760 --> 0:24:53.600 in their mouth and might feel nauseous or might vomit. 0:24:54.720 --> 0:24:57.000 They might start bleeding from the gums, which is a 0:24:57.000 --> 0:24:59.560 pretty common symptom of a lot of different forms of 0:24:59.600 --> 0:25:05.760 mercury poisoning is sort of ginge ofvitis, and then elemental 0:25:05.760 --> 0:25:09.120 mercury is removed from the body mostly through the kidneys, 0:25:09.160 --> 0:25:10.479 so we can see kidney failure. 0:25:10.720 --> 0:25:13.720 Okay, yeah, but often if. 0:25:13.720 --> 0:25:16.919 With large enough exposures, this is fatal. This is a 0:25:17.000 --> 0:25:20.560 very fatal form of exposure, and the death tends to 0:25:20.560 --> 0:25:23.359 be due to respiratory failure, especially in the case of 0:25:23.480 --> 0:25:27.159 children who are exposed to large quantities of elemental mercury vapor. 0:25:28.520 --> 0:25:31.760 What is a large quantity. 0:25:32.080 --> 0:25:37.440 So in general, these like acute symptoms would happen at 0:25:37.480 --> 0:25:42.160 pretty high concentrations, like above a thousand micrograms per cubic meter. 0:25:42.480 --> 0:25:44.640 I tried to get a sense of like how many 0:25:45.080 --> 0:25:48.080 grams of like liquid mercury would cause to get that, 0:25:48.320 --> 0:25:50.480 but I couldn't get that number. I think in part 0:25:50.520 --> 0:25:52.720 because it depends on like are you heating it or 0:25:52.800 --> 0:25:54.640 is it just at room temperature and all of that. 0:25:55.880 --> 0:25:59.879 But even at chronic, like lower levels of exposure between 0:26:00.240 --> 0:26:04.040 twenty five to one hundred micrograms per cubic meter of air, 0:26:04.480 --> 0:26:07.760 even those levels have been shown to be enough to 0:26:07.800 --> 0:26:13.159 cause chronic symptoms, which tend to be more neurologic. And 0:26:13.200 --> 0:26:15.400 we'll talk about the neurologic symptoms in just a bit. 0:26:16.359 --> 0:26:18.920 It's hard to picture those amounts, but I know. 0:26:18.840 --> 0:26:21.960 It's so that for a lot of this, even in fish, 0:26:22.000 --> 0:26:24.640 it's like I have no idea how much mercury that is. 0:26:26.119 --> 0:26:29.399