Measuring environmental tobacco smoke exposure in infants and young children through urine cotinine and memory-based parental reports: empirical findings and discussion

OBJECTIVE: This study examined the reliability and potential biases of two urine collection methods from which cotinine measures were obtained and the validity of memory-based parental reports of their children's exposure to environmental tobacco smoke (ETS). DESIGN: Structured interviews were conducted with mothers of infants and young children to obtain memory-based estimates of recent ETS exposure. Urine samples were collected through standard and cotton roll collection methods for cotinine analysis. SETTING: All interviews took place at an off-campus research facility. Urine samples were collected at the study office or the subjects' homes. PARTICIPANTS: Mothers were recruited from San Diego county sites of the Women, Infants, and Children (WIC) Supplemental Food and Nutrition Program. Sample 1 (infants) consisted of eight boys and eight girls aged 1-44 months (mean = 12.6 months). Sample 2 (children) included 10 boys and 10 girls aged 3-8 years (mean = 61.2 months). MAIN OUTCOME MEASURES: Urine cotinine and memory-based parent reports of ETS exposure from structured interviews. RESULTS: There was overall high reliability for urine cotinine measures and no effect of collection method on urine cotinine levels. Memory-based reports obtained from smoking mothers showed moderately strong and consistent linear relationships with urine cotinine measures of their infants and children (r = 0.50 to r = 0.63), but not for reports obtained from non-smoking mothers. CONCLUSIONS: Memory-based parental reports of short-term ETS exposure can play an important role in quantifying ETS exposure in infants and children.     

Secondhand smoke exposure in Mexican discotheques.

This study describes the impact of exposure to secondhand smoke for subjects who spend time in a discotheque, by comparing within-subject baseline and postexposure urinary cotinine levels. A total of 100 nonsmoking volunteers from a central region of Mexico provided a urine sample before entering a discotheque and another sample an average of 6 hr after the end of exposure. Concentrations of cotinine and its metabolite, trans-3'-hydroxycotinine, were measured in the urine by liquid chromatography-mass spectrometry. In females the average preexposure level of urinary cotinine was 2.2 ng/ml, and the average postexposure level was significantly higher, at 15.7 ng/ml. In males the average preexposure level of cotinine was 3.7 ng/ml, compared with 49.1 ng/ml in the postexposure assessment. The highest postexposure values were found in men younger than 22 years old with a value of 469.5 ng/ml. Exposure to secondhand smoke is a serious health risk. Our findings are important given that many of our subjects were exposed to substantial amounts of secondhand smoke in discotheques, as evidenced by the high urinary cotinine and 3'-hydroxycotinine concentrations. These findings support the need to prohibit smoking in discotheques to protect nonsmokers' health.     

Behavioral counseling for reducing children's ETS exposure: implementation in community clinics.

The present randomized controlled trial tested the effectiveness of a behavioral counseling program for reducing children's exposure to environmental tobacco smoke (ETS). Counseling was delivered by clinic staff as part of well-child health care services in a community clinic setting. A total of 150 mothers with children aged 4 years or younger were recruited. Parent-reported and children's urinary cotinine measures of ETS exposure were obtained at baseline, 3 months, 6 months (post-test), and 12 months (follow-up). Saliva samples were obtained from mothers who reported quitting smoking, for objective verification by thiocyanate analysis. After baseline, mothers were randomly assigned to a measures-only control condition or an intervention consisting of seven behavioral counseling sessions over 6 months. Counseling included behavioral contracting, self-monitoring, problem solving, and positive reinforcement. Results indicated acceptable test-retest reliability and validity of measures. Parent-reported measures indicated that, in both groups, children's exposure to their mothers' tobacco smoke in the home and to all tobacco smoke declined steeply from baseline to 6 months post-test, and remained essentially level during follow-up. Mothers' smoking rates followed the same pattern. Children's urinary cotinine concentrations did not show significant change over time in either group. Findings on the fidelity of treatment implementation suggest that the structure and funding of the community clinic health care system and associated staff turnover and training issues resulted in participants receiving a less efficacious intervention than in our past efficacy trials. Implications for future effectiveness trials are discussed.     

Exposure of hospitality workers to environmental tobacco smoke

OBJECTIVE: To determine quantitatively the extent of exposure of hospitality workers to environmental tobacco smoke (ETS) exposure during the course of a work shift, and to relate these results to the customer smoking policy of the workplace. SUBJECTS: Three categories of non-smoking workers were recruited: (1) staff from hospitality premises (bars and restaurants) that permitted smoking by customers; (2) staff from smokefree hospitality premises; and (3) government employees in smokefree workplaces. All participants met with a member of the study team before they began work, and again at the end of their shift or work day. At each meeting, participants answered questions from a standardised questionnaire and supplied a saliva sample. MAIN OUTCOME MEASURES: Saliva samples were analysed for cotinine. The difference between the first and second saliva sample cotinine concentrations indicated the degree of exposure to ETS over the course of the work shift. RESULTS: Hospitality workers in premises allowing smoking by customers had significantly greater increases in cotinine than workers in smokefree premises. Workers in hospitality premises with no restrictions on customer smoking were more highly exposed to ETS than workers in premises permitting smoking only in designated areas. CONCLUSIONS: Overall, there was a clear association between within-shift cotinine concentration change and smoking policy. Workers in premises permitting customer smoking reported a higher prevalence of respiratory and irritation symptoms than workers in smokefree workplaces. Concentrations of salivary cotinine found in exposed workers in this study have been associated with substantial involuntary risks for cancer and heart disease.     

Levels and sources of personal inhalation exposure to volatile organic compounds

Personal exposures to VOCs of 12 urban dwellers were measured directly via personal monitoring and indirectly via static monitoring combined with personal activity diaries. Over 5-10 days, day-to-day variations in personal exposures of individuals were substantial, with statistically significant (p<0.05) deviation from the normal distribution observed for daily exposures to one or more VOCs for several subjects. Daytime concentrations generally exceeded night time, with day:night mean concentration ratios for each sampling day >1 for most VOCs, with the maximum (3.85) occurring for 1,3-butadiene. Exposure in the home contributed 50-80% of overall individual exposure to 1,3-butadiene and benzene. For most VOCs, while absolute values of direct and indirect exposure estimates were significantly different (p<0.05), linear regression of direct and indirect exposure estimates revealed statistically significant correlation (p<0.01), confirming previous observations that indirect monitoring can provide satisfactory estimates of personal inhalation exposure to VOCs. ETS, the use of vehicles, and heating (but not cooking) all made appreciable contributions to personal exposure to all target VOCs.     

The dog as a passive smoker: effects of exposure to environmental cigarette smoke on domestic dogs.

Of the few studies available regarding the effects of smoking on animals, most of them involve animals actively smoking through the use of a mask or tracheostomy. The present study investigated the effects of passive smoke exposure on domestic dogs. The sample comprised 30 Yorkshire terriers (18 males) ranging in age from 27 to 106 months (M = 38.6+/-15.8) and weighing 1.9-4.0 kg (M = 3.04+/-0.48). Half of the dogs came from homes where residents smoked at least 20 cigarettes/day for a minimum of 24 months, and the other half were from homes without smokers. All animals were subjected to bronchoalveolar lavage to determine cell populations and the presence of anthracosis in macrophage cytoplasm; in addition, a carinal biopsy was obtained. To characterize environmental cigarette smoke exposure, urinary cotinine was determined by an immunochromatographic assay. Cotinine was not detected in the urine of dogs not exposed to cigarette smoke, whereas exposed dogs tested positive. In dogs exposed to cigarette smoke, macrophage and lymphocyte populations were significantly increased (p<.05) and anthracosis was present in the cytoplasm of macrophages. The measurement of urinary cotinine by an immunochromatographic assay is an effective method that can be used to confirm environmental tobacco exposure. Cytological analysis of bronchoalveolar lavage fluid demonstrated airway alterations triggered by passive exposure to tobacco smoke in domestic animals.     

Occult maternal exposure to environmental tobacco smoke exposure

Background

Environmental tobacco smoke (ETS) is a recognised air pollutant. Its harmful effects have been found to be implicated in health disorders, including unfavourable pregnancy outcomes. The discrepancy between self‐reported emvironmental tobacco smoke exposure and cotinine levels in pregnant non‐smokers in France was examined.

Method

Plasma cotinine was determined by a CPG‐SM method on women who had answered a self‐questionnaire describing their habits and environment during pregnancy.

Results

Of 698 pregnant women reported as non‐smokers, 305 (43.7%) claimed not to be exposed to ETS, yet 196 of these (64.3%) had plasma cotinine levels above the limit of detection.

Conclusion

Self‐reported data on ETS exposure in pregnant women therefore underestimate actual exposure. However, cotinine assay cab rectify this misclassification. An accurate identification of this risk factore will help to change attitudes towards ETS and avert its adverse effects on mother and fetus.Although environmental tobacco smoke (ETS) has not yet been monitored in France, it is probably, as in the United States National Health and Nutrition Examination Survey (1999–2002), a major source of indoor air pollution. Low levels of ETS exposure can result in unfavourable pregnancy outcomes,^1,2 and many pregnant women still believe that not smoking is sufficient to protect their fetus from ETS. Moreover, far less attention has been paid to perinatal ETS exposure. A better appraisal of these non‐maternal sources and measurement of corresponding prenatal exposure will provide a useful basis for further work and discussion on its effects.     

Japanese spousal smoking study revisited: how a tobacco industry funded paper reached erroneous conclusions

Objectives: To provide a participant''s account of the development of a paper commissioned by the tobacco industry examining the reliability of self reported smoking status; to redress the distorted report of this Japanese spousal smoking study which evaluated the reliability and validity of self reported smoking status, and estimated confounding by diet and lifestyle factors. Design: Repeated interviews on smoking status and its verification by environmental and biological markers for environmental tobacco smoke (ETS) exposure. Setting: Urban wives in Osaka City and Sizuoka City, Japan Participants: Semi-random sampling of 200 wives in each city. From the Osaka subjects, 100 non-smoking wives were selected for the validity study. Main outcome measures: Kappa coefficient for reliability of self reported smoking status. Correlation coefficients between environmental nicotine concentration, cotinine in saliva and urine, and self reported smoking status. Results: The κ coefficient for the repeated interview was high suggesting sufficient reliability of the response. The proportion of self reported current smokers misclassified as non-smokers was equivalent to the misclassified self reported non-smokers. Ambient concentration of nicotine and personal exposure to nicotine correlated with each other and also with salivary cotinine and self reported ETS exposure but not with urinary cotinine/creatinine ratio (CCR). There was no major difference in diet and lifestyle related to husband''s smoking status. Conclusion: Self reported smoking status by Japanese wives shows high reliability. It also shows high validity when verified by both nicotine exposure and salivary cotinine, but not by CCR. A previous report questioning the credibility of self reported smoking status, based on questionable CCR, could thus be of dubious validity. In addition, possible dietary and lifestyle confounding factors associated with smoking husbands were not demonstrable, a finding not reported previously. Using all the data from this project changes the conclusion of the previous published report. In addition to the distortion of scientific findings by a tobacco industry affiliated researcher, anti-smoking campaigners made attempts to intimidate and suppress scientific activities. These distortions of science should be counteracted.     

Characterizing and biological monitoring of polycyclic aromatic hydrocarbons in exposures to diesel exhaust

Polycyclic aromatic hydrocarbons (PAHs) are one of the most important and carcinogenic components in diesel exhaust (DE). Therefore, ambient PAHs concentrations were measured and characterized for work areas in a locomotive engine inspection plant. Pre- and post-shift urine samples and concurrent air samples were collected on 17 workers to measure the concentration of urinary 1-hydroxypyrene (1-OHP), a metabolite of pyrene. Increased urinary 1-OHP concentrations were observed over at least three consecutive sampling days. The biological kinetics of pyrene metabolism was studied with a one-compartment pharmokinetic model. The conversion rate and elimination rate of 1-OHP were estimated using nonlinear mixed-effects model, and validated with multiple nonlinear regression models by assessing the pattern of elimination rates of each worker separately. Urinary 1-OHP was confirmed to be a sensitive marker of PAHs exposure with mean half-life of 29 h in this population of Chinese workers. The study results would be beneficial to future occupational and environmental studies of PAH exposure.     

Households contaminated by environmental tobacco smoke: sources of infant exposures

Objectives: To examine (1) whether dust and surfaces in households of smokers are contaminated with environmental tobacco smoke (ETS); (2) whether smoking parents can protect their infants by smoking outside and away from the infant; and (3) whether contaminated dust, surfaces, and air contribute to ETS exposure in infants.

Design: Quasi-experiment comparing three types of households with infants: (1) non-smokers who believe they have protected their children from ETS; (2) smokers who believe they have protected their children from ETS; (3) smokers who expose their children to ETS.

Setting: Homes of smokers and non-smokers.

Participants: Smoking and non-smoking mothers and their infants 1 year.

Main outcome measures: ETS contamination as measured by nicotine in household dust, indoor air, and household surfaces. ETS exposure as measured by cotinine levels in infant urine.

Results: ETS contamination and ETS exposure were 5–7 times higher in households of smokers trying to protect their infants by smoking outdoors than in households of non-smokers. ETS contamination and exposure were 3–8 times higher in households of smokers who exposed their infants to ETS by smoking indoors than in households of smokers trying to protect their children by smoking outdoors.

Conclusions: Dust and surfaces in homes of smokers are contaminated with ETS. Infants of smokers are at risk of ETS exposure in their homes through dust, surfaces, and air. Smoking outside the home and away from the infant reduces but does not completely protect a smoker's home from ETS contamination and a smoker's infant from ETS exposure.

     

Comparability and repeatability of methods for estimating the dietary intake of the heterocyclic amine contaminant 2-amino-1-methyl-6-phenylimidazo[4,5b]pyridine (PhIP)

Inconsistent risk estimates for dietary heterocyclic amine (HCA) exposure and cancers may be due to differences in exposure assessment methods and the associated measurement error. We evaluated repeatability and comparability of intake estimates of the HCA 2-amino-1-methyl-6-phenylimidazo[4,5b]pyridine (PhIP) among two food frequency questionnaire (FFQ) collections, three diary collections, and three measurements of urinary PhIP and its metabolites in 36 non-smokers in Baltimore, Maryland, during 2004-2005. Collections spanned ～9 months. Method repeatability was characterised with intraclass correlation coefficients (ICCs). Comparability among methods was assessed with Spearman correlation coefficients. Within-subject variability in PhIP intake was comparably high across all methods (ICCs of 0.20, 0.30, and 0.15 for FFQ, diary, and creatinine-adjusted urinary PhIP, respectively). Mean diary-based PhIP intake and mean urinary PhIP concentration were strongly correlated when restricting the analysis to participants with at least one non-zero diary-based estimate of PhIP intake (n?=?15, r?=?0.75, p?=?0.001), but not in the full study population (n?=?36, r?=?0.18, p?=?0.28). Mean PhIP intake from the FFQ was not associated with that either based on the diary or urinary PhIP separately, but was modestly correlated with a metric that combined the diary- and biomarker-based approaches (r?=?0.30, p?=?0.08). The high within-subject variability will result in significantly attenuated associations if a single measure is used to estimate exposure within an epidemiologic study. Improved HCA assessment tools, such as a combination of methods or validated biomarkers that capture long term exposure, are needed.     

Assessment of dietary exposure to ochratoxin A in the UK using a duplicate diet approach and analysis of urine and plasma samples

The approach to assess exposure to ochratoxin A from the diet by the analysis of human plasma and urine samples has been developed. Composite duplicate diet samples from 50 individuals and corresponding plasma and urine samples were obtained over 30 days. Samples were analysed using sensitive methods capable of measuring ochratoxin A at 0.001ng g -1 in food, 0.1ng ml -1 in plasma and 0.01ng ml -1 in urine. Analysis of the foods indicated ochratoxin A levels contributing to an average intake in the range 0.26-3.54ng kg -1 bw day -1 over the 30 days. Ochratoxin A was found in all plasma samples and in 46 urine samples. The correlation between the plasma ochratoxin A levels and ochratoxin A consumption was not significant (95% confidence limit). However, a significant correlation was found between ochratoxin A consumption and the urine ochratoxin A concentration expressed as the total amount excreted. This new work offers the possibility of using ochratoxin A in urine as a simple and reliable biomarker to estimate exposure to this mycotoxin.     

Urine cotinine as an index of smoking status in smokers during 96-hr abstinence: comparison between gas chromatography/mass spectrometry and immunoassay test strips.

Biomarkers such as carbon monoxide (CO) and cotinine (a nicotine metabolite) are used in tobacco cessation studies to assess smoking status. CO is easy to assess, is inexpensive, and provides immediate results. However, the short half-life of CO may limit its ability to identify smokers who have abstained for several hours. Quantitative methods (e.g., gas chromatography/mass spectrometry, or GC/MS) for measuring urine cotinine, which has a longer half-life, are valid and reliable, though costly and time consuming. Recently developed semiquantitative urine cotinine measurement techniques (i.e., urine immunoassay test strips, or ITS) address these disadvantages, though the value of ITS as a means of identifying abstaining smokers has not been evaluated. The present study examined ITS as a measure of smoking status in temporarily abstaining smokers. A total of 236 breath and urine samples were collected from smokers who participated in two separate studies involving three independent, 96-hr (i.e., Monday-Friday), Latin-square-ordered, abstinence or smoking conditions; a minimum 72-hr washout separated each condition. Each urine sample was analyzed with GC/MS and ITS. Under these study conditions, CO demonstrated moderate sensitivity (83.1%) and strong specificity (100%), whereas ITS assessment showed strong sensitivity (98.5%) and weak specificity (58.5%). In this study of short-term abstinence, ITS classified as nonabstinent nearly half of the samples collected from abstaining smokers. However, it classified nearly all nonabstinent smokers as currently smoking. Validation of ITS using GC/MS results from smokers undergoing more than 96 hr of abstinence may be valuable.     

Enzymeimmunoassay of oestradiol,testosterone and progesterone in urine samples from female mice before and after insemination

ELISA measurements of 17beta-oestradiol, testosterone and progesterone were determined for urine samples collected non-invasively from female mice. Initial samples were collected during 5 successive days while mature female mice were isolated and cyclic. Subsequently, female mice were inseminated and additional urine samples were collected during days 2-6 after observation of copulatory plugs. Measurements of oestradiol and testosterone showed variance over days within individuals and did not significantly differ in measurements taken before or after insemination. Progesterone concentrations were significantly higher after insemination compared with before mating. In a second sample of inseminated females, urinary progesterone was measured during days 2-18 of pregnancy. Most females showed high urinary progesterone up to day 10 of pregnancy and lower concentrations during the remainder of gestation. These results indicate that urinary progesterone reflects established systemic increases of this hormone during pregnancy.     

Perchlorate exposure and dose estimates in infants

Perchlorate is a naturally occurring inorganic anion used as a component of solid rocket fuel, explosives, and pyrotechnics. Sufficiently high perchlorate intakes can modify thyroid function by competitively inhibiting iodide uptake in adults; however, little is known about perchlorate exposure and health effects in infants. Food intake models predict that infants have higher perchlorate exposure doses than adults. For this reason, we measured perchlorate and related anions (nitrate, thiocyanate, and iodide) in 206 urine samples from 92 infants ages 1-377 days and calculated perchlorate intake dose for this sample of infants. The median estimated exposure dose for this sample of infants was 0.160 μg/kg/day. Of the 205 individual dose estimates, 9% exceeded the reference dose of 0.7 μg/kg/day; 6% of infants providing multiple samples had multiple perchlorate dose estimates above the reference dose. Estimated exposure dose differed by feeding method: breast-fed infants had a higher perchlorate exposure dose (geometric mean 0.220 μg/kg/day) than infants consuming cow milk-based formula (geometric mean 0.103 μg/kg/day, p < 0.0001) or soy-based formula (geometric mean 0.027 μg/kg/day, p < 0.0001), consistent with dose estimates based on dietary intake data. The ability of perchlorate to block adequate iodide uptake by the thyroid may have been reduced by the iodine-sufficient status of the infants studied (median urinary iodide 125 μg/L). Further research is needed to see whether these perchlorate intake doses lead to any health effects.     

吸烟者转抽加热卷烟的抽吸行为和烟碱暴露

为研究吸烟者转抽加热卷烟后抽吸行为和烟碱暴露水平的变化,招募50名抽吸卷烟的志愿者,分为两组,分别转抽加热卷烟IQOS和国内加热卷烟M。转抽前后通过问卷调查获得志愿者的基线资料,使用CReSS吸烟行为记录仪测试吸烟行为参数,采用HPLC-MS/MS测定志愿者基线和转抽后尿样中的烟碱暴露生物标志物。结果表明:①志愿者转抽加热卷烟后抽吸行为基本保持不变,抽吸容量和抽吸时间均未发生显著性改变,但抽吸间隔明显缩短,两组志愿者抽吸卷烟时抽吸间隔分别为（14.3±8.0）s和（15.3±9.0）s,转抽加热卷烟后抽吸间隔分别为（9.8±8.3）s和（9.7±5.4）s。②转抽后志愿者尿液中烟碱总代谢物和可替宁等烟碱暴露生物标志物的浓度水平也未发生显著性改变。③转抽IQOS后志愿者的抽吸行为与转抽M后的志愿者没有明显差异,两组志愿者尿液中烟碱总代谢物和可替宁的水平也近似。      

Evaluation of urinary methoxyphenols as biomarkers of woodsmoke exposure

Urinary methoxyphenols have been proposed as biomarkers for woodsmoke exposure, but the relationship between exposure and urinary methoxyphenol concentrations has not been characterized. We collected personal particulate matter2.5 and urine samples from 9 adults experimentally exposed to smoke from an open wood fire to characterize this relationship. Personal exposures (PM2.5 mean 1500 microg/ m3) varied 3.5-fold. Twenty-two methoxyphenols, levoglucosan, and 17 polynuclear hydrocarbons were quantified by gas chromatography/mass spectrometry assays for personal filter samples and urine samples. Most methoxyphenols had measurable preexposure levels. Propylguaiacol, syringol, methylsyringol, ethylsyringol, and propylsyringol had peak urinary concentrations after the woodsmoke exposure. Eight subjects had peak urinary elimination of methoxyphenols within 6 h (t1/2 3-5 h), whereas one had delayed elimination. Several metrics for urinary excretion were evaluated. Analyte concentration was greatly affected by diuresis. Excretion rate and analyte concentrations normalized by creatinine gave a clearer signal and were equivalent in predictive ability. Twelve-hour average creatinine-normalized concentrations of each of the 5 methoxyphenols gave a Pearson correlation > or = 0.8 with their particle-phase concentration. The sum of urinary concentrations for the 5 methoxyphenols versus levoglucosan on personal filters gave a regression coefficient of 0.75. This sum versus PM2.5 gave a regression coefficient of 0.79. The intercept of this regression suggests that the threshold for detection of an acute exposure event would be approximately 760 microg/m3 particulate matter from woodsmoke. The signal-to-noise (12-h postexposure average/preexposure average) ranged from 1.1 to 8 for the 5 methoxyphenols. Analysis of multiple compounds provided assurance that elevations were not artifactual due to food or other products.     

Smokeless tobacco topography and toxin exposure.

This study examined the relationship between oral smokeless tobacco (ST) topographical measures and biomarkers of tobacco and carcinogen exposure. During 2 weeks of baseline ad libitum ST use, 54 male participants (mean age=32.1+/-7.5 years) were required to record the time each dip was placed in and removed from their mouths. Urine samples were collected twice during baseline and analyzed for nicotine, cotinine, and their glucuronides (total nicotine and total cotinine) and for metabolites of the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides (total NNAL). The results suggest that frequency and duration measures of ST use (p<.01 to p<.001), particularly total dip duration, are significantly correlated with total cotinine, total nicotine, and total NNAL. These results suggest that how long a ST user has tobacco in his mouth is most predictive of tobacco toxin exposure.     

Salivary cotinine concentration versus self-reported cigarette smoking: Three patterns of inconsistency in adolescence.

The present study examined the extent and sources of discrepancies between self-reported cigarette smoking and salivary cotinine concentration among adolescents. The data are from household interviews with a cohort of 1,024 adolescents from an urban school system. Histories of tobacco use in the last 7 days and saliva samples were obtained. Logistic regressions identified correlates of three inconsistent patterns: (a) Pattern 1-self-reported nonsmoking among adolescents with cotinine concentration above the 11.4 ng/mg cutpoint (n = 176), (b) Pattern 2-low cotinine concentration (below cutpoint) among adolescents reporting having smoked within the last 3 days (n = 155), and (c) Pattern 3-high cotinine concentration (above cutpoint) among adolescents reporting not having smoked within the last 3 days (n = 869). Rates of inconsistency were high among smokers defined by cotinine levels or self-reports (Pattern 1 = 49.1%; Pattern 2 = 42.0%). Controlling for other covariates, we found that reports of nonsmoking among those with high cotinine (Pattern 1) were associated with younger age, having few friends smoking, little recent exposure to smokers, and being interviewed by the same interviewer as the parent and on the same day. Low cotinine concentration among self-reported smokers (Pattern 2) was negatively associated with older age, being African American, number of cigarettes smoked, depth of inhalation, and exposure to passive smoke but positively associated with less recent smoking and depressive symptoms. High cotinine concentrations among self-reported nonsmokers was positively associated with exposure to passive smoke (Pattern 3). The data are consonant with laboratory findings regarding ethnic differences in nicotine metabolism rate. The inverse relationship of cotinine concentration with depressive symptoms has not previously been reported. Depressed adolescent smokers may take in smaller doses of nicotine than nondepressed smokers; alternatively, depressed adolescents may metabolize nicotine more rapidly.     

Annual variation of dietary deoxynivalenol exposure during years of different Fusarium prevalence: a pilot biomonitoring study

Dietary exposure to deoxynivalenol (DON) has been reported previously in the UK, but levels were low and most individuals are well protected by the maximum permitted levels in food set by the European Commission. However, no information is available on annual fluctuation in dietary DON exposure. We hypothesised that dietary DON exposure may vary when individuals consume cereals derived from harvests with low (2011) and high (2012) Fusarium prevalence. In this pilot study, spot urine samples were collected in years 1 and 2 from 15 volunteers following their habitual diet. Urinary DON was analysed by LC-MS/MS to estimate 24-h DON excretion and daily dietary DON intake. DON was detectable in all urine samples with an average excretion of 10.08 ± 9.13 µg/24-h urine in year 1 which significantly (p = 0.005) increased to 24.84 ± 13.83 µg/24-h urine in year 2. This resulted from an estimated dietary intake of 195.94 ± 166.44 ng DON kg^–1 BW in year 1 and 518.64 ± 292.49 ng DON kg^–1 BW in year 2. Based on these estimates, the tolerable daily intake for DON was exceeded in 13% of occasions in year 2 and none in year 1. This pilot study is based on estimates of DON intake derived from urinary DON excretion. Results suggest that DON exposure varies annually and that current maximum levels might not sufficiently protect consumers during years of high Fusarium prevalence.