Cell phones & brain

[arcticpenguin]

http://news.bbc.co.uk/1/hi/health/2728149.stm

A new study says cell phone use could damage parts of the brain and "may trigger Alzheimer's".

I am skeptical. The study was done on rats. Even if the brain organization in rats is similar, the thickness of the skull is certainly different, which would make a difference in shielding.

[scotth]

What I have not seen in any of these "studies" is a plausible damage mechanism.

I may be missing something, but I know RF radiation pretty well as a Radar tech for 8 years.

The problem:

There are two ways that I can think of for tissue damage of any kind to occur.

1) Having a single photon of high enough energy to break a chemical bond. This is completely dependent upon frequency. X-rays and such clearly cross this threshold. Cell phones are well below this threshold.
2) Heating damage. You can damage a material by heating it enough. You have skin on your skull that would feel noticable pain if it was being heated enough to damage it. It would be odd to think that your brain might be heated to a greater degree than tissue closer to the source.

Cell phones do not put out a directional or focused RF beam, so, the surface of your head should obviously be heated the most. The frequency of the RF is well below the ionizing threshold. I can't imagine what could cause the damage.

Maybe there is another mechanism that I can't think of. Any physicists out there have another idea?

[pgwenthold]

Quote:

Originally posted by scotth
What I have not seen in any of these "studies" is a plausible damage mechanism.

I may be missing something, but I know RF radiation pretty well as a Radar tech for 8 years.

The problem:

There are two ways that I can think of for tissue damage of any kind to occur.

1) Having a single photon of high enough energy to break a chemical bond. This is completely dependent upon frequency. X-rays and such clearly cross this threshold. Cell phones are well below this threshold.
2) Heating damage. You can damage a material by heating it enough. You have skin on your skull that would feel noticable pain if it was being heated enough to damage it. It would be odd to think that your brain might be heated to a greater degree than tissue closer to the source.

Cell phones do not put out a directional or focused RF beam, so, the surface of your head should obviously be heated the most. The frequency of the RF is well below the ionizing threshold. I can't imagine what could cause the damage.

Maybe there is another mechanism that I can't think of. Any physicists out there have another idea?

Will a chemist due?

It all depends on the wavelength. Most organic molecules absorb all over the spectrum, except for the visible region (which is why eyes are so spectacular - when you get molecules like rodes and cones that can absorb in the visible, it gives you a huge advantage). So tell me the wavelength, and I'll tell you the potential mechanisms for creating damage.

You have mentioned x-ray, which is enough to break bonds, but that's not the problem here. Your comment about heating is a little non-specific. There are different types of heating you can have, including microwave, IR, or UV (which burns moreso than heats).

You are correct that there is no reason to think that any of these types of radiation would affect the brain without affecting the skin or surrounding tissue.

[scotth]

Quote:

Originally posted by pgwenthold


Will a chemist due?

It all depends on the wavelength. Most organic molecules absorb all over the spectrum, except for the visible region (which is why eyes are so spectacular - when you get molecules like rodes and cones that can absorb in the visible, it gives you a huge advantage). So tell me the wavelength, and I'll tell you the potential mechanisms for creating damage.

You have mentioned x-ray, which is enough to break bonds, but that's not the problem here. Your comment about heating is a little non-specific. There are different types of heating you can have, including microwave, IR, or UV (which burns moreso than heats).

You are correct that there is no reason to think that any of these types of radiation would affect the brain without affecting the skin or surrounding tissue.

Cell phones use the low microwave area of the spectrum... To be sure I got it all, lets use the generous range of 500MHz to 2GHz. (average probably just under 1GHz)

The heating I mentioned would be absorption heating in the same manner that a microwave oven works.

Hand held cell phones put out a maximum of about 1 Watt. Your head would absorb only a small fraction of that (if you absorbed much of it, the call could not go through).

1GHz is FAR below (7 orders of magnitude) where ionizing hazards begin. Even using the entire 1 Watt of power to heating your brain would not be significant unless a way was found to restrict the heating to a pretty small unit volume.

Hi all.

A recent study from an institution in South Australia presented pretty convincing evidence that radiation generated by mobile phones has no effect on the cancer rates or other disease rates of mice.

It was a pretty sophisticated experiment over a number of years designed to answer criticisms levelled at previous trials. I don't know all the details, but the exposure levels and times were specifically aimed at reproducing those humans would experience rather than just blasting them 24 hours a day. They had a range of different doses and exposed 1600 mice to these for one hour a day. During exposure, the mice were placed in tube that was housed on a wheel. Each day, the wheel would be rotated to the next position and the mouse would be exposed to a different dose. This went on for 2 years. Mice that died during the trial were replaced by a dummy wadding in the tube to answer any question of radiation not being absorbed by a mouse going on to affect nearby tubes.

I don't remember other details but it did seem a thorough study.

I am completely unconvinced about the 'triggering' Alzheimer's thing. They don't offer any explanation for this premise apart from 'dead brain cells' appearing.

I had to laugh at the following statement:

Quote:

They experimented on rats aged between 12 and 26 weeks. Their brains are regarded as being in the same stage of development as teenagers.

I have a teenaged brother and I have to say, rats are not anywhere near as cranky, careless and antisocial as he and his peers.

I agree that the findings warrant further investigation and should not yet cause alarm but as with all these news reports, I'm left with a lot of questions. No mention is made of sham control rats, the exposure levels and whether the experimental procedures themselves may have contributed to the findings (that is, do young rats develop these pathologies because someone picked them up every day or restrained them and so on). And yes, despite rat brains being scaled down models of human brains, skull density and shape is very different.

I'll keep using my mobile for the moment - I don't have that much to lose.

[neutrino_cannon]

Isn't cell phone radiation microwave, essentialy high frequency radio? What could that do besides cause a little heat, perhaps some ionization (which I assume would go to your hair, assuming you have any. This would seem to indicate that you're causing huge and irreperable damage yo your brain when you stick balloons to walls), and maybe a few damaged chemical bonds.

You might as well try to kill somebody with a smoke detector.

[scotth]

Quote:

Originally posted by neutrino_cannon
Isn't cell phone radiation microwave, essentialy high frequency radio? What could that do besides cause a little heat, perhaps some ionization

Or perhaps not. As mentioned earlier, it is 7 orders of magnitude lower frequency than is required to ionize.

There are also, of course, more effects from cell phone use than just cancer rate increase.

We tend to do stupid things while using our cell phones, especially driving.


I'd wager that years from now we will be told that there is evidence of increased cancer rates from cell phone use.

Right now, all the businesses don't wan't to hear that though.

[pgwenthold]

Quote:

Originally posted by Whodini
There are also, of course, more effects from cell phone use than just cancer rate increase.

We tend to do stupid things while using our cell phones, especially driving.

LOL!

"You are 1000 times more likely to die in a car wreck while talking on the cell phone than from phone-induced cancer."

[richardm]

I wonder how much of the worry about cellphones is due to the use of the word "Radiation"? I seem to recall that MRI scanner folks rapidly dropped the word "Nuclear" from their name when they realised the effect it was having on the public.

[The Don]

How about all that other stray EM radiation ? You'd think that if radio waves caused cancer we'd have a lot of sick ham radio operators by now (not that it would be a bad idea )

[Jon_in_london]

I think one possible mechanism is the fact that DNA polymerase relies on electromagnetic interactions to correctly recognise the bases hence strong EM raditation may disrupt DNA replication =>mutations =>cancer

[scotth]

Quote:

Originally posted by Jon_in_london
I think one possible mechanism is the fact that DNA polymerase relies on electromagnetic interactions to correctly recognise the bases hence strong EM raditation may disrupt DNA replication =>mutations =>cancer

Define the word strong....

1 Watt of 1GHz RF is not even in the ballpark.

[jj]

Quote:

Originally posted by Whodini
There are also, of course, more effects from cell phone use than just cancer rate increase.

We tend to do stupid things while using our cell phones, especially driving.


I'd wager that years from now we will be told that there is evidence of increased cancer rates from cell phone use.

Right now, all the businesses don't wan't to hear that though.

Check out "Drivers on the Phone" at www.twistedtunes.com.

As to cancer, well, life causes cancer. Perhaps we should just ban life?

If Cell Phones cause cancer, I'd be surprised if it wasn't the plasticizer in the case or something like that.

----
As to cancer, well, life causes cancer. Perhaps we should just ban life?
----


Cell phone use is optional.

cell phone --?--> cancer

life---something else---> cancer

, because there are many living things that do NOT get cancer.

[garys_2k]

And all those that got Alzheimers before cell phones were invented?

[Walter Wayne]

Quote:

Originally posted by scotth
2) Heating damage. You can damage a material by heating it enough. You have skin on your skull that would feel noticable pain if it was being heated enough to damage it. It would be odd to think that your brain might be heated to a greater degree than tissue closer to the source.

I don't know much about biological affects but heating is not necessarily greater on tissue closer to the source. Two things are going to affect the heating.

1) Power density incident
2) Lossiness of the material

For instance air is almost lossless at cell-phone frequencies, so we don't notice EM radiation heating up the air. Our tissue is lossy, so some heating occurs.

Question: What tissues in the body are more or less lossy in the human body? Skin, body, brain matter?

Walt

[jj]

Quote:

Originally posted by Whodini
----
As to cancer, well, life causes cancer. Perhaps we should just ban life?
----


Cell phone use is optional.

cell phone --?--> cancer

life---something else---> cancer

, because there are many living things that do NOT get cancer.

Many multicellular organisms? Really? Especially Mammals?

Do tell. Please. Evidence must follow, too.

Btw, is there a reason you didn't comment on the plasticizer issue? I doubt there is any, but it strikes me as more likely than anything else.

---
Many multicellular organisms? Really? Especially Mammals?

Do tell. Please. Evidence must follow, too.
----


I never said multicelluar, you did.

But more important, I said there are living things that do not get cancer. I do not have cancer. My father does not have cancer. This tree next to me doesn't have cancer. *Can* they have cancer? Yes.

Does life *cause* cancer? No (else every living thing would have or get cancer). There are confounding variables, like radiation, for example.


----
Btw, is there a reason you didn't comment on the plasticizer issue?
----


I don't know what plasticizer means.

[jj]

Quote:

Originally posted by Whodini
---

Does life *cause* cancer? No (else every living thing would have or get cancer). There are confounding variables, like radiation, for example.


----
Btw, is there a reason you didn't comment on the plasticizer issue?
----


I don't know what plasticizer means.

Neeeever miiiind.

[Jon_in_london]

Quote:

Originally posted by scotth


Define the word strong....

1 Watt of 1GHz RF is not even in the ballpark.

I dunno... It would be a relatively simple experiment to do though and the results would certainly be interesting.

[scotth]

Quote:

Originally posted by Jon_in_london


I dunno... It would be a relatively simple experiment to do though and the results would certainly be interesting.

So simple that it has been done.

[Jon_in_london]

Quote:

Originally posted by scotth


So simple that it has been done.

Oh yes? by whom? reference?

Quote:

Originally posted by Whodini
[b]
I never said multicelluar, you did.[b]

Unicellular organisms don't get cancer. So what else could you have meant?

Cheers,

[scotth]

Quote:

Originally posted by Jon_in_london


Oh yes? by whom? reference?

The threshold frequency of ionization has been established and re-established by physicists all over the world beginning shortly after Einstein wrote his little paper on the photoelectric effect that fathered quantum mechanics in the early 1900's. If you examine any EM spectrum chart that notes the ionization threshold, it will always be somewhere in the neighborhood of the visible light/ utraviolet light transition. 1GHz RF is 10^7 lower in freqency.

A little background on what this means. As you hopefully already know, visible light is a short section in the middle of the electromagnetic spectrum that we happen to be able to see. There is no difference between visible light, A.M. radio, or x-rays other than the frequency. It was discovered (and the whole field of quantum mechanics is built upon this principal and a couple other small assumptions) that energy delivered by a bit (photon) of light is proportional to its freqency. It takes a minimum amount of energy to disturb the chemical bonds between atoms and molecules. This minimum energy corresponds directly to a freqency. This frequency has a specific name attatched to it. It is called the ionizing threshold. This is exactly where you begin having the possibility of disturbing chemical bonds (technically, this is when you can begin knocking electrons loose... but the effect is the same) 1GHz is 10,000,000 times lower than this ionizing threshold.

Microwave can also be used to heat things. But then, the damage is done by the heat, not directly by the heating waves. Standing a few minutes in the sun, would be absolutely lethal if a cell phone is worrisome at all.

Now, let me ask. Can you jump the Grand Canyon on a bicycle? No? Have you ever done that experiment, specifically? No? How do you know, then? None the less, you do know. You know that at best you could jump 20, 30, lets say even 100 feet on a bicycle under the most ideal conditions. But, obviously the Grand Canyon is so much beyond that limit it can pretty well be dismissed out of hand. That is pretty much the situation when you look at the idea of a cell phone causing cancer and such from a physics point of view. You never did that specific experiment, but..... the relevant data is in hand.

[Jon_in_london]

Scotth, I wasnt refering to ionising radiation I was refering to radiation sufficient to cause disruption to DNA polymerase as it reads along its template strand.

Would cell-phone radiation be enough to affect hydrogen bonds and/or Van der Waals forces?

Of course I can jump the grand canyon- if I eat enough baked beans

[pgwenthold]

Quote:

Originally posted by Walter Wayne
I don't know much about biological affects but heating is not necessarily greater on tissue closer to the source. Two things are going to affect the heating.

1) Power density incident
2) Lossiness of the material

For instance air is almost lossless at cell-phone frequencies, so we don't notice EM radiation heating up the air.

"lossiness"?

Air doesn't heat up by most radiation because N2 and O2, 99% of air, do not absorb most incident radiation. Air does heat up when, for example, there is a lot of CO2 in it because CO2 absorbs in the low IR.

The air most certainly does heat up by absorbing deep UV though. IIRC, the cutoff is a little less than 200 nm. It's a good thing that air absorbs this, though, because that type of radiation would fry us pretty bad. Imagine a bad sunburn with little exposure.

Quote:

Our tissue is lossy, so some heating occurs.

Question: What tissues in the body are more or less lossy in the human body? Skin, body, brain matter?

There isn't much difference between them. Bone is significantly different, but that because it is crystalline salt. Skin and tissue are all organic, and the differences between them are trivial.

[BobM]

Quote:

Unicellular organisms don't get cancer. So what else could you have meant?

Are you sure? Maybe that's how multi-cell life started.

[scotth]

Quote:

Originally posted by Jon_in_london
Scotth, I wasnt refering to ionising radiation I was refering to radiation sufficient to cause disruption to DNA polymerase as it reads along its template strand.

Would cell-phone radiation be enough to affect hydrogen bonds and/or Van der Waals forces?

Of course I can jump the grand canyon- if I eat enough baked beans

DNA is made of matter. Quantum Electrodynamics is the study of the interaction between Light (all frequencies) and matter.

DNA does its stuff following all the known laws of chemistry. In a physics sense, there is nothing special about it.

What plausible mechanism would cause DNA, of all the arrangements of matter known to exist, to be disrupted chemically by photons of 10 million times lower energy than any other arrangement of matter know to exist?

[Jon_in_london]

Quote:

Originally posted by scotth


DNA is made of matter. Quantum Electrodynamics is the study of the interaction between Light (all frequencies) and matter.

DNA does its stuff following all the known laws of chemistry. In a physics sense, there is nothing special about it.

No ****

Quote:

What plausible mechanism would cause DNA, of all the arrangements of matter known to exist, to be disrupted chemically by photons of 10 million times lower energy than any other arrangement of matter know to exist?

Im not talking about actual damage to the DNA itself. I dont belive, nor have I ever belived that cell-phone radiation is sufficent to ionise let alone disrupt C-C covalent bonds

If you read my earlier posts you would see that the mechanism Im preposing has to do with the possible disruption of the weaker electromagnetic forces (h-bonds and Van der Waals) used by DNA polymerase to correctly replicate DNA.

Quote:

Originally posted by BobM
Are you sure? Maybe that's how multi-cell life started.

Cancer is defined as the uncontrolled growth of cells in a multi-cellular organism. Although it can be diagnosed at the cellular level, it is really a histological definition.

Cheers,

[BobM]

Oh.. so now you're just defining the possiblity right out of exisitence!

Quote:

Originally posted by BobM
Oh.. so now you're just defining the possiblity right out of exisitence!

Well, you know Doctors are God.

Cheers,

[JamesM]

Quote:

Originally posted by Jon_in_london
the mechanism Im preposing has to do with the possible disruption of the weaker electromagnetic forces (h-bonds and Van der Waals) used by DNA polymerase to correctly replicate DNA.

I doubt any of the following is much help, but in case you're interested in vague numbers...

Estimations of what an average bond strength is obviously vary, but for an H-bond, somewhere around 20 kJ/mol would be reasonable.

A van der Waals force would be more like 1-5 kJ/mol.

Compare this with a typical range of covalent bond strengths: 200-400 kJ/mol.

Clearly, an H-bond is about one order of magnitude weaker than a covalent bond, and a van der Waals attraction would be one order weaker than that.

As someone else has mentioned, you need ultraviolet radiation to cleave a covalent bond, which is six orders of magnitude more energetic than microwave radiation. So we're still missing 4 orders of magnitude with microwave radiation to dissociate van der Waals forces, and 5 orders of magnitude for H-bonds.

Those numbers for the bond strengths include the energy needed to separate the two bonding species back into their standard states, so it would require less energy to merely break the bond and leave the atoms in the same position. We're not talking orders of magnitude, though.

HTH.

[scotth]

Exactly the data I was looking for JamesM.

The only minor correction but still leaving the same conclusion:
1-5kJ is about 2 orders of magnitude under 200-400 kJ. It starts with 7 orders of magnitude short and would still be 5 orders instead of 4.

[JamesM]

Quote:

Originally posted by scotth

The only minor correction but still leaving the same conclusion:

Oh yes, when discussing orders of magnitude I made a complete nonsense of it by typing 'van der Waals' when I meant 'H-bond' and vice versa. Whoops. Well done for spotting the - ahem - deliberate mistake.

[Soapy Sam]

...So the world is safe for cellphone users.

Blast.

Perhaps the experimenters are confusing cause and effect. Maybe it's just that people with defective neural hardware are major users of cellphones.
Given the intellectual content of most of the mobile phone calls I have been forced to overhear by inconsiderate people in trains and other public places, I tend to lean strongly toward this theory myself.

[kittynh]

If it weren't for cell phones we wouldn't kind of where to look for the bodies in the morning....
yes, it's that time of year in NH! Time for people to climb the White Mountains and when you get lost and stuck overnight...and figure out your NOrth Face Parka being rated -30 below doesn't mean you aren't gonna die fast...you pull out your cell phone!
Sorry Charlie...a vague, "of course I don't know where I am, I'm in a blizzard!"
We are sorry to lose the tourists this way....

[Soapy Sam]

Aye. They're still at it in the Grampians too.
Still, it gives the cruise missiles something to zero in on...

[Jon_in_london]

Quote:

Originally posted by JamesM
Those numbers for the bond strengths include the energy needed to separate the two bonding species back into their standard states, so it would require less energy to merely break the bond and leave the atoms in the same position. We're not talking orders of magnitude, though.

HTH.

*disclaimer* Im not a physicist/pjysical chemist but a molecular biologist.

It seems from what you have posted, that cell-phone type radiation would be insufficent to disrupt Van der Waals and H-bonds. I would therefore think its highly improbable that cell-phone use could disrupt the action of DNA polymerase- negating my proposed mechanism for carcinogenicity.

However, I would still like to see this proven experimentally although I would expect negative results.