What is the main source of man-made radiation ? What is its radiation level ?

More than 90% of man-made radiation received by human comes from medical diagnoses. The annual dose of man-made radiation received by people arising from medical diagnoses ranges from 0.04 mSv to 1.0 mSv. This is only a fraction when compared with the annual dose of natural background radiation received by people, which is in the range of 1 mSv to 10 mSv.