This is old news at this point, but still worth mentioning on a cancer blog: Cell phones might possibly cause cancer. From one of the billion articles that pop up when you Google “cell phones cancer”:
Radiation from cell phones can possibly cause cancer, according to the World Health Organization. The agency now lists mobile phone use in the same "carcinogenic hazard" category as lead, engine exhaust and chloroform.
Before its announcement Tuesday, WHO had assured consumers that no adverse health effects had been established.
A team of 31 scientists from 14 countries, including the United States, made the decision after reviewing peer-reviewed studies on cell phone safety. The team found enough evidence to categorize personal exposure as "possibly carcinogenic to humans."
Like many “stories” that explode into a thousand articles all at once, this one is complete bull. Or at least, mostly bull. I can’t say things better than others have already said them, so I’ll let my little homies ride on you. Starting with the American Cancer Society:
Unfortunately, drawing broad and sweeping conclusions based on a press release and a news conference leaves many of us wondering just what the evidence shows that led to the conclusion announced today that "radiofrequency electromagnetic fields" may be possibly cause cancer in people…
Why has it been so difficult to answer the question about cell-phone use and cancer?
It turns out that the simple answer is that the research hasn't clearly pointed in one direction of another. In addition, there are so many variables that can confound these types of studies such that a clear conclusion isn't evident. So we end up in a quagmire of scientific opinion instead of the crystal clear direction we would prefer.
Mobile phones may cause cancer, experts say
But I can’t find anything in the article that shows a link, much less justification for the word cause. The article does note that numerous prior studies have failed to find a link between cell phones and brain cancer. It also points out that studies are limited by the sheer number of people who use cell phones. It mentions one study that “hinted” at a link between cell phones and one particularly rare form of brain cancer, but noted that the study required researchers to ask participants about cell phone use from years ago. The article also explains that cell phones haven’t been around long enough to draw any conclusions about long-term effects.
There are a lot of problems with the claim that cell phones cause cancer, not the least of which is that the science and epidemiology just don't support it. In particular, the INTERPHONE study, whose results were reported last year, showed no evidence of a link between cell phone use and glioblastoma or meningioma. In fact, to me the decision by WHO is exceedingly puzzling because, if anything, over the last several years the evidence has been trending more and more towards being inconsistent with with a link between cell phone use and brain cancer--or health problems of any kind, other than getting into car crashes because of texting or talking while driving. I note that the INTERPHONE study relied on a dubious subgroup analysis in order to find that there was a 40% increased risk of glioma in the very heaviest users of cell phones that only barely achieved statistical significance and no increased risk of meningioma. Moreover, as I pointed out a year ago, among the heaviest users were reports of implausible levels of cell phone use, as high as 12 hours per day, every day. When a different method of quantifying cell phone use--asking how many calls per day a person typically made--was used, the increased risk of cancer disappeared.
The New York Times:
The research is plagued by methodological problems. Over all, the Interphone study suggested that cellphone users are less likely to get cancer. Nobody believes that cellphones protect you from cancer, so the finding is considered an anomaly, attributable to biases and errors in the data. Critics say you can’t pick and choose. If one finding must be dismissed because of faulty data, then so must the others.
Moreover, if cellphones caused brain tumors, we should have seen a worldwide increase in brain tumors pandemic as the phones became ubiquitous. That hasn’t happened.
“If you look at brain cancer around the world over 25 years that cellphones have been in use, there’s no suggestion at all of any increase in rates,” said Dr. Meir J. Stampfer, a professor at the Harvard School of Public Health and a consultant to the cellphone industry. “In science, unlike math, we can’t have absolute certainty, but in the scheme of things, this is not a health risk I would be concerned about at all.”
We are faced with a paradox in our increasingly health-conscious society. It is simply a fact of life that research is going to be done on topics like cellphones. But we can never prove a negative or exclude the possibility of a miniscule risk, no matter how large the study. So even when expert bodies concede that there is no convincing evidence of a threat, we get impossibly vague advisories like the current one warning us of "possible carcinogenicity."
In an echo of the Harvard incident, Donald Berry, a professor of biostatistics at M.D. Anderson Cancer Center at the University of Texas, said "anything is a possible carcinogen." Speaking from his cellphone, he added, "This is not something I worry about and it will not in any way change how I use my cellphone."
It's mildy amusing to note that mobile phone use appears to be prevent brain cancer among people who have ever made a cell phone call. Even among top ten percent of heavy users, their risk of brain cancer was well below Shapiro's 2.0 relative risk threshold.
Interestingly, as the number of cell phone subscriptions in the U.S. has risen from 1 million in 1987 to over 300 million today, the National Cancer Institute reports that brain cancer incidence [PDF] has been trending slightly downward.
And on and on. Fortunately, the reality-based version of this story was pretty well covered – and a new study came out last week that swung the pendulum in the other direction. Unfortunately, the reality-based version wasn’t the one that got all the short blurbs in the sources most Americans get their news from – local papers, popular sites like CNN.com, the evening news. Which leaves the average Joe who isn’t following this stuff from 20 different sources and sifting through the conflicting views for hours on end wondering what to believe.
As somebody who is more than a little concerned with what can and cannot cause cancer, this stuff really irks me. Because every time we come up with some new cancer boogeyman – this week it’s cell phones, last week it was sugar, a couple decades ago it was coffee, and in between, I’m sure there are a couple thousand – everybody pays just a little less attention. This isn’t a unique phenomenon. Next time you hear a fire alarm, count the number of people who react as if the building is actually on fire.
But with cancer, this stuff can kill. Contrary to popular belief, we already have some pretty good cures for cancer: prevention and early detection. But when we cook up a new cancer hysteria every couple months, it becomes harder for people to determine what is really truly dangerous, and what is just the latest fad. I’m probably more on top of cancer news than most people, and even I have reached the point where I just say, “screw it, I’m not paying attention,” to this stuff. And judging by the number of people still drinking coffee with sugar while talking on their cell phone, many others have as well.
The bottom line is that we just don’t understand a lot of these things as well as we would like, and we probably never will. Google “coffee and cancer” and you’ll find the article I linked to above that says coffee causes pancreatic cancer…and a bunch of other articles that report that drinking coffee lowers the risk of prostate cancer. There’s evidence that shows that mild cell phone use actually reduces the risk of cancer – an impossibility that is rightfully labeled statistical error, but is nonetheless indicative of the uncertain nature of these studies.
But uncertainty and reality don’t always make for good headlines and press releases. So the WHO and the media decided to take that route, and spit out a bunch of garbage that was misleading at best, downright false at worst. And while the next big cancer scare will make for some nice headlines, it will also desensitize people to the next big cancer scare, and the next one, and the next one, and, possibly, a real one.