OK, so +20 tons of this Colloid of Hg are in the food grade products each year. Let's for a moment assume we only directly ingest 10% of that, more will be absorbed later as it makes it through our food supply chain.
10% is about 2 tons - 2 US (short) tons = 1814369480 mg by US population (U.S. Census Bureau) 1814369480 mg div 312747141 = ~5.8 mg per person per year Hg toxic ingestion level ~0.1 mcg\kg or 0.005 mg for a 50kg\110lbs person
***Yet the FDA finds these losses of Hg into the Food supply safe. Even though safer less power demanding methods exist.***