Questions raised over effectiveness of X-ray scanning

HOW GOOD is the X-ray as a stand-alone security control under the Part 108 regulations? The question of whether conventional X-ray is good enough to be the only security control used by regulated agents and air carriers has been the subject of lengthy, and sometimes heated, debate, according to Bob Garbett, of Baasa. “There are essentially two factions in this debate,” he told FTW. “On the one side, the opinion is that X-ray is the most efficient and practical non-invasive search technology that we have currently available – and is used as a primary search technology in certain countries.” But there is an equally vociferous opposition viewpoint, he added, that X-ray is grossly defective when used on air cargo. “For most, if not all, the X-ray machines in commercial use in SA,” said Garbett, “the penetration depth through steel is between 29-millimetres (mm) and 70-mm. And, through a couple of millimetres of lead, the penetration is nil.” He also pointed to the restrictive sizes of X-ray monitoring units. “The size of the X-ray archway is approximately 1.5-m x 1.5-m,” he said, “which precludes probably 40% or more of cargo passing through the X-ray machine.”