Lichens and Radioactive Fallout

There is nothing like a lichen for collecting radioactive fallout. These simple plant forms (Phylum Thallophyta) grow very slowly in the Arctic and collect more of any available radioactive fallout than other plants found there.

Trace quantities of radioactive fallout from Soviet and American nuclear testing prior to 1962 still can be detected in Arctic lichens. Scientists are learning that the radioactive materials provide useful biological tracers to investigate the food chain in the Arctic.

Reindeer and caribou feed extensively on lichen, especially in winter. They, in turn, get eaten by wolves. By following the radioactive tracers from lichen to reindeer and caribou to wolf, one gains knowledge of the details of the Arctic food chain not available by other methods. One result is that the radioactive fallout from the early nuclear explosions probably is not as serious a problem to the food chain as first thought.