Since my last entry on WiFi was a lightning rod for the fringe, I decided I would provide a bit of a rebuttal and an update on the challenges to the public sector on the provision of WiFi and cell phone towers. Below are many of the charges levied agains cell phones and their infrastructure, as well as WiFi and the scientific consensus so far on the issue, as provided by the panel of scientific experts that we have access to at CASS and CFI Canada. Terms can be confusing, and there are many different ones used. I will stick to using cell phones and WiFi as often as possible, but the term “radio frequencies” or RF may be used as a substitute. In this post, the major claims, with tomorrow’s covering the precautionary principle and the weight of evidence approach. Onward Friday to the petitions being launched in several jurisdictions in Canada to limit the installation of WiFi in libraries and cell phone towers in towns, as well as a roundup of a few of the interesting studies coming out in the last few months. Phew, it has been a while…
Microwave Radiation Causes Cancer
Skeptics and scientists everywhere keep making the point that the RF from wireless communications, specifically those in the 800 MHz to 3000 MHz range, do not have enough energy to break bonds and therefore cannot cause direct DNA damage and cancer. This remains true. However, this was not the argument that most of the WiFi fringe was making and it was a poor choice to keeping harping on this. This topic is still a moving target, and just this week the World Health Organization’s International Agency for Research into Cancer (IARC) did yet another review of the evidence, and officially classed the radiation from cell phones as 2B, concluding 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.”
Group 2B is defined by the IARC as follows:
“Group 2B: The agent is possibly carcinogenic to humans. This category is used for agents for which there is limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals. It may also be used when there is inadequate evidence of carcinogenicity in humans but there is sufficient evidence of carcinogenicity in experimental animals. In some instances, an agent for which there is inadequate evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals together with supporting evidence from mechanistic and other relevant data may be placed in this group. An agent may be classified in this category solely on the basis of strong evidence from mechanistic and other relevant data.”
Sounds scary, right? However, other examples of class 2B substances or activities from the same list include: coffee, orange oil (clean a counter, lately?), talc (when used in the peritoneal area, or that place down below), pickled vegetables (apparently only in Asia) and, yes, carpentry and joinery. The folks from Cancer Research UK interpret this as follows:
“Group 2B – this is the one that mobile phones now fall under – means something is “possibly carcinogenic to humans”. It means there is “limited evidence” that something causes cancer in people, and even the evidence from animal studies is “less than sufficient”. Group 2B means that there is some evidence for a risk but it’s not that convincing. This group ends up being a bit of a catch-all category, and includes everything from carpentry to chloroform.”
So perhaps the overblown media scare that will result in this announcement can be tempered with the thought that you run similar risks when you get up, have a cup of coffee, powder yourself and go down to the woodshop to turn a table leg. Here is a quick round up of the big studies, from NPR. This is also not the first time a review has been done. The members of an CFI ad hoc group formed as a result of the debate are still very skeptical of the WHO’s results. They would echo the conclusions of the European Union’s Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) in their report on the effects of radio frequency emissions after an extensive review of the literature:
“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.”
One of the members of our WiFi “privy council”, Dr. Bezad Elahi, a CASS member and an MD pursuing his PhD from University of Toronto in neuroscience, had this to say:
“Both case control and cohort studies provide epidemiologic evidence that cellular telephone use does not have a large effect on the incidence of brain tumors and here is the evidence.”
- Inskip PD, 2001 Cellular-telephone use and brain tumors.
- Schuz J, Jacobsen R, 2006 Cellular telephone use and cancer risk: update of a nationwide Danish cohort.
- Muscat JE, Handheld cellular telephone use and risk of brain cancer.
- Christensen HC, 2004 Cellular telephone use and risk of acoustic neuroma.
- LynnS, 2005 Long-term mobile phone use and brain tumor risk.
- Am J Epidemiol. 2006, Cellular phones, cordless phones, and the risks of glioma and meningioma (Interphone Study Group, Germany).
Dr. Elahi makes a good point. Given the difficult time we have had showing a link between cell phone use and cancer, the increased risk, if there is indeed one, is probably so small to not be something to worry about. Another important point here is that this research concerns a cell phone placed to the head, with the antenna placed in close proximity to the brain. The strength of the signal from a wireless router is 1/10th that of a cell phone, and is often several meters or tens of meters away from a person in the average household, so the amount of radiation, decreasing exponentially by the inverse square law, is infinitesimal compared to a regular cell phone, which is already much lower than the phones from 10-15 years ago. For those of you in the know, this leads to a banana equivalent dose (BED) of close to zero, or according to this Guardian article a one year exposure in a classroom is equal to a 20 minute cell phone call (keeping in mind that the cancers studies focused on heavy users who spoke 30 mins or greater a day on their cell phones.)
The Council of Europe announced this week, prior to the WHO report, that they were recommending caution with cell phone use adn that the standards should even be lowered. It is not inconceivable that they saw the WHO report coming but their recommendation comes without any data to support it. That decision was appropriately critiqued on Ars Technca the same day.
So I can conclude from this discussion that cell phones and WiFi are unlikely to cause cancer but it is still possible there may be a cancer link. More research is need for sure, and our opinion may evolve over time, however, this charge is often conflated with more subtle effects that are said to change brain function through other means.
Subtler Forms of Interaction with Neuronal Tissue
The less direct approach by those mongering fear was to assert that over time, exposure to cell phones or WiFi could affect the nervous system and cause other less life-threatening, but distressing symptoms, like fatigue, or a “brain fog,” or interfere with the normal functioning of the brain. No effect has been shown to consistently exist so far, and all effects on tissue are considered to be due to heating. The microwaves do not break bonds, they just make water and other similar sized molecules jiggle just a bit more, causing a buildup of heat. From The International Commission on Non-Ionizing Radiation Protection (ICNIRP), who recently conducted an in depth study on all of the science surrounding RF ( p. 260):
“The mechanisms by which RF exposure heats biological tissue are well understood and the most marked and consistent effect of RF exposure is that of heating, resulting in a number of heat-related physiological and pathological responses in human subjects and laboratory animals. Heating also remains a potential confounder in in vitro studies and may account for some of the positive effects reported”
“Recent concern has been more with exposure to the lower level RF radiation characteristic of mobile phone use. Whilst it is in principle impossible to disprove the possible existence of non-thermal interactions, the plausibility of various non-thermal mechanisms that have been proposed is very low”.
And from CASS advisor and Senior Medical Physicist and Assistant Professor, Dept. of Oncology, University of Alberta, Marc Mackenzie:
“With non-ionizing radiation you can get a heating effect. Health agencies (Health Canada, FDA) limit the Specific Absorption Rate (SAR) to < 1.6 W/kg (2 W/kg in the EU), which is enough energy to heat water by 0.0004 C per s or 0.024 C per minute. While that’s enough to heat tissue 0.72 C in 30 minutes, try jogging on the spot for a minute. You’ll be generating far more heat, and your body is very well equipped to deal with excess heat generated”
The Royal Society of Canada hedged its bets a bit but produced this updated statement on EMF in 2009:
“At present, the results from epidemiologic studies do not provide sufficient evidence to support a clear association between mobile phone use and an increased risk of head and neck benign tumors… Animal carcinogenesis studies conducted to date (Table 2) provide no convincing evidence that nonthermal RF field exposures either cause or contribute to cancer, although some studies suggest the possibility for low-level exposures to increase the risk of cancer.”
So, RF will not ionize, there is little evidence of increased cancer risk and the heat is negligible. That only leaves one more health claim.
This is the most dubious claim, but despite the obvious parallels to anxiety disorders it continues to be a constant refrain for those promoting the limitation of WiFi in public spaces (again, conflating the evidence from a cell phone antenna held against the head and a WiFi source tens or hundreds of meters away.) Despite Magda Havas’s assertions (see section 4,) the World Health Organization is pretty unequivocal about the reality of electro-hypersensitivity:
“EHS is characterized by a variety of non-specific symptoms that differ from individual to individual. The symptoms are certainly real and can vary widely in their severity. Whatever its cause, EHS can be a disabling problem for the affected individual. EHS has no clear diagnostic criteria and there is no scientific basis to link EHS symptoms to EMF exposure. Further, EHS is not a medical diagnosis, nor is it clear that it represents a single medical problem.”
But don’t take their word for it, here is the conclusion from the review of EHS studies done by Rubin et al in 2009 (IEI-EMF is short for Idiopathic Environmental Intolerance attributed to electromagnetic fields, formerly electro-hypersensitivity):
“No robust evidence could be found to support this theory. However, the studies included in the review did support the role of the nocebo effect in triggering acute symptoms in IEI-EMF sufferers. Despite the conviction of IEI-EMF sufferers that their symptoms are triggered by exposure to electromagnetic fields, repeated experiments have been unable to replicate this phenomenon under controlled conditions.”
I am convinced that EHS is a manifestation of an anxiety disorder, which can exacerbate other problems, and lead to heart palpitations, chest pain, sleep disorders, fatigue and cloudy thinking; all the more reason to use the precautionary principle – but apply it correctly.
Tomorrow, the precautionary approach and the weight of evidence: red herrings of doubt.
pics above via FreeFoto and Creative Commons Licence by Ian Britton