Update: Early on Saturday, Japan announced that radiation was detected in spinach and milk produced near the Fukushima nuclear plant. While the levels were low enough to not pose a long-term threat to human health, they were above the national safety level, so the Japanese government has stopped sales of food products from near the damaged plant.

It was the first report of radiation contamination in food since the March 11 tsunami damaged the power plant.

As the plumes of nuclear smoke first began to rise over Japan’s destabilized Fukushima nuclear plant, so did concerns that food coming from that country might contain radioactive material.

Increased Precautions

Several countries are taking steps to ensure the safety of their food supplies. In Asia, South Korea, Indonesia, Thailand, Malaysia, India, Singapore and the Philippines have all begun to monitor Japanese food imports.

Hong Kong’s Centre for Food Safety (CFS) has ramped up its surveillance of food coming from Japan as well. Beginning March 12, CFS began testing fresh imported products such as fruits, vegetables, milk and meat, for radiation. As of Friday, 151 foods had been tested, and none had been found to be contaminated.

And while no levels of radioactivity have been detected, fresh food from Japan is being refused in some areas.  Some sushi restaurants in Asia have reportedly taken Japanese seafood off the menu, and Italy has banned Japanese imports altogether.

The U.S. imports only limited amounts of food from Japan and in a statement Thursday, the U.S. Food and Drug Administration (FDA) said it “has a very robust screening process in place at the ports to monitor incoming products.”

The FDA also assured consumers that it is “working with the Japanese government and other U.S. agencies to continue to ensure that imported food remains safe.”

Meanwhile, U.S. Department of Agriculture Secretary Tom Vilsack echoed that message about foods imported from Japan, as well as food safety at home.  “I know that there are many questions Americans might have about the terrible tragedies in Japan,” he said. “I want to reassure the American public that at this time we have no reason to suggest that any of our meat, poultry, dairy or processed egg products are unsafe for consumption due to the recent events in Japan.”

President Obama also has said there is little chance nuclear radiation could reach the United States and affect our food supply.  “We do not expect harmful levels of radiation to reach the West Coast, Hawaii, Alaska, or U.S. territories in the Pacific.  That is the judgment of our Nuclear Regulatory Commission and many other experts,” he said in a statement released Thursday by the White House.

Vilsack emphasized that imports will continue to meet U.S. safety standards: “We monitor and inspect imports to insure compliance with those standards. Should any risk with imports arise, we have procedures and processes in place to identify problems and deal with them.”

The Potential Danger

If radiation were to contaminate Japanese food, fresh produce would most likely be affected first. “The surface of foods like fruits and vegetables or animal feed can become radioactive by deposit of radioactive materials falling on it from the air or through rain water,” says a release from the World Health Organization (WHO) and the United Nations’ Food and Agricultural Organization.

Radioactivity can then build up inside food sources, such as animals or fish, as radionuclides settle into soil or water, according to WHO.

The presence of these harmful particles in soil was what led to the contamination of cow milk following the nuclear explosion at Chernobyl in 1986, after cows ate grass grown in radioactive soil. Some fear that the Fukushima leak could lead to a similar threat, and at the least shake public confidence in some popular Japanese products, such as wagyu beef.

No Cause for Concern So Far

As of now, however, experts say there is no need to worry about the safety of any of Japan’s foods.

“In Chernobyl, there wasn’t much of a prevailing breeze, so Iodine-131 [the harmful element in nuclear material] settled not too far away,” says Dr. Richard Morin, professor of Radiologic Physics at the Mayo Clinic and Chairman of the American College of Radiology’s Safety Committee.

In Japan, however, Morin says there is a prevailing breeze over the nuclear plant that, as long as it continues, will cause harmful particles to dissipate into the atmosphere rather than settle in fields.

In the meantime, Japan’s food producers are not likely to be doing much exporting, as they deal with damaged facilities, power outages, fuel rationing and transportation difficulties in the aftermath of the earthquake and tsunami. Destruction from these disasters halted most fish production before the nuclear leak occurred and much earlier events — including outbreaks of avian flu and foot-and-mouth disease last year — had diminished the Japanese meat export trade.

For the time being, any possible future dangers from Japan’s nuclear leak remain insignificant compared with the immediate public health threats the Japanese people face, including impending cold weather, food shortages, power outages and a water supply that could become contaminated with harmful pathogens borne by floodwaters.