How Long Does Litter Stick Around?

Degradation Times

• Cigarette butt – 5 years
• Plastic grocery bag – 20 years
• Tin can – 50 years
• Styrofoam cup – 50 years
• Aluminum can – 200 years
• Plastic bottle – 450 years
• Glass bottle – 1 million years

What’s the problem?  Won’t litter biodegrade?
To answer this, we must first look at the difference between biodegrading, composting, and breaking down.

A biodegradable item, according to the U.S. Federal Trade Commission (FTC), will completely break down and return to nature (i.e. decompose into elements found in nature) within a reasonably short period of time after customary disposal.  In other words, an item must be able to fully break down and then be consumed and digested by microorganisms, leaving no trace it once existed.  These products are often plant-based items derived from corn and potato starch, like a biodegradable cup or bag.

A compostable item, according to the FTC, must be able to break down, or become part of, usable compost in a safe and timely manner in an appropriate composting facility or home compost pile.  Healthy compost, when returned to the earth, improves soil health by adding in beneficial nutrients and microbes.  This means items that leave a residue, like plastics or metals, cannot truly be composted.  Fruit, vegetable, and yard scraps are ideal compost materials.

The most common fate for litter, especially plastic and styrofoam, is to break down into smaller and smaller pieces of microtrash that continue to persist in the environment indefinitely.  These items often contain chemicals, dyes, and metals that leach into the environment as they breakdown, adding toxins to soil and water.  Small animals and filter feeders consume countless pieces of microtrash that they cannot distinguish from food and are unable to digest.

So while it’s true that some types of litter will eventually biodegrade or compost, many will remain in the environment for hundreds or thousands of years if not forever.

Don't Feed the Wildlife!

While that shiny, brightly colored piece of rubbish might look like a tasty meal to an unsuspecting critter, consuming trash can severely harm an animal.  Eating trash can easily lead to choking or suffocating.  If eaten, there is no nutritional value in trash, and animals cannot digest it.  The lucky ones may pass a piece of litter unharmed, but most risk toxic chemicals entering their systems, internal organ abrasion, or blockages.  In extreme cases, animals consume so much litter that they become filled with it, are unable to consume a normal diet, and eventually starve to death.

Consumption isn’t the only way litter can be damaging to wildlife.  Aquatic animals can become tangled in abandoned rope, nets, or fishing lines, which render them unable to swim, fly, or otherwise mobilize.  This means they cannot defend against predators, acquire food, or mate.

Litter and the Food Chain

Consuming litter is detrimental from the beginning of the food chain to the end.  When an organism (e.g. a plankton) consumes a toxic substance (e.g. chemicals released by degrading trash), the toxin accumulates in the organism’s body.  This is called bioaccumulation.  The organism (plankton) is eaten by a predator (e.g. a minnow), and the toxins enter the body of the minnow.  Because the minnow eats lots of plankton, the minnow accumulates lots of toxins, thus increasing the toxic concentration in its body.  The predator (minnow) is then eaten by a higher level predator (e.g. a trout), and the toxins enter the body of the trout.  Because the trout eats lots of minnows, the trout accumulates lots of toxins, thus increasing the toxic concentration in its body.  This is called biomagnification.  This continues up the food chain to the top level predator, such as a heron or a human, which now consume large amounts of the toxin.  What was once a small concentration of a toxin in the water is now a large level of a toxin in an animal.

Note:  This illustration is for demonstration purposes only and should not be considered scientifically accurate.

What about food waste?  Is that litter too?

Yes.  Food waste, like apple cores, banana peels, stale bread, etc., is considered litter for several reasons. An animal’s natural diet does not consist of food scraps from humans, so their digestive systems have not evolved to eat these foods.  Providing wildlife with “people food” discourages their natural foraging habits and increases dependence on human-given meals.  In urban areas, food litter may attract wildlife into human territory, potentially bringing disease carrying nuisance animals into close contact with humans.  On the road, food scraps bring animals into close proximity to moving vehicles and increases the risk for a wildlife-vehicle collision.  Most state laws in the U.S. prohibit throwing anything from a car window, including food.