BALTIMORE, United States-The World Health Organization (WHO) is assessing the feasibility of conducting a multi-nation study to determine the connection, if any, between mobile-phone use and cancers in the brain, head and neck.
Countries collaborating on the research initiative include Australia, Britain, Canada, France, Israel, Italy and Sweden.
A case-control study would target populations in those countries who have had sufficient long-term use of mobile phones-identifying persons with the cancers of interest and comparing their past mobile-phone use with the mobile-phone use of others of comparable age, sex and other factors.
The decision on whether to move forward with the case-control study, however, hinges on the results of a pilot study designed to determine, among other things, if enough relevant information can be collected on radio-frequency (RF) exposure to mobile phones.
“The main problem is that we need historical information-how much the study subjects used their phones two years ago, five years ago or more,” said Dr. Elisabeth Cardis, who heads the Program on Radiation and Cancer at the International Agency for Research on Cancer (IARC), the WHO organization specializing in cancer research. “We need to determine how reliable the (study subject’s) own recall is. We also need to determine the feasibility of validating (or) complementing their answers with billing records. This means finding out whether archived historical records are sufficiently detailed for this purpose.”
Results of the pilot study are expected this fall. If the results reveal that the necessary information cannot be obtained, the case-control study will be cancelled. If, on the other hand, it is determined that sufficiently reliable data can be collected, then funding will be sought from the European Union and the work will proceed.
Cardis said a case-control study would last three to four years and would contain information about analog and digital phones, as well as other sources of RF exposure.
The multi-nation initiative is part of WHO’s International Electromagnetic Fields (EMF) Project, a program launched in May 1996 in response to growing public health concerns in WHO’s member states about possible adverse health effects from exposure to an ever-increasing number and diversity of EMF sources. Scheduled to last for five years, the EMF Project pools current knowledge and available resources of key international and national agencies and scientific institutions in an effort to reach scientifically sound recommendations for health-risk assessments of exposure to electrical and RF magnetic fields up to 300 GHz.
A scientific review by WHO held under the EMF Project in Munich in November 1996 concluded that “from the current scientific literature, there is no convincing evidence that exposure to RF shortens the life span of humans, induces or promotes cancer.”
But the same review also stressed that “further studies are needed to draw a more complete picture of health risks, especially about possible cancer risk from exposure to low levels of RF exposure.”
Again, at a meeting in Geneva in December, EMF Project research managers and scientists reaffirmed that “analysis of current epidemiological studies of people exposed to low levels of RF has not shown any adverse health effects.” They added, however, that “mobile-telephone use is relatively new” and recommended additional studies “preferably on mobile-telephone users.” The multi-nation research initiative is a response to that recommendation.
Meanwhile, in the United States scientists are engaged in research similar to that performed by University of Washington scientist Dr. Henry Lai, who several years ago found single- and double-strand DNA breaks in rats exposed to low-level microwave radiation after a couple of hours. The follow-up work is being done by Wireless Technology Research L.L.C. (WTR), the organization performing RF research for the U.S. cellular industry.
Rather than expose a rat’s entire body to radiation, as in most studies, WTR scientists are using a head-only exposure method, which they claim more closely parallels human cell-phone use.
“If we could do tests on humans, we wouldn’t expose the entire body, just the head,” said Sue O’Donnell, director of public affairs for the WTR project. “So we spent a great deal of time developing a head-only system that measures the dosage in the heads of the rats as well as what’s called the dose response. We think it’s pretty state-of-the-art.” O’Donnell said the tests should be completed by early summer.
“There are a lot of independent bodies around the world looking at all of this research very closely,” said Norman Sandler, director of global strategic issues for Motorola Inc., which is one of the world’s largest wireless handset manufacturers. “And today all of them come to the same basic conclusion, which is there is no scientific basis for any kind of concern about a public health risk. “But to the extent that the public is concerned or has questions and wants additional proof of safety, we will endeavor … to provide that assurance.”
