Recycled Plastics Can Disrupt Hormones and Metabolism: Study

New Delhi – A new study has raised serious concerns about recycled plastics, revealing that a single pellet of recycled polyethylene plastic can contain more than 80 different chemicals. These chemicals can leach into water and potentially interfere with hormone systems and lipid metabolism.

The research warns that while recycling is widely promoted as a solution to the global plastic pollution crisis—which threatens both environmental and human health—recycled plastics may carry hidden dangers. Plastics contain thousands of chemical additives, most of which are not disclosed, and many of them are toxic. These hazardous substances often end up in recycled products, according to scientists from the University of Gothenburg and Leipzig University.

Published in the Journal of Hazardous Materials, the study involved plastic pellets recycled from polyethylene collected from various regions worldwide. The researchers soaked the pellets in water for 48 hours, then exposed zebrafish larvae to that water for five days.

The results showed increased gene activity linked to lipid metabolism, fat cell development (adipogenesis), and hormone regulation in the larvae.

“These short exposure times already triggered biological responses, indicating the real risks posed by chemicals in plastics to living organisms,” said lead author Azora Konig Kardgar, an ecotoxicologist at the University of Gothenburg. “The observed changes suggest that these exposures can alter fish physiology and health.”

Similar effects have previously been observed in humans, with toxic plastic chemicals linked to reproductive harm, obesity, and other metabolic disorders. Some of these substances are known endocrine disruptors, which can affect fertility, child development, increase cancer risks, and contribute to conditions like diabetes.

“This is the core problem with plastic recycling,” said Professor Bethanie Carney Almroth of the University of Gothenburg, who led the project. “We rarely know exactly what chemicals are present in recycled plastic, and there's always the risk of unknown and harmful mixtures forming during the process.”

Meanwhile, global delegates are preparing to meet in Geneva this August for what could be the final round of negotiations for a Global Plastics Treaty under the United Nations Environment Programme.

With inputs from IANS