5 GHz and 2.4 GHz WiFi routers are dangerous because they both interfere with your body’s EMF’s and cause things like headaches, tinnitus, sleep problems, crib death, male infertility, cancer and DNA damage (especially in infants and fetuses). There are literally hundreds of peer reviewed scientific studies by scientists from all around the world showing these health problems.
5 GHz is more dangerous than the 2.4 GHz units because it is twice the frequency and which makes it more intense. Kevin Mottus of the US Brain Tumor Association says that within the RF Radiation part of the electromagnetic spectrum, the higher the frequency, the more dangerous it is to living organisms. Also, because the 5 GHz frequency dissipates faster with distance, 5 GHz routers also emit the 2.4 GHz frequency. So you are being exposed to two frequencies of RF Radiation rather than just one.