London, Feb 7 : The rapid increase in mobile phone use has raised public concern about whether or not they can lead to brain cancer. Now, a study by scientists in Japan has lain to rest these fears by finding that mobile use does not increase the risk of brain tumours.
The finding is significant as it is the first to consider the effects of radiation on different parts of the brain.
The tumours that were analysed for in this study were meningioma - the most common benign tumour, glioma - a type of primary central nervous system (CNS) tumour, and pituitary adenoma - tumours that occur in the pituitary gland.
The study is the first epidemiological study to take into account the different exposure levels inside the intracranial space. Exposure is localised close to the relevant ear, whereas glioma and meningioma develop at a variety of sites.
As a part of the study, scientists at Tokyo Women's Medical University led by Dr N Yamaguchi compared phone use in 322 brain cancer patients with 683 healthy people.
The case group consisted of newly diagnosed 132 meningioma patients, 88 glioma patients, and 102 pituitary adenoma patients between the ages of 30-69 years treated in participating hospitals, with case recruitment performed prospectively from December 2000 to November 2004.
Controls were selected from the general population by random digit dialling, in which phone numbers for home fixed-phones were generated randomly.
Volunteers were individually matched for age (within a 5-year range), sex, and residence with the cases.
A brief questionnaire was administered over the phone or via a self-administered paper questionnaire to those who did not agree to face-to-face interviews, to compare phone use between participants and non-participants among eligible controls.
During the study, subjects were asked about their mobile phone use, including the dates of starting and stopping to use each phone, the average duration and frequency of calls, and other usage patterns in chronological order.
Use of the Personal Handy-phone System (PHS), a type of cordless telephone system, was also recorded. Demographic variables, medical history, and occupational history were also recorded. Clinical information on the cases was obtained from the relevant department.
Regular mobile phone use was defined as used at least once a week for 6 months.
Based on their research, the boffins stated that they had found no association between mobile phone use and cancer, providing more evidence to suggest they don't cause brain cancer.
The findings of the study are published in the British Journal of Cancer.