Journalism in the Public Interest

New Report Likely to Fuel Debate Over TSA Scanners

A new report from the inspector general of the Department of Homeland Security is likely to fan rather than extinguish the debate over the safety of X-ray body scanners, known as backscatters, deployed at airports across the country.

Photo by Scott Olson/Getty Images

Feb. 28: This post has been updated.

A new report from the inspector general of the Department of Homeland Security is likely to fan rather than extinguish the debate over the safety of X-ray body scanners deployed at airports across the country.

Sen. Susan Collins, R-Maine, and other lawmakers have called on the Transportation Security Administration to conduct a new, independent health study. No such tests were carried out for the report, which instead relied on previous radiation tests, most of which have been available on TSA’s website.

"This report is not the report I requested," Collins said in a statement to ProPublica. "An independent study is needed to protect the public and to determine what technology is worthy of taxpayer dollars."

The amount of radiation emitted by the body scanners, known as backscatters, is “negligible” and “below acceptable limits,” according to the report obtained by ProPublica and scheduled for public release on Tuesday.

But the 28-page report also notes that not all TSA screeners have completed required radiation safety training. Inspectors found inconsistencies in how the machines are calibrated to ensure radiation safety and image quality. And the TSA made more than 3,500 maintenance calls in the first year the scanners were deployed, meaning that, on average, each machine needed service more than once a month.

X-ray body scanners became part of routine screening at airports nationwide after the underwear bomber tried to blow up a plane on Christmas 2009. The machines emit very small doses of ionizing radiation, the type of radiation that has been shown to cause cancer.

Radiation experts who have been critical of the TSA acknowledge that the machines emit only tiny amounts of radiation. But they say that as tens of millions of airline passengers are exposed for routine screening, it is likely that a few of those people will develop cancer from the machines.

ProPublica reported in November that the TSA has glossed over the scientific nuance in declaring the machines safe, that the United States was almost alone in the world in deploying the X-ray scanners and that the Food and Drug Administration went against its own advisory panel in allowing the machines to fall under voluntary standards.

A day after the story, TSA administrator John Pistole agreed to a request by Collins to conduct a new, independent health study of the scanners. But a week later, Pistole backtracked saying this report, then still being finalized, would render a new study unnecessary.

“We believe the report fully endorses TSA’s extensive efforts to keep the traveling public safe,” Pistole said in a response letter that was attached to the report. “As a result of intense research, analysis and testing, TSA concludes that potential health risks from a full-body screening with a general-use X-ray security system are miniscule.”

The report notes that an airline passenger would have to be screened 47 times per day to reach the annual radiation dose limits set by professional organizations. The inspectors said that no accidental radiation overdoses have ever occurred from the scanners.

The inspector general’s office did not test the machines but instead reviewed radiation measurements taken by the manufacturer’s maintenance contractors and Army health physicists.

The report does not address the potential health effects of exposing tens of millions of people to low-dose radiation. Nor does it weigh the risk and benefit against a safer type of body scanner that uses the electromagnetic waves, which have not been linked to cancer. That machine, known as a millimeter-wave scanner, is already used by the TSA in dozens of airports, such as Atlanta Hartsfield, Dallas-Fort Worth and San Francisco.

The report also raises questions about maintenance. From May 2010 to May 2011, the TSA made 3,778 service calls in response to mechanical problems with the backscatter units. That works out to 10 calls per day, or an average of more than 15 calls per machine per year. But the report noted that only 2 percent of those calls were significant enough to require a radiation test.

Although the inspectors did not find any scanners that had been calibrated improperly, they found that some airports calibrated the machines less frequently than others and recorded the results differently.

The inspector general recommended that the TSA develop a process to ensure that all screeners receive radiation safety training. Several screeners told the inspectors that they were unable to complete online training because of computer delays and time constraints associated with doing their jobs.

Last month, a group of six Republican and Democratic senators on the homeland security committee introduced a bill that would require the TSA to post signs about the radiation at the front of security checkpoints and to hire an independent laboratory for a health study. House Republicans filed a companion bill in mid-February.

Officials in Broward County, Florida, recently voted to demand more information from the TSA on the safety of scanners in use at Fort Lauderdale-Hollywood International Airport. They are now reviewing the agency’s response.

And in Alaska, a state lawmaker who decided to take a ferry back from Seattle rather than undergo a pat-down required to fly, last week proposed bills to outlaw the use of body scanners in that state and to study the health effects of airport screening.

it is likely that a few of those people will develop cancer from the machines.

No, it is not “likely”. The Linear No Threshold model, which the “likely” cancer cases are derived from is a dose response relationship for radiation exposure below what has been show with epidemiological studies to be dangerous. In other words, the LNT has no empirical support for its projections of low level does.

What about pregnant women? I’m a frequent flyer and get harrassed every time I refuse to go through the machine.

Mike, can you cite the studies you’re presumably using that shows regeneration from radiation damage?  Because last I checked, every dose was dangerous, no matter how small, and tiny doses spread out over time were cumulative.  Has the nature of ionizing radiation changed in the last few years when I wasn’t looking, perhaps?

But apart from that, there’s another issue not being addressed here, which is the lack of quantified security added by this invasion of privacy.  What plots have been stopped that would otherwise have succeeded?  What’s the actual benefit that results from the sacrifice in human rights?

By bickering over health concerns, we’re again ignoring that we’re being treated like “potential criminals” to protect against hijackings which can’t happen anymore by locking the cockpit door.  If this isn’t saving lives, why are we even considering the kind of scanner or its potential risks?

I don’t care if the scanners cured cancer. They do an inch-by-inch search of our bodies, contrary to the 4th amendment prohibition against searches of “persons” without a warrant.

Unlike metal detectors, which is a non-generalized search of your body and were implemented to detect a proven threat - that is, hijackings using metal guns at a rate of 4 a month on US flights back in the late 1960s and early 1970s, there has been no proven threat to even entertain constricting the 4th amendment.

Specifically, over the last HALF A CENTURY - that is 50 years - there have been Zero/Nada/Zilch fatalities from suicidal airline passengers with working non-metallic bombs on US flights. Even taking into account EVERY FLIGHT at ANYTIME and ANYWHERE IN THE WORLD, the two miserable failures of the “shoe bomber” and “underwear bomber” did not have working non-metallic bombs DESPITE the 5 YEARS to plan, test, refine, and develop working non-metallic bombs.

I conclude it must be tough to make something like that and to find an idiot willing to kill themselves. In fact, if it was so easy, since less than 50% of passengers are going through scanners, even this nearly non-existent threat leads to two questions. If this was truly a threat, which it isn’t statistically, why hasn’t something happened? If the scanners are so effective, why weren’t they 100% deployed - if they are SO NEEDED to save lives, why do we leave such a gaping hole in our ‘security’?

The answers are there is no frequent enough threat from suicidal airline passengers with working non-metallic bombs, and that they aren’t truly needed if less than 50% of passengers are subject to these “constitution-killing” wastes of time and money.

There is no reasonable threat to justify “administrative searches” which police cannot do. To draw an analogy, police cannot grope the groins of people without reasonable, articulable suspicion. We don’t even strip search or grope the sexual organs of people who visit prisoners DESPITE actual cases of prisoners receiving contraband.

Prisoners have better rights than US citizens. That is wrong.

For people who cannot live under the 4th amendment, all I can say is you don’t have to fly - the same thing I am told for wanting to live with my rights intact.

Of course, these same people will go shopping at a supermarket which has a higher, REAL DEATH RATE than the alleged suicidal airline passengers (with working non-metallic bombs) for which some seem so willing to surrender their rights based on a lesser risk than when one is shopping at a supermarket.

This is another thing that the government should not be doing. It is up to the airlines to make their planes safe for travel. It is not up to the taxpayers

Some studies report that an important distinction to be made is that backscatter devices concentrate radiation on the surface of the body, which apparently means the dosage, at the surface, is much higher than safety standards recommend.


@ John

Mike, can you cite the studies you’re presumably using that shows regeneration from radiation damage?

No problemo

Researchers with the U.S. Department of Energy (DOE)‘s Lawrence Berkeley National Laboratory (Berkeley Lab), through a combination of time-lapse live imaging and mathematical modeling of a special line of human breast cells, have found evidence to suggest that for low dose levels of ionizing radiation, cancer risks may not be directly proportional to dose. This contradicts the standard model for predicting biological damage from ionizing radiation - the linear-no-threshold hypothesis or LNT - which holds that risk is directly proportional to dose at all levels of irradiation. - PMCID: PMC3258602

Now can you cite epidemiological data supporting the LNT? Oh, that’s right, you can’t because none exists.

Because last I checked

You mean you personally have performed epidemiological studies validating the current accepted dose response relationship for low level ionizing radiation? Kudos to you sir.

Has the nature of ionizing radiation changed in the last few years when I wasn’t looking, perhaps?

Has the nature of low level ionizing radiation ever been accurately understood and modeled?

You beclown yourself.

@MIKE H. Clarification requested.

1) I believe you are saying that at “low enough doses”, there has been no correlation to cancer risk. So, for example, 1000 low threshold doses(defined by lower than ionizing radiation level, say, of 22Kev or so which I recall…or use the millimeter wave energies which under ionizing radiation energy levels..) have not been shown to be cumulative over time, vs 1 instance at 1000 times the threshold dose.

Contrasted with, I think we all agree, there are measurable risks for higher single dose exposures such as how they determine nuclear radiation exposure (although these are particles and not ‘waves’, the idea is to compare equivalent energy output…although you could argue they are different types of radiation as particles have mass…but let’s assume the energy levels are what is important for the moment).

2) Mike, if we assume Berkely Lab’s results, which is saying that for low levels the cancer risk is not proportional to dose, then that would imply even a low level dose could have a HIGHER than expected risk vs the LNT model prediction for a low dose?

Or, are you saying that Berkely Lab’s is showing cancer risks are LOWER for small doses than what the LNT model would predict on linear extrapolation?

My main question is that you are saying at low enough doses, the cancer risks on biological processes decrease to very low levels that are statistically insignificant vs the LNT model which says that the sum of low dose exposure becomes comparable to a single dose of accumulated exposure (or something like that).

We do have RNA enzymes I read recently that help replicating DNA “fix” errors in replication. So, maybe, the assertion is those processes are good enough to fight single low-level exposures.

The net/net is that you are assuming that 675 million exposures (passenger count on average in US flights) of low level (under ionizing radiation threshold by a fair amount) are statistically 0 risk vs using LNT to know we are causing 6 cancers a year, with maybe a mortality rate of 2 deaths, correct?

The only prudent thing is to listen to the International Atomic Energy Agency and the International Commission on Radiological Protection: “The ICRP recommends that any exposure above the natural background radiation should be kept as low as reasonably achievable.”  We can reasonably
throw body scanners that emit ionizing radiation in the trash can, and we should. 

We could also listen to the National Academy of Sciences:  “The committee has concluded that there is no compelling evidence to indicate a dose threshold below which the risk of tumor induction is zero.”  All ionizing radiation, at any dose, causes cancer.  Lower doses cause fewer cancers, but there is no safe dose.

Read more about this, including an explanation of why scientific studies to establish the danger of very low doses of radiation aren’t feasible, at:

“They say the risk is minimal, but statistically someone is going to get skin cancer from these X-rays,” Dr Michael Love, who runs an X-ray lab at the department of biophysics and biophysical chemistry at Johns Hopkins University school of medicine, told AFP.“No exposure to X-ray is considered beneficial. We know X-rays are hazardous but we have a situation at the airports where people are so eager to fly that they will risk their lives in this manner,”

Bill Fisher

Feb. 27, 2012, 9 p.m.

TSA has also avoided any discussion of the backscatter x-ray systems because of the lingering health and privacy problems and appears to attempting to mislead the public into believing that those also have these improvements. They continue to dodge Congressional demands for independent testing despite evidence that these will result in an additional 100 cancer deaths each year.

The x-ray systems also lack any privacy protection and a graphic naked image of each passenger is produced.

TSA could speed up airport screening if the scanners as a secondary screening device as originally intended. It takes 12 seconds per passenger to go through the scanner but only 2 seconds for the metal detector. This adds up when there are hundreds of people in line.

Almost all of the items found by TSA in 2011 were found using the x-ray belt and walk through metal detectors, not the scanners.
Germany abandoned them and went back to metal detectors because of the 54% false positive rate with MMW while failing to detect items 40% of the time. The scanners are only used on 30% of passengers, the rest are sent through metal detectors so these aren’t making anyone “safer” if only some passengers are scanned.

These also place an unfair burden on those with ostomy appliances, insulin pumps and women wearing sanitary products. These people will receive a full body pat down at minimum and may be subjected to a strip search like the three women at JFK airport.

There is also an implication of government corruption and deceit associated with the deployment of these systems which should be investigated by an independent special prosecutor.

@ Jeff P

1)  The risks of (relatively) high dose radiation are well known and there exists a large body of empirical that allows us to accurately quantify it.

Low doses, like those seen from the scanners are impossible to quantify because any epidemiological study would require such a large group over such a long observational time that you could not adequately control for it. With the kinds of doses we are talking about here, the LNT tells us we would see an additional handfull of cancer cases over 25 years in a population of 100,000. There is no way a study could be constructed to bear that out.

2) Based on the UCB’s findings, the authors conclude that extrapolating risk linearly from high dose as done with the LNT could lead to overestimation of cancer risk at low doses. They believe that low doses are effectively repaired by the body.

I do think that the X-ray body scanners are an unnecessary burdon to the flying public and thats a debate worth having, but Grabell is trying to argue that these scanners pose a health risk which by his own admission is small and that assertion simply cannot be justified.

As in most areas of government, companies receiving government contracts make a killing…of course including the manufacturer of the backscatter system, yet another technology for which “killing” is not too strong a term.

So, we have one “study,” that’s little more than a novel (i.e., “made up”) mathematical model that says what the authors wanted to see, and so the devices are safe.  Yeah, that’s totally better than all the radiation experts who say “unsafe at any level.”  Any scientist I’ve worked with pulling something like that would have been booted out of the lab by lunchtime.

But again, that’s not really the issue.  That’s just a diversion to avoid the real problems that (a) the machines don’t find anything useful and (b) it’s still a violation of this country’s foundational values.

It sounds like the occational traveler has nothing to worry about but what about all the airport security workers who have to stand beside the scanners all day operating them? Did the study examin this?

Well said Jeff P!!!! and Mike H.

None of this is answering my concerns:
1) Last year, there was a big bruhaha about mammograms actually causing breast cancer in women, and they should not even be given regularly to women younger than 50 years old.
2) Ionizing radiation, as we now understand it, is cumulative in the body.
3) Low dose may be better, however It is quite disturbing to learn that annual limits of radiation exposure even exist because it is cumulative over one’s lifetime, not for each year. We already get x-rays at doctor’s and dentists offices for valid medical reasons. Clearly this idiotic annual exposure limit did not come from any of the scientists that were interviewed.
The difference between focusing ionizing radiation directly on the skin vs. overall cosmic ray-type radiation one receives when up in a plane or at high altitudes may not be the same at all: the second is more generalized, therefore the prime defense of this x-ray technology sounds flawed or spurious.

Here’s a bit of backwards-implied logic to ponder:
Is it worth aiding frequent flyers in their development of cancer (there is no way to know exactly how much surface or skin radiation anyone has already been exposed to) for the sake of a handful of terrorists, especially when safer scanning technology already exists?

Ooops, nearly forgot to mention that I think I heard that mammograms emit somewhere between 300 to 400 times!! (not a typo) the level of radiation than a standard chest x-ray. Therefore women who already had numerous mammogram should be exposed to more.

I agree that these x-ray machines should be tossed in the trash. Realize this represents maybe 2 to 2.5 generations of women who have already been exposed to annual mammograms and therefore, way too much radiation.

What about those of us who have received intensive radiation when being treated for cancer and have been told that we could not again have any radiation treatment because of the dosage received? Even a small amount adds on to that.

Yes, absolutely! CAT scans, chest x-rays, radiation treatments, dental x-rays, mammograms, medical x-ray treatments are cumulative.
All heavily exposed patients plus frequent fliers need to opt out.

Who knows how many Americans may be involved.
What about foreigner visitors who do not speak the language well. Will they even know what potential hazard these machines pose?

Worse, there is no independent scientific discussion without data sharing, and this is not happening either. So forget any science behind it, this is politics as usual. Independent scientists have basically been shut out of this discussion.

US agencies have a history of aiding and abetting spectacular examples of junk science, including water flouridation, brominated vegetable oil, aspartame, and a host of pesticides that are killing bees.
Why not add a few more x-rays to this toxic brew?

Let’s look deeper: former Homeland Security Secretary Michael Chertoff is the man selling these scanners to the US government, as we’ve known for more than 2 years (thank you Harry Shearer).  Not to be paranoid much but I am not trustful of the technology based on the salesman/promoter alone.

A simple Web search of “michael chertoff airport scanners” reveals all . . . though it seems mostly by “left-leaning” publications. Oh well.  Opt-out & manual pat-down for me, please, Mr. TSA Man.

Can never take the TSA complaints seriously or expect corrections when there are men in power who think nothing of demanding that a state has the power to command a woman to have a vaginal probe inserted into her most private parts without her consent or the recommend of her physician, The indignity of the TSA pat down is no where near as humiliating as the STATE MANDATED VAGINAL PROBE.

Last time I flew out of Logan airport, I was delayed because my belt set off the alarm.  I was sent through the full body scanner before I could think to object.  While I was waiting for my belt to come through, I noticed that every woman behind me was sent through the full body scanner - and not one man.  I will never go through that scanner again.  I think they are invasive and after that experience, I think they are creepy.

The TSA is in for not completely informing anyone who has had major medical x-rays, women and children of possible dangers.
They do this by denying that any real risk exists!!
Then they come up with spurious excuses, like they need competition among technologies to keep costs down…It demonstrates very sad state of science education in the US. Frankly, the entire issue seems deceptive in nature, preying on the uninformed.

Readers may want to consider educating friends and family to opt out, so a growing number of air travelers use their feet to give the TSA a message.

@AESOP55. It is very suspicious if they only send one gender through. Here are some thoughts on the GeTSApo tactics.

If they only have woman assigned and available for grope downs on the 100% false positives from the scanners with no male clerks assigned, then they may choose women only.

When I opted out on last two business trips at a different airport, they was no gender bias. They run the strip search scanners 100% at the gates and allow metal detectors when the line gets backed up.

I guess you might say they “sacrifice security for convenience” if they allow metal detectors…because the strip search scanners are so necessary.

Are they safe? Ask a pilot. They can tell you all about them as they walk through the metal detector. Pilots, as “frequent fliers”, are not required to go through the scanners.

I always ask for a pat down, refusing the scanners. Airport officials don’t like it, but what do I care? Fortunately, I odn’t fly that often. It amazes me that the majority of the public believes they must go trhough the scanner.

I was subjected to both scanner and pat-down.  Has that happened to anyone else——-a false positive from the scanner?  After going through the scanner, I was told only that my whole body showed problems and I was subjected to a complete pat-down.

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