Cellphone Safety: Another Perspective

The Announcement

On May 31, the International Agency for Research on Cancer  (an agency within the World Health Organization) announced results as a year-long analysis reviewing studies assessing the risks of cell phone use.  I'm a bit skeptical and critical of the World Health Organization press-briefing regarding cancer risks associated with cell phone use for a couple of reasons.

First of all (and possibly, most importantly) WHO has not released the manuscript yet, so there is really no way to assess the methodology of their meta-analysis. 

Secondly, the announcement was released as a press-briefing rather than a journal article, so it is not subject to the scrutiny of the peer-review process, as would any other study.  To-date,  the most valid in vivo studies done have failed to find conclusive evidence of a physiologic mechanism.  A meta analysis of such studies by Verschaeve, et al, (2010) concluded that "Many of the positive studies may well be due to thermal exposures, but a few studies suggest that biological effects can be seen at low levels of exposure. Overall, however, the evidence for low-level genotoxic effects is very weak."

Epidemiological Approaches

In the absence of conclusive in vivo studies it becomes a question of who can produce a valid epidemiological study.  One of the most often-cited studies, to-date attempted to correlate the incidence rates of gliomas and meningioma (brain cancers) with rates of cell phone use in Denmark, Finland, Norway, and Sweden from 1974–2003 (Deltour, 2009) based on over 58,000 cases of brain cancer.  The authors concluded that "The lack of a detectable trend change in incidence rates up to 2003 in this study suggests that the induction period for brain tumors associated with mobile phone use exceeds 5–10 years, that the increased risk of brain tumors associated with mobile phone use in this population is too small to be observed, that the risk is restricted to subgroups of brain tumors or mobile phone users, or there is no increased risk associated with mobile phone use. "

Responsible Health Communications

My concern is that by the very nature of their being made, comments by WHO regarding the need for more research intentionally or unintentionally communicates to the public that not enough research is being done.  In reality, much research  *is* currently underway, such as the 'Cosmos' study, which is a large-scale prospective cohort study of mobile telephone users (250,000 men and women aged 18+ years in five European countries - Denmark, Finland, Sweden, The Netherlands, UK), followed over 25 years (Schüz J, et al, 2010).

Media coverage

Although I am reserving judgment until WHO releases their monograph, organizations such as the World Health Organization have a particular obligation to follow evidence-based guidelines and to recognize the effects that their communications have on public perceptions and health behaviors . Although one might argue that the WHO working group is simply calling for more research, a strong argument can be made that such research is and has already been underway, making their call seem more like an unnecessary and alarmist call to action.  Given that media outlets are in the business as maximizing readership with compelling stories, it was no surprise to see the numerous dramatic headlines in today's (June 1) news, such as:

• WHO: Cell phone use can increase possible cancer risk CNN. com
• Cellphones, cancer: Study links cellphones to possible cancer risk
• Cellphones may cause cancer, international agency says - NYPOST.com
• Cellphones Possibly Cause Cancer, WHO Warns

Pronouncements such  as this one remind me as a quote I often share with public health students by Harvard epidemiologist, Dr. Walter Willet during an interview with Science Watch:

Interviewer: The science of risk-factor epidemiology is controversial these days because of what people call the "carcinogen" or "anxiety-of-the-week syndrome." It seems that every week the newspapers carry a new and usually contradictory study telling us what we should or should not eat. Is this our imagination, or is there really a problem? 

Willett: It's true; there is a problem. Part of it is this very direct link between ongoing work and what comes out in The New York Times. The natural course of science is that people do studies and report finding something, but nobody believes it too much-and, hopefully, neither do the investigators-until it's reproduced by other researchers. But in the meantime, it's on the front page of the newspaper. So there is this tendency for the least substantiated findings to be the ones coming out in the popular press, when in fact this is simply part of the scientific process, and a lot of suspected associations are not ready for the public to take action or even worry about.

Sources

L. Verschaeve a,*,1, J. Juutilainen b,1, I. Lagroye c,1, J. Miyakoshi d,1, R. Saunders e,1, R. de Seze f,1,T. Tenforde g,1, E. van Rongen h,1, B. Veyret c,1, Z. Xui,1. (2010).  In vitro and in vivo genotoxicity of radiofrequency fields. Mutation Research 705 (2010) 252–268

Schüz J, Elliott P, Auvinen A, Kromhout H, Poulsen AH, Johansen C, Olsen JH, Hillert L, Feychting M, Fremling K, Toledano M, Heinävaara S, Slottje P, Vermeulen R, Ahlbom A. (2010).  Cancer Epidemiol. 2011 Feb;35(1):37-43. An international prospective cohort study of mobile phone users and health (Cosmos): design considerations and enrolment. Cancer Epidemiol. 2011 Feb;35(1):37-43.

 Deltour, (2009). Isabelle Deltour, Christoffer Johansen, Anssi Auvinen, Maria Feychting, Lars Klaeboe and Joachim Schüz . Time Trends in Brain Tumor Incidence Rates in Denmark, Finland, Norway, and Sweden, 1974–2003. JNCI J Natl Cancer Inst (2009) 101 (24): 1721-1724. doi: 10.1093/jnci/djp415