Plastic vs bioplastic: how long do they persist in the environment?
Plastic, as useful as it is harmful, is perhaps the most evident expression of the climatic problems related to the sphere of consumption. Bioplastic
Its versatility has made this material an indispensable element of our daily life but at the same time it is contributing in an important way to the degradation of the environment; especially when dispersed in the environment. In fact, its degradation process can last from 20 to 450 years!
In response to the numerous consequences for the environment, some alternatives to this material have been developed, including bioplastics. But are we sure that quesat is the right answer?
The persistence of bioplastic in the environment
According to a recent study, if dispersed in the environment, even bioplastics have very long degradation times, comparable to those of non-bio plastic materials. This is demonstrated by the results of an innovative experiment conducted jointly by the National Research Council involving several Italian scientific institutes.
The study, published in Polymers, looked at the long-term behavior of different types of virgin plastic granules used to make everyday objects.
Two polymers most used in plastic objects (HDPE and PP) and two biodegradable plastic polymers (PLA and PBAT) were compared; verifying the degree of aging and degradation respectively in sea water and sand. In both environments, over six months of observation, neither traditional nor bio polymers showed significant degradation.
The observation of the samples, together with the outcome of chemical, spectroscopic and thermal analyses, shows that in the natural environment bioplastics have much longer degradation times than those that occur in industrial composting conditions.
The experiment, to date the first of its kind carried out entirely in situ, used for the experimental set up the multiparametric environmental monitoring platform “Stazione Costiera del Lab Mare” located 10 meters deep in the Bay of Santa Teresa in the Gulf of La Spezia, carried out as part of the Laboratorio Mare project of the Ligurian District for marine technologies.
Anyway, the experiment is still ongoing and will end in 2023.
Bioplastics: awareness of environmental risks
“Given the very high diffusion of these materials, it is important to be aware of the environmental risks that the use of bioplastic poses, if dispersed or not properly conferred for disposal. It is necessary to inform correctly”, explains the researcher Silvia Merlino of the Cnr-Ismar of Lerici (La Spezia), coordinator of the project.
“This study highlights the importance of correct information about biodegradable plastics; especially after the stop to disposable plastic in force in Italy from January 2021 in implementation of the European directive ‘Single use plastic’; which has led to the progressive marketing of single-use biodegradable plastic products, such as the polymers examined”; adds Marina Locritani, INGV researcher and co-coordinator of the study.
