Regulatory toxicology and pharmacology : RTP
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Regul. Toxicol. Pharmacol. · Dec 2014
Comparative StudyComparison of select analytes in aerosol from e-cigarettes with smoke from conventional cigarettes and with ambient air.
Leading commercial electronic cigarettes were tested to determine bulk composition. The e-cigarettes and conventional cigarettes were evaluated using machine-puffing to compare nicotine delivery and relative yields of chemical constituents. The e-liquids tested were found to contain humectants, glycerin and/or propylene glycol, (⩾75% content); water (<20%); nicotine (approximately 2%); and flavor (<10%). ⋯ Analysis of the smoke from conventional cigarettes showed that the mainstream cigarette smoke delivered approximately 1500times more harmful and potentially harmful constituents (HPHCs) tested when compared to e-cigarette aerosol or to puffing room air. The deliveries of HPHCs tested for these e-cigarette products were similar to the study air blanks rather than to deliveries from conventional cigarettes; no significant contribution of cigarette smoke HPHCs from any of the compound classes tested was found for the e-cigarettes. Thus, the results of this study support previous researchers' discussion of e-cigarette products' potential for reduced exposure compared to cigarette smoke.
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Regul. Toxicol. Pharmacol. · Dec 2014
Comparative StudyToxicological assessment of kretek cigarettes Part 3: kretek and American-blended cigarettes, inhalation toxicity.
A typical Indonesian kretek cigarette brand and an experimental kretek reference cigarette were compared to the reference cigarette 2R4F in two 90-day inhalation studies. Male and female rats were exposed nose-only to mainstream smoke for 6 hours daily, for 90 consecutive days. Biological endpoints were assessed according to OECD guideline 413, with special emphasis on respiratory tract histopathology and on lung inflammation (broncho-alveolar lavage fluid levels of neutrophils, macrophages and lymphocytes). ⋯ Neutrophilic inflammation was also significantly lower (>70%). These results are consistent with the observations made on smoke chemistry and in vitro toxicology. They do not support any increased toxicity of the smoke of kretek cigarettes compared to conventional American-blended cigarettes.
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Regul. Toxicol. Pharmacol. · Dec 2014
Toxicological assessment of kretek cigarettes: Part 2: kretek and American-blended cigarettes, smoke chemistry and in vitro toxicity.
Two commercial kretek cigarettes typical for the Indonesian market and a reference kretek cigarette were compared to the American-blended reference cigarette 2R4F by smoke chemistry characterization and in vitro cytotoxicity and mutagenicity assessments. Despite the widely diverse designs and deliveries of the selected kretek cigarettes, their smoke composition and in vitro toxicity data present a consistent pattern when data were normalized to total particulate matter (TPM) deliveries. This confirms the applicability of the studies' conclusions to a wide range of kretek cigarette products. ⋯ Yields of light molecular weight pyrolytic compounds, notably aldehydes and hydrocarbons, were reduced, while yields of polycyclic aromatic hydrocarbons were unchanged and phenol yield was increased. The normalized in vitro toxicity was lowered accordingly, reflecting the yield reductions in gas-phase cytotoxic compounds and some particulate-phase mutagenic compounds. These results do not support a higher toxicity of the smoke of kretek cigarettes compared to American-blended cigarettes.
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Regul. Toxicol. Pharmacol. · Dec 2014
Toxicological assessment of kretek cigarettes: Part 1: background, assessment approach, and summary of findings.
This publication introduces a series of six other publications describing the toxicological assessment of kretek cigarettes, i.e., cigarettes characterized primarily by the use of a significant amount of cloves as an ingredient added to the tobacco. This paper presents background information on kretek cigarettes, describes the general approach of the in vitro and in vivo toxicological assessment of mainstream smoke from kretek cigarettes, presents the methodology used, and summarizes the results of the assessment program. In summary, the smoke from kretek cigarettes gives rise to the typical cigarette smoke-related effects known from American-blended cigarettes, does not reveal any novel toxicity, and exhibits an unexpected distinct attenuation of pulmonary inflammation. ⋯ When assessed in vivo, kretek cigarette smoke shows lower toxicity in the respiratory tract. When based on an equal nicotine basis, several of the toxicity endpoints in kretek cigarettes become equivalent to American-blended cigarettes. The data do not indicate an increased hazard potential of kreteks compared to American-blended cigarettes.
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Regul. Toxicol. Pharmacol. · Dec 2014
Toxicological assessment of kretek cigarettes. Part 7: the impact of ingredients added to kretek cigarettes on inhalation toxicity.
The biological activity of mainstream smoke from experimental kretek cigarettes with and without three mixes of ingredients was assessed in a 90-day rat inhalation study and in a 4-day in vivo micronucleus assay. 350 ingredients, commonly used in various combinations and in a limited number in a given brand in the manufacture of marketed kretek cigarettes, were applied at a low and a high target level to test cigarettes with a typical Indonesian blend of tobaccos and cloves. In the 90-day inhalation study, effects commonly seen in rat inhalation studies with mainstream smoke were observed. ⋯ In the 4-day micronucleus assay exposure of male rats to mainstream smoke from the test cigarettes containing any of the three mixes did not increase the proportions of micronucleated cells in peripheral blood and bone marrow over the proportion of micronucleated cells in the control group. Based on the results of these studies, it can be concluded that the addition of ingredients commonly used in the manufacture of kretek cigarettes did not change the overall in vivo toxicity profile of the mainstream smoke.