THINKING of having one of those full-body scans? You will be exposing yourself to as much radiation as many Hiroshima victims received.
In a full-body CT scan, a series of X-rays is used to build a detailed picture of the entire body. Many private clinics now offer CT scans, at a cost of up to $1000, as a way of picking up problems such as cancer or heart disease. 鈥淚t is touted as the equivalent of your annual physical, but non-invasive,鈥� says David Brenner of Columbia University, New York, who has studied victims of the Hiroshima and Nagasaki blasts.
The radiation dose can be 500 times that of a standard X-ray, which Brenner calculates is almost as much as received by Hiroshima victims around 2 kilometres from the epicentre of the blast. Based on the consequences they suffered, he concludes there is a 1 in 1200 chance of a scan causing cancer (Radiology, vol 232, p 735).
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Having a scan every year, as some clinics suggest, makes the risk mount up. After 30 years of scans, there will be a 1 in 50 chance of getting cancer as a result. Even the claimed benefits of scanning are questioned by some researchers, who say they throw up many false positives, meaning people undergo unnecessary investigations and stress.