Simulated experimental investigation of microplastic weathering in marine environment

Abstract Microplastics act as a potential vector for a wide range of contaminants, which have emerged as a major environmental hazard in the modern world. Considering the seriousness of the problem, a simulated laboratory and field experiment were conducted to study the weathering of pristine microplastics following long-term exposure to natural background radiation and the marine environment after being disposed of in the open environment. For the study, polyethylene-originating (HDPE and LDPE) microplastics were chosen. The study revealed that radiation exposure causes surface roughness and cracks, leading to an increased surface area, which can invite a wide spectrum of pollutants to sorb on their surface. Furthermore, we report that the radiation-induced morphological changes favor microbial colonization on the microplastic surface when exposed to the marine environment. The growth of biofilms on the surface of microplastics reduces their hydrophobicity, which may attract a wide variety of polar contaminants. The study led to an interesting finding: that the HDPE microplastic surface is more conducive for biofilm growth in comparison to the LDPE surface.