Conference moira::parenting

    We moved into our house 3 years ago now, and every now and then
    I again feel a little concern about the fact that the hi-tension 
    power lines run behind our house, in a small strip of green space
    between our yards and the condos on the other side. 
    My husband though, seems unconcerned, having discussed this with the 
    high-energy physicists he works with (he supports their DEC machines).
    They basically say that exposure is lessened dramatically the further
    you are from them. At the distance we are, it probably more dangerous
    to use a hair dryer every day. 8-).
    
    Perhaps for your own piece of mind, you may consider calling a health
    agency in your area. 
    
    Monica

You may wish to check in the MEDICAL conference.  There was a discussion in
there a few months ago...

- Deb

    I don't know much about them except that from the reports I've seen
    on TV, the potential danger is increased proportions of Leukemia.
    
    Maybe you could check the library for articles on leukemia ??
    
    

    Thanks for the replies so far.  Can someone tell me what node MEDICAL
    is on?
    
    Thanks,
    
    Sheryl

    The majority of data around health effects of high tension lines
    is epidemiological (observing the statistical correlation of health 
    problems with location of power lines).  Epidemiological data is 
    generally considered insufficient by itself to establish a definite risk 
    unless accompanied by a plausible causal mechanism, because of the
    complexities in interpreting statistical correlations.  
    
    There are researchers currently working to try to establish a causal 
    mechanism between high tension lines and health problems, especially since 
    a number of the epidemiological studies showed evidence of serious health
    problems.   However, at the present, there is not a strong enough link
    established to say with certainty that the power lines were the most
    significant causal agent in the health problems.  The epidemiological
    data is somewhat ambiguous, from what I've seen.  There are studies
    showing high statistical levels of disease, but most have been criticized 
    on the basis that other factors were just as likely to have been at fault.
    
    On the other hand, the public perception is that high
    tension lines anywhere near the vicinity are dangerous, and this will
    at the very least cause the property to be harder to sell, and 
    will always leave you wondering, if you ever become seriously ill, 
    whether the tension lines (or even just worrying about them) was a factor.
    	
    Those are not minor considerations.  An imagined 'ghost' can sometimes
    cause just as much damage as a real one would.  And this one may or
    may not be imaginary.
    
    						kind regards,
    
    						todd

    re: .4,
    	VMSZOO::MEDICAL, topic 1488.* .
    
    	"Press <SELECT> or <KP7> to add MEDICAL to your notebook."
    
    						todd

      RE: .0
    
    One thing you can do before signing (or having as a stipulation in the
    P&S) is that you can have the local electric company come to the
    house and have the Electro Magnetic fields measured.  It's free of
    charge.  It seems that the EMF's are the culprits (or rather, the
    perceived culprits) to certain diseases.  I had my house measured
    after watching segments on different shows (including Good Morning
    America) on EMF's.  One couple's daughter had behavioural 
     (and eventually physical) problems and the couple, as a last ditch
    effort to find out what was wrong, had the house measured.  The
    daughters room was rated at over 80 EMF's!  (perceived safe range is 2!).
    They corrected the problem (which was cause when they had
    renovations done to the house and the house was improperly wired
    and all the wiring came together outside the daughters bedroom and
    they also had wire problems under their patio, where the daughter
    played and rode her bike [the patio came in at around 250 EMF's!]).
    
    Now there are no behavioural problems, they said that the daughters 
    behaviour problems seemed to disappear over night - they said it was a 
    rather dramatic change in their daughter.
    
    Call the local utility company for a rep. to come out and measure.
    (BTW, I was told that there's nothing that can stop EMF's in our
    living environments, walls are not deterents for these fields).
    
    FWIW.                                   
    
    NF
    not deterents,
   

    As .5 explains the jury is still out.
    
    I look at it this way:  There IS some indication power lines may be 
    dangerous, and the public is wary of them.  If you buy a house near
    them at the least you will have trouble selling it.  When the jury
    comes back in, what if power lines ARE proven to be risky for leukemia?
    
    Why set yourself up for future problems?  I suggest you buy\rent
    housing remote from powerlines.
    
    Actually the high tension (voltage) isn't the issue.  Its actually
    the high CURRENTS that high tension powerlines carry because the
    strength of the electomagnetic field is proportional to the current
    the conductor is carrying.
    
    Secondary mains 120/240 volt (the twisted black leads that lead into
    factories and homes) are suspect too because they usually carry
    relatively high amperages.
    
    It would be smart to keep you kid(s) beds as far away from the secondary
    mains coming into your house as possible, or at right angles (not 
    parallel) to the mains as having the beds at right angles helps
    decouple them electromagnetically.
    
    (This sounds like science fiction stuff I know) but there ARE concerns
    and doing the above will reduce the risk IF the leukemia like proves
    to be true.  At the worst, 'decoupling' the kids and moving them away
    won't hurt anything.  I have moved my sons bed at right angles to the
    secondary main on the outside of my house. The walls don't count..
    electromagnetism will pass right through wood and ordinary home
    construction materials.
    
    Distance is everything... the further away the better. For every 
    doubling of the distance the strength of the field goes DOWN FOUR
    times.  
    
    Electric blankets are thought to be risky because they are so CLOSE
    to your body (distance again) even through the currents are relatively
    low.
    
    Also, secondary mains which have the twisted black leads with an 
    aluminum support wire and ground which typically lead from the street
    to your house are not as risky as SINGLE wire (typically several wires
    run next to one other) because the electromagnetic field tends to be
    cancelled out because the wires are in close proximity to one another.
    
    I know, I know it sounds like a bunch of technical garbage only a
    science fiction writer could come up with but the thinking as I
    understand it is illustrated in part in my above explanations.
    
    (Yes, I do have a professional background in power wiring).
    
    If I owned or rented immediately adjacent to high tension lines I would
    sell or move out.... for sure.
    
    Jeff

    I agree with .8.  Why put yourself at risk?  This is a buyer's 
    market.  There are plenty of good houses out there.  I would avoid
    this one.
    
    Wendy

    re: .7,
    
    Yes, actually the causal link to behavioral problems from intense
    fields is generally considered even more plausible than that
    to blood diseases, because of the largely electrical nature of
    the nervous system, and because other data supports the fact of
    electromagnetic fields influencing brain functions.  The problem with the 
    link to blood diseases is that a mechanism for the field interfering with 
    biochemical cellular processes would need to be established, to be
    fully convincing, and this is harder to do.
    
    I agree with the previous as well.  Quantify the risk
    (get the field measured), and don't take unneccessary risks in an
    uncertain situation like this if the field strength is very high.
    
    						todd

To the person who had their house measured, the Magnetic
field strength is normally measured in Gauss (an older CGS unit) or
Tesla (the modern SI or MKS) unit.  I don't know what the measurement
you were given is, but you must ensure that you are comapring apples
with apples and oranges with oranges.  ie make sure that your unit
is teh same as your safety reference when you are comparing.

Electrical field strength (the other possible measurement) is usually
Volts/metre or Volts/cm.  It is unclear as to whether this poses a
health threat ... generally the magnetic field is considered the more
likely source of danger, because with alternating current, that field
is collapsing and reversing 60 times per second.  BUT it is still
inconclusive.

Your readings of so many EMFs could be anything ...

Also remember that your high readings may not occur all the time ...
if your house is electrically heated, chances are that there will
be higher fields, but only when the heat is on.

It would be normal to assume that power company workers should have higher
rates of cancer, since they often work in very high field strength areas,
but no such results have been reported.

This whole thing is so grey ... but I'm inclined to agree with the
person who indicated as long as power line fear exists, it will be
more difficult to sell those houses.  There are plenty of other culprits
in terms of high field strengths inside the home, so, I certainly
would not worry about lines, but power lines are visible ...

Stuart

    
    the field strength decays as a square of the distance from the source,
    so 10 ft away you get x whatevers, 100ft away you get square root of x
    whatevers.
    
    Anyhow, never mind science onto emotion. I would expect in a few years
    the debate will go one way or another. If you are going to be in the
    position of selling this house around the same time (say 5 years) then
    you could be in jeoperdy of not being able to sell for anything!
    
    Its seems the 80s and the 90s are times when things we took for granted
    in the name of progres (lead paint, toxic chemicals) actually turns
    around to have a nasty downside. Given this prevailing atmosphere I
    wouldn't like to buy a house in the potentially next frontline.
    
    In Colorado Springs the Utilities department has agreed to bury all
    future neighbourhood lines, and most future high-tension lines.
    
    Simon

    Recent issues of _Science_News_ have had articles on this.
    
    		-John Bishop

    We have friends in town who own likely the most beautiful house,
    and house location, in our area.  But they power lines in their
    back yard.  They are trying to sell their house and are finding
    that many people are frightened off by the power lines.
    They are having a hard time selling it.
    bob

    One thing about power lines Stuart is that high tension lines are
    always 'on' and often heavily loaded which is unlike some of the point
    sources in your house. Electric heat is not always on for example. By
    on I mean carrying relatively high amperages, not just energized.
    
    Some studes have indicated power industry workers have higher blood
    cancer rates, but then, other studies of the industry show now
    increase.
    
    This whole controversy started in I think, Colorado when a woman
    looking for the reason(s) for a cluster of high leukemia rates noticed
    that many of the homes with higher leukemia rates had high amperage
    secondary mains (for factories) running adjacent to the homes in
    question.  There was far more detail in the article and I can't
    remember all the details but the end result was convincing that perhaps
    the power lines were responsible.  Still, that was one study, other
    studies have found no co-relation and jury is still out.
    
    One thing to remember is that the power industry would tend to want to
    suppress info like this (bad for business to say the least, and
    retrofitting the power distribution system expense would strain the
    national budget!)...... so I would think the power industry would
    proceed carefully to say the least...  So, when the electric power
    industry reports  "Our studies indicate no corelation" it makes me
    wonder just how reliable their studies are?!
    
    The studies should be done by 'non involved parties' who can't be 
    paid off.
    
    Just the facts please.
    
    Jeff
    
    

re .12:
    
>    the field strength decays as a square of the distance from the source,
>    so 10 ft away you get x whatevers, 100ft away you get square root of x
>    whatevers.
 
Actually, if the measurement is x at a distance of 10 feet, it should be x/100
(not sqrt(x)) at a distance of 100 feet -- increasing the distance 10-fold
should decrease the field strength 10^2 = 100-fold.

But does the inverse square law really apply here?  My recollection is that you
have an inverse square law for point sources, but a simple inverse for linear
sources (and a constant field strength from a planar source); and a power line
sounds like a linear source to me.

	-Neil   

    
    you knw, I knew I was going to get jumped on. yes you're right, move
    twice the diustance away and the ield strength is 1/4 of the origianl,
    and so on!
    
    Anyway, since when was buying a house scientific? I bought mine because
    of a cute inlaid china cabinet, never mind anything else!
    
    Simon

Power lines are more complex than that, strictly, the field from the
3 conductors, if all at the same physical point (ie a tight bound cable)
would and should sum to zero providing their currents were equal. (Usually
power lines are 3 phase.

In a house service entry, most houses are supplied with so called split
phase --- 180 deg apart .... but again, from a supply cable it should
sum towards zero ... viz low net fields ... again providing the house load
is properly balanced.

How this is complicated by the neutral being tied to ground, I'm not sure,
but undoubtedly it will be.

So, a lot of the field you see is in fact 2nd and 3rd order products.
Yuchhh ... work that arithmetic out!

Stuart

    Up until about a year ago I scoffed at the people who believed that
    high-tension wires posed any danger to humans. After all, I grew up six
    houses from high-tension wires and attended an elementary school right
    next to the same wires. Then I found out that a childhood friend--who
    lived *next to* the wires and attended school with me next to
    them--died the year before from leukemia (talk about sad--he was a
    doctor who diagnosed his own disease). Coincidence? Who knows. But I'd
    think twice before living too close to them.
    
    BTW, several houses on my parents' street (one two houses from the
    wires; the other three houses away) have been on the market for many
    months now with little or no interest. A deal on the house next door to
    my parents (the sixth house from the wires) fell through because the
    buyers got cold feet about living near the wires (SIX houses yet--and
    this is a very nice neighborhood!) So earlier comments about property
    values have merit.
    
    Good luck.
    
    Nancy- 

    Right Stuart, as long as the load is BALANCED their will be no current
    in the neutral... and as long as the 'twisted pair' are geometricall
    arranged (no uneven twists please) so that the fields DO cancel out.
    
    I think the point that twisted conductors with opposite currents TEND
    to cancel the fields of one another out can be said.
    
    Actually, we should all convert to D.C., then we only have to worry
    when switching things off and on.
    
    Jeff

    
    
    For whatever it is worth;
    
    	When we were looking at houses, we saw some nice, new developments,
    that had nice, new houses located under or near power lines.
    
    	We nicely drove on by.
    
    				Wendy

    I don't percieve a problem with selling a house in this area near
    power lines. As Stuart will attest, Nepean and Kanata, the suburbs
    where we live, are in fact very popular places for housing developments
    to be within site of high-power lines. 
    I stick to my original advice here - check with a health agency.
    Perhaps review the selling history of the houses in the area with
    your agent if re-saleability is your worry. Finally, go with your
    feelings; if this DOES bother you, it will not STOP bothering you
    when you have bought this house.
    
    This reminds me so much on the debates on whether any or all of the 
    following will negatively affect your health: CRTs, CarPhones,
    Waterbeds, the Pill, hair-dryers, non-organically grown vegetables, 
    tampons, and television (to name but a few 8-) ).
    
    *sigh*.
    
    Monica
    
    

    
    Re: .11
    
    Yes, Stuart, we made sure about the apples to apples comparison.
    Thanks for pointing that out to people.  
    
    I had the house measured every possible which way.  With the microwave 
    on - near it, away from it, all the appliances (tv. hair dryer,
    furnace, fridge, humidifier, can opener, you name it - all near and from 
    the center of the room).  In fact, the person who did the readings wrote 
    up his findings and had it printed up and sent to me.  I had my hand 
    written readings and compared it to his printed out ones and it was right 
    on.  It's about 7 pages long with the different readings!  It's a good 
    reference point.  Wow, the can opener and oven and hair dryers are really 
    "hot" when they're in use.  High readings.  Luckily they're not in 
    constant use!
    
    He stayed and did any reading I asked him to.  It lasted about
    1 1/2 hours to 2 hours.  I had alot of questions. Interesting stuff!
    
    Nancy

The idea of going DC is certainly a reasonable one ... in fact many extra
high voltage transmission lines in Britain are DC.  But, a DC transmission
line still generates a magnetic field ... just a constant one as opposed to
the alternating field.  Then the question is, just how much exposure can
cuase problems, and is there a threshold of exposure, in terms of minimum
exposure levels, in terms of single exposure duration, multiple exposure
duration and so on and so on.

The tough part is that there is an inconclusive link already ... how is
anyone going to measure these other parameters given that they can't prove
that static or dynamic fields already cause a problem !

Many motors have stray fields ... remember a motor is designed to create
magnetic fields ... so I'm not surprised at all that devices like electric
can openers have high stray fields ... generally, the cheaper and less
efficient the motor, the higher the stray fields.

When you add the internal house fields with the hydro line fields, you
are again presenting a big unknown ... there is no way of knowing the relative
phase of the fields, knowing whether the fields may cancel or add at any
given time and relative loads.

It is assumed that the H fields (Magnetic fields) are the ones that may
cause the problems ... but there is still no clear evidence that the E
fields may not be responsible, and these are measured totally independent
of one another.  

In terms of choosing a house ...

	. if they were more than 150 feet away
	. unless they were an eyesore
	. worry unless I knew I was likely to have to sell the house in a hurry.

then I wouldn't be worried, unless I had other doubts about the house. Other-
wise, I'd let the house decide.

This is all a part and parcel of the risks of late 20th century living.
If living doesn't kill you, you'll live 'til you die!

Stuart

    Regarding D.C. fields that word EXCEPT means alot.  i.e. with constant
    currents D.C. fields are stationary (assuming no ripple).  It is
    believed that induced currents in people and animals via the changing
    magnetic fields may be responsible for the physiological effects in
    humans and animals.  If the field is stationary there are no induced
    currents.  I don't know much research has been done on the effects of
    stationary magnetic fields.  But there is a big difference between
    stationary and changing magnetic fields regarding possible health
    effects. After all, many A.C. devices DEPEND on magnetic induction to
    operate, i.e. transformers and induction motors to name a couple.
    
    Yes, D.C. motors do have changing fields but we were discussing power
    mains.
    
    I understand that electric shavers may be risky because f the CLOSE 
    proximity of the shaver to ones' thyroid gland while shaving.
    
    Yes, living can be risky... after all we will all live till we die.
    
    But.... why die sooner and of a degenerative disease?
    
    Jeff

    Hi, it's the basenoter here.  We've decided not to buy the house.  Even
    though the house is about .2 mile from the wires, and we wouldn't be
    able to see them from the house, we'd have to drive by them to get into
    the development.  Even though the house we had in mind might be a safe
    distance, it's in a neighborhood and we can't guarantee that our kids
    wouldn't be best friends with the children whose homes are directly in
    front of the wires. (Of course we might buy in a completely different
    part of town and our kids still might be best friends with those near
    wires, but we'll deal with that if it happens.)
      
    We figure we'd better be safe than sorry and not
    take the risk of health hazards or having difficulty with resale.  
    
    I really appreciate everyone's comments and concerns.  Now, if someone
    could tell me the node that REAL_ESTATE is on now, we'll continue our
    hunt for the "child-safe" home!  
    
    Thanks!!
    Sheryl
    

    For those seeking information about EMF's there's an article in
    a recent issue of Science News, within the last month or so.
    
    The article does NOT address the issue of whether or not EMFs are
    harmful.  There is currently much controversy regarding this.
    
    The group who did the report took it upon themselves to learn
    as much as they could about the details of EMFs with respect
    to the home and office environment.
    
    Read the article if you want to find out the details about EMFs
    generated by common appliances, tools, etc.
    
    I certainly hope that the controversy regarding whether or not
    EMFs are harmful gets settled soon.