Watching the World Garbage in the Sea A glass bottle thrown into the sea will take a thousand years to decompose and disappear. Paper tissues take three months to decompose, and matchsticks, six months. Cigarette butts will pollute the sea for from one to 5 years; plastic bags, 10 to 20 years; nylon articles, 30 to 40 years; cans, 500 years; and polystyrene, 1,000 years. These estimates are just some of the information provided by Legambiente, an Italian environmental association, to encourage bathers to be ecologically - minded when they go to the beach.