TOKYO (Reuters) - Environmental group Greenpeace on Thursday slammed Japan's "continued inadequate response" to the nuclear disaster at a power plant after new data showed seaweed radiation levels 50 times higher than official limits.
The new information raised "serious concerns" about long-term risks from contaminated seawater, it said, more than two months after the Fukushima-Daiichi plant was destroyed by an earthquake and tsunami.
"In contrast, Japanese authorities claim that radioactivity is being dispersed or diluted and are undertaking only limited marine radiation monitoring," it said.
"Our data show that significant amounts of contamination continue to spread over great distances from the Fukushima nuclear plant," a statement quoted radiation expert Jan Vande Putte as saying.
"Despite what the authorities are claiming, radioactive hazards are not decreasing through dilution or dispersion of materials, but the radioactivity is instead accumulating in marine life. The concentration of radioactive iodine we found in seaweed is particularly concerning, as it tells us how far contamination is spreading along the coast, and because several species of seaweed are widely eaten in Japan."
(Writing by Nick Macfie)