There has been limited toxicity testing of cigarillos, including comparison to cigarettes. The present study compared the smoke chemistry and the cytotoxic and genotoxic potential of ten conventional cigarettes and ten cigarillos based on the greatest market share. Whole smoke and total particulate matter (TPM) were generated using the Canadian Intense (CI) and International Organization for Standardization (ISO) puffing protocols. Tobacco specific nitrosamines (TSNAs), carbonyls, and polycyclic aromatic hydrocarbons (PAHs) were measured using GC-MS. TPM smoke extracts were used for the in vitro assays. Cytotoxicity was assessed in HBEC4 cells using the neutral red uptake assay. Genotoxic potential was assessed using the micronucleus (MN; A549 cells), Ames, and thymidine kinase (TK) assays. TPM from all cigarillos tested was more cytotoxic than cigarettes. MN formation was significantly greater for cigarillos compared to cigarettes at the highest dose of TPM, with or without rat liver S9 fraction. In the Ames test +S9, both tobacco products exhibited significant dose-dependent increases in mutation frequency (MF), indicating metabolic activation is required for genotoxicity. In the TK assay +S9, cigarillos showed a significantly enhanced MF although both tobacco products were positive. The levels of all measured PAHs, TSNAs, and carbonyls (except acrolein) were significantly greater in cigarillos than cigarettes. The CI puffing protocol demonstrated increased smoke constituent levels compared to ISO.  Even though the gas vapor phase was not tested, the results of this study showed that under the tested conditions the investigated cigarillos showed greater toxicity than comparator cigarettes.

These data are from particulates (total particulate matter, TPM) collected from cigarette and cigarillo smoke generated using a smoking machine with ISO and CI smoking regimens. 10 cigarette brands and 10 cigarillo brands were investigated.

Cytotoxicity was performed by the Neutral Red Cytotoxicity Assay (NRU, using human bronchial epithelial HBEC4 cells, Repetto et al., 2008).

Genotoxicity was carried out using the Ames Modified ISO kit Assay (using TA98 and TA100 bacterial strains, https://www.ebpi-kits.com), the Micronucleus Assay (Bryce et al., 2007) using Lung A549 cells, and the Thymidine Kinase Assay (L5178Y TK+/- cells), +/-S9 .

See the publication in Tox Sciences for further details on the methods.