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News Cell phones causing cancer goes national

  1. Dec 20, 2009 #1

    Pengwuino

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    http://www.msnbc.msn.com/id/34502456/ns/health-cancer/

    Maybe this is the excuse I need to tell people to stop calling me with meaningless dribble.
     
  2. jcsd
  3. Dec 20, 2009 #2
    I'm pretty sure many scientific studies have done that have shown that cell phones do not lead to increase risk of anything... do these states also want to put a ban on microwave ovens?
     
  4. Dec 20, 2009 #3
    http://content.nejm.org/cgi/reprint/344/2/79.pdf

    http://www.bmj.com/cgi/reprint/332/7546/883

    Here's an article from Japan:
    http://www.nature.com/bjc/journal/v98/n3/pdf/6604214a.pdf
    However it's been suggested that the method used as 'recall' maybe not be true. That is they have dismissed a certain amount of giloma cases to people looking for a cause to their condition (i.e. they already believe the cell-phone caused it so they are purposely making it seem like that is the case in the interviews).

    I hate when politics goes against the science available and off of personal bias which is clear in this case:
    From your article, it shows that this Rep. has decided against available science.

    I mean like this case in general doesn't really have huge effects, it's just the principle involved. To ignore the evidence and try to create policy off of your beliefs instead of what's really out there. Of course the science may conclude that long-term exposure to cell-phone radiation increases cancer/tumours... but like how long are we talking? If after 100 years it is still concluded that that term of time of radiation exposure does not increase risk are people going to say maybe it's longer??? Humans do only have a finite lifespan.
     
  5. Dec 20, 2009 #4

    cristo

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    From what I read in the article, the representative does not want to ban anything, but instead wants mobile phones to carry warnings that their use can cause brain tumours. I'm pretty sure microwaves carry warnings anyway, as a precaution, and so I don't see this as being too controversial a measure.
     
  6. Dec 20, 2009 #5
    I never said anything about banning cell phones. Are you going to try to tell me that a mobile phone radiation is comparative to a microwave? What I'm saying is more along the lines of: If this rep wants cell phones to carry warning for cancer I can only imagine their view of microwaves.

    EDIT: I fixed a typo.
     
    Last edited: Dec 20, 2009
  7. Dec 20, 2009 #6

    mgb_phys

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    it depends, does this mean a whole bunch of lawsuits as people hope to get a few $ to pay for their treatment, or is it a precautionary measure by the makers to forestall any future court cases - since, like cigarettes, the users have been warned?
     
  8. Dec 20, 2009 #7
    Do they still cause cancer when the bluetooth short-range device is on your ear and it's the main receiver/transmitter unit that's on your belt?

    Perhaps the warning should mention something about appendectical cancer.
     
  9. Dec 20, 2009 #8

    mgb_phys

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    There is no evidence that they cause cancer at all

    Of course since the bluetooth also uses 2.4GHz microwaves and since there is no evidence that bluetooth causes cancer then the bluetooth must presumably also carry the same warning.
     
  10. Dec 20, 2009 #9
    Along with many cordless home phones.
     
  11. Dec 20, 2009 #10
    Not only have all of the large scale studies I have read (including one recently completed in Scandinavia) show no correlation between cell phones and brain tumors, but even a correlation is not really sufficient evidence without a reasonable physical theory to explain how cellular EM frequencies might cause cancer.

    Like Carl Sagan wrote, extraordinary claims require extraordinary evidence. There is not even ordinary evidence in this case.
     
  12. Dec 20, 2009 #11
    It means that cell phone companies will be legally required to admit responsibility for something which they are not responsible for. Slap a warning label on your product that says it may cause cancer then try going to court and explaining why you have such a warning on your product when you hold that there is no such risk.
     
  13. Dec 20, 2009 #12
    You would have a greater chance of getting a brain tumor from a dark matter particle than RF radiation.

    Cell phones don't transmit 24/7. It is only when you speak, the cell phone starts to transmit in short bursts of RF. When the sound level is low enough, the transmitter is not transmitting - for purposes of saving power.

    Also, the cell phone antenna is pretty much omni directional, meaning most of the RF power gets transmitted into the air, and only a small percentage goes through your head. In contrast, a microwave oven focuses intense RF energy on a closed cavity, where 100% of radiation can get absorbed by food.

    I don't know what they are warning against but themselves.
     
  14. Dec 21, 2009 #13
    We shouldn't forget the one major effect that this and other similar regulations have: They result in people habitually ignoring printed warnings, similar to the story of the boy who cried wolf.
     
  15. Dec 21, 2009 #14

    mgb_phys

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    Especially in California, every office that contains laser toner or nail varnish now has one of those "contains a substance known to cause cancer" warnings.
    I don't know what warnings you would put up if it really did contain something dangerous.
     
  16. Dec 21, 2009 #15
    Wow this is very true. Never even thought about it this way, lol. When there is an important warning it better come with sirens and flashing pointers.
     
  17. Dec 21, 2009 #16

    BobG

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    Microwave ovens use a narrow range of frequencies in an oscillator. The narrow range of frequencies used are absorbed by water, fat, and sugars. Using those same frequencies on your own body would excite and cook the parts of your body that contain water, fat, and sugar.

    Your cell phone probably uses spread spectrum transmissions (it definitely does if its 3G). The power of your transmission is spread over an extremely large range of frequencies and then recompressed into a narrow range of frequencies when received.

    The amount of power for any given frequency is very low and isn't going to have an effect.

    If you're still using an analog cell phone, or your phone uses frequency hopping, I guess there could be a possibility of that frequency having some sort of effect on your body. Having the same range of frequencies absorbed by your head all the time is going to be worse than a pulse that's constantly changing frequencies, but the pulse has interfered with other devices the person may have, such as pacemakers and hearing aids (or else it's included as a generic warning for any device that transmits RF energy).

    And, while waht is right that cell phones don't transmit continuously, they do transmit frequently so the cell phone network will know where the phone is. Any time your phone indicates it has a signal, it means your phone has transmitted its ID and location to the network and the network now knows what cell you're in so it can route any incoming calls to you.

    I'm pretty sure the phone transmits less when it has a signal than when it's lost a signal. At least, if you're in an area where the signal is intermittent, the battery seems to die a lot sooner (this was a problem when I visited my parents after Baton Rouge's fall 2008 hurricane).
     
    Last edited: Dec 21, 2009
  18. Dec 21, 2009 #17
    Yeah, the stronger the single the less power put behind the frequency. When you have low reception your phone uses more power.
     
  19. Dec 21, 2009 #18

    Integral

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    Does anyone have figures as to how far into the head the the low power RF penetrates? The head is mostly water afterall.
     
  20. Dec 21, 2009 #19

    mgb_phys

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    From C.C. Johnson & A.W. Guy, “Nonionizing electromagnetic wave effects in biological materials and systems,” Proc. IEEE, 1972.

    http://www.siddeutsch.org/table7-2.jpg
     
    Last edited by a moderator: Apr 24, 2017
  21. Dec 21, 2009 #20

    BobG

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    I think it penetrates clear through a human head. At least, having my friend stand between my radio and Cheyenne Mountain where all the radio station towers are doesn't seem to affect my reception.

    Seeing as how the signal could bounce off of various objects, that's not a conclusive test. In fact, eliminating a few routes for multipathing could improve reception.
     
  22. Dec 21, 2009 #21

    mgb_phys

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    But only upto a limit, 2Watt at 800/900MHz and 1W at 1800/1900MHz
    The base station and phone communicate their received power levels (a digital version of reading you loud and clear) and negotiate the minimum power, mainly to save battery life.

    On GSM (different to CDMA) especially in cities with crowded cells they also use a 1:8 time division multiplexing as well so even in a call they are only transmitting 1/8 of the time.
     
  23. Dec 21, 2009 #22

    Astronuc

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    No, just a warning not to hold the microwave too close to one's head while using it. :biggrin:
     
  24. Dec 21, 2009 #23

    mgb_phys

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    This has really slowed down my web browsing - but my hands are really clean.

    backmouse.jpg
     
  25. Dec 21, 2009 #24
    In former lab days I used to play around with spectrum analyzer alot, and often checked up on my cell phone.

    I never actually caught a spike when the phone was idle. Perhaps it sends updates, but longer in time intervals. And when you change your location, the cell phone will pick up a beacon from a different tower and then send updates to the network on its whereabouts.

    But when dialing, I used to get very erratic, spread-spectrum short bursts of RF around 1.8 GHz, that's a 16 cm line. The power levels were less than 10 dBm, or 10 mW picked up with a short whip antenna wrapped around the phone.

    When you are silent, the phone doesn't transmit. Only when sound level is high enough, it starts transmitting. So if you have a conversation and speak with 300 words, it will transmit about 300 times.
     
  26. Dec 21, 2009 #25

    mgb_phys

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    A GSM phone doesn't initiate a conversation with the base station, if there were a lot of phones in a cell this would tie up all the channels even if no one was making a call.
    The base station periodically sends out an update message to all phones in the cell, if any phone discovers it has newly arrived in that cell (eg turning a phone on after a flight) it will reply. But a phone which is still in the same cell as it was on the last update doesn't need to reply, the base station assumes it is still there and will only try and contact it when it has a call.
    Presumably there is some backup mechanism for the phone to resync if has somehow got forgotten about but I never had to get that deep into GSM

    GSM uses a predictive coding algorithm so if you go silent it doesn't need to send anything. When it's sending voice it also chops the channel into 8 sub channels and only sends compressed ata for about 4ms then waits for 7 * 4ms, this way you can get 8 calls in the same bandwidth without really noticing any break in the speech.
     
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