If you can hear me now, you might be in trouble

Photo courtesy of Ed Yourton. http://www.flickr.com/photos/yourdon/3754271881/

California is one of many states that bans talking or texting on a handheld device while driving. It's a national problem. In 2009, more than 5,000 people were killed on U.S. roads and about 450,000 were injured due because of so-called "distracted" driving.

But when it comes to cell phone use in general, there could be greater danger – many people believe cell phones cause cancer.

Over the last year, a group of researchers at the World Health Organization took a look at dozens of studies exploring that link. They concluded that cell phones are ”possibly carcinogenic.”

The WHO has labeled more than 250 things as “possibly carcinogenic,” including gasoline fumes, some kind of pickled vegetables, and coffee.

If you're confused, well, the WHO is probably confused, too. Of the six studies they looked at, the results were all over the place. The biggest and longest study the group looked at is called Interphone. It took 10 years of data from 10 countries in Europe, as well as Canada, Israel and Japan. And the conclusions it came to are completely inconsistent.

For heavy cell phone users – that means people who talked on a cell phone at least 30 minutes a day for 10 years – it found an increased incidence of brain tumors. But that rate didn’t hold for people who spent less than half-an-hour talking on their cell phones each day. In fact, the research might even suggest that the least chatty cell phone users were less likely to end up with brain tumors than people who spent their time on land lines.

And there’s more: A Swedish study found more brain tumors in all cell phone users compared with people who never used cell phones. But there’s a Danish study that found cell phone users developed brain tumors at the the national average. So, “possibly carcinogenic.” Which leaves us wondering: What do we need to know about cell phones and the radiation they emit?

That’s the question we asked KALW’s Christopher Connelly to take on in a segment we call “Brain Vitamin.”

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CHRIS CONNELLY: So here’s what we know – cell phones emit radiation, and that has people concerned. But not all radiation is the same, and it doesn’t all have the same effect.

The type of radiation cell phones emit is at the microwave level. Its wavelength is a little shorter, and a little more powerful, than a radio wave. Cell phones, basically, are like little radios. And just like a radio, the key part that makes them work is the antenna.

MIKE MARTIN: So an antenna basically is just a metal rod and you can get electrons to move up and down it.

Mike Martin is a physicist at Lawrence Berkeley National Laboratory.

MARTIN: That will create light that goes out from that antenna.

Well, probably not the light you’re thinking of. Light is jargon that physicists like Mike Martin use when talking about the whole spectrum of electromagnetic waves or radiation. Visible light is part of that spectrum, but it’s only a tiny part of the whole light spectrum. So radio waves are light, and X-rays are light, and microwaves are light, and the rainbow is light, and so on. They all emit some degree of radiation, measured by the frequency of the waves.

MARTIN: So a radio station, right? The typical frequencies they use are up in the 90, 100 megahertz range. So, in this case 91.7 megahertz...

That’s us, KALW – we broadcast at 91.7 megahertz.

MARTIN: That means 91.7 million cycles per second, so million up and down of the electric field per second, or the electron moving up and down the antenna.

So, you’ve got an antenna sending a signal – that’s called broadcasting – and on the other end, you’ve got a radio with an antenna and a tuner that's picking up that frequency. The tuner decodes that information and it reveals it to you as the voice that’s coming off of the radio.

And voila, you can hear me now. My voice, being sent out from our transmitters on waves about 10 feet long that zip around cars and trees and buildings at 91.7 million cycles per second.

This kind of electromagnetic radiation is all around us, but scientists are not terribly concerned about radio waves causing health problems. We’ve been pumping them out in droves for decades, and they’re usually transmitted from towers that are pretty far from where people live.

Cell phones, which you can think of as small microwave radio transmitters that you hold right up against your head – those are new. And, almost since their inception, there’s been debate about what effect, if any, they have on your brain, and specifically, if they can cause cancer.

Pretty much everyone says that we need more research, because the research taken together, is largely inconclusive. That’s what the FCC says, and the FDA, along with the American Cancer Society and the National Cancer Institute. The majority of scientists in this country, at least, say that there is no scientific link because it’s just not possible for cell phone radiation to cause cancer.

For his part, physicist Mike Martin says there’s no measurable effect. 

MARTIN: And so if there’s no measurable effect, then that means that there’s no effect that I can see. So that means studies that have looked over decades for cancer or any other increases of diseases don’t show any effect that we can really correlate to the fact that a person had a cell phone or not.

Here’s why: Remember that radio waves are transmitted at about a hundred megahertz or so? Martin says the radiation from cell phones – the light – is about 10 times higher frequency, so 10 times faster, 10 times more powerful. But even at that rate, cell phones emit radiation that still has pretty long wavelengths. So, they don’t pack enough energy to mess up your cells and cause cancer.

MARTIN: There’s this thing called the ionization threshold.

The ionization threshold. We’ve known about it for a while, actually. It’s the idea that won Albert Einstein his Nobel Prize in 1921.

MARTIN: It's the energy it takes to create an ion.

And it’s the key to why most scientists think cell phone radiation is actually safe.

An ion is a charged particle. Atoms are neutral, so you can think of an ion as an atom that’s missing an electron. So it has a positive charge – it’s not neutral anymore. Electrons make the chemical bonds that hold atoms together in a molecule. So, if you have an energy that’s high enough to strip an electron all the way off of an atom – called ionizing the atom – you can change the chemical structure of a molecule, and that can be really bad.

MARTIN: If that molecule happens to be one of your DNA molecules, then that can break that DNA. Now if it happens to break in just the wrong way, then you can actually change the cell that that DNA is in and do something like turn on a cancerous mechanism. So you can actually create cancer.

The type of radiation we’re talking about here has a very short wavelength, down in the nanometers – that’s a millionth of a millimeter – and it includes things way up on the light spectrum, like X-rays. But the light coming from your cell phone? It is nowhere near as powerful.

MARTIN: Cell phones are a full million times less energy than the ionization threshold.

And here’s the thing: Anything above the ionizing threshold – bad news. But anything below – no biological impact.

MARTIN: Because this threshold is really a hard threshold. If you have any energy less than it takes to strip off an electron, you don’t strip off an electron, you don’t break a bond.

So cell phones emit non-ionizing radiation. So they can’t cause cancer, right?

LLOYD MORGAN: The first part’s true. The second part’s not.

Lloyd Morgan is a Senior Research Fellow with the Environmental Health Trust.

MORGAN: There’s no way that cell phone radiation can directly break DNA bonds. It doesn’t have the energy. But that it can’t cause cancer is the fallacy.

Morgan isn’t your typical cell phone researcher. He trained as an electrical engineer. And one day, he suffered a massive seizure.

MORGAN: It was Friday afternoon, April 28th, 1995; a date I will not forget.

When he woke up from the seizure, he was told that he had a large tumor in the lining of his brain.

MORGAN: This thing was about the size of a large peach. I talked to my neurosurgeon after he could operate – you can't operate immediately because this thing is swelling. And I say, "Why did I get this thing?" And he said, "Perhaps electromagnetic fields."

After the doctors removed his tumor, Morgan found himself with lots of time and a vested interest in electromagnetic radiation and brain tumors.

MORGAN: And it took me four months before I could go back to work. But I had already started looking at science papers, and stuff. So it changed the very direction of my life. Another way of putting it is, I got a second life.

Morgan started reading all of the studies he could find on the health effects of electromagnetic radiation, and he started going to conferences across the country – right about the same time that cell phones were gaining popularity. And he became increasingly concerned.

MORGAN: I didn't talk publicly about this for a long time. I had to be really confident in myself that I know what I was talking about. Even when I went to these science meetings, it was several years before I would even go to a microphone and ask questions. I'm really self-taught in epidemiology.

In 2000, Morgan started focusing full-time on cell phones and cancer, joining a small but vocal faction that says cell phones actually are causing harm. He’s been an advocate for more unbiased research independent of industry – which he thinks is biased – because he says a rash of brain tumors from cell phones is coming.

MORGAN: Whenever industry does studies – this is well known – the chances of their finding some problem with the product that they're studying is very small compared to people who are not financially invested in the outcome. So any research to be done needs to be done by independent scientists.

Morgan says that even non-ionizing radiation from cell phones can do damage. It increases free radicals, which are unstable particles that can build up in cells and ultimately damage DNA and proteins. And, he says, there’s also:

MORGAN: Resonance – when you blow very lightly across a beer bottle.

The basic idea here is that waves will resonate at the same frequencies as the chemical bonds in the cells, jostling and jarring them in a bad way, maybe break a DNA strand. Or they’ll resonate at the same frequency as a chemical reaction, causing all kinds of problems.

According to Morgan, there are other possible cancer-causing mechanisms, but ultimately, the most important thing is not how they are caused.

MORGAN: In science, data is gospel, not ideas, not mechanisms. It’s almost an irrelevant discussion to say it can’t happen. If you have overwhelming data, if you do experiments, those are the results that you get, that’s what's called truth in science.

Morgan says the truth is there – more brain tumors. Acoustic neuromas. Eye cancer. Testicular cancer.

MORGAN: Yes, if you keep a cell phone in your left pocket, it’s your left testicle. If you prefer to have your right testicle to have cancer, you place it in your right pocket.

And, Morgan says, it’s not just cancer. He says studies implicate cell phones in insomnia, breakdowns in the blood-brain barrier, and sterility.

MORGAN: There's overwhelming data that shows that it can. And really, what matters is data.

But as you consider that, you also need to keep this in mind: the data, the studies that Morgan cites, they’re only part of the hundreds of research studies that have been done on the matter. A number of studies – most of them, in fact – found no conclusive connection.

Ultimately, it’s still early. It can take 30 plus years for solid tumors to develop, and cell phones haven’t been in widespread use for nearly that long.

In the last 15 years or so, they’ve gone from a fad for the super-rich to an indispensable tool for modern life. And now, there are more than 300 million cell phone subscriptions in the U.S. – that almost exactly matches the nation’s population.

So we’ve opened up Pandora’s Box, and found that it fits easily in our pocket. We’ve already determined that it can transform our ability to communicate, to inform ourselves, and to stay connected. The potentially darker sides, if they actually exist, will take longer to definitively reveal themselves.

In Berkeley, I’m Christopher Connelly for Crosscurrents.

This story originally aired on July 21, 2011.

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If you want to reduce your exposure to cell phone radiation, there are a few simple things you can do. Mostly, you should keep it away from your body. Even the cell phone companies recommend that you keep the phone about an inch from your head (look at the safety warnings that came with your phone).

  • You can use a wired headset, talk on speakerphone, or text.
  • And don’t put it in your pocket or bra. They may be easy places to hang on to a cell phone, but it’s another way of exposing sensitive areas to radiation.
  • If you let your kid play games on your cell phone or iPad, put it on airplane mode so it’s not sending a signal.
  • Last, don’t go to sleep with the cell phone on a bedside table next to your head.