This is extremely controversial but we can’t ignore that plenty of animal models indicate that exposure to electromagnetic radiation increases the risk of tumor development. While human studies are rare, reports and case studies abound. One such case involves a young 21-year-old woman who developed breast cancer. What makes this case unique was that her family did not have a predisposition to breast cancer… and she developed the tumor right on the spot she carried her cell phone in her bra. 
Katie Wells, CTNC, MCHC, Founder and CEO of Wellness Mama, has a background in research, journalism, and nutrition. As a mom of six, she turned to research and took health into her own hands to find answers to her health problems. WellnessMama.com is the culmination of her thousands of hours of research and all posts are medically reviewed and verified by the Wellness Mama research team. Katie is also the author of the bestselling books The Wellness Mama Cookbook and The Wellness Mama 5-Step Lifestyle Detox.
The aim of this study was to investigate electromagnetic radiation (EMR) transmitted by wireless devices (2.45 GHz, 3h/day for 30 days), which may cause physiopathological or ultrastructural changes, in the testes of rats and address if the supplemental gallic acid (GA) may reduce these adverse effects. EMR only group was shown to have higher oxidative stress, decreased testosterone and VEGF levels, increased prostaglandin E2 and CGRP, as well as decreased numbers of spermatozoa. Long term EMR exposure resulted in testicular physiopathology via oxidative damage and inflammation. GA may have ameliorative effects on the prepubertal rat testes physiopathology.
The use of Wi-fi has increased rapidly in recent years. Through the use of this technology, electronic devices are connected to a computer network wirelessly using radio waves, or radiofrequency (RF) electromagnetic energy (EME), thereby eliminating or reducing the need for network cables. A common example is a laptop connected to the internet using a wi-fi modem at home. Wi-fi access points can also be found in schools and many public areas. People in a wi-fi enabled environment will be exposed to low level RF EME from time to time when using the network on computers and also from the access points. There is some public concern about potential health effects associated with RF EME emissions from wi-fi in homes, schools and other places.
4. For the reasons mentioned in #3 above, an at-home meter test is extremely inaccurate and unreliable. That said, a far field RF meter such as the one you are using is highly influenced by ambient RF levels that exist almost everywhere. Again, we do not aim to eliminate the radiation from the device, nor from your surroundings, but our technology does deflect the radiation away from the body.
Ok, update: Crownstarqi very kindly sent me 2 cell phone shield stickers, but I originally ordered the 6 pack of much thinner rectangular stickers that I could stick more places. I'm too electromagnetically intolerant to even own a cell phone, so I don't know what to do with these! I don't dare bother them about this, b/c they sent me the shield things all the way from China, but I was really hoping to just put more of the rectangular 6-pack stickers on my laptop, to see if more made a difference. It was a very nice gesture on their part, but I'm now concerned that they thought my initial review was of the shield-shaped stickers, when it was a review for these rectangular ones. I noticed that someone else thought they were ordering the 6-pack, and ended up getting a single shield-shaped sticker, instead. This is very confusing & I'm going to just...count my blessings & get on w/ my life. I don't trust any stickers that make the "negative ion" claim, b/c they're often radioactive. I don't realy know what to say, or what review to give, at this point, but I think Cronstarqi are very kind to have sent me something for the trouble w/ my original order, even though what they sent as a replacement was NOT what I had originally ordered. Maybe this was deliberate? I don't know. The package on the shield-shaped stickers says, "The product can only be used as health care instead of replacing the professional medical treatment." I'm so confused, but thanks anyway, to the seller, and the shield-shaped stickers are very pretty. I'd review them, but I have no cell phone & no verified purchase to back up my review. -Account holder's progeny.
The energy of electromagnetic radiation is determined by its frequency; ionizing radiation is high frequency, and therefore high energy, whereas non-ionizing radiation is low frequency, and therefore low energy. The NCI fact sheet Electromagnetic Fields and Cancer lists sources of radiofrequency radiation. More information about ionizing radiation can be found on the Radiation page.
The Federal Communications Commission (FCC),  US Government Accountability Office (GAO),  and the US Food and Drug Administration (FDA),  have all concluded that there is no evidence in the scientific literature proving that cell phones cause brain tumors or other health problems. According to the FDA, "attempts to replicate and confirm the few studies that did show a connection [between cell phone radiation and head tumors] have failed." 
The potential health impact of Wi-Fi, even at low exposure levels, can no longer be called into question or relativized away, not even by those studies that found no effects. The decision-makers in government, school boards, and health agencies have a responsibility to deal with the available body of research and not to be deceived by the arguments of the industry lobby or boilerplates of government institutions. Health risks are a reality. It would be particularly important to carry out further research regarding the effects on the brain and young people. The application of the precautionary principle, which is recognized in all European countries, only allows for one conclusion: Wi-Fi must not be used continuously and close to the human body. I is no coincidence that the user guide of the Telekom Wi-Fi router states: “The integrated antennas of your Speedport transmit and receive wireless signals, for example, to provide Wi-Fi connectivity. Avoid placing your Speedport in close proximity to bedrooms, children’s rooms, as well as common rooms and lounges to keep the exposure to electromagnetic field as low as possible.” In their joint appeal with regard to Wi-Fi, the Cyprus and Austrian medical associations call on decision-makers to "promote age-related rational application of digital technology and not allow at schools, particular at preschool, kindergarten and elementary schools wireless networks and opt for wired connections" (ibid). Lawmakers are called upon to adjust protective legislation to the current state of research and to support research into alternatives to Wi-Fi such as VLC technologies (visible light communication, Li-Fi).
Joel Moskowitz (@berkeleyprc) of the University of California, Berkeley School of Public Health, US, says: “This is the largest technological experiment in the history of our species, with potential health risks we still know next to nothing about.” This view is shared by Denis Henshaw, professor of human radiation effects at Bristol University, UK, who said: “Vast numbers of people are using cell phones and this could be a time bomb of health problems.”