Avoided by anyone who has any metallic object

Use of a mobile phone should be avoided by anyone who has any metallic object in or on their head, whether magnetic or not, such as amalgam fillings and dental bridges, metal plates, screws, clips, body ornaments, earrings or metal framed glasses. The same is true for those with walking frames, wheelchairs or metal crutches, so as to avoid increasing radiation by the phenomena of reflection, amplification, resonance, passive reemission, etc.