Monday, January 21, 2013

The surprisingly mild effects of Chernobyl on wildlife

The explosion and fire [around Chernobyl] spewed the equivalent of at least 20 Hiroshima bombs’ worth of radiation, mostly within about 25 miles of the reactor building. The most radioactive isotopes have long since decayed, and rain has washed the rest into the soil and the food chain. Two of the most persistent isotopes are cesium-137, which chemically mimics potassium, and strontium-90, which imitates calcium in living things. As these isotopes have been taken up by plants, animals, fungi, and bacteria, radioactivity is no longer on the zone, but of it. ...

Roe deer and wild boar caught here in the early 1990s packed more than 2,000 times the safety norms for cesium-137 in meat. Though internal radiation levels have since dropped dramatically, some animals recently tested in Belarus still exceeded safe levels by dozens of times.

But in a surprise to just about everyone, the animals all looked physically normal. The same was true of other species tested—radioactive but normal-looking. The few known exceptions include albino spots and some deformities in barn swallows. ...

Actually, in the early years, when contaminated dust coated everything, researchers found countless examples of the monstrous mutations imagined in 1950s horror movies: malformations, dwarfism, gigantism, strange growths, and, yes, even some glowing.

But those effects were seen only in plants. While Attack of the Giant Leaves doesn’t seem as horrible as the Creature With the Atom Brain, no one has ever found seriously deformed wild animals (or zombies) after the Chernobyl accident. Mutant animals born in the wild die or get eaten before they can be discovered. Whatever the biological costs of radiation to individuals, the fittest survived.

Chernobyl’s abundant and surprisingly normal-looking wildlife has shaken up how biologists think about the environmental effects of radioactivity. The idea that the world’s biggest radioactive wasteland could become Europe’s largest wildlife sanctuary is completely counterintuitive for anyone raised on nuclear dystopias.
--Mary Mycio, Slate, on the post-apocalyptic scene