Medical How many cellular phone devices does it take to burn flesh?

[Encarta]

I couldn't think of a better category to introduce this. If anyone has a better idea as to where I should categorize this, please go ahead and suggest.

So, the question was inspired by the popular notion that microwaves emitted by cell phones can cause cancer. This view has been popular with the media for quite some time, and in turn, the public has suffered.
Well, to continue the background leading to my topic question, cell phones cannot cause cancer since microwaves have frequencies that are well below the threshold frequency needed to destroy DNA strands, which in turn cause cancer.
It is also obvious and reflects most of our experiences that cell phones cannot burn us either with their low intensity radiation.

But considering microwave ovens, even though it does not give you cancer, clearly putting a hand inside such an oven burns it.

Second, and finally
I was wondering, how to go on calculating the number of cell phones that would be required to start burning human flesh? Assuming, say, a piece of meat was to be brought to physical contact with various cell phones...

Thank you.

 

[zhermes]

Well, to continue the background leading to my topic question, cell phones cannot cause cancer since microwaves have frequencies that are well below the threshold frequency needed to destroy DNA strands, which in turn cause cancer.

While I tend to agree that cell phones are (virtually) harmless, you shouldn't be so quick to dismiss the possibility. So far, studies have been noticeably inconclusive in either direction.

Also, your logic is somewhat faulty: while microwave radiation is non-ionizing (the main danger for cancer), that doesn't mean it can't damage DNA. I can't find the particular article, but large complex biomolecules can be highly disrupted and destroyed by even non-ionizing radiation. Not only could this effect DNA directly, but damaged versions of the myriad RNA and protein which interacts with DNA could lead to mutations.

I was wondering, how to go on calculating the number of cell phones that would be required to start burning human flesh? Assuming, say, a piece of meat was to be brought to physical contact with various cell phones...

A good place to start would be to assume that the power required is about what a microwave puts out. Then find out how much power a cell phone puts out, and you can make a rough approximation---you won't be able to get a result more accurate than about an order of magnitude, so don't bother worrying about the details (e.g. energy distribution pattern of cell-phone antennae, etc etc).

 

[skeptic2]

So far, studies have been noticeably inconclusive in either direction.

While there are many studies claiming to show a link between cell phones and brain cancer, I have not heard of one that is reputable or stands up to scrutiny. The reputable studies have been so conclusive the FCC no longer accepts cell radiation danger as a reason to deny a cell tower installation.

Furthermore, while during the years from 1990 to 2002 the use of cell phones skyrocketed particularly those held against the head, during those same years the incidence of brain cancer decreased slightly.
http://www.cancer.gov/cancertopics/factsheet/risk/brain-tumor-study

From 1990 to 2002, the overall age-adjusted incidence rates for brain cancer decreased slightly; from 7.0 cases to 6.4 cases for every 100,000 persons in the United States. The mortality rate from 1990 to 2002 also decreased slightly; from 4.9 deaths to 4.5 for every 100,000 persons in the United States.

Also, your logic is somewhat faulty: while microwave radiation is non-ionizing (the main danger for cancer), that doesn't mean it can't damage DNA.

Even table salt can damage DNA.
http://ajprenal.physiology.org/cgi/reprint/00060.2003v1.pdf

Abstract
High NaCl causes DNA double-strand breaks and cell cycle arrest, but the mechanism of its genotoxicity has been unclear. In this study we describe a novel mechanism that contributes to this genotoxicity.

 

[zhermes]

the FCC no longer accepts cell radiation danger as a reason to deny a cell tower installation.

1) How many carcinogens has the FCC allowed at some time or place?
2) Which direction do you think external factors bias the FCC?
3) Cell towers are very different from cell phones

Furthermore, while during the years from 1990 to 2002 the use of cell phones skyrocketed particularly those held against the head, during those same years the incidence of brain cancer decreased slightly.

This data is meaningless without comparison between controls and the standard fluctuations. Additionally, the time frame is simply too short to be accurate---if you look at 20 yr olds who smoke, oddly enough, you won't find many with cancer within 10 years.

Even table salt can damage DNA.

What's your point? Thank you for agreeing with me?

You're making very poor and unconvincing arguments for an opinion I already agree with, as I said above. Additionally, this has little to do with the OP.

 

[CRGreathouse]

I was wondering, how to go on calculating the number of cell phones that would be required to start burning human flesh? Assuming, say, a piece of meat was to be brought to physical contact with various cell phones...

The maximal absorption by human tissue of microwaves is around -20 dB at 800 MHz. Assuming high-powered 1 W cell phones operating at that frequency, it would take 1000 W / (1 W * 10^(-20 / 10)) = 100,000 cell phones to equal the power of a cheap 1000 W microwave oven, assuming that you were able to focus them over an area similar to the size of a microwave oven (duh).

But as long as you have that focusing lens, you should be able to heat tissue slightly (enough to help keep you warm) with as few as a few thousand cell phones.

Without a focusing lens, it's unlikely to be feasible. The worst case without a focusing lens is that you're surrounded with a sphere of cell phones; those in direct contact give you one-half the dose from the focused version (because half points away from you); as the cell phones get further away they give increasingly small fractions of their dose in your direction. Assuming that cell phones are very small and absorb no cell phone radiation*, you might be able to get away with as few as half a million cell phones; more likely you'd need ten times as many.

If, instead of a lens, you put the person in a small reflective box, it becomes much easier. Ten thousand cell phones suffice to cook the person; 500 would warm her about 0.1 degrees C per minute (depending, of course, on her weight, and assuming the thermal capacity of the human body is 1 calorie, like water).

* Obviously this can't be true, or they would have no reception!

 

[tracydimarco]

Only one - I'm sure there's a flamethrower app for the iphone, right? :)

 

[eachus]

But considering microwave ovens, even though it does not give you cancer, clearly putting a hand inside such an oven burns it.

Do NOT try that experiment at home--or anywhere else. The frequency used in microwave ovens is chosen to minimize cooking times. It resonates with OH bonds in lots of chemicals found in your body and causes them to break. The toxicity of the fragments will kill you way short of any cooking.

Second, and finally
I was wondering, how to go on calculating the number of cell phones that would be required to start burning human flesh? Assuming, say, a piece of meat was to be brought to physical contact with various cell phones...

You can't get there from here. Well, unless you live in an area which still has analog cell phone service only. Digital cell phones radiate much less power when you are talking, and most radiate nothing if not in use to prolong battery life.

And that was the silly thing about all those cell phone and cancer studies. It may have been the case that analog cell phones were associated with increased cancer risk, but the studies done did not differentiate between analog and digital service. Some retrospective looks at the data showed that there might have been a problem with analog phones--but there is no ethical way to do a study of that today. (We want you to use this free analog only cell phone with no limit on minutes. You will get poorer phone service, and we are hoping you get brain cancer. Right!)

Finally forget this as a red herring, and concentrate on blowing the whistle on the TSA. They did lots of selling on the advantages of T-ray machines, then installed a mixture of T-ray and X-ray backscatter machines. The T-ray machines are much less of a radiation hazard than the flight you are about to take. But unless it is a long flight, you will get more of a radiation dose from an X-ray backscatter machine. Loss of privacy is one thing, but adding an extra radiation dose... (I don't know how to finish that without expletives.)

 

[PhysDrew]

It actually depends on whether or not you are married. If not, about 100 000. If you are married and your wife catches you texting some other women, then only one, since she will burn your flesh more than any known force in the universe
;)