Bioaccumulation and toxicity of polystyrene nanoplastics on marine and terrestrial organisms with possible remediation strategies: A review

Most of the things we see around are made up of plastics. From stores to homes, it has made its way into each economic sector. The most extensively used is polystyrene which has been widely used in the food industry, cutlery, industrial packaging, building insulation, medicinal equipment, toys, etc. Due to insufficient recycling and its non-biodegradable nature, these products end up in landfills and water bodies. Once introduced in the environment, polystyrene can undergo degradation and disintegration, mechanical abrasion and other processes that result in the formation of smaller sized microplastics that would eventually degrade into nanoplastics. Thus, these products are a significant source of polystyrene nanoplastics (PSNPs). Studies suggest that PSNPs penetrate living organisms through multiple routes via skin, respiratory and digestive tracts and consequently, their accumulation along the food chain takes place. Widespread research is going on to study the impact of polystyrene nanoplastics on different ecosystems and their species. The main focus of this review has been on the numerous sources of PSNPs, toxicity involving marine and terrestrial ecosystems and different remediation techniques such as photocatalysis, adsorption using biochar, flocculation, filtration, the electrospun membrane system and bioremediation measures that could be a possible solution to the major ecological crisis caused by PSNPs.