In a twisted take on Rudolph’s glowing nose, scientists have found that levels of radioactivity amongst Norway’s reindeer are higher this year than they have been for a long time. Although it’s been nearly 30 years after the Chernobyl nuclear disaster, Norwegian scientists have measured radiation levels in reindeer populations in Central Norway that are more than five times higher than they were when last measured in 2012 (8,200 becquerel per kilo in Sept. 2014 versus 1,500 becquerel per kilo in Sept. 2012). Scientists also measured the levels of radioactivity in sheep populations and found those to be 4,500 becquerel per kilo at maximum. To put those numbers in perspective, 600 becquerel per kilo is the safety limit for human consumption of sheep meat.
“This year is extreme,” Lavrans Skuterud of the Norwegian Radiation Protection Authority told The Local. The cause of the high radiation levels in animal populations this year, however, is not a mystery. “This year there has been extreme amounts of mushroom. In addition, the mushroom season has lasted for a long time. And the mushroom has grown very high up on the mountains.” Mushrooms in Norway are a staple food for animal populations but have the downside of being able to absorb a lot of radioactivity.
Caesium 137, the unstable element used in the Chernobyl plant to generate activity has a half-life of 30 years, so it’s still breaking down after it was released in the 1986 meltdown. Theoretically, the element should break down completely in two years time. “The level of [radioactivity] in the environment still decreases faster than this,” Skuterud told The Local. “Some of it is washed out and most of it is bound to the soil. Only a small part of it is in circulation throughout the food chain. When we watch the values in the grazing animals in autumn, it bounces up and down, and it seems to be everlasting. But the winter values in reindeer luckily show a stable decrease.”
Via The Local