Japan quake: MAF confident no radiation in food imports

Food safety officials say they have no information to suggest that any Japanese food exports to New Zealand have been contaminated with radiation.

The Ministry of Agriculture and Forestry (MAF) said New Zealand imported "very little" food from Japan.

Imports were limited to a small range of specialty products, such as small volumes of seaweed and sake as well as mirin, soy sauce, dried noodles, pickled ginger and wasabi.

"The area affected by the earthquake is not a major food production area, and certainly not a major food exporting region," MAF said. "Japanese officials have said that food production in the affected area has been halted and therefore food from this area would not be available for export."

But MAF -- which now includes the Food Safety Authority -- would work with the transtasman food regulator, Food Standards Australia New Zealand (FSANZ), to monitor the situation.

FSANZ also said there was "negligible risk" of consumers being exposed in Japanese foods sent to Australasia.

In the wake of the Japanese earthquake and tsunami crippling the Fukushima nuclear plant about 300km northeast of Tokyo, officials there have reported abnormal levels of radionuclides in milk from the region where the reactors sit; spinach from Ibaraki Prefecture to the south; canola from Gunma Prefecture to the west; and greens from Chiba to the south.

Shipments of the milk and spinach have been banned.

Experts have said that once radioactive elements that can harm health are released into the outdoors, the subsequent radioactive contamination depends on a vast array of factors: the specific element released, which way the wind is blowing, whether rain will bring suspended radioactivity to earth, and what types of crops and animals are in an exposed area.

The principal elements that have been released from reactors at the Fukushima Daiichi plant are iodine 131 and cesium 137. Cesium is long-lived and travels easily through the food chain, while iodine 131 is much shorter-lived but a severe risk for triggering thyroid cancer in mammals.

Initially, some plants will collect more radiation than others: those with big leaves like lettuce, spinach and other greens will naturally collect more radiation than apples, or potatoes.

A British expert on environmental physics, Dr Jim Smith, at the University of Portsmouth, said it seemed that the radioactive iodine concentrations in some foodstuffs in some areas were very high and there was an indication of significant radiocaesium release.

Bans on sale and consumption would have to be put in place in the affected areas.