A recent study has found that even after being exposed to the natural environment for a period of three years, some plastic bags that were supposed to be bio degradable were intact and in a condition of being still used for shopping.
The study was conducted on compostable bags – two forms of biodegradable bag and conventional carrier bags, after they had been left exposed for a long time to the sea, air and earth. None of the weather elements were found to have been completely decomposed.
The study found that compared to the so-called biodegradable bag, the compostable bag was apparently decomposed much better to the elements. After three months in the marine environment, the compostable bag sample had completely disappeared. However the researcher said that there is need for more research to examine the products that the breakdown leads to and the possible environmental consequences of such products.
The study found that it was able to carry on shopping with the “biodegradable” bags that had been buried in the soil and the sea even after three years. On the other hand, 27 months after being buried in soil, the compostable bag was still present. Those bags were however not good enough to be used for shopping after that period of exposure.
The research, which was conducted by the University of Plymouth’s International Marine Litter Research Unit, and published in the journal Environmental Science and Technology, also raised questions about the reliability of the claims made in favour of the biodegradable formulations of such bags and whether those formulas offer adequate rates of degradation. This therefore also raises the question of the presence of a realistic solution to the issue of plastic litter.
“After three years, I was really amazed that any of the bags could still hold a load of shopping. For biodegradable bags to be able to do that was the most surprising. When you see something labelled in that way, I think you automatically assume it will degrade more quickly than conventional bags. But, after three years at least, our research shows that might not be the case,” said Imogen Napper, who led the study.
According to estimates, users discard almost half of plastic after a single use and a large part of that ends up in litter.
The study also claimed that the EU market was placed with about 98.6bn plastic carrier bags and every years since, about 100bn additional plastic bags were inserted in the market annually on the average.
The researchers also noted that statements indicating they can be “recycled back into nature much more quickly than ordinary plastic” or “plant-based alternatives to plastic” were used alongside some of these plastic products.
However the research showed that it was not possible to rely on any of the bags included in the study to show any significant or adequate degradation over a three-year period in all environments, Napper said. “It is therefore not clear that the oxo-biodegradable or biodegradable formulations provide sufficiently advanced rates of deterioration to be advantageous in the context of reducing marine litter, compared to conventional bags,” the research found.
(Adapted from TheGuardian.com)