Use Reusable Bags Because Plastic Bags Don't Biodegrade
Bio-degradation occurs naturally when microorganisms break down organic materials into things like carbon dioxide and water. Most plastic bags that are commonly used at grocery stores are made from a low-density polyethylene which is a man-made polymer that microorganisms such as bacteria and fungi do not eat. Plastic bags are unappealing to them because the material has a relatively high molecular weight and is resistant to water. Therefore, plastic bags take hundreds of years to biodegrade and in landfills take even longer. The slow biodegrading is one of the main reasons that it is so urgent that we begin using reusable grocery bags in place of plastic bags.
Before polyethylene can biodegreade, it must first break in to smaller pieces via light exposure (photodegradation). This process is not the same as biodegrading because the small pieces of plastic bag that result are still forms of the man-made polymer. These microscopic pieces can be ingested by animals, however, which is obviously harmful for them and can result in death, especially for sea animals as they typically resemble plankton and other favorite eats.
Although plastic bags have only been used in supermarkets for about 30 years, they already pose a huge risk for our environment, especially in the ocean and landfills (where garbage and dirt placed on top of them prevents photodegradation). It's estimated that around 1 trillion plastic bags are produced each year, and over 97% of them enter our waste stream. We can help decrease this plague by beginning to regularly use reusable bags for our shopping.