You've probably heard or read many stories relating to the recent discovery that there may be dangerously high amounts of arsenic in rice and rice products, such as brown rice syrup, rice milk, rice flour, and not to mention rice itself. Notice something? These are ingredients used in a lot of processed vegan foods you'd find at the store.
Don't worry, I'm not going to get all Dr. Oz on you. First off, I'm not a doctor so I can't tell you anything about the science of what arsenic can do to your body (but here's one article that can). Secondly, I'm not going to cause a scene by telling you to avoid these ingredients completely. There is still a good amount of research to be done and questions to be answered.
Instead, I'm simply trying to draw a connection. Vegans (or anyone else with a restricted diet) are notorious for meticulously reading labels, doing lots of research, and asking questions about what's in her or his food. We're conscious of what goes into our bodies for moral and health reasons. It's definitely frustrating that we have to keep adding on to the list of things to be wary of, but it's important to continue evaluating our diets and our food system.
So keep pressing on!