Microplastic Pollution Across Living Systems: Toxicological Effects, Knowledge Gaps, and Sustainable Remediation Strategies

Microplastics (MPs) have emerged as pervasive pollutant, now detected across the globe, including in remote and isolated ecosystems. With rising MP contamination, concerns over their impacts on living systems have intensified. While numerous studies report adverse effects of MPs, comprehensive analytical insights into their toxicity across diverse organisms remain limited. This review systematically evaluates toxicological effects of MPs on aquatic organisms, humans, plants, terrestrial organisms and microorganisms at the morphological, histological, and molecular levels. Data analysis has revealed that polystyrene is most commonly used MP for toxicity studies. It is observed that nanoplastics (NPs) remain significantly underexplored, despite evidence suggesting their higher toxic potential due to their smaller size and greater surface reactivity. Existing studies predominantly assess toxicity within concentration range of 0.1–50,000 mg/L and are limited to maximum exposure duration of 84 days, underscoring lack of long-term and chronic exposure investigations. Given that MPs persist in environmental matrices over extended periods, organisms are more likely to experience prolonged exposure. Therefore, short-term experimental studies may not adequately capture the actual ecological and biological impacts of MPs, potentially underestimating their long-term toxicity and environmental risk. In addition to synthesizing toxicity data, this review discusses existing physical, chemical, and biological remediation strategies, with emphasis on emerging sustainable technologies for real-time applications. Further, cost–benefit perspective is also provided, underscoring that timely implementation of MP removal technologies significantly outweighs the health risks associated with continued exposure. Overall, this review identifies key knowledge gaps and outlines future directions toward mitigating the risks posed by MP pollution.