Cellphones have been classed in category 2B – possibly carcinogenic to humans – by the cancer arm of the World Health Organization (WHO), after an international panel of experts evaluated hundreds of scientific articles. The IARC (International Agency for Research on Cancer) was focusing on electromagnetic radiation, which emanates from radar, microwaves and cellphones (mobile phones).

Category 2B includes gasoline engine exhaust, glass wool, styrene, lead and DDT.

In a communiqué, WHO wrote: “The WHO/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 cancer1, associated with wireless phone use.”

The authors explained as background information that concern has been growing regarding the possible health hazards posed by radiofrequency electromagnetic fields, such as those emitted by mobile phones. There are estimated to be 5 billion cellphone subscriptions worldwide.

The IARC Monograph Working Group, consisting of 31 scientists from 14 countries met at IARC in Lyon, France. They were asked to examine what the long-term health effects might be after exposure to radiofrequency electromagnetic fields, including the risk of cancer. As the number of mobile phone users has grown rapidly, especially among younger users, their findings may have relevance for public health.

The Working Group evaluated and discussed a large number of studies on the following types of radiofrequency electromagnetic field exposures:

  • Exposure to radar and microwaves in the workplace
  • Environmental exposure to the transmissions of radio, TV and wireless telecommunication signals
  • Personal exposure related to wireless telephone usage

The authors say they reviewed the data carefully and critically, and believe wireless telephone usage is limited to a risk of glioma and acoustic neuroma (a benign but life-threatening tumor). They added that there was not enough data to make any conclusions regarding the risk of developing other types of cancers.

They added that there was not enough compelling evidence to draw any conclusions regarding health risks linked to occupational and environmental exposures.

They quoted a study which looked at cellphone usage up to the year 2004 which showed a 40% higher risk of gliomas among very heavy users – people who had been on the cellphones for at least 30 minutes per day for ten years.

Working Group Chairman, Dr Jonathan Samet, said:

“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.”

Christopher Wild, ARC Director, said:

“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. “

The Working Group said that a concise report containing its main conclusions will be published in medical journal The Lancet Oncology on July 1st, 2011.

Written by Christian Nordqvist