Researchers find high-fructose corn syrup may be tied to worldwide collapse of bee colonies
http://phys.org/news/2013-04-high-fructose-corn-syrup-tied-worldwide.html
The researchers aren't suggesting that high-fructose corn syrup is itself toxic to bees, instead, they say their findings indicate that by eating the replacement food instead of honey, the bees are not being exposed to other chemicals that help the bees fight off toxins, such as those found in pesticides.
Study Finds High-Fructose Corn Syrup Contains Mercury - washingtonpost.com
http://www.washingtonpost.com/wp-dyn/content/article/2009/01/26/AR2009012601831.html
"The use of mercury-contaminated caustic soda in the production of HFCS is common. The contamination occurs when mercury cells are used to produce caustic soda. "