While many things eventually break down after a number of years, Styrofoam is one of the few things that does not biodegrade. Tinfoil also does not biodegrade, while aluminum cans take up to 250 years to completely break down, and sanitary pads last up to 800 years.
Other items have a much shorter life span. For instance, canvas products completely biodegrade in about a year, while cotton gloves are gone in approximately three months. Plywood lasts up to three years and batteries for 100 years before biodegrading. Until items completely break down, they take up space in a landfill and continue to have an impact on the environment.