If they were measuring dangerous levels of bioaccumulation then you can be sure we'd hear about it. You'd need to live 1000 years though given the levels we're talking about.
This is not self-evident. Biology is extremely complex and we have a lot left to learn before we can make definitive statements about safety. This idea of 'you can be sure we'd hear about it' places too much of the burden on journalists, random medical researchers, and eventually regulators to suss out what is going on.
As it stands in our system today any awareness we may have about dangers will come far after the danger to us, and then we'll all say a collective 'oops' as we've had to do the last hundred times. Look no further than all the 'I [live near the plant/play on the field/drink the water] and have [cancer/autoimmune/rare disease/etc]' stories that keep coming out year after year.
There's lots of evidence that long-chain PFAS can bioaccumulate across generations. You don't need to live a millennium personally. (Also the effects are disproportionately bad on infants, so you don't need 1000 years of generations either.)
Also we didn't really stop putting them in the water yet...
We are in the stone ages of medicinal and biological understanding. We have no idea what levels or forms of exposure are "safe", not only for humans but the ecosystem as a whole.
As it stands in our system today any awareness we may have about dangers will come far after the danger to us, and then we'll all say a collective 'oops' as we've had to do the last hundred times. Look no further than all the 'I [live near the plant/play on the field/drink the water] and have [cancer/autoimmune/rare disease/etc]' stories that keep coming out year after year.