They filtered out the majority of the other bio-accumulating isotopes. "Trace amounts" of isotopes exist in every single element independent of nuclear power plants.

How about linking to a source that doesn't have a 30 to 15 dollar paywall for non-members? Or at the very least posting the full study instead of straight to the paywall that most people can't afford.

The paper is also from 2020 so it's also missing the most recent information and context in regards to the water being diluted and sent out.

Edit: a user directed me to where I could find the full study, and it can be found here Ultimately the study says there should be additional research into the isotopes found within the tanks beyond the tritium found in them.

I definitely agree additional studying should be done, but even then the article doesn't disagree with releasing the tanks. Instead they would rather wait until the isotopes are more decayed. There is however a risk of tank breach due to possible natural disasters such as tsunamis or earthquakes that would allow these isotopes to be release in a more potent concentration.

So the option is to either release it in lower concentration and diluted water is specific amounts, or hold on to it and hope the tanks don't breach for 60 years.