The largest study to date, published last year, looked at almost 13,000 mobile phone users over 10 years.
Swerdlow and colleagues analyzed its results in detail but concluded it gave no clear answer and had several methodological problems, since it was based on interviews and asked subjects to recall phone use going back several years.
Significantly, other studies from several countries have shown no indication of increases in brain tumors up to 20 years after the introduction of mobile phones and 10 years after their use became widespread, they added.
Proving an absence of association is always far harder in science than finding one, and Swerdlow said it should become much clearer over the next few years whether or not there was any plausible link.
“This is a really difficult issue to research,” said David Spiegelhalter, Winton Professor of the Public Understanding of Risk at the University of Cambridge, who was not involved in the study.
“But even given the limitations of the evidence, this report is clear that any risk appears to be so small that it is very hard to detect — even in the masses of people now using mobile phones.”
Swerdlow is chairman of the International Commission on Non-Ionizing Radiation Protection’s Standing Committee on Epidemiology. The commission is the international body, recognized by the WHO, that constructs guidelines for exposure limits for non-ionizing radiation.
Since mobile phones have become such a key part of daily life — used by many for websurfing as well as talking — industry experts say a health threat is unlikely to stop people using them.
Cambodia, Phnom Penh,
City of Lithgow Australia
Ontario California USA
Tucson Arizona USA
Egypt Cairo: city limits
Click on any of the pictures below
to learn more