Expired Air Carbon Monoxide Levels Research Articles

Assessment of a Text Message–Based Smoking Cessation Intervention for Adult Smokers in China

Successful smoking cessation strategies are an important part of reducing tobacco use. However, providing universal smoking cessation support can be a challenge for most countries because it requires sufficient resources. One way to expand access is to use mobile technologies to provide cessation support. To assess the efficacy of a behavior change theory-based smoking cessation intervention using personalized text messages. This study was a 2-arm double-blind randomized clinical trial conducted in 5 cities in China. Daily or weekly smokers 18 years or older were eligible for inclusion if they owned a mobile phone and used the WeChat social media app. A total of 722 participants were randomized to the intervention or control group between April 1 and July 27, 2021. Intervention group participants received a personalized text message-based smoking cessation intervention that was based on the transtheoretical model and protection motivation theory and developed by this study's investigators. Control group participants received a nonpersonalized text message-based smoking cessation intervention developed by the US National Cancer Institute. Both groups received 1 to 2 text messages per day for 3 months through the app. The primary outcome was the biochemically verified 6-month sustained abstinence rate, defined as the self-report of no smoking of any cigarettes after the designated quit date, which was validated biochemically by an expired air carbon monoxide level of less than 6 ppm at each follow-up point. A total of 722 participants (mean [SD] age, 41.5 [12.7] years; 716 men [99.2%]; all of Chinese ethnicity) were randomly assigned to the intervention group (360 participants) or the control group (362 participants). Biochemically verified continuous abstinence at 6 months was 6.9% in the intervention group and 3.0% in the control group (odds ratio [OR], 2.66; 95% CI, 1.21-5.83). Among smokers with low nicotine dependence, the intervention group had significantly better abstinence rates for most of the indicators after adjusting for covariates (eg, biochemically verified 24-hour point prevalence of abstinence at 1 month: adjusted OR, 2.15; 95% CI, 1.05-4.38). Among smokers with moderate and high nicotine dependence, only the biochemically verified 24-hour point prevalence of abstinence at 6 months was statistically significant (adjusted OR, 4.17; 95% CI, 1.34-3.00). The pattern was similar for quitting intention, and the personalized text message-based intervention was more effective for smokers who had strong quitting intention than for those who had weak quitting intention. In this study, the behavior change theory-based smoking cessation intervention using personalized text messages was more effective than an intervention using nonpersonalized text messages. The intervention was most effective among smokers with low nicotine dependence and strong quitting intention. This study's findings also provide further evidence regarding the potential benefits of mobile health interventions for other behaviors. Chinese Clinical Trial Registry Identifier: ChiCTR2100041942.

Effectiveness of National Residential Smoking Cessation Program.

We aimed to investigate the effectiveness of the Korean national five-day residential smoking cessation program and the factors affecting the long-term smoking cessation of participants. The residential smoking cessation program (2017–2018) recruited smokers with a smoking duration ≥ 20 years and who have attempted to quit smoking more than twice and/or smokers with chronic morbidities. Participants underwent an intensive intervention, including individual psychological therapy, group therapy, medical counseling, and pharmacotherapy. The 6-month continuous abstinence rate (CAR) was assessed via self-reports, the urine cotinine levels, and/or expired-air carbon monoxide levels. Logistic regression was used to analyze the adjusted odds ratio (aOR) to assess factors related to smoking cessation. Overall, 484 participants who completed the residential program and questionnaire were evaluated. The 3- and 6-month CAR were 81.82% and 63.22%, respectively. The aOR of 6-month continuous abstinence was lower among participants with severe nicotine dependence (aOR: 0.46, 95% confidence interval [CI]: 0.26–0.81) and higher among participants with combination therapy of varenicline with short-term nicotine replacement therapy (NRT) (aOR: 1.64, 95% CI: 1.07–2.51), with higher self-efficacy (aOR: 1.97, 95% CI: 1.15–3.37). The residential smoking cessation program was effective. High self-efficacy, combination therapy of varenicline with short-term NRT, and low nicotine dependence were associated with a high 6-month CAR.

Using graphic text-messaging to promote smoking cessation among first-generation Chinese and Korean male immigrants.

First-generation Chinese and Korean male immigrants in the United States are at high risk for tobacco use. This study pilot-tested a graphic, native-language text-messaging intervention to promote smoking cessation among these groups. First-generation Chinese and Korean male immigrant smokers (N = 71) were recruited from the Washington DC area. Participants were randomly assigned to one of four conditions based on a between-subjects 2 (graphic plus text or text-only messages) � 2 (quitline information or quitting tips) design. The text-messaging intervention included 30 text messages in total and lasted one month. Participants completed an expired air carbon monoxide (CO) assessment and self-reported measures at both baseline and follow-up. Results show that, from baseline to follow-up, participants' expired air CO levels decreased significantly (P = 0.001). Attitude toward quitting also became more positive (P = 0.028). Compared with text-only messages, graphic text messages produced greater positive changes in quitting attitudes (P = 0.039) and elicited greater fear response (P = 0.005). Compared with quitting tip messages, quitline information resulted in greater regret (P = 0.016) and fear (P = 0.051). These findings suggest that graphic text-messaging can be an effective method to promote smoking cessation among first-generation Chinese and Korean male immigrants.

Association between nicotine replacement therapy use in pregnancy and smoking cessation

BackgroundThere is an urgent need to find better ways of helping pregnant smokers to stop. Randomized controlled trials (RCTs) have not detected an effect of nicotine replacement therapy (NRT) for smoking cessation in pregnancy. This may be because of inadequate dosing because of faster nicotine metabolism in this group. In England, many pregnant smokers use single form and combination NRT (patch plus a faster acting form). This correlational study examined whether the latter is associated with higher quit rates. MethodsRoutinely collected data from 3880 pregnant smokers attempting to stop in one of 44 Stop Smoking Services in England. The outcome measure was 4-week quit rates, verified by expired-air carbon monoxide level<10ppm. Outcome was compared between those not using medication versus using single form NRT (patch or one of the faster acting forms), or combination NRT. Potential confounders were intervention setting (specialist clinic, home visit, primary care, other), intervention type (one-to-one, group, drop-in, other), months pregnant, age, ethnicity and occupational group in multi-level logistic regressions. ResultsAfter adjustment, combination NRT was associated with higher odds of quitting compared with no medication (OR=1.93, 95% CI=1.13–3.29, p=0.016), whereas single NRT showed no benefit (OR=1.06, 95% CI=0.60–1.86, p=0.84). ConclusionsUse of a combination of nicotine patch and a faster acting form may confer a benefit in terms of promoting smoking cessation during pregnancy. While this conclusion is based on correlational data, it lends support to continuing this treatment option pending confirmation by an RCT.

Cigarette Smoking Among Opioid‐Dependent Clients in a Therapeutic Community

This study examines smoking behavior in a sample of 231 opioid-dependent clients entering therapeutic community treatment, and investigates the relationship between smoking behavior and drug treatment outcomes. We applied regression analyses for selected Addiction Severity Index composites (alcohol, drug, medical, psychiatric), including factors for smoking (number of cigarettes per day, expired-air carbon monoxide level, nicotine dependence), time (baseline, 6 and 12-month), and smoking-by-time interaction. This study confirmed a high smoking prevalence (95%) among opioid users. Among participants interviewed at all time points (n = 206), 13% shifted from smoking to non-smoking status at some time after admission. Participants who reported a greater number of cigarettes were more likely to report higher drug severity at any time point.

Effectiveness of topiramate for tobacco dependence in patients with depression; a randomised, controlled trial

BackgroundTobacco dependence management is a multi-component intervention that includes pharmacological treatments such as Nicotine Substitution Therapy (NST) or bupropion, and psychological therapy. There are some preliminary reports on topiramate efficacy for tobacco dependence. The aim of this study is to determine whether topiramate is as effective as the standard NST treatment for tobacco cessation at 1-year follow-up in patients with depression.Method/designDesign: A randomised, controlled trial involving two groups, one of which is the control group consisting of patients on the standard pharmacological treatment for tobacco cessation (NST) and the other is the intervention group consisting of patients on topiramate as pharmacological treatment.Setting: 29 primary care health centres in the city of Zaragoza, Spain.Sample: 180 patients, aged 18–65 years, diagnosed with major depression, smoke more than 20 cigarettes/day, who have voluntarily asked for tobacco cessation therapy.Intervention: A multi-component programme for tobacco cessation is offered to all of the patients in the study. This programme is made up of pharmacological therapy + group cognitive-behavioural therapy. Pharmacological therapy consists of NST for the control group and topiramate (200 mg/day) for the intervention group. Psychological therapy is made up of 16 sessions of manualised group therapy.Measurements: Cessation will be assessed by patient self-declared abstinence, expired air carbon monoxide levels, and cotinine levels in saliva. Questionnaires on tobacco dependence, anxiety, depression, impulsiveness and self-efficacy will be administered. The interviewers will not know which group the patient belongs to (blind). The assessments will be carried out at baseline, D (cessation day) -1, D+1, weeks 1, 2, 3, 4, 6, 8, 10 and 13, and months 4, 5, 6, 8, 10 and 12.Main variables: Tobacco cessation rates and tobacco dependence.Analysis: The analysis will be per intent to treat. We will use the general linear models of the SPSS version 15 statistical package, to analyse the effect of the treatment on the result variable (tobacco cessation rate).DiscussionIt is necessary to develop new and more effective pharmacological treatments for tobacco cessation. This randomised clinical trial will determine whether topiramate is effective for tobacco cessation in patients with depression.Trial registrationCurrent Controlled Trials ISRCTN93532081

Experimentally‐Induced Spontaneous Opiate Withdrawal: Relationship to Cigarette Craving and Expired Air Carbon Monoxide

Smoking often increases after opioid use among those addicted to both opioids and nicotine, but the relationship between smoking and experimentally induced spontaneous opioid withdrawal (OW) has not been characterized. Six inpatient opioid-dependent smokers were stabilized on morphine 15 mg SC QID. Expired air carbon monoxide levels and smoking craving were measured for each participant on ten days when spontaneous OW was experimentally induced and on ten separate days in the absence of OW. Spontaneous OW was associated with significantly reduced carbon monoxide levels and smoking craving. Interestingly, craving was only reduced for items related to the positive reinforcing effects of smoking. These preliminary results suggest that OW may be a favorable context to initiate smoking cessation treatment interventions.

Effects of Biochemically Confirmed Smoking Cessation on White Blood Cell Count

To determine the relationship between white blood cell (WBC) Indices and several baseline variables In a large cohort of healthy smokers and to assess whether these changed after biochemically confirmed smoking cessation. The study consisted of 784 healthy smokers enrolled in a trial of sustained-release bupropion, 300 mg/d, for relapse prevention after smoking cessation from 1995 to 1998. Both WBC counts and absolute neutrophil counts (ANCs) were measured at baseline, week 7, and week 52. Smoking status was assessed at weeks 7 and 52 by self-report and biochemically confirmed with expired air carbon monoxide levels. Multivariate analyses compared changes in WBC count and ANC between smokers who did and did not stop smoking, adjusting for treatment group, age, sex, and body mass index. Of 784 smokers enrolled, 461 had biochemically confirmed tobacco abstinence after 7 weeks of bupropion; 429 were randomly assigned to receive continued bupropion therapy or placebo until week 52. Between baseline and week 7, there was a significantly larger decrease in WBC count in continuously abstinent subjects compared with continuing smokers (adjusted P = .03). At 52 weeks, continuously abstinent subjects, compared with continuing smokers, had a greater decline from baseline in WBC count (1.2 +/- 1.9 x 10(9)/L vs 0.1 +/- 1.9 x 10(9)/L; P < .001) and ANC (1.0 +/- 1.6 x 10(9)/L vs 0.2 +/- 1.5 x 10(9)/L; P < .001). Biochemically confirmed tobacco abstinence leads to a rapid and sustained decrease in WBC and ANC, possibly reflecting a decrease In an underlying state of tobacco-induced inflammation.

Veracity of Smokers' Response Regarding Abstinence at Smoking Cessation Clinics

To assess the reliability of smokers' response as criteria for measuring abstinence and the necessity or not of confirming abstinence with carbon monoxide (CO) measurement. A multicenter, prospective, longitudinal study was carried out on patients over 18 years of age from 5 smoking cessation clinics who underwent treatment with nicotine or bupropion. When the patient attended the clinic at 15, 30, 60, 90, and 180 days, abstinence was checked by self-reporting and expired-air CO levels. Sensitivity, specificity, and positive, negative, and overall predictive value of patient reporting, measured CO levels, and the 2 procedures in combination were calculated. A total of 904 smokers (476 men and 428 women) with a mean (SD) age of 42.51 (10.09) years were enrolled in the study. Of the 904 patients that made up the study population, 820, 776, 687, 719, and 679, respectively, attended the scheduled visits to check abstinence. Self-reported point-prevalence abstinence at 15 days was 74.5% and at 180 days was 57.6% while abstinence determined by expired-air CO was 75.7% and 59.4% respectively. Results according to self-reporting, CO measurement, and the 2 methods in combination were not significantly different (P<.05) at any of the points in time. Neither sensitivity nor specificity showed significant differences in relation to patient variables. The reliability of self-reported abstinence from smoking is high. Measurement of CO is therefore not essential, although it could be advisable for motivating patients rather than as a way of confirming abstinence.

Effects of Biochemically-Confirmed Smoking Cessation on Periperhal Leukocyte Count.

BACKGROUND: Previous work has demonstrated that smokers have higher white blood cell counts than nonsmokers, but the effect of biochemically-confirmed smoking cessation on peripheral leukocyte counts has not been demonstrated in a large prospective study.METHODS: Subjects were healthy smokers enrolled in a trial of sustained-release bupropion for relapse prevention after smoking cessation. White blood cell (WBC) counts and absolute neutrophil counts (ANC) were measured at baseline, week 7 and week 52. Smoking status was assessed at weeks 7 and 52 by self-report and biochemically confirmed with expired air carbon monoxide levels. Multivariate analyses compared changes in WBC count and ANC between smokers who did and did not stop smoking, adjusting for treatment group, age, sex, and body mass index.RESULTS: Of 784 smokers enrolled, 461 had biochemically-confirmed tobacco abstinence after 7 weeks of bupropion; 429 were randomly assigned to receive continued bupropion or placebo until week 52. At baseline, the mean WBC count was 8.4 x 109/L (SD ±2.3) and the mean ANC was 5.3 x 109/L (SD ±1.9). The baseline WBC count and ANC were higher in smokers with greater tobacco exposure, measured by daily cigarette consumption and serum cotinine level. Between baseline and week 7, there was a significantly larger decrease in WBC count in continuously abstinent subjects compared with continuing smokers (adjusted p =.031). At 52 weeks, biochemically-confirmed continuously abstinent subjects, as compared with continuing smokers, had a greater decline from baseline in WBC count (1.2 x 109/L versus 0.1 x 109/L, p<0.001) and ANC (0.1 x 109/L versus 0.2 x 109/L, p<0.001).CONCLUSION: The WBC count and ANC of healthy smokers increase with increasing tobacco exposure. Biochemically-confirmed tobacco abstinence leads to a rapid and sustained decrease in WBC count and ANC, possibly reflecting a decrease in an underlying state of tobacco-induced inflammation.

Can cumulative tobacco consumption, FTND score, and carbon monoxide concentration in expired air be predictors of chronic obstructive pulmonary disease?

Between 15% and 20% of smokers develop chronic obstructive pulmonary disease (COPD). The aim of the present study was to determine which characteristics of smoking, particularly the Fagerström Test for Nicotine Dependence (FTND) score, were associated with the risk of developing COPD. Data from the IBERPOC epidemiological study were analyzed. IBERPOC was a multicenter epidemiological study including 4035 individuals aged 40-69 years, 1023 (25%) of whom were active smokers. We analyzed the association between smoking characteristics--such as the cumulative consumption of tobacco, FTND score, and expired-air carbon monoxide levels--and the diagnosis of COPD. Among the smokers, 153 (15%) were diagnosed with COPD. A cumulative tobacco consumption of more than 30 pack-years (OR=4.24, 95% CI=2.83-6.36) and the FTND score (OR=1.11, 95% CI=1.02-1.21, for each point increase) were significantly associated with the diagnosis of COPD in the model obtained by logistic regression analysis with the full sample of smokers. Cumulative consumption of tobacco was associated with the diagnosis of COPD. For each point increase in the FTND score, the probability of a smoker developing COPD increased by 11%.

Blocking cigarette filter vents with lips more than doubles carbon monoxide intake from ultra-low tar cigarettes.

Light and ultra-light cigarettes achieve their lower tar, nicotine, and carbon monoxide (CO) yields on smoking machines largely by means of air-dilution vents on the filters. Previous research showed that blocking 0%, 50%, and 100% of the filter vents on a 1 mg tar cigarette with tape directly increased expired air CO levels. The present experiment extended this research by replicating the 0% blocked and 100% blocked conditions with the addition of a condition in which participants (N = 12) were asked to block vents with their lips. Mean CO boosts for the unblocked, lip-blocked, and tape-blocked conditions were 2.7 ppm (SE = 0.52), 6.7 ppm (SE = 1.0), and 12.9 ppm (SE = 2.2), respectively. Analyses suggested that lip blockade effectively blocked approximately 50% of the filter vents. Subjective ratings of cigarette strength, harshness, and heat increased significantly as degree of vent blocking increased. Cigarette smokers need to be warned about the presence of vents and the consequences of vent blocking.

Predicting Smoking Cessation

<h3>Objective.</h3> —To identify predictors of smoking cessation success or failure with and without transdermal nicotine patch treatment. <h3>Design.</h3> —Two independent randomized, double-blind, placebo-controlled studies using the nicotine patch assessing outcome at the end of treatment and at 6-month follow-up; each study used a different mode of adjuvant counseling. <h3>Patients.</h3> —Subjects were daily smokers (≥15 cigarettes per day), aged 21 to 65 years with expired air carbon monoxide levels of at least 10 ppm, and motivated to quit. Eighty-eight subjects participated in study 1, and 112 subjects participated in study 2. <h3>Intervention.</h3> —Study 1 consisted of 8 weeks of 22-mg nicotine patch therapy with intensive group counseling. Study 2 consisted of 4 weeks of 22-mg nicotine patch therapy and 2 weeks of 11-mg nicotine patch therapy with brief individual counseling. <h3>Main Outcome Measures.</h3> —The prediction of smoking cessation (at end of treatment and after 6 months) based on pretreatment and intratreatment measures in smokers using active or placebo nicotine patches. <h3>Results.</h3> —Pretreatment markers, such as the Fagerstrom Tolerance Questionnaire score, number of cigarettes smoked per day, years smoked, expired air carbon monoxide level, or baseline blood nicotine and cotinine levels, showed no consistent relationship with successful smoking cessation across both studies. Of the intratreatment markers examined, withdrawal severity and nicotine replacement levels also were not consistently predictive of cessation success. However, any smoking during the second week of treatment was a consistent and powerful predictor of failure at the end of treatment and after 6 months. Among active nicotine patch patients who smoked at all during week 2 after quitting, 83% and 97% (studies 1 and 2, respectively) were smoking at 6-month follow-up. Conversely, abstinence during the second week of treatment predicted successful smoking cessation. Among active nicotine patch patients who were totally abstinent during week 2 after quitting, 46% and 41% (studies 1 and 2, respectively) were abstinent at 6-month follow-up. Of all nicotine patch patients in both studies who were smoking at 6-month follow-up, 74% began smoking during week 1 or 2. Among all placebo patch patients who were smoking at 6-month follow-up, 86% began smoking during week 1 or 2. <h3>Conclusions.</h3> —Smoking status (abstinent or smoking) during the first 2 weeks of nicotine patch therapy, particularly week 2, was highly correlated with clinical outcome and can serve as a powerful predictor of smoking cessation. Early smoking behavior also predicted outcome among placebo patch users. Traditional measures of dependence are not consistently predictive of cessation success. Clinicians are advised to emphasize the importance of total abstinence after a quit attempt and to follow-up with patients within the first 2 weeks of quitting; smoking during this critical time should be assessed and treatment may be altered as appropriate. (<i>JAMA</i>. 1994;271:589-594)

Nicotine Patch Therapy for Smoking Cessation Combined With Physician Advice and Nurse Follow-up

To determine the efficacy of a 22-mg nicotine patch combined with the National Cancer Institute program for physician advice and nurse follow-up in providing withdrawal symptom relief, 1-year smoking cessation outcome, and percentage of nicotine replacement. Randomized, double-blind, placebo-controlled trial. Two-hundred forty healthy volunteers who were smoking at least 20 cigarettes per day. Based on the National Cancer Institute program, subjects received smoking cessation advice from a physician. Follow-up and relapse prevention were provided by a study nurse during individual counseling sessions. Subjects were randomly assigned to 8 weeks of a 22-mg nicotine or placebo patch. Abstinence from smoking was verified by expired air carbon monoxide levels. Withdrawal symptoms were recorded during patch therapy, and the percentage of nicotine replacement was calculated by dividing serum nicotine and cotinine levels at week 8 of patch therapy by levels obtained while smoking. Higher smoking cessation rates were observed in the active nicotine patch group at 8 weeks (46.7% vs 20%) (P < .001) and at 1 year (27.5% vs 14.2%) (P = .011). Higher smoking cessation rates were also observed in subjects assigned to the active patch who had lower serum levels of nicotine and cotinine at baseline, and withdrawal symptom relief was better in the active patch group compared with placebo. Clinically significant smoking cessation can be achieved using nicotine patch therapy combined with physician intervention, nurse counseling, follow-up, and relapse prevention. Smokers with lower baseline nicotine and cotinine levels had better cessation rates, which provides indirect evidence that they had more adequate nicotine replacement with this fixed dose of transdermal nicotine than those smokers with higher baseline levels.

Changes in Adult Cigarette Smoking Prevalence after 5 Years of Community Health Education: The Stanford Five-City Project

To determine the effects of 5 years of community-wide cardiovascular health education on smoking prevalence and cessation, the authors analyzed data from the Stanford Five-City Project, an experimental field study with two treatment cities and two control cities. Representative samples of the population aged 12-74 years were drawn at baseline and every 2 years thereafter to obtain four independent cross-sectional surveys; participants aged 25-74 years are included in this paper (n approximately 440 per city per survey; total n = 6,981). The baseline sample was asked to return to three follow-up surveys, also 2 years apart, and those that did (n = 805) constitute the cohort survey sample. Self-reported cigarette smoking was confirmed by plasma thiocyanate and expired-air carbon monoxide levels. Smoking prevalence decreased over time in all cities, but in the cohort the decrease tended to be greater in treatment than in control cities (p = 0.10, two-tailed); the treatment-control difference was consistent over time (-1.51 percentage points/year in treatment vs. -0.78 percentage points/year in control, p = 0.007, two-tailed). In contrast, smoking prevalence in the independent samples declined similarly in treatment and control cities, changes were not linear, and rates varied within cities between times. Baseline smokers in both the cohort and the follow-up independent surveys were significantly more likely to quit in the treatment cities than in the control cities.

Improved CO monitors for validating smoking abstinence by expired‐air carbon monoxide level

Improved CO monitors for validating smoking abstinence by expired‐air carbon monoxide level

Cigarette smoking and employment status

The smoking habits and health knowledge of the unemployed and the full-time workers were investigated in a cross-sectional study of over 10,000 men and women throughout Scotland. For both sexes (age range 40–59 years), the proportion of current smokers and ever smokers was found to be considerably higher among the unemployed. Only a small part of the difference could be explained by standardisation for social class. The unemployed smokers had began to smoke at an earlier age, with significantly more smoking whilst still at school. Amongst current smokers, the unemployed males reported smoking fewer cigarettes a day, whereas unemployed women smoked more than their full-time counterparts. The reported levels were confirmed by the biochemical measures of smoking; serum thiocyanate and expired air carbon monoxide levels. In contrast to their differences in smoking habit, the two groups were very similar in their knowledge of the hazards of smoking. Smoking habits among the unemployed reflect a complex interaction of financial and both current and previous social factors. Such relationships present a particular challenge to health promotion campaigns.

Tea drinking, passive smoking, smoking deception and serum cotinine in the Scottish heart health study

Following a recent claim that the use of cotinine in body fluids, to assess passive smoking and smoking “deception”, was confounded by metabolic individuality, and by non-tobacco sources of dietary nicotine, particularly tea, data were examined from a large cross-sectional survey in a tea-drinking population. In 3383 men and women aged 44–59 years from the Scottish Heart Health Study, defined as non-smokers, both by self-report and by low thiocyanate and expired air carbon monoxide levels, serum cotinine showed minimal association with self-reported daily average tea consumption. However, there was a strong correlation between degree of self-reported passive tobacco smoke exposure and median serum cotinine level. In the same survey, serum cotinine in 4144 self-reported non-smokers and in 3326 smokers showed entirely different distributions, but the same range, suggesting heavy nicotine intake in some “non-smokers”. These analyses confirm that cotinine levels in true non-smokers reflect far more the nicotine in inhaled ambient tobacco smoke than they do nicotine in tea. Some smoking “deceivers” have the same degree of exposure to nicotine as heavy smokers. Despite individual variability, the claim of confounding is poorly supported, and cotinine is confirmed as an indicator both of passive smoking and of smoking deception.

WHERE THERE'S SMOKE…CARBON MONOXIDE EXPOSURES IN SMOKING AND SMOKE‐FREE WORKPLACES

Comparisons of expired air carbon monoxide levels in non‐smoking staff in six licensed clubs (a smoking workplace) were made with those of non‐smoking staff of a large public hospital (a smoke‐free workplace).There was a significant difference between clubs and hospital in levels of CO at end of work. The average concentration of club workers was 8.7 ppm (Hospital, 5.3 ppm). Approximately one third of these non‐smokers in licensed clubs exceeded 10 ppm putting them in the 'light smoker’ category according to the manufacturer of the monitoring equipment. Club workers increased their CO level during work time by four times the increase of Hospital staff. This study suggests that there are significant gains to be made in reduction of intake of harmful passive‐smoking products by removing tobacco smoke from workplaces.

Abstinence from smoking and expired-air carbon monoxide levels: lactose intolerance as a possible source of error.

We investigated a possible source of contamination of expired-air carbon monoxide (CO) readings on CO monitors from raised expired-air hydrogen (H2) levels, namely lactose intolerance, the norm in certain ethnic groups. A significant correlation between expired-air CO and H2 readings was observed in four non-smoking lactose maldigesters.