SOURCE: Phys.org

DATE: April 10, 2019

SNIP: Radioactive fallout from nuclear meltdowns and weapons testing is nestled in glaciers across the world, scientists said Wednesday, warning of a potentially hazardous time bomb as rising temperatures melt the icy residue.

For the first time, an international team of scientists has studied the presence of nuclear fallout in ice surface sediments on glaciers across the Arctic, Iceland the Alps, Caucasus mountains, British Columbia and Antarctica.

It found manmade radioactive material at all 17 survey sites, often at concentrations at least 10 times higher than levels elsewhere.

When radioactive material is released into the atmosphere, it falls to earth as acid rain, some of which is absorbed by plants and soil.

But when it falls as snow and settles in the ice, it forms heavier sediment which collects in glaciers, concentrating the levels of nuclear residue.

As well as disasters, radioactive material produced from weapons testing was also detected at several research sites.

One of the most potentially hazardous residues of human nuclear activity is Americium, which is produced when Plutonium decays.

Whereas Plutonium has a half-life of 14 years, Americium lasts 400.

“Americium is more soluble in the environment and it is a stronger alpha (radiation) emitter. Both of those things are bad in terms of uptake into the food chain,” said Clason.