The short-wave UV-C radiation is almost completely absorbed or reflected by the earth's ozone layer, so almost nothing arrives on the earth. A good thing is because the high-energy, short-wave UV-C radiation is harmful. It can penetrate the tissue layers of the skin (and the eye) and lead to changes in the cells there. In the worst case, the genetic information (the genes) is affected, so that the cells can either no longer divide - or they begin to divide in an uncontrolled manner (this is then called a malignant tumor, i.e., cancer). It is all the more important that we humans...