Topic 3 - Dangers of EM Waves Flashcards
how are some EM radiations harmless?
they pass through soft tissue without being absorbed
how are other types of EM radiation harmful?
they can be absorbed and cause heating of the cells, or cause cancerous changes
how do the effects of EM radiation depend on frequency?
the higher the frequency of EM radiation, the more energy it has, so the more harmful it can be
how are microwaves dangerous?
they have a similar frequency to the vibration of many molecules, so they can increase these vibrations. this results in internal heating.
how are IR waves dangerous?
they can make surface molecules vibrate, which has a heating effect. this can cause skin burns.
how are UV waves dangerous?
some frequencies are ionising, so they can knock electrons off atoms. this can cause cell mutation/destruction.
how are gamma rays dangerous?
they are ionising, but carry more energy so they can penetrate further into the body, so cause more damage
how do you protect yourself from microwaves?
shielding to prevent microwaves from reaching the user
how do you protect yourself from IR radiation?
use insulating materials to prevent IR from reaching your skin
how do you protect yourself from UV rays?
wear sunscreen with UV filters
how do you protect yourself from gamma rays?
sources of gamma rays should be kept in lead-lined boxes when not in use and expose should be limited.
