I think it is a biomedical fact that environmental electromagnetic fields (EMFs) such as those from powerlines and cell telephones are health hazards, but all the industry experts I’ve ever known disagree with me, at least publicly. Their opinions are less rational and less respectful of biomedical science than mine. Nevertheless because they have always spoken from the bully pulpit, they succeeded in making indiscriminate denial of responsibility for inadvertently causing EMF hazards seem as natural as the law of gravity.
I understand why industry experts are generally more persuasive than I among laymen and officials of government agencies who don’t have the time or inclination to give the EMF issue more than a passing glance. Companies have the rights to advertise, engage in creative exaggeration, and even tell outright lies. Political decisions by executive agencies normally favor societal stability over individual health. People are busy.
The volume and repetition of the misleading industry message about EMF safety, and its generally favorable reception in the corridors of political power are two good reasons ordinary people tend to disregard consideration of the causative role of EMFs in their diseases. But I think a more crucial reason is the pervasively popular misconception of what biomedical science is and how it works.
Laymen commonly assume that grammatically opposite statements such as EMFs are health hazards and EMFs are not health hazards are mutually exclusive in the sense that the truth of one excludes the truth of the others. Actually, however, grammatically opposite biomedical facts are a necessary consequence of the canonical method of biomedical science. This popular misconception of biomedical science is the soil in which the seeds of doubt and confusion about EMF hazards planted by industry and watered by government are able to take root and grow.
My aim here is to explain why both statements are simultaneously true. My goal is to lessen the importance of the misconception in accounting for the unhappy situation in which people blunder into making themselves sick. I will not address the problem of which fact is truer, but rather will focus on why EMFs are health hazards and EMFs are not health hazards are both plausible biomedical facts.
Necessity for an Empirical Approach
To explain how grammatically opposite statements can both be biomedical facts an inquiry is needed into what biomedical facts are and how they are made. They do not come from holy books but rather are the product of a broadly used but poorly explicated method-based enterprise called biomedical research.
The textbook definitions and philosophical explanations of biomedical research that I know about are fatally inadequate. The definitions are grossly simplistic (the stuff you get when you Google “scientific method”), or solipsistically irrelevant (the opinions of Popper, Kuhn, Hempel, and Kitcher). These attempts were failures because they didn’t even come close to describing what I and my colleagues who also are professional biomedical research scientists really do, day in and day out. What the community of biomedical scientists does is the sole valid standard for identifying what biomedical research is. (I am not addressing what it was, or what any particular philosopher thinks it ought to be, but rather what it is in modern times.)
An understanding of what biomedical scientists do can be gleaned from an analysis of biomedical research described in scientific journals. I randomly chose Issue 5248 of the prestigious journal Science, published January 26, 1996, but any issue of any journal would suffice because the insights gained don’t change.
The biomedical facts contained in the 16 reports in the Issue fell into two broad classes, inferential and observational (Table). Grammatically opposite biomedical facts regarding observations are essentially nonexistent because measurement methods and observational techniques are generally well-established and agreed upon among experts. For example, I have never seen a serious disagreement among scientists regarding the validity of observations of the intensity, frequency, or dynamical properties of environmental EMFs. Disagreements regarding biomedical measurements sometimes occur but, for our purposes, they are inconsequential. I will therefore focus on the cognitive biomedical facts in the reports in order to identify the nature of inferential biomedical facts (Figure).
Inferential Biomedical Facts
The report dealing with why normal cells usually do not grow when they become attached to a substrate (10) was a typical example of how a biomedical fact was determined. The authors presented measurements of the concentration of CDK inhibitors and the amount of phosphorylation that occurred in a particular type of cell when the cells were attached to glass, and compared those values with similar measurements in unattached cells of the same type. Given what was generally known about how cells stick to glass, the authors concluded that the observed changes in concentration and phosphorylation were a reasonable explanation for why cell-sticking occurred.
I personally don’t accept the author’s reasoning because the molecular biology of cell adhesion involves numerous other mechanistic processes, changes in any of which are equally reasonable explanations for the observations. So, the authors (and the editor of Science) have their opinion, and I have mine. In other words, the statements “CDK concentration changes make cells stick” and “The evidence does not indicate that CDK concentration changes make cells stick” are both biomedical facts (which statement is more true in the sense of more justified is not the kind of issue I’m addressing here). A similar analysis can be carried out for every other report in the issue.
The term most frequently employed in the reports to describe the link between the study measurements and the putative inferential biomedical fact was “suggests”, but many other euphemisms were used in the other reports involving inferential biomedical facts (Table) including: “indicate”; “may have been instrumental”; “not unreasonable”; “results in”; “may be one of the mechanisms”; “consistent with”; “provide direct evidence for”; “is the most likely”; “is involved in”; “raised the possibility”; “believed that”; “may underlie”; “provide insight into”; “support a determining role”; “orchestrated”; “does not readily account for”; “showed”; “confirmed the role of”. The English language is rich in expressions that invite the reader to believe what the writer believes. The critical point is that none of the asserted biomedical facts requires acceptance because there are always variables other than those evaluated by the authors that could have been responsible for their observations. In other words, whatever biomedical claim one regards as a fact, the judgment of biomedical factness is always partly subjective, just as is the case for other kinds of human judgments.
Second Dimension of Subjectivity
A distinctly different subjective dimension regarding inferential biomedical facts arises whenever a similar or related study is performed by other investigators. Consider the biomedical fact urged by the authors that changes in CDK concentration and phosphorylation caused loss of cell anchorage (10). Assume that another group performed a similar study but did not find the same results. Although replicability is the hallmark of scientific validity, a failure to find something is not good evidence that the thing sought doesn’t exist because anybody can find nothing. Consequently a negative report cannot automatically be interpreted as undercutting the reliability of a positive report. In actual scientific practice, the attitude adopted toward a mixed state of evidence depends on the interests of the person or group doing the evaluation. An author of a review article would typically hedge a decision (“The data is conflicting, and no firm conclusion is possible”). But sometimes hedging is not a viable option, as when one conclusion or the other would materially influence the design of particular experiments. In these cases, various factors are normally considered including the extent of the evaluator’s faith in the ability and honesty of the investigators, the reputation of the laboratories, whether they were in industry or academia, the track record of the investigators, insider information, and style of presentation of the results. Some evaluators will consider the relative prestige of the investigators’ institutions or their nationalities. The number of factors that may be considered is indeterminately large. The point is that, in the face of mixed results, which is commonly the case, the cognitive value of the scientific evidence in a particular area depends on who is evaluating it, and why. There is no necessarily right or wrong means of performing these analyses.
Third Dimension of Subjectivity
A still further dimension of subjectivity regarding what constitutes a biomedical fact involves the process by which it is given meaning in the world outside the laboratory. Consider the conclusion that vigilance caused an increase in brain blood flow (12). Assume that exactly the same change in blood flow occurred when subjects were exposed to EMFs. To avoid the difficulty of mixed results from different studies discussed above, assume further that the study was exactly replicated many times, and always with the same result. Would the totality of that evidence indicate the existence of a health hazard to individuals exposed to environmental EMFs? Because a change in blood flow accompanies every cognitive act and every sensation, it could be argued that changes in brain blood flow caused by EMFs were normal physiological responses, and thus not hazardous. On the other hand, a change in blood flow also accompanies every pathological change, and perhaps the adopted decisional rule should be to err on the side of caution and tentatively regard the exposure as a hazard, at least in the case where the exposure is involuntary. Either way, it is clear that the validity of the putative biomedical fact will be made, not found.
Biomedical Facts Like Jury Decisions
The reports in Issue 5248 clearly revealed that there are multiple dimensions of uncertainty associated with biomedical facts. The reports showed that inferential biomedical facts generated by experts while following the canonical method of biomedical research are inherently problematical in the sense that reasonable scientists may differ profoundly regarding the degree of validity of the facts.
It is indubitably the case that the formation of biological generalizations by extrapolation of cell, animal, and human data to form judgments regarding health risks fundamentally involves non-empirical elements. That’s not to say that biomedical facts like those relating to EMF safety are entirely subjective, only that they contain subjective elements, like the decision of a jury. The jury metaphor works well at two levels. It illuminates the inherently mixed subjective–objective nature of human judgment regarding any factual claim. The metaphor also highlights the notion that a judgment entails a numerical justification scale, like preponderance of the evidence for civil trials (>50%), clear and compelling in first-amendment cases (>75%), and beyond a reasonable doubt in criminal cases (>95%).
Conflicts resulting from differing subjective elements are particularly acute in epidemiological studies. In these studies, hugely and explicitly non-empirical decisional principles such as Koch’s postulates and Hill’s criteria are commonly used to rationalize idiosyncratic denials of EMF hazards.
The subjective elements are non-empirical reasoning principles and therefore cannot be determined by the data, but only on the basis of policy or purpose. Biomedical data never speaks for itself but rather is always spoken for, so its ultimate meaning is always in the eye of the beholder.
People can differ regarding what conclusions are well justified, so naturally they can differ regarding what biomedical facts the data suggests. Considering the fundamentally divergent interests of the EMF industry, the involuntarily exposed laymen who have a serious interest in minimizing their environmentally-triggered illnesses, and the government, it is not surprising that these three stakeholder groups do not see eye to eye to eye. EMF industry leaders don’t want to cause your cancer, but their interest in you not getting cancer is less than yours.
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