Littered cigarette filters shown to have toxic effect on aquatic life

Researchers from the University of Gothenburg have called for the filters - one of the most common forms of litter - to be completely banned.

“The filter is full of thousands of toxic chemicals and microplastic fibres, so it’s not just any piece of plastic that’s being discarded into the environment. It’s hazardous waste,” says Bethanie Carney Almroth, professor of ecotoxicology at the University of Gothenburg.

The researchers tested the effects of the toxins that are found in the filter after smoking, as well as the substances that are in the filter from the start, on aquatic mosquito larvae. It turns out that the toxins lead to a 20 per cent higher mortality rate among mosquito larvae.

Previous research has shown that the toxins in the filters also have adverse effects on many other aquatic organisms. For example, fish can die if they are exposed to concentrations corresponding to the toxins exuded by barely two cigarette butts in one litre of water for four days.

“Cigarette filters are also a major source of the microplastics that find their way into our environment – something we know has a major negative impact on biological life. The EU has already classified cigarette filters as hazardous waste,” said professor Carney Almroth.

The researchers also observed in the study how smokers in Gothenburg behave when it’s time to put out their cigarettes. It turns out that many people throw their cigarette butts on the ground even if there are ashtrays nearby.

Almroth also described the filters as “just a marketing ploy” that do little to protect the smoker’s health, as many people believe they do.

“That’s why they have to be taken off the market entirely,” she added. “It’s not the right approach to focus on making tobacco producers pay for cleaning up the filters. The problem should be prevented in the first place, rather than cleaned up later.”

In 2020, researchers began incorporating cigarette butts into bricks used for construction as they helped to lower the energy cost of firing and acted as a form of disposal for the waste.