By Joe McCarthy
Students at the University of California at San Diego could soon be driving toward a future without plastic pollution.
That’s because the university recently approved a road made with recycled plastic waste, the first time a road of this style has been paved in the United States, according to the school’s paper UCSD Guardian.
The road comes from the UK-based company MacReber, which has paved roads throughout its home country and in Australia.
The UC San Diego test case covers only a small area in front of a graduate housing complex, but the university may introduce the plastic asphalt throughout the campus if it proves viable, especially because of its supposed environmental benefits.
Plastic-suffused asphalt reduces the amount of petroleum in asphalt and repurposes plastic waste that would otherwise contaminate environments, according to MacReber.
It’s also a cheaper alternative than traditional asphalt.
If the process becomes more widely implemented throughout the US, it could mitigate plastic pollution and help the country deal with its ailing network of roads.
“Recycled plastic binders are ‘closing the loop’ by using plastic that had been used for something else and giving it new life, keeping the plastic out of our landfills and oceans,” Sara McKinstry, campus sustainability manager, told the UCSD Guardian. “The recycled plastic product also has a lower embodied carbon footprint than traditional bitumen, preventing some greenhouse gases from being emitted and contributing to climate change.”
MacReber’s CEO Toby McCartney started the company because he saw plastic waste as both a threat to the planet and a valuable resource.
Globally, more than 420 million tons of plastic are produced annually and around 75% gets thrown away, where it ends up contaminating the global environment. The world’s oceans absorb around 13 million tons of plastic annually, which harms more than 700 marine animals including whales, krill, turtles, and coral.
MacReber’s process works by first collecting plastic waste that would otherwise go to landfills or ecosystems and sorting them according to their polymer structures. For example, plastic bottles and plastic bags have different properties.
The company then breaks the plastic into three different types of pellets that vary in durability and pliability. Asphalt producers buy the pellets that fit their needs — for example, roads with lots of heavy machinery traffic would require more durable pellets — and melt it into bitumen, which is the petroleum-based binding agent in asphalt.
McCartney said that the pellets can be incorporated seamlessly into any existing asphalt infrastructure. Since the pellets are melted and converted into bitumen, the presence of plastic disappears, according to the company.
“It’s important that our plastics all fully homogenise into the mix,” MacReber wrote in a company frequently asked questions section. “There are therefore no plastics present in the end asphalt – just a polymer modified bitumen. So no microplastics are in the end asphalt mix, and no leaching of any plastics can occur.”
Roads made from plastic waste have been criticized in the past as being misleading because of their potential to spread microplastics into the environment. Microplastics saturate the air we breathe, the water we drink, and the food we eat. In fact, the average human consumes at least 70,000 microplastics annually.
The health consequences of microplastic consumption are still unclear, according to National Geographic. But microplastics attract pollutants when in the environment, collecting agricultural pesticides, chemicals from industrial plants, greenhouse gas emissions, and more.
MacReber argues that this contamination wouldn’t happen with its roads and the amount of plastic it could conceivably convert to asphalt is staggering.
In fact, the company claims that every 10 tons of asphalt made with its uses 71,432 plastic bottles or 435,592 plastic bags.
With more than 4 million miles of road in need of repair throughout the US, MacReber could find a broad customer base in the country, especially because plastic pollution has energized a lot of US citizens who are eager to protect the planet.
“It is fantastic to see my school continue leading the way in implementing sustainable practices like this,” Sophie Haddad, UCSD California public interest research group chair, told the UCSD Guardian. “These roads address plastic pollution and help us pave a way toward a cleaner future. Students here love our beaches so much, so it’s great to see UCSD taking action to recycle plastics so they don’t end up polluting the ocean.”
