In the spring of 2016, journalist Fred Pearce spent an afternoon drinking what he suspected was radioactive vodka, flavored with herbs grown near the site of Chernobyl’s 1986 nuclear disaster. He was visiting a settler who had returned to live in his home within the 18-mile radius around Chernobyl that’s so heavily contaminated children still aren’t allowed to live there.  

“I trusted that probably a couple drinks would be all right, but he’d been drinking this stuff for a long time,” says Pearce, who visited this self-settler in Chernobyl while researching his new book Fallout: Disasters, Lies, and the Legacy of the Nuclear Age. “It was a bizarre experience. All I can say is however radioactive he is, he’s still alive and seemed pretty fit to me.”

Pearce’s visit to Chernobyl is just one of his stops on a world tour of nuclear disasters and cleanups, chronicled in his book Fallout. Published by Beacon Press, the book investigates the toxic legacy left behind by the bombs dropped on Hiroshima and Nagasaki, the race to build more nukes, and the ongoing challenge of dealing with the nuclear energy industry’s waste. “It’s a pretty messy legacy, not least because most of the waste disposal problems created in the heyday of nuclear power haven’t been solved,” Pearce says.

The book originated as a story about just one site: “the heart of the British nuclear industry,” called Sellafield, Pearce says. It’s where plutonium was produced for the first British bombs, and it continues to reprocess waste produced by nuclear power. Back in the 1980s, when Pearce was a writer and editor at New Scientist magazine, “we had stories nearly every week at some new scandal down at Sellafield,” he says. So he went back to see what was going on there now. “Many of the buildings that hold the [waste] now crack, leak, corrode, sprout weeds, and accumulate dark radioactive sludge,” he writes in Fallout.

That gave him the idea: “There was a global effort to be done on the same lines, going back to those places that made headline news, that we don’t talk about much anywhere, and figure out what’s happened.” In many of these places — like Plutonium Mountain in Kazakhstan, where the Soviet Union conducted nuclear tests, or Hanford, where the US made plutonium for nukes — the waste is still there.

The Verge spoke with Pearce about the legacy of nuclear technology, nuclear disasters, and what we still don’t know about radioactive risks.

This interview has been edited for clarity and brevity.

You talk about the messy legacy after more than a half century of nuclear power — both military and civil — why are we facing this toxic legacy?

We just never got to grips with the problem. Partly that’s because of environmentalists and other people who just said, ‘We don’t want this waste in our backyard,’ which is perfectly understandable. But the result is that the waste is in everybody’s backyard. In the US, 35 states have stores of spent fuel from nuclear reactors, with nowhere permanent for them to go. Nobody wants it. Nobody can agree on a site because partly we’re frightened of radioactive waste, understandably so, and partly the industry has just not organized itself to have a concerted effort to deal with the problem. Nobody has wanted to face up to this emerging legacy, which we’re now just passing on to future generations.

In your book, you take this round-the-world tour of nuclear disasters throughout the history of nuclear technology. What was it like doing this research?

I was surprised at how people were willing to take me round and show me. I contacted pretty much the most secretive Russian nuclear place behind the Urals, a state-owned company called Mayak, which is a closed city. I wasn’t allowed to visit the closed city. But I could turn up and they would come down the road and talk to me outside the boundaries of the city and talk me through their work, the nasty accidents, and the chronic pollution problems they’ve had there over the years.

I went to the exclusion zone around Chernobyl, [the site of a major nuclear] accident in 1986 and again people were willing to take me round, and to talk me through the radiological hazards there, and show me the extraordinary amount of wildlife that is now in that exclusion zone. I found similar things around the Fukushima accident area in Japan, where the powerstation was overwhelmed by the tsunami in 2011 and again there was a big accident there. And there, again people were willing to show me around, and I could take my Geiger counter round and measure the radiation in various places. So there was quite a lot of candor. I was surprised by how much I was able to see.

Did you get any weird looks, walking around with your Geiger counter?

Well no, everyone walks around with their Geiger counter, nobody’s stupid. What you discover is that the radiation levels vary hugely. So you’re walking down the street and the radiation levels, [as] you’re waving your Geiger counter, are pretty low. But sometimes you put it down to a piece of vegetation in a gutter, or in the road, and the levels start soaring. So it’s very variable. In the Fukushima area, or in Japan, the authorities have put up public radiation measurement devices and they have big displays. So as you drive down the road you can see instantly what the radiation levels are.

What really sticks in your memory from your tour of nuclear disasters?

The exclusion zone in Chernobyl, and the way that wildlife has come back into that area, because that was the world’s worst nuclear accident by a long way. You can’t really conceive of a worse accident. The top was blown off of this reactor and all the fuel was exposed, and it was burning, and it burnt for days. Large numbers of people were killed just trying to put out the fires, and the radiation spread across Europe. And, of course it spread in the greatest quantities in the area immediately around the power station. So this exclusion zone, the radiation is too high to be able to stay there for a long period. But wildlife was coming back. There were packs of wolves, there were lynx. I didn’t see any, but there are bears there. Some people say they can see DNA damage to the wildlife because of the radiation, but the bottom line seems to be that wildlife loves it because there are not many people there.

What do we know about the risks of radiation in the disaster sites?

They vary. It’s a kind of complicated picture, made more complicated by people’s fears about radiation. My guess is that sometimes our fears are more severe than they need be. But it’s kind of understandable. In areas where there have been nuclear accidents, people rather understandably don’t trust the nuclear authorities because there was an accident, things went wrong. So if the nuclear authorities come along and tell you, ‘Well it’s safe to go back now,’ not many people are willing to accept their reassurances. One of the things that you find, therefore, is a lot of psychological trauma in these areas.

How much radiation is safe for a person to be exposed to?

Depends who you talk to. I was amazed to discover that there is no consensus in the scientific community about whether there’s a safe dose. There seem to be two camps. One of them believes that even very low levels of radiation do carry risks, and risks to very large numbers of people, potentially. But there’s another school of thought that says, well really there seems to be a threshold. The body seems to be able to cope with small amounts of radiation. We’ve always lived with background radiation from entirely natural sources. So maybe there’s a threshold — and some people have tried to establish the threshold. But there’s literally no consensus on it: there are two schools of thought, and they haven’t found a way of resolving it.

What does your research tell us about the future of nuclear power?

It’s a dying industry. What we are left with is the legacy of radioactive waste from half a century and a bit more of nuclear power and some of the military activities. That is a legacy that we are visiting on future generations, because this stuff is going to stay radioactive for very long periods of time. So while the individual risks of radiation from some of this stuff is probably a bit overblown, it doesn’t mean we don’t have to sort out the problems with this waste. Anything containing plutonium is dangerous, and dangerous over a long period of time. We’ve simply got to sort out that problem of finding safe ways of disposing of this, which basically means making it safe and burying it underground in a sort of solid form. And we haven’t done it, and we don’t seem to be politically able to organize ourselves to do it. So it’s a very unpleasant legacy which we are leaving.

In the book, you talk about environmental contamination from weapons manufacturing and from nuclear power. Are you worried that you’ve conflated the legacies of the two?

No. The legacies are very similar, because the technologies are very similar. Nuclear reactors were developed to manufacture plutonium for bombs. It was clear that those reactors produced very large amounts of waste heat, which was a byproduct that wasn’t useful initially, but people realized very quickly that so much waste heat being produced in the reactors could be turned into power. And therefore, after the bomb-making of the 1940s and the 1950s, people turned these reactors of essentially the same design into reactors whose primary purpose was to produce energy rather than plutonium. But the reactor technology is essentially the same. You can turn the waste products that you produce out of every civilian reactor, you can reprocess it and turn it into plutonium. So even if the economic or public purpose of military and civilian reactors are different, the technology is the same and the waste products are the same.

What do you hope a lay audience takes away from your book?

I don’t want to tell people what to think about nuclear power. There has been a lot of hyperbole on both sides about nuclear technology, it almost brings out the worst in us as citizens. So I just wanted to go out there as a reporter and basically tell people what I found. I’m giving as dispassionate as I can a story about what I found when I traveled through the history of nuclear power over the last 60 to 70 years, its landscapes. The secrecy has been one of the Achilles’ heels of the industry, both military and civil. We find it very difficult to be honest on either side about what the real risks are, or to investigate dispassionately what the risks are. So it’s a very polarized debate.

What’s the strangest story that came out of your research?

What I found really weird was going through the prairie landscapes of Colorado, visiting the silos, where America’s missiles are still down there. I don’t know who they’re programmed to obliterate if they get launched, but they’re still there in very large numbers. And you go through these agricultural landscapes, and you go onto somebody’s farm, and there’s a little corner of one field where there’s a steel fence around, and underneath there’s a missile ready to blast off and head across the planet and hit Moscow, or Pyongyang, or wherever. That’s just scary, because we’ve almost got used to this. We don’t talk about the Cold War anymore, but these weapons are still there, and they’re still armed. Especially in the current political climate, we’ve almost normalized a world where we can still obliterate ourselves in huge numbers.