Researchers from University of Gothenburg and Leipzig have unveiled alarming data showing that recycled polyethylene plastics can release chemicals detrimental to hormone systems and metabolism.
New research from the University of Gothenburg and Leipzig has revealed concerning insights into the potential dangers posed by recycled plastics. The study, published in the Journal of Hazardous Materials, indicates that chemicals leaching from recycled polyethylene plastics can significantly disrupt hormone systems and lipid metabolism, as observed in zebrafish larvae experiments.
The plastic pollution crisis is a growing global concern, placing severe pressure on environmental and human health.
While recycling is often proposed as a solution, the study highlights a critical flaw: the presence of numerous undisclosed and potentially toxic chemicals in recycled plastics. This renders the safety and sustainability of plastic recycling questionable.
In the study, the researchers acquired plastic pellets recycled from polyethylene, sourced from various parts of the world.
These pellets were soaked in water for 48 hours, after which zebrafish larvae were exposed to the water for five days. The results were strikingly concerning.
“These short leaching times and exposure times are yet another indicator of the risks that chemicals in plastics pose to living organisms,” lead author Azora König Kardgar, a researcher in ecotoxicology at the University of Gothenburg, said in a news release. “The impacts that we measured show that these exposures have the potential to change the physiology and health of the fish.”
Previous research has pointed out similar effects in humans, including threats to reproductive health, links to certain cancers, and metabolic disorders such as obesity and diabetes, due to toxic chemicals found in plastics. These substances can disturb hormonal functions leading to severe health outcomes.
“This is the main obstacle with the idea of recycling plastic. We never have full knowledge of what chemicals will end up in an item made of recycled plastic. And there is also a significant risk of chemical mixing events occurring, which render the recycled plastic toxic,” added principal investigator Bethanie Carney Almroth, a professor at the University of Gothenburg.
In addition to observing the impacts on zebrafish larvae, the research team also conducted a chemical analysis of the water-leached compounds.
They identified a variety of chemicals, some widely used in plastics, such as UV stabilizers and plasticizers, and others not typically associated with plastics, including pesticides, pharmaceuticals and biocides.
“These may have contaminated the plastics during their first use phase, prior to becoming waste and being recycled,” added Eric Carmona, a researcher in the Department of Exposure Science at the Helmholtz Centre for Environmental Research in Leipzig. “This is further evidence of the complicated issue of plastics waste flows, and of toxic chemicals contaminating recycled plastics.”
The findings arrive as global leaders prepare for the final negotiations of the Global Plastics Treaty in Geneva, scheduled for August.
The study’s authors stress the necessity for negotiators to implement strict regulations to ban or reduce hazardous chemicals in plastics, and to increase transparency and reporting within the plastics value chain.
“We cannot safely produce and use recycled plastics if we cannot trace chemicals throughout production, use, and waste phases,” Almroth added.
Source: University of Gothenburg