Thormod Henriksen, Biophysics and Medical Physics Group, Dept. of Physics, University of Oslo: This is an update (2016) on radon and lung cancer. It is also a discussion on the rise and fall of the famous LNT (linear no threshold) theory. The theory has caused much anxiety and prevented a reasonable use of nuclear power, which is essential for long term prosperity of the human race, preservation of wildlife habitat, biodiversity and healthy environment. This outstanding research and teaching group at the University of Oslo presents this in a way that is interesting for the public worldwide.