How Dangerous are Low Doses of Radiation?
Radiation is everywhere. Rocks produce a natural form called radon. Anyone who has had a chest or dental X-ray has been exposed to man-made radiation. And highly sophisticated medical imaging techniques are used to treat life-threatening deformities or diseases. Yet most of us are frightened of radiation because we've heard about the terrible effects of high doses experienced during atomic bomb explosions or nuclear reactor meltdowns. This level of exposure, however, is never even approached during the controlled use of radiation where strict regulations are in place to ensure safety. Still the question remains: Just how dangerous are low doses?
Canada Research Chair Dr. Carmel Mothersill is a radiobiologist who has studied low-dose radiation effects for several years. In her research, she studies the effects of low-dose exposures to cells derived from humans and other species. She is interested in the long-term changes in the behaviour of cells; changes, for example, in how they grow and how they communicate. The information derived from her research helps put radiation risks in context given the benefits of the medical use of radiation. In addition her research is used to help detect potential problems by using sensitive tests that employ cultured cells and small tissue explants and do not involve experiments on animals.
Dr. Mothersill's research suggests that low doses of radiation have very different effects compared to high doses. Cells appear to be able to adapt to low doses and to organize cell and tissue responses through sophisticated communication systems. The death of one or two cells in the population, which could be a consequence of low-dose exposure, is therefore not a problem for the tissue. As she explores this issue, Dr. Mothersill is also looking at the relative sensitivities of individual humans and non-human species to low-dose exposures to see if any are extra-sensitive and whether exposure to a little radiation is dangerous.