Radiation is all around us and too much of radiation is a bad thing so… are we all just screwed from all the radio waves and microwaves and ultraviolet radiation and rainbows and x-rays and radon and nuclear radiation in the world? Not exactly. Ted-Ed explains in the video animation below how not all radiation is created equal (we just have to protect ourselves from the ionizing radiation) and details how much radiation is actually damaging for us (four Sieverts!).
source: gizmodo.com by Casey Chan