I have followed this "health effects of electric fields" thing for quite a
while. The other night, my wife was freezing in bed with a heap of covers
over her. This is her normal state, always cold. I told her to turn on
the electric blanket which was laying on top, unplugged. "No, I have
heard they are bad for you."
The last time I looked itno this issue it had been thoroughly debunked,
but has somehow got into the popular culture and just won't die. Anybody
heard any facts lately?
What do you all think about the wireless LAN effect on young kids? I
tried
resisting it out of the fear, but thinking to try it because of the wiring
hassle.
Thanks.
Ling SM
-- http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
Our monthly electric bill provides relative field strengths for a
variety of electric sources and also includes a disclaimer of
sorts. So it looks to me that there is still a little bunk left.
In any event don't overlook the hot water bottle.
As far as I know the loudest voice are all very sure that there is no
ill-effect. I have noticed quite a good numbers are "non-bias" studies
funded by Cellphone makers, Electrical companies, etc.
IEEE spectrum ran an article some months back about the possible ill-effect
about cellphone, and this invited strong debuttal from members of the IEEE
International Committee on Electromagnetic Safety , and from former and
current members of IEEE Committee on Man and Radiation (COMAR).
The latest response from the author published on Dec2002 issue of Spectrum
prompted my earlier question:
"The latest release of C95.1 was based on studies done in the 1960s through
1985. The baseline for the safety margin for near-field exposure in C95.1
cited by the members of COMAR is based on thermal damage to tissue. The very
timeframe of this research precludes the use of the advances in technology
and research techniques available today. Nor was this body of experiments
designed to study cellular-level damage from long-term, low-level exposure.
> I have followed this "health effects of electric fields" thing for quite a
> while. The other night, my wife was freezing in bed with a heap of covers
> over her. This is her normal state, always cold. I told her to turn on
> the electric blanket which was laying on top, unplugged. "No, I have
> heard they are bad for you."
>
> The last time I looked itno this issue it had been thoroughly debunked,
> but has somehow got into the popular culture and just won't die. Anybody
> heard any facts lately?
>
> -- Lawrence Lile
>
> What do you all think about the wireless LAN effect on young kids? I
> tried
> resisting it out of the fear, but thinking to try it because of the wiring
> hassle.
>
> Thanks.
>
> Ling SM
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>
> --
> http://www.piclist.com hint: The list server can filter out subtopics
> (like ads or off topics) for you. See http://www.piclist.com/#topics
One of the original studies to raise the alarm about this found a
statistical relationship between leukemia and proximity to electrical
substations. Another study found a statistical relationship between
electricians, electrical engineers and some form of cancer. Both studies
were later redone with larger population groups, more controls, and actual
measuring of electrical fields instead of conjecture, and found no
relationship. However, the cat was out of the bag and the public began to
panic.
My electric blanket says is it specifically designed to minimize exposure
to electric fields. Apparently the issue has Sunbeam scared, at least.
Frankly I wish there WERE some measurable health effect, I could make a
lot of money specifying 100% rewiring of all commercial buildings!
To: PICLISTspam_OUTMITVMA.MIT.EDU
cc:
Subject: Re: [EE]: Health effects of electric fields (was any design Idea in new
house.)
As far as I know the loudest voice are all very sure that there is no
ill-effect. I have noticed quite a good numbers are "non-bias" studies
funded by Cellphone makers, Electrical companies, etc.
IEEE spectrum ran an article some months back about the possible
ill-effect
about cellphone, and this invited strong debuttal from members of the IEEE
International Committee on Electromagnetic Safety , and from former and
current members of IEEE Committee on Man and Radiation (COMAR).
The latest response from the author published on Dec2002 issue of Spectrum
prompted my earlier question:
"The latest release of C95.1 was based on studies done in the 1960s
through
1985. The baseline for the safety margin for near-field exposure in C95.1
cited by the members of COMAR is based on thermal damage to tissue. The
very
timeframe of this research precludes the use of the advances in technology
and research techniques available today. Nor was this body of experiments
designed to study cellular-level damage from long-term, low-level
exposure.
Ling SM
> I have followed this "health effects of electric fields" thing for quite
a
> while. The other night, my wife was freezing in bed with a heap of
covers {Quote hidden}
> over her. This is her normal state, always cold. I told her to turn on
> the electric blanket which was laying on top, unplugged. "No, I have
> heard they are bad for you."
>
> The last time I looked itno this issue it had been thoroughly debunked,
> but has somehow got into the popular culture and just won't die. Anybody
> heard any facts lately?
>
> -- Lawrence Lile
>
> What do you all think about the wireless LAN effect on young kids? I
> tried
> resisting it out of the fear, but thinking to try it because of the
> hassle.
>
> Thanks.
>
> Ling SM
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>
> --
> http://www.piclist.com hint: The list server can filter out subtopics
> (like ads or off topics) for you. See http://www.piclist.com/#topics
How about the long term effects from exposure to fields on the order
of 50kV/meter?? All external fields are ORDERS of magnitude SMALLER than
the fields the body generates internally as muscles and nerves operate!
The external fields are just minuscule noise by comparison. I should know,
I work in Neuroscience and recorded muscle and nerve signals for a living.
Many EMF studies have neglected to look at the effects of cosmic radiation
being focused by the M fields of parallel power lines. Wireless World (UK)
had a series of letters on this effect back in the early '80s.
IMO it's not the EMF that is the problem. It is the focusing effect on
external radiation sources.
Most studies have NOT convincingly eliminated OTHER causes (Cosmic rays,
Radon, etc.).
And the irony (hypocrisy??) is that the very people who are screaming the
loudest about the dangers are the same ones who let their children watch
TV 4' from the screen, where the EMF is about 3 times as high as from a
HV power transmission tower. Or who use old computer screens and thereby
expose themselves to 10 times the EMF of a HV power tower.
Robert
Fed up with the hypocrisy of the EMF hysterics.
>
> As far as I know the loudest voice are all very sure that there is no
> ill-effect. I have noticed quite a good numbers are "non-bias" studies
> funded by Cellphone makers, Electrical companies, etc.
>
> IEEE spectrum ran an article some months back about the possible ill-effect
> about cellphone, and this invited strong debuttal from members of the IEEE
> International Committee on Electromagnetic Safety , and from former and
> current members of IEEE Committee on Man and Radiation (COMAR).
>
> The latest response from the author published on Dec2002 issue of Spectrum
> prompted my earlier question:
>
> "The latest release of C95.1 was based on studies done in the 1960s through
> 1985. The baseline for the safety margin for near-field exposure in C95.1
> cited by the members of COMAR is based on thermal damage to tissue. The very
> timeframe of this research precludes the use of the advances in technology
> and research techniques available today. Nor was this body of experiments
> designed to study cellular-level damage from long-term, low-level exposure.
>
> Ling SM
>
> > I have followed this "health effects of electric fields" thing for quite a
> > while. The other night, my wife was freezing in bed with a heap of covers
> > over her. This is her normal state, always cold. I told her to turn on
> > the electric blanket which was laying on top, unplugged. "No, I have
> > heard they are bad for you."
> >
> > The last time I looked itno this issue it had been thoroughly debunked,
> > but has somehow got into the popular culture and just won't die. Anybody
> > heard any facts lately?
> >
> > -- Lawrence Lile
> >
> > What do you all think about the wireless LAN effect on young kids? I
> > tried
> > resisting it out of the fear, but thinking to try it because of the wiring
> > hassle.
> >
> > Thanks.
> >
> > Ling SM
> As far as I know the loudest voice are all very sure that there is no
> ill-effect. I have noticed quite a good numbers are "non-bias" studies
> funded by Cellphone makers, Electrical companies, etc.
I would be cautious of the use of "non-bias" and "funded by" in the same
arena.
> The latest response from the author published on Dec2002 issue of Spectrum
> prompted my earlier question:
>
> "The latest release of C95.1 was based on studies done in the 1960s
through
> 1985. The baseline for the safety margin for near-field exposure in C95.1
> cited by the members of COMAR is based on thermal damage to tissue. The
very
> timeframe of this research precludes the use of the advances in technology
> and research techniques available today. Nor was this body of experiments
> designed to study cellular-level damage from long-term, low-level
exposure.
Indeed.
Thermal effects are (probably) not the issue, but are what much earlier
studies focused on.
> I have followed this "health effects of electric fields" thing for quite a
> while. .....
> The last time I looked itno this issue it had been thoroughly debunked,
> but has somehow got into the popular culture and just won't die. Anybody
> heard any facts lately?
There have been numerous peer reviewed studies done in this area.
A large proportion report no significant effects.
A large proportion report significant effects.
The jury is still out, IMHO.
Do note that, in this as in many areas, there is some correlation between
who a researcher is funded by or the researchers special interests, and the
outcome of the studies. (eg industry funding, evangelical greeny etc).
It makes great sense (to me at least)* that there MAY be effects and it is
easy to reduce you long term day to day exposure to a level consistent with
your mean environment. If you want to you can reduce the level of your mean
environment but this takes extra work and a change of lifestyle. All it
needs to practice "prudent avoidance" is simple things like seeing if your
house has split wiring loops (which cause you to live inside a large EM
generating loop) and getting a feel for how far you need to be from an
appliance before the field falls to local background. A basic field strength
meter (as per several refs posted here in last day) will tell you all this.
I live a few houses away from, but not under, high voltage power lines. A
wander around the neighbourhood with an EM meter (who was that funny man
with the tinfoil cap mummy?) (that was Jinx dear :-) ) showed the limits
beyond which the power lines effect was not discernible compared with that
from street wiring and house wiring. There ARE possible second order effects
from power lines which depend on their physical magnitude and which cannot
be measured by a basic meter alone - eg lensing/sweeping/focusing of
background cosmic radiation. This has been both proven and debunked by
various studies :-(.
As an example from another discipline (an excellent one I feel) of how one
needs be wary of epidemiology, consider: The town of Sellafield (previously
Windscale?) has a clusters of childhood cancer with levels several times
that of the UK national average. The town hosts the UK's nuclear waste
reprocessing plant. Correlation at first appeared to relate to parental
(father's) exposure to radiation. Some experts posited other mechanisms to
explain this (other experts have since said they were wrong). NO radiation
clusters have been found to match the cancer clusters. (some) Experts have
concluded that the nuclear fuel reprocessing plant and/or radiation is
therefore not a factor in the cancer.
Questions:
How many of you believe them?
Would you take your family to live in Sellafield?
Which side of the prudent avoidance line would you wish to err in this
case?
Google gives 7000+ strikes for Sellafield Cancer.
Here's the first one.
* - The human body depends utterly for its operation on low level electrical
signals. The ability to influence bodily functions by applying external
electromagnetic and electrostatic fields *of sufficient magnitude* is
unquestionable. The *possibility* of small level fields causing long term
changes seems unquestionable. Taking the most simple of steps to avoid the
more extreme unnecessary exposures seems wise.
> IMO it's not the EMF that is the problem. It is ....
Indeed (again :-) ).
WHAT the mechanism is or may be is not the issue,
It's whether there IS a mechanism at all.
In the mean time, taking simple essentially cost free steps to avoid what
appear to be the most likely areas for mechanisms to act in seems wise.
At 01:20 PM 03/01/03, you wrote:
> > IMO it's not the EMF that is the problem. It is ....
>
>Indeed (again :-) ).
>WHAT the mechanism is or may be is not the issue,
>It's whether there IS a mechanism at all.
>In the mean time, taking simple essentially cost free steps to avoid what
>appear to be the most likely areas for mechanisms to act in seems wise.
>
> RM
Then there is public perception of a risk that may or may not be there.
Remember the big craze about having to have a low radiation monitor a
few years back?
If you owned a computer store you couldn't stock enough of them to
sell to people until one of the local government agencies did some
testing (later confirmed by others) that there was no discernable emf
emissions from the monitor past about 8cm from the glass
(if I recall correctly). The low rad monitors were almost identical
(except you could sell them for more). I've only ever seen one person
who had sight problems (legally blind) who would have to read text with
his nose touching the glass. Everyone else sits a good arms length away.
I've seen a similar test of the em fields around the hi tension towers. The
field was quite a bit bigger but they claimed to extend only a few meters
around the wire. Ask any farmer who has milk cows if they react or behave
differently when pastured next to towers and they will claim they do. I had
a friend who lived with towers in the backyard. He was pretty weird so O'm
convinced ;-]
I have been involved in EMF-problems for the last 10 years. As of now, we don't know all effects emf have on biological life, but we do know that there are thermal effects, and more and more studies seem to find non-thermal effects as well.
I think that many of us make a mistake when discussing these problems. Many of the debates tend to focus on people's worries for the health effects of EMF. Personnally I think we must take their worries seriously, but what we forget is that there are quite a lot of people experiencing rather severe symptoms when they are exposed to non-thermal levels of EMF. Their symptoms are not caused by worries.
I work with low-emf equipment and measurement instruments , I measure EMF fields in varoius places and make analysis of the environment in houses, offices, cars etc. What I have seen is that in 90% of the cases when people have reported symptoms which they suspected to be caused by EMF, there were quite high levels electric and/or magnetic fields, still below thermal levels. Fields that are 100% invisible for each and everyone without a field strength meter. My conclusion is that there must be a mechanism in the human body which acts as a receptor for electric and magnetic fields, on some individuals. I just can't find any other explanation to it.
I can take one example:
A customer, with two houses, told me that felt really bad in one of them but not in the other. He couldn't find any reason at all for this, and consulted us to perform a measurement. He is not a technician, and don't understand the mechanisms of EMF, by the way. So, we started to measure and found a magnetic field, in the house where he felt bad, with peaks around 40 uT, and average levels around 20 uT. The other house had levels below 10 nT , i.e. almost nothing. We did some fault finding and located a cable. This is one of the "worst" cases, but as I said, it's more or less the same in 90% of our cases.
I don't claim to be a researcher or a physician, but in my opinion, this is evidence enough to prove that there are non thermal effects, and that electrosensitivity should be taken seriously.
>I've seen a similar test of the em fields around the hi tension towers.
The
field was quite a bit bigger but they claimed to extend only a few meters
around the wire. Ask any farmer who has milk cows if they react or behave
differently when pastured next to towers and they will claim they do. I
had
a friend who lived with towers in the backyard. He was pretty weird so O'm
convinced ;-]
Now there was a fellow busted in Missouri for the following stunt. He
hooked a loop of electric fence wire so that a section of it ran directly
under high tension wires, then the ends looped back to his barn to run his
barn lights. He raised the fenceposts up to about 10' in the air, and
fiddled with it until he got a good strong 120VAC in the barn.
He was caught because his barn burnt down. Seems an ice storm lowered the
high tension wires, raising the voltage int he barn and eventually causing
a fire when it arced over. The fire marshal got really suspicious when
there was no power hooked to the barn and an electrical fire inside. Yes
there is a signifigant em field under power lines, at least this fellow
found out there was!
People's behavior around this issue gets a little irrational. An electric
blanket is bad, a computer monitor is OK. A toaster is OK, bare elements
and all, as is a TV or a CB radio, but a cell phone is bad. Most house
wiring runs two grounded wires with a hot wire, a good way to neutralize
fields (not as good as grounded conduit)
At 01:20 PM 03/01/03, you wrote:
> > IMO it's not the EMF that is the problem. It is ....
>
>Indeed (again :-) ).
>WHAT the mechanism is or may be is not the issue,
>It's whether there IS a mechanism at all.
>In the mean time, taking simple essentially cost free steps to avoid what
>appear to be the most likely areas for mechanisms to act in seems wise.
>
> RM
Then there is public perception of a risk that may or may not be there.
Remember the big craze about having to have a low radiation monitor a
few years back?
If you owned a computer store you couldn't stock enough of them to
sell to people until one of the local government agencies did some
testing (later confirmed by others) that there was no discernable emf
emissions from the monitor past about 8cm from the glass
(if I recall correctly). The low rad monitors were almost identical
(except you could sell them for more). I've only ever seen one person
who had sight problems (legally blind) who would have to read text with
his nose touching the glass. Everyone else sits a good arms length away.
I've seen a similar test of the em fields around the hi tension towers.
The
field was quite a bit bigger but they claimed to extend only a few meters
around the wire. Ask any farmer who has milk cows if they react or behave
differently when pastured next to towers and they will claim they do. I
had
a friend who lived with towers in the backyard. He was pretty weird so O'm
convinced ;-]
If it's any type of EM field, think about the MRI scanners in a
hospital. The personnel that run those things sit in a HUGE field all
day long. When the MRI runs that field is shifting tremendously. At last
look they wear no monitoring devices of any type. That would tend to
discredit any type of adverse physiologic effect due to those types of
fields. However, you will always find a few who disagree.
Gary.
techhead wrote:
>
> If it's any type of EM field, think about the MRI scanners in a
> hospital. The personnel that run those things sit in a HUGE field all
> day long. When the MRI runs that field is shifting tremendously. At last
I can vouch for the strength of the field. Wiped out my magnetic card
stripes from about 6' away (I crossed the rope to get a closer look at
the RF power amps).
Also made the keys in my pocket tug toward the core. I quickly
crossed back to where I was supposed to be <G>. I was amazed at
how much magnetic leakage there was.
> look they wear no monitoring devices of any type. That would tend to
> discredit any type of adverse physiologic effect due to those types of
> fields. However, you will always find a few who disagree.
Of course. And if they ever DO find a 'proven' problem, you can bet
that the lawsuits would be flying faster that the magnetic domains flip.
> I've seen a similar test of the em fields around the hi tension towers.
The
> field was quite a bit bigger but they claimed to extend only a few meters
> around the wire.
Must have been done my a researcher funded by the power companies :-)
Numerical details below are vague as I forget as it was perhaps 10 years ago
that I measured them.
As previously noted, I have HV lines near my house.
Wires are around 80 feet above ground AFAIR where they cross the street at
an angle.
Lines are 220 kV I think
I made a simple field strength meter and wandered around my house, my
section and the neighbourhood.
Fields directly under HV lines were substantially in excess of those in my
house from 230V power wiring.
Measurable fields in excess of normal domestic extended for about 1
"section" beyond centreline of power lines.
Took a drive with an EM field meter in the car.
Crossing pylon routes were instantly noticeable.
There were also a few very large readings with no visible source. I would
expect buried power cables to have balanced feed in close proximity so this
was surprising.
Does it all matter? - I don't know.
MIGHT it matter significantly? - I believe it MIGHT.
Is it trivially easy * to take basic precautions? - yes.
Russell McMahon
* - trivially easy compared to the POSSIBLE worst case outcomes. Only a
minor effort and expense in absolute terms.
A Google search on "diathermy" produces nearly 23,000 hits. Most of those I
read seemed to offer insight into this subject.
The possibility of reacting with implants introduces a new concern.
John Ferrell
6241 Phillippi Rd
Julian NC 27283
Phone: (336)685-9606
Dixie Competition Products
NSRCA 479 AMA 4190 W8CCW
"My Competition is Not My Enemy"
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