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  • A lot of people worry that their cell phone will give them cancer, which isn’t all that

  • surprising.

  • I mean, youre holding a device that emits radiation right next to your brain! Terrible

  • idea, right?

  • Wellno.

  • Some kinds of radiation /can/ damage DNA, which can then lead to cancer. But your cell

  • phone doesn’t give off that kind of radiation.

  • And even if there /was/ a way that cell phone radiation could hurt you, studies have shown

  • that it doesn’t.

  • Cell phones communicate with cell towers using a form of radiation known as radiofrequency,

  • or RF, radiation.

  • The wordradiationis just in there because it’s a type of energy on the electromagnetic

  • spectrum.

  • The spectrum goes from low energy at one end to high energy at the other. Radio and microwaves

  • are near the low end. Gamma rays and X-rays are near the high end.

  • It can help to think of electromagnetic radiation as a wave, with a certain frequency based

  • on its energy.

  • The higher the energy, the higher the frequency.

  • When an electromagnetic wave hits an atom, it transfers some energy to that atom. When

  • the wave has a high enough frequency -- meaning, it has lots of energy -- it can transfer enough

  • energy to the atom to knock out an electron.

  • Electromagnetic energy that can knock out electrons is called ionizing radiation, and

  • it can break chemical bonds in your cells and damage your DNA.

  • In other words, it’s the cancer-causing kind.

  • When electromagnetic energy /doesn’t/ have a high enough frequency to break chemical

  • bonds, it’s called non-ionizing radiation.

  • If non-ionizing radiation hits an atom, it isn’t going to be able to knock out an electron.

  • So it can’t damage cells, and it can’t cause cancer.

  • It doesn’t matter how strong the beam of radiation is. Its ability to knock out electrons

  • only depends on its frequency, which isn’t affected by the intensity of the radiation.

  • It’s like how, no matter how powerful your microwave is, it’s never going to start

  • emitting infrared radiation -- which would be the next level up in frequency.

  • The cutoff between ionizing and non-ionizing radiation is somewhere in the ultraviolet

  • range. That’s above visible light in frequency, and wayyyy above the radio waves that cell

  • phones use.

  • Which is why, based on what we know about physics and biology, there’s nothing cell

  • phones do that can give you cancer.

  • However, doctors and scientists do take the potential health risks of cell phones seriously, and

  • a lot of studies have been done to see if there’s a link between cell phones and cancer.

  • Sometimes, these studies do find what /sounds/ like a relationship between cell phones and

  • cancer -- at least, at first.

  • For example, one study of a million women in the UK found what seemed to be a weak link

  • to a tumor called an acoustic neuroma [nur-OH-ma], a benign tumor in the nerve that leads from

  • the ear to the brain.

  • More frequent cell phone use was correlated with a higher risk of getting this tumor.

  • But the study followed the subjects for seven years. If there actually was a connection

  • between this tumor and cell phone use, you’d expect more people to develop the tumor

  • as they were exposed to more radiation over time.

  • But the numbers didn’t go up.

  • Based on that, and the fact that other large studies haven’t found the same connection,

  • the authors of the study concluded that it was a statistical fluke.

  • Another large study from the World Health Organization found an increase in glioma -- a

  • type of nerve cell tumor that’s responsible for most cases of malignant brain cancer -- among

  • the 10% most frequent cell phone users.

  • But there were problems with that study:

  • They collected data by having people report their own cell phone use, and people tend

  • to remember incorrectly.

  • Plus, people who used their cell phone infrequently had a lower risk of glioma than

  • people who didn’t use them at all.

  • If cell phone radiation was causing the tumors, that wouldn’t make any sense.

  • And the vast majority of other studies have found no evidence that cell phones can cause

  • tumors.

  • There’s also the fact that if cell phones were causing some kinds of cancer, we’d

  • be seeing the rates of those cancers go up.

  • I mean, something like 5 billion people use cell phones, and theyve been commercially

  • available since the mid-1980s. That’s long enough for cancer to start showing up, even

  • if it takes a few decades to develop.

  • That’s exactly what happened after cigarettes started being mass-produced. Lung cancer used

  • to be pretty rare, but when smoking cigarettes started to become more popular, lung cancer

  • rates went way up.

  • There just isn’t any sign of this when it comes to cell phones. Both the number of people

  • who get brain cancer, and the number of people who die from it, is holding steady even as

  • cell phone use skyrockets.

  • So go ahead. Make as many phone calls as you want.

  • Thanks for watching this episode of SciShow, which was brought to you by our patrons on

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携帯電話はがんの原因になる? (Do Cell Phones Cause Cancer?)

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    Helen に公開 2021 年 01 月 14 日
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