Paper or plastic—that was the choice you had to make at the grocery store once polyethylene bags were introduced in the 1970s. Those ubiquitous plastic bags are made from polythene, or polyethylene. They are convenient, lightweight and strong—so strong, in fact, that it would take 1,000 years in a landfill for one to decompose. One million polyethylene bags are used throughout the world every minute.
According to data cited in National Geographic, of the more than 500 billion polyethylene bags used each year, millions never make it to the landfill. The wind catches them, and they travel remarkable journeys only to land snagged in a tree, caught in a chain-link fence or stuck in a drainage ditch. Such extended use and subsequent litter led several countries around the world to ban the use of polyethylene bags.
When polyethylene bags block drainage ditches, they can cause widespread flooding. Bangladesh banned the use of these bags in 2002, citing that they had contributed to severe flooding in 1988 and 1998. Both land and sea animals mistakenly ingest them, causing illness and death. Some animals become ensnared in these bags or their residue, and either die from being trapped or become permanently disfigured. When these bags finally do decompose, they deposit chemicals into the soil, rivers, lakes and oceans.
Transport of Alien Species
Small, nonmobile marine species such as bryozoans, barnacles, polychaete worms, hydroids, crabs and mollusks colonize on plastic and are transported with the ocean current to new locations—where these new species can potentially upset and destroy the ecosystem.
Polyethylene is a suspected human carcinogen, or cancer-causing agent. In studies with mice, polyethylene has been linked to cancer of the colon. When these bags come in direct contact with food, as in packaging, chemicals within the bag can leach out into the food and contaminate it.
Petroleum, a valuable and nonrenewable natural resource, is used to make polyethylene. Manufacturing polyethylene bags releases harmful chemicals into the environment, only to have the product being manufactured end up as one of the top sources of litter throughout the world.