Effect of microplastics in water and aquatic systems

Surging dismissal of plastics into water resources results in the splintered debris generating microscopic particles called microplastics. The reduced size of microplastic makes it easier for intake by aquatic organisms resulting in amassing of noxious wastes, thereby disturbing their physiological functions. Microplastics are abundantly available and exhibit high propensity for interrelating with the ecosystem thereby disrupting the biogenic flora and fauna. About 71% of the earth surface is occupied by oceans, which holds 97% of the earth's water. The remaining 3% is present as water in ponds, streams, glaciers, ice caps, and as water vapor in the atmosphere. Microplastics can accumulate harmful pollutants from the surroundings thereby acting as transport vectors; and simultaneously can leach out chemicals (additives). Plastics in marine undergo splintering and shriveling to form micro/nanoparticles owing to the mechanical and photochemical processes accelerated by waves and sunlight, respectively. Microplastics differ in color and density, considering the type of polymers, and are generally classified according to their origins, i.e., primary and secondary. About 54.5% of microplastics floating in the ocean are polyethylene, and 16.5% are polypropylene, and the rest includes polyvinyl chloride, polystyrene, polyester, and polyamides. Polyethylene and polypropylene due to its lower density in comparison with marine water floats and affect the oceanic surfaces while materials having higher density sink affecting seafloor. The effects of plastic debris in the water and aquatic systems from various literature and on how COVID-19 has become a reason for microplastic pollution are reviewed in this paper.