How do forever chemicals affect our health, if their main characteristic is not interacting with other chemicals?

Question

When I hear talking about forever chemicals, they are usually described as “chemicals are not affected by naturally occurring reactions, and that accumulate in the bodies of living beings”. By accumulating, they cause all sorts of health issues.

What I don’t understand is how they cause these health issues. If these chemicals do not participate in regular reactions, how do they cause issues?

I am not claiming that the research in the subject is wrong, I am missing the link between “these things don’t react with anything” and “these things still cause all sorts of health problems”.

In: 469

Answer 1

Depends somewhat on the specific chemical, but the general idea is that the chemical is stable relative to most naturally occurring compounds so does not react in nature with most of what it might encounter. Some of the chemicals can react with particular conditions or compounds that themselves are fairly stable, and in some cases, that is one possible reason they can be a problem (by destroying or modifying chemicals required for body functions).

Often, though, the problem compound is similar in form to some other useful compound (like, say some sort of hormone), at least in part, so it will interact with the things normally targeted by the hormone (or whatever compound it is similar to). It is a problem because it can either trigger responses that should not be turned on, or interfere with mechanisms (by blocking receptors) that ought to be initiated by the expected and useful compound being mimicked.

To understand this fully, you have to understand that many organic molecules are fairly large and made up of different functional groups at different locations on the larger molecule, and thus have a fairly specific shape and reactivity that varies from region to region in the molecule. Like a key only works for a matching lock, many organic compounds only “fit” together with its target, and it is the only compound produced by the body which will fit. Having a similar shaped compound from elsewhere that can fit the lock, well, that can be a problem and disrupt the way the system ought to be working, by locking, or unlocking, a chain of processes.