A new alarmist book about cell phones
by Devra Davis
Interphone & cell phone use for 10+ years
Davis only discusses a handful of the thousands of studies that find no harm from either EMF or cell phones. She gets some critical facts about these studies completely wrong. A prime example is the claim by Davis that all studies that have looked at cell phone use for a period of more than 10 years have found an increased risk of brain cancer. P 193 "But when you look at those few studies that included people who had used phones for a decade or more, the results show that heavy cell phone use causes brain tumors. If you consider all of the studies that have been published, most of them have not followed people for a decade. But if you examine only those studies that have analyzed people for a decade or longer you find one thing: Every single one of them shows that long-term heavy use of cell phones has increased the risks of brain tumors".
This is totally false; several important studies find no harm. All of the studies that Davis refers to are so called "case control" studies. These types of studies are considered much less reliable because they depend on memory to assess past exposure. People diagnosed with brain cancer and healthy controls respond to a questionnaire in which they are asked to remember how much they used their cell phones. Recall is known to yield different estimates than actual phone records. In addition, because people who have had cancer have heard about the potential link to cell phones, they are more likely to err by reporting higher exposure than controls. Therefore such studies are subject to a limitation called "recall bias". Davis does not even mention this key weakness.
Most of the "10 year plus" studies that Davis refers to were the work of a single Swedish researcher, Dr. Lennart Hardell. His methods have been widely criticized. Most of the others were components of the Interphone study (* 12). Some of the individual components of Interphone were released prior to the final comprehensive report. Contrary to Davis' claim, not all of these found increased cancer risk for 10+ years. The final conclusion of the Interphone study is important: "Overall, no increase in risk of glioma or meningioma was observed with use of mobile phones. There were suggestions of an increased risk of glioma at the highest exposure levels, but biases and error prevent a causal interpretation. The possible effects of long-term heavy use of mobile phones require further investigation." In the text, the authors discuss the considerable evidence for recall bias that they found during the study. The overall conclusion of "no increase in risk" is the key finding.
Misstating Key Danish cell phone study
One of the most important studies on cell phones was a Danish study of 420,000 cell phone users (*13). It was a "cohort study", not a "case control" study. Exposure was assessed based entirely on actual cell phone records. It also used actual medical records to verify the diagnosis. Such studies do not suffer from any "recall bias". Because it is based on objective data, it carries much more weight than case control studies. While this particular study has other possible limitations, it is one of the few that is based on actual hard data.
Davis gets most of the major facts about this key study completely wrong. For example on Page 193 she says it "included only two cases that had used a phone for a decade". The real number of users for a decade or more was 56,648 (42,549 male + 3131 female for 10 - 14 years, 10,655 male + 313 female for 15 - 21) years. No increase in brain cancer or any other illness was reported for any class of cell phone users including the long term users.
On P 182 She says: "All of us have cell phone bills that provide detailed records of our use; and most of these can be accessed online. These were not used in this study, or in any study of the industry to date". This is also false. In the U.S. this information is private and confidential and to date has not been available to interested researchers. The Danish study used cell phone records to establish the number of years of use of a cell phone for each of the 420,000 individuals in the study. The authors obtained the approval of the required Danish government agencies such as the Danish Data Protection Board to protect the privacy of the information. The study was entirely based on record linkage.
Brain cancer trends & her "unpublished" result
Another example of a major falsehood in the book is the section she calls "My Unpublished Result". She says: "Papers showing no increase in the overall brain cancer rate adjusted to the entire population have been published, while those taking a more sophisticated look at growing rates of brain tumors in young persons remain under review". Davis claims she has unpublished results showing brain cancer is increasing in young adults. Technically these time trend data may have limitations. For example, in the 70's and mid 80's new technology led to apparent increased "rates" of brain cancer, due to better diagnostic equipment.
However, since the mid 80's, which happens to coincide with the introduction of cell phones, overall brain cancer incidence rates have been constant. Contrary to what Davis claims, at least 4 studies (* 14, 15, 16, 17) have been published for brain cancer by age group. None shows any significant increase for any age or sex group that can be linked to cell phones. For example, another Danish study (* 17) looked at incidence rates by age group in 5 Northern European countries. No significant change in brain cancer rates were found for any age group. A recent US study came to a similar conclusion (* 15). In science, "unpublished results" rank lower that self published articles, which are at least published.
Brain cancer is one of the rarest forms of cancer. For example it ranks at #15 in Canada. There are more that 4 billion cell phones in use worldwide. The absence of any change in the incidence of brain cancer is the simplest evidence against any connection with cell phones. Davis' mangled commentary on these brain cancer studies are the most blatant examples of the many misstatements in Disconnect. There are simply too many to cover all of them here.
Davis and other EMF alarmists are attempting to do an end run around the mainstream scientists responsible for public health standards. They even have their own self appointed organization with the impressive sounding name: International Commission for Electromagnetic Safety (ICEMS). The goal of alarmists is to scare enough members of the public about the dangers of EMF in order to sway politicians to do their bidding. Davis was one of the organizers of a conference held in Washington, DC on Sept. 15, 2009 timed to coincide with Senate hearings on cell phone safety. Such tactics have already achieved some "success" in Europe and a few other countries where politicians have ignored the advice of their own scientists to impose new restrictions on EMF.
Disconnect is a good example of the kind of material used by the EMF alarmist movement. It is highly selective and totally biased in discussing only studies that support its point of view, it rejects contrary studies accepted by the majority of mainstream scientists as the product of some vast conspiracy, and it completely misstates the findings of key studies that find no harm from cell phones. It is at odds with the conclusions of mainstream expert groups such as the SCENHIR (* 5 P 8): "It is concluded from three independent lines of evidence (epidemiological, animal and in vitro studies) that exposure to RF fields is unlikely to lead to an increase in cancer in humans". Disconnect is designed to bamboozle and scare the lay reader, not to inform.
1. WHO. Electromagnetic Fields and Public Health: Mobile Phones
2. WHO. About Electromagnetic Fields
3. American Cancer Society: Cellular Phones
4. Health Canada. Safety of Cell Phones and Cell Phone Towers
5. European Commission. Health Effects of Exposure to EMF. Opinion of the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR)
6. Statistical tools used to identify scientific misconduct in mobile phone research (REFLEX program) Lerchl et al.
7. Genotoxic effects of exposure to radiofrequency electromagnetic fields (RF-EMF) in cultured mammalian cells are not independently reproducible, Speit et al. Mut Res 626:42- 47; 2007
8. Effect of cell phone usage on semen analysis in men attending infertility clinic: an observational study, Agarwal et al. Fertil Steril 2008; 89:124-8.
9. Whole Body Exposure of Rats to Microwaves Emitted From a Cell Phone Does Not Affect the Testes, Dasdag et al. Bioelectromagnetics 24:182^188 (2003)
10. The Lack of Histological Changes of CDMA Cellular Phone-Based Radio Frequency on Rat Testis, Lee et al. Bioelectromagnetics 31:528^534 (2010)
11. Comparisons of Computed Mobile Phone Induced SAR in the SAM Phantom to That in Anatomically Correct Models of the Human Head, Beard et al. IEEE Trans. Electro Comp, Vol. 48, No. 2, May 2006
12. Interphone Study Goup: Brain tumour risk in relation to mobile telephone use: results of the INTERPHONE international case-control study. Cardis et al. International Journal of Epidemiology 2010;39:675-694
13. Cellular Telephone Use and Cancer Risk: Update of a Nationwide Danish Cohort, Schüz et al. JNCI J Natl Cancer Inst (6 December 2006) 98 (23): 1707-1713
14. Trends in brain cancer incidence and survival in the U.S.: Surveillance, Epidemiology, and End Results Program, 1973 to 2001, Deorah et al. Neurosurg Focus 20:1 (2006)
15. Analysis of trends in incidence rate of brain tumors from 1992-2006 in U.S., Inskip et al. Neuro Oncol 12(11):1087 (2010)
16. Cellular telephone use and time trends in brain tumour mortality in Switzerland from 1969 to 2002, Roosli et al. Eur J Cancer Prev. 16:77 (2007)
17. Time Trends in Brain Tumor Incidence Rates in Denmark, Finland, Norway, and Sweden, 1974-2003, J Natl Cancer Inst. 2009 Dec 16;101(24):1721-4.
Except where noted all images on this web site are taken from the Wikipedia commons
All trademarks are the property of their respective owners Copyright 2009 EMF & Health