Cigarette butts to estimate the illicit cigarette consumption proportion in a major Brazilian city.

Background: Illicit cigarette consumption (ICC) results in cheaper cigarettes and lost tax revenue. Although several methods estimate the ICC proportion, the one based on cigarette butt (CB), the most littered item worldwide, is less common. This study aimed at estimating the ICC proportion of Guarujá, a major Brazilian city, based on littered CBs.

Methods: CBs were collected along 23,694 m of highly urbanized walkways between March and April 2023. CBs licit status was assessed based on the littered brands presence in the list of approved brands in the national market by the Brazilian Health Regulatory Agency.

Findings: Of the 4231 collected CBs, 3521 had identifiable brand markings (81.5 %). In total, 26 brands were identified from seven companies. The ICC percentage ranged between 21.7 and 36.6 %, because three brands (14.9 %) are available as licit and illicit, which cannot be determined solely by examining the CBs.

Conclusion: Utilizing CBs to estimate the ICC proportion provides additional insights into understanding the illicit market and helps with the implementation of the Protocol to Eliminate Illicit Trade in Tobacco locally. Moreover, quantifying the discarded CBs levels constitutes a pivotal step for integrative evaluations of environmental repercussions, such as the reverse logistics.