Tritium water is being dumped or planning to be dumped into the sea. This may cause problems in high quantity as it is radioactive and although it is low levels the substance breakdown into different chemicals. There is approximately a 12-year half-life. One of the chemicals is helium (a gas).[EPA Fact About Tritium, https://www.nrc.gov/docs/ML0609/ML060960589.pdf] So if you eat foods from the sea or get tritium water into your body the result may cause gas bubbles to form. It would probably be similar to the bends that divers can get with gas bubbles foam after rapid decompression. Tritium water does occur naturally and the body can handle small doses but not complete body water replacement. If levels become too highly concentrated then the body cannot remove the gasses from the blood, brain and organs.
Please see more detail on my full page about the tritiated water issue.
https://www.dragon-net.co.uk/dangers-of-tritiated-water-dumped-in-the-sea/