Japan’s government has backed a plan to dilute the processed water and release it into the sea.

The government says the process meets international standards, and it has been endorsed by the International Atomic Energy Agency.

“Releasing into the ocean is done elsewhere,” IAEA’s director general, Rafael Mariano Grossi, has said. “It’s not something new. There is no scandal here.”

The release is not likely to begin for at least two years and will take decades.

A government spokesman, Katsunobo Kato, said the dilution would reduce tritium levels to well below standards set domestically and by the World Health Organization for drinking water, with IAEA supervision. //

Environmental groups like Greenpeace, which opposes nuclear power, say radioactive materials like carbon-14 that remain in the water can “be easily concentrated in the food chain”.

They allege that accumulated doses over time could damage DNA, and want to see the water stored until technology is developed to improve filtration. //

But “there is consensus among scientists that the impact on health is minuscule”, he told AFP.

Still, “it can’t be said the risk is zero, which is what causes controversy”.

Geraldine Thomas, chair of molecular pathology at Imperial College London and an expert on radiation, said tritium “does not pose a health risk at all – and particularly so when you factor in the dilution factor of the Pacific Ocean”.

She said carbon-14 was also not a health risk, arguing that chemical contaminants in seawater like mercury should concern consumers more “than anything that comes from the Fukushima site”.

On eating Fukushima seafood, “I would have no hesitation whatsoever,” she added.