Smokers' behaviour and exposure according to cigarette yield and smoking experience

Risk assessment of toxicants on WHO TobReg priority list in mainstream cigarette smoke using human-smoked yields of Korean smokers

Recently, the World Health Organization Study Group on Tobacco Product Regulation (WHO TobReg) announced a priority list of 38 toxicants among the more than 7000 chemicals found in cigarette smoke, building upon previous lists of toxicants in cigarette smoke. Here, we conducted a comprehensive study on the quantitative exposure and risk characterization of these priority toxicants in mainstream cigarette smoke listed by the WHO TobReg. The human-smoked toxicant yields estimated from spent cigarette butts of a total of 361 smokers using the part-filter method (PFM) were applied to current exposure and risk estimation for the first time. The PFM can estimate human-smoked yields of toxicants using smokers' maximum mouth-level exposure. The human-smoked yield of each toxicant was converted to systemic uptake by considering bioavailability. Risk indicators-including the incremental lifetime cancer risk (ILCR), cumulative ILCR, hazard quotient (HQ), hazard indices (HIs), and margin of exposure (MOE)-were estimated from the systemic uptake of toxicants combined with Korean exposure factors by gender and age group as well as for total smokers. It was demonstrated that cigarette smoking results in significant cancer and non-cancer health risks. A sensitivity analysis showed that the human-smoked toxicant yield is one of the most important contributors to risk level variations. Our risk estimation suggested that previous risk assessments might have ignored or underestimated the uncertainty of risk assessment. In conclusion, we assessed the risk level of the 38 toxicants on the priority list developed by the WHO TobReg and provided a Korean-specific priority list for the regulations on the emission of cigarette smoke.

Cigarette Filter Ventilation and its Relationship to Increasing Rates of Lung Adenocarcinoma

The 2014 Surgeon General's Report on smoking and health concluded that changing cigarette designs have caused an increase in lung adenocarcinomas, implicating cigarette filter ventilation that lowers smoking machine tar yields. The Food and Drug Administration (FDA) now has the authority to regulate cigarette design if doing so would improve public health. To support a potential regulatory action, two weight-of-evidence reviews were applied for causally relating filter ventilation to lung adenocarcinoma. Published scientific literature (3284 citations) and internal tobacco company documents contributed to causation analysis evidence blocks and the identification of research gaps. Filter ventilation was adopted in the mid-1960s and was initially equated with making a cigarette safer. Since then, lung adenocarcinoma rates paradoxically increased relative to other lung cancer subtypes. Filter ventilation 1) alters tobacco combustion, increasing smoke toxicants; 2) allows for elasticity of use so that smokers inhale more smoke to maintain their nicotine intake; and 3) causes a false perception of lower health risk from "lighter" smoke. Seemingly not supportive of a causal relationship is that human exposure biomarker studies indicate no reduction in exposure, but these do not measure exposure in the lung or utilize known biomarkers of harm. Altered puffing and inhalation may make smoke available to lung cells prone to adenocarcinomas. The analysis strongly suggests that filter ventilation has contributed to the rise in lung adenocarcinomas among smokers. Thus, the FDA should consider regulating its use, up to and including a ban. Herein, we propose a research agenda to support such an effort.

Validation of selected analytical methods using accuracy profiles to assess the impact of a Tobacco Heating System on indoor air quality

Studies in environmentally controlled rooms have been used over the years to assess the impact of environmental tobacco smoke on indoor air quality. As new tobacco products are developed, it is important to determine their impact on air quality when used indoors. Before such an assessment can take place it is essential that the analytical methods used to assess indoor air quality are validated and shown to be fit for their intended purpose. Consequently, for this assessment, an environmentally controlled room was built and seven analytical methods, representing eighteen analytes, were validated. The validations were carried out with smoking machines using a matrix-based approach applying the accuracy profile procedure. The performances of the methods were compared for all three matrices under investigation: background air samples, the environmental aerosol of Tobacco Heating System THS 2.2, a heat-not-burn tobacco product developed by Philip Morris International, and the environmental tobacco smoke of a cigarette. The environmental aerosol generated by the THS 2.2 device did not have any appreciable impact on the performances of the methods. The comparison between the background and THS 2.2 environmental aerosol samples generated by smoking machines showed that only five compounds were higher when THS 2.2 was used in the environmentally controlled room. Regarding environmental tobacco smoke from cigarettes, the yields of all analytes were clearly above those obtained with the other two air sample types.

ENDOGENOUS CARBON MONOXIDE CONCENTRATION IN BLOOD ELEVATES IN ACUTE CORONARY SYNDROME OF NONSMOKER POPULATION

BACKGROUND

Carbon monoxide (CO) was previously only considered as a highly toxic pollutant since it binds to hemoglobin with high affinity. Recently, however, it has been recognized as a signaling molecule with regulatory roles in many physiological and pathophysiological processes within the cardiovascular system. The aim of this study was to clarify the behavior of CO in patients with acute coronary syndrome (ACS).

METHODS

We assessed 235 patients with suspected ACS, 98 smokers (88 male, 62 ± 14 years) and 137 nonsmokers (77 male, 72 ± 13 years), who had undergone emergent cardiac catheterization and blood sampling for calculation of carboxyhemoglobin (COHb). Patients were categorized into 4 groups: smoking patients with ACS (n=77), smoking patients without ACS (n=21), non-smoking patients with ACS (n=97), and non-smoker patients without ACS (n=40). We investigated whether biomarkers were related to COHb levels.

RESULTS

LogCOHb was significantly higher in the smoking patients compared to non-smoking patients (0.30 ± 0.12 vs. 0.45 ± 0.18, P < 0.01). Interestingly, among the non-smoking patients, COHb was increased in the ACS patients compared to the non ACS patients (0.31 ± 0.12 vs. 0.25 ± 0.12 P < 0.01). In contrast, among the smoking patients, there was no difference in COHb between the ACS and non-ACS patients (0.45 ± 0.18 vs. 0.44 ± 0.18, n.s.). There were no correlations between COHb and any of the biomarkers.

CONCLUSIONS

These results suggest that endogenous CO may be useful to assess the risk of cardiovascular stress.

Mercapturic Acids Derived from the Toxicants Acrolein and Crotonaldehyde in the Urine of Cigarette Smokers from Five Ethnic Groups with Differing Risks for Lung Cancer

The Multiethnic Cohort epidemiology study has clearly demonstrated that, compared to Whites and for the same number of cigarettes smoked, African Americans and Native Hawaiians have a higher risk for lung cancer whereas Latinos and Japanese Americans have a lower risk. Acrolein and crotonaldehyde are two important constituents of cigarette smoke which have well documented toxic effects and could play a role in lung cancer etiology. Their urinary metabolites 3-hydroxypropylmercapturic acid (3-HPMA) and 3-hydroxy-1-methylpropylmercapturic acid (HMPMA), respectively, are validated biomarkers of acrolein and crotonaldehyde exposure. We quantified levels of 3-HPMA and HMPMA in the urine of more than 2200 smokers from these five ethnic groups, and also carried out a genome wide association study using blood samples from these subjects. After adjusting for age, sex, creatinine, and total nicotine equivalents, geometric mean levels of 3-HPMA and HMPMA were significantly different in the five groups (P < 0.0001). Native Hawaiians had the highest and Latinos the lowest geometric mean levels of both 3-HPMA and HMPMA. Levels of 3-HPMA and HMPMA were 3787 and 2759 pmol/ml urine, respectively, in Native Hawaiians and 1720 and 2210 pmol/ml urine in Latinos. These results suggest that acrolein and crotonaldehyde may be involved in lung cancer etiology, and that their divergent levels may partially explain the differing risks of Native Hawaiian and Latino smokers. No strong signals were associated with 3-HPMA in the genome wide association study, suggesting that formation of the glutathione conjugate of acrolein is mainly non-enzymatic, while the top significant association with HMPMA was located on chromosome 12 near the TBX3 gene, but its relationship to HMPMA excretion is not clear.

Status epilepticus and cardiopulmonary arrest in a patient with carbon monoxide poisoning with full recovery after using a neuroprotective strategy: a case report

Introduction

Carbon monoxide poisoning can be associated with life-threatening complications, including significant and disabling cardiovascular and neurological sequelae.

Case presentation

We report a case of carbon monoxide poisoning in a 25-year-old Saudi woman who presented to our facility with status epilepticus and cardiopulmonary arrest. Her carboxyhemoglobin level was 21.4 percent. She made a full recovery after we utilized a neuroprotective strategy and normobaric oxygen therapy, with no delayed neurological sequelae.

Conclusions

Brain protective modalities are very important for the treatment of complicated cases of carbon monoxide poisoning when they present with neurological toxicities or cardiac arrest. They can be adjunctive to normobaric oxygen therapy when the use of hyperbaric oxygen is not feasible.

Gas geyser--a cause of fatal domestic carbon monoxide poisoning

Carbon monoxide is responsible for a large number of accidental domestic poisoning and deaths throughout the world. Domestic carbon monoxide poisoning is rarely reported in India and remains an under recognized problem. The diagnosis of carbon monoxide poisoning is usually based on autopsy findings, circumstantial evidence and estimation of carboxy-haemoglobin in blood. We report a case of fatal accidental carbon monoxide poisoning in a bathroom where an LPG gas water heater was installed recently. Cherry pink discolouration of the body and organs on autopsy suggested carbon monoxide poisoning. Laboratory analysis of blood by UV visible spectrophotometry revealed presence of dangerous levels of carboxy-haemoglobin. Effective preventive measures can help in bringing down the mortality and morbidity associated with carbon monoxide poisoning.

Mouth level smoke exposure using analysis of filters from smoked cigarettes: a study of eight countries

The analysis of spent cigarette filters enables the estimation of the nicotine and tar (nicotine-free dry particulate matter) yields obtained by smokers in their everyday environment and has been shown to correlate well with biomarkers of exposure. Leading products across the range of ISO tar yields were selected from Australia, Brazil, Canada, Germany, Japan, New Zealand, South Africa and Switzerland. At least fifty demographically representative smokers were recruited per product. Subjects, ≥ 21 years of age and smoking ≥ 5 cigarettes per day, were asked to collect ≥ 15 filters from cigarettes they had smoked. The collected filters were analysed for nicotine and UV absorbance to enable the smokers' mouth level exposure to nicotine and tar to be estimated and a comparison of countries and tobacco blend styles to be made. Smoking history data were also collected. More than 80,000 filters were collected from 5703 smokers of 106 products from eight countries. Mean ± SD estimated nicotine exposures per cigarette and per day ranged from 0.93 ± 0.34 mg/cigarette (Brazil) to 1.77 ± 0.69 mg/cigarette (South Africa) and from 16.4 ± 11.1mg/day (Germany) to 31.5 ± 14.8 mg/day (South Africa), respectively. Male smokers obtained higher mean estimated tar and nicotine exposures than female smokers. These gender differences were statistically significant for six countries. Significant correlations were found between estimated nicotine exposure and ISO nicotine yield, and between estimated tar exposure and ISO tar yield (p<0.001).

Estimation of nicotine and tar yields from human-smoked cigarettes before and after the implementation of the cigarette ignition propensity regulations in Canada

In 2005, Human-Smoked (HS) tar and nicotine yields from commercial Canadian cigarettes were determined using a part filter analysis method to obtain estimates representative of human smoking behavior. In 2006, new cigarette designs were introduced to ensure compliance with the Canadian Low Ignition Propensity (LIP) regulations. It was not known how the changes in product design would affect HS yields. To assess the impact of the cigarette design modifications on HS yields, a further group of Canadian smokers was recruited for smoking the modified version of 10 products previously assessed. No differences in estimated HS tar yields were found between products following product modification. The HS nicotine yield was different for one product. In general, HS yields were higher than ISO machine yields while Canadian intense machine yields were more representative of the maximum HS yields. The same product ranking order was obtained for HS yields and the two machine yields but differences between the mean HS yields and ISO yields were smaller as the product ISO yields increased. Higher HS yields were measured when products were smoked by male smokers. The methodology used in this study showed the wide range of HS yields obtained by smokers as well as a good degree of stability in average HS yields just before and after the introduction of LIP regulations.

Estimation and correlation of cigarette smoke exposure in Canadian smokers as determined by filter analysis and biomarkers of exposure

A clinical study conducted in Canada compared two methods of estimating exposure to cigarette smoke in 192 volunteer subjects: 43 smokers of 4-6 mg, 49 of 8-12 mg and 50 of 14-15 mg ISO tar yield cigarettes and 50 non-smokers. Estimates of mouth level exposure (MLE) to nicotine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), pyrene and acrolein were obtained by chemical analysis of spent cigarette filters. Estimates of smoke constituent uptake were achieved by analysis of urinary biomarkers for total nicotine equivalents (nicotine, cotinine, trans-3'-hydroxycotinine plus their glucuronide conjugates), NNK (total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) plus glucuronide), pyrene (1-hydroxy pyrene plus glucuronide) and acrolein (3-hydroxylpropyl-mercapturic acid) plus the nicotine metabolite cotinine in plasma and saliva. The objective of our study was to confirm the correlations between measures of human exposure obtained by filter analysis and biomarkers. Significant correlations (p<0.001) were found between MLE and the relevant biomarker for each smoke constituent. The adjusted values of the Pearson correlation coefficients (r) were 0.80 (nicotine), 0.77 (acrolein) and 0.44 (pyrene). NNK correlations could not be obtained because of the low NNK yield of Canadian cigarettes. Unexpectedly high levels of acrolein biomarker found in non-smokers urine on one of the two days sampled emphasised the need for more than one sampling occasion per period and an awareness of non-tobacco sources of smoke constituents under investigation. No consistent dose response, in line with ISO tar yield smoked, of MLE estimates was found for nicotine, pyrene and acrolein and respective biomarkers. The influence of demographics on our results has also been examined.

A survey of mouth level exposure to cigarette smoke in the United States

Smoke yields determined by a machine-based smoking method cannot adequately predict exposures experienced by human smokers. In this work, a filter analysis technique which addresses this fundamental limitation was used to measure mouth level exposures (MLE) to tar and nicotine in 1330 smokers of 26 brand-styles of US cigarettes covering a wide range of machine-generated yields. Despite the high degree of variability observed among individual smokers, MLEs were significantly correlated with machine-derived tar and nicotine yields (r=0.423 for nicotine MLE/cigarette; r=0.493 for tar MLE/cigarette; p<0.001 for both). Mean tar and nicotine MLE was higher for males than for females. Mean MLE across races was generally similar. Menthol cigarettes tended toward lower MLE than non-menthol cigarettes and King-Size cigarettes (≈ 83 mm) tended toward lower MLE than 100's cigarettes (≈ 100 mm), though those trends were not statistically significant. There were good agreements between MLEs measured in a group of 159 subjects smoking their usual cigarette brand-style on two separate occasions and between two independent groups of subjects smoking the same brand-styles. The results indicated that the filter analysis method used had sufficient precision to show similarity among groups.

Limitations in the characterisation of cigarette products using different machine smoking regimes

It is recognised that no single machine smoking regime can represent the different behaviours of individual human smokers. It has been argued that the current ISO standard regime provides machine yields that are somewhat low for certain cigarette designs compared to human intake. Various cigarette machine smoking regimes have been proposed as options for regulatory use to provide data that reflect "average" or "maximum" yields as related to human intake. Some public health representatives have proposed that the intense regime mandated for testing in Canada with 100% of the ventilation holes in the cigarette filter blocked, should be used for product characterisation and that it is not necessary that it should reflect general human smoking behaviour. We believe that this is a flawed approach because our studies and those of other workers demonstrate that the conditions generated in the cigarette when using this intense machine smoking regime are extreme in comparison to the conditions found for regimes based more realistically on human smoking. In this paper, we provide data to show that smokers modify their smoking intensity over the course of smoking in response to changes in draw resistance, smoke concentrations and smoke temperatures. We compare changes in and interactions between these parameters during puffing when smoking cigarettes of different designs. Cigarettes were smoked using various machine smoking regimes previously proposed for smoke testing as well as a regime based on human smoking data from an 'in-house' study. Puffing parameters were derived from this study to represent the 'average smoker' under laboratory conditions and equivalent to the 90th percentile when the studied smokers smoked under natural conditions. Biomarker data from human uptake studies have shown that ventilation is an effective cigarette design tool to reduce total smoke constituent uptake in humans so demonstrating that any blocking of filter ventilation is far from 100%. Likewise, this current work also shows how smokers modify their smoking behaviour in ways not well reflected by the 100% ventilation blocking regime. It seems logical that any machine smoking regime chosen for future product regulation should reflect these findings for it to have valid public health relevance. In addition, it seems misguided to discourage product design features, such as ventilation, which clearly can provide products with reduced human smoke exposure, just to maintain the dogma, counter to the scientific evidence, that there must be a regulatory regime with 100% ventilation blocking.

Post-puff respiration measures on smokers of different tar yield cigarettes

The purpose of this study was to determine the effect of different tar yield cigarette brands on the post-puff inhalation/exhalation depth and duration for established smokers of the brands. The study was conducted with 74 established smokers of 1-17 mg Federal Trade Commission (FTC) tar products. The subjects were participating in a five-day inpatient clinical biomarker study during which time they were allowed to smoke their own brand of cigarette whenever they wished. On two separate days, the subjects' breathing pattern was measured using respiratory inductive plethysmography while they smoked one cigarette. This enabled the measurement of the post-puff inhalation volume, exhalation volume, inhalation duration, and exhalation duration for each subject after each puff on two of their own brand of cigarettes. The subjects were grouped according to the FTC tar yield of their product: 1-3 mg; 4-6 mg; 7-13 mg; 14 + mg. The post-puff inhalation volume for the 4-6 mg group was significantly lower than both the 7-13 mg and 14+ mg groups, and the 4-6 mg group exhalation volume was significantly lower than the 14+ mg group (p < 0.05). No other differences were found at the 95% confidence level. When volumes were normalized to resting tidal volume (tidal ratio), there were no differences between the groups for any of the respiratory measures. No significant slope was found for correlations with FTC tar yield for inhalation volume (p = 0.11, mean = 833 mL, R = 0.19), inhalation tidal ratio (p = 0.93, mean = 1.73, R = -0.01) or lung exposure time (p = 0.92, mean = 4.1 s, R = -0.01).

Time spent with smoking parents and smoking topography in adolescents

Although the relationship between parental and adolescent smoking has been linked to health consequences of smoking, limited study has explored the specific association between exposure to smoking and adolescent smoking topography (the way a cigarette is smoked). As a first step in this line of enquiry, smoking topography measures were collected from 67 adolescent dependent smokers. Participants smoked one cigarette of their own brand while being monitored by a computer-based smoking-topography unit and completed questionnaires about their time spent daily with parents who smoke. Pearson's correlation analysis revealed that time spent daily with parents who smoke was significantly associated with maximum puff velocity (r=0.285, p=.019), a parameter predicting later pulmonary morbidity. ANOVAs, after a median split, were consistent with correlation analyses. There was a significant group effect on puff velocity (F(2,66)=5.197, p=.008); no significant relationship was found with puff volume (F(2,66)=.617) or puff duration (F(2,66)=.776). A post hoc Tukey HSD test indicated puff velocity was higher in the "high time spent" (M=54.37, SD=12.03) than in the "low time spent" group (M=45.59, SD=9.91) and in the group with non-smoking parents (M=44.96, SD=10.17). Future research with a larger non-treatment seeking sample of adolescents aimed at preventing tobacco smoking related diseases should further examine parental influences on adolescent smoking, including potential modeling effects.

A randomized, controlled exposure study in adult smokers of full flavor Marlboro cigarettes switching to Marlboro Lights or Marlboro Ultra Lights cigarettes

Rationale. To date no state-of-the-art clinical study has been conducted to address the question as to whether switching to lower tar cigarettes reduces exposure to smoke constituents in humans. Methods. Randomized, controlled, forced switching study in 225 adult smokers of full flavor Marlboro (MFF) cigarettes for 8 days with a 24-week follow-up. Subjects smoked MFF (a 15-mg Federal Trade Commission (FTC) tar cigarette) at baseline and were randomized to smoke 11-mg Marlboro Lights (ML) or 6-mg Marlboro Ultra Lights (MUL) cigarettes. Biomarkers of exposure to nicotine, 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), pyrene, CO, benzene, acrolein, and mutagenic substances were measured. Results. In the short-term phase, switching from MFF to ML showed statistically significant decreases in nicotine exposure (-13%) and non-significant increases in CO exposure (+6%), while switching from MFF to MUL showed statistically significant decreases in nicotine (-27%) and CO (-13%) exposure. Both nicotine and CO biomarkers trended similarly in the 24-week follow-up as in the short-term phase. The other biomarkers of cigarette smoke constituents followed the same trend as nicotine at the end of the 24-week follow-up. Conclusions. Switching smokers to lower FTC tar yield cigarettes, on average, reduces nicotine and other biomarkers considered surrogates of tar exposure.

CSP deposition to the alveolar region of the lung: implications of cigarette design

Ventilated cigarettes were designed to reduce the levels of smoke under machine testing conditions; however, smokers alter their smoking pattern to compensate for the reduction in yields. A relative shift in incidence of lung cancer from the more central lung airways to the alveolar region has also been associated with ventilated cigarette use. Validated mathematical models indicate that particle deposition patterns in the lung depend on particle size and inhalation behavior, including inhalation volume, flow rate, and breath-hold time. This article finds that most mathematical models underpredict total cigarette smoke particulate (CSP) deposition in the lung, likely because they do not account for coagulation, hygroscopicity, and cloud dynamics, which may increase the effective particle diameter of CSP reaching the lung tissue. The models that include these processes indicate that puff volume would be unlikely to affect particle deposition in the lung, but puff time, inhalation depth, breath-hold time, and exhalation time may affect total deposition. Most compensation appears to occur through a combination of increased puff volume and puff flow, with possible increases in inhalation depth and breath-hold time. The complex interaction between the extent of cigarette ventilation, which can affect puffing/inhalation behavior, CSP concentration, and CSP size with CSP dose to the alveolar versus more central lung airways is described. Deposition efficiency in the alveoli could plausibly be increased through compensation, but it is still unclear whether compensation could sufficiently alter patterns of CSP deposition in the lung to elicit a shift in lung cancer sites.

Do reductions in the tar and nicotine yields of cigarettes help to explain recent reductions in lung cancer rates in young men and women in the United States?

Between 1985 and 2000, lung cancer rates in U.S. men and women aged 35-54 yr have declined. To investigate whether these declines can adequately be explained by changes in smoking prevalence, consumption, and duration, or if changes in tar and nicotine yields also contributed, two model-fitting approaches were used. Both approaches used individual person National Health Interview Survey data on smoking prevalence, age of starting and time of quitting, and national estimates of consumption per smoker and yields. Both approaches compared observed rates (by sex and age) relative to 1985, with those predicted after successively including various smoking variables into the model, making varying allowance for compensation for reduced yield. Approach A was simpler, based on mean smoking statistics estimated separately for current and former smokers. Approach B used the multistage model and individual smoking histories to estimate risk. Both approaches showed observed declines in risk were (except for men aged 35-39 yr) clearly greater than predicted based only on prevalence, consumption, and duration. Including yield generally improved the fit. At younger ages, models assuming substantial compensation (consistent with evidence from studies relating nicotine yield and intake) fitted well, but at age 50-54 yr in both sexes and age 45-49 yr in women, the decline was better fitted by models assuming little compensation. The conclusions were not sensitive to the precise parameter values assumed in the modeling. Interpretation is not straightforward, but the findings suggest declines in yields have contributed to the recent declines in rates in young U.S. men and women.

Similar uptake of lung carcinogens by smokers of regular, light, and ultralight cigarettes

Cigarette design has changed markedly over the past 60 years and sales-weighed levels of tar and nicotine have decreased. Currently, cigarettes are classified as regular (>14.5 mg tar), light (>6.5-14.5 mg tar), and ultralight (< or =6.5 mg tar), based on a Federal Trade Commission-specified machine-smoking protocol. Epidemiologic studies suggest that there is no difference in lung cancer risk among people who smoke light or ultralight cigarettes compared with regular cigarettes, but the uptake of lung carcinogens in smokers of these types of cigarettes has never been reported. We recruited 175 smokers, who filled out a tobacco use questionnaire in which their current brand was identified as regular, light, or ultralight. Urine samples were collected and analyzed for 1-hydroxypyrene (1-HOP), total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL plus its glucuronides) and total cotinine (cotinine plus its glucuronides). 1-HOP and total NNAL are biomarkers of uptake of polycyclic aromatic hydrocarbons and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, lung carcinogens in cigarette smoke. Total cotinine is a biomarker of nicotine uptake. There were no statistically significant differences in urinary levels of 1-HOP, total NNAL, and total cotinine in smokers of regular, light, and ultralight cigarettes, whether the results were expressed per mg urinary creatinine, per mL of urine, or per mg creatinine divided by cigarettes per day. Levels of machine measured tar were available for the cigarettes smoked by 149 of the subjects. There was no correlation between levels of tar and any of the biomarkers. These results indicate that lung carcinogen and nicotine uptake, as measured by urinary 1-HOP, total NNAL, and total cotinine is the same in smokers of regular, light, and ultralight cigarettes. The results are consistent with epidemiologic studies that show no difference in lung cancer risk in smokers of these cigarettes.

Short-term exposure evaluation of adult smokers switching from conventional to first-generation electrically heated cigarettes during controlled smoking

This randomized, controlled study in 110 male and female adult smokers evaluated biomarkers of tobacco smoke exposure (carbon monoxide [CO], carboxyhemoglobin [CO-Hb], nicotine, urine mutagenicity) under controlled smoking conditions when adult smokers of 1 conventional cigarette brand (CC1) were switched to an electrically heated cigarette smoking system (EHCSS) or a low-tar conventional cigarette (CC2). Baseline exposure was determined while all subjects smoked CC1. Subjects then were stratified for gender and cigarette consumption and randomized to 1 of 5 groups-EHCSS1, EHCSS2, CC1, CC2, or no smoking-and monitored for 8 days. Compared to baseline, biomarkers of exposure on day 8 decreased 53% to 93% (P < .0001) for EHCSS groups and 18% to 39% (P < .02) for CC2. Environmental tobacco smoke arising from the smoking activities of the different study groups was measured in the air of a separate smoking room over 1-hour periods. Concentrations of respirable suspended particulates in both EHCSS groups were about 90% lower than in the CC1 and CC2 groups, similar to the 95% reduction in the no-smoking group. CO was undetectable in the EHCSS and no-smoking groups. Results from this short-term clinical study indicate that switching from a conventional cigarette to a first-generation EHCSS reduces the generation of environmental tobacco smoke and can reduce the exposure to the measured, potentially harmful constituents in tobacco smoke if smokers do not compensate by numbers of cigarettes. The study design was found to be suitable for the evaluation of the exposure of adult smokers to the measured smoke constituents and to allow the differentiation of different cigarette designs.

[What perception have smokers of nicotine and tar yields of cigarettes?]

INTRODUCTION

Advertising information on cigarette package participate to the reduction of health risks from smoking. Impact on smokers has been poorly studied. This study intended to determine the smoker perception of nicotine and tar yields of cigarettes.

METHODS

Consulting in an outpatient smoking cessation clinic, 171 smokers answered freely and spontaneously to a questionnaire evaluating their perception of nicotine and tar yields, cigarette consumption (number and brand), nicotine dependence. Simultaneously, biological tobacco markers were measured.

RESULTS

The number of cigarettes, nicotine dependence and specific tobacco markers were not significantly different according to the cigarette type: "full savour", "light" or "ultra light". Women smoked less than men and 54% preferred "light" cigarettes versus 37% of men. These smokers were entering a tobacco cessation program, it was assumed they had lead a prior reflection about their smoking habits. Only 8% of them gave the correct values of nicotine and tar yields and 14% gave approximate values. Tar levels were highly underestimated.

CONCLUSIONS

This study shows that smokers have actually no interest for nicotine and tar yields. As the new decree which modifies manufacture's obligation concerning the legal mentions, is applicable in January 2004 in France; our conclusion may change in the future.

Acute wood or coal exposure with carbon monoxide intoxication induces sister chromatid exchange

OBJECTIVE

The object of this study was to investigate the genotoxic effect of acute overexposure to combustion products originating from coal or wood stoves in patients presenting with acute carbon monoxide intoxication.

STUDY DESIGN

In a prospective study, we analyzed the frequency of sister chromatid exchange and the carboxyhemoglobin concentration in 20 consecutive patients without a history of smoking or drug use who had been treated in the Emergency Care Unit of Istanbul Medical Faculty due to acute carbon monoxide intoxication. All of these cases were domestic accidents due to dysfunctioning coal or wood stoves. The results were compared with a control group of 20 nonsmoking, nondrug-using healthy individuals matched for age, sex, and absence of other chemical exposure.

RESULTS

The mean sister chromatid exchange frequency per metaphase was significantly higher in the study group compared to the control group: 8.11 +/- 2.39 vs. 6.33 +/- 1.60 (p = 0.008). We found that there was no positive correlation between the blood carboxyhemoglobin concentration and sister chromatid exchange frequency.

CONCLUSIONS

These results suggest that acute exposure to combustion products of wood or coal is genotoxic to DNA. Potential causes of genotoxicity include known mutagenic compounds present in coal or wood smoke and ash, oxygen radicals formed during combustion, as well as hypoxic and reperfusion injury mechanisms initiated by carbon monoxide intoxication. Additional studies on separate carbon monoxide exposure from smoke and ash are needed to understand individual genotoxic contributions and mechanisms.

The effect of the trolox equivalent antioxidant capacity (TEAC) in plasma on the formation of 4-aminobiphenylhaemoglobin adducts in smokers

Smokers are exposed to a number of carcinogenic compounds including aromatic amines such as 4-aminobiphenyl. Antioxidants are thought to be involved in the defence against the damaging effect of such carcinogens. Recently it has been shown that plasma antioxidant status in smokers is diminished compared with non-smokers. In this study we investigated in 40 smokers whether the trolox equivalent antioxidant capacity (TEAC) in plasma could be quantitatively related to exposure to cigarette smoke. The biomarkers 4-aminobiphenylhaemoglobin (4-ABP-Hb) adduct and cotinine were determined as indices of cigarette smoke exposure. A correlation between 4-ABP-Hb adduct levels and plasma cotinine levels was found for the whole population studied, who smoked 4-70 cigarettes per day (n = 40, r(2) = 0.12, p = 0.03). A significant inverse relationship was found between TEAC and 4-ABP-Hb levels (n = 40, r(2) = 0.17, p = 0.008). Multiple regression analysis showed a strong relationship between 4-ABP-Hb levels and plasma TEAC and cotinine levels (n = 40, r(2) =0.29, p = 0.002). These findings provide strong evidence that the 4- ABP-Hb adduct represents a valuable biomarker of (internal) exposure to tobacco smoke, and also that the formation of this marker is dependent on the plasma antioxidant status. The multiple regression analysis results show that the measure of effect (4-ABP-Hb adduct formation) is largely determined by dose (cotinine) and protection (TEAC).

Cigarette nicotine yields and nicotine intake among Japanese male workers

OBJECTIVES

To analyse brand nicotine yield including "ultra low" brands (that is, cigarettes yielding less-than-or-equal 0.1 mg of nicotine by Federal Trade Commission (FTC) methods) in relation to nicotine intake (urinary nicotine, cotinine and trans-3'-hydroxycotinine) among 246 Japanese male smokers.

DESIGN

Cross sectional study.

SETTING

Two companies in Osaka, Japan.

SUBJECTS

130 Japanese male workers selected randomly during their annual regular health check up and 116 Japanese male volunteers taking part in a smoking cessation programme.

MAIN OUTCOME MEASUREMENTS

Subjects answered a questionnaire about smoking habits. Following the interview, each participant was asked to smoke his own cigarette and, after extinguishing it, to blow expired air into an apparatus for measuring carbon monoxide concentration. Urine was also collected for the assays of nicotine metabolites.

RESULTS

We found wide variation in urinary nicotine metabolite concentrations at any given nicotine yield. Based on one way analysis of variance (ANOVA), the urinary nicotine metabolite concentrations of ultra low yield cigarette smokers were significantly lower compared to smokers of high (p = 0.002) and medium yield cigarettes (p = 0.017). On the other hand, the estimated nicotine intake per ultra low yield cigarette smoked (0.59 mg) was much higher than the 0.1 mg indicated by machine.

CONCLUSIONS

In this study of Japanese male smokers, actual levels of nicotine intake bore little relation to advertised nicotine yield levels. Our study reinforces the need to warn consumers of inappropriate advertisements of nicotine yields, especially low yield brands.

Improved outcome with organs from carbon monoxide poisoned donors for intrathoracic transplantation

BACKGROUND

The success of intrathoracic organ transplantation has lead to a growing imbalance between the demand and supply of donor organs. Accordingly, there has been an expansion in the use of organs from nonconventional donors such as those who died from carbon monoxide poisoning. We describe our experience with 7 patients who were transplanted using organs after fatal carbon monoxide poisoning.

METHODS

A retrospective study of the 1,312 intrathoracic organ transplants between January 1979 and February 2000 was completed. Seven of these transplants (0.5%) were fulfilled with organs retrieved from donors after fatal carbon monoxide poisoning. There were six heart transplants and one single lung transplant. The history of carbon monoxide inhalation was obtained in all of these donors.

RESULTS

Five of 6 patients with heart transplant are alive and well with survival ranging from 68 to 1,879 days (mean, 969 +/- 823 days). One patient (a 29-year-old male) died 12 hours posttransplant caused by donor organ failure. The patient who had a right single lung transplant did well initially after the transplant, but died after 8 months caused by Pneumocystis carinii pneumonia. All those recipients who were transplanted from carbon monoxide poisoned donors and ventilated for more than 36 hours, survived for more than 30 days. Moreover, these donors were assessed and optimized by the Papworth donor management protocol.

CONCLUSIONS

Carbon monoxide poisoned organs can be considered for intrathoracic transplantation. In view of the significant risk of donor organ failure, a cautious approach is still warranted. Ideally, the donor should be hemodynamically stable for at least 36 hours from the time of poisoning and on minimal support. A formal approach of invasive monitoring and active management further improves the chances of successful outcome.