Likely, because they will be our generation's lead poisoning, but the lead is everywhere and in everything and will be around for generations to come.

To this list I'd like to add hyper-palatable foods and possibly chemical dependence as the pharmaceutical/supplement business convinces more and more people that the latest magic substance will fix whatever ails you. Especially when the "ailment" is modern society being difficult to exist in and SSRI drugs are the only thing that seem to keep you "functional" in said society.

I say this as a Zoloft patient but there are endless supplements and drugs intended to make our lives better by some metric. "Not satisfied with life? Turn down your emotional intensity with mood stabilizers so you can continue going to your dead end job, just to barely make it every month!"

Add world-wide famines, wars and crumbling ecosystems on top of that.