Cell phones and cancer – link established

By Dr. Ananya Mandal, MDJun 1 2011

In its latest announcement the World Health Organization (WHO) said that radiation from cell phones can possibly cause cancer. According to the WHO's International Agency for Research on Cancer (IARC), radiofrequency electromagnetic fields have been classified as possibly carcinogenic to humans (group 2B) on the basis of an increased risk for glioma that some studies have associated with the use of wireless phones.

This conclusion was drawn from an extensive review of studies on cell phone safety by a working group of 31 scientists from 14 countries, who have been meeting regularly to evaluate the potential carcinogenic hazards from exposure to radiofrequency electromagnetic fields. They reviewed exposure data, studies of cancer in humans and experimental animal models, and other relevant data.

The IARC Monograph Working Group discussed and evaluated literature that included several exposure categories involving radiofrequency electromagnetic fields like occupational exposure to radar and to microwaves, environmental exposures associated with transmission of signals for radio, television, and wireless telecommunication and personal exposures associated with the use of wireless telephones.

According to IARC Director Christopher Wild, “Given the potential consequences for public health of this classification and findings it is important that additional research be conducted into the long-term, heavy use of mobile phones. Pending the availability of such information, it is important to take pragmatic measures to reduce exposure such as hands-free devices or texting.” An estimated 5 billion people globally use cell phones. In particular, some data have suggested that their use, especially over the long term, represent a “significant” risk for brain tumors. But study results have been inconsistent, although some European countries have taken precautionary measures aimed specifically at children.

Some of the strongest evidence supporting a link between brain tumors and cell phone use comes from a series of Swedish studies, led by Lennart Hardell, from the Department of Oncology, Orebro Medical Center. These studies showed that risk increased with the number of cumulative hours of use, higher radiated power, and length of cell phone use. They also reported that younger users had a higher risk.

One study of past cell phone use cited in the report showed a “40% increased risk for gliomas in the highest category of heavy users (reported average: 30 minutes per day over a 10‐year period).” This is a reversal from their prior position that cancer was unlikely to be caused by cellular phones or their base stations and that reviews had found no convincing evidence for other health effects. The evidence for glioma (a malignant type of brain cancer) was evaluated as “limited,” defined as “A positive association has been observed between exposure to the agent and cancer for which a causal interpretation is considered by the Working Group to be credible, but chance, bias or confounding could not be ruled out with reasonable confidence.” Evidence for other types of cancer was considered “inadequate,” defined as “The available studies are of insufficient quality, consistency or statistical power to permit a conclusion regarding the presence or absence of a causal association between exposure and cancer, or no data on cancer in humans are available.” The report ultimately concluded that “the evidence...is strong enough to support a conclusion" and that "it is important to take pragmatic measures to reduce exposure.”

Studies have been inconclusive with some saying cell phones are harmless. Consistent with the literature, there is no consensus among physicians and scientists about the severity of risk, or if one even exists. The National Cancer Institute, for example, has stated that although a consistent link has not been established between cell phone use and cancer, “scientists feel that additional research is needed before firm conclusions can be drawn.” In a similar fashion, the American Cancer Society points out that even though the weight of the evidence has shown no association between cell phone use and brain cancer, information on the potential health effects of very long-term use, or use in children, is simply not available.

This protect titled International Electromagnetic Fields (EMF) Project was launched by the WHO in 1996, in response to public and governmental concern, with the goal of evaluating the possibility of adverse health effects from electromagnetic fields. Jonathan Samet, MD, chairman of the working group, notes that “the evidence, while still accumulating, is strong enough to support a conclusion and the 2B classification.” “The conclusion means that there could be some risk, and therefore we need to keep a close watch for a link between cell phones and cancer risk,” he said.

A full report summarizing the main conclusions and evaluations of the IARC Working Group is slated to be published online soon in The Lancet Oncology and in print in its July 1 issue.

A global wireless industry group Thursday disputed the significance of a report released by a UN health organization citing a potential cancer link from use of mobile phones.

CTIA-The Wireless Association said the UN agency "conducts numerous reviews and in the past has given the same score to, for example, pickled vegetables and coffee."

This classification "does not mean cell phones cause cancer," the industry association said in a statement, noting that "limited evidence from statistical studies can be found even though bias and other data flaws may be the basis for the results."
The reaction came after the World Health Organization's cancer research agency said the use of cell phones and other wireless communication devices are "possibly carcinogenic to humans."

The radio frequency electromagnetic fields generated by such devices were deemed as potential cancer agents "based on an increased risk for glioma, a malignant type of brain cancer," the International Agency for Research on Cancer (IARC) said in a statement.
A group of experts meeting in the French city of Lyon over the past eight days "reached this classification based on its review of the human evidence coming from epidemiological studies," said Jonathan Samet, president of the work group.

The wireless association said the IARC working group "did not conduct any new research, but rather reviewed published studies."

It also noted that the US Federal Communications Commission "has concluded that 'there's no scientific evidence that proves that wireless phone usage can lead to cancer'" and that the US Food and Drug Administration has also stated that "'the weight of scientific evidence has not linked cell phones with any health problems.'"