This video will show you that Electromagnetic Radiation is emitted from WiFi wireless routers.
The amount of radiation is dependable of the amount of data being transmitted. If, for example, one person used this router to download and read text email via his laptop than the radiation's level will be modest, but if the same person will use the router to access the net and download a HD movie or to watch it real time (streaming) the level will be higher, much higher and for a longer time. You will not find a warning on the router or on the router's box. I my self has this kind of router, but the WIFI is always OFF, some routers can be configured no to transmit but not all.