Fukushima guilty of world's worst sea contamination

A new report shows the Fukushima disaster is responsible for the world's worst nuclear sea contamination.

During the peak of Chernobyl, the Black Sea was registering 1,000 becquerels per cubic meter of water - at Fukushima's peak, it was 100,000 becquerels.

Scientists first believed the ocean would dilute it, but Al Jazeera has learned that dangerous concentrations of radioactive caesium remain.

After the accident, radioactive substances spewed out by the quake-stricken Fukushima No. 1 nuclear power plant have likely spread to western Japan and Hokkaido, according to a team of Japanese, U.S. and European scientists.Their findings were published in the Nov. 14 online edition of the Proceedings of the U.S. National Academy of Sciences.

Japan’s science ministry said radioactive contamination spread only as far west as the areas near the border between Nagano and Gunma prefectures. However, it conceded there was a possibility, albeit small, of contamination west of that line.

Monday, (December, the 5) the Tokyo Electric Power Company (TEPCO) said that around 45 tonnes (45 cubic meters) of water contaminated with radioactive substances caesium and iodine had likely run into the ocean from a gutter into which water had leaked from a condensation.

According to TEPCO manager, the leaked water contained 16,000 becquerels per litre (16,0000,0000 becquerels per cubic meter) of radioactive cesium 134 and 29,000 becquerels (29,0000,0000 becquerels per cubic meter) of cesium 137, surpassing government safety limits by 267 and 322 times respectively.

Power plant workers used sand bags as an emergency way to prevent further leakage, but it could take up to three weeks to know the real amount of leaked radioactive water.

Local media reports said the contaminated water may also contain other radioactive substances such as strontium, known to cause bone cancer in humans.