Exposure to Secondhand Smoke and a Tobacco-Specific Carcinogen in Non-Smokers

High throughput and sensitive quantitation of tobacco-specific alkaloids and nitrosamines in wastewater

Tobacco-specific alkaloids and nitrosamines are important biomarkers for the estimation of tobacco use and human exposure to tobacco-specific nitrosamines that can be monitored by wastewater analysis. Thus far their analysis has used solid phase extraction, which is costly and time-consuming. In this study, we developed a direct injection liquid chromatography-tandem mass spectrometry method for the quantification of two tobacco-specific alkaloids and five nitrosamines in wastewater. The method achieved excellent linearity (R2 > 0.99) for all analytes, with calibration ranging from 0.10 to 800 ng/L. Method limits of detection and quantification were 0.17 ng/L (N-nitrosonornicotine, NNN) and 1.0 ng/L (N-nitrosoanatabine (NAT) and NNN), with acceptable accuracy (100 % ± 20 %) and precision (± 15 %). Analyte loss during filtration was < 15 %, and the relative matrix effect was < 10 %. The method was applied to 43 pooled wastewater samples collected from three wastewater treatment plants in Australia between 2017 and 2021. Anabasine and anatabine were detected in all samples at concentrations of 5.0 - 33 ng/L and 12 - 41 ng/L, respectively. Three of the five tobacco-specific nitrosamines (NAT, NNN, and (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol) (NNAL)) were detected, in < 50 % of the wastewater samples, with concentrations nearly ten times lower than the tobacco alkaloids (< 1.0 - 6.2 ng/L). In-sewer stability of the nitrosamines was also assessed in this study, with four (NAT, NNAL, NNN, and N-nitrosoanabasine (NAB)) being stable (i.e. < 20 % transformation over 12 h in both control reactor (CR) and rising main reactor (RM) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) being moderately stable (< 40 % loss over 12 h in RM). This direct injection method provides a high-throughput approach in simultaneous investigation of tobacco use and assessment of public exposure to tobacco-specific nitrosamines.

Association Between Second-Hand Smoke Exposure and Respiratory Symptoms Among the General Population of Non-smoker Adults in Saudi Arabia: A Cross-Sectional Study

BACKGROUND

Second-hand smoke (SHS) exposure is associated with respiratory symptoms such as cough, dyspnea, and wheezing. However, data on this association in Saudi Arabia is limited.

OBJECTIVES

The objective of this study is to investigate the prevalence of SHS exposure and its association with respiratory symptoms among non-smoker adults in Saudi Arabia.

METHODS

Data collection was carried out over the course of two months by distributing an online questionnaire among adults living in Saudi Arabia. The survey consisted of questions assessing sociodemographic factors, SHS exposure, and the presence of respiratory symptoms. Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 22 (Released 2013; IBM Corp., Armonk, New York, United States). Data was considered significant if p<0.05.

RESULTS

The questionnaire was completed by 1360 participants. Most were females (n=845, 72.1%) and individuals aged 18 to 30 years (n=838, 71.5%). From the analyzed records, 67.3% (n=789) reported SHS exposure. Among them, 40.3% (n=472) reported SHS exposure from household sources, 32.6% (n=382) from work colleagues, and 30.5% (n=357) from friends. The majority (n=306, 76.9%) of those exposed at home reported daily SHS exposure. The main source of home exposure was male family members, particularly the father (n=201, 42.6%). The majority (n=985, 84.0%) of participants reported not having any kind of mold or damage at their place of residence. Individuals with SHS exposure were more likely to report asthma (p=0.043), chest whistling or wheezing (p=0.021), chronic cough (p<0.001), productive cough (p<0.001), and nasal symptoms without a cold (p<0.001). These individuals also demonstrated a higher average symptom score than those not exposed to SHS.  Conclusion: The study reveals that a significant percentage of the Saudi population is exposed to SHS daily, mainly from household sources, especially male family members. A significant association was found between SHS exposure and the presence of respiratory symptoms. Public awareness regarding the prevalence and dangers of SHS exposure is essential in order to alleviate the impact of SHS on the health of the general Saudi population. Additionally, further research is required in this field and demographic group to develop appropriate interventions.

Short-Term Effects of Side-Stream Smoke on Nerve Growth Factor and Its Receptors TrKA and p75NTR in a Group of Non-Smokers

Environmental tobacco smoke remains a major risk factor, for both smokers and non-smokers, able to trigger the initiation and/or the progression of several human diseases. Although in recent times governments have acted with the aim of banning or strongly reducing its impact within public places and common spaces, environmental tobacco smoke remains a major pollutant in private places, such as the home environment or cars. Several inflammatory and long-term biomarkers have been analysed and well-described, but the list of mediators modulated during the early phases of inhalation of environmental tobacco smoke needs to be expanded. The aim of this study was to measure the short-term effects after exposure to side-stream smoke on Nerve Growth Factor and its receptors Tropomyosin-related kinase A and neurotrophin p75, molecules already described in health conditions and respiratory diseases. Twenty-one non-smokers were exposed to a home-standardized level of SS as well as to control smoke-free air. Nerve Growth Factor and inflammatory cytokines levels, as well the expression of Tropomyosin-related kinase A and neurotrophin receptor p75, were analysed in white blood cells. The present study demonstrates that during early phases, side-stream smoke exposure induced increases in the percentage of neurotrophin receptor p75-positive white blood cells, in their mean fluorescent intensity, and in gene expression. In addition, we found a positive correlation between the urine cotinine level and the percentage of neurotrophin receptor-positive white blood cells. For the first time, the evidence that short-term exposure to side-stream smoke is able to increase neurotrophin receptor p75 expression confirms the very early involvement of this receptor, not only among active smokers but also among non-smokers exposed to SS. Furthermore, the correlation between cotinine levels in urine and the increase in neurotrophin receptor p75-positive white blood cells could represent a potential novel molecule to be investigated for the detection of SS exposure at early time points.