Biological Effects of Radiation

Hello, I'm Dr. Ziad Kazzi. I'm a medical toxicologist working with the Centers for Disease Control and Prevention. Scientists have been studying the effects of radiation on the body for over 100 years; so we know quite a bit about how radiation interacts with living tissue. Let's take a closer look at how the amount of radiation our bodies receive, otherwise known as the dose, can affect the cells in our bodies. Once a cell is damaged by ionizing radiation, three things can happen. One possibility is that the cell can repair itself. The cell would then go back to normal. Another possibility is that the damage is not repaired or is mis-repaired, so the cell is altered. This alteration may eventually lead to cancer. The third possibility is that there is too much damage to the cell, and the cell dies. Cell death is not always a bad option. In addition to dose, the health effects of radiation also depend on the dose rate or how fast the dose is received. If a person receives a dose over an extended period of time, the health impact won't be as severe as if the dose were received all at once. If the dose is delivered to a portion of the body, the health impact won't be as severe as if the dose were delivered to the whole body. Individual sensitivity to radiation is also a factor. Children and young adults are more likely to develop the late effects of radiation. Young age increases risk for two reasons: younger people have more cells that are dividing rapidly and tissues that are growing, and they have a longer lifespan ahead of them, giving cancers time to develop. Remember, radiation can affect the body in a number of ways, and the effects of exposure may not be known for many years. For low doses of radiation, there may be no health effects at all. If the dose of radiation is high, medical professionals may perform tests or conduct regular screenings to detect and treat health effects that may appear. For more information on how radiation interacts with the body, please visit our website.