Litter consists of waste products that have been disposed improperly, without consent, at an inappropriate location. Litter can also be used as a verb. To litter means to drop and leave objects, often man-made, such as aluminum cans, cardboard boxes or plastic bottles on the ground and leave them there indefinitely or for others to dispose of as opposed to disposing of them properly.
Large and hazardous items of rubbish such as tires, electrical appliances, electronics, batteries and large industrial containers are sometimes dumped in isolated locations, such as national forests and other public land.
It is a human impact on the environment and remains a serious environmental issue in many countries. Litter can exist in the environment for long periods of time before degrading and be transported large distances into the world's oceans. Litter can affect quality of life.
Cigarette butts are the most littered item in the world, with 4.5 trillion discarded annually. Estimates on the required time for cigarette butts to break down vary. They range from five years to 400 years for complete degradation.