Mobile phones and cancer: assessing risk in a world of uncertainty

Over the past week, 31 scientists from 14 countries have been meeting at the French headquarters of the International Agency for Research on Cancer (IARC) to assess whether exposure to radiofrequency electromagnetic fields can cause cancer. Yeterday they issued this statement, generating widespread media coverage that mobile phone use may cause cancer. The statement’s release […]

Yeterday they issued this statement, generating widespread media coverage that mobile phone use may cause cancer.

The statement’s release raised some eyebrows as it was ahead of the formal publication of the science behind the announcement.

Here are some relevant extracts from the statement:

The WHO/International Agency for Research on Cancer (IARC) has classified radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group 2B), based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use.

(What Group 2B means: The agent is possibly carcinogenic to humans. This category is used for agents for which there is limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals. It may also be used when there is inadequate evidence of carcinogenicity in humans but there is sufficient evidence of carcinogenicity in experimental animals. In some instances, an agent for which there is inadequate evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals together with supporting evidence from mechanistic and other relevant data may be placed in this group. An agent may be classified in this category solely on the basis of strong evidence from mechanistic and other relevant data.)

Dr Jonathan Samet (University of Southern California, USA), overall Chairman of the Working Group, indicated that “the evidence, while still accumulating, is strong enough to support a conclusion and the 2B classification. The conclusion means that there could be some risk, and therefore we need to keep a close watch for a link between cell phones and cancer risk.”

“Given the potential consequences for public health of this classification and findings,” said IARC Director Christopher Wild, “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.”

The Working Group considered hundreds of scientific articles; the complete list will be published in the Monograph. It is noteworthy to mention that several recent in‐press scientific articles resulting from the Interphone study were made available to the working group shortly before it was due to convene, reflecting their acceptance for publication at that time, and were included in the evaluation.

A concise report summarizing the main conclusions of the IARC Working Group and the evaluations of the carcinogenic hazard from radiofrequency electromagnetic fields (including the use of mobile telephones) will be published in The Lancet Oncology in its July 1 issue, and in a few days online.

The IARC, according to a document that can be downloaded here, has classified 266 agents as group 2B.

These include bracken fern, coffee (for its association with urinary and bladder cancer although it may be associated with reduced risk of bowel cancer), marine diesel fuel, occupational exposure to dry cleaning, lead, perineal use of talc-based body powder, welding fumes, and quite a number of medications.

Some of the related commentary that is worth reading:

A blog by Dr J. Leonard Lichtenfeld, Deputy Chief Medical Officer for the national office of the American Cancer Society, which says that he went back to a blog he previously wrote in 2008 to see whether today’s news would change his advice. It didn’t – what he wrote them remains relevant, he says:

“That leaves us in a situation where each person has to make their own decision, and weigh the benefits and risks of using a cell phone or a cordless phone. If you feel the potential risk outweighs the benefit, you take certain actions. On the other hand, if you are of the opinion that the absence of strong scientific evidence on the harms of cell phone use is reassuring, you take different actions.

“Finally, there are things you can do to reduce your risk, such as using newer digital models which emit less radiation. You can limit your child’s use of cell phones or encourage text messaging (which is basically the only way some children currently use their cell phones anyway.) Finally, you can use a headset, which is what I do and have been doing for many years simply because I find it difficult to constantly hold a cell phone to my head.”

• This blog from Cancer Research UK, which says:

It is understandable that people are concerned about mobile phones, especially because they are so widely used. But so far, the published studies do not show that mobile phones could increase the risk of cancer. This conclusion is backed up by the lack of a solid biological mechanism, and the fact that brain cancer rates are not going up significantly.

However, all of the studies so far have weaknesses, which make it impossible to entirely rule out a risk. Mobile phones are still a new technology and there is little evidence about effects of long-term use.

For this reason, the UK Government advises a precautionary stance. It suggests that if adults want to use a mobile phone, they can choose to minimise their exposure by keeping calls short. It also advises discouraging children under the age of 16 from making non-essential calls as well as also keeping their calls short.

Meanwhile Cancer Council Australia has advised us not be alarmed about the findings, and cites Australian Institute of Health and Welfare data showing that brain cancer incidence has remained steady over a 25 year period to 2007, between 6.3 and 7.3 cases per 100,000 Australians.