Elise Hu wastes no time setting the stakes: lead poisoning, a problem most Americans have filed away as history, is still actively destroying children's minds and bodies worldwide. She introduces Drew McCartor as the head of Pure Earth, a 2025 TED Audacious Project grantee working to prevent exposure to toxic pollutants globally. With a teaser of the key numbers — 2 million IQ points permanently lost in children every day, and more deaths than all wars, natural disasters, road accidents, HIV, and malaria combined — she primes listeners for a talk that is equal parts alarming and optimistic. The framing is deliberate: this is not a hopeless story, because Pure Earth has a proven model already working in more than 20 countries. Hu also promises a post-talk conversation with Audacious Project's Hasiba Haqq on why this work resonates even in places that think they've moved past lead as an issue.

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Standing on the TED stage at TED2026, Drew McCartor delivers his opening with visual punch: behind him, a screen counts upward in real time, tracking IQ points being permanently stolen from children by lead poisoning. Because this is an audio format, host Elise Hu steps in to paint the picture — a black background, large white numbers already well below 100 and climbing fast, captioned 'Real-time IQ loss.' McCartor explains that by the end of the day, the number will exceed 2 million, then reset and do it again tomorrow, and every day after, until the world acts. It's a device that transforms an abstract global statistic into something viscerally immediate — a clock counting down not time, but human potential. The moment sets the register for the entire talk: urgent, specific, and grounded in data rather than sentiment.

The numbers McCartor presents are so large they risk sliding past the audience without landing — so he names every comparator explicitly. In 2023, lead claimed more lives than all active wars combined, all natural disasters, all road accidents, HIV, and malaria — not any one of those, but all of them added together ^{[1] — Drew McCartor "In 2023, lead poisoning killed more people than all active wars, natural disasters, road accidents, HIV, and malaria combined. Most people …" 09:00 Play} . Beyond its impact on cognition, he explains, lead is a cardiovascular killer: it drives heart attacks and strokes at a scale that most of the world has no framework to comprehend. The cause of death is rarely logged as 'lead poisoning' on a death certificate, which helps explain why the crisis stays invisible. McCartor's delivery is measured and deliberate — he is not trying to shock for shock's sake, but to dismantle the comfortable assumption that lead is an old problem, already handled, already solved. It hasn't been.

Pure Earth first met Saim when they were cleaning up lead contamination in a Bangladeshi village, caused by men who had leased a plot of land to extract lead from old car batteries, melting the plates over open fires and spreading toxic dust across the community. Saim's mother knew something was wrong long before any test: her son, once attentive and progressing well in school, had begun forgetting everything. McCartor shows a video of Saim in conversation with his teacher, translated from Bengali by Elise Hu for audio listeners. In the exchange, Saim tells his teacher he's in Grade 2, then Grade 3, then says he cannot remember — shaking his head at the end of the clip ^{[1] — Drew McCartor "Saim grew up near men recycling lead from car batteries in open fires in Bangladesh. Before the lead arrived, he was doing well in school. …" 09:40 Play} . McCartor makes the detail personal: he has a daughter Saim's age, and every parent knows that a child's grade level is a cornerstone of their identity. No third grader tolerates being called a second grader. To forget it entirely is not a quirk — it is evidence of catastrophic, irreversible neurological damage. Saim's story becomes the emotional anchor for everything that follows.

To explain why Saim's memory cannot be restored, McCartor walks the audience through what lead actually does inside a child's brain ^{[1] — Drew McCartor "Lead mimics calcium in the developing brain, tricking it into using lead instead of calcium to build neural connections. The result is a ch…" 12:40 Play} . He asks us to picture the developing brain as a new city under construction — and calcium as the expert city planner, directing neural crews to build synaptic roads and bridges that enable learning, memory, and impulse control. Lead, he explains, is a chemical impostor: it mimics calcium so convincingly that the brain uses it in place of the real thing. But lead is a terrible planner. It directs those same neural crews to build dead-end streets and bridges to nowhere — a chaotic, non-functional network that, once formed, cannot be torn down and rebuilt. The damage is permanent by design, because the brain does not re-lay its foundations. This mechanism, McCartor reveals, is not a rare misfortune: more than 1 billion children and teenagers worldwide currently have blood-lead levels above the WHO intervention threshold ^{[2] — Drew McCartor "More than 1 billion children and teenagers worldwide have blood-lead concentrations above the WHO intervention threshold. That's 1 in every…" 13:40 Play} . That is 1 in 3 children on Earth. He pauses and lets the number sit: 'A billion. That's one in three. Now imagine you're looking at your kids, and you have to choose. Which one?'

The individual story of Saim is devastating. But McCartor wants the audience to grasp what 1 billion versions of Saim means for humanity ^{[1] — Drew McCartor "At current average exposure levels, lead is sufficient to shift the global intelligence curve downward — cutting in half the number of chil…" 14:30 Play} . In low- and middle-income countries, he explains, the average child's lead exposure is high enough to subtract 4 to 5 IQ points from their development — a number that, applied across entire populations, is enough to shift the intelligence curve downward for the whole generation. The downstream effects are not abstract: the number of children with IQs above 130 — the gifted tier — is cut in half. And the number of children with IQs below 70, the threshold for intellectual disability, increases by 50%. These are not edge cases or statistical curiosities. These are the scientists, artists, engineers, and leaders the world will never have — and the number of people who will require lifelong support who didn't need to. McCartor closes the section with his most memorable line: 'If you rob one child of their potential, that's a tragedy. But to do it to a billion kids, that changes the trajectory of humanity.' Then, a pivot: 'OK, that's all the bad news. Now the good news: this thing is solvable.'

Having established the scale of the crisis, McCartor pivots to the solution — and he's unusually specific. Pure Earth has spent 25 years field-testing lead-prevention strategies across diverse environments, and the learnings have crystallised into a three-step model designed for government adoption. Step one: conduct a nationally representative survey of children's blood-lead levels, typically requiring a few thousand tests. The goal isn't just measurement — it's motivation. Governments that see their own data almost always respond, because the numbers are nearly always alarming. Step two: identify local exposure sources. McCartor pushes back gently on the Western assumption that old paint and pipes are the main culprits everywhere. In other countries, the lead comes from food and spices, traditional cosmetics and medicines, ceramic glazes, cheap aluminum cookware, and industrial pollution — the sources are wildly variable and must be identified on their own terms. Step three: regulate and remove. This means tightening standards, building enforcement capacity, and cleaning up old contaminated sites ^{[1] — Drew McCartor "Survey children's blood-lead levels to establish a national baseline. Identify the local exposure sources — which vary wildly from spices t…" 16:30 Play} . McCartor is careful not to oversell the simplicity: 'I don't want to pretend like it's easy. It's not easy, but it's also not rocket science.' His confidence comes from evidence — the model works when governments commit to it.

Georgia is McCartor's flagship proof of concept, and it's an unlikely one ^{[1] — Drew McCartor "In 2018, 41% of Georgian children exceeded the WHO lead threshold. The source: lead-based pigments added to spices for vivid color. After P…" 18:00 Play} . In 2018, a nationally representative survey conducted with UNICEF found that 41% of Georgian children had blood-lead levels exceeding the WHO intervention threshold — a number that shocked the government and created political will for action. Pure Earth was brought in to identify the exposure source, and the culprit turned out to be hidden in plain sight: spices. Vendors were adding lead-based pigments to products like paprika and turmeric to make them more vivid — those brilliant oranges and reds that signal freshness and quality to buyers. The government tightened its regulations, improved enforcement capacity, and the results were swift and dramatic. In the hardest-hit regions, lead levels dropped by 75% ^{[2] — Drew McCartor "Georgia lead levels down 75%: After Pure Earth helped Georgia identify lead-contaminated spices and tighten regulations, lead levels in the…" 18:38 Play} . McCartor notes that the Georgian government now owns the agenda — the international organisations have stepped back, and the country is protecting its next generation on its own terms. He uses Georgia to show that the model isn't theoretical. Then he names other countries at various stages: the Philippines got their first large-scale survey. Ghana identified its sources. Mexico reduced lead-based ceramic glazes. The pipeline of progress is real.

Georgia is McCartor's flagship proof of concept, and it's an unlikely one ^{[1] — Drew McCartor "In 2018, 41% of Georgian children exceeded the WHO lead threshold. The source: lead-based pigments added to spices for vivid color. After P…" 18:00 Play} . In 2018, a nationally representative survey conducted with UNICEF found that 41% of Georgian children had blood-lead levels exceeding the WHO intervention threshold — a number that shocked the government and created political will for action. Pure Earth was brought in to identify the exposure source, and the culprit turned out to be hidden in plain sight: spices. Vendors were adding lead-based pigments to products like paprika and turmeric to make them more vivid — those brilliant oranges and reds that signal freshness and quality to buyers. The government tightened its regulations, improved enforcement capacity, and the results were swift and dramatic. In the hardest-hit regions, lead levels dropped by 75% ^{[2] — Drew McCartor "Georgia lead levels down 75%: After Pure Earth helped Georgia identify lead-contaminated spices and tighten regulations, lead levels in the…" 18:38 Play} . McCartor notes that the Georgian government now owns the agenda — the international organisations have stepped back, and the country is protecting its next generation on its own terms. He uses Georgia to show that the model isn't theoretical. Then he names other countries at various stages: the Philippines got their first large-scale survey. Ghana identified its sources. Mexico reduced lead-based ceramic glazes. The pipeline of progress is real.

Georgia is McCartor's flagship proof of concept, and it's an unlikely one ^{[1] — Drew McCartor "In 2018, 41% of Georgian children exceeded the WHO lead threshold. The source: lead-based pigments added to spices for vivid color. After P…" 18:00 Play} . In 2018, a nationally representative survey conducted with UNICEF found that 41% of Georgian children had blood-lead levels exceeding the WHO intervention threshold — a number that shocked the government and created political will for action. Pure Earth was brought in to identify the exposure source, and the culprit turned out to be hidden in plain sight: spices. Vendors were adding lead-based pigments to products like paprika and turmeric to make them more vivid — those brilliant oranges and reds that signal freshness and quality to buyers. The government tightened its regulations, improved enforcement capacity, and the results were swift and dramatic. In the hardest-hit regions, lead levels dropped by 75% ^{[2] — Drew McCartor "Georgia lead levels down 75%: After Pure Earth helped Georgia identify lead-contaminated spices and tighten regulations, lead levels in the…" 18:38 Play} . McCartor notes that the Georgian government now owns the agenda — the international organisations have stepped back, and the country is protecting its next generation on its own terms. He uses Georgia to show that the model isn't theoretical. Then he names other countries at various stages: the Philippines got their first large-scale survey. Ghana identified its sources. Mexico reduced lead-based ceramic glazes. The pipeline of progress is real.

The endgame McCartor describes is ambitious by any measure: Pure Earth rolling out its tested, government-facing three-step model in more than 20 countries simultaneously, covering a combined population of 500 million children ^{[1] — Drew McCartor "Backed by the Audacious Project, Pure Earth is deploying its three-step model in over 20 countries home to 500 million children. Over the n…" 19:45 Play} . The funding vehicle is the Audacious Project, TED's initiative to back transformative global ideas at scale. McCartor is careful to frame the timeline in generational terms — over the next eight years, he expects the program to measurably improve the intellectual capacity, physical health, and longevity of those half a billion children. But the benefits don't stop there: every generation raised in those environments after the lead is gone inherits a cleaner, safer developmental landscape. He closes on Saim — acknowledging that nothing can give back what lead stole from him — and pivots to the millions of young brains still under construction that can still be reached. 'We have to get to them before lead does.' It's an invitation, not a lament: the model exists, the funding exists, and the only remaining bottleneck is awareness.