Some of our problems begin with Styrofoam. Expanded polystyrene foam is 98% air. This means that when Styrofoam is left in our environment, it fills with rainwater and creates mosquito breeding grounds. If it gets in the ocean pieces will break up and marine life would eat it. Long-term exposure to styrene also increases the risk of leukemia and lymphoma. This exposure also harms the liver, kidneys, and stomach.