A lead poisoning mystery: How 2 detectives fingered a surprising culprit

“It’s the crime of the century,” says Bruce Lanphear.

He’s not talking about a murder spree, a kidnapping or a bank heist.

Lanphear – an environmental epidemiologist at Simon Fraser University – is referring to the fact that an estimated 800 million children around the world are poisoned by lead – lead in their family’s pots and pan, lead in their food, lead in the air. That’s just about half of all children in low- and middle-income countries, according to UNICEF and the nonprofit Pure Earth.

For decades, very little has been done about this. But this is the story of how two women – a New York City detective and a California student – followed the data and helped crack a puzzling case that spanned the globe in the ongoing “crime” of lead poisoning.

Meet New York’s lead lead detective

Next to a row of courthouses in downtown Manhattan, there’s an imposing gray building. On the 6th floor is an office that houses about 50 detectives. They work for New York City’s health department. They tackle thousands of cases a year involving kids exposed to toxic elements. And many of those cases are children who have too much lead in their blood.

The detectives’ job is to find the culprit. Could it be old chipping paint that’s creating lead dust that kids are breathing in? Could the lead be coming home on a parent’s clothes from, say, a factory or construction worksite and, then, the child breathes it in? Perhaps it was a toy from overseas, decorated with lead paint, that the kid repeatedly puts in their mouth?

The city detectives often search the child’s home armed with a device that resembles a radar gun – point it at, say, a wall, hold the trigger and you get a lead measurement of its paint.

Every time you go on such a mission, “it is absolutely a lead detective mystery,” says Paromita Hore, who oversees the detectives as director of environmental exposure assessment and education in the New York City Department of Health and Mental Hygiene.

When the mystery is solved — when they find the source of the lead — Hore’s team helps the family avoid additional exposure.

In the early 2000s, New York City's health department noticed a perplexing blip: A surprisingly large number of Bangladeshi children in New York City were showing up in their lead database.

“This is a problem,” Hore recalls thinking throughout the multi-year, multi-country effort to unearth the root cause.

Another mystery involving Bangladesh

As Hore’s team of lead detectives busily collected and analyzed samples from items found in the homes of New York’s Bangladeshi families, a student in California stumbled on a similar mystery.

Jenna Forsyth was a Ph.D. student in 2014 when her adviser gave her data on over 400 pregnant women in rural Bangladesh. He’d noticed that about half of the women had high levels of lead in their blood.

“I was kind of like, ‘Lead? I don't know. Is that really still that big of a problem?” she remembers thinking to herself. “‘We don't hear about it much anymore.’”

Then, she started reading the literature. And she quickly understood the severity of the Bangladesh lead levels. Lead can damage nearly every organ — from the kidneys to the heart — often irreversibly. In this case, both the woman and the fetus would be affected.

Perhaps lead’s biggest impact is on the brain. Exposure can lower a child’s IQ and spur cognitive decline in adults. It can cause long-term problems with impulsivity, attention and hyperactivity. When you look at the gap between what kids in upper-income and lower-income countries achieve academically, about 20% can be attributed to lead. Treatment can involve vitamin supplements or prescribing an agent that binds to the lead and helps remove it.

Lead exposure is also linked to cardiovascular disease, kidney damage and fertility problems, to name a few. It’s estimated that lead kills 1.5 million people each year in addition to those marked by disability and disease. Plus, a series of studies have linked increased lead exposure to societal ills, like higher crime rates and more violence — likely because lead has been linked to reduced brain volume and impaired brain function.

The World Bank took a stab at estimating how much this all costs – including the lost IQ points, the premature death and the welfare costs. They found the world's price tag for lead exposure is a whopping 6 trillion dollars annually – nearly 7% of the global gross domestic product.

“I was like, ‘Wow! Lead is just incredibly toxic,’” Forsyth recalls. “It’s one of the most toxic elements in the periodic table.”

And so, she dug into that data from Bangladesh.

“The prevalence of elevated blood lead levels in those women was about six times higher than those in Flint, Michigan, at the peak of the water crisis,” she says, remembering how Flint’s situation was considered horrific. “There was just this puzzle: Why would there be really high levels of lead poisoning in rural Bangladesh with no obvious source?”

Forsyth became so curious that she got on a plane and went to Bangladesh, where she teamed up with a renowned health research institute based there called icddr,b — formerly the International Center for Diarrheal Disease Research, Bangladesh. Together, they interviewed the pregnant women with high lead levels and came up with a number of possible causes:

Perhaps the lead came from agricultural pesticides? “We sampled hundreds of agrochemicals. Did not find lead in them,” Forsyth says.

Could it be lead in paint? “These women were living in primarily unpainted tin homes,” she says.

Perhaps it was lead-soldering on cans used to store food that can flake off into the food? It happens but it wasn’t common enough to explain the data.

Soil? Rice? No evidence found.

None of the investigative work led to a clue that would solve the puzzle. “So, we went back to square one,” Forsyth remembers.

She reviewed all the studies done on this population in case there was a hint that had been missed. Poring over scientific papers, she found one small study of 28 kids that looked at heavy metal exposure and found lead in turmeric, the bright yellow powder that’s used as a spice and is one of the most common ingredients in Bangladeshi cuisine.

Forsyth’s team started doing a bunch of testing and found there was indeed lead in both turmeric powder and turmeric roots they’d obtained in local markets. What’s more, the chemical fingerprint of the lead they found in the turmeric matched the lead in the women’s blood. Since there are four different types of lead, that was a eureka moment.

“It was like, ‘Okay! Yes! Now, we can focus [our attention],” Forsyth recalls. But there were lots more questions. One of their biggest: How could lead have gotten into the spice?

The older man and the secret

Forsyth and her colleagues set out to talk to turmeric farmers – including a man in his 70s. His ancestors were turmeric farmers and he’d been harvesting the root all his life. He knew the processing steps intimately – from the boiling and drying of the root to polishing off the outer layer and then eventually grinding, all to make a brilliantly yellow powdered spice.

“I remember we were sitting in the car – there was monsoon rain, splashing outside – and that's when the person said, ‘Yeah, back in the 1980s, there was a huge flood,’ ” Forsyth remembers.

With so much rain, the farmer told her, turmeric roots wouldn’t dry properly in the sun. Instead of turning their usual bright yellow, the roots became black-ish. The farmers were desperate to restore the color so they could sell their crop. They went in search of a solution.

“They found the cheapest yellow pigment available at that time,” Forsyth says.

The vibrant yellow pigment was lead chromate. It’s often used in industrial paints – think of the yellow of construction vehicles.

The farmers made a fateful decision: They started sprinkling lead chromate on the turmeric roots when it was being polished to make them look better. The lead chromate turned the roots a bright yellow. It worked so well it became common practice. The farmers kept using the lead chromate even after the flood waters receded since the lead-laced-roots were more appealing in the marketplace.

“They don't know that this is harmful for human health,” says Musa Baker, Forsyth’s colleague and a research investigator at icddr,b. “Rather, they want to expand their business” since their turmeric could now fetch a higher price.

This discovery that lead was routinely added to turmeric came as a shock, especially since the spice is part of daily fare for Bangladeshis, says Baker.

“It was really alarming,” says Dr. Mahbubur Rahman, the project coordinator at icddr,b.

Their team gathered all the data they could, published it and brought it to the authorities in 2019.

“The chairman of the Bangladesh Food Safety Authority, she took it very seriously,” says Baker.

What the chairman knew from their travels is that this issue wasn’t limited to Bangladesh. It had reached halfway across the world to New York as well.

The suitcase connection

That same year, in 2019, those New York City detectives had also figured out that spices – and particularly turmeric – played a major role in lead poisoning in New York’s Bangladeshi community and in other South Asian communities. In their investigations, they’d tested lots of consumer products used in Bangladeshi households and found that lead in spices emerged as the top culprit. Generally, these spices didn’t come from the U.S. Instead, most had been purchased overseas and brought to New York in unmarked containers tucked inside personal suitcases. Hore’s team alerted Bangladeshi authorities.

It turned out that Bangladesh was not the only source of lead-contaminated spices.

In 2017, the New York City Health Department helped uncover a major lead poisoning crisis in the country of Georgia that linked back to spices. Testing from New York’s Georgian population had set them on that “crime” trail. And their team, and other lead experts, have found worrisome spices in other South Asian countries. While Consumer Reports testing shows that spices in the U.S. can contain lead, Hore’s team found the highest concentrations of lead came from spices purchased abroad.

What sets Bangladesh apart is how quickly officials acted. In 2019, they met with Forsyth and her icddr,b colleagues. And they also flew to New York City to enter that imposing gray building and meet with the city’s health department.

Before the year was over, they’d put out public notices in the top newspapers warning the public and vendors not to buy the brightly colored root – instead buy the duller looking turmeric. (It’s hard to tell the difference in color with the powdered form.) They distributed 50,000 fliers with a similar message posting them in market places and elsewhere.

They also reached out to major turmeric farmers and held workshops with mill owners, explaining the dangers of adding lead both biologically and legally.

A gotcha moment

And then in October of 2019 came a scene that seems designed for a future Netflix series on “The Turmeric Mystery.” The Bangladeshi Food Safety Authority invited TV crews to bring their cameras to the main spice market in the capital city of Dhaka. A crowd of people watched as officials brandished one of those radar-gun-looking lead-measurement-devices. They pointed it at heaping sacks full of turmeric roots.

There was even a judge present to issue a ruling on the wholesale shop owners right there on the spot. The findings of this so-called “mobile court”: $9,288 were imposed in fines and nearly 2,000 pounds of turmeric were confiscated for their lead content.

And it worked.

Since then, Forsyth and icddr,b have regularly collected and tested dozens of samples of turmeric purchased from the main wholesale market in Dhaka. And, in the wake of this public campaign to expunge lead from turmeric, they’ve found that turmeric samples testing positive for lead dropped from 47% to 0%.

They also tested the blood of local turmeric farmers as well as pregnant women in the same Bangladeshi communities that had given those initial blood samples that set the whole investigation in motion. Here too, Forsyth says, they found a dramatic drop in blood lead levels.

“Honestly, we were so excited to see this,” she says.

Two cases solved, millions to go.

Today, Jenna Forsyth runs a global lead initiative at Stanford School of Medicine. She still teams up with icddr,b and, she says, they’re really busy.

“In Bangladesh, the case is closed on turmeric,” says Forsyth. “But when my friend was like, ‘You should take a break.’ I said, ‘No way. There’s more to be done.’ ”

Forsyth has found lead in spices in other countries, including parts of India and Pakistan. And in Dhaka, despite the lead-free turmeric, 98% of the kids she’s tested have lead poisoning by the U.S. CDC standard. “It’s wild,” she says.

“It's enough to destroy a nation,” says icddr,b’s Rahman.

She and icddr,b are in the process of teasing apart all the possible culprits that still lurk in Dhaka and in so much of the world: lead acid batteries that are improperly recycled; pots and pans made with scrap metal that contains lead; cookware glazes where it’s not fired to a high enough temperature and lead can leach into food; cosmetics – like the eye make-up surma and sindoor, the traditional powder used in Hindu practices – have been found to contain lead.

Paromita Hore’s team of lead detectives are hot on the case too. They’re gathering data about cosmetics, among other things. She meets with Forsyth – and other lead experts – monthly to compare notes and piece together the next mystery.

And recently they are celebrating some big news on the lead fighting front: This week, UNICEF and the United States Agency for International Development (USAID) announced a new $150 million initiative to combat lead poisoning.

“There's been so little done for so long, that this is really huge,” says Lanphear of Simon Fraser University.

The money – most of it from Open Philanthropy – will go to more than a dozen countries from Indonesia and Uganda to Ghana and Peru. And there will be a new public-private partnership aimed at boosting government buy-in, international coordination and jump starting an effort to get lead out of consumer products.

“It is long overdue that the world is coming together,” says Samatha Power, who runs USAID.

“There is a broad perception that it requires billions of dollars to transform a national or municipal infrastructure … to address lead poisoning. But in fact, there is an awful lot of low hanging fruit,” she says. “There is lead right now in paint, in spices, in cosmetics in developing countries. We think within just a few short years we can make sure that that lead has been eliminated and that kids are safe to play with their toys, to go to their schools.”

But Forsyth isn’t ready to retire. She keeps looking for lead in the usual (and unusual) places. She’s motivated, she says, because “it’s just really hard to tell a parent their kid has lead poisoning.” One day, she dreams that she’ll never again have to deliver such devastating news.