According to this Washington Post article printed yesterday, high-fructose corn syrup (HFCS) contains trace amounts of mercury (Hg) and lead (Pb). In two different studies, they found that between one-third and one-half of foods containing HFCS have trace amounts of Hg, the worst culprits being dairy, dressing, and condiments. Almost everything that is processed and non-organic contains HFCS. Look at any label of most "foods" that aren't just food, basically anything you find in the middle sections of the grocery store, rather than the good stuff found around the egdes (ie fruits, veggies, milk, eggs, meat). The real problem is that you don't really know what HFCS foods have Hg and which do not.
Mercury exposure in young children can have severe neurological consequences, preventing nerve sheaths from forming properly. Mercury inhibits the formation of myelin, the building block protein that forms these sheaths.
Mercury poisoning's effects partially depend on whether it has been caused by exposure to elemental mercury, inorganic mercury compounds (as salts), or organomercury compounds."