A school of fish
People have been consuming tiny particles of microplastic via food and water – as well as inhaling them – with potentially hazardous effects, yet neither the concrete effect, nor the extent of the problem is known so far.Traditional plastics based on fossil fuel and oil products have flooded the earth to the point that microplastics are found in all living things, sparking intensive research to find alternatives that decompose faster in nature.One such option, touted as “climate-friendly”, are biopolymers based on cane sugar. The most common bioplastic is polylactide (PLA) used in, for example, 3D-printers, textiles, food packaging and disposable cutlery.But, according to a recent study, even bioplastics have a negative effect on wildlife. A team led by Azora Konig Kardgar of the University of Gothenburg, Sweden, has found that exposure to bioplastics in fish food for six months changed the behavior of perch. Among other things, the fish showed signs of reduced movement, an altered ability to form shoals, and a changed response to approaching danger.
"It is very rare that toxicological experiments with analysis of the animals' behavior are carried out. The usual thing is to look at the physiological changes. We see that there is something in PLA plastic that causes a change in the fish, but we cannot see what," Azora Konig Kardgar said in a press release.
Organic Farming Potentially Worse for Environment Than Conventional, Study Warns24 December 2021, 06:20 GMTThe experiment split the fish into three groups: the first were fed contaminated food containing 2 percent PLA, roughly concentration of the common petrochemical-based plastic used in previous studies; the second group was fed the same percentage of kaolin particles – a white clay used to make porcelain; and the third was a control group fed uncontaminated food.Remarkably, the fish fed organic kaolin also showed changes in behavior. Furthermore, chronic particle ingestion also affected gene expression related to oxidative stress and androgen disruption.
"We see that PLA is not harmless to the fish, so it should not be sold as an environmentally friendly alternative to ordinary plastic. It should be considered as ordinary plastic," Konig Kardgar said.
The researchers concluded that more studies should be conducted on the differences between biobased polymer microplastics and conventional polymer microplastics and their levels of toxicity.
What Is Microplastic?
Microplastics are tiny plastic particles that result from both commercial product development and breakdown of larger plastics. It is estimated that they could take hundreds or even thousands of years to break down and therefore plastic debris is accumulating in oceans and air year on year. Microplastics can be harmful to the environment as well as animal and human health.Since the discovery of plastics, huge amounts of discarded waste have been dumped in the environment – to the point that microplastics now contaminate the entire planet, from the mountain tops of the Himalayas to the deepest oceanic trenches. People have been consuming the tiny particles via food and water and inhaling them, and they have been found in the feces of both adults and babies. A 2022 study detected microplastic pollution in human blood for the first time.The particles were found to travel around the body and lodge in different organs. However, the exact effect on health and the scope of it remains unknown.