 Styrofoam can actually leach styrene, which is a carcinogen. So when you go to the deli and they give you hot coffee in a Styrofoam cup, I'm almost surprised it's still legal. Yeah, I would bring a mug, and it creates less waste. All that plastic creates dioxin, so you're saving on that, but it helps your health as well. And one other thing that a lot of people don't think about