[hcurtiss]

Can you point me to a study showing definitive harm due to bioaccumulation of expected exposure levels? EPAs own page cleverly dodges the issue by saying (1) it can accumulate and (2) high exposure levels can cause harm. But the exposure levels we've seen in the studies evidencing harm are thousands of times higher than any observed bioaccumulation. For me to be concerned about environmental exposure, I'm going to actually need to see some science showing somebody was harmed given the range of expected exposure mechanisms and expected exposure levels.

[littlestymaar]

This line of reasoning is absurd!

We know PFAS levels in the environment can only increase in practice due to their very low degradation rate (hence their “forever chemicals” nickname). So even if these harmful levels aren't being reached now, they will definitely be at some point of we keep pouring them out there. And by that time it would be too late.

You don't wait for someone to be harm before intervening when the harm is likely.

[hcurtiss]

You seem to think there’s piles stacking up all over the place. We’re talking parts per trillion, or smaller. The sun may burn out before we encounter quantities sufficient to be harmful.

[littlestymaar]

This is misinformation.

There are already plenty (literally hundreds) of places where the amount accumulated in the environment already exceeds safe limits (mostly in the immediate vicinity of chemical plants processing them, or fire departments which use them extensively).

You said you cared about science in the first message but you obviously don't.

[hcurtiss]

Still waiting on that study showing harmful effects due to bioaccumulation. Of course acute exposure can be harmful. The same is true of oxygen. The question is whether there are harmful bioaccumulative pathways. I’ve seen no science to support that.