WHO Classifies Cell Phones as Possibly Carcinogenic to Humans, ACS Responds
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.
Over the last few years, there has been mounting concern about the possibility of adverse health effects resulting from exposure to radiofrequency electromagnetic fields, such as those emitted by wireless communication devices. The number of mobile phone subscriptions is estimated at 5 billion globally.
From May 24–31 2011, a Working Group of 31 scientists from 14 countries has been meeting at IARC in Lyon, France, to assess the potential carcinogenic hazards from exposure to radiofrequency electromagnetic fields. These assessments will be published as Volume 102 of the IARC Monographs, which will be the fifth volume in this series to focus on physical agents, after Volume 55 (Solar Radiation), Volume 75 and Volume 78 on ionizing radiation (X‐rays, gamma‐rays, neutrons, radio‐nuclides), and Volume 80 on non‐ionizing radiation (extremely low‐frequency electromagnetic fields).
The IARC Monograph Working Group discussed the possibility that these exposures might induce long‐term health effects, in particular an increased risk for cancer. This has relevance for public health, particularly for users of mobile phones, as the number of users is large and growing, particularly among young adults and children.
The IARC Monograph Working Group discussed and evaluated the available literature on the following exposure categories involving radiofrequency electromagnetic fields:
- occupational exposures to radar and to microwaves;
- environmental exposures associated with transmission of signals for radio, television and wireless telecommunication; and
personal exposures associated with the use of wireless telephones.
- International experts shared the complex task of tackling the exposure data, the studies of cancer in humans, the studies of cancer in experimental animals, and the mechanistic and other relevant data.
The evidence was reviewed critically, and overall evaluated as being limited among users of wireless telephones for glioma and acoustic neuroma, and inadequate to draw conclusions for other types of cancers. The evidence from the occupational and environmental exposures mentioned above was similarly judged inadequate. The Working Group did not quantitate the risk; however, one study of past cell phone use (up to the year 2004), showed a 40-percent increased risk for gliomas in the highest category of heavy users (reported average: 30 minutes per day over a 10‐year period).
Dr. Jonathan Samet from the University of Southern California and 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 articles4 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.
"This report comes from a very credible group, and reaches reasonable conclusions about electromagnetic radiation from cellphones and other devices. It is critical that its findings be interpreted with great care. The working group reviewed a large number of studies and concluded that there was limited evidence that cell phones may cause glioma, a type of brain tumor that starts in the brain or spine. A 2B classification means that there could be some risk, but that the evidence is not strong enough to be considered causal, and needs to be investigated further. The bottom line is the evidence is enough to warrant concern, but it is not conclusive.
"The American Cancer Society does not independently judge the carcinogenicity of different exposures. Instead, we rely on IARC reviews of available evidence for our recommendations. At first glance, these new recommendations are very much in line with the American Cancer Society's current information that the evidence is limited, that further research is needed, and that there are things people who are concerned about radiofrequency exposure can do to limit their exposure, including using an ear piece and limiting cell phone use, particularly among children.
"Given that the evidence remains uncertain, it is up to each individual to determine what changes they wish to make, if any, after weighing the potential benefits and risks of using a cell phone. If some feel the potential risk outweighs the benefit, they can take actions, including limiting cell phone use, or using a headset. Limiting use among children also seems reasonable in light of this uncertainty. On the other hand, if someone is of the opinion that the absence of strong scientific evidence on the harms of cell phone use is reassuring, they may take different actions, and it would be hard to criticize that.
"It's also important to put this 2B classification into perspective. Many common exposures are classified in Category 2B, including gasoline exhaust and even coffee."