Radiation from Japan following the March 11 earthquake and tsunami is not expected to pose a safety risk to Canadians, Prime Minister Stephen Harper says.

Harper said Tuesday there is no risk of radiation or nuclear fallout coming to Canada.

"I've been in very regular contact with all senior officials of the … various government agencies and departments responsible for monitoring this, and there is no evidence of a scenario that presents any risk to this country in terms of those things," Harper said during a stop in Surrey, B.C., on Tuesday.

The events in Japan aren't expected to expose people in Canada to any more radiation than they would normally receive from natural sources, medical tests and transoceanic travel, Dr. Paul Gully, Health Canada's senior medical adviser, said on CBC's Power & Politics.

"We're monitoring the information from across Canada, working with other agencies, other governments to collect information, analyze it," Gully said. "We've come to the conclusion there's no health risk to Canadians in Canada."

It is natural for Canadians to be concerned when seeing images of destruction from Japan, but no threat is expected to reach Canada including the West Coast, Gully said.

Canadians in Japan should listen to government and emergency officials there, he recommended.

Gully strongly discouraged Canadians from buying potassium iodide tablets from domestic pharmacies, which are often given to people at risk of contamination or who have been exposed to radiation. The compound prevents or reduces absorption of radioactive iodine through the thyroid.

On Tuesday, B.C.'s government told all pharmacies that potassium iodide should not be "dispensed in relation to the radiological situation" in Japan. The Public Health Agency of Canada said it has a stockpile of thyroid-protecting iodide pills, but would not reveal where because of security concerns, CBC's Hannah Thibedeau reported.

The amount in the national stockpile is unknown.

'Concerned and anxious'

Some Canadians have been buying pills in bulk, but that's not necessary in this country because "there is no current risk of radiological … exposure," B.C. Health Officer Dr. Perry Kendall said.

Public demand for potassium iodide has surged but Canadian health officials say bulk purchases aren't needed. (CBC) "I think people are concerned and anxious about radioactive exposure," Kendall said on CBC News Network Tuesday, noting health officials along the U.S. West Coast are coping with similar concerns.

Like Harper and Gully, Kendall said there is no current risk, adding he doesn't see any predictable or foreseeable risk.

Health Canada and the Canadian Food Inspection Agency are assessing the source of food imports from Japan to see if any are from an area close to the nuclear plant. If it appears that food might have come from such an area, then they'll decide if it should be checked for radiation. So far, no food has been checked.

Four nuclear plants in northeastern Japan have reported damage following Friday's natural disaster. Federal and provincial health and environmental officials continue to monitor events in Japan.

The National Emergency Stockpile also includes supplies for emergency field hospitals, trauma kits, quarantine units for up to 300 people, and a "push pack" for terrorist incidents that includes potassium iodide, the antibiotic ciprofloxacin, and nerve gas antidote sets, according to the Ontario Health Ministry's website.

The province's chief medical officer could decide to distribute the iodide tablets to evacuees following a nuclear emergency in Ontario or a bordering area, a spokesperson said.

With files from The Canadian Press and CBC's Hannah Thibedeau