Cancer and Long-Term Health Effects of Radiation Exposure and Contamination

Button the Health Effects of Radiation
Button Radiation Treatments
Button Radiation Health Information for Specific Groups

Radiation Alert Symbol

People who receive high doses of radiation could have a greater risk of developing cancer later in life, depending on the radiation exposure.


  • People who receive high doses of radiation could have a greater risk of developing cancer later in life, depending on the radiation exposure.
    • Health officials will monitor people affected by radiation emergencies for long-term health effects, including cancer.
    • Follow instructions from emergency officials to limit your radiation exposure.
  • For people who receive low doses of radiation, the risk of cancer from radiation exposure is so small that it cannot be separated from exposure to chemicals, genetics, smoking, or diet.
    • Cancer caused by radiation is not distinguishable from cancer caused by smoking or any other risk factor.

Prenatal Radiation Exposure

  • It is especially important that pregnant women follow instructions from emergency officials and seek medical attention as soon as emergency officials say it is safe to do so after a radiation emergency.
    • A developing fetus is highly susceptible to health effects from radiation exposure because of the rapid rate of cell division.
  • Prenatal radiation exposure occurs when the mother’s abdomen is exposed to radiation from outside her body.
    • A pregnant woman who accidentally swallows or breathes in radioactive materials may absorb them into her bloodstream. From the mother’s blood, radioactive materials may pass through the umbilical cord to the fetus or concentrate in areas of the mother’s body near the womb (such as the urinary bladder) and expose the fetus to radiation.
  • The possibility of severe health effects depends on the gestational age of the fetus at the time of exposure and the amount of radiation it is exposed to.
    • Fetuses are particularly sensitive to radiation during their early development, between weeks 2 and 18 of pregnancy.
      • The health effects to the fetus can be severe, even at radiation doses too low to make the mother sick.
      • These can include stunted growth, deformities, abnormal brain function, or cancer that may develop sometime later in life.
  • Women have an increased risk of fetal miscarriage. Fetuses are less sensitive to radiation during later stages of pregnancy (after 18 weeks).
  • Since the fetus is shielded by the mother’s abdomen, it is partially protected in the womb from radioactive sources outside the mother’s body. This means that the radiation dose to the fetus is lower than the dose to the mother for most radiation exposure events.

Learn more

Page last reviewed: April 4, 2018
Content source: National Center for Environmental Health (NCEH), Emergency Management, Radiation, and Chemical Branch