Potassium Iodide (KI) tablets may help prevent thyroid cancer in people exposed to radioactive material released during a radiation incident. The thyroid gland is the part of the body that is most sensitive to radioactive iodine. KI tablets do not prevent any other radiation-related cancers. Because radiation-induced thyroid cancers are slow-growing, sometimes taking years to develop, KI tablets may be most effective for children and young adults.
Routine KI Distribution Event – November 16, 2024
SMCHD will hold our annual drive-thru Potassium Iodide (KI) Distribution Event on Saturday, November 16, 2024, from 8:00 a.m. – 4:00 p.m. at the Hollywood Volunteer Fire Department. This event is open to St. Mary’s County residents living or working within the 10-mile Emergency Protection Zone (EPZ) of the Calvert Cliffs Nuclear Power Plant.
Who is Eligible?
St. Mary’s County residents living or working within the 10-mile EPZ (zones 6 & 7). This area includes the following zip codes:
- Mechanicsville (20659)
- Hollywood (20636)
- California (20619)
- Lexington Park (20653)
Registration is required. Forms will be available on-site or can be accessed and printed in advance here. Please bring the completed form with you. For more information, please contact smchd.dpr@maryland.gov
Community members may also bring their expired KI tablets for collection and safe disposal to the event. Free hand-crank solar charging emergency radios will also be provided to community members who receive KI tablets as supply allows.
People should only take KI (potassium iodide) on the advice of public health officials during an active incident.
Risks of KI
While KI is good at preventing thyroid cancer when exposed to radiation, there are still risks you should be aware of as with all medication. The risks of KI are the following:
Less Common
- hives
- joint pain
- swelling of arms, face, legs, lips, tongue, and/or throat
- swelling of lymph glands
With Long Term Use
- burning of mouth or throat
- confusion
- headache (severe)
- increased watering of mouth
- irregular heartbeat
- metallic taste
- numbness, tingling, pain, or weakness in hands or feet
- soreness of teeth and gums
- sores on skin
- symptoms of head cold
- unusual tiredness
- weakness or heaviness of legs
If experiencing any of these side effects, please contact your doctor as soon as possible.
Potassium Iodide (KI) Distribution
The St. Mary’s County Health Department (SMCHD) routinely distributes KI tablets to county residents living or working within the 10-mile emergency protection zone (EPZ) of the Calvert Cliffs Nuclear Power Plant to have on hand in case of emergency.
Who is Eligible?
St. Mary’s County Residents living or working within the 10-mile EPZ (6 & 7). This area includes the following zip codes:
- 20659 – Mechanicsville
- 20636 – Hollywood
- 20619 – California
- 20653 – Lexington Park
Distribution
Potassium Iodide (KI) tablets will be routinely offered to eligible community members. The St. Mary’s County Health Department will issue a notice when the next distribution event is scheduled.
Recommendations for Taking KI Tablets
The following recommendations are for general information purposes. People should only take KI (potassium iodide) on the advice of public health or emergency management officials during an active incident. Click here for the SMCHD Informational Brochure on when and how to take KI (En Español).
In the case of an emergency incident, the community will be notified by the St. Mary’s County Government and St. Mary’s County Health Department via the CodeRED Emergency Notification System as well as through local news, radio, and social media outlets.
A single dose of KI (potassium iodide) protects the thyroid gland for 24 hours. A one-time dose at recommended levels is usually all that is needed to protect the thyroid gland. In some cases, people can be exposed to radioactive iodine for more than 24 hours. If that happens, public health or emergency management officials may tell you to take one dose of KI (potassium iodide) every 24 hours for a few days.
Infants
Infants have the highest risk of getting thyroid cancer after being exposed to radioactive iodine.
- When recommended by public health/emergency officials – Infants, including breast-fed infants need to be given a single dose of KI (recommended dosage for infants)
- More than a single dose may lead to later problems with normal development
- In cases where more than one dose is necessary, medical follow up with your pediatrician may be recommended
- Liquid dosing instructions
- Children over 1 month through 3 years of age—32 mg once a day, until there is no longer a significant risk of radiation
Children
When recommended by public health/emergency officials – All children who are internally contaminated (or likely to be) with radioactive iodine should take the recommended dose of KI, unless they have known allergies to iodine.
- Children 3-17 years of age (less than 154lbs )—65 mg once a day, until there is no longer a significant risk of radiation
Adults (18-40)
When recommended by public health/emergency officials – Adults between the ages of 18 and 40 years who are internally contaminated (or likely to be) with radioactive iodine should take the recommended dose of KI. Young adults are less sensitive to the effects of radioactive iodine than are children.
- Adults or teenagers 154 lbs + —130 mg once a day, until there is no longer a significant risk of radiation
Pregnant Women
Because all forms of iodine cross the placenta, pregnant women should take KI during an active incident to protect the growing fetus. Pregnant women who are internally contaminated, or likely to be, should take only one dose of recommended KI for adults.
Breastfeeding Women
Women who are breastfeeding who are internally contaminated, or likely to be, should take only one dose of recommended KI for adults.
Adults (40+)
Generally, adults older than 40 years should not take KI. Public health/emergency officials may recommend KI for this group if the emergency event/contamination of radioactive iodine is expected to be severe.
- Adults older than 40 years have the lowest chance of developing thyroid cancer or thyroid injury after contamination with radioactive iodine
- Adults older than 40 are more likely to have allergic reactions to or adverse effects from KI
- Follow recommendations from public health/emergency officials for this specific age group
Pets
Consult your veterinarian before giving your pet Potassium Iodide (KI), keeping the following in mind:
- KI only protects the thyroid from radioactive iodine. It does not shield against other harmful radiation that may be released during a nuclear event.
- Pet decontamination may still be needed.
- Correct dosing is crucial. Like all medications, improper dosing can be harmful to your pet. Speak with your veterinarian about appropriate dosage recommendations.
- Young, growing animals are more vulnerable to radiation. Radiation exposure poses the greatest risk to younger animals due to their developing systems.
- Timing is critical. KI must be administered before or within 4 hours of exposure to be effective.
- KI availability for pets may be limited. Most veterinarians and pharmacies do not routinely stock KI, though they may begin to do so if demand increases. KI can also be specially ordered through your veterinarian or local pharmacy.
- Do not give KI to pets sensitive to iodine. Always confirm with your veterinarian if KI is appropriate for your pet, especially if they have an iodine sensitivity.
For more information, please contact your veterinarian.
Additional Resources
- SMCHD Potassium Iodide Distribution Form
- St. Mary’s County Local Public Health Corps
- St. Mary’s County CodeRED Emergency Notification System
- Calvert Cliffs Area | Nuclear Emergency Plan
- Exelon Generations | Emergency Planning for the Calvert Cliffs Nuclear Power Plant
- Maryland Department of Emergency Services | Nuclear & Radiological Emergencies
- FDA | Potassium Iodide (KI) in Radiation Emergencies Questions & Answers
- FDA | Liquid Dosing Instructions
- CDC | Facts About Potassium Iodide (KI)