They say that five sieverts of radiation is enough to kill you, so I was curious to see the reading on my Russian-made dosimeter as our tour van passed into the exclusion zone—the vast, quarantined wilderness that surrounds Chernobyl. Thick stands of pines and birches crowded the roadside as our guide reminded us of the ground rules: Don’t pick the mushrooms, which concentrate radionuclides, or risk letting the contaminants into your body by eating or smoking outdoors. A few minutes later we passed the first of the abandoned villages and pulled over to admire a small band of wild Przewalski’s horses.
Twenty-eight years after the explosion of a nuclear reactor at Chernobyl, the zone, all but devoid of people, has been seized and occupied by wildlife. There are bison, boars, moose, wolves, beavers, falcons. In the ghost city of Pripyat, eagles roost atop deserted Soviet-era apartment blocks. The horses—a rare, endangered breed—were let loose here a decade after the accident, when the radiation was considered tolerable, giving them more than a thousand square miles to roam.
I glanced at my meter: 0.19 microsieverts per hour—a fraction of a millionth of a single sievert, a measure of radiation exposure. Nothing to worry about yet. The highest levels I had seen so far on my trip to Ukraine were on the transatlantic flight from Chicago—spikes of 3.5 microsieverts per hour as we flew 40,000 feet over Greenland, cosmic rays penetrating the plane and passengers. Scientists studying Chernobyl remain divided over the long-term effects of the radiation on the flora and fauna. So far they have been surprisingly subtle. More threatening to the animals are the poachers, who sneak into the zone with guns.