In Australia, people smoke about 18 billion cigarettes a year. Cigarette butts are the most littered items in the country, with up to 9 billion cigarettes being littered annually. Around 30 percent of the Western Australia litter stream is comprised of cigarette butts which get washed into stormwater drains and waterways. Here, they leach toxic chemicals such as cadmium, lead and zinc. Butts are also commonly mistaken for food by marine life and have been found in the stomachs of fish and other marine animals. Lastly, cigarette butts are made from non-biodegradable plastic, which can take up to 15 years to break down.
Australian researchers from Fungi Solutions, a biotechnology company and Australian charity No More Butts, may have found a sustainable solution for tackling cigarette butt litter. They have teamed up to start CigCycle, a research project to determine whether Australian fungi can be used to create a viable recycling stream from cigarette butts. The researchers are training oyster mushrooms to consume cigarette butts, a process that they said resembles teaching a baby how to eat.
Oyster mushrooms put out a thin white fiber called mycelium, which covers a cigarette butt and breaks it down while drawing nutrients from it. The mushrooms will slowly recognize a food called cellulose acetate in the filter of the cigarette butt and begin to eat it. The mushrooms will use cellulose acetate in the cigarette butts as a source of nutrition and could consume most of the butts within a week. The mushrooms would be able to digest the harmful materials found in cigarette butts and leave behind materials that could be reused for other purposes. This process also breaks down the plastics used to make the filters more durable. The researchers are looking to see if the remaining materials not consumed by the mushroom could be recycled into an alternative material for polystyrene and if these materials could be used as insulation in construction and transportation.
Fungal biotechnology isn’t anything new. We’ve seen mushrooms being used to develop leather-like textiles and alternative proteins. Mushrooms have been used to clean up toxins from shredded waste materials and use biomaterials for commercial and industrial use. Fungi are known to synthesize complex hydrocarbons and toxic chemicals through their enzymes.
Fungi Solutions and No More Butts are working with the city of Melbourne to collect cigarette butts and, instead of sending them to the landfill, send them to the lab to help further their research. The project is still under trial and is expected to take two years. If proven successful, this will be a huge turning point for cigarette butt littering and might inspire other cities around the world to take action and turn waste into something reusable.