Mainz University participates in international study of the relationship between mobile phone use and brain tumor risk
17.05.2010
Interphone is the largest case-control study to date to investigate the link between mobile phones and the risk of cancer. It concludes that average use of mobiles does not present a specific risk, although results are less clear-cut with regard to very frequent users.
Mobile and cordless phones produce high frequency electromagnetic fields during use. According to current knowledge, these represent no risk to health if they remain within the specified maximum limits imposed for safety reasons. Despite this, and not least because of the rapid proliferation of the use of mobile phones, fears of potential risks have continued to surface. As a result, researchers in eight European countries (Denmark, Germany, UK, Finland, France, Italy, Norway and Sweden) and Australia, Israel, Japan, Canada and New Zealand initiated a collaborative study in 2000 that was coordinated by the International Agency for Research on Cancer (IARC) in Lyon. The purpose of the Interphone Study was to use an epidemiological approach to uncover any potential health risks. Because mobiles and cordless phones are brought into direct contact with the head, the primary aim of the study was to find out whether use of mobiles promotes the development of brain cancer (gliomas/meningiomas) in adults.
In the period 2000-2003, a total of 2,765 glioma patients, 2,425 meningioma patients and 7,658 healthy control subjects were asked about their telephoning habits. Interphone is thus the largest case-control study to date to investigate mobile phone usage and cancer risk. Most of those surveyed had only been using mobiles for a short period, although some of the subjects had already started using mobile phones prior to 1994. The overall conclusion was that use of mobile phones is not associated with an increased risk of development of glioma or meningioma. However, when the intensity of use was considered (i.e. the total duration of use in hours), it was found that the risk of glioma was increased in very heavy phone users (5% of participants), particularly in subjects who, according to their own statements, had tended to hold their phones to the side of the head on which a glioma was subsequently diagnosed.
"We are not really in a position to say whether the risk of development of brain cancer is actually higher in these persons as the results may have been influenced by methodological problems," explains Professor Maria Blettner, member of the Interphone Study Group and Director of the Institute of Medical Biostatistics, Epidemiology and Informatics (IMBEI) of the University Medical Center of the Johannes Gutenberg University Mainz. For example, the claims of very high rates of usage made by some of the subjects are simply not plausible. The risk of becoming ill did not, as might be expected, rise with increased usage. Instead, the risk only seemed to be higher in the small group of subjects who made a very high number of calls. Also, exposure to radiation (SAR value) when using mobile phones is much lower now than 10-20 years ago.
According to Professor Maria Blettner "the Interphone Study shows that adults who make average use of their mobile phones are not at increased risk of developing cerebral tumors." Further research will be required to determine whether those who make very frequent and lengthy mobile phones calls actually do run the risk of developing gliomas.
Participation in the study by German researchers
German researchers from the Institute of Medical Biostatistics, Epidemiology and Informatics of Mainz University (study management), the Environmental Epidemiology Workgroup of the German Cancer Research Center in Heidelberg and the Epidemiology and Health Workgroup of Bielefeld University took part in the Interphone Study. The German results were published in 2006 in the periodical American Journal of Epidemiology.