On May 31, 2011 the World Health Organization (WHO) announced their classification of radiofrequency (RF) electromagnetic fields emitted from cell phones, used globally by more than 4.6 billion people, as "possibly carcinogenic to humans.” Given the serious health risk that this implies, WHO has pledged to conduct a formal risk assessment of all studied health outcomes from radiofrequency fields exposure by 2012.
The Current Evidence of Cancer Risk
- A study conducted in Denmark from 1982 to 1995 (with a follow-up in 2002) analyzed cancer rates among 420,095 cell phone users and found no increased risk for brain tumors, salivary gland tumors, eye tumors, or leukemia.
- A number of earlier and smaller case–control studies as well as more than 40 experimental studies also found no direct association between cell phone use and cancer.
- The INTERPHONE study, the largest of its kind to date, examined 2,708 glioma and 2,409
meningioma cases in 13 countries using a common protocol. This study found that using a cell phone appeared to slightly lower the risk of developing a glioma, compared with never using one. But, when the highest 10% of cell phone users in terms of call time were analyzed, this subgroup had a 40% increased risk for glioma, compared with those who had never used a cell phone. Thus, according to Interphone, there is a higher risk for tumors occurring on the same side of the brain as cell phone exposure, and especially for tumors located in the temporal lobe, where RF exposure is highest.
- A meeting of 31 scientists organized by the International Agency for Research on Cancer (IARC) in Lyon, France, whose results have been just published in the latest issue of the medical journal The Lancet, considered the potential carcinogenic hazards from exposure to RF electromagnetic fields emitted by cell phones. The IARC group concluded that fields emitted by cell phones should be considered as "possibly carcinogenic" to humans.
- A pooled analysis of Swedish studies examined the association between cell and cordless phone use and glioma, acoustic neuroma, and meningioma in 1,251 (85%) cases and 2,438 (84%) controls. For people who had used a cell phone for more than 1 year, the risk for brain tumors was 1.3 times higher (30%) than in people who had never used a cell phone. This risk increased with time since first use and with total call time. After more than 2000 hours of use, the risk was 3.2 times as high. Similar results were observed among cordless phone users.
In addition to the comprehensive review planned by WHO, the Cohort Study on Mobile Communications (COSMOS) is attempting to do a similarly all-inclusive study. It will become the largest study ever conducted and examine the effects of cell phone use on long-term health. COSMOS plans to track at least 250,000 people in 5 European countries for up to 30 years and it will not rely on users’ self-report, but will follow cell phone use in real time.
The Opinions On Cell Phone Use and Cancer Risk
Dr. Jonathan Samet, Chair of the IARC working group and the Flora L. Thornton Chair of the Department of Preventive Medicine at the Keck School of Medicine, University of Southern California, Los Angeles, , explains that "possibly carcinogenic" means is that cell phone use is not completely safe, although it needs to be more clearly defined through better investigation. If users want to do something about the risk, says Dr. Samet, “there are easy steps to take to lower exposure, such as using hands-free devices and reducing use of the phone."
Other researchers point out that exposure to RF fields is not limited to cell phones but can be caused by other personal devices. Moreover, the specific absorption rate varies from one phone model to another and it can be affected by many factors, including the design, the position of the phone and its antenna in relation to the head, how the phone is held, the anatomy of the head, and the quality of the link between the base station and the phone.
Children are more at risk than adults, since the average RF energy deposition in a child’s brain is generally at least twice as high as in adults. In the most sensitive area of the head, the bone marrow of the skull, exposure in children can be up to 10 times as high as in adults.
Researchers also point out that the INTERPHONE study and the Swedish pooled analysis may not be entirely accurate due to the possibility of "recall error and selection for participation," although the results of these studies cannot be dismissed as reflecting bias alone, since a cause-effect relationship between cell phone-caused exposure to RF fields and brain cancer remains a distinct possibility.
More, Better Research Needed
Where does this leave cell phone users, all 4.6 billion of them? More studies are certainly needed and, perhaps most importantly, the studies need to be better designed. Studies which rely on interviews and on the participants ability to recall the details of their phone use do not produce the most reliable results. Prospective studies that track phone use and health records in real time, that are large enough to include significant segments of the population will produce far more accurate results. They are being planned and, in the case of the COSMOS study, they are underway. Until then, Bluetooth earpieces would seem the way to go.