Mobile Phones and Fertility – what is the story?
This is in fact a tale of two stories, because we have one, which is weakly positive, suggesting some effect from the electromagnetic waves from mobile devices, and another, which is weakly negative, because despite a large sample size and a well-conducted study involving many men – in fact, 107,000 entrants – in a well-ordered study in a country with a relatively small population, we have not had a strongly positive conclusion that electromagnetic waves do affect male fertility.
This was a very large retrospective study and it involved all young males who were potential Army recruits.
What started the interest in electromagnetic waves were animal studies in mice and laboratory studies on ejaculated human sperm. These latter studies were of course in vitro, or in a test tube, and neither the mice nor the specimens collected from men really mimic normal sperm production in the testicles, even when there is a mobile phone in the trouser pocket.
One might have thought that a study that ran from 2005 to 2018 and that involved all those potential military recruits aged 18 to 22 would be bound to have some kind of absolute result. This is especially so as in fact, in Switzerland, looking at all military recruits of the ages 18 to 22 was covering 97% of the male population. So although we started with 107,000 men, the uptake was only 5.3%, and in terms of completing the study with all the pre- and post-study period documentation, there were in fact only 2886 men eligible for study. This represents 3.1% of the 97% of the male population who started out on the track.
Even so, with 2886 men studied over a long period of time, one would expect to have a clear outcome. In fact, of course, there may have been many other factors, known as confounders, but as men who use their phone 20 times a day or more were of particular interest, it was clear that these men did have a lower sperm concentration, but of course this is only an association, rather than indicating causation.
Thus, with only one positive finding, that use of the mobile phone more than 20 times daily did alter concentration, we really cannot make a conclusion. We have to bear in mind that even large retrospective studies usually fail to prove either a positive or a negative, and this is why evidence in the field of fertility is so difficult to come by.
So really, the weak conclusion is that there may be some effect of electromagnetic waves, but equally we must conclude that it is extremely difficult to prove either a positive or negative causation, even when a retrospective study is designed so carefully, involves so many potential recruits and runs for such a long time.
My own view does take note of the weak association between phone use of more than 20 times daily and a lower concentration on semen analysis.
Interestingly, there seemed to be no similar correlation between whether the phone was kept in a trouser pocket or elsewhere on the body.
Therefore, I think we should be mindful of this association, but I do not think this is sufficient to carry the phone around in a briefcase.