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High tension power lines and X-rays
I pulled this one off sci.med.radiology and am sending it FYI.
I hope to see some of us post our experiences on instrumentation
and EM interference; remember flourescent lights lighting under
these lines?
Jeff
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Jeffrey Leavey certhp@vnet.ibm.com
X-ray Lithography Program IBM Corp.
914-892-4595 East Fishkill, NY 12533
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Subject: power line corona causing X-ray?
From: labriola@ix.netcom.com (Donald Labriola)
Organization: Netcom
Newsgroups: sci.med,sci.med.radiology,sci.energy
Date*: Wed, 11 Jan 95 23:37:23 EST
I have been following the various studies on the correlation of power
line proximity and cancers for several years. What has been missing is
the nature of the causative agent. I believe that I may have located at
least one of the methods of effect.
I pass a series of high tension power lines while driving to work. I
have noticed the variation in corona noise generated by different poles
and in different weather... the thought came that the corona could
possibly be capable of generating soft X-radiation. Curosity led to a
series of experiments utilizing several different radiation sensing
methods.
The first test involved CaSO4 :Dy Thermoluminescent Dosimetry capsules
from the Radiation Detection Company in Sunnyvale, California. As I
understand it -- probably simplified -- this material acquires
dislocations in the crystal structure as the gamma particles pass
through. When gently heated, the crystal dislocations rebound and give
off photons which may be counted to give an estimation of the radiation
to which the detecter was subjected since last annealed. These detectors
are normally shielded to hide their responsitivity low energy gamma
(X-rays), but were obtained individually without shields.
In the experiment they were shielded from ultra violet light by an
opaque plastic. A group of twenty freshly annealed capsules were placed
at various sites near and away from power poles of various voltages.
The detectors were exposed for approximately one month and returned to
the company for readout. All of the detectors save one were very close
in value (mean=16.7, variance = 1.015, milliroentgens based on exposure
of controls to 60Co.); the remaining detector had a reading of 23: this
was 6.2 standard variations above the mean! This placed the reading of
the particular power tower 37% above the background.
The unusual tower is a 500kV (guess) / 6 wire power tower that
transverses San Dimas and LaVerne in the proximity of Foothill
Boulevard. It was also a copious producer of radio frequency
interference (RFI), able to overpower even strong AM radio stations
when the receiver was within a block of the tower.
This was interesting, but I wanted second test to verify the results.
This time a pair of Geiger counters were utilized. One was equipped with
a low energy gamma scintillator (Ludium Model 3 with detector model
44-3), the second was a hard particle detector (Ludium Model 3 with
detector model 44-7). The hard particle detector was used to verify that
the results were not skewed due to the presence of natural radioactive
rock (the tower was in what had once been riverbed). No measurable
differences were noted between the reference area readings and the site
of interest when using the hard detector. The low energy gamma detector
told quite a different story. Away from the high tension lines revealed
a reading of 150 to 250 cpm (counts per minute); under the power tower
gave a reading of approximately 500cpm on a dry day and 600 on a foggy
morning. The readings decreased as I proceeded from beneath the pole to
approximately 1/2 block away. The corona produced a very significant
audible crackling on the foggy morning.
The other locations that showed no significant variations from the
background levels on dry days. A couple showed increases of 50 to 100%
on foggy mornings.
A third measurement of the site in question was made using a Bicron
MicroRem LE with a solid state tissue equivalent ion chamber. It was
made on dry day; the time averaged reading at the site was approximately
30% higher that at a reference location approximately 2 blocks away
(~7.75 microRem/Hr vs. ~6 microRem/Hr).
The differences in the results would be expected if the energy were
skewed to the soft end of the X-ray scale --- the Ludium counter has a
greater sensitivity at low energy than the Bicron. This would be
expected as a greater number of free electrons in the air would be able
to attaing lower velocities than would attain the higher energy states
(the further it travels, the better chance of running into an air
molecule and giving up most of the energy).
These results, if verified, could show a measurable link between the
presence of high tension power lines and some of the reported health
effects. The spotty nature of which poles have corona problems and which
do not could also explain statistics which have the various cases
located near power lines, but not everyone near a power line having
problems. It could also explain the 4x higher rate of breast cancer
among male power line workers than the background level (usually below
the power lines with the upper torso exposed).
I would be very interested in finding others with the appropriate
equipment to verify my initial experiments, or with the knowledge to
point me to appropriate tests.
Sincerely,
Donald Labriola II, P.E. (labriola@ix.netcom.com)
Disclaimer: The tests were done to the best of my ability, but my
background and training are 17 years of biomedical instrumentation
electronics and an MSEE, with nothing formal in radiology or high energy
physics.
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Subject: Re: power line corona causing X-ray?
From: frank@rover.uchicago.edu (Frank R. Borger)
Organization: Radiation Therapy, Michael Reese Hospital
Newsgroups: sci.med,sci.med.radiology,sci.energy
Date*: Thu, 12 Jan 95 17:15:29 EST
In article <3f2bm4$sub@ixnews2.ix.netcom.com> labriola@ix.netcom.com (Donald Labriola) writes:
>The first test involved CaSO4 :Dy Thermoluminescent Dosimetry capsules
>...
>In the experiment they were shielded from ultra violet light by an
>opaque plastic. A group of twenty freshly annealed capsules were placed
>at various sites near and away from power poles of various voltages.
>The detectors were exposed for approximately one month and returned to
>the company for readout. All of the detectors save one were very close
>in value (mean=16.7, variance = 1.015, milliroentgens based on exposure
>of controls to 60Co.); the remaining detector had a reading of 23: this
>was 6.2 standard variations above the mean! This placed the reading of
>the particular power tower 37% above the background.
First suggestion: obtain some good introductory books about
statistics. Then repeat your measurements. In general, it is
quite normal to find one TLD capsul suddenly go bonkers out of
a sample of 20.
>These results, if verified, could show a measurable link between the
>presence of high tension power lines and some of the reported health
>effects. The spotty nature of which poles have corona problems and which
>do not could also explain statistics which have the various cases
>located near power lines, but not everyone near a power line having
>problems. It could also explain the 4x higher rate of breast cancer
>among male power line workers than the background level (usually below
>the power lines with the upper torso exposed).
Ok, your TLD didn't seem to see any real difference, (otherwise
a study would have shown some kind of range of readings, with
higher readings nearer the lines/towers.) You then try using
various other meters until you get one that does indicate _something
is going on._
I've been working with various radiation measuring instruments
in various situations for some years now, and have only really
learned a few things.
o It's surprising how many non-ionizing or non-radiation effects
can screw up your instrumentation.
o Unless you have a very good idea of the actual composition of
the radiation you are measuring, you really can't grab any
instrument and accept it as true.
o TLD still is done best be users who are very careful in handling
of the material. Even then, a 30% higher reading on only one
chip would never be used as the only basis for a conclusion.
If you really think this is meaningful, try to get someone who
really knows dosimetry equipment, and get them to collaborate.
Frank R. Borger - Physicist ___ What's the best way to tune a Banjo?
Michael Reese - U of Chicago |___ With an Axe! - What's the difference
Center for Radiation Therapy | |_) _ between a dead skunk and a dead banjo
net: Frank@rover.uchicago.edu | \|_) player on the road? The skunk was on
ph: 312-791-8075 fa: 791-2517 |_) his way to a gig!