Microplastics: a review of their impacts on different life forms and their removal methods

The pollution of microplastics (MPs) is a worldwide major concern, as they have become a major part of our food chain. MPs enter our ecosystem via different pathways, including anthropogenic activities and improper disposal of plastics. The aim of this article is to review the current scientific literature related to MPs and how they affect different life forms on earth. Briefly, MPs induced negative effects on humans are primarily linked with the oxidative stress and disruption in immunity. MPs not only affect the soil chemical and physical properties such as reduction in soil health and productivity but also impose harmful effects on soil microorganisms. Moreover, MP-induced plant growth reduction results from three complementary mechanisms: (i) reduction in root and shoot growth, (ii) reduction in photosynthesis accompanied by higher reactive oxygen species (ROS) production, and (iii) reduction in nutrient uptake via altered root growth. Given the negative effects of MPs on different life forms, it is important to remove or remediate them. We have discussed different MP removal methods including coagulation, membrane filtration technology, biochar, and biological degradation of MPs in soil and wastewater effluents. The use of ozone as ultrafiltration technique has also been shown as the most promising technique for MP removal. Finally, some future research recommendations are also put forward at the end to further enhance our understanding of the MPs induced negative effects on different life forms.

Automated summary

The pollution of microplastics (MPs) is a global concern as they are now a significant part of the food chain. This article reviews the current scientific literature on MPs and their impact on various life forms. Negative effects of MPs on humans are primarily attributed to oxidative stress and immune disruption. MPs not only affect the soil's chemical and physical properties, leading to reduced soil health and productivity, but also harm soil microorganisms. MP-induced plant growth reduction occurs through three mechanisms: reduced root and shoot growth, decreased photosynthesis accompanied by increased reactive oxygen species production, and compromised nutrient uptake due to altered root growth. In order to mitigate these negative effects, different MP removal methods are discussed, including coagulation, membrane filtration, biochar, and biological degradation in soil and wastewater effluents. The use of ozone as an ultrafiltration technique shows promise for MP removal. The article concludes with recommendations for future research to further understand the negative effects of MPs on various life forms.