And so it ends. In our fifth and final column examining the use of backscatter x-ray machines in airport security, S.E. Kramer stays on target by jettisoning tangential issues about privacy and asking, "Will these machines actually make us safer?" For other points of view, check out the previous installments in the weeklong series by our Shift columnists: Peter Suciu, Stewart Wolpin, Stephen Schleicher and Leslie Shapiro.

Naked, shmaked. I'd let anonymous airport workers examine my contours every day of the week if it were likely to stop terrorism on airplanes. The backscatter x-ray machines that the TSA has begun to test in Phoenix have blurred the images for privacy's sake, but if it were up to me, they'd be as clear and revealing as possible. These machines are expensive, so the government might as well get scans that are in focus.

But I digress. As I was saying, nudity is beside the point. Critics who focus on "my body, my body image" arguments are being diverted by false modesty from the real issues at hand: Are the machines are safe, and will they be more effective than our current system?

According to American Science and Engineering (AS&E), the company that manufactures the SmartCheck Personal Screening system, the dose of radiation coming from the backscatter machines is so low that the system is completely safe. In fact, one scan equals only "one percent (1%) of the radiation dose received by the average person on any day of the year."

So can we agree to increase our radiation intake by 1% on a given day to avoid the risk of a seatmate carrying a box cutter? The New York Times, armed with that statistic (provided by the company's marketing department), found doctors to take both sides of the argument. But the 1% figure isn't even accurate. The TSA's press release states that passengers will be asked to go through two scans — one front and one back — before getting on the plane. From day one passengers are getting double the amount of exposure than the company initially promised.

If the AS&E publicity campaign works, then there's no reason that schools, courts and secure office buildings wouldn't replace their current metal detectors with SmartChecks. Pretty soon we might be dealing with a 1% to 2% increase in radiation per year, instead of per flight. Let's not forget that these machines are new, and haven't been tested over long periods of time. Though they're supposed only to emit small amounts of radiation, they may malfunction — the TSA already aborted one trial program because the machines were prone to breaking down.

So the airports are going to see us naked, and they're going to throw some radiation at us. Will it help keep planes in the sky? One telling quote from the Times article: "The x-ray is not strong enough to penetrate much beyond the skin, so it cannot find weapons that may be hidden in body cavities." Does anybody else remember when a would-be parachuter snuck by Empire State Building security wearing a fat suit to hide his parachute, camera and unusual outfit? I only mention him because the SmartCheck system would make it easier to miss someone like that than the current metal-detector-plus-pat-down system, where security personnel actually glance at (and touch, if necessary) something more than the passenger's black-and-white silhouette.

If airports really want to a complete picture, they'll have to shoot more radiation at us to make the system closer to a real x-ray, something that would be demonstrably unsafe for frequent travelers. But as it is now, the SmartCheck has at least this one major flaw that will make it less effective than most airports' screening systems.

So why are we testing it? The SmartCheck isn't supposed to replace the strip search because it's necessarily more accurate than current technology, but because it's faster. The question turns out not to be, what is an acceptable risk (radiation) to take in the name of safety, but what is an acceptable risk to take for speed and convenience.

Besides posing no long-term risks to passengers or airport employees, pat-downs and strip searches have an added advantage over the impersonal x-ray — they give a good transportation security official the chance to ask questions and perform a quick psychological profile. Rafi Ron, the former director of security at Ben-Gurion International Airport in Tel Aviv, has stated that the interview is the most important part of airport security procedures. It cannot be automated.

Some of my colleagues value making the security process quicker. I value making it safer — safer from terrorists and safer for the long-term health of passengers. The TSA should stop spending money trying to find a quick fix, cure-all machine, and instead focus on training security personnel and hiring enough of them to make the system run more smoothly. — S.E.K.

S.E. Kramer is a freelance writer in Manhattan. She's traveled the world as a writer for the Rough Guides, and contributed to Wired, Condé Nast Traveler, and Portfolio.com. In September, she swam across the East River under the Brooklyn Bridge.