Health consumers are largely naive about radiation and other risks that come with full-body and other screening tests marketed by private clinics, a University of Victoria health policy researcher says. Alan Cassels, co-author of a recent report published by the Canadian Centre for Policy Alternatives, said people seem to think early detection of any disease is safe and always a good thing if it is under the guise of so-called preventive medicine. “But offering for sale [for up to $2,500] heart, lung or full-body scans to healthy people with no symptoms is questionable, controversial, unregulated and not even recommended by professional associations of radiologists,” he said. Apart from radiation exposure, people can receive false positive findings and then be subjected to further medical tests that are usually done in the public medicare system. It is estimated that for every 100 people who undergo a full-body CT scan, 30 to 80 will be told about an anomaly that needs further, sometimes invasive, investigation but that turns out to be a false alarm, according to the report. CT exams provide detailed images of internal organs and help doctors make diagnoses and guide medical treatment decisions. But they expose patients to a higher radiation dose than most other imaging tests such as plain X-rays. No one in Canada collects data on the number of scans done in the private system.