Smartphones, computers and electric vehicles may be emblems of the modern world, but, says Siddharth Kara, their rechargeable batteries are frequently powered by cobalt mined by workers laboring in slave-like conditions in the Democratic Republic of Congo.

Kara, a fellow at Harvard's T.H. Chan School of Public Health and at the Kennedy School, has been researching modern-day slavery, human trafficking and child labor for two decades. He says that although the DRC has more cobalt reserves than the rest of the planet combined, there's no such thing as a "clean" supply chain of cobalt from the country. In his new book, Cobalt Red, Kara writes that much of the DRC's cobalt is being extracted by so-called "artisanal" miners — freelance workers who do extremely dangerous labor for the equivalent of just a few dollars a day.

"You have to imagine walking around some of these mining areas and dialing back our clock centuries," Kara says. "People are working in subhuman, grinding, degrading conditions. They use pickaxes, shovels, stretches of rebar to hack and scrounge at the earth in trenches and pits and tunnels to gather cobalt and feed it up the formal supply chain."

Kara says the mining industry has ravaged the landscape of the DRC. Millions of trees have been cut down, the air around mines is hazy with dust and grit, and the water has been contaminated with toxic effluents from the mining processing. What's more, he says, "Cobalt is toxic to touch and breathe — and there are hundreds of thousands of poor Congolese people touching and breathing it day in and day out. Young mothers with babies strapped to their backs, all breathing in this toxic cobalt dust."

Cobalt is used in the manufacture of almost all lithium ion rechargeable batteries used in the world today. And while those outside of the DRC differentiate between cobalt extracted by the country's high-tech industrial mining companies and that which was dug by artisanal miners, Kara says the two are fundamentally intertwined.

"There's complete cross-contamination between industrial excavator-derived cobalt and cobalt dug by women and children with their bare hands," he says. "Industrial mines, almost all of them, have artisanal miners working, digging in and around them, feeding cobalt into the formal supply chain."

Kara acknowledges the important role cobalt plays in tech devices and in the transition to sustainable energy sources. Rather than renouncing cobalt entirely, he says people should focus on fixing the supply chain.

"We shouldn't be transitioning to the use of electric vehicles at the cost of the people and environment of one of the most downtrodden and impoverished corners of the world," he says. "The bottom of the supply chain, where almost all the world's cobalt is coming from, is a horror show."

Interview Highlights

On how "artisanal" cobalt mines continue to operate in the DRC — despite being illegal

Technically, under the law, there should not be artisanal mining taking place in any industrial mine. And yet, lo and behold, at most of the industrial mines, there is some artisanal mining taking place. In some cases, predominantly artisanal mining is taking place. And the reason is, it's a penny-wage way to boost production. I mean, imagine you're in a part of the world where there are millions of people who barely get a dollar or two a day who are grindingly poor and will accept almost any labor arrangement just to survive. Well, you put them in a tight pit, cram them with 10,000 other people and pay them a couple of dollars, and they'll produce thousands of tons of cobalt per year for almost no wages. And so that's not legal, but it's happening.

On why these conditions are on par with slavery

Imagine an entire population of people who cannot survive without scrounging in hazardous conditions for a dollar or two a day. There is no alternative there. The mines have taken over everything. Hundreds of thousands of people have been displaced because their villages were just bulldozed over to make place for large mining concessions. So you have people with no alternative, no other source of income, no livelihood. Now, add to that the menace in many cases of armed forces pressuring people to dig, parents having to make a painful decision, 'Do I send my child to school or do we eat today?' And if they choose the latter, that means bringing all their kids into these toxic pits to dig just to earn that extra fifty cents or a dollar a day, that could mean the difference between eating or not. So in the 21st century, this is modern-day slavery. It's not chattel slavery from the 18th century where you can buy and trade people and own title over a person like property. But the level of degradation, the level of exploitation is on par with old-world slavery.

On the danger of collapse in artisanal mines

I spoke with many families whose children, husbands, spouses, had suffered horrific injuries. Oftentimes, digging in these larger open-air pits, there are pit wall collapses. Imagine a mountain of gravel and stone just avalanching down on people, crushing legs and arms, spines. I met people whose legs had been amputated, who had metal bars in where their legs used to be. And then the worst of all is what happens in tunnel digging. There are probably 10,000 to 15,000 tunnels that are dug by hand by artisanal miners. None of them have supports, ventilation shafts, rock bolts, anything like that. And these tunnels collapse all the time, burying alive everyone who is down there, including children. It's a demise that is almost impossibly horrific to imagine. And yet I met mothers pounding their chests in grief, talking about their children who had been buried alive in a tunnel collapse. And these stories never get out of the Congo. People just don't know what's happening down there.

On the trafficking of children to work in the mines

There's money to be made in every corner and every direction. And you've got these militias. Sometimes they're called commandos and they will abduct children, traffic children, recruit children from even other parts of the Congo. I met children who had come from hundreds of miles away and have been brought through militia networks down into the copper cobalt mines to dig. And as they dig and earn their dollar or two, that's what funds these militia groups. So children are the most heavily exploited of all the people down there. They're the most vulnerable and oftentimes trafficked and exploited in some cases in very violent circumstances.

On government corruption preventing change

Corruption is a big part of the problem. That's what allows so much of this abuse to persist. And the thing is, imagine the Congo. It's a war-torn, deeply impoverished nation that has been subjected to generations of pillage and ransacking going all the way back, now centuries, to the slave trade. And so when big foreign stakeholders come waving around large sums of money, it's not a long stretch of the imagination to see that there would be corruption. ...

The first democratically elected president of the Congo [in 1960], Patrice Lumumba, made a pledge that the country's immense mineral riches and resources would be used for the benefit of the people who live there. And in short order, within six months, he had been deposed, assassinated, chopped to pieces, dissolved in acid and replaced with a bloody dictator, a corrupt dictator who would keep the minerals flowing in the right direction. So if you don't play ball with the power brokers at the top of the chain and with the Global North, Patrice Lumumba showed what's the outcome, what will happen. And I think that's also a part of this lesson that we need to understand historically, when we talk about things like corruption.

On how China came to own most of the industrial mines in the Congo

China cornered the global cobalt market before anyone knew what was happening. It goes back to the year 2009 under the previous president in the Congo, Joseph Kabila. He signed a deal with the Chinese government for access to mining concessions in exchange for development assistance, a commitment to build roads and some public health clinics, schools, hospitals, things like that — and that opened the door. Before anyone knew what happened, Chinese companies had seized ownership of 15 of the 19 primary industrial copper-cobalt mining concessions down there. So they dominate mining excavation on the ground. And not just that, they dominate the chain all the way through to the battery level. They have about 70, 80% of the refined cobalt market and probably half of the battery market.

On witnessing suffering and trauma

There are some incidents that are just so burned into me that they'll come at me just like a terror, and it's hard. I just hope I've done justice to those stories and to the people who shared their tragedies with me, courageously shared these tragedies with me. I just want their voices [to] reach the world and then the world will decide what to do with the truth and the testimonies of the Congolese people. But if I've done some justice to bringing those voices out into the world that can scarcely function without the suffering of the Congolese people, then it's all worth it. Even the nightmares and the terrors, it's all worth it.

Sam Briger and Joel Wolfram produced and edited this interview for broadcast. Bridget Bentz, Molly Seavy-Nesper and Gisele Grayson adapted it for the web.