Cigarette smoke retention and bronchodilation in patients with COPD. A controlled randomized trial

Fast analysis of selected compounds in inhaled and exhaled vapor phase of cigarette smoke to evaluate components retained in the upper respiratory tract

RATIONALE

The aim of this work is to use a new design of online sampling photoionization mass spectrometer to analyze chemical ingredients in inhaled and exhaled cigarette smoke directly without separation.

METHODS

Based on vacuum ultraviolet photoionization time-of-flight mass spectrometry (VUV-PI-TOFMS) and a sampling system, a newly developed rapid online sampling design approach was used for the upper respiratory tract retention study of gaseous mainstream cigarette smoke components during smoking. The cigarette smoke inhaled or exhaled by seven subjects who displayed three different smoking patterns was directly sampled into a vacuum chamber, photoionized, and analyzed using TOFMS.

RESULTS

Fourteen species, comprising aldehydes, ketones, phenol, methanethiol, nitrogen-containing heterocyclic compounds and unsaturated hydrocarbons, were identified in the cigarette smoke obtained from Virginia-type cigarettes. The upper respiratory tract results for these compounds were similar for smokers with the three different smoking patterns: aldehyde and ketone constituents had a high retention level of more than 60%; phenol, methanethiol, and nitrogen-containing heterocyclic compounds were retained at between 30% and 70%; and the retention of unsaturated hydrocarbons was about 20%-60%. The retention trend of the same smoke components in Virginia-type cigarettes by subjects from the three smoking patterns (A, B, and C) was consistent, and the retentions all increased with increased smoking age (A < B < C).

CONCLUSIONS

This is the first report of a new online sampling design approach to the study of cigarette smoke components in inhaled and exhaled breath, to evaluate components retained in the upper respiratory tract by subjects with different smoking patterns. This method has good repeatability, and the results indicated that this is a very promising tool for the study of the retention of cigarette smoke constituents.

Lung deposition analyses of inhaled toxic aerosols in conventional and less harmful cigarette smoke: a review

Inhaled toxic aerosols of conventional cigarette smoke may impact not only the health of smokers, but also those exposed to second-stream smoke, especially children. Thus, less harmful cigarettes (LHCs), also called potential reduced exposure products (PREPs), or modified risk tobacco products (MRTP) have been designed by tobacco manufacturers to focus on the reduction of the concentration of carcinogenic components and toxicants in tobacco. However, some studies have pointed out that the new cigarette products may be actually more harmful than the conventional ones due to variations in puffing or post-puffing behavior, different physical and chemical characteristics of inhaled toxic aerosols, and longer exposure conditions. In order to understand the toxicological impact of tobacco smoke, it is essential for scientists, engineers and manufacturers to develop experiments, clinical investigations, and predictive numerical models for tracking the intake and deposition of toxicants of both LHCs and conventional cigarettes. Furthermore, to link inhaled toxicants to lung and other diseases, it is necessary to determine the physical mechanisms and parameters that have significant impacts on droplet/vapor transport and deposition. Complex mechanisms include droplet coagulation, hygroscopic growth, condensation and evaporation, vapor formation and changes in composition. Of interest are also different puffing behavior, smoke inlet conditions, subject geometries, and mass transfer of deposited material into systemic regions. This review article is intended to serve as an overview of contributions mainly published between 2009 and 2013, focusing on the potential health risks of toxicants in cigarette smoke, progress made in different approaches of impact analyses for inhaled toxic aerosols, as well as challenges and future directions.