By the way, the paper "How Much Would Reducing Lead Exposure Improve Children's Learning in the Developing World?", which seems relevant to this post, was evaluated by The Unjournal – see https://unjournal.pubpub.org/pub/evalsumleadexposure/. Please let us know if you found our evaluation useful and how we can do better; we’re working to measure and boost our impact. You can email us at [email protected], and we can schedule a chat. (Semi-automated comment)
We just published an interview: Lucia Coulter on preventing lead poisoning for $1.66 per child. Listen on Spotify or click through for other audio options, the transcript, and related links. Below are the episode summary and some key excerpts.
I always wonder if one part of it is just the really invisible nature of lead as a poison. Of course impacts aren’t invisible: millions of deaths and trillions of dollars in lost income. But the fact that lead is the cause is not apparent. It’s not apparent when you’re being exposed to the lead. The paint just looks like any other paint; the cookware looks like any other cookware.
And also, if you are suffering the effects of lead poisoning, if you have cognitive impairment and heart disease, you’re not going to think, “Oh, it was that lead exposure.” It’s just not going to be clear.
- Lucia Coulter
Lead is one of the most poisonous things going. A single sugar sachet of lead, spread over a park the size of an American football field, is enough to give a child that regularly plays there lead poisoning. For life they’ll be condemned to a ~3-point-lower IQ; a 50% higher risk of heart attacks; and elevated risk of kidney disease, anaemia, and ADHD, among other effects.
We’ve known lead is a health nightmare for at least 50 years, and that got lead out of car fuel everywhere. So is the situation under control? Not even close.
Around half the kids in poor and middle-income countries have blood lead levels above 5 micrograms per decilitre; the US declared a national emergency when just 5% of the children in Flint, Michigan exceeded that level. The collective damage this is doing to children’s intellectual potential, health, and life expectancy is vast — the health damage involved is around that caused by malaria, tuberculosis, and HIV combined.
This week’s guest, Lucia Coulter — cofounder of the incredibly successful Lead Exposure Elimination Project (LEEP) — speaks about how LEEP has been reducing childhood lead exposure in poor countries by getting bans on lead in paint enforced.
Various estimates suggest the work is absurdly cost effective. LEEP is in expectation preventing kids from getting lead poisoning for under $2 per child (explore the analysis here). Or, looking at it differently, LEEP is saving a year of healthy life for $14, and in the long run is increasing people’s lifetime income anywhere from $300–1,200 for each $1 it spends, by preventing intellectual stunting.
Which raises the question: why hasn’t this happened already? How is lead still in paint in most poor countries, even when that’s oftentimes already illegal? And how is LEEP able to get bans on leaded paint enforced in a country while spending barely tens of thousands of dollars? When leaded paint is gone, what should they target next?
With host Robert Wiblin, Lucia answers all those questions and more:
Producer and editor: Keiran Harris
Audio Engineering Lead: Ben Cordell
Technical editing: Milo McGuire and Dominic Armstrong
Transcriptions: Katy Moore
Lucia Coulter: So lead is extremely toxic. One way to think about why is that basically, it mimics calcium and other metal ions that serve these essential functions in pretty much every part of the body. And we’ve evolved for the vast majority of our history in an environment where lead was buried in the earth, so our cells are just not well adapted to tolerate any of this interference. And it interrupts many different subcellular processes, and that affects pretty much every organ system.
So we could think about it in terms of what would the impact be on the average child in a low- or middle-income country? The average child in a low- or middle-income country has a blood lead level of around 5 micrograms per decilitre, and that’s high enough to cause health, educational, and economic impacts. So a child with that blood lead level would have a reduction in IQ anywhere from around one to six IQ points, depending on which analysis you take. That, in turn, will affect their future earning potential. They’ll also have reduced educational attainment. There was a recent analysis by the Center for Global Development that pretty conservatively concluded that would be equivalent to around one year of lost schooling.
And then it also causes an increased likelihood of cardiovascular disease and mortality from cardiovascular disease. And that could be as high as a relative risk of around 1.5 at the average level of lead exposure that children have in low- and middle-income countries. That’s according to a recent analysis of US data.
And then on top of all of that, it increases risk of kidney disease, anaemia, foetal health problems, behavioural disorders, ADHD, and possibly even mental health problems and dementia.
Rob Wiblin: So one thing is, because we evolved for so long in an environment where lead was not present, we don’t have any bodily process for removing lead. So it tends to just hang around in the body for a very long time, and it ends up in all kinds of different tissues. I think in adults, often it can end up in the bones, and it tends to hang around there a long time and then gradually leach out, over decades even. But it’s not something that you just consume and then pee out very quickly. It hangs around for a long time.
And as you’re saying, it mimics other metal ions that we do need to use, so it interferes with all kinds of different enzymes throughout the body that are doing just the basic work of a cell. It’s getting in there and just screwing them up constantly. It’s also mimicking calcium ions in the brain, so it gets into the brain and then it screws up the ability to send signals between neurons.
Lucia Coulter: And that’s particularly dangerous when children are very young and their brains are developing, because that’s such a complex and delicate process — which is why it has such a severe impact on young children, by impacting the way that their brains are forming and all those neurons are connecting in the very early years.
Rob Wiblin: If I understand correctly, 40 years ago about 90% of people’s exposure to lead, in rich countries at least, was coming via leaded petrol, which has now been almost completely eliminated everywhere. Well, I guess except for avgas. This is one crazy thing that I learned: that we haven’t figured out a way to run planes safely without putting lead in the petrol there, which is one of the top reasons now that people still get exposed to lead in countries like the UK or the US. But anyway, as a result of getting rid of leaded gasoline, we’ve seen a massive decrease in lead levels in children in the US — by around 90% since the late ’70s, and probably something in that ballpark for the UK and Australia, although I think that the data on that is surprisingly rickety; it was a little bit hard to find any good systematic studies of that in recent years.
But an interesting thing is that the research suggests that most damage is done by the first bits of lead that you get exposed to: it’s actually the first milligram that’s doing the most damage per milligram, and then you get gradually declining damage, which is counterintuitive. I suppose the mechanism might be that, as you get exposed to more and more lead, all the damage that can be done by lead specifically has already been done; it kind of runs out of low-hanging fruit to harm you even more.
Anyway, if that’s the case, the damage that lead is doing to people’s health — even in rich countries, where the exposure levels have been reduced 90% — could still be really quite meaningful. It’s not necessarily enough to reduce it 90% — you really want to reduce it by more like 99% or 99.9% in order to feel comfortable that we’ve done enough.
One thing I’ll just note is that listeners might recall all of the news coverage of Flint, Michigan a couple of years ago where they screwed up something about their water supply and children were getting exposed to lead above the US’s permitted limits. But the blood lead levels that led to the declaration of a national emergency in the US are just completely standard in India: I think 5% of the children in that city had blood lead levels above 5, but I think two-thirds of children in India have that level of lead in their blood, and that’s just regarded as completely normal and a matter of course. It’s kind of crazy.
Anyway, that is a huge lead-in to this question: How many times more damage is lead doing in countries that LEEP operates in, as opposed to countries like the US or UK, where most listeners live?
Lucia Coulter: Yeah, it’s really crazy, that statistic. So LEEP operates in low- and middle-income countries, and 95% of the global burden of lead poisoning roughly is concentrated in low- and middle-income countries. In low- and middle-income countries, the average blood lead level is around 5 micrograms per decilitre, which is classified as lead poisoning — so on average, most children have lead poisoning. And in high-income countries, the average childhood blood lead level is around 1 microgram per decilitre. It’s a bit lower than that in the US. And like you say, the data is not amazing anywhere on this, but it’s about five times lower in high-income countries.
And the Flint, Michigan example is really stark. I think that was a huge crisis, having 5% of children in Flint, Michigan with lead poisoning. But the fact that just every single day, 50% of children in low- and middle-income countries have that level of lead poisoning is really concerning, really troubling.
Rob Wiblin: We’ve known for at least 100 years that lead is poisonous. I guess we can see that because France banned leaded paint in 1909. I think they were one of the first countries to do it. But nonetheless, they thought it was sufficiently dodgy that there was lead going in paint in houses that they banned it 110 years ago. And apparently even the ancient Romans suspected that lead was bad for you. I guess they probably didn’t have gold standard randomised controlled trials, but they probably noticed that people who worked in lead mines ended up with extreme health problems, and figured out that lead was probably bad for you.
Is there a simple reason why this problem hasn’t already been solved? Why didn’t we know in the 19th century to stop adding lead to stuff that people were going to be eating?
Lucia Coulter: I think it’s a good question. It’s probably not that simple of an answer. I think to start with, lead is just a really useful metal: it’s abundant, it’s malleable, it’s durable, and its compounds make loads of really helpful things — like strong glazes, bright pigments, antiknocking fuels. I think in the ’20s the industry in the US described lead as “a gift from God” because it’s just such a great thing. So I think people will just keep using it unless they aren’t able to, unless they’re strongly incentivised not to.
I think another reason is that there is extremely low awareness of both the prevalence of lead poisoning and the harms of lead poisoning, and the sources of exposure. Low awareness generally, but also among important decision-makers, important institutions, and low- and middle-income country governments and funders. I guess that leads to the question: Why is the awareness so low?
Rob Wiblin: Yeah, maybe this is something that a historian should be looking into understanding. Maybe they could find some mentions in parliamentary records or something from the 19th century of people raising the question of whether lead was safe. There must have been some stuff written about it, if it was banned in France in 1909. But why is it that that didn’t win the day? Why is it that industry, that wanted to add lead to things, won out the debate?
Lucia Coulter: Yeah, I always wonder if one part of it is just the really invisible nature of lead as a poison. Of course impacts aren’t invisible: millions of deaths and trillions of dollars in lost income. But the fact that lead is the cause is not apparent. It’s not apparent when you’re being exposed to the lead. The paint just looks like any other paint; the cookware looks like any other cookware. And also, if you are suffering the effects of lead poisoning, if you have cognitive impairment and heart disease, you’re not going to think, “Oh, it was that lead exposure.” It’s just not going to be clear.
Rob Wiblin: I guess it’s an issue with how we tend to treat specific acute diseases and be very aware of that, but then everyone suffering some relatively small chronic impact just doesn’t really rise to the level of anyone’s notice and cause a public outcry.
Lucia Coulter: Yes, exactly. And the symptoms aren’t specifically characteristic of the cause. It’s not like malaria, where you get cyclical fevers and it’s like, obviously something going on here. I think that’s part of it as well.
Lucia Coulter: We were helping the Malawi Bureau of Standards — supporting them with testing capacity, updating their regulation to make it more enforceable, and making sure that the right samples were being collected. It needs to be coloured paints, because they’re much more likely to be leaded than white paints. And the default globally for anyone doing monitoring of a paint industry would be to just collect white paints, so you’d naturally miss lead in that. So that’s a bit of a process. And then industry typically is unlikely to reformulate until they feel that there will be consequences.
Rob Wiblin: Did you call them up and say… ?
Lucia Coulter: We spoke to them before we did the study, and we said, “You’re aware of lead as an issue in paint?” and that sort of thing. Broadly, they said that they were aware of it, but that maybe some other manufacturers were doing it, but not them. So then we come back with the results and we say, “There is a lot of lead in your paint.” And they’re like, “Ah, OK” — and at that point we offer our support.
So we can help in quite a few ways. We have a paint technologist who’s absolutely amazing, who can give really detailed technical support with the switch. We can help them find suppliers of the non-lead raw materials, which can sometimes be a barrier because their usual suppliers might not necessarily supply these non-lead alternatives. We also offer to retest their paints for them so they can be confident that they’re lead-free and that sort of thing.
Some of them engaged, some of them didn’t really. Some of them said to us, like, “I don’t really know. Does the Malawi Bureau of Standards really have testing capacity? Do we really have to do this?” And so we were like —
Rob Wiblin: Wow, that’s ballsy to be saying, “OK, sure, you busted us, but we don’t think that you have the testing capacity to check again, officially.”
Lucia Coulter: Yeah, exactly.
Rob Wiblin: Interesting. Were any of them mortified? Sounds like no.
Lucia Coulter: No, not that was apparent to me. I mean, I don’t know how they were feeling internally. In a professional context, you might not really let on your real feelings about it. I think that from the perspective of a manufacturer, they’re only putting in a small amount of lead: 1% intuitively doesn’t feel like that much, right?
Rob Wiblin: It’s just a splash of lead. Just a little bit.
Lucia Coulter: Just a tad. So I think it’s not intuitive, how bad that could be. One way of communicating it is that if you had a little sugar sachet — the type that you would get at a cafe to put in your coffee — if that was filled with lead dust, and you sprinkled it across an area the size of an American football field, that level of lead loading would be sufficient to cause lead poisoning if a child spent time in that environment. So a very, very small amount of lead can have these really toxic effects. And that’s not intuitive; that’s pretty surprising.
So I think that’s probably how people think about it. But often manufacturers, in some of our experience, will move really quickly. Sometimes days after we show them the results, they’ve ordered their non-lead alternative ingredients.
Lucia Coulter: There are many different sources of lead exposure in low- and middle-income countries. Paint we’ve talked about. Others include aluminium cookware, lead-glazed ceramics, cosmetics, lead-adulterated spices, water systems, lead-acid battery recycling, mining, and recycling. There are probably others too that we don’t even really know about yet. And we don’t really know which exposures are most significant in which countries, or the relative contribution of different sources in different areas: there’s a big lack of data. It does look like it varies a lot geographically, but there’s enough to make some educated guesses.
As to why we’re focused on paint, it’s because it seems like a widespread, important source of exposure that’s also unusually tractable and also very neglected. I think the tractability is probably a really important factor, and possibly more differentiating than those others. We know that with a little bit of support, low- and middle-income country governments can get lead paint off the market, which is a big reason why it’s so cost effective to work on.
Rob Wiblin: Let’s just pause again on what those other sources are. So there’s lead-acid batteries from cars: there’s people who are doing informal recycling of those, I assume in pretty poor areas. And of course, if you’re involved in that, that’s a massive exposure of lead for you.
Lucia Coulter: Yeah, or if you live nearby.
Rob Wiblin: I guess it ends up in the soil if you live nearby. So that’s going to be concentrated in particular locations, but then very severe in those spots.
Lucia Coulter: Exactly.
Rob Wiblin: Then, I did not know this until recently, but there’s lead put sometimes in crockery that people are eating off of. And you’re saying there’s lead glazes, so sometimes you put colourful decorations onto bowls that people are eating out of, and that can have very high concentrations of lead in it.
Lucia Coulter: Yeah. So the kind of paint put on bowls or whatever, that can have very high concentrations of lead. But also just the normal glaze that’s used to seal a piece of pottery, like just the normal ceramic, that often has very high levels of lead. It can be sealed and fired at high temperatures and done in a way that means that the lead doesn’t leach into the foods very much, but in many low- and middle-income countries, it’s done in a way where it does leach into the food a lot. In South America and Latin America that’s been a big problem, probably also in a number of other regions as well.
Rob Wiblin: But people haven’t even identified that it’s an issue yet.
Rob Wiblin: A different angle on how to get a really big systemic change here: How much does it cost to test for lead in someone’s blood? We said it was $27 or so for a sample of paint. How much for a person’s blood sample?
Lucia Coulter: It’s probably similar. Probably you could get it at around that price.
Rob Wiblin: How much of a game changer would it be to have a way of easily and really cheaply measuring lead in blood or in objects or in paint? What if you could do it for a dollar or less?
Lucia Coulter: That would be huge. That would be a game changer. If you could measure the lead content of objects — like paint or other sources of exposure — cheaply, accurately, and also in a really low-tech, simple, easy way, that would be huge for the government testing capacity problem. You could imagine, like this lead gun that we have here, if a government regulatory authority could have one of those and it was going to be accurate and it wasn’t going to break, that they could just go around testing loads of things and enforce on the basis of it. So I think that would be a real game changer.
There is work to try and get these portable XRF devices, to try and figure out with what method can the result be accurate enough that it could be used for enforcement by a low- or middle-income country government. We were talking just over the last few weeks with Stanford University and Mercer University, where they’ve been working on methods to get accurate results so that you can use XRF for paint testing. And they’re hoping to get a project funded so that that can be an approved method by these international standards bodies. And then if it were an approved method, then governments could actually do that, and that would be pretty big, I think.
Rob Wiblin: Got it. So there are some ways of doing this that there’s ways that we could try to make it a bunch cheaper. Our current issue is that these things are kind of roughly accurate, but they’re not nearly as precisely accurate. So governments are wary of imposing penalties on businesses or telling them they can’t sell something based on the x-ray gun because it’s not quite as precise as sending it off to a lab for measurement.
Lucia Coulter: Yeah. And also the x-ray guns are expensive. They can cost like $20,000 or $30,000. But they’re less expensive than the lab-based methods.
Rob Wiblin: If you test enough things, yeah.
Lucia Coulter: And you wouldn’t need many of them. I mean, they’re less expensive than the lab-based methods if you have to have your own testing equipment. If you can use an international lab, then that would be pretty low cost.
Rob Wiblin: Here’s a completely different angle: I suppose this is not actually a more systematic intervention; this is almost the opposite of that. But I think doctors sometimes do what are called “very brief opportunistic interventions,” where they just ask someone when they happen to be in with another health issue, they happen to be in the GP office, are they interested in quitting smoking? And then if they say yes, then they help them out and instruct them on how to do that.
Now, this doesn’t prompt that many people to quit, as you might imagine. It’s a very light-touch intervention. But it can be really cost effective in terms of quits per hour of physician time, because it takes almost no effort per person to do this. So it’s recommended that physicians give this a go basically every time they get the chance.
Maybe the same principle could work here. Could you just call up every paint factory, basically, in sub-Saharan Africa and say, “Do you know whether you use lead? Do you realise that this is extremely bad for children’s health? Have you considered quitting lead? Have you considered putting something else in your paint?” And then maybe 1% of them or 10% of them, that might be all that’s needed in order to prompt them to take action. What do you reckon?
Lucia Coulter: I love it. I don’t think that’s a crazy idea. The other thing you could do is raw material suppliers. Suppliers of non-lead alternatives provide free samples. So you could also say, “And would you like to receive a free sample?” And then just send it to them.
I think usually it is harder to engage with manufacturers when you haven’t done a paint study and you don’t have the results. And usually they won’t act until regulation is on the horizon. But that’s not always the case, and I think you’d get some hits. So, over the past few months, we have started trying to engage manufacturers a lot earlier. And it does seem promising, but I think if anyone’s got some free hours and just wants to start cold calling…
Rob Wiblin: “Our paint technicians are standing by to reformulate your paint.” To be honest, I don’t know if this is actually a good idea, because it seems like with a reasonable amount of money, you’re on track to target all of the paint factories in large countries, at least in sub-Saharan Africa, for example, by doing these paint studies and getting the government to take action. So maybe if you had one person who had only $10,000, maybe this would be the best that they could do. But given that you have more people and more expertise and you are trying to scale, this probably seems less cost effective to me.
Lucia Coulter: Yeah, maybe for us, but if someone’s got free time…
By the way, the paper "How Much Would Reducing Lead Exposure Improve Children's Learning in the Developing World?", which seems relevant to this post, was evaluated by The Unjournal – see https://unjournal.pubpub.org/pub/evalsumleadexposure/. Please let us know if you found our evaluation useful and how we can do better; we’re working to measure and boost our impact. You can email us at [email protected], and we can schedule a chat. (Semi-automated comment)
Correction: Apologies — the DOI link in the comment above is broken. The correct link to The Unjournal's evaluation summary of "How Much Would Reducing Lead Exposure Improve Children's Learning in the Developing World?" is: https://unjournal.pubpub.org/pub/evalsumleadexposure/