As tritium makes its way up the food chain it may become more concentrated. Diseases such as Down s syndrome and heart disease have been associated with tritium exposure in community health studies. Strontium-90 is a radioactive isotope of the element strontium, a substance that is chemically much like calcium. Thus, this isotope tends to concentrate in bone, where it can induce bone cancer. Levels of strontium in soil and food vary geographically.
Strontium resembles and acts like calcium.
Radioactive strontium is biologically retained in human bones. Leukemia was caused more readily by continuous low doses than by a single high dose. High doses caused disproportionately more bone cancers than low doses. There is also evidence for a weakening of the immune system. The major health hazard associated with ingestion of radioactive strontium is bone cancer, although leukemia and other bone related cancers resulting from irradiation of the bone marrow can also be induced.