Fukushima Daiichi nuclear disaster casualties of radioactivity released into the atmosphere was approximately one-tenth as much as was released during the Chernobyl disaster. Significant amounts of radioactive material have also been released into ground and ocean waters. Measurements taken by the Japanese government 30–50 km from the plant showed caesium-137 levels high enough to cause concern, leading the government to ban the sale of food grown in the area. Tokyo officials temporarily recommended that tap water should not be used to prepare food for infants. In May 2012, TEPCO reported that at least 900 PBq had been released "into the atmosphere in March, 2011 alone."
Windscale Piles There was a release to atmosphere of radioactive material that spread across the UK and Europe. The accident was rated a level 5 on the International Nuclear Event Scale. The chimney filters were credited with maintaining partial containment and thus minimising the radioactive content of the smoke that poured from the chimney during the fire. This included a large quantity of tritium, but it proved to be a negligible radiological hazard compared with the other radionuclides. The fire released an estimated of iodine-131, of caesium-137, of polonium-210 and of xenon-133. Iodine-131, which may lead to thyroid cancer, made the most