i do not believe that these tiny magnets used to hold down your shirt collar will have any bodily effects whatsoever. it will not cause tremors or cause any issues with the iron in your blood stream.
is it dangerous to have these (<link> magnets in my collar all day? . hey there . just wondering if there are any long term effects to having thesemagnetic collar stays hovering around my collar bones all day. am i going to get weird tumours or something? will it mess with the iron in my blood? . thanks