[pfdietz]

What I'd worry about is not PFAs, but excreted drugs. Some drugs (or their byproducts) are persistent, and have been deliberately selected to have biological effects.

I take metformin. This drug is mostly excreted in feces. The dry mass of feces might be 1% metformin for someone taking typical doses. The drug does break down in the environment, but only slowly.

[janice1999]

This is already a known issue and waste water plans have treatments to address some of the impacts. I found an article from 2012 where they specifically talk about cost of addressing the contraceptive pill's impact on British water systems.

https://www.theguardian.com/environment/2012/jun/02/water-sy...

[pfdietz]

But how could such treatments work? The drugs are a wide range of organic chemicals mixed in with the literal crap of sludge, which is also a wide range of organic chemicals. Just how is this supposed to separate out or degrade the drug residues without also destroying the sludge?

[Citizen8396]

PFAS have exceptional properties that make them difficult to degrade, especially when it has been ingested. As a result, exposure to them will lead to bioaccumulation. Wastewater is treated to remove things like metformin, and anything that eludes that can be metabolized normally.

[pfdietz]

WWTPs have not proven successful at removing metformin or its metabolite.

https://www.sciencedirect.com/science/article/pii/S221334372...

Granted, this particular chemical partitions into water, not the solids, so it isn't the best example here.

[486sx33]

Artificial estrogen comes to mind as well