The aging behaviors and release of microplastics: A review

Microplastics (MPs) have attracted significant concern due to their persistence and adverse effects on organisms. In this review, we summarize the recent literature on the natural and artificial aging process of MPs, and also discuss the associated aging characteristics and mechanisms of MPs. The aged MPs show different morphological and chemical properties from the pristine MPs. Furthermore, to evaluate associated aging effects, the corresponding release of aging process of MPs were systematically evaluated, including the additives and intermediates. Different types of organic pollutants and heavy metals additives are listed. In addition, the release of MPs is affected by environmental factors (i.e., Illumination, salinity, temperature and pH). Aged MPs are more easily absorbed by organisms and have different toxic effects from the pristine MPs. The potential risks of aging MPs and the release of MPs during aging are discussed in detail. This overview provides a direction for further study on the behavior and the toxic effects of MPs in the environment.