THE threat posed by the Sellafield nuclear reprocessing plant in Cumbria, UK, has extended through the Arctic Ocean into the waters of northern Canada. According to a new Canadian study, the radioactive contamination, which had not been previously picked up so far from Britain, is having a bigger impact on the Arctic than the Chernobyl accident. The data collected from seawater samples show that a plume of iodine-129 from Sellafield has leaked into Siberia to the north-western shores of Canada at a depth of about 200 metres.

The magnitude of radioactivity in the plume is "greater than the background level from weapons fallout", according to Mike Bewers of the Bedford Institute of Oceanography in Nova Scotia, who led the research. Per Strand of the Norwegian Radiation Protection Authority, says that the Sellafield plant has released 40,000 billion becquerels of caesium-137, of which around 15,000 billion becquerels have reached the Arctic. This is between two and three times the contamination from Chernobyl, which is reaching the Arctic via the Baltic and the North seas.