litter

Litter typically refers to waste materials discarded in public places. It includes cigarette butts, food wrappers, bottles, and bags, among other items. Littering is illegal in many jurisdictions and is a target of public-cleanup campaigns. The term litter is also used in ecology to describe the layer of dead organic matter—leaves, twigs, fruit skins—that accumulates on the soil surface. This natural litter layer plays a role in nutrient cycling, moisture retention, and habitat for small organisms.

Environmental effects: Litter can pollute soil and water, harm wildlife through ingestion or entanglement, and contribute to microplastic pollution in oceans and rivers. It can also create aesthetic degradation and social costs for municipalities.

Management and prevention: Approaches include providing adequate waste receptacles, regular street cleaning, laws and fines against littering, public education, and community cleanup events. Waste management policies often focus on reducing packaging, promoting recycling, and designing products to be less prone to becoming litter. Some regions use litter traps in drainage systems and street-sweeping programs to collect litter before it enters waterways.

Measurement and research: Litter is monitored through surveys, debris indices, and environmental impact assessments. In ecology, researchers study litter decomposition rates, the litter layer's thickness, and its influence on soil temperature and microbial activity.