Mercury toxicity is a major environmental health hazard, and can show up in many different ways including cognitive decline, neurodegenerative diseases, depression, fatigue, cardiovascular issues, and anxiety, among others. Because mercury is fat-loving, the brain (composed of a large percentage of fat) can store this metal in large amounts.
Besides coal, most of the dangerous forms of our mercury exposure comes from fish. Avoiding high mercury fish completely is one of the best things we can do. These include tuna, swordfish, orange roughy, tilefish, seabass, and grouper. Having mercury amalgams removed must be done properly and carefully as you mentioned, and the risks must be weighed compared to the benefits. Finding a environmentally aware dentist is a good starting point.
And for mercury accumulated already, you can work on detoxification of that with a functional medicine physician who can provide a supplement protocol to help with its elimination. In the meantime, eating a diet high in cruciferous vegetables, ample vitamin C, vitamin E, and adequate protein is beneficial for bio-transformation and elimination of heavy metals. Detoxification should always be done under the care of a nutritionally educated healthcare practitioner.
Best!
Zoe