Pet Food Recall Danger to People Food?

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I just saw on the Today Show that the poison found in the recalled pet food is a type banned in the US with no antidote although if detected early enough can be treatable. It is now surmised that thousands of animals have been infected. This leads to trail back to wheat gluten coming from China when a possible contamination could have been during the transportation where rats poison is used on the transportation ships. My question: could this be possible in the transportation of food for human consumption? What is going to be done to prevent that happening I thought the FDA had very stringent rules preventing the importation of tainted food stuff.