Biological Effects - RF/Microwave Interaction with Biological Tissues - page 125

millimeter-wave exposure. The thermodynamic explanation published by
Chukova in 2001 takes into account luminescence, change of chemical bond
energy, and heat.

3.9 EPIDEMIOLOGY STUDIES

The widespread use of hand-held mobile phones has as a consequence that
many people routinely place RF/microwave transmitters against their heads.
This is a good reason to warrant examination of the safety of this form of
radiant energy. There should have been good reasons to be concerned about
exposure to television and FM radio transmitters earlier too, but this did
not happen. It is the use of mobile phones that has raised concern about
microwave exposure as well as, mainly in Europe, exposure to the relay sta-
tions of digital mobile telephony. This has led to epidemiology investigations
involving statistical analyses of health records and standardized tests on
animals. Both types of investigations have been led on cancer and genotoxicity,
while brain cancer dominates public discussion. On-going research is reviewed
at regular intervals [104, 105].
Up to now, studies do not establish clearly that RFs lead to cancer. To estab-
lish such effects, the difficult question is dosimetry , as explained in Section
3.1.2: Measuring the exposure to which a human being is submitted is one
thing; estimating what it has been in the past is much more difficult. Because
of this difficulty, added to the fact that low-level exposure is investigated, it
is very difficult to prove either one effect or the opposite. Identifying links
between cancer and environmental exposure of any kind is extremely difficult
because of the absence of a single cause of cancer and for a variety of other
reasons. Even if mobile phones had no connection to cancer, given the hun-
dreds of millions of mobile phone users around the world, thousands of users
would develop brain cancer every year.
Brain cancer takes years or decades to develop, and the studies say nothing
about future risks. Detecting small or long-term cancer risks through statisti-
cal analyses of health records is not an easy task. Detecting small increases in
risk would necessitate large studies that are difficult to control and may be
controversial in their interpretation. Any valid study would have to assess an
individual's use of mobile phones over a decade or more, an assessment com-
plicated by the rapid technological developments in this industry.
Animal studies are the other main source of information used in cancer risk
assessment. They are easier to control than epidemiology studies. They have,
however, uncertain relevance to human health. It should be remembered that
frequency scaling, defined in Section 3.1.2, enables use of results obtained with
a given object and to adapt them to predict the results to be obtained with
another object, similar in form to the first and differing only by a scale factor.
This can be strictly true only in loss-free situations, however, which is not the
case in living tissue.