It's not about background radiation level. It's about the risk of ingesting or inhaling a speck of radioactive material. If this particle settles somewhere in your body, it means that the cells in the immediate vicinity of this particle are going to subjected to very intense radiation.
Then Mozilla Thunderbird, then TortoiseGit, then TortoitseSVN, then Sublime Text Editor, then Notepad++, then Notepad++ informs me there is an update of a plugin that I never use, then VLC media player, then Google Chrome, then Oracle VirtualBox, then Visual Studio proudly announces a service pack, then Windows informs me that it wants to reboot in 10 minutes.