After years of research and a great deal of argument, the World Health Organization has classified cellphones as possibly carcinogenic.
It's given them a Group 2B health warning, based on an increased risk for the malignant brain cancer glioma.
"The evidence, while still accumulating, is strong enough to support a conclusion and the 2B classification," says Dr Jonathan Samet of theUniversity of Southern California and chairman of the working group.
"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."
This time last year, the WHO's International Agency for Research on Cancer (IARC) concluded that heavy phone use did appear to cause cancer, and other studies since have supported this view.
And, over the last week, a working group of 31 scientists from 14 countries has been evaluating the risks of electromagnetic radiation, looking at occupational exposure to radar and to microwaves, environmental exposures associated with transmission of TV, radio and wireless signals and personal exposure from the use of cellphones.
The group considered hundreds of scientific articles relating to cellphone use.
Once again, the team decided that there wasn't enough evidence to say definitively that cellphones cause cancer. However it cited one major study of cellphone use up to 2004, which showed a 40 percent increased risk for gliomas in people who used a phone fof 30 minutes per day over a 10‐year period - and decided that a warning was necessary.
"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," says IARC Director Christopher Wild.
"Pending the availability of such information, it is important to take pragmatic measures to reduce exposure such as hands‐free devices or texting. "