"Repeated Wi-Fi studies show that Wi-Fi causes oxidative stress, sperm/testicular damage, neuropsychiatric effects including EEG changes, apoptosis, cellular DNA damage, endocrine changes, and calcium overload." Full PDF available. Wi-Fi radiation, as with any other electromagnetic signal, follows an exponential decay with distance. This is why it's important to keep phones, laptops, and routers a safe distance from your body. Safe distance can be determined by output power of device. Output power is determined by country and device type, and each country has their own legal limit for exposure. But these limits may be under reported because of industry lobbying, as the new research above points out. There is no universal rule, but in general phones/routers should be kept at least 5-10cm away from vitals (eg avoid holding phone in pocket or undergarments), routers at least 1m. See also "Specific absorption rate" (SAR): [https://en.wikipedia.org/wiki/Specific_absorption_rate](https://en.wikipedia.org/wiki/Specific_absorption_rate) US: 1.6W/kg per 1.6g tissue EU: 2 W/kg per 10g tissue