Plastic waste and microplastics (MPs) formation: Management, migration, and environmental impact

Abstract

Plastics are one of the essential human needs and their production expanded from 2.00 million tons (Mt) in 1950 to 459.75 Mt in 2019. However, its manufacture inevitably generates large amounts of plastic waste, which is harmful to the environment and human health. In this review, the history of plastic development since the 1860s along with its production globally is summarized. Classification of plastics based on polymer types, production process, shape, sizes, and applications are reported. Strategies (including mechanical recycling, incineration, landfill, biodegradation, and pyrolysis) to manage plastic waste are stated. Environmental factors that break down plastic waste into microplastics (MPs) (<5mm) and cause pollution to the entire ecosystem are deeply discussed. The studies on the effects of MPs on animals and human beings are tabulated. Polyethylene terephthalate and polyethylene were found to be the most frequently used plastics with longer degradation periods (>10 years), which could contribute to MPs abundance. Physical, chemical, and biological actions were the main environmental factors that converted plastic waste to secondary MPs. MPs not only directly affect the growth and reproduction of aquatic and terrestrial animals, but also cause harm to the human lungs, kidneys, liver, blood, and cardiovascular systems. Hence, more researches are still required to fill the knowledge gaps on the influence of MPs in the ecosystem and develop potential approaches for the removal of MPs from all environments.