Biomedical Engineering Reference
In-Depth Information
However, there are many laboratory experiments (I have
heard that there are up to one hundred) that purport to have
demonstrated effects of very weak fields on cells in vitro. All
have been accepted without a rational, accepted model for
biological interactions of EMF. Are they all wrong? If so, why?
The probable answer is that experimental errors have been
accepted as real effects. Error explains the incoherence and lack
of division of the positive reports. It also explains the almost
universal lack of a dose-response relation. After more than 20
years of such studies, no well-defined, replicated demonstration
of the effects of very weak fields has emerged. Error is the best
explanation for all observed reports. (Two workers described in
the early 1990s a threefold increase in Myc oncogene expressed
RNA on exposure to a low-frequency electromagnetic field, which
was then implicated in carcinogenesis. The results could not be
replicated by two other groups, which had tightened controls
and certain calibrations. The repeat work was reported in the
Journal of Radiation Research, October 1995, and reviewed in
Science, September 1995. The original erroneous report was
widely disseminated in the press and reawakened interest in an
EMF/cancer causal relationship.)
But if there is so much smoke, is there not fire? Too much
smoke with no sight of flame, suggests to experienced scientists
that the smoke is only fog. Seven years ago, I served as chairman
of a committee that met in Salt Lake City to report on the National
Cold Fusion Institute. At that time, there were 100 papers, from
10 different countries, reporting results that were interpreted as
evidence of cold fusion. But cold fusion has been tossed into the
dustbin of discredited science; there is no cold fusion.
Flawed Studies
Epidemiological studies that claim to demonstrate effects of weak
electromagnetic fields have had great public impact because the
techniques and results can be stated in (deceptively) simple ways.
In fact, much of the work reporting positive effects is critically
marred by errors in technique or analysis and none is even nearly
definitive.
As an example of the deficits of a relatively good study, I
consider the heralded Swedish measurements of Ahlbom and
Feychting that have been cited as showing that the magnetic
fields from power distribution systems in Sweden considerably
