It's extremely difficult to do such a study because the entire system is just so complex and there's no way to control for many of the variables. There have, h

It's extremely difficult to do such a study because the entire system is just so complex and there's no way to control for many of the variables. There have, however, been limited studies about bioaccumulation of tritium in phytoplankton and how it can move up the food chain [1]. As another poster said, tritium decays by beta radiation which isn't necessarily harmful but if it accumulates in the food chain, it might be dangerous (just like heavy metals and fish, for example). Tritium's half life is about 12 years so its not inconceivable. It's a different environment but you can probably draw some conclusions about the impact/spread of radioactive particles by looking at Chernobyl. Edit: [1] http://www.ncbi.nlm.nih.gov/pubmed/22863967 http://www.ncbi.nlm.nih.gov/pubmed/22863967