Cigarette butts are routinely the most commonly found littered object during beach cleanups, probably due to their perceived harmlessness, small size, and less pleasant alternatives for disposal. However, given their large quantities in ecosystems, they are not as harmless as we would like to think.
Tobacco contains many different chemicals that are aerosolized when burned and in the past, have been completely inhaled. Some of these chemicals include nicotine, polynuclear aromatic hydrocarbons, N-nitrosamine, natural radionuclides, arsenic, and heavy metals like Lead, Cadmium, Chromium, Zinc, Copper, and Nickel. These chemicals are found along every step of cigarette production, from the tobacco leaves absorbing chemicals from soils to the chemicals used to cure and process the tobacco.
Since the invention of the cigarette filter, some of those chemicals get partially caught in the filter and then flicked onto streets, where they wash into sewers and rivers. The filters are commonly made of cellulose acetate, an artificial fiber, sometimes with activated carbon added. The amounts of chemicals per discarded butt are very low, but when accounting for all cigarettes littered, becomes hazardous. When the filters in cigarette butts are tossed into the environment, the chemicals contained within them can leach into the soil and water. Acidic water causes more leaching of the chemicals and makes them more biologically available to plants and animals.
These chemicals are not only bad for humans when we inhale them but are also toxic to animals in the wild. Nicotine is such a powerful poison for invertebrates that it can be used as an insecticide. Some animals accumulate the chemicals in their bodies and can pass them up the food chain. Bio-accumulation is one way that humans encounter heavy metals like mercury in high concentrations, usually through fish flesh. Having point sources like cigarettes in water increases the likelihood that animals will be impacted.
To reduce the damage done by cigarette butts in our environment, we must approach the problem from multiple angles. Policy alone has proven ineffective, it must be enforced. Social pressure could take the place of active enforcement, given enough education and awareness of policies and damages. We must dispose of all of our waste responsibly.