Kids Research Express

. Biological Radiation Effects, effects observed when ionizing radiation strikes living tissue and damages the molecules of cellular matter. Cellular function may be temporarily or permanently impaired from the radiation, or the cell may be destroyed. The severity of the injury depends on the type of radiation, the absorbed dose, the rate at which the dose was absorbed, and the radiosensitivity of the tissues involved. The effects are the same, whether from a radiation source outside the body or from material within. The biological effects of a large dose of radiation delivered rapidly differ greatly from those of the same dose delivered slowly. The effects of rapid delivery are due to cell death, and they become apparent within hours, days, or weeks. Protracted exposure is better tolerated because some of the damage is repaired while the exposure continues, even if the total dose is relatively high. If the dose is sufficient to cause acute clinical effects, however, repair is less li

Radiation, in physics, is the process of transmitting energy through space. Such radiation can consist of waves or particles. Waves and particles have many characteristics in common; usually, however, the radiation is predominantly in one form or the other. Mechanical radiation consists of waves, such as sound waves, that are transmitted only through matter . Electromagnetic radiation is independent of matter for its propagation; speed, amount, and direction of energy, however, are influenced by the presence of matter. This radiation occurs in a wide variety of energies, with visible light about in the middle of the range. Electromagnetic radiation carrying sufficient energy to bring about changes in atoms that it strikes is called ionizing radiation. Particle radiation also can be ionizing if it carries enough energy. Like electromagnetic radiation, which it resembles, it does not require matter for its propagation. Examples of particle radiation are cosmic rays, alpha rays, and beta