And the solution may require new methods at recycling plants, so plastics are not stored outdoors in the elements, as well as new government regulation of an unseen type of pollution.

Australia's soft plastics recycling system disintegrated when the REDcycle program collapsed in November 2022.

But the sector may be creating its own problems - mechanical plastics recycling processes have been creating and releasing microplastic pollution into the environment and Australia is lagging behind global attempts to contain it.

More regulation of the recycling industry was needed, UOW environmental engineers Professor Faisal Hai and PhD candidate Michael Staplevan wrote in a piece published in the journal Science.

Professor Hai, Head of the School of Civil, Mining, Environmental and Architectural Engineering at UOW, said exposure to the elements prior to recycling - such as being stored outdoors at a recycling plant - made the issue worse.

"Our study shows that such environmental exposure can almost double the microplastic generation during the shredding step in the recycling plant," Professor Hai said.

"The commercial process for plastic recycling may have been emitting microplastics since its first use nearly half a century ago.

"The most effective microplastics mitigation strategy is to pinpoint their sources and prevent their release.

"Because the plastics are chemically resistant they will break into smaller particles, but they will never vanish. They will continue to become smaller, and in the process, they enter our food system."

Microplastics are tiny particles of plastic material created by the breakdown of plastics into first smaller, then microscopic, pieces which remain in the environment.

They have been known to emerge from litter breaking up after being left in the environment, but the new UOW research points the finger at commercial recycling processes as a source.

Professor Hai said external storage had been identified as a cause, and Australia was "lagging globally" in establishing new regulations for the sector to prevent microplastic pollution.

"It is not uncommon for recycling facilities to store plastics in exterior storage compounds before these are processed," Professor Hai said.

"Our study shows that such environmental exposure can almost double the microplastic generation during the shredding step in the recycling plant.

"The commercial process for plastic recycling may have been emitting microplastics since its first use nearly half a century ago."

Environmental regulators needed a new focus on microplastics in wastewater to address the problem.

"Researchers and the recycling industry need to work more closely to find ways to effectively contain the microplastics that facilities emit," Professor Hai said.

"Environmental regulatory agencies should implement and enforce wastewater emission standards that specifically target microplastics as a contaminant of concern, similar to the policies the European Commission has proposed."