Plastic bags provide a convenient way to carry goods. The bags may be used again to transport items, but most times the thin plastic sacks are thrown in landfills or are incinerated with municipal waste. An occasional bag is found blowing on the highways or in fields. Some stray bags hang from trees. Only a fraction of the bags produced each year are returned for recycling, according to Californians Against Waste.
Recycling options for plastic bags are limited. While it is possible to recycle bags made from polyethylene into new bags, composite lumber or outdoor fencing or drainage pipe, recycling processes mandate the exclusive use of dry, clean and empty bags. Any bag exposed to food cannot be recycled. This limits the viability of recycling plastic bags. This also makes for volumes of landfill. Bags placed in landfill interfere with "moisture distribution and leachate flow within the landfilled waste," according to the Wisconsin Department of Natural Resources.
The United Kingdom Marine Conservation Society states that plastic bags require 450 to 1,000 years to decompose in the environment. Plastic bags in water never completely break down, according to the Sierra Club. A bag exposed to water turns into a plastic dust composed of polychlorinated biphenyls, also known as PCBs, a known bio-toxin. This toxin enters the food chain that eventually includes human consumption of animals and plants exposed to the PCBs.
While plastic bags, sometimes called film bags, manufactured and labeled as No. 2 and No. 4 polyethylene theoretically can be recycled, the problems associated with the process means few are recycled. The quantity required for economic feasibility is high. The Virginia Department of Environmental Quality puts the feasibility total at nearly 40,000 pounds. Most singles-stream recycling plants refuse to sort bags with other collected trash due to problems with machine jams when bags are processed and the difficulty in sorting the film bags.
Floating plastic bags thrown into landfills or released into the environment enter oceans, tributaries and rivers, where animals ingest the waterborne plastic pellets as food. Sea turtles, which prey on jellyfish, mistake the bags for the fish, according to the NOAA National Ocean Service's Marine Debris Program. Bags become wrapped around birds and turtles, strangling the animal as it grows. Sea birds collect the bag pellets as food for newborn birds and the plastic ruptures the organs of the baby birds.
Trash Fields and Flooding
Plastic bags also create flooding problems. The Wisconsin Department of Natural Resources states the bags clog gutters and sewer grates, leading to flooding. Bags and plastics filtering through the sewers and eventually reaching the ocean contribute to trash fields. The NOAA National Ocean Service's Marine Debris Program confirmed the existence of the Great Pacific Garbage Patch, a trash field made up mainly of plastic waste, including plastic bags and resin created as the bags degrade into pieces. Ocean animals absorb the toxins and ingest the pellets from the trash field.