New Scientist, October 28, 2006
Tougher controls on the slaughter of sheep have been imposed in Norway after they were found to be contaminated with unusually high levels of radioactivity from the Chernobyl disaster in 1986.
The Norwegian Radiation Protection Authority (NRPA) says the problem has arisen because the sheep have feasted on an unusually large crop of mushrooms, which were more plentiful than usual because of wet weather. Previous research has shown that fungi take up more radioactivity from the soil than grasses or other plants.
Could mushrooms like these Norwegian ceps also be dangerous to humans?
There are 36 areas of upland Norway where Chernobyl contamination still requires controls on sheep. According to the NRPA, levels of caesium-137 from the Chernobyl disaster reached 7000 becquerels per kilogram in sheep this year, more than twice maximum levels in previous years.
Farmers can reduce the level of radioactivity in sheep by giving them non-contaminated food for a month before slaughter. For some farmers, this period will now have to be doubled to reduce caesium-137 levels to below Norway’s safety limit of 600 bq/kg.
Per Strand, the NRPA’s head of environmental radioactivity, stresses that the precautions mean that lamb on the market is safe to eat. He says, though, that the discovery of such high levels of radioactivity so long after the Chernobyl accident came as a surprise.
“No one at the time expected contamination to be so high more than 20 years after the event,” he says.
From issue 2575 of New Scientist magazine, 28 October 2006, page 7