The Precautionary Principle
In many discussions of the “dangers” of WiFi and cell phones, the precautionary principle is evoked. It is the idea that we have “an obligation, if the level of harm may be high, for action to prevent or minimise such harm even when the absence of scientific certainty makes it difficult to predict the likelihood of harm occurring, or the level of harm should it occur.” It is important to note that the precautionary principle or approach is required when we do not have a scientific consensus or if we have a lack of scientific certainty. It is used often in European regulation of potential health and environmental hazards. “Scientific certainty” is an important clause here, because it does not mean 100% certainty. Science can never give that absolute a result and if we required 100% certainty of no risk, we would not walk out our front doors or even get out of bed, lest we have a mishap.
The proper application of the precautionary approach depends, of course, on the solutions and precautions being offered. The IARC of the WHO mentioned yesterday suggests that cell phone exposure should be limited for those under 16 and adults should choose hands-free devices when possible. On the surface, that sounds logical. However, given that there is little if any evidence of harm and that the WHO, as detailed by Ed Yong in the Cancer Research UK blog, had to put cell phone radiation in the 2b category because it could not rule out a possibility of an increased risk, these restrictions are jumping the gun. When the uncertainty is exceedingly small, precaution seems unnecessary.
However, going one step further and making the same claims about WiFi, which is, in practice orders of magnitude below the exposure level of a cell phone, is downright ridiculous. A fair analogy would be coffee, which is the same class 2b as cell phone radiation. Extending the caution to WiFi would be like extending the warning about coffee to smelling the freshly ground beans.
This has not stopped the Ontario* New Democratic Party (full disclosure: I am a member) from calling for warning labels to be place on cell phones and other related devices. I know what is going on here: many, many well-meaning individuals are afraid of missing the next “cigarette smoking” type of threat and they are being overly cautious because of the political and perceived health price that might be paid. This fear, given the weak epidemiological evidence and no mechanism of injury suggested anywhere in the literature, is unfounded.
On popular gambit of the fringe is to suggest that a manufacture cannot market their product until they have proven that the product is harmless. This is, by definition, attempting to prove a negative; an impossible standard to hold a manufacture to. Everyone wants to use safe products, and I am not suggesting (the proper socialist that I am, see above) that government regulation places an undue burden on the poor manufacturer, but it is also unfair to place impossible restrictions on a manufacturer that make them responsible for ensuring that every conceivable harm that may be perpetrated by or with their product must be eliminated before they are allowed to sell it. I am thinking of a hammer manufacturer responsible for ensuring its customers do not injure their thumbs or being forced to render the tool impervious for use as a weapon. As was suggested by the judge in the case of Sanchez vs the Department of Energy in which it was suggested that the Large Hadron Collider could produce a black hole and swallow the entire earth:
“Injury in fact requires some “credible threat of harm…. At most, Wagner has alleged that experiments at the Large Hadron Collider (the “Collider”) have “potential adverse consequences.” Speculative fear of future harm does not constitute an injury in fact sufficient to confer standing”
“Speculative fear of future harm,” hmm, sounds familiar.
The straw men of cigarette smoke, thalidomide, acid rain and even global warming are often evoked as parables of caution in our approach to cell phone and WiFi use, but we should be careful when considering them as such. Tobacco was shown to be directly and clearly harmful in animal studies and epidemiological studies as early as the 1930’s and by the 60’s and 70’s surgeons general were speaking out against the harms of tobacco. The implied message that is being sent by those who compare WiFi with smoking is that there is an active campaign of suppression by pro-RF supporters that is industry funded and led in order to discredit clear scientific evidence of harm. There may be a conspiracy, but proof of one, beyond speculation, is never offered and there is no long history, like there is of smoking, to suggest that there is a clear link between low level RF from wireless devices and any human health problem
As far as the red herrings of thalidomide, acid rain, and global warming go, scientists have been on the forefront of warning the public about the dangers of these issues. Thalidomide was the catalyst for the development of the modern drug approval process that forced the drug manufacturers to prove safety and efficacy of their product and demanded post-approval follow up trials that have caught things like the Vioxx scandal. These problems are examples of the scientific method of investigation working, but because proponents of dirty electricity have made their mind up prior to looking at the evidence they ignore the same mainstream science that proved acid rain and global warming to be a threat while failing to find any problem with EMF and RF.
The precautionary approach is fine when dealing with a certain level of uncertainty, but make no mistake, the uncertainty over cell phones is small, and if there is a link, it is likely drowned out by larger effects and may be impossible to prove in long term studies.
Weight of Evidence Approach
The “weight of evidence” approach to evaluation of causality is often vilified by cell phone and WiFi scare mongers as being an inadequate way to judge the evidence – often because it disagrees with their own sentiments about the science. If you can’t disqualify the evidence, then you can go after the method of evaluation and disqualify that, right? Of course, the weight of evidence approach is often portrayed as a dumbshow of putting all the “positive” trials on one side of the scale and all of the “negative” trials on the other and taking the difference in mass as the evidence. This is how Dr. Phillips characterised it in his paper on electromagnetic fields and DNA damage, as well as his appearance on CBC Radio. Of course, the procedure is much more like a systematic review, where all of the papers, regardless of their outcomes, are weighed for their quality. (The higher quality studies will have good internal and external validity, proper blinding and randomisation, large enough sample size, proper controls and good statistical analysis; as well as being reproduced by independent investigators.) Then they are tallied and a rational conclusion is offered as to the most likely state of the evidence (of course, it is much more involved than I am stating, but suffice it to say, it does not involve a scale.) This is standard operating procedure and, in fact, is what we all do when we are evaluating evidence: we decide which studies are good and we pool the evidence before we make a decision.
Of course, the systematic review and the weight of evidence approaches decide what the good qualities are going to be prior to initiating the literature search. This reduces the amount of bias the investigator may bring to the table when making a decision. This is why the WHO, Health Canada, and many other governmental bodies who are responsible for setting policy use this system. The WHO defends this practice in their guidelines for assessing health information:
“All studies, with either positive or negative effects, need to be evaluated and judged on their own merit, and then all together in a weight-of-evidence approach. It is important to determine how much a set of evidence changes the probability that exposure causes an outcome. Generally, studies must be replicated or be in agreement with similar studies. The evidence for an effect is further strengthened if the results from different types of studies (epidemiology or laboratory) point to the same conclusion”
They are interested not in a specific outcome, but the one that is most true. The opposite is true for Havas, Davis and those groups spreading fear about cell phones and WiFi: they have made up their mind prior to evaluating the evidence, so they only give weight to those studies that agree with their premise and ignore those that do not. The evidence for WiFi dangers disappears when looked at closely, and the few positive findings from some labs are never reproduced independently. The probability that cell phones or WiFi are causing any health concern remains very, very low.
Let me be very clear here: no one is saying that we should ignore the problem. As is stated in the WHO description above, the symptoms that people are reporting are real, we just disagree on the source. People get headaches. They are restless, have foggy brains, have heart palpitations and get cancer. The evidence does not support the conclusion that cell phones or WiFi are the source, but we should continue to look for the source and make sure we are not missing other possible subtle environmental effects or allow anxiety disorders to go undiagnosed.
To be frank, I do not care if we are warned to limit our cell phone use and I don’t care if a telecom company is forced to move its cell tower off the top of a building or away from a park. I will not be the one advocating for the placement of a repeater station on the behalf of a private company. If a condo board does not want to allow this, it is within their right to deny access or get out of a contract. What is at stake here goes beyond how many bars are on my cell phone or my access to a wireless Internet source (although access to the internet is a social justice issue.) What is at risk is an entrenchment of the distrust of science and the emboldening of those mistaken individuals attempting to make the public afraid in light of very poor evidence. A very good point was brought up in CASS’s discussion about the hysteria around EHS: if people are convinced that the real symptoms their child is feeling at school are because of the wireless network, it may distract the parents and medical professionals from identifying a true, and possibly life threatening, condition. Heart palpitations are not normal. It is common for them to be caused by anxiety, but if there is a electrical problem in the heart and it goes undiagnosed because we blame it on the WiFi network, that could spell peril for the child involved. That is why skeptics speak out against the bad science around cell phone and WiFi. We, as a society cannot be blinded by ideology and must continue to search for the scientific truth around a phenomena in order to be prepared to deal with it properly.
On Monday: how a certain sector of the public is responding to the fear spread by the mis-informed and ideologically steadfast.
picture licensed under Creative Commons by Lmduga
*originally given as Canadian – corrected to Ontario – again, last minute edits are dangerous :)