Tobacco-Specific Nitrosamines in the Tobacco and Mainstream Smoke of Commercial Little Cigars

Abstract

Cigars are among the broad variety of tobacco products that have not been as extensively studied and characterized as cigarettes. Small cigars wrapped in a tobacco-containing sheet, commonly referred to as little cigars, are a subcategory that are similar to conventional cigarettes with respect to dimensions, filters, and overall appearance. Tobacco-specific nitrosamines (TSNAs) are carcinogens in the tobacco used in both little cigars and cigarettes. This study uses a validated high-performance liquid chromatography–electrospray tandem mass spectrometry (LC–MS/MS) method to measure the TSNAs 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N′-nitrosonornicotine (NNN) in the tobacco filler and the nonintense International Organization for Standardization smoking regimen, ISO 3308, and the newer ISO 20778 Cigarette Intensive (CI) smoking regimen mainstream smoke of 60 commercial little cigars. Tobacco filler NNK and NNN quantities ranged from 26 to 2950 and 1440 to 12 100 ng/g tobacco, respectively. NNK and NNN by the ISO nonintense smoking regimen ranged from 89 to 879 and 200 to 1540 ng/cigar, respectively; by the CI regimen, NNK and NNN ranged from 138 to 1570 and 445 to 2780 ng/cigar, respectively. The average transfer (%) for NNK and NNN from tobacco filler to mainstream smoke was 24% and 36% by the ISO nonintense and CI smoking regimens, respectively. By the ISO nonintense and CI smoking regimens, mainstream smoke NNK and NNN yields showed a moderate to strong correlation (ISO nonintense, R 2 = 0.60–0.68, p < 0.0001; CI, R 2 = 0.78–0.81, p < 0.0001) with tobacco filler NNK and NNN quantities. In addition, the mainstream smoke NNK and NNN yields of little cigars were determined to be 3- to 5-fold higher compared to previously tested commercial cigarettes. The mainstream smoke NNK and NNN yields have wide variation among commercial little cigars and suggest that, despite design similarities to cigarettes, machine-smoke yields of carcinogenic TSNAs are higher in little cigars.

The Effect of Tobacco Smoke N-Nitrosamines, NNK and NDEA, and Nicotine, on DNA Mismatch Repair Mechanism and miRNA Markers, in Hypopharyngeal Squamous Cell Carcinoma: An In Vivo Model and Clinical Evidence

“…Based on these in vitro findings, we concluded that NNK, even at a low dose, can contribute to a dysregulated MMR mechanism and increased cell survival rates, indicating a non-dose-dependent effect of TS-related N -Nitrosamines. We have also recently shown that the combination of N -Nitrosamines, NNK and NDEA, at concentrations based on values previously measured in the mainstream of TS [ 24 , 25 , 26 ] and used in in vivo models [ 6 , 28 , 29 , 30 ], could promote pre-neoplastic lesions in in vivo exposed murine hypopharyngeal mucosa, possibly through the activation of NF- κ B and its related oncogenic pathways [ 6 ]. On the other hand, we have shown that the combination of tobacco smoke N -Nitrosamines with other risk factors, such as bile reflux, was particularly noxious, as it could accelerate the carcinogenic process by causing invasive cancer [ 6 ].…”

“…Here, we used an in vivo murine experimental approach involving a long time treatment (14 weeks) of the hypopharynx to TS-related N -Nitrosamines, NNK and NDEA, with or without nicotine, investigating for the first time whether chronic exposure to TS components can affect the MMR mechanism and miRNA markers, previously linked to carcinogenesis of the upper aerodigestive tract [ 19 , 35 , 36 , 41 ]. We used a mixture of NNK and NDEA, with or without nicotine, at concentrations based on our prior in vivo model and other studies [ 6 , 24 , 25 , 26 , 28 , 29 , 30 ]. Our novel in vivo experimental data provides direct evidence that chronic exposure of the murine hypopharyngeal epithelium to TS components can induce a defective MMR mechanism and deregulation of cancer-related regulatory miRNA molecules in premalignant murine HM, providing new insights into the mechanism of TS-related carcinogenesis of the upper aerodigestive tract ( Figure 8 ).…”

“…After acclimatization of mice (2–3 days), treatment exposure, experimental, and their corresponding control procedures were performed in parallel, as described in our approved protocol (11039, by IACUC; Yale University). According to previous studies, the concentrations of N -Nitrosamines in TS mainstream, is up to 2950 ng/cigarette for NNK, up to 28 ng/cigarette for NDEA, and 0.5 to 1.6 mg/cigarette for nicotine [ 24 , 25 , 26 ]. Therefore, it is considered that a 20 pack year smoker can be exposed to approximately 5 mg/kg NNK, 0.05 mg/kg NDEA, and 0.1–0.4 mg/kg nicotine in total [ 27 ].…”

Harmful and Potentially Harmful Constituents in the Filler and Smoke of Tobacco-Containing Tobacco Products

“…For each TCTP type and relevant matrix, each HPHC is in one of three categories: “established data”, “limited data”, and “no data”. An HPHC is categorized as having established data if (1) the literature searches had relevant results and the HPHC did not fall into the limited data category or (2) other ongoing research projects , or subsequent FDA publications from these studies , covered the analysis of this HPHC in a specific tobacco product type and matrix. An HPHC is categorized as having limited data if (1) the publications available did not include domestically available (i.e., United States) commercial TCTP, (2) the publication lacked test method information, (3) the publication methods are outdated (i.e., high detection limit compared to the recent literature), or (4) the publications report conflicting results.…”

Yield and Quality of Three Cultivars of Dark Fire-Cured (Kentucky) Tobacco (Nicotiana tabacum L.) Subjected to Organic (Compost) and Mineral Nitrogen Fertilization

“…In particular, N accumulates in fresh leaves as nitrates when plants are grown under excess N fertilization [14,16,22,28,29] which, in turn, means a potential high undesirable tobacco specific nitrosamine (TSNA) content in commercial products after the curing period [16,30,31]. TSNAs are potentially carcinogenic compounds [32,33]. Excess N fertilization also decreases the tobacco agronomic N use efficiency, and there is a negative relationship between the percentage amount of N recovered by plants and the increase in the N fertilization rate [14].…”