Litter affects the earth by introducing toxic foreign substances into the air and water, posing risks to wildlife and plants, creating aesthetic harm and contributing to the production of greenhouse gases. Litter comes from multiple sources, including commercial offices, residences and construction sites. It also accumulates on streets, in gutters and sewers and on open parcels of land from negligent actions of motorists and pedestrians.
Litter poses short-term and long-term risks to local plant and animal populations and their surroundings. Some types of litter, such as plastic bottles and packaging material, are consumed by individual animals that mistake those substances for food and are seriously injured or die upon ingestion. Litter comes in solid, liquid and vapor form. In liquid form, waste enters waterways and surrounding areas in the form of pesticide residue and runoff from agricultural operations and contaminated rainwater. In the process, it harms plants and vulnerable vegetation by stunting plant growth. Trash also kills or injures animals, particularly smaller species. Small animals often crawl into jars or bottles where they get stuck and cannot feed adequately or escape from predators. In marine environments, debris may smother seabeds and cause the accumulation and dispersal of toxic substances.