Microwaves have a similiar frequence of vibration of many molecules and by increasing these vibrations can result in heating. Microwaves can also heat body cells this way. Microwaves are used in mobiles and the increased use of mobiles have raised concern as they are often held so closely to the brain. There have been suggested links with brain tumours but nothing has been proved yet.
The infrared range of frequencies can make surface molecule of any substance vibrate and like microwaves, this too can have a heating effect.
If the human body is exposed to too much infrared, it can result in skin burns.
Ultraviolet has got more energy than and a higher frequency than infrared. It is ioninsing which means that it can knock electrons off atoms. Sunburns happen when the human surface skin cells have absorbed too much Ultraviolet radiation in the sunlight. This can cause cell destruction and cell mutation which can lead to skin cancer. UV in sunlught can also cause eye damage.
X rays and Gamma rays
X rays and gamma rays are very high frequency waves which lotsof energy and is ionising, which means that they can knock electrons off atoms. This means they can be much moore damaging and can penetrate further into the body Like all iosing radiation, they can cause cell mutation or cell destruction, leading to tissue damage or Cancer.