Why are gamma rays dangerous?

Alpha, beta and gamma radiation. The degree to which each different type of radiation is most dangerous to the body depends on whether the source is outside or inside the body. read more

Gamma rays are dangerous because they cause cellular damage that leads to DNA damage, cancer and radiation sickness. Because gamma rays are such a high-intensity, ionizing form of radiation, they pass through normal protections, such as skin, clothing, foil and goggles. read more

Gamma radiation results from radioactive atoms. When the ratio of neutrons to protons in the nucleus is not compatible, and the binding energy is not enough to keep the nucleus intact inside the atom, the atom becomes unstable. read more

Alpha and beta rays can create multiple ions, but a gamma ray (usually) can only create one. So, yes, gamma rays are the least dangerous when compared to alpha and beta of the same energy. The multiple ionizations will be close together so they have a greater chance of overwhelming the healing processes. read more