Formation of carcinogens indoors by surface-mediated reactions of nicotine with nitrous acid, leading to potential thirdhand smoke hazards

Thirdhand smoke beliefs of parents

OBJECTIVE

To determine if the belief that thirdhand smoke is harmful to children is associated with smoking parents' attitudes, home or car smoking policies, and quitting behaviors.

METHODS

Data from a national randomized controlled trial, Clinical Effort Against Secondhand Smoke Exposure, assessed thirdhand smoke beliefs of 1947 smoking parents in an exit survey after a pediatric office visit in 10 intervention and 10 control practices. Twelve-month follow-up data were collected from 1355 parents. Multivariable logistic regression determined whether belief that thirdhand smoke harms the health of children is independently associated with parental behaviors and attitudes 12 months later. A χ(2) test assessed whether parents who disagreed that thirdhand smoke is harmful were more likely to make a quit attempt if they later believed that thirdhand smoke is harmful.

RESULTS

Belief at the exit survey that thirdhand smoke is harmful was independently associated with having a strictly enforced smoke-free home policy (adjusted odds ratio: 2.05; 95% CI: 1.37-3.05) and car policy (adjusted odds ratio: 1.69; 95% CI: 1.04-2.74) at the 12-month follow-up. A significantly higher percentage (71% vs 50%) of parents who did not hold the thirdhand smoke harm belief at baseline made at least 1 quit attempt if they agreed that thirdhand smoke is harmful at the 12-month follow-up (P = .02).

CONCLUSIONS

Thirdhand smoke harm belief was associated with a strictly enforced smoke-free home and car and attempts to quit smoking. Sensitizing parents to thirdhand smoke risk could facilitate beneficial tobacco control outcomes.

Thirdhand cigarette smoke in an experimental chamber: evidence of surface deposition of nicotine, nitrosamines and polycyclic aromatic hydrocarbons and de novo formation of NNK

BACKGROUND

A growing body of evidence shows that secondhand cigarette smoke undergoes numerous chemical changes after it is released into the air: it can adsorb to indoor surfaces, desorb back into the air and undergo chemical changes as it ages.

OBJECTIVES

To test the effects of aging on the concentration of polycyclic aromatic hydrocarbons (PAHs), nicotine and tobacco-specific nitrosamines in cigarette smoke.

METHODS

We generated sidestream and mainstream cigarette smoke with a smoking machine, diluted it with conditioned filtered air, and passed it through a 6 m(3) flow reactor with air exchange rates that matched normal residential air exchange rates. We tested the effects of 60 min aging on the concentration of 16 PAHs, nicotine, cotinine and tobacco-specific nitrosamines. We also measured sorption and deposition of nicotine, cotinine and tobacco-specific nitrosamines on materials placed within the flow reactor.

RESULTS

We observed mass losses of 62% for PAHs, 72%, for nicotine, 79% for N-nitrosonornicotine and 80% for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Extraction of cotton cloth exposed to smoke yielded nicotine and NNK. The ratio of NNK:nicotine on the exposed cloth was 10-fold higher than that in aerosol samples.

CONCLUSIONS

Our data suggest that the majority of the PAHs, nicotine, cotinine and tobacco-specific nitrosamines that are released during smoking in homes and public places deposit on room surfaces. These data give an estimate of the potential for accumulation of carcinogens in thirdhand cigarette smoke. Exposure to PAHs and tobacco-specific nitrosamines, through dermal absorption and inhalation of contaminated dust, may contribute to smoking-attributable morbidity and mortality.

Cigarette smoke toxins deposited on surfaces: implications for human health

Cigarette smoking remains a significant health threat for smokers and nonsmokers alike. Secondhand smoke (SHS) is intrinsically more toxic than directly inhaled smoke. Recently, a new threat has been discovered - Thirdhand smoke (THS) - the accumulation of SHS on surfaces that ages with time, becoming progressively more toxic. THS is a potential health threat to children, spouses of smokers and workers in environments where smoking is or has been allowed. The goal of this study is to investigate the effects of THS on liver, lung, skin healing, and behavior, using an animal model exposed to THS under conditions that mimic exposure of humans. THS-exposed mice show alterations in multiple organ systems and excrete levels of NNAL (a tobacco-specific carcinogen biomarker) similar to those found in children exposed to SHS (and consequently to THS). In liver, THS leads to increased lipid levels and non-alcoholic fatty liver disease, a precursor to cirrhosis and cancer and a potential contributor to cardiovascular disease. In lung, THS stimulates excess collagen production and high levels of inflammatory cytokines, suggesting propensity for fibrosis with implications for inflammation-induced diseases such as chronic obstructive pulmonary disease and asthma. In wounded skin, healing in THS-exposed mice has many characteristics of the poor healing of surgical incisions observed in human smokers. Lastly, behavioral tests show that THS-exposed mice become hyperactive. The latter data, combined with emerging associated behavioral problems in children exposed to SHS/THS, suggest that, with prolonged exposure, they may be at significant risk for developing more severe neurological disorders. These results provide a basis for studies on the toxic effects of THS in humans and inform potential regulatory policies to prevent involuntary exposure to THS.

Prevalence of smoke-free car and home rules in Maine before and after passage of a smoke-free vehicle law, 2007-2010

INTRODUCTION

This is the first study to examine the prevalence of self-reported smoke-free rules for private cars and homes before and after the passage of a smoke-free vehicle law.

METHODS

Data were examined for 13,461 Maine adults aged 18 or older who participated in the Behavioral Risk Factor Surveillance System, a state-based telephone survey covering health topics. Self-reported smoke-free car and home rules, smoking behavior, and demographic variables of age, sex, education, income, and children in household were analyzed for prevalence before and after the state's smoke-free vehicle law was passed.

RESULTS

Prevalence of smoke-free car and home rules was significantly higher after Maine's smoke-free vehicle law was passed in the state (P = .004 for car rules and P = .009 for home rules). Variations in smoking rules differed by smoking and demographic variables. People with household incomes of less than $20,000 saw an increase of 14.3% in smoke-free car rules; overall, those with annual incomes of less than $20,000 and those with less than a high school education reported a lower prevalence of smoke-free car rules both before and after the law was passed than did people with higher incomes and higher education levels. The prevalence of smoke-free home rules after the law was implemented was higher among those with 4 or more years of college education than among those with lower levels of education (P = .02).

CONCLUSION

The prevalence of smoke-free car and home rules among Maine adults was significantly higher after the passage of a statewide smoke-free vehicle law. This apparent change in smoke-free rule prevalence may be indicative of changing social norms related to the unacceptability of secondhand smoke exposure.

Thirdhand tobacco smoke: a tobacco-specific lung carcinogen on surfaces in smokers' homes

INTRODUCTION

Thirdhand tobacco smoke consists of substances remaining on the surfaces or in the dust of areas where people have smoked. While previous studies have demonstrated the presence of nicotine and various other constituents of tobacco smoke on surfaces in smokers' homes, none has investigated the presence of tobacco-specific carcinogens.

METHODS

We used liquid chromatography-tandem mass spectrometry to analyze surface dust samples from both the homes of smokers and nonsmokers for the powerful tobacco-specific lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK).

RESULTS

We positively identified NNK on surfaces in 33 of 37 smokers' homes (700±788 pg/100cm(2) [range, not detected-3,500 pg/100cm(2)]), but only in 3 of 19 nonsmokers' homes (235±176 pg/100cm(2) in the homes where NNK was detected [range, not detected-435 pg/100cm(2)]). The differences in occurrence and levels of NNK in the homes of smokers and nonsmokers were significant (p < .0001).

CONCLUSIONS

The powerful tobacco-specific lung carcinogen NNK is present on surfaces in most homes occupied by smokers. Potential renters or buyers of apartments or homes should be notified if previous residents were smokers in order to avoid unnecessary exposure of their families to a potent lung carcinogen.

Levels of nicotine in dust from homes of smokeless tobacco users

BACKGROUND

Smokeless tobacco products, such as chewing tobacco or moist snuff, contain many of the same constituents as tobacco smoke and are also known to cause cancer; however, little attention has been paid to indirect exposure of children to tobacco constituents via parental smokeless tobacco use.

METHODS

As part of the California Childhood Leukemia Study, we collected dust samples from 6 residences occupied by smokeless tobacco users, 6 residences occupied by active smokers, and 20 tobacco-free residences. Children's potential for exposure to tobacco constituents was assessed using nicotine concentrations in vacuum dust measured by gas chromatography-mass spectrometry.

RESULTS

Median nicotine concentrations for residences with smokeless tobacco users were significantly greater than median nicotine concentrations for tobacco-free homes and similar to median nicotine concentrations in homes of active smokers. Using generalized estimating equations derived from a multivariable marginal model to adjust for a history of parental smoking, income, residence construction date, and mother's age and race/ethnicity, we found nicotine levels from homes of smokeless tobacco users to be 21-fold higher than nicotine levels from tobacco-free homes. Based on mass balance equations, we hypothesize that nicotine is transferred to floors in homes of smokeless tobacco users primarily as a constituent of tobacco that is spilled or expectorated.

CONCLUSIONS

Based on our findings, we conclude that children living with smokeless tobacco users may be exposed to nicotine and other constituents of tobacco via contact with contaminated dust and household surfaces.

Nicotelline: a proposed biomarker and environmental tracer for particulate matter derived from tobacco smoke

Particulate matter (PM) derived from tobacco smoke contains numerous toxic substances. Since the PM and gas phase of tobacco smoke may distribute differently in the environment and substances in them may have different human bioavailability, multiple tracers and biomarkers for tobacco smoke constituents are desirable. Nicotelline is a relatively nonvolatile alkaloid present in tobacco smoke, and therefore, it has the potential to be a suitable tracer and biomarker for tobacco smoke-derived PM. We describe experiments demonstrating that nicotelline is present almost entirely in the PM, in both freshly generated cigarette smoke and aged cigarette smoke. An excellent correlation between the mass of nicotelline and the mass of the PM in aged cigarette smoke was found. We also describe experiments suggesting that the main source of nicotelline in tobacco smoke is dehydrogenation of another little-studied tobacco alkaloid, anatalline, during the burning process. We show that nicotelline metabolites can be measured in the urine of smokers and that nicotelline can be measured in house dust from homes of smokers and nonsmokers. We conclude that nicotelline should be useful as a tracer and biomarker for PM derived from tobacco smoke.

Detection of secondhand cigarette smoke via nicotine using conductive polymer films

INTRODUCTION

The 2006 U.S. Surgeon General's Report found that there is no safe level of exposure to secondhand smoke (SHS). Many smokers attempt to protect others from exposure to SHS; however, it is difficult to assess effectiveness of these behavior changes. There is a need for personal monitoring devices that provide real-time SHS exposure data; at present, there is no device that measures ambient nicotine levels in real time. The development of such a sensor is the objective of this research.

METHODS

A nicotine sensing film comprising the conductive polymer polyaniline was linked with a reporting layer, recording changes in chemiresistance due to adsorption of nicotine. Experiments were carried out in a microprocessor-controlled smoking chamber using sidestream smoke from standard reference cigarettes; up to 10 cigarettes were smoked simultaneously. The exposure chamber was calibrated for total suspended particle, carbon monoxide, and nicotine concentrations.

RESULTS

We found significant real-time increases in the resistance of films upon exposure to SHS. The sensors were shown to be sensitive to the number of cigarettes consumed and ambient nicotine and demonstrated reasonable recovery between measurements. The sensors have sufficient sensitivity to detect off-gassing of nicotine or "thirdhand smoke."

CONCLUSIONS

A sensing element has been developed that can reliably detect secondhand and thirdhand tobacco smoke in real time through the adsorption of ambient nicotine vapor. The device was calibrated to the number of smoked cigarettes and to nicotine concentration. Development of integrated personal sensors to record exposure to SHS using this technology is currently underway.

Housing and child health

The connection between housing and health is well established. Physical, chemical, and biological aspects of the child's home, such as cleanliness, moisture, pests, noise, accessibility, injury risks, and other forms of housing environmental quality, all have the potential to influence multiple aspects of the health and development of children. Basic sanitation, reduced household crowding, other improvements in housing and expanded, and improved housing regulations have led to advances in children's health. For example, lead poisoning prevention policies have profoundly reduced childhood lead exposure in the United States. This and many other successes highlight the health benefits for families, particularly children, by targeting interventions that reduce or eliminate harmful exposures in the home. Additionally, parental mental health problems, food insecurity, domestic violence, and the presence of guns in children's homes all are largely experienced by children in their homes, which are not as yet considered part of the Healthy Homes agenda. There is a large movement and now a regulatory structure being put in place for healthy housing, which is becoming closely wedded with environmental health, public health, and the practice of pediatrics. The importance of homes in children's lives, history of healthy homes, asthma, and exposures to lead, carbon monoxide, secondhand/thirdhand smoke, radon, allergy triggers is discussed, as well as how changes in ambient temperature, increased humidity, poor ventilation, water quality, infectious diseases, housing structure, guns, electronic media, family structure, and domestic violence all affect children's health.

Validity of self-reported adult secondhand smoke exposure

OBJECTIVES

Exposure of adults to secondhand smoke (SHS) has immediate adverse effects on the cardiovascular system and causes coronary heart disease. The current study evaluated brief self-report screening measures for accurately identifying adult cardiology patients with clinically significant levels of SHS exposure in need of intervention.

DESIGN AND SETTING

A cross-sectional study conducted in a university-affiliated cardiology clinic and cardiology inpatient service.

PATIENTS

Participants were 118 non-smoking patients (59% male, mean age=63.6 years, SD=16.8) seeking cardiology services.

MAIN OUTCOME MEASURES

Serum cotinine levels and self-reported SHS exposure in the past 24 h and 7 days on 13 adult secondhand exposure to smoke (ASHES) items.

RESULTS

A single item assessment of SHS exposure in one's own home in the past 7 days was significantly correlated with serum cotinine levels (r=0.41, p<0.001) with sensitivity ≥75%, specificity >85% and correct classification rates >85% at cotinine cut-off points of >0.215 and >0.80 ng/mL. The item outperformed multi-item scales, an assessment of home smoking rules, and SHS exposure assessed in other residential areas, automobiles and public settings. The sample was less accurate at self-reporting lower levels of SHS exposure (cotinine 0.05-0.215 ng/mL).

CONCLUSIONS

The single item ASHES-7d Home screener is brief, assesses recent SHS exposure over a week's time, and yielded the optimal balance of sensitivity and specificity. The current findings support use of the ASHES-7d Home screener to detect SHS exposure and can be easily incorporated into assessment of other major vital signs in cardiology.

Association of maternal smoking with child cotinine levels

INTRODUCTION

Our aim was to understand the strength of association between parental smoking and child environmental tobacco smoke (ETS) exposure in order to inform the development of future tobacco control policies. ETS was measured using child cotinine levels below the active smoking threshold.

METHODS

Participants were drawn from the Avon Longitudinal Study of Parents and Children and included 3,128 participants at age 7 years and 1,868 participants at age 15 years. The primary outcome was cotinine levels of nonsmoking children, to investigate the relationship between maternal smoking and child cotinine levels. The secondary outcome was cotinine levels of all individuals to investigate the relationship between child smoking and child cotinine levels. Maternal and child smoking behavior was assessed by self-report questionnaire. We adjusted for several sociodemographic variables.

RESULTS

We found an association between maternal smoking and child cotinine at age 7 years (mean cotinine = 1.16ng/ml serum, ratio of geometric means = 3.94, 95% CI = 2.86-5.42) and at age 15 years (mean cotinine = 0.94ng/ml serum, ratio of geometric means = 5.26, 95% CI = 3.06-9.03), after adjustment for potential confounders.

CONCLUSIONS

The magnitude of this association for children whose mothers were heavy smokers was comparable with the quantity of half the levels of cotinine observed among children who were irregular (i.e., nonweekly) active smokers, and it was greater than five times higher than that seen in nonsmoking children whose mothers didn't smoke. This provides further evidence for the importance of public health interventions to reduce smoking exposure in the home.

Smoking restrictions in the homes of children with cancer

OBJECTIVES

To examine smoking restrictions in households of children with cancer and their effect on biological measures of children's secondhand smoke exposure (SHSe).

METHODS

A sample of 135 parents of nonsmoking children with cancer who lived with a smoker completed structured interviews.

RESULTS

Approximately 43% of families prohibited smoking in the home. Children living in homes that prohibited smoking had median cotinine levels that were 71% and 52% lower than did those from homes with no and partial restrictions.

CONCLUSIONS

Parents should be directed to completely ban all smoking from the home and car to best protect their children from SHSe.

Thirdhand smoke and exposure in California hotels: non-smoking rooms fail to protect non-smoking hotel guests from tobacco smoke exposure

INTRODUCTION

This study examined tobacco smoke pollution (also known as thirdhand smoke, THS) in hotels with and without complete smoking bans and investigated whether non-smoking guests staying overnight in these hotels were exposed to tobacco smoke pollutants.

METHODS

A stratified random sample of hotels with (n=10) and without (n=30) complete smoking bans was examined. Surfaces and air were analysed for tobacco smoke pollutants (ie, nicotine and 3-ethynylpyridine, 3EP). Non-smoking confederates who stayed overnight in guestrooms provided urine and finger wipe samples to determine exposure to nicotine and the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone as measured by their metabolites cotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), respectively.

FINDINGS

Compared with hotels with complete smoking bans, surface nicotine and air 3EP were elevated in non-smoking and smoking rooms of hotels that allowed smoking. Air nicotine levels in smoking rooms were significantly higher than those in non-smoking rooms of hotels with and without complete smoking bans. Hallway surfaces outside of smoking rooms also showed higher levels of nicotine than those outside of non-smoking rooms. Non-smoking confederates staying in hotels without complete smoking bans showed higher levels of finger nicotine and urine cotinine than those staying in hotels with complete smoking bans. Confederates showed significant elevations in urinary NNAL after staying in the 10 most polluted rooms.

CONCLUSIONS

Partial smoking bans in hotels do not protect non-smoking guests from exposure to tobacco smoke and tobacco-specific carcinogens. Non-smokers are advised to stay in hotels with complete smoking bans. Existing policies exempting hotels from complete smoking bans are ineffective.

An online monitoring system for atmospheric nitrous acid (HONO) based on stripping coil and ion chromatography

A new instrument for measuring atmospheric nitrous acid (HONO) was developed, consisting of a double-wall glass stripping coil sampler coupled with ion chromatography (SC-IC). SC-IC is featured by small size (50 x 35 x 25 cm) and modular construction, including three independent parts: the sampling unit, the transfer and supporting unit, and the detection unit. High collection efficiency (> 99%) was achieved with 25 micromol/L Na2CO3 as absorption solution even in the presence of highly acidic compounds. This instrument has a detection limit of 8 pptv at 15 min time resolution, with a measurement uncertainty of 7%. Potential interferences from NO(x), NO2+SO2, NO2+VOCs, HONO+O3, HNO3, peroxyacetyl nitrite (PAN) and particle nitrite were quantified in laboratory studies and were found to be insignificant under typical atmospheric conditions. Within the framework of the 3C-STAR project, inter-comparison between the SC-IC and LOPAP (long path liquid absorption photometer) was conducted at a rural site in the Pearl River Delta. Good agreement was achieved between the two instruments over three weeks. Both instruments determined a clear diurnal profile of ambient HONO concentrations from 0.1 to 2.5 ppbv. However, deviations were found for low ambient HONO concentrations (i.e. < 0.3 ppbv), which cannot be explained by previous investigated interference species. To accurately determine the HONO budget under illuminated conditions, more intercomparison of HONO measurement techniques is still needed in future studies, especially at low HONO concentrations.

Intervention to reduce secondhand smoke exposure among children with cancer: a controlled trial

OBJECTIVE

This randomized controlled trial tested the efficacy of parent-based behavioral counseling for reducing secondhand smoke exposure (SHSe) among children with cancer. It also examined predictors of smoking and SHSe outcomes.

METHODS

Participants were 135 parents or guardians of nonsmoking children with cancer, <18 years, at least 30 days postdiagnosis, and living with at least one adult smoker. Parents were randomized to either a standard care control group or an intervention consisting of six counseling sessions delivered over 3 months. Parent-reported smoking and child SHSe levels were obtained at baseline, 3, 6, 9, and 12 months. Children provided urine samples for cotinine analyses.

RESULTS

Reductions in parent-reported smoking and exposure were observed in both the intervention and control conditions. There was a significantly greater reduction in parent-reported smoking and child SHSe at 3 months for the intervention group compared with the control group. Child SHSe was significantly lower at 12 months relative to baseline in both groups. Children's cotinine levels did not show significant change over time in either group. Exposure outcomes were influenced by the number of smokers at home, smoking status of the parent participating in the trial, and the child's environment (home versus hospital) the day before the assessment.

CONCLUSIONS

Children's SHSe can be reduced by advising parents to protect their child from SHSe, combined with routine reporting of their child's exposure and cotinine testing, when delivered in the context of the pediatric cancer setting. More intensive interventions may be required to achieve greater reductions in SHSe.

Thirdhand smoke causes DNA damage in human cells

Exposure to thirdhand smoke (THS) is a newly described health risk. Evidence supports its widespread presence in indoor environments. However, its genotoxic potential, a critical aspect in risk assessment, is virtually untested. An important characteristic of THS is its ability to undergo chemical transformations during aging periods, as demonstrated in a recent study showing that sorbed nicotine reacts with the indoor pollutant nitrous acid (HONO) to form tobacco-specific nitrosamines (TSNAs) such as 4-(methylnitrosamino)-4-(3-pyridyl)butanal (NNA) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The goal of this study was to assess the genotoxicity of THS in human cell lines using two in vitro assays. THS was generated in laboratory systems that simulated short (acute)- and long (chronic)-term exposures. Analysis by liquid chromatography-tandem mass spectrometry quantified TSNAs and common tobacco alkaloids in extracts of THS that had sorbed onto cellulose substrates. Exposure of human HepG2 cells to either acute or chronic THS for 24h resulted in significant increases in DNA strand breaks in the alkaline Comet assay. Cell cultures exposed to NNA alone showed significantly higher levels of DNA damage in the same assay. NNA is absent in freshly emitted secondhand smoke, but it is the main TSNA formed in THS when nicotine reacts with HONO long after smoking takes place. The long amplicon-quantitative PCR assay quantified significantly higher levels of oxidative DNA damage in hypoxanthine phosphoribosyltransferase 1 (HPRT) and polymerase β (POLB) genes of cultured human cells exposed to chronic THS for 24h compared with untreated cells, suggesting that THS exposure is related to increased oxidative stress and could be an important contributing factor in THS-mediated toxicity. The findings of this study demonstrate for the first time that exposure to THS is genotoxic in human cell lines.

Wipe sampling for nicotine as a marker of thirdhand tobacco smoke contamination on surfaces in homes, cars, and hotels

INTRODUCTION

Secondhand smoke contains a mixture of pollutants that can persist in air, dust, and on surfaces for months or longer. This persistent residue is known as thirdhand smoke (THS). Here, we detail a simple method of wipe sampling for nicotine as a marker of accumulated THS on surfaces.

METHODS

We analyzed findings from 5 real-world studies to investigate the performance of wipe sampling for nicotine on surfaces in homes, cars, and hotels in relation to smoking behavior and smoking restrictions.

RESULTS

The intraclass correlation coefficient for side-by-side samples was 0.91 (95% CI: 0.87-0.94). Wipe sampling for nicotine reliably distinguished between private homes, private cars, rental cars, and hotels with and without smoking bans and was significantly positively correlated with other measures of tobacco smoke contamination such as air and dust nicotine. The sensitivity and specificity of possible threshold values (0.1, 1, and 10 μg/m(2)) were evaluated for distinguishing between nonsmoking and smoking environments. Sensitivity was highest at a threshold of 0.1 μg/m(2), with 74%-100% of smoker environments showing nicotine levels above threshold. Specificity was highest at a threshold of 10 μg/m(2), with 81%-100% of nonsmoker environments showing nicotine levels below threshold. The optimal threshold will depend on the desired balance of sensitivity and specificity and on the types of smoking and nonsmoking environments.

CONCLUSIONS

Surface wipe sampling for nicotine is a reliable, valid, and relatively simple collection method to quantify THS contamination on surfaces across a wide range of field settings and to distinguish between nonsmoking and smoking environments.

Occurrence of atmospheric nitrous acid in the urban area of Beijing (China)

The atmospheric concentrations of nitrous acid (HONO) have been measured during two field campaigns in the winter and summer of 2007 at Beijing (China). The results were discussed from the standpoint of temporal and diurnal variations and meteorological effects. The daily average HONO concentrations were in the range of 0.03-2.91ppb and didn't show temporal variation between the winter and summer periods. The temporal trends seemed to be largely affected by meteorological conditions. HONO concentrations showed very typical diurnal variations during intensive winter and summer periods. Nitrogen oxides were key precursors of HONO formation and the HONO/NO2 values were higher than those reported for direct emission (<1%), indicating the prevalence of secondary chemical HONO formation on direct emission during both periods. We used a pseudo steady state approach (PSS), which included homogeneous and heterogeneous reactions and direct emission, explaining on average about 83% and 48% of the observed HONO levels during the intensive winter and summer periods, respectively. The daytime unknown HONO production was on average 2.58ppbh(-1) during the summer period. The HNO3 and fine particulate NO3(-) photolysis contributed weakly as HONO source. Including these sources in the PSS calculation, we explained about 53% of the observed HONO levels. The results showed that heterogeneous JNO2 dependent processes on aerosol and ground surfaces, involving NO2 as HONO precursor, were HONO sources during the summer measurements.

A Review of Aspects of Oxidative Hair Dye Chemistry with Special Reference to N-Nitrosamine Formation

This review discusses a new aspect to the safety profile of oxidative hair dyes using data already in the public domain. These dyes contain secondary amines that are capable of forming potentially carcinogenic nitrosamine derivatives when exposed to atmospheric pollution. Numerous scientific articles confirm the existence of secondary amines in hair dyes (and their intermediates), the possibility of nitrosation by atmospheric NO_x of secondary amines to give the N-nitrosamines, and the significant safety risks on N-nitrosamines. It is believed that such nitrosamine derivatives should be investigated more fully in the interests of consumer safety.

The role of home smoking bans in limiting exposure to secondhand tobacco smoke in Hungary

Our objective was to assess how exposure to secondhand tobacco smoke occurs in Hungarian homes, particularly among non-smokers, and to examine the effectiveness of home smoking bans in eliminating exposure to secondhand smoke at home. In 2009, 2286 non-smokers and smokers aged 16-70 years, who were selected randomly from a nationally representative sample of 48 Hungarian settlements, completed paper-and-pencil self-administered questionnaires addressing tobacco-related attitudes, opinions and behaviors. Chi-square tests, one-way analysis of variance and multivariate logistic regression models were used to assess the effect of demographics, socio-economic characteristics and home smoking policies on the risk of exposure to secondhand tobacco smoke at home. Significantly higher risk of exposure was found among younger, lower educated and poorer people and among those having no or partial home smoking restrictions. There was a significant interaction between education level and home smoking policies: the effect of a smoking ban on exposure to secondhand tobacco smoke was stronger for the lower educated group than the higher educated group. The results suggest that Hungarians are making good progress in implementing home smoking bans, and that in the majority of population these bans are working. More can be done to promote the uptake of home smoking bans among poorer and less educated subpopulations.

Quantitative proteomic analysis revealed N'-nitrosonornicotine-induced down-regulation of nonmuscle myosin II and reduced cell migration in cultured human skin fibroblast cells

The association of tobacco smoke with decreased cell motility and wound healing is well documented; however, the cellular mechanisms and specific toxic tobacco constituents responsible for this effect are not well understood. Tobacco-specific N-nitrosamines (TSNAs) are among the most important classes of carcinogens found in tobacco products. The TSNA N'-nitrosonornicotine (NNN) is present at relatively high levels in tobacco and its smoke, as well as second- and third-hand smoke. To investigate the cellular pathways that are perturbed upon NNN exposure, we employed a quantitative proteomic approach, utilizing stable isotope labeling by amino acids in cell culture and mass spectrometry, to assess the NNN-induced alteration of protein expression in GM00637 human skin fibroblast cells. With this approach, we were able to quantify 2599 proteins, 191 of which displayed significantly changed expression following NNN exposure. One of the main findings from our proteomic analysis was the down-regulation of six different subunits of myosin, particularly nonmuscle myosin II heavy chain, isoforms A, B, and C. In addition, we found the altered expression of several extracellular matrix proteins and proteins involved in cellular adhesion. Together, our quantitative proteomic results suggested that NNN exposure may interfere with fibroblast motility. An in vitro scratch wound assay result supported that NNN exposure reduced the ability of dermal fibroblast to migrate into the scratched area. The results from the present study offer novel insights into the cellular mechanisms of NNN toxicity and identify NNN as a specific tobacco constituent that contributes to decreased fibroblast migration.

Thirty minute-exposure to aged cigarette smoke increases nasal congestion in nonsmokers

The aim of this study was to assess the effects of short exposures to experimentally aged cigarette smoke on the nose and upper airways. This crossover study compared the effects of 30-min exposures to (1) experimentally aged cigarette smoke at 1 mg/m³ particulate matter (PM)/14 ppm carbon monoxide (CO) and (2) conditioned filtered air on urinary metabolites of nicotine and tobacco-specific nitrosamines. Subjective nasal symptoms were assessed by questionnaire, objective nasal congestion was assessed by anterior rhinomanometry and nasal nitric oxide (NO) concentrations were determined. Experimentally aged cigarette smoke is a validated model for secondhand smoke (SHS). Twenty-six healthy nonsmokers (10 normal, 7 atopic/nonrhinitic, 7 atopic rhinitic, 2 nonatopic/rhinitic) were studied. A 30-min exposure to SHS increased nasal resistance in healthy nonsmokers. The rise in nasal resistance was most pronounced in rhinitic subjects. Significant increases were not noted when atopic subjects were considered independent of rhinitis status. Secondhand smoke exposure also elevated subjective nasal symptoms and urinary concentrations of metabolites of nicotine (cotinine and trans-3´-hydroxycotinine) and tobacco-specific nitrosamines [(4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL)] in all subgroups of subjects. Exposure-related, subjective nasal symptoms were significantly higher in rhinitic than in normal subjects. Significant changes in nasal NO concentrations were not detected. Data indicate a 30-min exposure to secondhand smoke at 1 mg/m³ PM increases subjective upper respiratory symptoms, increases urinary cotinine and NNAL, and produces objective nasal airflow obstruction in human subjects.

Tobacco smoke exposure in a sample of Boston public housing residents

BACKGROUND

There is no safe level of tobacco smoke exposure. Nonsmoking residents of public housing are at particular risk of suffering the health consequences of tobacco smoke exposure.

PURPOSE

To compare levels of tobacco smoke exposure among nonsmoking residents of the Boston Housing Authority (BHA) to previously published data from the National Health and Nutrition Examination Survey and identify factors associated with such exposure in the BHA.

METHODS

Nonsmoking adults and children from two BHA housing developments were invited to participate in a tobacco smoke exposure screening in which they completed a short survey and provided a saliva sample for cotinine analysis. Data were collected in 2011 and analyzed in 2012.

RESULTS

Of 51 eligible study participants, 88% (95% CI=76%, 95%) had detectable cotinine levels (0.15 ng/mL lower limit of detection) compared to at most 56% of residents nationally (using a more sensitive 0.05 ng/mL lower limit of detection). Geometric mean cotinine levels among study participants were 0.52 ng/mL (95% CI=0.37 ng/mL, 0.74 ng/mL) compared to at most 0.10 ng/mL nationally. Residents living in homes with strict no-smoking rules had lower cotinine levels than those without such rules (0.40 ng/mL vs 1.07 ng/mL, p=0.006).

CONCLUSIONS

Tobacco smoke exposure is substantially higher in this sample of nonsmoking BHA residents than among nonsmoking Americans nationally. A comprehensive prohibition on smoking in BHA housing units enacted in October 2012 will help protect this highly exposed group of residents and serve as a model for other housing authorities.

Pediatrician interventions and thirdhand smoke beliefs of parents

BACKGROUND

Thirdhand smoke is residual tobacco smoke contamination that remains after a cigarette is extinguished. A national study indicates that adults' belief that thirdhand smoke (THS) harms children is associated with strict household no-smoking policies. The question of whether pediatricians can influence THS beliefs has not been assessed.

PURPOSE

To identify prevalence of THS beliefs and associated factors among smoking parents, and the association of pediatrician intervention on parent belief that THS is harmful to their children.

METHODS

Exit interview data were collected from 1980 parents following a pediatric office visit. Parents' level of agreement or disagreement that THS can harm the health of babies and children was assessed. A multivariate logistic regression model was constructed to identify whether pediatricians' actions were independently associated with parental belief that THS can harm the health of babies and children. Data were collected from 2009 to 2011, and analyses were conducted in 2012.

RESULTS

Ninety-one percent of parents believed that THS can harm the health of babies and children. Fathers (AOR=0.59, 95% CI=0.42, 0.84) and parents who smoked more than ten cigarettes per day (AOR=0.63, 95% CI=0.45, 0.88) were less likely to agree with this statement. In contrast, parents who received advice (AOR=1.60, 95% CI=1.04, 2.45) to have a smokefree home or car or to quit smoking and parents who were referred (AOR=3.42, 95% CI=1.18, 9.94) to a "quitline" or other cessation program were more likely to agree that THS can be harmful.

CONCLUSIONS

Fathers and heavier smokers were less likely to believe that THS is harmful. However, pediatricians' actions to encourage smoking parents to quit or adopt smokefree home or car policies were associated with parental beliefs that THS harms children.

TRIAL REGISTRATION

This study is registered at NCT00664261.

Environmental monitoring of secondhand smoke exposure

The complex composition of secondhand smoke (SHS) provides a range of constituents that can be measured in environmental samples (air, dust and on surfaces) and therefore used to assess non-smokers' exposure to tobacco smoke. Monitoring SHS exposure (SHSe) in indoor environments provides useful information on the extent and consequences of SHSe, implementing and evaluating tobacco control programmes and behavioural interventions, and estimating overall burden of disease caused by SHSe. The most widely used markers have been vapour-phase nicotine and respirable particulate matter (PM). Numerous other environmental analytes of SHS have been measured in the air including carbon monoxide, 3-ethenylpyridine, polycyclic aromatic hydrocarbons, tobacco-specific nitrosamines, nitrogen oxides, aldehydes and volatile organic compounds, as well as nicotine in dust and on surfaces. The measurement of nicotine in the air has the advantage of reflecting the presence of tobacco smoke. While PM measurements are not as specific, they can be taken continuously, allowing for assessment of exposure and its variation over time. In general, when nicotine and PM are measured in the same setting using a common sampling period, an increase in nicotine concentration of 1 μg/m³ corresponds to an average increase of 10 μg/m³ of PM. This topic assessment presents a comprehensive summary of SHSe monitoring approaches using environmental markers and discusses the strengths and weaknesses of these methods and approaches.

Ultraviolet irradiation effects incorporation of nitrate and nitrite nitrogen into aquatic natural organic matter

One of the concerns regarding the safety and efficacy of ultraviolet radiation for treatment of drinking water and wastewater is the fate of nitrate, particularly its photolysis to nitrite. In this study, N NMR was used to establish for the first time that UV irradiation effects the incorporation of nitrate and nitrite nitrogen into aquatic natural organic matter (NOM). Irradiation of (15)N-labeled nitrate in aqueous solution with an unfiltered medium pressure mercury lamp resulted in the incorporation of nitrogen into Suwannee River NOM (SRNOM) via nitrosation and other reactions over a range of pH from approximately 3.2 to 8.0, both in the presence and absence of bicarbonate, confirming photonitrosation of the NOM. The major forms of the incorporated label include nitrosophenol, oxime/nitro, pyridine, nitrile, and amide nitrogens. Natural organic matter also catalyzed the reduction of nitrate to ammonia on irradiation. The nitrosophenol and oxime/nitro nitrogens were found to be susceptible to photodegradation on further irradiation when nitrate was removed from the system. At pH 7.5, unfiltered irradiation resulted in the incorporation of (15)N-labeled nitrite into SRNOM in the form of amide, nitrile, and pyridine nitrogen. In the presence of bicarbonate at pH 7.4, Pyrex filtered (cutoff below 290-300 nm) irradiation also effected incorporation of nitrite into SRNOM as amide nitrogen. We speculate that nitrosation of NOM from the UV irradiation of nitrate also leads to production of nitrogen gas and nitrous oxide, a process that may be termed photo-chemodenitrification. Irradiation of SRNOM alone resulted in transformation or loss of naturally abundant heterocyclic nitrogens.

Association between parental smoking behavior and children's respiratory morbidity: 5-year study in an urban city of South Korea

INTRODUCTION

After intensive tobacco control efforts in recent decades, the prevalence of active smoking has decreased. However, the hazardous effect of indirect exposure to cigarette smoke is often underestimated, especially in children. We aimed to investigate the effect of parental smoking on the respiratory morbidity of the children of parents who smoke by evaluating the relationship between parental smoking behavior and children's respiratory symptoms.

METHODS

We conducted a cross-sectional follow-up study of 31,584 children aged 6-11 in an urban community in Anyang City, Korea. The children's parents were asked about their smoking status and completed questionnaires regarding their children's symptoms related to asthma and other upper or lower respiratory illnesses. Our analysis focused on a comparison of the frequency of respiratory and ocular symptoms according to parental smoking status, whether it was non-smoking (Non-S), indirect passive smoking (third-hand smoking, THS) or direct passive smoking (second-hand smoking, SHS).

RESULTS

The children with Non-S patients were 40.9%, THS group 40.6%, and SHS group 18.5%. THS group showed lower ORs for most respiratory symptoms when compared with those of SHS group, however, THS group revealed increased ORs compared with Non-S in cough-related symptoms. There was a linear trend in frequencies of cough and sputum-related symptoms according to the degree of exposure to cigarette smoke (P < 0.05).

CONCLUSION

The prevalence of respiratory symptoms increased in children exposed to parental smoking including SHS and THS. To avoid the risk of respiratory and allergic disease by environmental tobacco smoke, absolute smoking cessation by parents is strongly recommended.

How home-smoking habits affect children: a cross-sectional study using urinary cotinine measurement in Italy

OBJECTIVES

To assess the impact of different home-smoking rules and smoking habits of cohabitant on environmental tobacco smoke (ETS) exposure of children.

METHODS

Information about 396 Italian children (5-11 years old) and cohabitants' smoking habits was collected by a questionnaire. Exposure assessment was performed by determination of urinary cotinine (u-cotinine).

RESULTS

Median u-cotinine concentrations in children significantly increased in a similar fashion as theoretical ETS exposure increase: cohabitants do not smoke (1.79 μg/g creatinine), cohabitant(s) smoker(s) never smoke at home (2.84), smoke at home only when children are out (3.90), and smoke at home even if children are in (6.02). Median u-cotinine levels of exposed children were associated to the strength of cohabitant's smoking behaviours when smoker(s) consume daily a high number of cigarettes (≥ 20) respect to light consumption (1-9) (4.52 and 3.24 μg/g creatinine).

CONCLUSIONS

The magnitude of ETS exposure in children is correlated with smoking habits and home-smoking precautions adopted by their cohabitants. Educational interventions on parents are essential to increase their awareness about ETS exposure and to teach correct behaviours to protect health of kids, especially in household environment.

Factors influencing exposure to secondhand smoke in preschool children living with smoking mothers

INTRODUCTION

The health effects on young children of exposure to secondhand smoke (SHS) are well described. Recent work suggests that over one quarter of school-aged children in Scotland are regularly exposed to SHS in the home. The study was designed to describe SHS exposure in preschool children whose mothers smoked and identify factors that influence exposure.

METHODS

Smoking mothers with at least one child aged 1-5 years were recruited to the Reducing Families' Exposure to Secondhand Smoke in the Home study. Concentrations of airborne particulate matter less than 2.5 μm in size (PM(2.5)) in the home were measured together with child's salivary cotinine. Demographics including age, accommodation type, socioeconomic status, and number of cigarettes smoked at home were recorded.

RESULTS

Data were collected from 54 homes. In 89% of the homes, concentrations of PM(2.5) exceeded health-based guidance values at some point of the day. Household PM(2.5) concentrations were highest during the evening hours of 6 p.m. to midnight. Younger children had higher salivary cotinine concentrations than older children, and the geometric mean of salivary cotinine was 2.36 ng/ml. Household smoking restrictions and maternal confidence in enforcing smoking restrictions in their own home were strongly associated with child's SHS exposure.

CONCLUSIONS

Preschool children's exposure to SHS in homes where the mother smokes is considerable. Interventions and policy development to increase parental awareness of the health effects of SHS and provide parents with the confidence to implement smoke-free households are required to reduce the SHS exposure of preschool age children.

Quantitative proteomic analysis revealed 4-(methylnitrosamino)-1-(3-pyridinyl)-1-butanone-induced up-regulation of 20S proteasome in cultured human fibroblast cells

The tobacco-specific N-nitrosamine, 4-(methylnitrosamino)-1-(3-pyridinyl)-1-butanone (NNK), is a well-known carcinogen. Although the ability of the metabolically activated form of NNK to generate DNA adducts is well established, little is known about the cellular pathways perturbed by NNK in its native state. In this study, we utilized stable isotope labeling by amino acid in cell culture (SILAC), together with mass spectrometry, to assess the perturbation of protein expression in GM00637 human skin fibroblast cells upon NNK exposure. With this approach, we were able to quantify 1412 proteins and 137 of them were with significantly altered expression following NNK exposure, including the up-regulation of all subunits of the 20S proteasome core complex. The up-regulation of the 20S core complex was also reflected by a significant increase in 20S proteasome activities in GM00637, IMR90, and MCF-7 cells upon NNK treatment. Furthermore, the β-adrenergic receptor (β-AR) antagonist propranolol could attenuate significantly the NNK-induced increase in proteasome activity in all the three cell lines, suggesting that up-regulation of the 20S proteasome may be mediated through the β-AR. Additionally, we found that NNK treatment altered the expression levels of other important proteins including mitochondrial proteins, cytoskeleton-associated proteins, and proteins involved in glycolysis and gluconeogenesis. Results from the present study provided novel insights into the cellular mechanisms targeted by NNK.

Determination of nicotine and N-nitrosamines in house dust by pressurized liquid extraction and comprehensive gas chromatography--nitrogen chemiluminiscence detection

A novel, highly selective method for the determination of nicotine, N-nitrosamines and tobacco-specific nitrosamines (TSNAs) in indoor dust samples is presented in this study. Samples were extracted by in-cell clean-up pressurized liquid extraction (PLE) that allows high extraction efficiency with moderate consumption of organic solvents. The extracts were analyzed by comprehensive gas chromatography and detected with a nitrogen chemiluminiscence detector (GC×GC-NCD) that provided enhanced selectivity and sensitivity for organic nitrogen containing compounds. Method validation showed good linearity, repeatability and reproducibility (%RSD<8%). Recovery was higher than 80% for most target compounds and limits of detection lower than 16 ng g(-1). The method was used for the determination of the nitrosamine target compounds in house dust samples from both smoking and non-smoking households. All the analytes were found in the samples, nicotine being the most abundant compound in smokers' dust and one of the most abundant in non-smokers' dust. To our knowledge this is the first time that volatile N-nitrosamines and TSNAs have been determined in indoor dust samples. The results demonstrate the presence of these highly carcinogenic compounds in house dust, with inherent human exposure through inhalation and/or involuntary ingestion of house dust.

Volatile organics off-gassed among tobacco-exposed clothing fabrics

This work evaluates the characteristics of short-term release of volatile and semi-volatile organic chemicals from clothing fabrics that are exposed to environmental tobacco smoke (ETS). Various fabrics were concurrently exposed to ETS in a controlled facility, and the chemicals off-gassed were sampled using solid phase micro-extraction coupled with GC/MS analysis. Toluene-reference concentration (TRC) was calculated for nine selected chemicals and compared. The number of chemicals identified from ETS-exposed fabrics ranged from 13 (polyester and acetate) to 32 (linen). All fabrics off-gassed formaldehyde, tetradecanoic acid and n-hexadecanoic acid, while seven out of eight fabrics emitted furfural, benzonitrile, naphthalene and decanal. Natural fibers of plant origin (cotton and linen) off-gassed higher concentrations (TRC>100 μg/l) of chemicals that have low molecular weight (~100 or less) than did natural fibers of animal origin (wool and silk) and synthetic fibers. Conversely, wool and silk off-gassed more chemicals that are of high molecular weight (>200), such as TDA (TRC>100 μg/l) and n-HDA (TRC>500 μg/l), than did other fabrics. Fabric structure (for a particular material) significantly affects chemical off-gassing. Cotton typically used for polo shirt (knitted) off-gassed significantly (p<0.05) higher TRC for chemicals with molecular weight of ~100 (such as furfural) than did other cottons of woven style. The dyeing of fabric (white vs. black) had a limited effect on emission, while increasing contact time with ETS increased the intensity of chemical emissions. The mean TRC for cotton exposed for 12 min was nearly doubled than those exposed for 8min, but no difference existed for polyester.

Measurements of nitrous acid in commercial aircraft exhaust at the Alternative Aviation Fuel Experiment

The Alternative Aviation Fuel Experiment (AAFEX), conducted in January of 2009 in Palmdale, California, quantified aerosol and gaseous emissions from a DC-8 aircraft equipped with CFM56-2C1 engines using both traditional and synthetic fuels. This study examines the emissions of nitrous acid (HONO) and nitrogen oxides (NO(x) = NO + NO(2)) measured 145 m behind the grounded aircraft. The fuel-based emission index (EI) for HONO increases approximately 6-fold from idle to takeoff conditions but plateaus between 65 and 100% of maximum rated engine thrust, while the EI for NO(x) increases continuously. At high engine power, NO(x) EI is greater when combusting traditional (JP-8) rather than Fischer-Tropsch fuels, while HONO exhibits the opposite trend. Additionally, hydrogen peroxide (H(2)O(2)) was identified in exhaust plumes emitted only during engine idle. Chemical reactions responsible for emissions and comparison to previous measurement studies are discussed.

Thirdhand tobacco smoke: emerging evidence and arguments for a multidisciplinary research agenda

BACKGROUND

There is broad consensus regarding the health impact of tobacco use and secondhand smoke exposure, yet considerable ambiguity exists about the nature and consequences of thirdhand smoke (THS).

OBJECTIVES

We introduce definitions of THS and THS exposure and review recent findings about constituents, indoor sorption-desorption dynamics, and transformations of THS; distribution and persistence of THS in residential settings; implications for pathways of exposure; potential clinical significance and health effects; and behavioral and policy issues that affect and are affected by THS.

DISCUSSION

Physical and chemical transformations of tobacco smoke pollutants take place over time scales ranging from seconds to months and include the creation of secondary pollutants that in some cases are more toxic (e.g., tobacco-specific nitrosamines). THS persists in real-world residential settings in the air, dust, and surfaces and is associated with elevated levels of nicotine on hands and cotinine in urine of nonsmokers residing in homes previously occupied by smokers. Much still needs to be learned about the chemistry, exposure, toxicology, health risks, and policy implications of THS.

CONCLUSION

The existing evidence on THS provides strong support for pursuing a programmatic research agenda to close gaps in our current understanding of the chemistry, exposure, toxicology, and health effects of THS, as well as its behavioral, economic, and sociocultural considerations and consequences. Such a research agenda is necessary to illuminate the role of THS in existing and future tobacco control efforts to decrease smoking initiation and smoking levels, to increase cessation attempts and sustained cessation, and to reduce the cumulative effects of tobacco use on morbidity and mortality.

Effects of cigarette smoke residues from textiles on fibroblasts, neurocytes and zebrafish embryos and nicotine permeation through human skin

Toxic substances from cigarette smoke can attach to carpets, curtains, clothes or other surfaces and thus may pose risks to affected persons. The phenomenon itself and the potential hazards are discussed controversially, but scientific data are rare. The objective of this study was to examine the potential of textile-bound nicotine for permeation through human skin and to assess the effects of cigarette smoke extracts from clothes on fibroblasts, neurocytes and zebrafish embryos. Tritiated nicotine from contaminated cotton textiles penetrated through adult human full-thickness skin as well as through a 3D in vitro skin model in diffusion chambers. We also observed a significant concentration-dependent cytotoxicity of textile smoke extracts on fibroblast viability and structure as well as on neurocytes. Early larval tests with zebrafish embryos were used as a valid assay for testing acute vertebrate toxicity. Zebrafish development was delayed and most of the embryos died when exposed to smoke extracts from textiles. Our data show that textiles contaminated with cigarette smoke represent a potential source of nicotine uptake and can provoke adverse health effects.

Providing coaching and cotinine results to preteens to reduce their secondhand smoke exposure: a randomized trial

BACKGROUND

Secondhand smoke exposure (SHSe) poses health risks to children living with smokers. Most interventions to protect children from SHSe have coached adult smokers. This trial determined whether coaching and cotinine feedback provided to preteens can reduce their SHSe.

METHODS

Two hundred one predominantly low-income families with a resident smoker and a child aged 8 to 13 years who was exposed to two or more cigarettes per day or had a urine cotinine concentration ≥ 2.0 ng/mL were randomized to control or SHSe reduction coaching groups. During eight in-home sessions over 5 months, coaches presented to the child graphic charts of cotinine assay results as performance feedback and provided differential praise and incentives for cotinine reductions. Generalized estimating equations were used to determine the differential change in SHSe over time by group.

RESULTS

For the baseline to posttest period, the coaching group had a greater decrease in both urine cotinine concentration (P = .039) and reported child SHSe in the number of cigarettes exposed per day (child report, P = .003; parent report, P = .078). For posttest to month 12 follow-up, no group or group by time differences were obtained, and both groups returned toward baseline.

CONCLUSIONS

Coaching preteens can reduce their SHSe, although reductions may not be sustained without ongoing counseling, feedback, and incentives. Unlike interventions that coach adults to reduce child SHSe, programs that increase child avoidance of SHSe have the potential to reduce SHSe in all settings in which the child is exposed, without requiring a change in adult smoking behavior.

The ratio of a urinary tobacco-specific lung carcinogen metabolite to cotinine is significantly higher in passive than in active smokers

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol plus its glucuronides (total NNAL), metabolites of the lung carcinogen NNK, and total cotinine, metabolites of nicotine, are biomarkers of active and passive cigarette smoking. We calculated the total NNAL:total cotinine (×10(3)) ratio in 408 passive (infants, children, and adults) and 1088 active smokers. The weighted averages were 0.73 (95% confidence interval 0.71, 0.76) for passive smokers and 0.07 (0.06, 0.08) for active smokers (p < 0.0001). These results demonstrate that cotinine measurements may underestimate exposure of passive smokers to the lung carcinogen NNK in second-hand cigarette smoke. The total NNAL:total cotinine (×10(3)) ratio may provide an improved biomarker for evaluating the health effects of passive smoking.

Novel monitor paradigm for real-time exposure assessment

A wearable monitor that can reliably, accurately, and continuously measure personal exposure levels of various toxicants would not only accelerate the current environmental and occupational health and safety studies, but also enable new studies that are not possible with the current monitoring technology. Developing such a monitor has been a difficult challenge, and requires innovative sensing science and creative engineering. We have developed, built, and tested a wearable monitor for real-time detection of toxic hydrocarbons and acids in the environment. The monitor is low-cost, accurate, and user friendly. In addition, it can communicate wirelessly with a cell phone in which the monitoring results can be processed, displayed, stored, and transmitted to a designated computer. We have validated the functions and performance of the monitor, and carried out field tests with workers involving waste management, fire overhaul, and floor-cleaning activities, as well as with first- and second-hand smokers. The averaged exposure levels are in agreement with those determined by the standard NIOSH methods. The monitor provides accurate and real-time exposure assessment for the workers involving different activities. The real-time and continuous monitoring capability makes it possible to correlate the exposure levels with different activities and changes in the microenvironments. The monitor provides unprecedented real-time information that will help advance occupational safety and environmental health studies. It may also be used to better protect workers from occupational overexposure to toxic molecules.

Thirdhand smoke: a new dimension to the effects of cigarette smoke on the developing lung

The underlying mechanisms and effector molecules involved in mediating in utero smoke exposure-induced effects on the developing lung are only beginning to be understood. However, the effects of a newly discovered category of smoke, i.e., thirdhand smoke (THS), on the developing lung are completely unknown. We hypothesized that, in addition to nicotine, other components of THS would also affect lung development adversely. Fetal rat lung explants were exposed to nicotine, 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal (NNA), or 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), the two main tobacco-specific N-nitrosamine constituents of THS, for 24 h. We then determined key markers for alveolar paracrine signaling [epithelial differentiation markers surfactant phospholipid and protein synthesis; mesenchymal differentiation markers peroxisome proliferator-activated receptor γ (PPAR-γ), fibronectin and calponin], the BCL-2-to-Bax ratio (BCL-2/Bax), a marker of apoptosis and the involvement of nicotinic acetylcholine receptors (nAChR)-α3 and -α7 in mediating NNA's and NNK's effects on the developing lung. Similar to the effects of nicotine, exposure of the developing lung to either NNK or NNA resulted in disrupted homeostatic signaling, indicated by the downregulation of PPAR-γ, upregulation of fibronectin and calponin protein levels, decreased BCL-2/Bax, and the accompanying compensatory stimulation of surfactant phospholipid and protein synthesis. Furthermore, nAChR-α3 and -α7 had differential complex roles in mediating these effects. NNK and NNA exposure resulted in breakdown of alveolar epithelial-mesenchymal cross-talk, reflecting lipofibroblast-to-myofibroblast transdifferentiation, suggesting THS constituents as possible novel contributors to in utero smoke exposure-induced pulmonary damage. These data are particularly relevant for designing specific therapeutic strategies, and for formulating public health policies to minimize THS exposure.

Chemistry in indoor environments: 20 years of research

In the two decades since the first issue of Indoor Air, there have been over 250 peer-reviewed publications addressing chemical reactions among indoor pollutants. The present review has assembled and categorized these publications. It begins with a brief account of the state of our knowledge in 1991 regarding 'indoor chemistry', much of which came from corrosion and art conservation studies. It then outlines what we have learned in the period between 1991 and 2010 in the context of the major reference categories: gas-phase chemistry, surface chemistry, health effects and reviews/workshops. The indoor reactions that have received the greatest attention are those involving ozone-with terpenoids in the gas-phase as well as with the surfaces of common materials, furnishings, and the occupants themselves. It has become clear that surface reactions often have a larger impact on indoor settings than do gas-phase processes. This review concludes with a subjective list of major research needs going forward, including more information on the decomposition of common indoor pollutants, better understanding of how sorbed water influences surface reactions, and further identification of short-lived products of indoor chemistry. Arguably, the greatest need is for increased knowledge regarding the impact that indoor chemistry has on the health and comfort of building occupants.

PRACTICAL IMPLICATIONS

Indoor chemistry changes the type and concentration of chemicals present in indoor environments. In the past, products of indoor chemistry were often overlooked, reflecting a focus on stable, relatively non-polar organic compounds coupled with the use of sampling and analytical methods that were unable to 'see' many of the products of such chemistry. Today, researchers who study indoor environments are more aware of the potential for chemistry to occur. Awareness is valuable, because it leads to the use of sampling methods and analytical tools that can detect changes in indoor environments resulting from chemical processes. This, in turn, leads to a more complete understanding of occupants' chemical exposures, potential links between these exposures and adverse health effects and, finally, steps that might be taken to mitigate these adverse effects.

Metabolites of a tobacco-specific lung carcinogen in children exposed to secondhand or thirdhand tobacco smoke in their homes

BACKGROUND

People exposed to secondhand tobacco smoke (SHS) inhale the lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) which is metabolized to NNAL and its glucuroniders. These urinary metabolites, termed total NNAL, can be quantified. A related compound, iso-NNAL, has been proposed as a biomarker for exposure to smoke constituent residues on surfaces (thirdhand tobacco smoke). There is limited information in the literature on levels of total NNAL in children exposed to SHS.

METHODS

We recruited 79 parent--child dyads from homes where the enrolled parent was a cigarette smoker and visited their homes. Parents were asked questions, home ambient air quality was evaluated, and children provided urine samples. Urine was analyzed for total NNAL, total cotinine, total nicotine, and iso-NNAL.

RESULTS

Ninety percent of the children had detectable total NNAL in urine; total nicotine and total cotinine were also detected in most samples. There were significant positive relationships between biomarker levels and exposure of children in the home. Levels were highest in homes with no smoking restrictions. African American children had significantly higher levels than other children. iso-NNAL was not detected in any urine sample.

CONCLUSIONS

There was nearly universal exposure of children to the lung carcinogen NNK, due mainly to exposure to SHS from adult smokers in their homes.

IMPACT

Homes with adult smokers should adopt restrictions to protect their children from exposure to a potent lung carcinogen.

Determination of the nicotine metabolites cotinine and trans-3'-hydroxycotinine in biologic fluids of smokers and non-smokers using liquid chromatography-tandem mass spectrometry: biomarkers for tobacco smoke exposure and for phenotyping cytochrome P450 2A6 activity

The nicotine metabolite cotinine is widely used to assess the extent of tobacco use in smokers, and secondhand smoke exposure in non-smokers. The ratio of another nicotine metabolite, trans-3'-hydroxycotinine, to cotinine in biofluids is highly correlated with the rate of nicotine metabolism, which is catalyzed mainly by cytochrome P450 2A6 (CYP2A6). Consequently, this nicotine metabolite ratio is being used to phenotype individuals for CYP2A6 activity and to individualize pharmacotherapies for tobacco addiction. In this paper we describe a highly sensitive liquid chromatography-tandem mass spectrometry method for determination of the nicotine metabolites cotinine and trans-3'-hydroxycotinine in human plasma, urine, and saliva. Lower limits of quantitation range from 0.02 to 0.1ng/mL. The extraction procedure is straightforward and suitable for large-scale studies. The method has been applied to several thousand biofluid samples for pharmacogenetic studies and for studies of exposure to low levels of secondhand smoke. Concentrations of both metabolites in urine of non-smokers with different levels of secondhand smoke exposure are presented.