Thursday, September 3, 2015

On Wi-Fi in Schools and the Precautionary Principle

I knew this day was coming. I wasn’t sure when, but I knew that at some point as a promoter of evidence-based decision-making I would have to take on the topic of Wi-Fi in schools at this blog. Well the new school year is here and the topic has started to bubble up to the surface in the local press and I have been asked to comment on it. Right off the top I want readers to know that this blog post will not go into detail about the research. I will provide links to lots of resources but want to look at this topic from a policy perspective, with a special emphasis on how the Precautionary Principle is misused in activist arguments.
Let's start with a common misconception; Wi-Fi is not a new technology. Rather, Wi-Fi is a new twist on an old technology: transmitting information via the radiofrequency (RF). Humans have been broadcasting radio and microwave transmissions across the planet for over a century.
As for health studies, according to the World Health Organization, over the past 30 years approximately 25,000 articles have been published on the biological effects and medical applications of non-ionizing radiation. RF is just another form of non-ionizing radiation.
If you are looking for detailed discussions about the science behind RF and cancer then there are a lot of good resources out there. The U.S. National Cancer Institute has a very good Question and Answers page, Health Canada has a Frequently Asked Questions page and the BC Center for Disease Control has a radiofrequency toolkit that everyone reading on the topic should look at.
As for the peer-reviewed science, the United Kingdom Advisory Group on Non-Ionising Radiation (AGNIR) put out a hefty report in 2012 that is worth a read if you have time to digest 300+ pages of detailed discussion and references on the topic. A very readable discussion of the topic of Wi-Fi activism in Canada was conducted by Bad Science Watch and further Canadian resources include Skeptic North’s take on the issue. As for Wi-Fi in schools and public places well Skeptic Blog has a good summary and Health Canada a good video on the topic.
Anti-Wi-Fi activists will point out that the International Agency for Research on Cancer (IARC) investigated radiofrequency electromagnetic fields as possibly carcinogenic to humans. The IARC Monograph on the Evaluation of Carcinogenic Risks to Humans provides a comprehensive examination of the topic and the IARC classified radiofrequency electromagnetic fields as a Group 2B possible carcinogen. The critical thing to understand is that Group 2B compounds are, by their very definition, not known to be carcinogens.
Group 2B is a category used when a causal association looks like it might be possible, but when other factors cannot be ruled out with reasonable confidence. Group 2B is, thus, a placeholder for compounds that haven't been shown to cause cancer but are of further interest for study. Some of these compounds, like acetaldehyde and benz[a]anthracene, will likely be determined to cause cancer but others like coffee, pickled vegetables and talc-based body powder, are much less likely to do so. My opinion, based on a mountain of peer-reviewed research, is that radiofrequency electromagnetic fields will be in the latter group and not the former.
I briefly mentioned Wi-Fi on Twitter yesterday and immediately an activist brought out their big gun: The BioInitiative Report. This report is very official-sounding but it has been debunked and discounted by every scientific body that has looked at it, from Australia to the European Union. The EMF & Health website has a whole section dedicated to it. I mentioned this fact and got directed to a single study that indicates the possibility that RF can cause a particular type of cancer. That study didn’t really bother me either.
Scientific research uses as its gold standard the 95% confidence interval (p<0.05). What this means is that if you replicate a study 100 times about five of the tries will give you a false positive (saying that a compound causes an effect when it really does not). Given the approximately 25,000 articles published on the topic, the absence of any toxicologically negative outcomes is statistically improbable.
What is important is to look at the number of positive studies when compared to negative ones. Moreover, a careful examination of the handful of positive studies shows that almost every one involved a particularly rare type of cancer and a minimal effect. This is the ideal scenario for a false positive. Population statistics break down when sample sizes are small and in the cases of most of these studies the number of affected individuals is tiny with respect to the general population. As I pointed out above, there is a copious body of literature that says that Wi-Fi is safe.
To back up that copious body of literature consider that from an epidemiological perspective we have been engaged in a massive human test trial for the last 70+ years. From radar operators during the Second World War to children with cell phones in 2015, billions of humans world-wide have been exposed to varying concentrations and doses of microwave and radio wave radiation. Just look at your cell phone right now, almost anywhere you go you are in range of a Wi-Fi router and you are almost always in range of a radio signal. The fact is, we have not seen spikes in any of those rare cancers purportedly related, via these questionable studies, to exposure to RF.
Certainly we hear about a single police officer here or a woman there who got a suspicious cancer but as I point out in my post Risk Assessment Epilogue: Have a bad case of Anecdotes? Better call an Epidemiologist that is why we have epidemiologists. Epidemiologists look at all the anecdotes and see if there is some underlying trend. The results are categorical: RF is not a serious human health risk. Rather, it is almost a perfect example a de minimis risk (which I discuss in another blog post How Big and Small Numbers Influence Science Communication Part 2: Understanding de minimis risk). As I point out in that blog posting a de minimis risk is a risk that, while it may exist, is too small to be of societal concern.
So how does an activist try and sell you on making a societal change when dealing with a de minimis risk? The answer is almost always: the Precautionary Principle. Activists use the Precautionary Principle because it sounds good and most people don’t actually know what it says. In a previous post How Big and Small Numbers Influence Science Communication Part 3: Understanding "Acceptable" Risk I introduced readers to the real definition of the Precautionary Principle. The actual Precautionary Principle was defined as Principle 15 in the Rio Declaration which states:
"In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.”
The Precautionary Principle does not say that all risk is bad risk and that all risks must be avoided because that is not a realistic way to run a society. Getting out of bed in the morning poses a non-zero risk of slipping and breaking your neck. Using the Wi-Fi activist view of the Precautionary Principle we would have to ban all beds to avoid that potentially fatal risk. Instead of requiring “no risk” in the real world we ask: what is an “acceptable risk”?
As I have written previously since we live every day in a world full of risk, we need to figure out how to deal with and understand the risk. That is why we (Canadians) hire epidemiologists and other scientists at places like Health Canada: to help us understand and differentiate between acceptable and unacceptable risks. The reason smart meters, Wi-Fi and cell phones are of little concern to Health Canada is that these technologies are not some mysterious things for which the Precautionary Principle may apply. Transmitting information on the microwaves spectrum is a mature technology that we have used for almost 100 years. The Precautionary Principle does not apply because we have almost 25,000 scientific studies that each individually say that RF exposure is probably safe; but when you repeat that “probably” 25,000 times what it really means is that you are safe.
The Precautionary Principle also considers the consequences of actions. In the case of W-Fi in schools you have a real and obvious benefit. Students with access to Wi-Fi have access to more teaching resources and a better education experience than students without. If you want to eliminate Wi-Fi in the classroom you either accept that you are going to give your kids a lower standard education or you have to hardwire every classroom in every school. The hardwiring of schools is often thrown out as if it were a viable alternative, but the costs of hardwiring every classroom in British Columbia are simply unaffordable. Moreover, it is not as if the schools are RF-free zones to begin with. An informative report on CTV demonstrated quite categorically that schools without Wi-Fi set-ups can have higher levels of Wi-Fi running through them than schools with Wi-Fi. Heck any parent who has attended a Christmas concert in their kids gym knows that they can typically find a at least a dozen Wi-Fi networks on their cell phones.
So to respond to the obvious activist rebuttals to this piece: Wi-Fi is not some brand new technology that we must fear, it is simply a new spin on an old technology. Wi-Fi is not a carcinogen, rather after 25,000 studies on the RF spectrum and its effect on humans and after the exposure of billions of humans to RF the best scientists can say is that it might be responsible for a handful of rare cancers. If RF is a cancer risk, it is one below the de minimis threshold: one that may exist but is too small to be of societal concern. As for applying the Precautionary Principle, that is just a red herring. The Precautionary Principle does not say that you accept no risk only that you factor risk and rewards into your calculations and in this case the risks are negligible and the rewards significant. Applying the Precautionary Principal it is an easy call to keep Wi-Fi in the classrooms.

1 comment:

  1. The reason anti-Wifi activists target schools is that is where the Precautionary Principle means "Think of the Children".

    People will often take risks themselves, yet go beserk when schools allow the same risks to be taken with their children. Adult sports teams just order a bus and get on it if they need to go to an away game, but children's teams need all the risks outlined and specific permissions given. Adults are expected to be able to manage their own medications, but even 17 year old children are apparently unable to say what their allergies are, and have to have everything on file carted with them when they travel.

    I think you ought to also mention that no mechanism is known to exist whereby EMF can cause cancers, other than possibly skin cancers. It's not just that no studies show that cancer is caused, it is that people have looked hard to see how EMF could conceivably cause cancer and not been able to do that.