Resumen de Chernobyl's future hangs in balance
Plans to turn the Ukrainian exclusion zone into a nature reserve are under threat from the nuclear industry, which wants to dispose of high-level radioactive waste here. The battle may soon be settled as decisions are made ahead of the 30th anniversary of the world's worst nuclear disaster, on Apr 26. On one hand, things are improving. The radioactivity levels are falling. This year marks the half-life of the two most dangerous isotopes released that are still present: caesium-137 and strontium-90. That means just half the amount of these isotopes remains in the region, the rest having decayed. Each emits beta and gamma radiation as it decays, which can penetrate human skin. Most of the exclusion zone now has radioactivity levels for caesium-137 that are below 500 kilobecquerels per square meter, says Jim Smith of Portsmouth University, UK, who studies the environmental impacts of the disaster. He says this is a safe level of exposure, provided people don't eat mushrooms and berries, which concentrate radioactivity.
