A San Francisco Regulation Raises the Question: Do Cell Phones Cause Cancer?
Do you know how much radiation your cell phone emits? You will from now on if you live in San Francisco. Yesterday the city's Board of Supervisors voted to require all retailers to display the amount of radiation a phone emits, a regulation that's believed to be the first in the U.S. The new ruling, which Mayor Gavin Newsom is expected to sign into law soon, doesn't require retailers to say anything about the potential dangers of cell phone radiation, but just ensures that the information—which is usually buried in the back of a handset's manual—is clearly presented to shoppers, as mayoral spokesperson Tony Winnicker told the Times:
It's information that's out there if you're willing to look hard enough. And we think that for the consumer for whom this is an area of concern, it ought to be easier to find.
The wireless industry, unsurprisingly, opposed the bill, arguing that the requirement would only confuse shoppers, as John Walls, a spokesperson for the Wireless Association, an industry trade group, told the San Francisco Chronicle:
Rather than inform, the ordinance will potentially mislead consumers with point-of-sale requirements suggesting that some phones are 'safer' than others, based on radio frequency emissions.
Walls went on to point out that all phones sold in the U.S. are required to have radiation levels below the Federal Communications Commission standard of 1.6 watts per kilogram of body tissue—and that there's an overwhelming scientific consensus that there are no adverse health effects from using cell phones. But that's not absolutely certain—and there handset models have a wide range of radiation levels, as this website from the Environmental Working Group shows. While the World Health Organization and the National Cancer Institute have said that there isn't enough evidence to support the idea that cell phones are a health threat, the science around mobiles and brain cancer remains muddled. There's no clearly proven risk, but there is enough evidence to be concerned, especially about young users or those on their phone all day long. Here's what I wrote about the issue in the Mar. 15 edition of TIME:
The wireless industry contends that RF radiation lacks the strength to alter molecules in the human body; the Federal Communications Commission (FCC) maximum for cell-phone-signal exposure is intended to prevent RF radiation from heating tissue to the point that cells are damaged. Cell-phone RF radiation's "effect on the body, at least at this time, appears to be insufficient to produce genetic damage typically associated with developing cancer," Dr. Robert Hoover, director of the National Cancer Institute's Epidemiology and Biostatistics Program, testified at a 2008 congressional hearing.
But the body of research is far from conclusive. In 1995, [University of Washington neurologist Henry] Lai co-wrote a study showing that a single two-hour exposure of RF radiation — at levels considered safe by U.S. standards — produced the sort of genetic damage in rats' brain cells that can lead to cancer. Though subsequent researchers — often funded in part by the wireless industry — failed to replicate Lai's results, a 2004 European Union — funded study reported similar findings.
Dariusz Leszczynski, a research professor at Finland's Radiation and Nuclear Safety Authority in Helsinki, has done studies indicating that RF radiation may create a stress reaction in the cells that line blood vessels, leading to a dangerous breach in the blood-brain barrier. "Mobile-phone radiation may be able to indirectly hurt cells, perhaps by interfering with their ability to repair normal DNA damage," he says. "Given the scientific uncertainty, it's premature to say the use of cell phones is safe."
The best way to answer the question would be through long-term epidemiological studies—which is why the International Agency for Research on Cancer launched the Interphone study years ago. That $24 million study matched rates of brain cancer with cell-phone use among more than 12,000 participants in 13 countries; the results were finally made public last month, after years of delay. Instead of providing a definitive assessment of the risks of cell phones, though, Interphone kept muddying the waters:
The study, which will be published this week in the International Journal of Epidemiology, found that, overall, there is no clear connection between cell-phone use and brain cancer. "An increased risk of brain cancer is not established from the data from Interphone," says Dr. Christopher Wild, director of the International Agency for Research on Cancer, which helped coordinate the study.But upon closer inspection, the results were checkered: the 10% of people who used their phones most often and for the longest period of time — 30 minutes a day or more on average for at least 10 years — had a substantially higher risk of developing some form of brain cancer than those who didn't use a mobile phone at all. Meanwhile, people who used their cell phones infrequently had a lower risk of developing some brain tumors than those who exclusively used corded telephones — as if mobile phones in small doses might offer some protection from brain cancer.
Interphone had a number of methodological problems—the fact that all but the heaviest users of cell phones in the study actually had a smaller chance of getting brain cancer than those who had never used a phone at all indicates that, in the technical argot, something ain't quite right here. It didn't help that the study defined "heavy" users—who had a 40% higher incidence of the brain tumor glioma than the control group—as those who used their phones at least 30 minute a day. Average use in the U.S. now is 21 minutes a day—and we all know people who use their phones far more often. An editorial by the epidemiologists Rodolfo Saracci and Jonathan Samet that accompanied the study concluded: "Bias stands as the most likely explanation of the observed results."
In addition, a study released on Monday by Lloyd Morgan, a senior research fellow at the Environmental Health Trust—and a long-time critic of the wireless industry—and a group of other cancer researchers, argued that Interphone may have underestimated the risk of brain cancer with cell phone use by as much as 25%, and that the results could be dire, as Morgan puts it:
What we have discovered indicates there is going to be one hell of a brain tumor pandemic unless people are warned and encouraged to change current cell phone use behaviors. Governments should not soft-peddle this critical public health issue but instead rapidly educate citizens on the risks. People should hear the message clearly that cell phones should be kept away from one's head and body at all times.
Still, scientists haven't yet found a clear pathway by which cell phone radiation could clearly cause cancer—and it will always be difficult to design an epidemiological study that could properly gauge the risk of cell-phone use, especially as mobiles become more and more ubiquitous. (Right now most studies rely on users to try to remember how often they used their phones—think you could do that?.) The good news is that there are simple ways to cut your exposure to cell-phone radiation anyway, simply by using a wired headset; unlike cigarettes and lung cancer, there's no need to ditch mobiles altogether. That's a good—and not just because I'm surgically attached to my iPhone. Billions of people use cell phones around the world today—4 billion actually—a far greater percentage of the population than have ever smoked. Even if cell-phone use raises the risk of brain tumors a little bit, that could have a major impact on public health—and because brain cancers can take decades to develop, we might not know until it's too late. This is a case where it's better to be safe than sorry—as San Francisco showed.
