Impact of cigarette butts on bacterial community structure in soil

Cigarette butts contribute significantly to global pollution present on the planet. The filters found in cigarette butts contain a microplastic, cellulose acetate, as well as toxic metals and metalloids which are responsible for pollution in the environment. Although cigarette butt litter is prevalent in many soils, research on the effects of these cigarette butts is limited. In this study, we used Automated Ribosomal Intergenic Spacer Analysis (ARISA) to generate DNA fingerprints of bacterial communities in soil before and after the addition of cigarette butt leachate treatments. An ICP-MS analysis of the biodegradable and non-biodegradable cigarette butts revealed the presence of various elements: Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, Sr, V, and Zn. The analysis also specified which metals were present at the highest concentrations in the biodegradable and non-biodegradable cigarette butts, and these were, respectively, Al (1,31 g/kg and 2,35 g/kg), Fe (2,03 g/kg and 1,11 g/kg), and Zn (3,18 mg/kg and 15,70 mg/kg). Our results show that biodegradable cigarette butts had a significant effect on bacterial community composition (beta diversity), unlike the non-biodegradable butts. This effect can be attributed to higher concentrations of certain metals and metalloids in the leachate of biodegradable cigarette butts compared to the non-biodegradable ones. Our findings suggest that biodegradable and non-biodegradable cigarette butts can significantly affect bacterial communities in soil as a result of the leaching of significant quantities of certain elements into the surrounding soils.