Just when you thought "food" couldn't get any less nutritious, it does in quite an alarming way.
That lovely viscous substance commonly known as HFCS has been found to contain detectable levels of mercury in it. High fructose corn syrup is in practically everything, which means... so is mercury.
Mercury, for the elementally challenged, is a naturally occurring substance that can cause serious neurological damage when eaten in large quantities. Considering that high fructose corn syrup is in just about every food carried in local supermarkets, you can see how easy it'd be to consume high levels of this element.
Check out this this list that shows common foods with the level of mercury detected in them. Quite scary! Quaker Oatmeal (really random, right?) tops the list with the highest detected levels.