What happened at Chernobyl?

Until the 19th century, the Pripyat River basin on the border between Ukraine and Belarus was wetland and forest. As usual, humans kind of ruined it. They burned down forest for pastureland and cut down trees for timber—or for fuel to make glass and vodka. By the middle of the 20th century, most of that industry was gone, and human-driven reforestation efforts had remade the Pripyat region anew. And then, on April 26, 1986, a nuclear power plant called Chernobyl, on the Pripyat River about 70 miles north of Kiev, blew up and caught fire, spewing radiation across the northern hemisphere.

So that was a big change.

The Soviets ended up evacuating 300,000 people from nearly 2,000 square miles around the plant. The bulk of that area is now called the Chernobyl Exclusion Zone, and the old power plant is now encased in a giant concrete sarcophagus. But what happened to the Exclusion Zone after everyone left is the subject of disagreement in the scientific community. For decades, research in the area said that plant and animal life had been denuded, and the life that remained was mutated, sick. Newer research says otherwise—that plants have regrown, and animal life is even more diverse than before the accident. The Exclusion Zone hasn’t been rewilded so much as de-humaned, more unmanned in folly than anything Lady Macbeth ever worried about. It’s a living experiment in what the world will be like after humans are gone, having left utter devastation in our wake.

It’d be easy to assume that exposing 3 billion humans to clouds of radioactive strontium, iodine, cesium, and plutonium would be a Thanos-snappingly bad thing. Some 134 emergency responders around the plant got acute radiation sickness, but 530,000 recovery workers got high enough doses to be worrisome. Studies are ongoing as to what that did to their bodies.

One effect seems uncontroversial: The more radioactive iodine you get exposed to, the more likely you are to have thyroid cancer and other thyroid problems later in life. Clean-up crew members today have disproportionately more instances of leukemia and other cancers, as well as cataracts. Luckily, radioactive I-131 doesn’t stick around.

A mostly conifer forest west of the plant, where radiation levels were the highest, turned red and then died; it’s still called the Red Forest. But elsewhere? Early studies of birds and invertebrates like insects showed population declines, and later work showed the same for large mammals.

Since the accident, brown bears have colonized—or perhaps recolonized—the Exclusion Zone. In the late 1990s, European researchers introduced the nearly extinct Przewalski’s horse. Bison are thriving there too. The absence of humans seems to have allowed these populations to grow freely.

No human pressure means a diverse ecosystem thrives, but radiation could tamp down that ecosystem’s ebullience.

The question is one of balance, or competing lifelines—no human pressure means a diverse ecosystem thrives, but radiation could tamp down that ecosystem’s ebullience. One of the methodological problems, though, is that no one’s really sure exactly how much radiation is there. Some people think that the radionuclides left on the ground are trapped in the soil; others think that animals traipsing through the forests could carry those particles with them and transport them to new locations. Even ascertaining the radiation level is a problem. Researchers from the University of Bristol have tried using quadcopter drones to map them; Beasley’s team is deploying GPS collars for animals with built-in dosimeters to try to answer, finally, the actual doses that critters pick up.

Those differences have knock-on effects that get to the heart of why this place is so hard to study. In the Red Forest, for example, the conifers that died were replaced by deciduous trees that could tolerate radiation better, but their leaf litter is less acidic, changing the microorganisms that live in it.

This all matters because the Exclusion Zone is all but unique. There are only a few other places on Earth that used to have humans but no longer do. They become models for a different kind of world, even if—or maybe especially because—two of those places, Chernobyl and Fukushima, are also radioactive. That’s important too. If you believe that nuclear power will be one of the key ways to produce energy without exacerbating Earth’s ongoing climate crisis, it’s important to know just how bad an accident at one of those nuclear power plants could get. Nuclear is a green, or at least green-ish, source of power—it requires cold water (which it then heats up) and creates a certain amount of waste, but that might be tolerable if you’re also willing to put up with the occasional risk of a Chernobyl or a Fukushima until someone reengineers these systems to be safer.

Oh, and that’s not the only reason to be thinking about climate change and Chernobyl. In 2015, two wildfires in the Exclusion Zone re-aerosolized radioactive particles in their smoke and carried them aloft, dosing parts of Europe all over again—at about the level of a medical x-ray. In fact, says Møller, the Exclusion Zone is constantly plagued by fire. And climate change has already increased the likelihood of fires in abandoned urban and peri-urban areas in Europe. Which means one of the lasting legacies of the Exclusion Zone extends far beyond its boundaries: climate change-induced radioactive wildfires. But history as it seems shows that whatever happens, life has a way of still going on.

Check out my related post: Would you go to Mars?

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