Radiation and risk: Is it time for a regulatory threshold dose?

Abstract

This editorial follows somewhat from Madhava Bhat’s guest editorial published in the Sept 2010 issue entitled ‘‘‘‘Fear of radiation’’ is frightening’’ [1]. As Madhava suggests, there is a heightened level of fear in the general community regarding radiation, and this is not just confined to ionising radiation (IR) but also non-ionising radiation (NIR), such as electromagnetic fields and mobile phones. I am not going to discuss NIR here except to say that I believe this area also has some worrying developments from a regulatory perspective, and in particular the use of the precautionary principle where there is a very limited scientific evidence of a biological effect. It is understandable why the general community fears radiation. For instance, you cannot see it or feel it, but due to the sensitivity of detectors we can measure the tiniest amount of it. Over the last 60 years or so, we have been bombarded with images of atomic bombs, people in ‘‘radiation suits’’ and pictures of the known damaging effects of high dose radiation. In addition, images of Homer Simpson ‘‘working’’ in the Springfield nuclear power plant, and the subliminal messages found in many of our comic books suggest that radiation will mutate you into a superhero or villain. Currently, there approximately 221 comic characters who’s powers originated from radiation [2]. As well as the images, there are many conflicting reports or opinions regarding the biological effects of radiation and these are often based on either some ideological or political belief or differences within the scientific and regulatory community itself. This situation is not helped by the current media cycle of unbalanced reporting; often with farleft or far-right political views getting more publicity due to their controversy rather than the facts. As a radiation regulator, I often encounter people who are unaware that they are exposed to background levels of radiation from cosmic, terrestrial and internal (body) radiation sources. Many also don’t know that life has evolved on Earth in which natural background radiation levels some 3.5 billion years ago were about three times higher than they are now [3]. For some reason scientists and regulators have failed to remind the general community, or have been unable to get the message across, about the basics of radiation and that it’s a natural phenomenon. Although the population is ‘‘bathed’’ in background radiation, the fact remains that most will only ever receive a small additional radiation dose from the activities they undertake or the medical procedures they require. The only time a person is likely to be exposed to high or dangerous doses of radiation is when they are undergoing medical treatment e.g. radiotherapy or involved in a radiation incident. However, what is deemed ‘‘dangerous’’ depends on what side of the Linear No Threshold (LNT) fence you sit on! A. M. Hooker (&) Faculty of Health Sciences, School of Medicine, Flinders University, Adelaide, SA 5042, Australia e-mail: tony.hooker@epa.sa.gov.au