Before opening canned beans, meats, fruits, or veggies have you ever thought about the top of the can? Just close your eyes and try to picture the life of the can in your hand. It went from factory to truck to store, and was probably touched by at least 3 different people before making it to the shelf. I don't even want to think about how many customers picked up that same can too. Maybe the can dropped on the floor and a kid picked his nose and then put it back on the shelf.
As if that isn't gross enough, who knows how long that can has been sitting there, just collecting dust and germs. And when you go to open the can, the top always slides into the food, so all that nasty junk becomes part of your dinner.
Here's an idea. Always wash and wipe off the top of your can before you open it. You'll have piece of mind knowing you got rid of all the dirt, and your food will be spared bits of dust and bacteria.
The same goes for soda cans and pet food. They can get just as grimy.