New biodegradable materials could be the answer to plastic pollution

As plastic pollution continues to be a global problem affecting both human and environmental health, scientists have developed new biodegradable materials which could help to rectify this.

Plastic is now so widespread it has been found at the bottom of the deepest oceans and near Everest’s peak, while microplastics have even been found in our blood.

Hoping to solve this issue, scientists at the University of California San Diego have developed materials which have been proven to biodegrade in compost and seawater by a study published in Science of the Total Environment. 

Working alongside the Scripps Institution of Oceanography, the team found their polyurethane foam, developed over the last eight years, was colonised by marine microorganisms and biodegraded back to the starting chemicals.

These microorganisms, which were mainly bacteria and fungi found in natural marine environments, then consumed these chemicals as nutrients.

‘Improper disposal of plastic in the ocean breaks down into microplastics and has become an enormous environmental problem,’ said Stephen Mayfield, professor in UC’s School of Biological Sciences and director of the California Center for Algae Biotechnology. ‘We’ve shown that it’s absolutely possible to make high performance plastic products that also can degrade in the ocean. Plastics should not be going into the ocean in the first place, but if they do, this material becomes food for microorganisms and not plastic trash and microplastics that harm aquatic life.’

The researchers used the Ellen Browning Scripps Memorial Pier and Experimental Aquarium which allowed them to test the materials in a natural near ecosystem, exactly like the environments plastics tend to end up in.

They also exposed foam samples of the material to tidal and wave dynamics, tracking molecular and physical changes, and found that it started degrade in as little as four weeks.

Microorganisms found in six marine sites around San Diego were also discovered to be capable of breaking down and consuming the polyurethane material.

‘No single discipline can address these universal environmental problems but we’ve developed an integrated solution that works on land—and now we know also biodegrades in the ocean,’ said Mayfield. ‘I was surprised to see just how many organisms colonize on these foams in the ocean. It becomes something like a microbial reef.’

It’s hoped this could go some way to helping to tackle the global plastic crisis, as researchers estimate that eight billion kilograms of plastic enter the ocean each year, collecting in locations such as the Great Pacific Garbage Patch.

In the UK, the Big Plastic Count found Brits collected 1.8 billion pieces of plastic within a week, leading organisers to call for an end to single-use plastics.

Photo by Daniel Zhen, Algenesis Inc.