- Dettagli della rivista
- Pubblicato per la prima volta
- 01 Jan 1992
- Periodo di pubblicazione
- 4 volte all'anno
- Accesso libero
Pagine: 337 - 337
- Accesso libero
Pagine: 338 - 358
Particulates, especially those in the respirable fraction, are generally suspected of being responsible for a host of respiratory and cardiovascular health problems that may include an increase in morbidity and mortality. These effects have been related not only to the carbonaceous particulates, such as diesel soot, but also to more inert dust particles without any specific intrinsic hazard.
Therefore, any exposure to respirable dust from consumer products, and especially from tobacco products, is of considerable concern. In this context, a report of particular interest to the general public purported to show that cellulose acetate fibres released from cigarette filters could represent an additional burden and risk to the smoker. The underlying presumption was that these fibres could be respired and retained in portions of the respiratory tract, in particular in the lung.
In response to these assertions, studies were performed by and on behalf of the affected industry and the results showed that these fibres did not pose a health risk. The findings revealed that some acetate fibres were generated during the processing of the cigarettes, but they were captured on the cross-section of the cigarette filter and remained on the filter during smoking. Those fibres potentially released during smoking would be deposited inside the mouth area because they were too large to pass the larynx and could not physically enter the bronchial or pulmonary sections of the respiratory tract.
A working group from the German StandardisationOrganisation (DIN) recently discussed the experimental findings regarding the fibres generated during the processing of the acetate cigarette filter. Additional examinations on the release of respirable particles were initiated using Scanning Electron Microscope (SEM) to focus special attention on fibre-shaped particulates. The results of these recent analyses and the former findings led the group to the conclusion that ‘from the toxicological perspective, compared to the health risks otherwise associated with cigarette smoking, the release of particles from acetate filters does not constitute a particular health risk’.
Subsequent to this review and evaluation of the results some additional examinations were performed to examine further aspects of particle release. Using an improved analytical technique with real-time detection, the particle number and sizes were determined for the release of respirable particles from cigarettes and cigarette filters. The studies were performed by drawing air through filters and filter cigarettes in a clean room under intense smoking conditions, and the particles were analysed in real time with a Laser Aerosol Spectrometer. Using this technique, approximately 10 particles with a size greater than 0.3 ìm were counted per cigarette. This is comparable to a particle load in a clean room environment and representing approx. 0.05% of the particle load in ambient air.
- Accesso libero
Pagine: 359 - 367
A study using atomic emission detection (AED) as an approach to explore the fate of quinone added into 2R4F cigarette smoke condensate (CSC) have been performed. Both natural isotope quinone and 13C labeled quinone were used in the study. When coupled with a gas chromatographic separation (GC/AED), the AED provided informative new data on 13C isotope enriched products generated following reactions between 2R4F CSC and the quinone. Two 13C containing species were detected by GC/AED. Matching chromatographic separation using gas chromatography/mass selective detection (GC/MSD) allowed for a structural assignment of a relatively minor CSC 13C 6quinone reaction product as nitrohydroquinone (13C6NO2HQ). The chemical mechanism accounting for the formation of 13C6NO2HQ in the CSC was envisioned to be a reaction product between HONO and 13C 6Quinone (13C6Q) to form 13C6NO2Q, followed by reduction of 13C6NO2Q to 13C6NO2HQ. The amount of 13C6NO2HQ accounted for ~6% of the added 13C6Q. Identical trends in reaction chemistries were found for experiments with 12C6Q. The major reaction product detected upon addition of 13C6Q to the 2R4F CSC sample was 13C6HQ. 13C6HQ accounted for, on average, ~47% of the initial 13C6Q concentration. Identical trends in reaction chemistries were found for experiments with 12C6Q. No additional 13C containing species were detected. A 13C AED compound independent calibration (CIC) approach under the operating conditions was not possible. This work further expands the knowledge regarding possible reactions of quinone and hydroquinone in CSC.
- Accesso libero
Monitoring the Bacterial and Fungal Biota of Eleven Tobacco Grades Stored at Three Different Locations
Pagine: 368 - 376
Tobacco as many other plants has its own microbiota. There are very few studies determining the evolution of this microbiota during tobacco storage, which may affect the quality of tobacco. Polymerase chain reaction (PCR) combined with denaturing gradient gel electrophoresis (DGGE) were used to determine changes in the microbiota of tobacco during the aging of eleven different tobacco grades stored at three different locations for twelve months. The microbial fraction of these tobacco grades was extracted, and the bacterial 16S and the fungal 18S ribosomal RNA gene (rDNA) sequences were PCR amplified before being segregated by DGGE. The bacterial complexity of the tobacco grades was represented by DGGE migrating banding profiles that varied between 20 and 30 bands. Some variations in the banding profiles were observed between the tobacco grades, but overall no substantial changes occurred in the bacterial population of the different grades during their storage at different locations. Most of the fungal DGGE profiles were identical and had only one dominating band related to the genus Aspergillus. Bacterial and fungal isolates were also derived from the microbial fractions of the tobacco, and part of their respective 16S and 18S rDNA sequences were determined. Bacterial isolates belonged to Bacillales and gamma Protobacteria. Fungal isolates belonged to the genus Aspergillus. Our results showed that the bacterial and fungal biota of tobacco are relatively stable throughout 12 months storage time.
- Accesso libero
The Influence of a Humectant on the Retention by Humans of Solanesol from Cigarette Smoke (Part 2, Glycerin)
Pagine: 378 - 383
Two common humectants are used as additives in the cigarette manufacturing process, propylene glycol (PG) and glycerin. The humectants may influence the deposition of cigarette smoke in the human respiratory tract by affecting the hygroscopic properties and growth of smoke particles. This study examines the influence of glycerin addition on the retention of solanesol by smokers. The influence of PG addition has been previously reported (7). The first cigarette used in the study (control) was a commercially available brand containing no additives in the blend (with a measured level of glycerin of 0.19%). The other cigarette (test) had an identical tobacco blend to the control, but had 2.3% added glycerin. The construction of the cigarette with 2.3% glycerin (test) was selected to match as closely as possible the ‘tar’ (as measured by Federal Trade Commission regimen), pressure drop (open and closed), and nicotine level of the commercial cigarette (control). Twelve smokers evaluated both products. The sample collection was performed using three cigarettes smoked within one hour. Each human subject smoked the control cigarette and then the test cigarette in two separate sessions. The exhaled smoke was collected using a vacuum assisted procedure designed to avoid strain in exhaling, and solanesol was analyzed using an high performance liquid chromatography (HPLC) technique. The cigarette butts from the smokers were collected and also analyzed for solanesol. The results obtained for the cigarette butts from the smokers were used to calculate the level of solanesol in the smoke delivered to the human subject, based on calibration curves. These curves were generated separately by analyzing the solanesol in smoke and in the cigarette butts obtained by machine smoking under different puffing regimes. Knowing the levels of delivered amount of solanesol and that in the exhaled smoke it was possible to calculate the retention of this compound from mainstream smoke for the two cigarette types. The amount of solanesol retained by the smoker (per cigarette) was on average 314.8 µg/cig with 18.9% relative standard deviation for the commercial cigarette, and 302.6 µg/cig with 20.3% relative standard deviation for the cigarette with 2.3% added glycerin. The retention % of solanesol from the commercial cigarette showed an average of 69.5% with 9.4% relative standard deviation, and the cigarette with 2.3% added glycerin showed an average retention of 69.4% with 10.5% relative standard deviation. Applying the paired t-test to the data it was found that there were no significant differences in the retention amount of solanesol, or in the retention % of solanesol for the two cigarettes. No correlation was found between the amount of solanesol delivered to the smoker (in µg/cig) and the solanesol retention % by the smoker.
- Accesso libero
The Composition of Cigarette Smoke. An Historical Perspective of Several Polycyclic Aromatic Hydrocarbons
Pagine: 384 - 410
Because of the significant advancements in fractionation, analytical, and characterization technologies since the early 1960s, hundreds of components of complex mixtures have been accurately characterized without the necessity of actually isolating the individual component. This has been particularly true in the case of the complex mixtures tobacco and tobacco smoke. Herein, an historical account of a mid-1950 situation concerning polycyclic aromatic hydrocarbons (PAHs) in cigarette smoke is presented. While the number of PAHs identified in tobacco smoke has escalated from the initial PAH, azulene, identified in 1947 to almost 100 PAHs identified by late 1963 to more than 500 PAHs identified by the late 1970s, the number of PAHs isolated individually and characterized by several of the so-called classical chemical means (melting point, mixture melting point, derivative preparation and properties) in the mid-1950s and since is relatively few, 14 in all. They were among 44 PAHs identified in cigarette mainstream smoke and included the following PAHs ranging from bicyclic to pentacyclic: Acenaphthylene, 1,2-dihydroacenaphthylene, anthracene, benz[