The scientists turning recycled ocean plastic waste into roads

A team of researchers in Hawaii are trying out making roads from recycled ocean plastic waste.

It's the first time that ocean plastic waste has been recycled in this way, and it aims to help tackle the enormous amount of plastic waste found in the Pacific Ocean surrounding the island.

So far, as part of their research scientists have removed around 90 tons of plastic rubbish from the Pacific Ocean, and more than a metric tonne of fishing nets alone have been turned into Hawaiian roads.

The scientists are also testing the roads to see if they are durable enough, and if they shed any microplastics into the environment - and so far the results have been positive.

"By reusing plastic waste that is already in Hawaii, we can reduce the environmental and economic impacts of transporting waste plastics from the islands, incinerating it or dumping it in Hawaii's overflowing landfills," said lead researcher Jeremy Axworthy.

The team of scientists from the Center for Marine Debris Research at Hawaii Pacific University in Honolulu run a program called Nets-to-Roads.

Through this, the team of marine biologists collect and sort through ocean plastic waste made from a durable type of plastic called polyethylene, which is found in milk bottles, yoghurt pots and fishing nets.

Once collected and sorted the team then sent the waste to the US, where it was shredded and ground into tiny pieces.

From there it was returned back to Hawaii and taken to a pavement production facility, where it was mixed with other ingredients to make asphalt - the material used to make roads.

The hot mix was then loaded onto trucks and used to pave some test roads.

Around a year later the scientists ran tests on the plastic roads to check how durable they have been, and if any microplastics have been shed from them.

They did this by testing samples of soil and dust from around the plastic roads. They also tested regular roads for comparison, as well as doing a test to mimic the effects of storm water.

They found that the recycled plastic roads did not release more microplastics than the standard roads.

"Some people think plastic recycling is a hoax, that it doesn't work; it's too challenging. But this work demonstrates that recycling can work when society prioritises sustainability." said Jennifer Lynch the co-director of the Center for Marine Debris Research.