The biological effects of radiation depend on a number of things: dosage, exposure rate, the type of radiation used and where the radiation is aimed in your body. Possibilities include radiation burns locally and generalized radiation sickness. Types of radiation include high-energy radiation such as X-rays and gamma rays, and particle radiation such as alpha particles, beta particles and neutrons. Alpha particles only affect the skin surface; beta particles can go below the skin; neutrons can go deeper yet. The short wavelengths of gamma rays and X-rays (electromagnetic radiation using photons) allow extreme penetration, sometimes completely through the body.
Cell Death
According to the Merck Manual, alpha and beta particles can cause the most damage to your body when they come from radioactive atoms that find their way into your body. The tissue in direct contact or very close to the contamination radionuclide is most affected. Large doses of radiation can cause cells in your body to die, and lower doses of radiation may just stop cell regeneration.
Cell Damage and Regeneration Stoppage
The very low dosage of radiation used in diagnostics shouldn't cause any cellular damage. The Merck Manual website states only certain, directed radiation might cause cell damage and temporary stopping of cell regeneration. Fluoroscopically guided procedures like endovascular reconstruction can damage healthy tissue near the target site.
Cell Regeneration on Children
The biological effects of radiation are most acute with children, because children tend to have more cellular growth and cell regeneration is most harmed by radiation. According to the Jefferson Lab website, low doses of radiation may have no effect on cell regeneration, but moderate doses may cause some cell regeneration to stop, which can be caught up after exposure to the radiation stops. High doses may cause permanent damage resulting in the precursors to cancer.
Radiation Sickness
The United States Nuclear Research website says that ionizing radiation, which could cause cancer, may not show symptoms until years later. By then, other factors such as chemical carcinogens may be a contributing factor. Radiation sickness including nausea, headaches and fever and development of cancer can only be directly attributed to radiation poisoning in a catastrophic event such as the atomic bomb dropped in Japan in World War II.
