How do you get lead poisoning? Why lead keeps showing up where it’s not supposed to.

Lead keeps showing up where it’s not supposed to be.

In 2024, one of the most potent neurotoxins known to humanity persists all over the world as a public health threat. For the second time in six months, lead contamination in food products has put public health authorities on high alert in the wealthiest nation in the world. Last fall, contaminated cinnamon-applesauce pouches caused dozens of lead poisoning cases across the US, eventually prompting recalls in November. And in March, the federal government announced that some ground cinnamon products also contained slightly elevated levels of lead and advised customers not to buy them.

Lead might seem like something we left behind in a past era. By the 1990s, nearly every country had eliminated leaded gasoline, once easily the most ubiquitous source of lead pollution when we spewed it into the open air. The US and Europe also instituted more stringent rules for another common source of exposure, lead paint, by greatly restricting or outright banning its use. You can see the improvements in the numbers: From 1978 to 1991, the average level of lead in the blood for Americans younger than 75 dropped by 78 percent.

But lead usage has actually been on the rise worldwide, even in the US. The proliferation of lead-acid batteries globally and less stringent rules in the developing world for everything from cookware to spices has allowed lead consumption to grow despite its known health risks.

Lead is linked to a wide range of neurological and development problems, and exposure is especially dangerous for children. Research has found kids with elevated levels of lead in their blood experience a range of effects, from speech and hearing problems to learning and behavioral issues. They develop more slowly, physically and mentally.

And it remains an especially serious plight for poorer countries: A 2021 review of studies involving children in 34 low- and middle-income countries found that 48.5 percent had elevated levels of lead in their blood. But in a globalized economy, some of the same lead pollution endangering kids in those countries can find its way into consumer products that travel around the world and contaminate the food that children in the US eat.

In the case of the applesauce, the cinnamon was originally harvested in Sri Lanka and then shipped to Ecuador, where it was ground into powder to be mixed into the products. Both countries are dealing with lead exposure crises: One 2021 study found that almost all mothers and children living in Quito, Ecuador, had levels of lead and other metals in their blood that exceeded public health guidelines. The pollution stemming from Sri Lanka’s active lead-acid battery manufacturing and recycling sector, too, has created health problems for the workers and people who live near the plants.

When the applesauce ingredients passed through Ecuador, they were contaminated there with lead before they moved for sale to the US, where there have been more than 500 confirmed or suspected cases of acute lead poisoning related to the recalled products. The FDA believes the lead may have been added intentionally for economic reasons. The Ecuadorian government has named one individual as a suspect in its own investigation.

Matt Ramey/Washington Post via Getty Images

The entire episode encapsulates the difficult truth about lead: Even though the US has cracked down within its borders, pollution elsewhere persists — and, in some cases, American efforts to reduce its own pollution merely moved the contamination to other parts of the world.

“So much of the food that we eat is coming from all over the world,” said Stephen Luby, who studies lead pollution at Stanford University. “So we are deluding ourselves if we think we can push pollution problems to low-­income countries and not worry about it.”

It will take a multifaceted, multilateral, multinational strategy to eradicate lead contamination. And it starts with recognizing the whole world is in it together.

We keep finding lead everywhere we look

Lead exposure can be either high-grade (which can lead to acute poisoning and, in rare cases, even death) or low-grade (which can still result in developmental and cardiovascular problems).

The amount of lead in the cinnamon that was used in the applesauce pouches was enormous, with a concentration of more than 5,000 parts per million. That is thousands of times higher than the amount public health experts consider to be acceptable and high enough to cause acute lead poisoning.

The ground cinnamon the FDA warned about in March, by contrast, contained 2.03 to 3.4 parts per million. Although that amount is unlikely to result in an immediate ER visit, experts emphasize that no level of lead exposure is considered safe. Even these trace amounts could contribute to health problems over the long term when added to other exposures.

“We want to eliminate all exposures, don’t get me wrong, but I think that’s a very different situation with those much, much lower levels,” said Perry Gottesfeld, executive director of Occupational Knowledge International, an advocacy group focused on public health and industrial pollution.

One of the fundamental challenges in eradicating lead is that pollution can be low-grade and long-running. The lead that crept into our environment during the era of leaded gasoline and lead paint is still in the soil. Even pots and pans made from recycled aluminum that was mixed with leaded products or ceramics covered with a lead-based glaze (the kind used and traded around the world) can contribute over time to higher levels of lead in a person’s blood through degradation or exposure to heat.

“It’s always been there, to be honest. From a basic level, since industrialization, lead has been there,” said Jenna Forsyth, a research scientist at Stanford who works with Luby on lead research. “Lately, there’s been a closer inspection. And the more we look, the more lead we will find.”

A recent analysis from the environmental group Pure Earth examined more than 5,000 samples of consumer products in 25 low- and middle-income countries, ranging from foods and spices to cosmetics and toys to cookware and paints. It found that 18 percent of all samples had dangerous amounts of lead, based on reference levels drawn from public health agency guidelines. About half of all of the ceramic and metallic foodware and 41 percent of the residential and commercial paints tested had excess amounts of lead.

The US food supply relies on imports from countries with high levels of lead exposure, according to a 2019 report from the same group. The United States imports nearly all of its spices, coffee, and cocoa, for example. Independent tests conducted from 2014 to 2018 found most of the chocolate products tested — 96 out of 127 — had amounts of lead and cadmium (another dangerous neurotoxin) higher than the levels allowed in California, according to the Pure Earth report.

The US also imports about half of all fruits and vegetables consumed here. Farmers in lower-income countries must sometimes rely on untreated industrial wastewater to irrigate their crops, which can then contaminate the produce that is shipped around the world.

Once lead finds its way inside a person’s body, it quickly enters the bones because of its molecular similarities to calcium. It then subsists for decades, moving around and finding easy access to important organs, including the brain. And as lead takes up residence in places where calcium is supposed to be, it disrupts important biological and neurological functions.

“Lead is a toxin like no other,” Luby said. ‘People think about ‘Oh, yeah. Lead’s bad. Mercury’s bad. Cadmium’s bad. Air pollution is bad. All these things.’ No — lead is really disproportionately bad.”

Jaime Razuri/AFP via Getty Images

One global estimate of lead’s impact concluded that exposure had contributed to 5.5 million adult cardiovascular deaths and $6 trillion in lost economic potential in 2019. “But we don’t see lead. We don’t think about it,” Luby said. “When Dad dies of a heart attack, we don’t blame it on lead.”

Three reasons for continued lead contamination

We’re all at risk from lead — but not at equal risk. Children in low- and middle-income countries have average blood lead levels roughly three times higher than those in high-income countries, based on the available national data. While one in three children worldwide have dangerously high amounts of lead in their blood, the share is closer to one in every two children in the developing world.

Lead-battery manufacturing and recycling in lower-income countries where plants are subject to less regulation can lead to local pollution. There are fewer restrictions on lead in paint and other everyday products (food included) in the developing world. And, as mentioned, exposure also comes through agricultural practices. In the US, besides food imports, deterioration of aging civil infrastructure contributes to exposure, as was the case with lead-leaching water pipes in Flint, Michigan. Lead ammunition, commonplace in the US, has also been linked to elevated lead levels in children’s blood.

Lead’s persistence, unfortunately, is multifaceted. Drew McCartor, executive director of Pure Earth, put the sources into three buckets.

First, some polluters actively disregard the rules around lead use and its known health effects and intentionally continue to use lead in their products. Spices are a good example of how this can happen: Lead chromate pigment is often used to produce a more vibrant color in spices such as cinnamon and turmeric.

Forsyth, in her work with Luby to address lead exposure linked to turmeric among rural mothers in Bangladesh, noted that the use of lead chromate is “economically motivated.” It adds the yellow color desirable in traditional turmeric. It is also denser than the spice itself and reduces the amount of time it takes to process the turmeric’s roots, which increases the producer’s yield. The FDA has said it is investigating whether the presence of lead found in the cinnamon-flavored applesauce pouches was the result of such practices.

Companies have proven adept at migrating their operations to less restrictive jurisdictions. That’s a particular problem for lead acid batteries, which are most commonly used for automobiles and represent about 85 percent of lead’s use in the modern global economy. Most lead batteries are recycled to make new ones, but lead recycling has been linked again and again to the contamination of nearby soil and water.

The US sends most of its used car batteries to Mexico to be recycled, and the towns there that are home to recycling plants have been found to have extremely high lead levels. “You look at the history of battery recycling in the US, which is basically closed down and overwhelmingly moved to places where there’s weaker environmental regulation,” Forsyth said. “We in the wealthy world are like, ‘Oh, yeah, I want cheap batteries.’ And the fact that it’s killing people nearby in another country is a connection we don’t make.”

The second source of contamination is negligence, when companies fail to address lead levels that do not exceed regulations but still present a risk. A toy manufacturer that doesn’t test its raw materials for lead or a food maker who doesn’t perform due diligence on their suppliers may not be intentionally contributing to lead pollution, but their lackadaisical attitude allows lead to continue moving through the economy, where it ends up exposing consumers, including children.

Last, there are the legacy sources of lead, the result of our overdependence on the material in the decades before we realized how dangerous it was.

Lead was added to gasoline as an anti-knocking agent to improve the performance of automobiles’ combustion engines. By burning leaded gas, humans pumped lead into the atmosphere for decades; the US did not completely phase it out until 1996. That lead eventually settled into the soil, where it is difficult and expensive to remove.

It’s the same story with leaded paint: The paint chips and slowly erodes, creating lead-laden dust that finds its way into the soil or the water supply. Commonly used pesticides have likewise left lead behind in the ground where they were sprayed. And lead used in other products is likely to be around for years in one form or another, creating more and more of those small-scale exposures that add up over time.

Barbara Haddock Taylor/Baltimore Sun/Tribune News Service via Getty Images

“Lead is introduced into the material stream and then stays in that material stream as it’s reused for different purposes,” McCartor said. “These are usually small­-scale producers. So I wouldn’t describe them as irresponsible. They don’t have the means to test for lead. They are certainly not introducing it, I don’t think, intentionally. But it’s a product of our longstanding use of lead in the world.”

How do we get rid of all this lead?

The solution starts with the right policies — including prohibitions on the most potent sources of lead exposure — but it doesn’t end there.

The experts I spoke to said national governments could be more aggressive about cracking down on common sources of lead exposure. Lead paint, for example, is still widely used around the world. Even in the US, where its use is restricted for residential use, industrial use is fair game. More than 120 countries voted symbolically in 2009 to phase out lead paint, but there has been little action since.

Following through on that commitment would be one place to start. Environmental activists also advocate for prohibiting the lead chromates that are added to spices for appearance and weight, the suspected source of the recent lead scares in the US.

Given the outsize role of lead batteries in lead pollution, they are also necessary targets for change. But this presents an enormous economic challenge: These batteries are ubiquitous — used “in every electric vehicle, in every solar household, in every cellphone tower,” as Gottesfeld put it — and their alternatives have struggled to gain a market share. Lithium-ion batteries are the most common option, but they’re more expensive for manufacturers (and therefore, ultimately, the consumers) and present their own recycling challenges.

Still, experts say the world must keep working to reduce lead use and thereby exposure. Action by wealthy nations can create incubators for new alternative technologies as well as set an example for the rest of the world.

“When you look at the amount of human harm from all of this, it makes more sense for us to just move to substitutes and literally get this toxin out of the economy,” Forsyth told me. “I think that high­-income countries would be a great place to start. Because if they did this, they would both reduce their own risks and they would also clarify technologies and ways forward.”

But the right policies are insufficient. We also need more government attention and resources dedicated to the problem.

Removing lead from the soil has been chronically underfunded, even in the US, and the FDA’s negligence on the food side of its “food and drug” portfolio has been well documented. Monitoring of lead levels in food being imported to the US is minimal. That leaves America vulnerable to the weaknesses in other countries’ regulatory infrastructures, which are poorly funded and less robust.

In Mexico, although the pollution from lead battery recycling plants has raised the local lead levels above the country’s threshold for intervention, there has been little effort by the government to crack down on the industry. The tainted cinnamon that passed through Ecuador before ending up in applesauce pouches sold in US stores should have been subject to the country’s existing lead pollution laws, but oversight has stayed lax because of a lack of resources.

“Having the policy in place wasn’t enough. It wasn’t being enforced,” Forsyth said.

There are pockets of progress, as with Bangladesh and turmeric. McCartor said he’s been encouraged by a lead eradication campaign in Ghana, where his group collaborated with the national government to survey children for lead levels in their blood and to identify the likely sources of pollution.

The survey found that lead recycling plants were major contributors, much as they are in Mexico. So Ghana decided to shut down two of three lead recycling plants within its borders.

“We cannot inspect our way out of this problem. You could spend a fortune in perpetuity and only catch a tiny fraction of contaminated goods coming into the United States,” McCartor said. “If we really want to solve this, it requires a whole-­of-­government commitment to work outside of our borders.”