Effects of Radiation Exposure
Radiation affects the body in different ways, but the adverse health
consequences of exposure may not be seen for many years.
-Adverse health effects range from mild effects,
such as skin reddening, to serious effect such as cancer and death.
These adverse health effects are determined by the amount of radiation
absorbed by the body (the dose), the type of radiation, the route
of exposure, and the length of time a person is exposed.
-Acute radiation syndrome (ARS), or radiation
sickness, is usually caused when a person receives a high dose of
radiation to much of the body in a matter of minutes. Survivors
of the Hiroshima and Nagasaki atomic bombs and firefighters responding
to the Chernobyl nuclear power plant event in 1986 experienced ARS.
The immediate symptoms of ARS are nausea, vomiting, and diarrhea;
later, bone marrow depletion may lead to weight loss, loss of appetite,
feeling like you have the flu, infection, and bleeding. The survival
rate depends on the radiation dose. For those who do survive, full
recovery takes from a few weeks to 2 years.
-Children exposed to radiation may be more at
risk than adults. Radiation exposure to the unborn child is of special
concern because the human embryo or fetus is extremely sensitive
-Radiation exposure, like exposure to the sun,
sickness, known as acute radiation sickness (ARS), is a serious
illness that occurs when the entire body (or most of it) receives
a high dose of radiation, usually over a short period of time. Many
survivors of the Hiroshima and Nagasaki atomic bombs in the 1940s
and many of the firefighters who first responded after the Chernobyl
Nuclear Power Plant accident in 1986 became ill with ARS.
People exposed to radiation will get ARS only
radiation dose was high (doses from medical procedures such as chest
X-rays are too low to cause ARS; however, doses from radiation
therapy to treat cancer may be high enough to cause some ARS
-The radiation was penetrating (that is, able to reach
-The persons entire body, or most of it, received
the dose, and
-The radiation was received in a short time, usually
-The first symptoms of ARS typically are nausea,
vomiting, and diarrhea. These symptoms will start within minutes
to days after the exposure, will last for minutes up to several
days, and may come and go. Then the person usually looks
and feels healthy for a short time, after which he or she will become sick
again with loss of appetite, fatigue, fever, nausea, vomiting, diarrhea,
and possibly even seizures and coma.This seriously ill stage
may last from a few hours up to several months.
with ARS typically also have some skin damage. This damage can start
to show within a few hours after exposure and can include swelling,
itching, and redness of the skin (like a bad sunburn). There also
can be hair loss. As with the other symptoms, the skin may heal
for a short time, followed by the return of swelling, itching, and
redness days or weeks later. Complete healing of the skin may take
from several weeks up to a few years depending on the radiation
dose the persons skin received.
chance of survival for people with ARS decreases with increasing
radiation dose. Most people who do not recover from ARS will die
within several months of exposure. The cause of death in most cases
is the destruction of the persons bone marrow, which results
in infections and internal bleeding. For the survivors, the recovery
process may last from several weeks up to 2 years.
a radiation emergency occurs that exposes people to high doses of
radiation in a short period of time, they should immediately seek
medical care from their doctor or local hospital.
Possible Health Effects of Radiation Exposure
on Unborn Babies
exposure of an unborn baby to radiation is referred to as prenatal
radiation exposure. This can occur when the mother's abdomen
is exposed to radiation from outside her body. Also, a pregnant
woman who accidentally swallows or breathes in radioactive materials
may absorb that substance into her bloodstream. From the mother's
blood, radioactive materials may pass through the umbilical cord
to the baby or concentrate in areas of the mother's body near the
womb (such as the bladder) and expose the unborn baby to radiation.
possibility of severe health effects depends on the gestational
age of the unborn baby at the time of exposure and the amount of
radiation it is exposed to. Unborn babies are less sensitive during
some stages of pregnancy than others. However, unborn babies are
particularly sensitive to radiation during their early development,
between weeks 2 and 15 of pregnancy. The health consequences can
be severe, even at radiation doses too low to make the mother sick.
Such consequences can include stunted growth, deformities, abnormal
brain function, or cancer that may develop sometime later in life.
However, since the baby is shielded by the mother's abdomen, it
is protected in the womb from radioactive sources outside the mother's
body. Consequently, the radiation dose to the unborn baby is lower
than the dose to the mother for most radiation exposure events.
Pregnant women should consult with their
physicians if they have any concern about radiation exposure to
their unborn baby.
exposure before birth can increase a person's risk of getting cancer
later in life.
-Unborn babies are especially sensitive to the
cancer-causing effects of radiation. However, the increased risks
depend on the amount of radiation to which the baby was exposed
and the amount of time that it was exposed. For example,
if the radiation dose to the unborn baby was roughly equivalent
to 500 chest x-rays at one time, the increase in lifetime cancer
risk would be less than 2% (above the normal lifetime cancer risk
of 40 to 50%).
Other Risks from Radiation Exposure
-Health effects other than cancer from radiation
exposure are not likely when the dose to the unborn baby is very
-Most researchers agree that babies who receive
a small dose of radiation (equal to 500 chest x-rays or less) at
any time during pregnancy do not have an increased risk for birth defects.
The only increased risk to these babies is a slightly higher
chance of having cancer later in life (less than 2% higher
than the normal expected cancer risk of 40 to 50%).
the first 2 weeks of pregnancy, the radiation-related health effect
of greatest concern is the death of the baby.
The unborn baby is made up of only
a few cells during the first 2 weeks of pregnancy. Damage to one
cell can cause the death of the embryo before the mother even knows
that she is pregnant. Of the babies that survive, however, few will
have birth defects related to the exposure, regardless of how much
radiation they were exposed to.
radiation doses to the unborn baby during the more sensitive stages
of development (between weeks 2 and 15 of pregnancy) can cause birth
defects, especially to the brain.
When an unborn baby is exposed to
large doses of radiation (above the dose received from 500 chest
x-rays) during the more sensitive stages of development (especially
between weeks 8 and 15 of pregnancy), the health consequences can
be severe, especially to the brain. Babies exposed to the atomic
bombs dropped on Hiroshima and Nagasaki during the 8- to15-week
stage of pregnancy were found to have a high rate of brain damage
that resulted in lower IQ and even severe mental retardation. They
also suffered stunted growth (up to 4% shorter than average people)
and an increased risk of other birth defects.
the 16th week of pregnancy and birth, radiation-induced health effects
(besides cancer) are unlikely unless the unborn baby receives an
extremely large dose of radiation.
In the 16- to 25-week stage of pregnancy,
health consequences similar to those seen in the 8- to 15-week stage
could occur, but only when the doses are extremely large (more than
about 5,000 chest x-rays received at one time). At this dose level,
the mother could be showing signs of acute radiation syndrome, which
is sometimes known as radiation sickness.
the 26th week of pregnancy, the radiation sensitivity of the unborn
baby is similar to that of a newborn.
At the 26th week of pregnancy,
the unborn baby is fully developed though not fully grown. Unborn
babies exposed to radiation in the womb during this stage of pregnancy
are no more sensitive to the effects of radiation than are newborns.
This means that birth defects are not likely to occur, and only
a slight increase in the risk of having cancer later in life is
it is important for women who are concerned about radiation exposure
to their unborn babies to consult their physician.
information from this page obtained from the
CDC (Centers for Disease Control)