Radar, microwave communications, short-wave communications, radio waves, has been used for hundreds of years; television waves, cell phone communications, and so on a variety of electromagnetic waves, medical inspection equipment, and so on, also used for decades. Synthesize the world's various aspects of the news and research, electromagnetic radiation on the human body is indeed a certain impact, but has not been found to be harmful.
Relatively speaking, the use of radar on the airplane is short-lived, far less than the impact of cell phones and computers on people.