Taking Iodine in a Nuclear Emergency
Public health guide
Taking iodine in a
nuclear emergency
What every family should know – who, when, how much, and when not to take it.
Based on the guidelines of the World Health Organization (WHO 2017) and the US Food and Drug Administration (FDA)
Key concept
What exactly does an iodine tablet (potassium iodide) do?
Iodine is not a general antidote to radiation; its role is limited and specific.
What it does
- ✓It protects only the thyroid gland against “radioactive iodine” by saturating it with safe iodine.
What it does not do
- ✕It is not an antidote to radiation.
- ✕It does not protect against the blast wave, gamma radiation or other radioactive substances.
- ✕It is not a substitute for sheltering or evacuation .
Why it matters
Why the thyroid? Why are children at greater risk?
The thyroid needs iodine to make hormones and cannot tell safe iodine from radioactive iodine.
- 1If radioactive iodine enters the body, it accumulates in the thyroid and raises the risk of thyroid cancer .
- 2The younger the person, the greater the risk; therefore newborns, children and pregnant women have priority.
How the tablet works: it “fills” the thyroid with safe iodine so that there is no room left for radioactive iodine. Excess iodine is excreted in the urine within a few days.
Timing
When should it be taken?
Only when announced officially by the health authorities – never on your own initiative or in advance.
Bestfrom less than 24 hours before to 2 hours after exposure.
Up to 8 hoursUp to 8 hours after exposure, taking it is still reasonable.
After 24 hAfter 24 hours it may do more harm than good.
Duration of effectEach dose works for about 24 hours .
Exact dose
Dosage by age
Potassium iodide (KI) tablet – usually a single dose is enough.
| Age group | KI amount | Pure iodine |
|---|---|---|
| Newborn (birth to 1 month) | 16 mg | 12.5 mg |
| Infant (1 month to 3 years) | 32 mg | 25 mg |
| Child (3 to 12 years) | 65 mg | 50 mg |
| Adolescent and adult (over 12 years) | 130 mg | 100 mg |
• Adolescents over 12 weighing 68 kg or more: full adult dose (130 mg).
• Pregnant and breastfeeding women: 130 mg, only one dose.
• More than the recommended dose has no benefit and increases the risk of side effects.
• Pregnant and breastfeeding women: 130 mg, only one dose.
• More than the recommended dose has no benefit and increases the risk of side effects.
Repetition and duration
How often and for how long?
- 1Usually one dose is enough.
- ↻Repeat the dose only in case of prolonged or repeated exposure and on the instructions of the authorities.
These groups should not receive repeated doses
Newborns • pregnant and breastfeeding women • people over 60
A newborn who has received iodine must be checked for hypothyroidism (TSH test).
Prioritisation
Who has priority?
If iodine tablets are limited, these groups should receive them first:
Children and adolescents
the group most sensitive to radioactive iodinePregnant and breastfeeding women
protecting the mother as well as the foetus or infantYounger adults
especially up to about age 40Safety
Important warnings
- !Iodised salt is not a substitute for iodine tablets. Eating large amounts of salt is dangerous and does not protect you.
- !More is not better. An extra dose only causes side effects.
- !Do not take without an official announcement.
Possible side effects of high doses
Thyroid dysfunction • allergic reactions • gastrointestinal discomfort
Who should be cautious
Adults over 40 usually do not need iodine. People with an iodine allergy or a specific thyroid disease should consult a doctor before taking it.
Most important of all
These measures really save lives
- ✓Shelter in a solid building; close doors and windows.
- ✓Stay away from radioactive dust.
- ✓Remove contaminated clothing, set it aside and wash your body.
- ✓Follow official instructions to evacuate or stay put.
- ✓Do not use contaminated water or food.
Iodine only complements these measures; it does not replace them.