Soon the footpaths we walk on could be full of cigarette butts, thanks to a Melbourne scientist who also invented the stub-filled house brick.
Dr Abbas Mohajerani, a senior lecturer in RMIT's School of Engineering, has been researching inventive ways to recycle the trillions of butts produced worldwide every year.
In 2016 Dr Mohajerani demonstrated that bricks with as little as one per cent cigarette butt content can cut production costs and save the environment.
Now he's back with an even bigger plan - to put the pesky litter items in footpaths.
His team demonstrated that asphalt mixed with cigarette butts can handle heavy traffic and also improve heat conductivity.
"In this research, we encapsulated the cigarette butts with bitumen and paraffin wax to lock in the chemicals and prevent any leaching from the asphalt concrete," Dr Mohajerani said on Monday.
"This research shows that you can create a new construction material while ridding the environment of a huge waste problem."
As butts have poor biodegradability, it can take many years for them to break down, while heavy metals such as arsenic, chromium, nickel and cadmium trapped in the filters leach into soil and waterways.
The world produces around 1.2 million tonnes of butt waste each year and the quantity is expected to increase by more than 50 per cent by 2025, mainly due to a growing population, said the research published on Monday in journal Construction and Building Materials.