Health Canada is deploying nine more radiation-monitoring devices to B.C. in the wake of Japan's nuclear reactor crisis.

The devices will be in addition to six units already in place along the B.C. coast, Health Canada said.

The extra deployment is not due to any increased risk faced by the Canadian population, said Dr. Paul Gully, a Health Canada senior medical advisor.

"The assessment is that the risk to Canadians in Canada is negligible and will remain negligible, even in the worst-case scenario," Gully told CBC News Friday.

A measurement of air flow across the Pacific has indicated the first emissions from Japan would have already reached B.C.

The only radiation detected in B.C. so far has been the normal amount of ambient radiation Canadians would be exposed to on any given day, Gully said.

No passenger or food screening

Gully said the increased monitoring capability is intended to be able to provide more information to the public.

"We do want to reassure Canadians that we do have information," he said. "So, the more monitors we have the more information we have."

Gully said Health Canada has not decided exactly where the two-metre-high units will be placed, but that they would possibly be in a mix of urban and agricultural areas.

Exact locations would not be revealed, he said, as the units are valuable and highly sensitive.

The monitoring devices send received data immediately to Ottawa, where results are analyzed.

Gully also said that Health Canada has been in contact with a number of other federal agencies, including Transport Canada and the Canadian Food Inspection Agency, regarding radiation screening of passengers, cargo and food from Japan.

No screening is currently taking place and none is required, he said.

With files from the CBC's Lisa Johnson and Alan Waterman