OverTheGeicoE writes: CNET has a story on DHS' whole car X-ray scanners and their potential cancer risks. The story focuses on the Z Portal scanner, which appears to be a stationary version of the older Z Backscatter Vans. The story provides interesting pictures of the device and the images it produces, but it also raises important questions about the devices' cancer risks. The average energy of the X-ray beam used is three times that used in a CT scan, which could be big trouble for vehicle passengers and drivers should a vehicle stop in mid-scan. Some studies show the risk for cancer from CT scans can be quite high. Worse still, the DHS estimates of the Z Portal's radiation dosage are likely to be several orders of magnitude too low. 'Society will pay a huge price in cancer because of this,' according to one scientist.