Cigarette butts are toxic to fish and should be labeled as toxic hazardous waste, US researchers say.
According to a report on the Canadian news service CBC, scientists at San Diego State University say that a single cigarette butt containing a small amount of unburnt tobacco is enough to contaminate a litre of water and kill half of the fish swimming in it. As a result, the scientists say cigarettes should be considered toxic waste and new requirements established for how they are disposed.
Cigarette butts were left soaking in water for a day before fish were placed in it for testing. Whole cigarettes and cigarette butts with unburnt tobacco were found to be the most toxic, but even filters that had been smoked and that had no tobacco left on them were found to be toxic. Cigarette filters are made of cellulose-acetate, which does not biodegrade.
According to the report, cigarette butts are considered the most littered item in the world. It was recently estimated that 767 million kilograms of cigarette butts or about 4.5 trillion butts end up as litter every year.