Littering is the improper disposal of waste materials in public or natural environments, rather than in designated receptacles. This practice encompasses items from discarded cigarette butts to old tires. Whether intentional or accidental, it contributes significantly to environmental pollution across various ecosystems.
Impact on Land and Soil
Litter profoundly affects terrestrial environments, creating visible blight and obstructing landscapes. It can alter soil composition through the leaching of chemicals from discarded items. For instance, cigarette butts release substances like arsenic and formaldehyde into the soil, contaminating it and potentially affecting groundwater. Batteries and other hazardous materials similarly leach harmful compounds, disrupting natural soil processes and hindering plant growth.
The decomposition rates of littered items vary significantly, leading to persistent accumulation. While organic waste like banana peels might decompose within months, plastic bottles can persist for approximately 450 years, and glass bottles essentially never decompose. Polystyrene containers can last over 500 years. This accumulation leads to long-term soil degradation and reduced fertility. The physical presence of plastics in soil can also alter its structure and water retention capacity, impacting plant health.
Impact on Waterways and Oceans
Litter frequently finds its way into aquatic ecosystems, including rivers, lakes, and oceans, often transported by wind and rainwater runoff. Once in water, debris like plastic bags and bottles can create physical obstructions, impeding water flow and damaging sensitive aquatic habitats such as coral reefs and seagrass beds. Chemical contamination also arises as litter degrades, releasing toxins that compromise water quality and harm aquatic organisms. For example, chemicals from cigarette butts can be lethal to fish and other marine life even at low concentrations. Plastic items in marine environments break down into microplastics that permeate the water column and sediment, releasing chemical additives and further polluting the water.
Harm to Wildlife
Litter threatens animals in terrestrial, aquatic, and avian environments. Animals frequently become entangled in discarded items such as plastic bags, fishing nets, and six-pack rings. Entanglement can lead to severe injuries, restricted movement, suffocation, or drowning, particularly for marine mammals, turtles, and seabirds. Discarded fishing gear, often called “ghost nets,” continues to trap and kill marine life for decades after being lost or abandoned.
Ingestion is another danger, as animals often mistake litter for food. Plastic fragments, cigarette butts, and other debris can cause internal injuries, blockages in the digestive system, and lead to starvation or poisoning. Studies have found plastic in the stomachs of dead sea turtles, and birds and marine animals frequently ingest cigarette butts, which contain toxic chemicals like nicotine and heavy metals. Even small organisms at the base of the food chain can be affected by ingesting these toxic substances.
The Pervasive Threat of Microplastics
Microplastics are tiny plastic fragments, generally defined as particles smaller than 5 millimeters, that result primarily from the breakdown of larger plastic litter. These ubiquitous particles are found across all ecosystems, including oceans, freshwater bodies, soil, and even the air. Microplastics readily enter the food chain, with organisms at lower trophic levels, such as zooplankton, ingesting them. These particles can then accumulate within tissues and transfer to higher trophic levels as larger animals consume contaminated prey.
Laboratory studies show that microplastics can even be taken up by plants from the soil, potentially transferring to herbivores and humans through consumption. Beyond physical accumulation, microplastics can act as carriers for other pollutants, including persistent organic pollutants, heavy metals, and pathogens, exacerbating their spread through ecosystems. This interaction can disrupt cellular functions, cause oxidative stress, and potentially lead to reproductive issues in affected organisms, impacting overall ecosystem health.