5. What type of radiation exposure could occur in a nuclear power plant accident?
If a nuclear power plant does not function properly, radioactivity may be released into the surrounding area by a mixture of products generated inside the reactor ("nuclear fission products"). The main radionuclides representing health risk are radioactive caesium
and radioactive iodine. Members of the public may be exposed directly to such radionuclides in the suspended air or if food and drink are contaminated by such materials.
Rescuers, first responders and nuclear power plant (NPP) workers may be exposed to higher radiation doses due to their professional activities and direct exposure to radioactive materials inside the power plant.
6. What are the acute health effects of radiation exposure?
If the dose of radiation exceeds a certain threshold level, then it can produce acute
effects, such as skin redness, hair loss, radiation burns, and acute radiation syndrome
In a nuclear power plant accident, the general population is not likely to be exposed to doses high enough to cause such effects.
Rescuers, first responders and nuclear power plant workers are more likely to be exposed to doses of radiation high enough to cause acute effects.
7. What long-term effects can be expected from radiation exposure?
Exposure to radiation can increase the risk of cancer. Among the Japanese atomic bomb survivors, the risk of leukaemia increased a few years after radiation exposure, whereas the risks of other cancers increased more than 10 years after the exposure.
Radioactive iodine can be released during nuclear emergencies. If breathed in or swallowed, it will concentrate in the thyroid gland and increase the risk of thyroid
cancer. Among persons exposed to radioactive iodine, the risk of thyroid cancer can be lowered by taking potassium iodide pills, which helps prevent the uptake of the radioactive iodine.
The risk of thyroid cancer following radiation exposure is higher in children and young adults.
8. Which public health actions are most important to take?
Health effects can only occur if someone is exposed to radiation, thus the main protective action someone can take is to prevent exposure. Those closest to the radiation are at greatest risk of exposure and the greater the distance away, the lower the risk. This is why when a nuclear accident occurs, the recommended public health actions involve evacuation and sheltering of those near the site.
These necessary actions depend on the estimated exposure (i.e. the amount of radioactivity released in the atmosphere and the prevailing meteorological conditions such as wind and rain.) The actions include steps such as evacuation
of people within a certain distance of the plant, providing shelter to reduce exposure and providing iodine pills for people to take to reduce the risk of thyroid cancer.
If warranted, steps such as restricting the consumption of vegetables and dairy products produced in the vicinity of the power plant can also reduce exposure.
authorities who have conducted a careful analysis of the emergency situation are in a position to recommend which of these public health measures should be taken.