OK, I've had just about enough of the stupid statistics being put out by the FDA regarding full body scanners at airports. I'm not sure why everyone is behaving as if such a scan is a singular event in a year.  One hears about how such a small dose compares against the annual safe dosage and yet does it occur to no one that many people fly more than once per year?

The stupidest comparison was an article which asked people to consider the number of mrems absorbed by someone smoking 5 cigarettes.  I'm not sure if that was supposed to make anyone worry less or worry more (after all cigarettes are usually treated as the most toxic substance known to man).  

"Those worried about the 0.001 mrem that a person receives from backscatter airport security scans each way on a round-trip should consider that a person who smokes five cigarettes a day inhales about 1,325 mrem a year ..."

The troublesome bit regarding the full body scanners is the presumption that they will improve security, which has not been demonstrated in any capacity.  Therefore the question that remains is whether there is any level of radiation that is harmless.  If not, then why should we allow gratuitous use of x-rays?

Many people will have multiple passes through security, as well as multiple plane flights.  On the flight itself, one absorbs a larger amount of radiation due to cosmic rays, so it is a reasonable question to ask why ANY additional radiation should be allowed.  After all, if this were a risk/benefit analysis, we would certainly expect an answer to any question of what benefit is being derived from such an increase (even if small) in risk.  

"...the typical New York City-to-Los Angeles trip in a commercial airplane exposes a person to about 2 to 5 millirem (mrem) ..."

"According to Food and Drug Administration standards, no individual who is scanned before flights is allowed to receive more than 25 mrem in a 12-month period. But there's little chance anyone, even a pilot, would reach that threshold: Doing so would take 25,000 scans in one year."

What's wrong with this picture?  It shouldn't take a "rocket scientist" to see that 3 to 6 flights already exceeds the annual dosage, so unless I'm missing something it seems that this calculation is beyond all the "experts" at the FDA.

The actual FDA annual radiation dosage is 100 mrem (from all man-made, non-medical sources) and flight crews ARE monitored and regulated regarding the amount of exposure to which they are subjected.  Passengers are not monitored, since that is considered a voluntary act so no records are kept regarding the risk to passengers. What is of note, is that this is radiation over and above that to which you may already be exposed from natural sources.  

All in all, this entire conversation about body scanners has been a series of misdirections and misleading issues.  It should be obvious that a single body scan isn't going to cause cancer.  It is, however, irresponsible for any scientist to climb on this bandwagon knowing that this isn't going to be the reality of how it is implemented.  It is equally irresponsible (if not stupid) to fail to consider all the other sources of radiation to which we will be "harmlessly" exposed.  It should be clear that each "harmless" exposure can be cumulative until it becomes harmful if we fail to consider the impact on the way people actually live.

For your entertainment: http://hubpages.com/hub/Radiation-Exposure