Short-term fragmentation of single-use plastic carrier bags in natural environment

Abstract

About 50% of single-use plastic carrier bags are discarded after one use. There has been a gradual increase in awareness of the accumulation of end-of-life plastics and their impact on the environment, which has led to interest in the development of degradable polymers. Cassava bioplastics (polylactic acid), oxo-biodegradable, and compostable plastics are often considered a potential solution to the accumulation of plastic waste, but it was unknown whether they can be biodegraded in the natural environment. Thus, this study aims to determine the fragmentation of single-use plastic bags under various natural conditions, which are declared to have biodegradable, oxo-biodegradable, or compostable properties. Four types of degradable plastic and conventional single-use plastic carrier bags were stored in natural conditions (open-air, river water, and soil). After one month, we conducted an analysis of plastic bags, specifically examining factors such as their visual attributes, load-bearing capacity, polymer identification, and microplastic generation. Surprisingly, the compostable plastic, which was expected to demonstrate enhanced degradation when buried in soil, remained stable, as indicated by its polymer composition. This finding suggests that there is a need to improve the criteria for biodegradable plastic carrier bags to ensure that they undergo biological degradation.