Cigarette Butts - a Major Source of (Micro)plastics

In about 1970 a survey was made in Finland about the different types of trash in the environment, and I made a similar survey on the roadsides and beaches of South Wales. The most common type of trash was cigarette butts. At least 80 % of smokers have thrown smoked cigarette butts to the environment. They may not be as visible as larger trash, but as already the early surveys indicate, easily found, and in beaches a significant nuisance just as trash.

However, cigarette butts are not just a nuisance. Cigarette filters are plastic. Apart from tyre wear particles they are probably the most important source of aquatic microplastics. The problem with plastics from  cigarette filters is that they have high concentrations of all the toxins that cigarettes have. Since the toxins, e.g. the ones causing lung cancer in humans, are lipophilic, they adsorb to the plastics in the filters, and even when the filter is broken up to microplastics remain attached to the plastics. This means that whenever animals eat plastic particles, they will get much toxic compound, which are easily absorbed in the intestine, where lipophilic compounds easily cross intestinal epithelium. This “Trojan horse”-type behaviour makes the cigarette butt-derived microplastics much worse pollutants than any other plastics even if other plastic particles can also have smaller amounts of adsorbed harmful substances.

Pictures of ingested cigarette butts in fish intestine have been circulated. However, small microplastic particles are ingested by planktonic organisms such as early life stages of fish and water fleas. It has been shown that fish development is disturbed by cigarette butts, and indicative of the harmful toxins being involved, the developmental disturbances are more severe for smoked cigarette butts than for unsmoked ones (Lee & Lee 2015. Ecotoxicology and Environmental Safety 113, 362-368). With regard to zooplankton such as daphnia, they ingest microplastics, and ingestion of microplastic particles can cause at least experimentally induced population decreases (Bosker et al. 2019. Environmental Pollution 250, 669-675).

So tobacco smoking affects also environment and people, who are not in any contact with smoke. In the plastic pollution, it is an important component, I would say a major one in Europe and North America. Furthermore, it could be completely finished: stop smoking or if you cannot do that, do not throw your cigarette butts in environment.