According to a study led by Andreas Stohl the Norwegian Institute for Air Research, twice as much radioactive cesium-137 _ a cancer-causing agent _ was pumped into the atmosphere than Japan had announced, reaching 40 percent of the total from Chernobyl. The French Institute for Radiological Protection and Nuclear Safety found 30 times more cesium-137 was released into the Pacific than the plant's owner has acknowledged.
http://www.stltoday.com/news/world/no-man-s-land-attests-to-japan-s-nuclear-nightmare/article_c95d59b0-0f82-5981-b8a1-8c4f040be4d2.html