(an extension to the post "Beware of the Phone")
I was watching an episode of "The Practice" last night (American TV drama about a Law Firm), and it got my thinking (again). One of their cases concerned harmful radiation from power lines built through the clients' neighbourhood.
There were several cases of cancer and leukaemia involved, due to, they said, the "radioactivity" from the power lines.
There are two issues here: 1. The researchers got it wrong - "radiation" and "radioactivity" are two different entities. Power lines would emit only "radiation", NOT "radioactivity". 2. If there were any adverse effects from this "radiation", we should all have cancer by now from the same "radiation" that flies around the air from TV signals, radio signals, CB signals and of course, cellphone signals, not to mention the microwave ovens we place so near to us in our homes.
To clarify:
"Radioactivity" comes from the decay of atoms that split apart. If power lines were made of this kind of material, they would have fallen down long ago because all the atoms have decayed (loosely speaking). Only one kind of radiation comes from this source, and IS quite dangerous. They are called "gamma" rays.
"Radiation", however, is far more widespread, and what is more, most of what was encountered is made by man.
This kind of radiation, some of which is purposely made to be powerful enough to get to satellites 22,000 miles above us, is widespread.
* Radio waves - these come into your radios eg KLM FM
* Television waves - these come into your TV (although most in America come via cable now)
* Cellphone waves - how cellphones communicate
* CB waves - short wave radio for Citizen's Band
* Radio Ham waves - used by long-range enthusiasts (they bounce off the atmosphere to get round the curvature of the earth)
* Microwaves - from the home microwave ovens
The point is - All these waves are man-made, and yet do not seem to harm us (after all , TV waves have been going for nearly 80 years now). And yet, waves from power lines, lines which are actually designed to reduce wave emissions, if any, seem to concern people in that they may be harmful. No-one yet has ever claimed that TV waves cause cancer!!
Ok, now for the physics. These are all part of the "Electromagnetic Spectrum" - which is a bit like a normal spectrum but a lot larger. Here it is (notice how small the visible light region is)
For those of you who do not know:
UV - UltraViolet (beyond violet -invisible)
IR - InfraRed (before red - invisible)
UHF - Ultra High Frequency
VHF - Very High Frequency
SW/HF - Short Wave/High Frequency
MW/MF - Medium Wave/Medium Frequency
LW/LF - Long Wave/Low Frequency
LW/VLF - Low Frequency/VeryLow Frequency
ELF - Extra Low Frequency
SELF - ??? (never heard of that one!)
Notice one thing - the high frequencies have short wavelengths, the low frequencies have long wavelengths (broadly speaking). This is because of the simple wave equation for light, frequency x wavelength = the speed of light. Common sense really. If the wavelength is short, say, 10 cm, more of them pass you by in one second (high frequency) than a wave that is 1.6 km long (low frequency) because they all travel at the speed of light.
For the math, the E represents how many zeroes to add to get the number eg, 1E2 is simply "100" whereas 1E-3 simply means "(0).001".
The most important word in the whole picture is "IONISATION" on the right. This is the dangerous part.
Yes, it is quantum mechanics again, and it means that there is so much energy in the radiation that each quanta of it behaves like a particle and can knock electrons from out of atoms. This is what "ionisation" is. If you get electrons knocked out of YOU, it is called radiation sickness.
However, look where it happens, not in the cellphone region (the yellow), nor in the TV region (the UHF/VHF orange-yellow), nor even in the microwaves region (bright yellow) and certainly NOT in the power lines region (the red). Why? Simply because there is not enough energy in those regions to cause damage. Think of it like a cork on a deep ocean. Deep ocean waves are too big to affect a cork (They are at least 10 meters long), but put a cork in a puddle and stamp your foot in the same puddle nearby, the cork invariably jumps right out of the puddle.
This is because the "waves" are about the same size as the cork, and is the same reason ionisation occurs.
In other words, apart from nuclear physicists, we are all safe from everyday radiation, simply because there is not enough energy in them to cause damage.
Wednesday, October 15, 2008
Beware of the Power Lines
Subscribe to:
Post Comments (Atom)
5 comments:
So, how does one explain that over the years in more than a few scientific studies, it has been documented that people who live near the most powerful electrical lines--I forget the name of these, unless high voltage fits--there are higher incidences of cancer and leukemia than in the surrounding area? I also forget the distances involved, but think it was limited to a few hundred or a few thousand feet of these high voltage powerlines.
I would suspect at the genetic level some people are more susceptible to radiation than the average population, while some are less susceptible to radiation than the average population. This might skew such studies one way or the other.
Also, why do we have warnings on Microwave ovens if these are safe? These warnings, as I recall, were placed on the ovens because such ovens can't be guaranteed to be microwave leakproof, yet you seem to imply they are harmless. Also, what about Microwave TV and cellphone towers?
By the way, when I was a kid, it was often said you should sit at least 6 feet from a TV to avoid harm from picture tube emissions, which were cathode ray guns/tubes or whatever they called them. These were the old black & white TVs. I think when color TVs came along they either pushed back the distance you should be from the "tube" or raised the volume of their warning about staying 6 feet from the "tube". Old science, yes, but must have been based on something.
I continue to wonder, however resilient the human body truly is thanks to the natural environment it has had to learn to survive in, how various types of manmade radiation have added human harm to our environment; we simply have not teased out the details in my opinion. We have barely noted the affect of Greenhouse Gases in your lifetime that have been manmade and still can not predict with unqualified accuracy what will happen with X amount of these gases in the atmosphere. Should it surprise us, if, after an even longer search with radiation, we still can not fully fathom and predict the affects of manmade radiation?
I would say more, but I will leave it here for now. Thank you for an excellent post. By the way, I can't believe the TV program was idiot enough not to consult someone on the difference between radiation and radioactivity for a legal program, where definitions can often be the key to a case. Still, I loved the laugh and the groan I experienced at reading that error.
All I can say is that I have no fear of power lines any more than I do of cellphones!!!
In fact less so!!
But that is just one stupid scientist's view!!
Far be it for me to challenge mere statistics!!
You would not be the first foolhardy scientist to ever live. I think a number of the early nuclear scientists, brilliant as they were, could not grasp the dangers of the radioactive elements they worked with either. In fact, I think one famous fellow use to carry radioactive pellets or something like that in his pocket, tossing it/them in a drawer sometimes. I think this may have been how it was discovered that X-rays were good for viewing the bones of the human body.
I wonder how many scientists said things like "Rubbish" and "Balderdash" when the earliest Global Warming scientists brought that subject up. Now, it's the majority view. A good dose of skepticism is always warranted on both sides of an issue, because as Einstein showed, the majority opinion is not always right.
The reason why microwave ovens carry a warning is a simple "cya" option (Cover you ass).
This kind of feature is common amongst computer programmers.
There really is no danger, but if there were, the manufacturers will claim non-responsibility because of the "warning".
Economics, basically!
Lawyers lawyers, those wonderful lawyers. Yes, I think Amana, perhaps the original microwave oven people, were sued when it was discovered their microwave ovens were not so well sealed, thus leaked microwaves into nearby areas where a human might be standing. However, I thought some "mouse" studies did show potential harm from microwaves.
But, as I have e-mailed you a story of a brain study indicating that magnetism may relieve depression (and isn't magnetism a form of radiation), then why might it not do harm as well? And yes, I would appreciate it if other knowledgeable people would jump into this debate. I am tossing darts; some of which I feel hit the board. Besides, I'M RIGHT and you're WRONG. Thank you.
P.S.--I consider this a serious subject, because one interesting aspect of this is can "long waves" do damage to humans? If so, how and in what way? At the other end is the shortest of the short waves too. Then there is what has the human body developed almost 100% immunity to in this area. I don't think we have all the answers; while in many respects, we seem at the beginning, for all we do know.
Post a Comment