New data presented at the conference in the University of Tokyo (Japan), suggests that the level of radioactivity in the waters of the Pacific Ocean near the plant residues Fukusimskoy remains stable and does not drop as expected. The researchers believe that the cause is some runoff and continuing leakage from the station. Also contribute contaminated sediments and marine organisms. Any serious health risk there, but in the long term disaster still affect fisheries.
|Alas, this delicious yellowtail from the vicinity of Fukushima is not. (Photo by EPA / Everett Kennedy Brown.)|
Recall: March 11, 2011 magnitude 9 earthquake triggered a powerful tsunami that struck the plant "Fukushima-1". On three of the six reactors accident releasing into the atmosphere large amounts of radioactive substances. Then the sea water enters the emergency cooling, and in terms of radioactive contamination of the ocean, this disaster was the largest in history. The new model presented staff Oceanographic Institution, Woods Hole (USA), estimates the loss of radioactive cesium at 16.2 PBq, which is comparable with the level of air pollution.
Radioactive material spread throughout the Pacific Ocean, it is diluted to very low levels. But near the station concentration of cesium-137 is stored in 1 kBq, which is quite a lot compared to the natural background. Moreover, the level of radioactive cesium in the bottom fish also remained unchanged, although a half years have passed.
Obviously, something prevents the reduction of radioactivity. Indeed, an oceanographer Zeta Kanda University of Tokyo Marine Science and Technology showed that the case of three factors. First, the rain washed out the radioactive material out of the ground, after which it falls into the river and into the ocean. Secondly, the leakage from the company itself, is, according to scientists, about 0.3 TBq per month.
But the main cause of pollution stands a third source – sea sediments. About 95 TBq of radioactive cesium found refuge in the sandy bottom near the plant. How he got there, no one really knows. Whether it soaked sand, or the tiny microorganisms that cesium sent to the bottom with their secretions. Organic detritus from rivers could also play a role.
One way or another, but the pollution is affecting the entire food chain, though the level varies from species to species. For example, the mackerel are 25 kBq per kg, octopus and squid, it seems, to avoid infection, and snapper and grouper are infected occasionally. In general, the level of cesium in fish and other marine life in the fall still had begun to decline, reported Tomo Watanabe Department of Fisheries Research Japan.
In 2011, the fishing industry of the country has lost an estimated £ 100 £ 200 billion ($ 1.3? 2.6 billion). Many trades are still closed …
Prepared according to Nature News.