Hazardous effects of plastic wastes on land biodiversity: A review

Plastic pollution is ubiquitous throughout the world’s ecosystem. Increase in the world’s plastic production and use, inefficient recycling, indiscriminate disposal, synthetic nature and non-biodegradability of plastics have made it a considerable threat to biodiversity. The impact of plastic wastes on humans and the environment is becoming apparent. However, information on the impacts of plastic wastes on biodiversity is mostly directed towards marine environment with scarce information on land biodiversity although terrestrial environment is the major source of marine contamination. Terrestrial plastic waste contaminants are derived from long term used plastic containers and single-use plastic products, which are introduced by anthropological means, flood water, sewage and wind dispersal. Gradual breakdown of large plastic wastes give rise to microplastics, which increase its abundance in the environment. Plastics threaten wildlife in terms of entanglements, ingestion and chocking, which often results in loss of body parts or mortality. Plastics as vectors of invasive species in marine ecosystem have been widely established. Although not much is known on the importation of invasive species on terrestrial ecosystem by plastic wastes, there is possibility that plastic waste can be a potential vector of terrestrial alien species. Contamination of soil with microplastics alters soil habitats and disturbs the natural biophysical properties of the soil environment that leaves a negative impact on soil biota by reducing their activities and indirectly affecting food production. Accumulation of plastic wastes provides breeding ground for disease vectors, which has contributed to increased prevalence of emerging infectious diseases. This review examines the impact of plastic wastes on terrestrial biodiversity as it affects soil organisms, land animals and breeding of disease vectors.