Yeah, I have heard this too. Or some other problem like some sickness coming on and then plunging the person down enough to where the mercury already in them, then tends to keep them down and begins to cause chronic poisoning symptoms.

One guy I know of, had something wrong with his stomach (from an accident) and that's when he became mercury toxic.
No doubt the mercury was already there, but he may not have been as suseptible to it. Once he was brought down low enough by other means, he then became chronically mercury poisoned and had all the symptoms. So he then had to get his amalgams replaced and had to chelate.

physical/emotional stress can do it. My trigger was getting braces on my teeth at age 15. That was it, all the fighting my body had previously been doing with the mercury couldn't cope anymore and I was down and stayed down.

This is why I think diet is important because it can give the body at least "one" avenue it can lean on to handle better the stresses of other illnesses and toxicities. Candida is an opportunist and makes a bad situation even worse in my opinion. So it was something i was able to grab onto and stabilise and improve my situation more.

My symptoms also worsen during stress and seem to cause a movement of toxins at the sametime.