No clear signal: is there a link between cellphones and cancer?

The International Agency for Research on Cancer (IARC), an arm of the World Health Organization, last week published a report based on more than a decade of longstanding research into cellphone radiation, reaching the conclusion that it might lead to brain cancer.

But the announcement has puzzled many health officials, who have questioned its timing, saying it raises more questions than it answers.

In response to mounting public concern over recent years about the possible medical harm from the use of cellphones, the IARC set up a working group of 31 scientists from 14 countries to assess the potential hazards. Its conclusions are that exposure to electromagnetic fields emitted by mobile telephones could possibly cause cancer, including an increased risk of a malignant type of brain tumor. According to Dr Christopher Wild, IARC Director, there are approaches people can take, such as sending text messages or using hands-free systems to reduce or limit exposure for the moment.

"I only wish people had taken notice when we said sun beds caused cancer"

"This is a worst-case scenario for the public as well as the media"

"The heaviest exposure is because the cellphone is close to the head, and when you speak in a cellphone, there are pulses of energy which go right into your head," said Dr Robert Baan, senior scientist and officer in charge of the IARC, last week.

Wild said last week: "Given the potential consequences for public health of this classification and findings it is important that additional research be conducted into the long-term, heavy use of mobile phones. Pending the availability of such information, it is important to take pragmatic measures to reduce exposure such as hands-free devices or texting," he added before concluding: "It's up to consumers to decide what they want to do."

The number of cellphone users is now estimated at five billion globally, nearly three-quarters of the world population. Since cellphones are so popular, it may be impossible for experts to compare users who develop brain tumors with people who don't use the devices.

The IARC's announcement has been widely criticized by governments, cancer patient associations, along with medics, who all say that it will alarm many people while failing to provide them with clear guidelines about the possible risks they face.

"All that the IARC has done is to spread alarm," says Emilio Alba, the president of the Spanish Society for Oncological Medicine (SEOM). "It's like throwing a stone into a pond, which simply creates endless ripples. People are now irreversibly dependent on mobile phones - they have changed the way that we work and the way that we socialize. This isn't like tobacco, which may be difficult to quit despite the evidence, but at least we can tell people they should stop smoking," he says.

Alba describes the IARC's approach as "at best, irresponsible," and says that the WHO and the IARC should have worked out a joint communiqué. "All they have done is to raise more questions. What are we supposed to do with this information? Are we supposed to stop our children using cellphones? This announcement shouldn't have just been released; they should have thought about how best to communicate this," he says.

Ildefonso Hernández, a professor of Public Health at the Alicante-based Miguel Hernández University, says that while the IARC's experts were right to call a press conference to outline their conclusions, they should have thought more deeply about the likely repercussions of their words. "They have dodged the issue. This way they don't have to tell people not to use mobile phones and get into conflict with the cellphone industry. At the same time, they aren't saying there are no dangers, when subsequent research might show that there is. But you can't just go around issuing vague warnings."

For its part, the World Health Organization's first response has been to try to distance itself from the findings. María Neira, the WHO's public health and environment director, says that although it is part of the WHO and funded by it, the IARC is "an independent body." She claims that she was not informed of the IARC's findings, which caught her by surprise. Based on previous work by the IARC on cellphones, Neira says she had been expecting a "non-classifiable" risk evaluation, meaning that there is no evidence as yet to show that using a cellphone increases the risk of developing cancer.

Neira adds that the IARC's job is not to give recommendations on public health. "They have done what they had to do," she says, referring to last week's announcement, adding that it is the WHO's remit to advise the public on health protection. She points to the example of caffeine, which is classified - along with 588 other factors and substances - in the same risk group as cellphones. "We tell people to drink coffee in moderation, but sometimes we go for years without issuing any warnings."

Neira goes on to explain that the IARC is "a group of scientists who produce scientific reports that are not aimed at the general public. That's why the report is full of conditional factors. It doesn't say that there is scientific evidence showing that cellphones cause cancer; it says 'there could be' or 'perhaps'. Most of the time, people pay no attention to the IARC: I only wish people had taken notice when it produced its report on sun beds, the cancer links to which are proven," she adds.

The IARC has been researching possible links to brain tumors and cellphone use for a decade: in 2009 it announced that its 30-million-euro, decade-long Interphone investigation overseen by the WHO had compiled evidence showing that heavy users face a higher risk of developing brain tumors later in life, but was unable to define what heavy use constituted and who was most at risk.

Barcelona-based IARC scientist Elisabeth Cardis oversaw the Interphone cellphone study, the findings of which have been used in the latest IARC report. Speaking in 2003, she said: "We have set up a study in which we gave ourselves all of the chances to find an effect, if it exists. The risk of cancer is not very high at the individual level, but if you multiply by a billion users around the world, that could mean hundreds or thousands of cancers around the world... so it's obviously important to determine whether there's a risk and how big that risk is."

The Interphone study looked at more than 5,000 cellphone users with brain tumors in 13 countries to see if they used their cellphones differently to normal users. This type of epidemiological study has been done several times before but has always been criticized - either as not sufficiently long-term in approach or not specific enough to find any conclusive link to cancer.

Neira says that the public has been waiting for a definitive answer to the possible risk from cellphones, and the IARC's results have led to disappointment because they are inconclusive. That said, the IARC's findings put mobile phone use in the same "carcinogenic hazard" category as lead, engine exhaust fumes and chloroform. For this reason, says Neira, the decision was made to call a press conference to announce the IARC'S findings.

"If they had simply passed their results to the WHO without saying anything, we would have been accused of trying to hide things, of trying to protect the cellphone industry. Imagine if the results were handed to us and we sat on them, then people would really be baying for my blood," Neira argues.

She backs the report's conclusion that no further recommendations be made about the possible dangers from mobile phones. "I'm not going to do anything. The only thing we can do is to continue investigating, and to remain vigilant," she says, adding that as soon as the report was made public her own father rang her up - from his cellphone - to ask what he should do: "I told him that he didn't need to do anything."

Pressure will now be on health departments, who will have to extrapolate something from the IARC's report and explain to the public the possible risks. José Martínez Olmos, the Spanish Health Ministry's secretary general, points to a communication failure: "This is what happens when scientists and politicians fail to talk to each other. When news like this is going to be announced, we have to be able to give people real information that they can use."

Olmos argues that the WHO should have prepared a list of recommendations - "even something as simple as saying that the public should continue using phones in the same way as now. They should have said something."

This isn't the first time the WHO has failed to get a clear message across. There is a widely held perception that the WHO overreacted when it announced the dangers of Type A flu in 2008 - "and there was a real danger there" - says Olmos. He says episodes like this will only deepen skepticism about the WHO's findings. "It doesn't matter how scientific a report is - you can't go around saying what you like, especially when you are dealing with something that worries people as much as cancer does, and when something like the mobile phone, which we all use, is involved," he adds.

"We set off an alarm without giving the public any way out," says Elsa González, president of the Federation of Spanish Journalists' Associations. Not that she blames the IARC and the WHO entirely. "This is a shared responsibility. On the one hand you have the source. If it isn't a credible one, then we shouldn't give it too much importance; and if it is a credible source, then we should still question it. Then there is the media, and often, journalists are not as demanding with their sources as they should be. Then there is the temptation to sensationalize, to create headlines to attract readers, and that is playing with fire," she adds. "Finally, there is the government. We have been talking about this subject for some time, about living close to nuclear plants, and I blame the Health Ministry for not commissioning in-depth studies. And the reason they don't has nothing to do with cutbacks. The government has been ignoring this topic for a long time."

"This is a worst-case scenario for the public as well as the media," says Francisco Cañizares, President of the National Association of Health Journalists. "But of course we are used to this kind of thing from the WHO, after the Type A scare," he adds.

What's more, Cañizares argues that the medical community is far from convinced by the IARC's conclusions. "What they have done is a meta-analysis; they have put together something based on reports that have already been published. There is no new research here," he points out.

Emilio Alba is also puzzled: "Unless they have something up their sleeve and they are going to announce it in July, when the report is published in The Lancet, I can't understand where they have drawn their conclusions from, which wouldn't make sense, because the Interphone study reached the conclusion that there is no evidence that the radiation produced by a cellphone can cause cancer, and that they would have to continue research. The Spanish Anti-cancer Association said the IARC's report "lacked the desired scientific rigor."

The Spanish Health Ministry is still waiting for the WHO to react. "It has to make an official statement, and we will demand that it does," says Martínez Olmos. "It has to be more careful when making these kinds of statements. There are rules," he points out.

In the meantime, Martínez Olmos is having to handle a lot of calls, to his cellphone.