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.