This expose is not a lesson, but an interesting read about a German company illegally selling Chinese honey that was adulterated to US customers and how they were getting by US regulators. One choice passage: "The 50-gallon drums would be relabeled in these countries and sent on to the U.S. Often the honey was filtered to remove the pollen, which could help identify its origin. Some of the honey was adulterated with rice sugar, molasses, or fructose syrup..."
"In a few cases the honey was contaminated with the residue of antibiotics banned in the U.S.... Testing revealed one container was contaminated with chloramphenicol, an antibiotic the U.S. bans from food. Chinese beekeepers use chloramphenicol to prevent Foulbrood disease, which is widespread and destructive. A deal was made to sell the contaminated honey at a big discount to another customer in Texas, a processor that sold honey to food companies."
There's no way of not knowing everything you eat, whether it's contaminated with antibiotics, pesticides or harmful bacteria. But you can limit so much of your exposure by eating whole foods you cut and clean or cook at home after washing thoroughly.