Lead poisoning kills millions annually. One country is showing the way forward.

My colleague Dylan Matthews recently wrote about the horrific global toll of lead poisoning, which contributes to as many as 5.5 million premature deaths a year — more than HIV, malaria, and car accidents combined.

Lead is a neurotoxin; it causes premature deaths and lifelong negative effects. It’s said “there is no safe level of lead exposure” — as far as we know, any lead causes damage, and it just gets worse the more exposure there is.

After a 20-year, worldwide campaign, in 2021 Algeria became the final country to end leaded gasoline in cars — something the US phased out in 1996. That should make a huge difference to environmental lead levels. But lots of sources remain, from car batteries to ceramics.

This isn’t a story about all the hard work still ahead of us, though: It’s a story about solutions, about one case where scientists, advocates, and policymakers came together to make one place in the world safer from lead.

Bangladesh phased out leaded gasoline in the 1990s. But high blood lead levels have remained. Why? When researchers Stephen Luby and Jenny Forsyth, doing work in rural Bangladesh, tried to isolate the source, it turned out to be a surprising one: lead-adulterated turmeric.

Turmeric, a spice in common use for cooking in South Asia and beyond, is yellow, and adding a pigment made of lead chromate makes for bright, vibrant colors — and better sales. Buyers of the adulterated turmeric were slowly being poisoned.

That bad news made a lot of headlines, especially as it became clear that adulterated spices were also poisoning kids in America (usually in cases where family had brought spices from abroad).

But there’s also good news: A recent paper studying lead in turmeric in Bangladesh found that researchers and the Bangladeshi government appear to have driven lead out of the turmeric business in Bangladesh.

Reporting from Bangladesh this summer, Wudan Yan in Undark narrates the gripping story of what happened after researchers realized that turmeric might be driving the shockingly high blood lead results they kept observing.

The researchers who’d isolated turmeric as the primary cause of high blood lead levels —working for the nonprofit International Center for Diarrheal Disease Research, Bangladesh — went to meet with government officials. They collected samples nationwide and published a 2019 follow-up paper on the extent of the problem. Bangladesh’s Food Safety Authority got involved.

They settled on a two-part approach, starting with an education campaign to warn people about the dangers of lead. Once people had been warned that lead adulteration was illegal, they followed up with raids to analyze turmeric and fine sellers who were selling adulterated products.

They posted tens of thousands of fliers informing people about the risks of lead. They got coverage in the news. And then they swept through the markets with X-ray fluorescence analyzers, which detect lead. They seized contaminated products and fined sellers.

According to the study released earlier this month, this worked spectacularly well. “The proportion of market turmeric samples containing detectable lead decreased from 47 percent pre-intervention in 2019 to 0 percent in 2021,” the study found. And the vanishing of lead from turmeric had an immediate and dramatic effect on blood lead levels in the affected populations, too: “Blood lead levels dropped a median of 30 percent.”

The researchers who helped make that result happen are gearing up for similar campaigns in other areas where spices are adulterated.

A lot of problems in the world are deep-seated and complicated, with many stakeholders and no clear way to make progress. Trying to solve climate change for example, as both activists and diplomats working now during Climate Week in New York City, won’t be a matter of finding a single bullet, but pursuing an arduous multi-decade, multi-stakeholder approach.

But sometimes, a problem exists because there was inadequate knowledge that it even was a problem, and insufficient will to enforce existing rules that would solve it.

One thing I find striking about Yan’s reporting from Bangladesh is that one supplier who sold adulterated turmeric had fed it to their own children. Others knew it wasn’t safe, but felt stuck selling it. They weren’t trying to do something monstrous; they either didn’t know about it, didn’t know what to do about it, or thought they’d go out of business if they stopped using the supplement while other businesses kept using it.

When the Food Safety Authority showed up at the market and started issuing fines for lead adulteration, it stopped being a savvy business move to add lead. Purchasers who were accustomed to unnatural lead-colored turmeric learned how to recognize non-adulterated turmeric. And so lead went from ubiquitous to nearly nonexistent in the space of just a few years.

That’s a better world for everyone, from turmeric wholesalers to vulnerable kids — all purchased at a shockingly low price. The paper published this month concludes, “with credible information, appropriate technology, and good enough governance, the adulteration of spices can be stopped.”

There’s still a lot more to be done. India, like Bangladesh, has widespread adulteration of turmeric. And safety testing will have to remain vigilant to prevent lead in Bangladesh from creeping back into the spice supply.

But for all those caveats, it’s rare to see such fast, decisive action on a major health problem — and impressive to see it immediately rewarded with such a dramatic improvement in blood lead levels and health outcomes. It’s a reminder that things can change, and can change very quickly, as long as people care, and as long as they act.

A version of this newsletter originally appeared in the Future Perfect newsletter. Sign up here!