[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: eBay x-ray tubes & justified fears (fwd)



---------- Forwarded message ----------
Date: Sun, 12 Aug 2007 01:11:30 -0700
From: Frank <fxrays@xxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: eBay x-ray tubes & justified fears (fwd)

Tesla was reported  to X ray  his head for 1/2 per day for many 
years. He claimed it would calm and relax his mind.

I collect X ray machines and tubes, especially pre Coolidge ones and 
have a large number of books on the subject.
I have some of the first X ray tubes made to Coolidge to a shoe 
fitter X ray. My first shoe fitter machine I owned was when I 
was  about 15 and my first gas tube was when I was 16. The famous 
Crookes Maltese cross tube was the first X ray tube.
Using the early gas tubes, exposure times were up to 1/2hr! The power 
source was typically an induction coil or Tesla coil capable of 
putting out at least a 6" spark. A voltage equivalent to a 3" spark 
was typical for most X ray operations back then.

Although patients occasionally developed burns, it was very rare.
The operators of the machines was another story tho, they were 
exposed to hundreds of hours or radiation while the machines were 
operating and suffered terrible damage to their hands and many died 
from cancer. Edison's assistant was the first documented case of 
death by exposure due to X rays and was the reason Edison dropped 
anything to do with the manufacture of X ray tubes and systems.

The first X ray systems were not shielded. The tube was in the open 
air and generated a hemisphere of X rays with a cone of concentrated 
radiation in the center of the sphere..

As the Coolidge tube came on line, lower operating voltages and more 
intense X rays were the norm. Even the first Coolidge tubes were not shielded.
This tube, coupled with better and faster films reduced the exposure 
times from many minutes to typically seconds or fractions of seconds.

The person who had the CAT scan was injected with a short half life 
radioactive dye and that is why he clicked! Kind of a reverse X ray, 
the patient is the radioactive source and sensitive detectors, called 
scintillators, were moved over the body and a computer put the 
concentrated points of radiation together to made sense of the readings.

During the cold war era, the US published exposure rates that were 
shocking. They did not think anything of saying a person could be 
exposed to 500 REMS for a few hrs and not be harmed, even tho all 
their hair fell out, they vomited blood and had horrible burns. Yah, right!

The first color televisions actually produced mild X rays too and I 
am unaware of any repair man or viewer suffering from exposure.

The key to radiation damage is the intensity of the radiation, the 
time exposed and the TYPE or radiation.

I have scanned the area when operating these old tubes and machines 
to determine the actual amount of radiation being produced and I am 
more afraid of a modern X ray tube causing damage than a gas tube.
Of course I do not expose myself or stand in front of the tube, I 
ain't that stupid, but the over exaggeration and fear of X rays and 
radiation in general is vastly blown out of proportion!
A radium dial wrist watch will expose the wearer to more radiation 
during their lifetime than all the X rays they would ever have.

Now, high power X ray machines using voltages in excess of 75 KV, are 
used for actual therapy and can do significant damage  if not 
operated properly. Even then, the Coolidge type tube is a well 
refined and focused tube compared to a gas one and are truly 
dangerous if being placed directly in front of the beam but outside 
that, they are safe for exposure, especially if one is directly 
behind the target.
Persons treated by these machines will have burns and damage to the 
treated area, that is what the tube was designed to do.

The biggest risk of operating a unshielded tube is the extreme high 
voltage present at the terminals. This can kill!

Like anything else, individual tolerances pay a big factor with 
radiation and children are at a higher risk for harm than an adult.

So, collect X ray tubes, sure, operate them, absolutely not unless 
you understand the risks, especially at higher voltages and exposed tubes.
Understand radiation exposure is  cumulative, the more you play, the 
more you pay! Implosion of the tube or shock hazards are the 2 biggest dangers!

Frank

At 09:38 AM 8/5/2007 -0600, you wrote:

>---------- Forwarded message ----------
>Date: Sun, 05 Aug 2007 11:14:07 -0400
>From: Dave Pierson <davep@xxxxxxxx>
>To: Tesla list <tesla@xxxxxxxxxx>
>Subject: Re: eBay x-ray tubes & justified fears (fwd)
>
>
> >> If you think the word idiot is too strong, please consider the fact this
> >> moron was attempting to run a 120 kV X-ray tube out in the open air with
> >> virtually no shielding of any type.
>
> >Um...  In hospitals they aim those at people.  They did it to me, yet I'm
> >still alive.
>    You were tended to, and treatment guided by, skilled professionals.
>    There have been instances, thru technical failure and lack of
>    knowledge, where people have been seriously killed.
>
>    Suggest talking to the radiologist about the precautions they
>    take.  Suggest noting that when, eg, dental xrays are taken
>    technician staands away, and behind shielded wall.
>
>    Those machines have lotsa shielding to control where the beam goes.
>    Tube in open air means main beam and strays go anywhere.
>
> >High-voltage hobbyists will notice many tempting x-ray tubes being
> >constantly listed on eBay.  I'd always assumed that they were lethal.
> >But I've recently been wondering about the genuine danger of common
> >sources of ionizing radiation, versus the hysterical overreaction typical
> >of Americans.  Ra-dee-ation!  "Any risk is too much risk?"  Yeah, right.
> >But specifically, if the radiation burns weren't an issue, perhaps the
> >cancer risk isn't as high as I've always imagined.  How much of our
> >opinion of x-ray tubes is based on reality?
>     How much of beliefs in safety is based on the fact that low doses are
>     cumulative, show up effects later.  Yes 'some' risks are overstated.
>     SOME ARE REAL.  Suggest calm discussion with  professional radiologist.
>
> >For example, if you stand outside in unshielded sunlight for a couple of
> >hours, you receive a serious radiation burn, with skin peeling and falling
> >off.  Yet the cancer risk is quite small, and people in tropical countries
> >even ignore the problem entirely.  The effect might be mostly limited to
> >the outer 1mm layers.
>    But make no mistake, it's a genuine radiation burn.
>    and, repeated over time gives cancer.  Operative word is _repeated_:
>    tropical residents get browned, once and then more or less protected.
>    temperate residents, who burn REPEATEDLY (if incautious) get cumulative
>    damage,  later elevated cncer levels.
>
> >If you take a geiger counter along on a cross-country airline flight, be
> >prepared for a surprise.  It starts clicking within seconds of takeoff.
> >At cruising altitude it roars: ten or twenty counts per second ( and
> >supposedly much higher during solar flares.)  But we aren't terrified of
> >air travel because of this.  Should we be?
>    Please quantify '20 counts per minute' to rems, then to observable,
>tested
>    effects levels.  Hint: 20 counts per minute is Way Below the high
>    risk levels.  Hint II: there are data showing higher cancer levels amongst
>    really frequent flyers, last i looked.  Haven't got a cite.
>
> >If you look up the ratings for modern dental x-ray equipment, and
> >calculate the exposure needed for the mildest of x-ray burns, guess what
> >the exposure time is.  Seven thousand hours.  You'll heal too fast. You
> >can't get an x-ray burn from a dental unit; increased cancer risk is the
> >only danger, and it's the dental techs using the equipment every day who
> >should worry.  (And how does the risk compare with other real-world
> >acceptable risks, such as cancer from peanut butter, or the risk from
> >solar UV in outdoor employment?)
>
> >The USA is weird about x-ray tubes, but I'm starting to get skeptical
> >about the justification.  At the science museum in Paris, "Palais de
> >Decouvertes," there's an exhibit case with an unshielded Crookes-era x-ray
> >tube, a fluorescent plate, and a sample object.  Press the button, and you
> >see the green glowing image; bright enough that it's easily seen in a well
> >lit museum. The tube is behind the fluorescent plate, so the x-rays are
> >aimed at your face!  Maybe the cancer risk ridiculously insignificant.
> >Or is that museum exhibit a clear danger to the public?
>     It might be.
>
> >So here's the important questions:
>
> >  If intensity is below the threshold for x-ray burns, then what is
> >  the cancer risk from common x-ray sources?  Specifically, how does it
> >  compare with cancer risk of ionizing radiation which EASILY causes
> >  radiation burns: the risk of going outside in the sun?  Or how dangerous
> >  is an x-ray tube when compared with the risk of working outdoors, or of
> >  living in a tropical country and getting huge amounts of hard UV
> >  exposure every day?
>    Not clear to me that comparing UV (sunlight) to X Ray is apropos.
>    Suggest that comparing 'energy' across UV vs XRay exposure is iffy.
>    (yes: the two specta merge one to the other...)
>
> >  Also:  intensity being equal, (or if accumulated exposure is equal,) how
> >  much worse are x-ray frequencies when compared with solar UV?  I
> >  realize that UV produces surface cancers which are easily noticed,
> >  while x-rays cause hidden damage deep inside.  But ignoring that fear,
> >  how much worse for cancer risk is a dental x-ray tube when compared
> >  with a very dim UV sunlamp which cannot produce a sunburn?  Tens of
> >  times worse?  Thousands?  Or much less?  In other words, is our fear of
> >  low-power x-ray tubes justified?
>    Suggest calm discussion with professional radiologist.
>    Also what is 'low power' xray?  120KV?
>
> >And finally:
>
> >Just this year a research group discovered that x-ray cancer is not equal
> >for all humans.  The risk depends on genetics.  (This is contrary to what
> >everyone has always assumed.)  In a study of patients exposed to a dose of
> >head x-rays in the 1950s, the incidence of cancer was concentrated in
> >certain families.  Note that this was a major dose, one intended to kill
> >ringworm infections, and which caused hair to fall out.  People from
> >certain families got brain cancer.
> >
> >  http://www.sciencenews.org/articles/20070519/toc.asp
> >  http://www.bioone.org/perlserv/?request=get-document&doi=10.1667%2FRR3329
>
> >This resembles the "moon children" problem, xeroderma pigmentosa, where
> >certain people who lack a DNA repair molecule will immediately acquire
> >skin cancer if they ever go outdoors in the sun.
>
> >Odd thought: perhaps humans are immune to x-rays, but people with a
> >certain genetic defect cannot tolerate even a small exposure, and this
> >population has biased our stats.
>    and thus are not human?
>
> >Odder thought: for Hiroshima-scale radiation exposure, I wonder if some
> >rare people never aquired radiation sickness.  Imagine if some "human
> >cockroaches" exist who would easily survive a nuke war.
>     I trust i may be pardoned for not volunteering myself, my family, nor
>     my neighbours (accidentally) as someone (HYPOTHETICALLY!) experiments
>     with such research?
>
>     And cockroach genetics are different than human: simpler.
>
>     Analogy:
>      I assist at professional pyrotechnic displays.
>      'some' folk get hurt at thi, every year, many because they think/say:
>       'O that rule isn't important'.
>
>      I have (small) time in licensed manufacturing operations.  One
>      occaisionally encoutners the attitude:
>        I don't think 'this mix' is all that sensitive.
>      Such people lose fingers, hands, lives, etc.
>
>      best
>       dwp