The pills are necessary if several conditions are met:
- If a "dirty bomb" explodes;
- If radioactive iodine is used in the bomb instead of other radioactive materials;
- If the employee is close to the explosion when it occurs.
Potassium iodide is the only medication for internal radiation exposure to radioactive iodine.
"Employees are out there in all of these communities nationwide and we wanted to err on the side of caution," said Postal Service spokeswoman Sue Brennan.
