The danger from an electromagnetic wave increases as its frequency increases. Too much exposure to some parts of the spectrum can harm the body.
- Microwaves cause internal heating of body cells.
- Infrared causes skin burns.
- Ultraviolet damages surface cells and the eyes. Over time this can lead to skin cancer and eye conditions.
- X-rays and gamma rays can cause mutation or damage to cells in the body. A mutation can lead to cancer.
The harm depends on the amount of exposure. A short time in weak radiation is much less risky than a long time in strong radiation.