One of the side effects of technology advances is the inability of nature to decompose substances humans create. For example, polythene used in shopping bags is non-biodegradable -- it doesn't beak down naturally in landfills. Non-biodegradable waste can last for centuries and cause environmental problems that affect more than just the land.
TL;DR (Too Long; Didn't Read)
Non-biodegradable waste sits in landfills -- or as litter in forests, parks, rivers and streams. It also washes into seas and oceans, where it has devastating effects on marine wildlife.
Biodegradation: Microorganisms at Work
When something is biodegradable, soil, air or moisture decompose it so that it becomes part of the land. Bacteria, fungi and other decomposers break down dead organisms in a natural process that keeps dead material from covering the planet. While most biodegradable substances consist of animal or plant material, humans can create products that decompose, such as egg cartons and paper bags. If a company produces biodegradable plastic, decomposers break down the plastic's complex organic molecules into simpler inorganic compounds. In May of 2014, Stanford University scientists and Mango Materials teamed up to develop a biodegradable plastic made from waste methane gas.
Effects on Marine Life
Non-biodegradable plastic containers in oceans and estuaries can harm fish, seabirds and other marine life. Animals that eat plastic can strangle or experience digestion problems. Microplastics, tiny bits of polypropylene or polyethylene, hide beneath the water and pose a risk as well. As of September 2014, Virginia Institute of Marine Science researchers were developing biodegradable microbeads that break down when microbes in seawater consume them.
Effects on the Land
The planet has a limited amount of land, and people waste it when they dispose of non-biodegradable materials. Products that do not decompose naturally may reside in landfills and take up space much longer than biodegradable materials. When people litter, some non-biodegradable trash may not even make it into landfills. Instead, it may make its way into forests, parks, fields, and the sea. Styrofoam, also known as foamed polystyrene, is a non-biodegradable substance that can cause environmental problems when it becomes litter. For instance, styrene, a neurotoxin at high doses, can leach out of polystyrene materials when temperatures climb.