Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-4 (of 4 Records) |
Query Trace: Hearn BA[original query] |
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Multi-year Study of PAHs in Mainstream Cigarette Smoke
Hearn BA , Ding YS , Watson CH , Johnson TL , Zewdie G , Jeong-Im JH , Walters MJ , Holman MR , Rochester CG . Tob Regul Sci 2018 4 (3) 96-106 OBJECTIVES: Correlations are made between mainstream cigarette smoke deliveries of individual PAHs over multiple years. Average overall PAH deliveries in mainstream cigarette smoke by study year, mentholation, ring size, and manufacturer are compared. METHODS: Mainstream smoke deliveries were determined by GC/MS for 14 polycyclic aromatic hydrocarbons (PAHs) from selected cigarettes on the US market in 2002, 2004, 2007, and 2011. The mainstream smoke PAH emissions were measured under international standardization organization (ISO) smoking conditions. Pearson product-moment correlation was used to examine the linear relationship among the PAHs over multiple years. RESULTS: A number of the PAH analytes were statistically highly correlated with each other. The overall average for mainstream smoke deliveries of PAHs did not change significantly between study years. Similar levels in average PAH deliveries were seen for mentholated and non-mentholated cigarettes. CONCLUSIONS: The strong correlations between PAH compounds over multiple years show that a limited set of PAHs can predict deliveries of others with confidence over multiple years. A more limited panel of analytes may be considered when designing studies involving PAH measurements in mainstream smoke. |
A high throughput method for estimating mouth-level intake of mainstream cigarette smoke
Yan X , Zhang L , Hearn BA , Valentin-Blasini L , Polzin GM , Watson CH . Nicotine Tob Res 2015 17 (11) 1324-30 INTRODUCTION: We developed a high throughput method for estimating smoker's mainstream smoke intake on a per-cigarette basis by analyzing discarded cigarette butts. This new method utilizes ultraviolet/visible (UV-Vis) spectrophotometric analysis of isopropanol-soluble smoke particulate matter extracted from discarded cigarette filters. METHODS: When measured under a wide range of smoking conditions for a given brand variant, smoking machine delivery of nicotine, benzene, polycyclic aromatic hydrocarbons, and tobacco-specific nitrosamines can be related to the overall filter extract absorbance at 360nm. Once this relationship has been established, UV-Vis analysis of a discarded cigarette filter butt gives a quantitative measure of a smoker's exposure to these analytes. RESULTS: The measured mainstream smoke constituents correlated closely (correlation coefficients from 0.9303 to 0.9941) with the filter extract absorbance. These high correlations held over a wide range of smoking conditions for 2R4F research cigarettes as well as popular domestic cigarette brands sold in the United States. CONCLUSIONS: This low cost, high throughput method is suitable for high volume analyses (hundreds of samples per day) because UV-Vis spectrophotometry, rather than mass spectrometry, is used for the cigarette filter butt analysis. This method provides a stable and noninvasive means for estimating mouth-level delivery of many mainstream smoke constituents. The ability to gauge the mouth-level intake of harmful chemicals and total mainstream smoke for cigarette smokers in a natural setting on a cigarette-by-cigarette basis can provide insights on factors contributing to morbidity and mortality from cigarette smoking, as well as insights on strategies related to smoking cessation. |
Chemical analysis of Alaskan iq'mik smokeless tobacco
Hearn BA , Renner CC , Ding YS , Vaughan-Watson C , Stanfill SB , Zhang L , Polzin GM , Ashley DL , Watson CH . Nicotine Tob Res 2013 15 (7) 1283-8 INTRODUCTION: Iq'mik, a form of smokeless tobacco (ST), is traditionally used by Cup'ik and Yup'ik Eskimo people of western Alaska. Iq'mik is sometimes incorrectly considered to be a healthier alternative to smoking because its ingredients are perceived as "natural." Our chemical characterization of iq'mik shows that iq'mik is not a safe alternative to smoking or other ST use. METHODS: We measured nicotine and pH levels of tobacco and ash used to prepare iq'mik. We also characterized levels of toxins which are known to be present in ST including tobacco-specific nitrosamines (TSNAs) and polycyclic aromatic hydrocarbons (PAHs) using chromatographic separations coupled with isotope dilution mass spectrometry. RESULTS: Nicotine content in the iq'mik tobacco was very high, ranging from 35 to 43mg/g, with a mean of 39mg/g. The pH of the iq'mik tobacco-ash mixture was 11, an extremely high level compared with most ST products. High levels of PAHs were seen in the fire-cured tobacco samples with a benzo[a]pyrene level of 87ng/g. Average TSNA levels in the tobacco were 34, 2,700, and 340ng/g for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), N'-nitrosonornicotine (NNN), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), respectively. CONCLUSIONS: Iq'mik contains high levels of the more easily absorbed unionized nicotine as well as known carcinogenic TSNAs and PAHs. The perception that iq'mik is less hazardous than other tobacco products due to the use of "natural" ingredients is not warranted. This chemical characterization of iq'mik gives a better understanding of the risk of possible adverse health effects of its use. |
Semi-volatiles in mainstream smoke delivery from select charcoal-filtered cigarette brand variants
Hearn BA , Ding YS , Vaughan C , Zhang L , Polzin G , Caudill SP , Watson CH , Ashley DL . Tob Control 2010 19 (3) 223-30 BACKGROUND: It has been reported that charcoal added to cigarette filters selectively removes many of the more volatile chemicals, but it is not clear to what extent charcoal may reduce the delivery of important less volatile chemical constituents in mainstream cigarette smoke. METHODS: We analysed machine-derived mainstream smoke deliveries (under three smoking regimens) for variants of a charcoal-filtered cigarette commercially test-marketed in the USA, focusing on selected polycyclic aromatic hydrocarbons (PAHs), phenols and tobacco-specific nitrosamines (TSNAs). Results While charcoal-containing filters selectively removed lower molecular weight PAHs from mainstream smoke, they did not significantly remove the heavier and more toxic PAHs studied, such as benzo[a]pyrene, a known carcinogen. Likewise, charcoal-containing filters removed phenols and TSNAs from mainstream smoke to differing amounts depending on the compound, filter design and the smoking regimen. CONCLUSIONS: The addition of sufficient charcoal to cigarette filters is known to remove many volatile compounds and can potentially reduce deliveries of certain semi-volatile compounds under some machine smoking regimens. Less volatile compounds, with a significant portion in the particulate phase, are less available for selective filtration by charcoal-containing filters than the more volatile compounds that reside predominantly in the gas phase. |
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