Uncertainty and a growing unstable nuclear threat in Japan have forced a Canadian relief team to return to Vancouver.

The Canadian Medical Assistance Team (CMAT) says it has been stuck in Tokyo for several days, unable to reach the hardest-hit areas in the northeastern part of the country because of the escalating risks of a nuclear disaster at several power plants.

A spokesperson for CMAT says they are not officially equipped for a nuclear emergency.

Calling the situation frustrating, Bill Coltart says radiation levels might rise to a potentially dangerous level and they don't want to endanger the team's health.

"Emergency operations were being suspended due to excessively high radiation in the area. Based on this and our further discussions with the United Nations on site coordination centre in Tokyo we made the decision it's just too unsafe to have our team continue operating there," he told CTV News in a telephone interview from Tokyo Tuesday night.

CMAT says it will continue to prepare and stage its response from facilities in Metro Vancouver and Seattle, WA.

Members hope to return to Japan to continue relief efforts when the situation stabilizes. The agency is in the process of moving equipment and supplies from its warehouse in Toronto to the West Coast.

It is also continuing efforts to raise money for a high-volume water purification system to provide clean drinking water to cities like Sendai.

The CMAT field team is comprised of three B.C. paramedics, a Vancouver search and rescue expert and a Toronto-based photojournalist.

Meanwhile, several Australian and New Zealand search and rescue workers were exposed to low levels of radiation after their helicopter was forced to land at Fukushima airport, about 20 kilometres outside the exclusion zone around the Fukishima Dai-ichi nuclear plant.

Australia's prime minister says four members were found to have "very low levels" of contamination on their boots. The leaders of both countries said they are satisfied the health of the workers is not at risk.