The INTERPHONE study was carried out from 2000 to 2004 in 13 countries (Australia, Canada, Denmark, Finland, France, Germany, Israel, Italy, Japan, New Zealand, Norway, Sweden, and UK) as the largest epidemiological study of cell phone use investigating a potential association with the occurrence of brain cancer. The study included 2,765 patients with glioma, a tumor arising from glial cells in the central nervous system; 2,425 patients with meningioma, a tumor arising from the meninges, the membrane surrounding tissues in the central nervous system; 1,121 patients with acoustic neurinoma, a benign tumor of the acoustic nerve; 109 patients with malignant parotid gland tumors; and 7,658 controls. In May 2010, the Interphone Study Group published the results of their evaluation of gliomas and meningiomas in the International Journal of Epidemiology (which unfortunately requires a subscription). The article can be found here. The study population and methodology were described in the European Journal of Epidemiology in 2007 and can be read here.
Overall, the study has found no conclusive increase in brain tumors associated with cell phone use over 10 years. However, the study has some issues. They only looked at adults (people over 30 years of age), not at the younger people who commonly use cell phones for long periods of time. Also, the study is several years old already. The maximum cell phone use by the 10% of participants using the phone more often was 30 minutes a day, much less than the time spent by current users, particularly young users. Also, newer phones have fewer radio wave emissions targeted at the head, and the numerous hands-free devices and prevalence of texting limit the time a phone is against one side of the head, one factor that was found to influence the malignant effects of cell phone use in the INTERPHONE study.
The associated study centers are continuing their research, focusing on younger cell phone users and specific cancers that had some suggestive results (for a full description of the study groups and future analyses click here). The WHO felt that the study may have suggested an increased risk of glioma, but not conclusively. This uncertainty has pervaded the field since cell phone radiation became a studied question. A lack of volunteer human studies leads the World Health Organization (WHO) and other concerned agencies to admit that there is no known risk of cancer when using cell phones (see Leszczynski and Xu, Mobile phone radiation health risk controversy: the reliability and sufficiency of science behind the safety standards. Health Research Policy and Systems, 2010 doi: 10.1186/1478-4505-8-2 by clicking here). That doesn’t appear to have changed with the Interphone results.
However, the study was funded in part by the cell phone manufacturer trade group, Mobile Manufacturers Forum, which supposedly held up the results as the researchers found a way to frame the conclusions from the study (see LATimes). And many media outlets, including the Telegraph, would have readers believe that the researchers found an increased risk of brain cancer if using a cell phone for 30 minutes a day. The WHO press release from May 17, 2010 appears to disagree. The press release about the publication from the International Agency for Research on Cancer, a part of the World Health Organization (WHO) is available here.
TIME has a more substantial criticism of the muddled findings of the INTERPHONE study published in May 2010 and the media response.