Basic summary: the radiation exposure from these newish full-body x-ray scanners is small, and really nothing to be worried about.  Nekkid pix and/or TSA groping is a different issue.

Here's a really fabulous discussion from twitter about the TSA's new backscatter x-ray full-body imaging systems, and the radiation risks from the delivered dose, captured 11/17/2010, about noon PST, roughly 2-3hrs after the conversation occurred.  I've curated it here to make it a bit more readable, and have maybe cleaned up a typo or two.

Here's the BadAstronomer post that I saw.

PhysicistLisa's "rant" starts here: http://is.gd/hi8Ic

 

@PhysicistLisa Lisa M

Ok friends it's rant time though I prefer think of it as educating with numbers.

If you believe that the new TSA policies are necessarily invasive,  please don't weaken  your case by spouting off about radiation dose

Making easily falsifiable statements will hurt your case, particularly if this goes to court. It is a lie that the doses are "unknown"

Prominent experts in the field of radiation science HAVE done dose calculations of these scanners and estimate them at .005-.009 mrem

Now let's just say... just say for the sake of conservatism (what I do at my job every day) that this is off by an order of magnitude

So we pick the highest estimate and mark it off by 1 order of magnitude, at 0.09 mrem...

By moving from Atlanta to Colorado,  I upped my annual dose by 52 mrem per year. because there is more uranium in the soil here and more cosmic radiation dose as I am at a higher elevation.

This means that I would have to stand in that scanner 578 x's to make up the difference in radiation dose between 1 yr in CO vs. [1 yr in] GA

and that's making an assumption of an order of magnitude error by people who are absolute experts in the area of dose calculation

If you think that the privacy concerns should be fought, you are potentially harming the eventual court case by allowing emotionally charged non-science to be considered at all on the agenda. Please consider standing out against this. it will help your case in the long run.

 Making any one part of an argument look foolish when faced with facts will make people think about how much they believe the rest of it.

PhysicistLisa Lisa M

A few people have brought this article to my attention http://gizmodo.com/5692198/ @mik3cap @popsciguy

I stand by the numbers i have stated and also by the statement that the doses calced by *outside groups* DO consider the dose is to the skin

normalizing the dose calc to a whole body dose is a common practice for compliance with fed regs, however there are regs for organ dose too

If you read the letter of concern note that there is no actual numbers presented for the extra risks discussed.

as a professional, i do not trust sources that discuss "dangers" with no numbers or calculations associated with them.

and i think that reading his addendums to the article at the bottom really says a lot.

Though imo saying the "cancer risks are not well understood"is a lot like saying "the effects of vaccines on autism are not well understood"

FYI, i hadn't read that article before because i broke up with Gizmodo a while ago for their tendency to not present the fact

PhysicistLisa Lisa M

and honestly... i thought about putting it all in a blog post and i still might, but if i link a blog you're a lot less likely to read it :)

-----

@bird2brain John McKee

@PhysicistLisa How does the scan compare with the subsequent flight? Also, Aren't there two types of scanners? THANKS!

PhysicistLisa Lisa M

.@bird2brain the estimate of 6 hours flight is generally accepted to be 2 mrem, so the dose from the scanner is much less than the flight

.@bird2brain yes, millimeter wave scanners are non-ionizing (like cell phone or MRI) & backscatter rad are ionizing (like an x-ray or CT)

.@bird2brain 2 different kinds of rad with two completely different sets of potential and theoretical health effects

 ----

Physicsguru Curtis Meisenheimer

@PhysicistLisa Isn't the issue more of the type of radiation, ie X-ray vice gamma. Therefore, the dose is absorbed locally in the skin...

@PhysicistLisa as opposed to whole body radiation exposure?

PhysicistLisa Lisa M

.@Physicsguru x-ray and gamma are both e-mag ionizing radiation, just x are emitted by electrons and gamma is emitted by the nucleus

.@Physicsguru dose calculated to the skin or any other organ is normalized to a whole body equivalent for compliance with regulation

.@Physicsguru the fact that this is a skin dose *has* been considered.

 ----

GeekStuffOG Matt Cipoletti

@PhysicistLisa just to be clear we are saying that the radiation portion of the argument is hulaballoo but the privacy issues are legit?

PhysicistLisa Lisa M

@GeekStuffOG yes. that is what i'm saying. i just hate seeing a legitimate argument being marred by bad science

 ----

jduvel Jason Duvel

@PhysicistLisa ...what about pilots who may be scanned multiple times per day depending on their flights, and for many years? ...

PhysicistLisa Lisa M

.@jduvel well you saw my numbers... compared to their flights the scanners are not really a concern for pilots. It's an increasing trend to badge pilots (give them an external radiation dose monitor) so they know the dose they are getting in a year.

 ----

PhoinixArt Phoinix

@PhysicistLisa Question: Would there be added risk associated with air-crew continually using them? Adding onto their doses from flying etc?

PhysicistLisa Lisa M

@PhoinixArt compared to the dose they get from the flight itself, it would take a long time for it to add up to a couple extra flights

 ----

thefoodgeek Brian J. Geiger

@PhysicistLisa So the argument about the radiation being absorbed into a small percentage of the body volume is likewise irrelevant?

PhysicistLisa Lisa M

.@thefoodgeek it's not irrelevant, it's accounted for in the dose calculations that have been done, despite what the media has told you

 ----

GlennF Glenn Fleishman

@stradling @PhysicistLisa It’s not that I dispute the science. I dispute the veracity of the scanner makers. Dose calcs ≠ clinical msrments

PhysicistLisa Lisa M

@GlennF i'm not basing my numbers off of the scanner makers my numbers are from outside groups like the Health Physics Society @stradling

@GlennF and the experiments that have been done so far show doses less than calculated.

 ----

bird2brain John McKee

@PhysicistLisa But the backscatter is still not much of a concern?

PhysicistLisa Lisa M

@bird2brain in my professional opinion? no i would not worry about the dose from backscatter radiation.

 ----

jduvel Jason Duvel

@PhysicistLisa Though even using your order of magnitude # with 4 scans a day and 200 days of flying comes up to 72 mrem/year.

PhysicistLisa Lisa M

@jduvel which is lower than the dose to the public of 100 mrem/yr enforced by 10CFR20. Radiation workers are allowed a higher dose even

 ----

popthestack Ryan Martinsen

@PhysicistLisa can you post your sources for the studies you've read?

PhysicistLisa Lisa M

@popthestack http://www.public.asu.edu/~atppr/RPD-Final-Form.pdf

 ----

PhysicistLisa Lisa M

@particle_person i don't think that there's any credible calculations that would say this technology will cause a few extra deaths a year

@particle_person but your point is an interesting philosophical one. i don't know enough about terrorists risk rates to say for sure

 

markbeadles Mark Beadles

@PhysicistLisa Agreed about individual radiation risk, but is aggregate radiation risk > aggregate terror risk?

PhysicistLisa Lisa M

@markbeadles i don't know enough about aggregate terror risk to comment for sure but anyone who's telling you that the scanners are going to kill multiple people a year are not using defensible calculation technique

 ----

Physicsguru Curtis Meisenheimer

@PhysicistLisa Understandable. Isn't mm-wave superior since it isn't ionizing? Or do they lose resolution?

PhysicistLisa Lisa M

@Physicsguru i'm not entirely sure. over all there is no proven risk to low levels of non-ionizing so safer, in essence yes.

 ----

treelobsters Tree Lobsters!

@PhysicistLisa How much extra radiation exposure does someone get from flying at 30000 feet? i.e. is it more or less than the scanner

PhysicistLisa Lisa M

@treelobsters 2 mrem for a 6 hour flight. much more

 ----

GeekStuffOG Matt Cipoletti

@PhysicistLisa anyopinion on safety for pregnant women?

PhysicistLisa Lisa M

@GeekStuffOG your dose would be much higher on the plane ride itself. read here http://www.ncbi.nlm.nih.gov/pmc/articles/PMC153688/

@GeekStuffOG that addresses the us and canada's stance on flying during pregnancy.

@GeekStuffOG the fact of the matter is that it is mostly skin dose and the baby isn't actually that close to the surface

 ----

Finguz Paul Finlay

@PhysicistLisa So "I don't like the invasion of privacy and the fewer mrems the better, no matter how small the dose" isn't unreasonable? :)

PhysicistLisa Lisa M

@Finguz i think that worrying about .009 mrem is a little unreasonable honestly. The things you do in a day that alter you by .009 mrem...

@Finguz i completely stand by the right to privacy though. i just worry people will weaken their court case when they are inevitably made to look foolish on the stand if they start to bring up the rad dose...

 ----

GlennF Glenn Fleishman

@PhysicistLisa @stradling Experiments by whom? Who provided #s used for calculations? My assumption starts with notion that scanner...

PhysicistLisa Lisa M

@GlennF the ones i have been able to actually read the full calculations by are by Arizona State University and the Health Physics Society

 [there's actually a quite a bit of dialogue between @GlennF and @PhysicistLisa - I encourage you to check it out]

A friend of mine - well, actually, she's one of the bartenders at the neighborhood watering hole - has just launched a quarterly, Whore! Magazine.  On their facebook page, the question was posed: What is feminism?

One basic principle came to mind, something I'd in the past always used as a quick definition of what feminism means to me: Equal pay for equal work.

But this isn't enough, is it?  In many ways, this idea of equal pay for equal work follows from the economic shifts during WW2, when women entered the job force to fill the roles that were held by men, now fighting overseas.  It was somewhat of a novelty, and compensation was not at the level of men's compensation, but it was essential for the war effort.   After the war and after the GIs returned, having tasted financial independence, many women couldn't go back to their previous role as housewives.

But there's more to feminism - where is the suffrage, for example.  What about sexuality?  What about other aspects of gender dynamics I eventually threw this together - it's what I think feminism is, or what I think it should be, today.  It's a little sloppy, but I like it.  Maybe I'll clean it up at some point.

feminism is a clear path to the top rung of the ladder
feminism is walking down the street in the middle of the night with nary a concern
feminism is being able to make your own decisions about your body
feminism is equal compensation for equal merit
feminism is making sure the doors are open for all
feminism still has a ways to go

Amanda Recupido, who I know through twitter (and we have common friends, it turns out) has a blog This Is What A Feminist Looks Like.  The blog shows pictures of women living their lives.  There is not "feminist" look - these are pictures of women from all walks of life, doing all sorts of different things.  This made me think of one woman in particular: Jenny Hodgers.

I hadn't made this connection previously, but I've always thought of war as chaos, unleashing all sorts of unpredictable energies that can completely transform a society, not least of which, it can shatter it, if you're on the losing side.  And WWII seemed to have improved the lot of American women economically, and as a consequence, socially.  Here's a public radio piece about a woman who fought in the US Civil War, and she was transformed because of it:  In Civil War, Woman Fought For Freedom Like A Man

Albert Cashier, right.

Her name was Jennie Hodgers; her nom de guerre was Albert Cashier.

Here's an excerpt from the piece, but I encourage you to give it a listen.

LINDA PAUL: To get an idea why Jennie Hodgers may have subjected herself to the rigors of war, you need to know a little about the U.S. job market in 1861.

Ms. DEANNE BLANTON (Co-Author, "They Fought Like Demons: Women Soldiers in the Civil War"): Well, a private in the Union Army made $13 a month, which was easily double what a woman would make as a laundress, or a seamstress or even a maid.
[...]
Ms. BLANTON: But once they were in the pants and earning more money and spending their money, they seemed to greatly enjoy the freedom that came with being perceived as a man.

PAUL: Women at the time of the Civil War couldn't vote. They mostly depended on men to survive. In return, they were supposed to devote their time and talents entirely to husbands, children and their extended families. That was the Victorian ideal...that was mostly aimed at middle and upper-class women, and they're not the ones who went off to war.


Ms. BLANTON: The women who went to war, who disguised themselves as men and carried a gun, were overwhelmingly working-class women, immigrant women, poor women, urban women and yeoman farm girls.


PAUL: Jennie Hodgers part of this group. She was an immigrant from Clogherhead, Ireland, who couldn't read or write. By the end of the war, she needed to make some tough decisions about her identity. If she stayed Albert Cashier, it was more likely she'd find work, keep the friends she made during the war and be part of a respected community of Civil War veterans.


Ms. BLANTON: She can have a bank account. She can vote in elections - and she did, by the way. Or, if she goes back and puts on a dress and tells everyone that she's Jennie, she has just lost her entire life.

PAUL: Jennie's decision: to continue her life as a man.

The radio piece goes on to describe what happens to Albert/Jennie:

PAUL: It's not Jennie Hodgers' name that's read on Memorial Day because it's Albert the town remembers. And it wasn't Jennie, the doctor sent to an insane asylum at the end of her life, it was Albert's name on the commitment papers.


PAUL: Here's what happened: late in her life, Jennie Hodgers was still living undetected as Albert Cashier in Saunemin, but at age 67, when she was hit by a car, she was sent to live at a soldiers' and sailors' home for disabled war vets. A couple of people there knew her secret, but remarkably, it was a few years before it slipped out and made it into newspapers around the country. That's when the Pension Bureau launched its fraud investigation.

At about the same time, Cashier had become confused and noisy. Her condition was what today we'd probably call dementia. But back then, as was typical, she was deemed insane and dispatched to an asylum. The identity she had chosen was ignored, or as they may have seen it, corrected. She was placed in the women's ward and forced to wear skirts.

Ms. O'DONNELL: It was so devastating to her that she would take pins and pin the skirt together between the legs to make them look like pants. And when she did that, they were very awkward 'cause they were so baggy, and she fell. And the fall resulted in an infection, and she never ever recovered from the infection. That was the cause of the death.

PAUL: In the end, Jennie Hodgers did get rid of that dreaded cumbersome skirt. Albert Cashier's comrades made sure that she was buried in her soldier's uniform.  And that she received a proper military funeral.

New York City Thoughts

I've been thinking about New York City and the 9/11/2001 attacks on the WTC and the Pentagon nine years ago.  Here is a holiday card that was sent out that year by the Park Slope Gallery.  

Today, nine years later, because of these attacks, we are enmeshed in two wars in the Middle East, with blood directly spilled in Iraq, Afghanistan, Pakistan.  Our country is deeply divided over the conduct and execution of the war on our part.  In addition to the 3000+ lives lost in America that horrible day, we've lost nearly 5,500 US military lives not to mention an additional 1,000 coalition military lives as well as about 10,000 lives from the Iraqi security forces and almost 48,000 Iraqi civilian lives since 2005 (with low-bound estimates of about 22,000 reported Iraqi deaths for 2003 and 2004 including the invasion phase and higher civilian casualty estimates of about 425,000 to 800,000 for the period of March 2003 to June 2006).  In Afghanistan from 2001 to 2009, estimates are around 10,000 to 13,000 civilian lives lost and around 4,000 to 5,000 Afghan police and military lives lost.  And I am not even going into the numbers of people wounded but not killed.

The image from this peace rally in NYC's Union Square after the 9/11 attacks was taken and assembled by gallery director Phyllis Wrynn.  I am often moved, sometimes to the brink of tears, by the power of the image, the power of its timeless message.  Within a week of the tragedy and horror that gripped the city, our nation, and for a time, the world, somehow citizens of New York City came together amidst the roiling raw emotions of the time to call for not blood nor revenge, but for peace and justice.  I've thought of this image and Gandhi's quotation so many many times over the years since the attacks - so powerful, so important, and yet so easily forgotten, much to the peril of all of us who seek to make our world a better place.

My great thanks to Phyllis and The Park Slope Gallery for helping to dig up a copy of the original card for me several months ago!  And also: bonus image from NYC photographer George Forss.  Check out his Landmark Photos in the Park Slope Gallery store.

[ If I may indulge in a wee bit of intellectual masturbation:

The numbers represent a hell of a lot of blood from war deaths- if you assume 4.5 liters of blood in an adult, that would be over 120,000 gallons of blood (based on the low end of the number of deaths, and this doesn't count those who are wounded and do not die).  

The standard oil barrel is 42 gallons, so we're talking about 11,000 barrels of blood so far from these two wars minimum. Interesting fact: the estimated oil consumption for the US, EU and China combined is about 42 million barrels PER DAY.

This is a bullshit comparison, of course, I mean, how many natural deaths occur, and what's that blood volume?  Or volume of urine produced per day.  Etc etc etc.  Also, a huge problem with thinking of the Afghan war in terms of blood-for-oil is that Afghanistan itself doesn't have much in the way of petroleum fields.  On the other hand, one can (and I do) argue that much of the money that is/was funding al Qaeda at the time of the 9/11 attacks had its source in Saudi oil profits, as well as the wealth of the bin Laden family and its various industries, such as construction engineering. ]

OK, it seems like a manufactured red-letter day, but in collaboration with and respect for my feminist collaborators, I'm honoring Marie Skłodowska Curie today, for International Women's Day.

She was the first woman to win a Nobel Prize (Physics, 1903, w/ advisor Henri Becquerel and fellow student Pierre Curie). She was the first person to win two Nobel Prizes in two different subjects (Physics 1903, Chemistry 1911). The work of her and her family on radioactivity and nuclear chemistry and physics has had a tremendous influence on modern physics, chemistry, biology.

With respect to society, she was the first woman to serve on the faculty of the University of Paris. As a woman, she faced considerable discrimination from her male peers, and it wasn't until her husband's tragic death that she truly emerged from his shadow and became the first woman professor at the University of Paris / Sorbonne. Despite her second Nobel Prize, the French Academy of Sciences (barely) failed to elect her into its membership in 1911 (her student became the first woman member in 1962). The revelation of her affair with physicist Paul Langevin was fuel for her rivals in academia, helped spur xenophobic (she was Polish, though working for France) and anti-Semitic rumors against her (she was not actually Jewish, though apparently even the anti-Semitic bigots that would fuel the Dreyfus affair wanted a piece of her).

She founded the Radium Institute (now the Maria Skłodowska–Curie Institute of Oncology) in Warsaw in the early 30's, while actively continuing her research in radioactivity at the Sorbonne to the very end. Sadly, it was that very subject matter that ultimately killed her by way of aplastic anemia, from exposure to the very radioactivity and substances that she discovered.

She has been described as an early feminist: emancipated and independent. And, it was said of her by Einstein, "Marie Curie is, of all celebrated beings, the only one whom fame has not corrupted."

Life is not easy for any of us. But what of that? We must have
perseverance and above all confidence in ourselves. We must believe
that we are gifted for something and that this thing must be attained. -- Marie Skłodowska Curie

Love
by Kathleen Fisher

The heartshape,

it turns out, is based
not upon the heart, but
the vulva. The heart,
it turns out,
more closely
resembles
the fist.

(from the literary journal Exquisite Corpse, No. 45, 1994)

A Difference Between Men and Women

I was hanging out at my local watering hole, the Lone Palm, the other night, and started talking to a young woman named Bethany.

She was drinking a glass of water - it was late, and wisely, she had switched over from the spirited drink to the hydrating drink in anticipation of the morning after the night before. She asked what I was drinking.

"It's a French martini." She stared at me, the martini glass, and at me again. "What's a French martini?" she asked, with a hint of dubiousness in her voice. "It's a classic drink actually - pineapple juice, Chambord, vodka. Maybe a hint of lemon." Perhaps appreciating the combination, she then asked, "Well, you know what they say about martinis, right?" Quizzickly, I said, "No, actually, what do they say about martinis?" At this point, her friend, a tall red-haired gentleman with a neatly trimmed beard and haircut had wandered over. "Well," Bethany continued, "One is not enought, and three are two many." I laughed, as did her friend.

"But," I pointed out, "you realize that you're trying to tell this to me, a guy. I think I can appreciate a third breast, maybe even a fourth." Her face twitched subtlely, as if she had just stopped her eyes from rolling up. She turned to her friend, "well, what do you think about martinis being like breasts." He thought for a moment, "Three breasts - I can work with that." This time Bethany's eyes DID roll. "OK, I get it. This saying doesn't work for guys."

I was surprised to discover that this saying about the martini has been attributed to Herb Caen, the late San Francisco Chronicle columnist... though frankly, I'm surprised that the saying isn't as old as, say, vermouth. Curiously, this also brought to mind the French idea that the perfect breast will fit into a champagne coupe - supposedly the coupe was modelled after the breasts of Marie Antoinette, and the dance troupe Folies Bergere used such a comparison for choosing their dancers.

Art Opening Reception for José Arenas, Philip Hua and.... Marta!

The other evening, I attended a first-Thursday reception for American Pastiche: Choose Your Own Adventure - Jose Arenas | Phillip Hua at Hang Art Gallery in San Francisco. Jose is one of my fantastic art teachers at Foothill College, and I rather like his work. The exhibition web site is here.

Amid the hustle and bustle, the schmoozing and networking, I happened to notice these two girls, completely absorbed in the creative process, perhaps inspired by everything going on around them, perhaps indifferent to it all.

I was captivated by their focus and dedication to their drawing. There's something pure about childish exploration.Many kids possess a single-mindedness and dexterity of engagement that many of us lose as we mature into adults. This is why it's often said that children make the best scientists, and why their artwork contains an élan that is elusive to many adults.

I was not the only one to notice this. The woman talking to these exciting new artists runs the Hang gallery (DJ Harmon, I believe). Well, she has a keen eye for emerging talent, and it made perfect sense to introduce the San Francisco art scene to the works of these two young ladies during this First Thursday event.

The drawing that's going up, is labelled "Marta, age 4 1/2. (NFS)." The collection of this evening's output from these two exciting new artists can be found here and also here and here