The cigarette butts littering the street could soon have a new life within those very streets, thanks to research out of RMIT University.

Dr Abbas Mohajerani has been working for years on dealing with the problem waste stream of cigarette butts, whose toxic chemicals can leach into waterways.

A year ago we wrote about his work to use cigarettes to build cheaper and cleaner bricks.

Now his team’s back with a new solution to the scourge, encapsulating them and mixing them with asphalt to produce road materials that not only can handle traffic, but which can contribute to reducing the urban heat island effect by reducing thermal conductivity.

“I have been trying for many years to find sustainable and practical methods for solving the problem of cigarette butt pollution,” Dr Mohajerani said.

In the latest research, cigarette butts were encapsulated with bitumen or paraffin wax to prevent leaching, and then mixed with hot asphalt. The research showed that the material encapsulated with bitumen not only met the requirements of heavy traffic, but reduced bulk and increased porosity, lowering thermal conductivity – meaning cooler streets.

“Encapsulated cigarette butts developed in this research will be a new construction material which can be used in different applications and lightweight composite products,” Dr Mohajerani said.

“This research shows that you can create a new construction material while ridding the environment of a huge waste problem.”

It is estimated about six trillion cigarette filters are produced every year, leading to 1.2 million tonnes of waste globally. This figure is expected to grow by 50 per cent by 2025 as the world’s population grows.

The research, Physico-mechanical properties of asphalt concrete incorporated with encapsulated cigarette butts, has been published in Construction and Building Materials.