http://www.health.gov.bc.ca/pharmacare/k-iodide.htmlBackground
As a result of the radiological situation at a nuclear power facility in Japan, pharmacists in British Columbia may be asked by customers to dispense potassium iodide (KI).
Recommendation
Please be aware that British Columbia’s Provincial Health Officer and public health officers and health authorities throughout North America are not recommending stockpiling or dispensing potassium iodide in relation to the radiological situation in Japan.
Rationale
KI may be used in radioactive iodine-contamination emergencies (such as a nuclear accidents) to block the thyroid's uptake of radioactive iodine. It is only of benefit in protecting the thyroid against radioactive iodine 131 (I131).
There is extensive monitoring going on in Japan, internationally and along the west coast of North America. Even though there has been a release of radioactive materials in the immediate area of the nuclear plant in Japan which includes I131, it is not a radiological health concern.
In the event that there is a significant release of radioactive iodine 131, the main impact would be on populations within the vicinity of the reactor in Japan.
Modelling of the most likely scenarios suggest that any release into the atmosphere would take several days to reach BC, by which time it would be so dispersed as to be not considered a health risk.