With very low levels of naturally occurring radioactivity in the salt deposit, and with its great depth, the WIPP underground may be an ideal location to study the effects of extremely low dose rates on biological systems. Recent technological advances in cellular biology and genomics have potentially made it possible to understand how lose doses of ionizing radiation affect living systems.
One experimental approach to understanding how low doses affect living things is to incrementally add additional radiation dose beyond that nominally received as background to carefully monitored organisms, and evaluate their response. A second approach may be to lower the background dose "enjoyed" by all organisms to very low levels and evaluate the outcome. The low dose environment of the underground setting at WIPP could greatly facilitate this latter possibility.
All life on Earth has been bathed in background radiation since the dawn of time. This ionizing radiation comes in approximately equal amounts from cosmic rays, terrestrial radioactivity, and internally deposited naturally occurring radioactive material in the organism itself. Using specially designed shield chambers, it is possible to eliminate dose from all terrestrial sources and some of the cosmic rays. However, lowering the background dose to organisms even further requires going deep underground and the use of shielding. Underground, the rest of the cosmic ray doses are eliminated and the low content of Uranium, Thorium and Potassium in the host salt makes shielding easier. An additional consideration is the naturally occurring radioactive rare gas, Radon. Radon is produced during the decay of the Uranium and Thorium. Since these are already very low compared to other crustal rocks, the amount of Radon present is also very small. At such small levels, controlling its contribution to the background dose during an experiment is much more reliable and inexpensive.
Oldest Life on Earth Found in WIPP Underground
As a possible example of how low dose conditions may affect biological organisms, consider the recent discovery of ancient bacteria in brine inclusions of the salt formation at WIPP. Researchers cultivated a colony of an heretofore unknown species of halophillic bacillus from spores inside salt deposited at the end of the late Permian (some 220-250 million years ago). This discovery has pushed the envelope for resurrecting living things back in time by a factor of about ten, and allows the previously unknown bacteria (Bacillus species, designated 2-9-3) to lay claim to the title of the "oldest known organism". Learn more about these Methuselan bacteria and possible profound implications about the origin of life.