Do cell phones in pants pockets really affect men's fertility?
A new study says yes — but it is riddled with errors
By Alexander Lerchi, The
Conversation | June 19, 2014
Relax. (Thinkstock)
A new study has claimed that keeping
mobile phones in trouser pockets can damage a man's sperm count, affecting his
chances of becoming a father. While the possibility that mobile phone radiation
could adversely affect fertility is understandably of great interest to the
public, there is no new information to be found here.
The question about whether non-ionising
radiofrequency electromagnetic fields (RF-EMF) that come from mobile phones are
harmful or not is as old as the technology itself. Decades of research in this
highly controversial area have led to two conclusions. First, that the thermal
effects from this type of "radiation" — often confused with the
ionizing radiation you get in X-rays — below the exposure limits adopted by
almost all countries, are around 0.1°C and therefore far too low to cause any
adverse biological effect. Second, that no so-called non-thermal biophysical
mechanisms, for example the production of oxygen-derived radicals, have been
identified. Because of this, the World Health Organization recommended no
further research initiatives in this direction in 2010.
The new research, published in
Environment International, is based on a meta-analysis of 10 (or
nine, this is somewhat unclear since in the text nine are mentioned, but the
tables and figures show 10) previous studies. But it repeats the mistakes that
are typical for this kind of review — the quality of the review depends on the
quality and criteria of the studies chosen. It appears to me that the studies
analyzed in this meta-analysis represent a patchwork of greatly diverse
methods, quality criteria, and biological outcomes which were squeezed into
something which looks like an overall analysis, but is in fact a mishmash. The
authors themselves admit that the studies they have chosen are very
heterogeneous; this only serves to limit the overall conclusion drastically.
For example, there are Forest plots —
a way of graphically presenting figures in meta-analyses — of studies based on
research conducted on cells in the lab (in vitro) and others based on people
(in vivo). Putting these two kinds of studies together simply doesn't make any
sense. They are entirely different, both in type of study but also in the
dosimetry — the calculation made to show how much of a radiation dose the body
or the cells have received and which is only available for the in vitro
studies.
The selection criteria for the
selected studies also appear to be somewhat arbitrary and lack the criterion of
whether they were done in a blind design fashion (that is, the persons doing
the experiment or the analysis were not aware of whether the cells/humans were
exposed or not in order to prevent a biased view on the results). Most studies
included in the meta-analysis do not fulfil this important quality standard and
thus may not be entirely unbiased, to say the least. It is also worrying that
the authors cite a study which
allegedly demonstrated that DNA in rat and human cells were damaged by exposure
to electromagnetic radiation from mobile phones. But evidence suggests this
study was based on fabricated data and I have argued elsewhere that
it should be retracted.
The speculation about mobile phones
carried in trouser pockets near the reproductive organs could hamper
"spermatogenesis and sperm production" is telling. On the one hand,
readers will of course agree that something emitting "radiation" must
not be carried near the testes or the ovaries. But mobile phones do not emit
anything while not in use (standby), except for a brief signal every hour or so
to signal the base station its status. In other words: carrying a mobile phone
does not mean constant exposure.
All in all, this study doesn't provide
any new information that should lead to panic. The result certainly doesn't
justify "further studies … to determine the full clinical implications for
both sub-fertile men and the general population" as the authors suggest.
At best, this study highlights the need for educating scientists on how to do
proper meta-analyses.
As I rode the train the other day, a toothy toddler wiggled and giggled in her stroller across from me, making faces at the people around her. The train was otherwise silent except for the steady announcements of stops over the loudspeaker. The train was packed and yet no one looked up from their phones to see the little girl make faces—not even her mother, who sat expressionless, silently swiping at her touchscreen. 
