TOKYO - Fears about contaminated seafood spread yesterday despite reassurances that radiation in the waters off Japan's troubled atomic plant pose no health risk, as the country's respected emperor consoled evacuees from the tsunami and nuclear emergency zone.

While experts say radioactive particles are unlikely to build up significantly in fish, the seafood concerns in the country that gave the world sushi are yet another blemish for Brand Japan. It has already been hit by contamination of milk, vegetables and water, plus shortages of auto and tech parts after a massive quake and tsunami disabled a coastal nuclear power plant.

Setbacks at the Fukushima Daiichi nuclear complex mounted yesterday as the plant's operator, Tokyo Power Electric Co., announced that its president was hospitalized. Masataka Shimizu has not been seen since a news conference two days after the March 11 quake that spawned the destructive wave. Spokesman Naoki Tsunoda said Shimizu, 66, was admitted to a Tokyo hospital Tuesday with high blood pressure.

Contaminated water from the Fukushima plant has begun to seep into the sea, and tests yesterday showed that waters 300 yards outside the plant contained 3,355 times the legal limit for radioactive iodine.

It's the highest rate yet, but Nuclear and Industrial Safety Agency official Hidehiko Nishiyama said it did not pose any threat to human health because the iodine rarely stays in fish or shellfish. There is no fishing in the area because it is within the evacuation zone around the plant.

Radioactive iodine is short-lived, with a half-life of just eight days. It was expected to dissipate quickly in the vast Pacific Ocean.

Other radioactive particles have been detected in the waters near the plant, and some have made their way into fish. Trace amounts of radioactive cesium-137 have been found in anchovies as far afield as Chiba, near Tokyo, but at less than 1 percent of acceptable levels.

"We have repeatedly told consumers that it is perfectly safe to eat fish," said an official with Japan's fishery agency.

Citing dilution in the ocean, the U.S. Food and Drug Administration has played down the risks of seafood contamination.