Since the introduction of mobile phones, concerns have been raised about the potential health impacts from regular use.
As mobile phone penetrations grew past fixed landline penetration levels in 1998 in Finland and from 1999 in Sweden, Denmark and Norway, the Scandinavian health authorities have run continuous long term studies of effects of mobile phone radiation effects to humans, and in particular children. Numerous studies have reported and most studies consistently report no significant relationship between mobile phone use and health. Studies from the Institute of Cancer Research, National Cancer Institute and researchers at the Danish Institute of Cancer Epidemiology in Copenhagen for example showed no link between mobile phone use and cancer.
The Danish study only covered analog mobile phone usage up through 1995, and subjects who started mobile phone usage after 1995 were counted as non-users in the study.
The health concerns have grown as mobile phone penetration rates throughout Europe reached 80%–90% levels earlier in this decade and prolonged exposure studies have been carried out in almost all European countries again most reporting no effect, and the most alarming studies only reporting a possible effect. However, a study by the International Agency for Research on Cancer
of 4,500 users found a borderline statistically significant link between tumor frequency on the same side of the head as the cell phone was used on and cell phone usage.
One study that reviewed the link between cellphones and **** quality found that heavy mobile phone users (>4 hours per day) had significantly less viable ****(WHO
morphology score was less than half of the lower time cell phone users).
A prospective study of 13 normal men found that significantly increasing their cell phone use (>6 hours each day for 5 days) caused a marked short-term reduction of **** quality. 
This is considered to be a thermal effect, since the testes are vulnerable to heating by RF energy because of poor circulation and heat is known to have adverse effects on male fertility.
The eyes are the other part of the body known to be poor at dissipating heat. Experiments have shown that short duration exposure to very high levels of RF radiation can cause cataracts in rabbits. 
The non-thermal effects of RF radiation are an area of active study. from wikipedia