Assessment of the Exposure to Aromatic Amines in Users of Various Tobacco/Nicotine Products.

Aromatic amines such as ortho-toluidine (o-Tol), 2-aminonaphthalene (2-AN), and 4-aminobiphenyl (4-ABP) are human bladder carcinogens and occur at various workplaces, in ambient air, in food products, as well as in tobacco smoke. In a clinical study comprising a period of 74 h under confinement, we investigated the exposure to these three aromatic amines as well as to 3-aminobiphenyl (3-ABP) by measuring them in urine of habitual users of combustible cigarettes (CCs), electronic cigarettes (ECs), heated tobacco products (HTPs), oral tobacco (OT), and nicotine replacement therapy products (NRTs). Non-users (NU) of any tobacco/nicotine products served as (negative) control group. Smokers (CC) exhibited the highest levels for all four aromatic amines measured, significantly elevated compared to NU and non-CC users. Urinary levels in users of EC, HTP, NRT (mostly nicotine gum), and OT (mostly snus) were not significantly different from those in NU. Users of HTP showed slightly elevated urinary excretion levels of o-Tol, 3-ABP, and 4-ABP compared to some other non-CC groups. Dose markers such as daily consumption, urinary nicotine equivalents (Nequ), and plasma cotinine (CotP) were found to be consistently and significantly correlated with the excretion of aromatic amines for smokers (CC) only. Excretion levels of 3- and 4-ABP in smokers were significantly lower in the urine collected overnight compared to that collected during the day, which is just the opposite of what we observed for other biomarkers in this study. The possible reason for this observation is discussed. In conclusion, in contrast to smoking of CCs, the use of ECs, HTPs, nicotine gum, and oral tobacco was not observed to be associated with significant exposure to the aromatic amines o-Tol, 2-AN, 3-ABP, and 4-ABP. The observed slight increase in o-Tol, 3-ABP, and 4-ABP excretions in HTP users has to be verified in larger studies.

Urinary excretion of phenolic polycyclic aromatic hydrocarbons (OH-PAH) in nonsmokers and in smokers of cigarettes with different ISO tar yields.

Polycyclic aromatic hydrocarbons (PAH) are products of the incomplete combustion of organic materials, and they occur ubiquitously in the environment. They are also present in tobacco smoke. Some PAH have been classified as carcinogens; therefore, it is important to develop and assess suitable biomarkers for PAH exposure. A high-performance liquid chromatographic method with fluorescence detection was developed to determine 1- and 2-hydroxynaphthalene (1- and 2-OH-Nap), 2-hydroxyfluorene (2-OH-Flu), 2-/3-hydroxyphenanthrene (2-/3-OH-Phe), 1-/9-hydroxyphenanthrene (1-/9-OH-Phe), and 1-hydroxypyrene (1-OH-Pyr) in human urine. The method is sensitive (LOQ ranging from 0.01 ng/mL for 1-OH-Pyr to 1 ng/mL for the naphthols), precise (interday precision ranging from 1.4 to 6.9%), and accurate (97-106%). The method was applied to 108 urine samples from 25 nonsmokers and 83 smokers. Smokers excreted significantly higher amounts of 1-OH-Nap (16.1 vs. 2.9 microg/24 h), 2-OH-Nap (20.9 vs. 9.7 microg/24 h), 2-OH-Flu (1.87 vs. 0.75 microg/24 h), 2-/3-OH-Phe (0.73 vs. 0.50 microg/24 h), 1-/9-OH-Phe (0.66 vs. 0.35 microg/24 h), and 1-OH-Pyr (0.36 vs. 0.20 microg/24 h) compared to nonsmokers. In conclusion, the method is suitable for discriminating PAH exposure between different ISO tar yield cigarette smokers, and it may be applicable in evaluating future potential reduced exposure tobacco products.

Comparison of environmental tobacco smoke (ETS) concentrations generated by an electrically heated cigarette smoking system and a conventional cigarette.

Smoking conventional lit-end cigarettes results in exposure of nonsmokers to potentially harmful cigarette smoke constituents present in environmental tobacco smoke (ETS) generated by sidestream smoke emissions and exhaled mainstream smoke. ETS constituent concentrations generated by a conventional lit-end cigarette and a newly developed electrically heated cigarette smoking system (EHCSS) that produces only mainstream smoke and no sidestream smoke emissions were investigated in simulated "office" and "hospitality" environments with different levels of baseline indoor air quality. Smoking the EHCSS (International Organisation for Standardization yields: 5 mg tar, 0.3 mg nicotine, and 0.6 mg carbon monoxide) in simulated indoor environments resulted in significant reductions in ETS constituent concentrations compared to when smoking a representative lit-end cigarette (Marlboro: 6 mg tar, 0.5 mg nicotine, and 7 mg carbon monoxide). In direct comparisons, 24 of 29 measured smoke constituents (83%) showed mean reductions of greater than 90%, and 5 smoke constituents (17%) showed mean reductions between 80% and 90%. Gas-vapor phase ETS markers (nicotine and 3-ethenylpyridine) were reduced by an average of 97% (range 94-99%). Total respirable suspended particles, determined by online particle measurements and as gravimetric respirable suspended particles, were reduced by 90% (range 82-100%). The mean and standard deviation of the reduction of all constituents was 94 +/- 4%, indicating that smoking the new EHCSS in simulated "office" and "hospitality" indoor environments resulted in substantial reductions of ETS constituents in indoor air.

Relationship between machine-derived smoke yields and biomarkers in cigarette smokers in Germany.

In order to determine whether smokers of cigarettes in the contemporary yield ranges of the German market (0.1-1.0mg nicotine, 1-10mg tar) differ in their actual exposure to various smoke constituents, we performed a field study with 274 smokers and 100 non-smokers. The following biomarkers were determined: In 24-h urine: Nicotine equivalents (molar sum of nicotine, cotinine, trans-3'-hydroxycotinine and their respective glucuronides), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL, metabolite of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, NNK), 3-hydroxypropylmercapturic acid (metabolite of acrolein), trans,trans-muconic acid, S-phenylmercapturic acid (metabolites of benzene), 1-hydroxypyrene (metabolite of pyrene); in saliva: Cotinine and trans-3'-hydroxycotinine; in exhaled air: Carbon monoxide; in blood: Methyl-, hydroxyethyl-, cyanoethyl- (biomarker of acrylonitrile) and carbamoylethylvaline (biomarker of acrylamide) hemoglobin adducts. All biomarkers were found to be significantly higher in smokers compared to non-smokers and showed strong correlations with the daily cigarette consumption. Biomarker levels and per cigarette increases in smokers were at most weakly related to the machine-derived smoke yields. It is concluded that machine-derived yields of cigarettes from the contemporary German cigarette market have little or no impact on the actual smoking-related exposure determined by suitable biomarkers.

Determination of three carcinogenic aromatic amines in urine of smokers and nonsmokers.

Aromatic amines (arylamines) such as o-toluidine, 2-aminonaphthalene, and 4-aminobiphenyl occur in the environment and are constituents of tobacco smoke. Human exposure to these aromatic amines has long been associated with an elevated risk of bladder cancer. A validated, specific, and sensitive method for measuring o-toluidine, 2-aminonaphthalene, and 4-aminobiphenyl in cigarette smokers and nonsmokers was developed. The method uses acid hydrolysis of the arylamine conjugates in urine, extraction with n-hexane, derivatization with pentafluoropropionic anhydride, and subsequent analysis with gas chromatography combined with mass spectrometry using negative ion chemical ionization. The limits of detection were 4 ng/L for o-toluidine and 1 ng/L for 2-aminonaphthalene and 4-aminobiphenyl. Smokers (N = 10) excreted significantly higher amounts of o-toluidine (204 versus 104 ng/24 h), 2-aminonaphthalene (20.8 versus 10.7 ng/24 h), and 4-aminobiphenyl (15.3 versus 9.6 ng/24 h) than nonsmokers (N = 10). Urinary arylamine excretion in smokers was associated with the extent of smoking as assessed by daily cigarette consumption, urinary excretion of nicotine equivalents (nicotine plus its five major metabolites), cotinine in saliva, and carbon monoxide in exhaled breath. All nonsmokers investigated had quantifiable amounts of o-toluidine, 2-aminonaphthalene, and 4-aminobiphenyl in their urine, confirming that other environmental sources of exposure to these compounds also occur. In conclusion, the analytical method is suitable for measuring short-term exposure to arylamines in urine of non-occupationally exposed smokers and nonsmokers.

Influence of smoking charcoal filter tipped cigarettes on various biomarkers of exposure.

Charcoal (CC) filters of cigarettes are known to significantly reduce a series of volatile constituents in mainstream smoke, including reactive alpha,beta-unsaturated aldehydes such as acrolein and crotonaldehyde. We performed a randomized, crossover, 2-wk brand-switching study with 39 smokers. Twenty of the subjects smoked cellulose acetate (CA) filter tipped cigarettes during wk 1 of the study; the remaining 19 subjects smoked CC filter tipped cigarettes during wk 1. In wk 2, the subjects switched to the corresponding brand with the other filter type, with similar smoking machine-derived tar and nicotine yields. Daily cigarette consumption, carbon monoxide in exhaled breath, salivary cotinine, and urinary nicotine equivalents (molar sum of nicotine plus five major metabolites) did not change significantly when switching to the cigarettes with the other filter type. Urinary excretion rates of 3-hydroxy-1-methylpropylmercapturic acid (metabolite of crotonaldehyde), monohydroxybutenylmercapturic acid (metabolite of 1,3-butadiene), and S-phenylmercapturic acid (metabolite of benzene) were significantly lower when smoking CC compared to CA filter tipped cigarettes. The reduction in amount of 3-hydroxypropylmercapturic acid (metabolite of acrolein) was of borderline significance. Other mercapturic acids and thioethers (the latter is a summary parameter that indicates the exposure to electrophilic compounds) were not or were only slightly reduced upon smoking CC filter tipped cigarettes. We conclude that smoking CC filter tipped cigarettes does not change the uptake of carbon monoxide and nicotine when compared to CA filter tipped cigarettes with similar tar and nicotine yields, but significantly reduces the exposure to toxicologically relevant smoke constituents such as acrolein, crotonaldehyde, 1,3-butadiene, and benzene.

Urinary mercapturic acids and a hemoglobin adduct for the dosimetry of acrylamide exposure in smokers and nonsmokers.

Acrylamide, used in the manufacture of polyacrylamide and grouting agents, is also present in the diet and tobacco smoke. It is a neurotoxin and a probable human carcinogen. Analytical methods were established to determine the mercapturic acids of acrylamide (N-acetyl-S-(2-carbamoylethyl)-L-cysteine, AAMA) and its metabolite glycidamide (N-(R/S)-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine, GAMA) by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS), as well as the N-terminal valine adduct of acrylamide (N-2-carbamoylethylvaline, AAVal) released by N-alkyl Edman degradation of hemoglobin by gas chromatography-mass spectrometry (GC-MS). Twenty-four-hour urine samples from 60 smokers and 60 nonsmokers were analyzed for AAMA and GAMA, and blood samples were analyzed for AAVal. Smokers excreted 2.5-fold higher amounts of AAMA and 1.7-fold higher amounts of GAMA in their urine and had 3-fold higher levels of AAVal in their blood. All three biomarkers of acrylamide exposure were strongly correlated with the smoking dose as determined by the daily cigarette consumption, nicotine equivalents (the molar sum of nicotine, cotinine, trans-3'-hydroxycotinine, and their respective glucuronides) in urine, salivary cotinine, and carbon monoxide in expired breath. In nonsmokers, a weak but significant correlation between AAMA and the estimated dietary intake of acrylamide was found. It is concluded that all three biomarkers of acrylamide are suitable for the determination of exposure in both smokers and nonsmokers.

Determinants of children's exposure to environmental tobacco smoke (ETS): a study in Southern Germany.

Maternal smoking has been repeatedly found to be the most important determinant of children's exposure to environmental tobacco smoke (ETS). Here, we further investigated predictors for the urinary cotinine/creatinine ratio (CCR, ng/mg) in 1220 preschool children for the year 1996. Children from smoking homes (35.1%) had significantly higher CCR than children from nonsmoking homes (mean: 55.5 vs. 14.9 ng/mg). The level of education of the parents was a strong predictor for CCRs even after adjusting for number of cigarettes smoked, maternal smoking and dwelling space. Additionally, dwelling space was inversely related to children's urinary cotinine level. The CCR- levels in children investigated in 1996 and 1998 were significantly correlated (Pearson's r=0.67). The parents of 806 children agreed for a visit to their homes. In 79 of the 536 (14.7%) of the self-reported, nonsmoking households, smoking was admitted during the visit. The mean urinary CCR of these children was 25.2 ng/mg. We conclude that in addition to parental smoking behaviour, other variables such as dwelling space and social and educational status predict the children's exposure to ETS. Our data also revealed that a considerable percentage of parents denied the ETS exposure of their children at home.