into your bones and stays there for years and remains radioactive tore 600 years and causes bone cancer and leukemia and other malignancmalignancies. it remains radioactive 600 years. the half-life is the amount of time it spends in the body before it s excreted. cesium irradiates the entire body and causes a variety of different cancers. plutonium is primarily a cause of lung cancer. it s dangerous when it s inhaled in the lung. and for more on what the earthquake has done to japan s nuclear reactors you can reach us online. you ll find the answers to a number of your questions at cnn.com. of course, there are only so many answers after human tragedy of this magnitude. what does one say to families who have lost their loved ones?