Which type of radiation is known to be the most harmful to the human body?

Gamma radiation is considered the most harmful type of radiation to the human body due to its high energy and deep penetration capabilities. Gamma rays can penetrate most materials, including human tissue, which allows them to travel through the body and potentially cause damage to internal organs, tissues, and DNA. This deep penetrating nature means that gamma radiation can affect cells even if they are not directly in the path of the source, increasing the risk of radiation-induced illnesses, including cancer.

In contrast, alpha particles have a relatively low penetration ability and can be stopped by a sheet of paper or the outer layer of human skin, making them less hazardous when outside the body. Beta particles can penetrate deeper than alpha particles but are still easily stopped by materials like plastic or a few millimeters of aluminum. X-rays, while also penetrating, typically have lower energy levels than gamma rays and are used in controlled environments for medical imaging rather than as a significant radiation hazard.

Therefore, gamma radiation's high energy and ability to penetrate human tissue make it the most dangerous type of radiation when considering overall health risks.