*Update: See Michael Shermer and Bernard Leikind’s post in eSkeptic this week. They are responding to the boat-load of email they received about their articles in Scientific American and Skeptic magazine concerning the lack of evidence to cancer to cell phone use.*
On Monday, we published the first half of a critique of a new book by Dr. Devra Davis: Disconnect: The Truth About Cell Phone Radiation, What the Industry Has Done to Hide it, and How to Protect Your Family. This is the second half of the critique.
Part II: Cell Phones and Cancer
The “fine print”
Davis devotes an entire chapter to the so called “warnings” in “fine print” in the user manuals for cell phones. On P. 217 she says: “The HTC Droid Eris cell phone from Verizon contains a Product Safety and Warranty Information booklet. On page 11 it is recommended that no part of the human body be allowed to come too close to the antenna during operation of the equipment….To comply with RF exposure requirements, a minimum separation distance of 1.5 cm must be maintained between the users body and the handset”. Davis further states: “A reader might think it was just a matter of complying with a silly rule that government had produced.”
Well yes actually, such a procedure is called for in government regulations (FCC OET Bulletin 65 Supplement C, IEEE Standard 1528 and IEC 62209-1). When cell phones were first developed, they were quite bulky and could not fit into a shirt pocket. They were often carried in a holster and were always used with the phone held to the ear. The original testing standards were written at that time to reflect this. Today’s ultra slim iPhones and Blackberries can be carried in a shirt pocket – much closer to the body. They are tested and comply with SAR limits when held to the ear (or pinna in technical jargon). However, if the phone is used while near body such as in your shirt pocket, the SAR limit may be exceeded if it is closer than the required test distance of 15 to 25 mm. This is not considered to be a safety issue, since the SAR limit has a 50X safety margin (according to the new IEEE C95.1-2005). It is a technical compliance issue.
Davis implies that cell phone companies have included these “fine print” warnings as a potential defense in liability lawsuits from brain cancer patients. There is no record of this “defense” ever having been used in any of current liability suits and none of these lawsuits has yet succeeded. The separation distance is for body worn and not for the head position and therefore is irrelevant to brain cancer.
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 53,204 (42,549 for 10 – 14 years, 10,655 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.
Dr. Lorne Trottier. is an electronics engineer, a co-founder of Matrox a major hi-tech company. He is President of the Foundation of the Montreal Science Center, and has an honorary doctorate from McGill University. He has spent considerable time (with colleagues from McGill) putting together the web site www.emfandhealth.com which contains a wealth of information and credible scientific references on the issue of EMF and health. Included on the web site are references to statements from most of the world’s public health organizations attesting to the fact that there is no credible scientific evidence that EMF causes health effects. Dr. Trottier is a member of the CFI Canada board and a science adviser to the Committee for the Advancement of Scientific Skepticism (CASS) at the Centre for Inquiry Canada.
Harvey Kofsky is a Professional Engineer. He has a BaSC degree in 1966 in electrical engineering from the University of Toronto. He is an entrepreneur who has founded a number of successful electronics companies including Promatek Industries Ltd. during his career. Kofsky is passionate about ensuring that the public is given appropriate information in order to evaluate pseudo scientific media reports.
- WHO. Electromagnetic Fields and Public Health: Mobile Phoneshttp://www.who.int/mediacentre/factsheets/fs193/en/index.html
- WHO. About Electromagnetic Fields http://www.who.int/peh-emf/about/en/
- American Cancer Society Cellular Phoneshttp://www.cancer.org/Cancer/CancerCauses/OtherCarcinogens/AtHome/cellular-phones
- Health Canada. Safety of Cell Phones and Cell Phone Towers http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/prod/cell-eng.php
- European Commission. Health Effects of Exposure to EMF. Opinion of the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR)http://ec.europa.eu/health/ph_risk/committees/04_scenihr/docs/scenihr_o_022.pdf
- Statistical tools used to identify scientific misconduct in mobile phone research (REFLEX program)Alexander Lerchl, Adalbert FX Wilhelm http://arxiv.org/abs/0807.2554
- 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; 2007http://www.ncbi.nlm.nih.gov/pubmed/16997616
- 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. http://www.fertstert.org/article/S0015-0282%2807%2900332-9/abstract
- 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)http://onlinelibrary.wiley.com/doi/10.1002/bem.10083/abstracthttp://onlinelibrary.wiley.com/doi/10.1002/bem.10083/pdf
- The Lack of Histological Changes of CDMA Cellular Phone-Based Radio Frequency on Rat Testis, Lee et al. Bioelectromagnetics 31:528^534 (2010) http://onlinelibrary.wiley.com/doi/10.1002/bem.20589/abstract
- 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 http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1634754
- 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 http://ije.oxfordjournals.org/content/39/3/675.full.pdf
- 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 http://jnci.oxfordjournals.org/content/98/23/1707.full
- 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) http://thejns.org/doi/abs/10.3171/foc.2006.20.4.E1?prevSearch=allfield%253A%2528Deorah%2529&searchHistoryKey=
- Analysis of trends in incidence rate of brain tumors from 1992-2006 in U.S., Inskip et al. Neuro Oncol 12(11):1087 (2010) http://neuro-oncology.oxfordjournals.org/content/12/11/1147.abstract?sid=a27c5433-bb37-464f-8f8d-5130bb55b69a
- 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) http://www.ncbi.nlm.nih.gov/pubmed/17220708
- 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. http://jnci.oxfordjournals.org/content/101/24/1721.abstract?sid=776da054-2ba3-4894-9b15-a181bc786a4c