We live surrounded by plastics, especially when we go shopping at the supermarket. There we will find bottles, food containers and bags of this material everywhere. Given its excessive use, the alternative has been compostable bags, made of vegetable starch and that do not produce toxic waste, in addition to degrading biologically.
However, compostable bags do not seem as sustainable as initially thought, according to a study led by researchers from the Higher Council for Scientific Research (CSIC).
The results of this research show a high level of toxicity in compostable plastic bags, which increases with photodegradation, that is, when ultraviolet rays affect them. Although the study is preliminary, with a small number of bags, those responsible assure that these results are representative of their degradation processes.
In the study, led by scientists from the Institute of Environmental Diagnosis and Water Studies (IDAEA-CSIC) and the Institute of Agrochemistry and Food Technology (IATA-CSIC) and the Susplast platform, they analyzed the toxicity of compostable plastic bags, conventional plastic bags and other recycled plastic bags in zebrafish cells. To do this, the bags were extracted to analyze the toxic compounds that could be released into the environment.
“We were surprised that cells exposed to conventional plastic bags showed no traces of toxicity. However, we did detect it in the biodegradable ones, which decreased the viability of the cells,” explains Cinta Porte, lead author of the study and researcher at the IDAEA-CSIC.
In addition, recycled plastic bags also showed higher levels of toxicity than conventional ones, since plastic additives would also be added for reuse.
The hypothesis that the researchers use to explain these results is that manufacturers add chemical additives to make biodegradable bags that could be especially toxic."
The authors of the study, published in the Journal of Hazardous Materials, warn that this accumulation of contaminants can affect the environment and negatively impact the health of the population. “The toxicity observed can derive both from the additives used during processing and from the fragments of biodegradable plastics produced during composting,” says Amparo López Rubio, researcher at IATA-CSIC.
Following the results, the research team urges to continue investigating the toxicity detected in biodegradable bags. In addition, they insist on the need to take measures to regulate the plastic additives that are added to these bags.
