A Canadian man undergoing treatment for prostate cancer ran afoul of airport security while traveling to the United States in October 2003. According to the Canadian Medical Association Journal, the businessman was passing through customs when a guard with a pager-sized radiation detector accosted him. "He was taken into a separate room where he was asked to stand against the wall and refrain from speaking while workers examined his luggage," the man's doctors wrote in a letter to the journal. "Eventually, he was asked why he kept setting off the radiation detector." The man then had to explain to a crowd of strangers that doctors implanted radioactive iodine seeds in his prostate gland to kill cancer cells. It was, no doubt, a mortifying experience for the Canadian traveler, but it shows how seriously the United States takes guarding against and, if need be, cleaning up dirty bombs. Detecting a Dirty Bomb Besides beefing up security at airports, the Bush Administration unveiled in 2003 its Megaports Initiative (in addition to its existing Security Container Initiative) to provide radiation detection equipment to key overseas ports, including the one in Haifa. This year, the Megaports project got $74 million. And there is no shortage of companies to produce the radiation detectors. Firms like Canberra, Thermo Electron Corporation and Rotem Industries, Ltd., make devices in all sizes, from beeper-like boxes to high-powered portals that can be placed along roads, railways or sea ports. Berkeley Nucleonics in California even pitches a network of GPS-enabled cellular phones fitted with detection devices. "You have a scientist in one central location monitoring all these dumb nodes," explains account manager Rob Rao. "And if there is a problem, he can tell exactly where it is happening." Stripped of all their fancy wrappings, there are actually just two core technologies on the market: the clickety Geiger-Muller counter and the scintillation detector, both invented before 1910. Of the pair, the scintillator is 50-100 percent more sensitive thanks to a photomultiplier tube, developed in 1944, that boosts the light-based signal released by an excited organic crystal. "When you are far away from the suspected source, you want to use a scintillator because it's very sensitive," says Itzhak Orion, a radiation detector expert at Ben-Gurion University. "But once you already have fallout, you want to use a Geiger counter." Decontaminating People and Property Fallout - no one wants to think about it. Still, the US Center for Disease Control and Prevention (CDC) has posted straightforward instructions on its Web site on what to do in case of a radioactive incident. For instance, people are advised to cover their noses and mouths with a rag and get inside a building whose walls and windows are still intact. Once inside, those exposed to radioactive dust should close the windows and turn off the air conditioner, heater and vents. They should then take off their outer layer of clothing and with the cloth, seal it in a plastic bag if available. Showering or washing with soap and water is strongly recommended. The CDC's Strategic National Stockpile also includes drugs to treat radiation poisoning following a dirty bomb explosion, such as DTPA (flushes americium and plutonium out of the body), Prussian Blue (traps cesium in the intestine) and Filgrastim (speeds up white blood cell production). But it's one thing to treat evacuees. What about the area around ground zero? "A dirty bomb won't bring a city to its knees," says Ivan Oelrich, a nuclear physicist with the Washington-based Federation of American Scientists. "But you might have buildings or a subway station contaminated." Ultimately, some buildings will have to be sandblasted, others torn down - not a very attractive set of options for treasured national monuments or skyscrapers. So in July 2004, David Kaminski, a nuclear engineer at the government-funded Argonne National Laboratory in Illinois, came up with a new way of cleaning up after a dirty bomb. The idea is to spray affected areas with a wetting agent and a polymer gel similar to material found in disposable diapers. When exposed to the agent, radioactive particles embedded in the surface free up, and the polymer gel then absorbs and traps the particles, which can then be vacuumed away.