*The ability to browse the internet (for tweens and teens that have access to the internet on their cell phone) opens up an entirely new area of safety concerns. Not only can kids search the web more discreetly, most parents do not view this activity as of much of a risk as they do allowing their kids to search on a regular computer. The fact is, the dangers are just as real and even worse when you consider that with a smart phone, kids can search the internet outside of the watchful eye of parents while using their cell phone in school.
As our video points out: Measurements will vary with signal strength and other factors and that includes ambient energy. I talk about ambient energy in a lot of my videos-it's the energy that's in whatever environment I happen to be measuring in that's coming from a source of wireless energy that isn't the subject of what I'm measuring. My home is not a lab of course, but fortunately it's always measured very low for RF radiation.
Exposure to non-thermal radio frequency radiation from Wi-Fi and cellular phones can disrupt normal cellular development, especially fetal development. A 2004 animal study linked exposure to delayed kidney development.  These findings were supported by a 2009 Austrian study. In fact, the disruption of protein synthesis is so severe that authors specifically noted, “this cell property is especially pronounced in growing tissues, that is, in children and youth. Consequently, these population groups would be more susceptible than average to the described effects.”  In short, bathing the developmentally young in Wi-Fi increases their risk of developmental issues.
Radiation from cell phones can damage sperm. Cell phone storage in front pockets has been linked to poor fertility and higher chances of miscarriage and childhood cancer.  According to the Cleveland Clinic Center for Reproductive Medicine, semen quality "tended to decline as daily cell phone use increased."  According to a May-June 2012 meta-study in the Journal of Andrology, "men using mobile phones have decreased sperm concentration" in addition to "decreased viability" of their sperm. 
It can be inferred from the aforementioned works that increase in scrotal temperature can result in reduction of sperm motility, which consequently enhances the probability of infertility, lessens sperm production, decreases sperm concentration by 56% [Hjollund et al., 2002], increases ROS, and negatively affects sperm morphology, increasing the number of sperm with physical dimensions different from those of normal sperm.
WiFi radiation exposures drop off significantly with distance (called the inverse square law). Many routers have a strong enough signal to maintain a connection up to 100m from the router. Make sure you put as much distance between you and your wireless router as you can without diminishing the efficiency of your connection. Remember: walls don’t stop wireless radiation, never situate a wireless router behind a bedroom wall.
Wi-Fi transmissions consist of sequences of RF burst signals or pulses ranging in duration depending on the amount of data being carried by a pulse(15). The proportion of time that Wi-Fi transmits RF signals is called the duty cycle. Joseph et al.(14) in measuring Wi-Fi in 176 different urban locations (outdoors, homes, offices) found a median duty cycle of 1.4% over all the measurements. Particularly in schools, Khalid et al.(10) in measuring Wi-Fi in six schools found a mean duty cycle from the access points of 4.8%. In our study duty cycle was measured separately for the 2.45 and 5 GHz transmissions when performing the stationary Wi-Fi measurements in the centre of the classroom. The median duty cycle for 23 schools that were measured in the current study was 6.3 and 2.4% for 2.45 and 5 GHz transmissions, respectively.
The legislators themselves say that no link has been demonstrated (Le Monde reports them as having been unable to identify ‘a causal link between the biological effects described on cellular models, animals or humans and possible health effects that result.’) and there is only limited evidence (one study, unconfirmed by any others) to suggest risk even for intensive users of mobile phones.
29. Carry your phone properly when you must carry it close to you. “If you must carry your cellphone on you, keep the keypad position toward your body and the back toward the outside to have the electromagnetic fields move away from you, rather than through you, according to Consumerist.” – Lizette Borreli, Teenage Girl Wakes to Samsung Galaxy S4 Catching Fire Under Pillow: 4 Ways to Make Your Cell Phone Safer, Medical Daily; Twitter: @lizcelineb
Since children’s skulls are thinner than adults’ and their nervous systems are still developing, researchers believe they may be at a greater risk for cell phone-related cancers. They’ll also be exposed to the potentially harmful radiation significantly longer than their parents’ generation. Until more is known about the possible carcinogenic effects of cell phone use, curb your kids’ cell phone habits by encouraging texting or using a landline instead—if they can actually recognize a landline anymore, that is.
Studies by five independent research groups regarding cell phones and brain tumors have revealed significantly increased risks of a benign tumour of the cranial nerve supplying the ear. This grows slowly and must be removed in a major operation that can result in permanent facial paralysis. Other risks found were cancer of the glial cells (including neurons) of the nervous system and cancer of the meninges, the membrane covering the brain and spinal cord.