Several studies or press articles suggest that keeping a cell phone in a male's trousers pocket (and cell phone usage in general) may harm that men's fertility (increase sperm issues):
- http://www.rense.com/general54/cellphoneusecanreduce.htm
- http://www.aaem.pl/pdf/14169.pdf
- http://www.fertstert.org/article/S0015-0282(07)00049-0/fulltext
- http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1807-59322009000600011&lng=en&nrm=iso&tlng=en
I think most of these sources are pretty old, and kind of vague about the exact protocol (i.e. was the phone in a call or waiting for one?).
Some other sources suggest that more studies are needed or that the risk is not obvious:
- http://www.rbmojournal.com/article/S1472-6483(15)00300-4/fulltext
- http://www.bbc.com/news/health-27767981
Is there a real risk?
Side question: I thought that a non moving cell phone waiting for a call was almost passive, that is, not emmiting continuously but mostly "listening the signal". Is a phone still harmful in this context?