Renal excretion mechanisms are xenobiotic-specific; therefore, accurate exposure assessment requires an understanding of relationships of xenobiotic biomarker concentration and excretion rate to urine flow, specific gravity and creatinine concentration. Twenty-four-hour urine collection for xenobiotic exposure assessment is considered the "gold standard" procedure. Random spot-urine collection is convenient and minimizes subject compliance concerns but requires that normalization techniques be employed to account for diuresis and diurnal variation in xenobiotic biomarker excretion. This paper examines and makes recommendations concerning normalization techniques and conditions under which spot-urine results most accurately reflect 24-h urine results. Specific gravity, creatinine, and xenobiotic biomarkers were determined in smokers' spot and 24-h urines. Normalization techniques were applied, variance-component analyses were performed to estimate variability, spot urines were pooled mathematically to simulate 24-h urines and analyses of variance were performed to evaluate spot urines' ability to reflect 24-h urine concentrations. For each xenobiotic biomarker concentration, log-linear relationships were observed with urine flow, specific gravity, and creatinine. For most xenobiotic biomarker excretion rates, log-linear relationships were observed with urine flow; creatinine, however, was unaffected by urine flow. The conventional creatinine ratio-normalization technique demonstrated greater variability (within-day, between-day and between-subject) than other normalization techniques. Comparisons of simulated 24-h urines to spot urines suggest that spot-urine collection be performed only between 2 p.m. and 2 a.m. and that the modified specific-gravity-adjusted-creatinine ratio-normalization technique and the creatinine-regression normalization technique yield the best agreement between spot- and simulated 24-h urine results.

An SPE-LC-MS/MS method was developed, validated and applied to the determination of nicotine and five major metabolites in human urine: cotinine, trans-3'-hydroxycotinine, nicotine-N-glucuronide, cotinine-N-glucuronide and trans-3'-hydroxycotinine-O-glucuronide. A 500 microL urine sample was pH-adjusted with phosphate buffer (1.5 mL) containing nicotine-methyl-d3, cotinine-methyl-d3 and trans-3'-hydroxycotinine-methyl-d3 internal standards. For the unconjugated metabolites, an aliquot (800 microL) of the buffered solution was applied to a 30 mg Oasis HLB-SPE column, rinsed with 2% NH4OH/H2O (3.0 mL) and H2O (3.0 mL) and eluted with methanol (500 microL). The eluate was analyzed isocratically (100% methanol) by LC-MS/MS on a diol column (50 x 2.1 mm). For the total metabolites, a beta-glucuronidase/buffer preparation (100 microL) was added to the remaining buffered solution and incubated at 37 degrees C (20 h). An aliquot (800 microL) of the enzymatically treated buffered solution was extracted and analyzed in the same manner. The conjugated metabolites were determined indirectly by subtraction. The quantitation range of the method (ng/mL) was 14-10,320 for nicotine, 15-9800 for cotinine and 32-19,220 for trans-3'-hydroxycotinine. The validated method was used to observe diurnal variations from a smoker's spot urine samples, elimination half-lives from a smoker's 24 h urine samples and metabolite distribution profiles in the spot and 24 h urine samples.

This study tested the hypotheses that (1) increased platelet aggregation, as measured by 2,3-dinor-thromboxane B(2) (Tx-M) and 2,3-dinor-6-keto-prostaglandin F(1alpha) (PGI-M), and (2) increased oxidative stress, as measured by 8-Hydroxy-2'-deoxyguanosine (8-OHdG), would occur in ETS-exposed nonsmokers as compared with non-ETS-exposed nonsmokers. The concentrations of the stable urinary metabolites of thromboxane (Tx-M) and prostacyclin (PGI-M), cortisol and 8-OHdG were measured in a 24-h urine sample from 3 groups of subjects: 21 nonsmokers with minimal (15 min or less per day) ETS exposure (termed non-ETS-exposed), 22 nonsmokers with at least 5 h per day of ETS exposure (termed ETS-exposed), and 20 cigarette smokers who served as a positive control group. The self-reported levels of ETS exposure were verified by personal air monitors. As compared with either group of nonsmokers, cigarette smokers excreted significantly more urinary Tx-M. Non-ETS-exposed nonsmokers showed a statistically significantly higher level of urinary Tx-M over that seen in nonsmokers with considerably more ETS exposure. Urinary concentrations of PGI-M were marginally higher in the smokers and did not differ between the nonsmoker groups. Nonsmokers exposed to at least five h of ETS per day did not have significantly higher excretion of 8-OHdG than non-ETS-exposed nonsmokers. The results from this study suggest that platelet aggregation, as measured by the thromboxane metabolite Tx-M and prostacyclin metabolite PGI-M, is not associated with ETS exposure. Therefore, platelet aggregation is not a plausible or quantitatively consistent mechanism to explain the nonlinear dose-response hypothesis of cardiovascular disease and ETS exposure.

Because of a lack of representative data on smoking status misclassification among U.S. married females, a two-part study was conducted. Part I was conducted to obtain nationally representative estimates of the percentage of U.S. women who report themselves to be current, former, and never smokers, to determine the concordance of smoking habits among spouse pairs, and to establish field quotas and probability weightings for Part II. Part II was conducted to determine smoker misclassification rates using salivary cotinine as an indication of active smoking. Part I, conducted in January 25–29, 1992, utilized random-digit dialing telephone inter-viewing throughout the 48 contiguous United States. Part II, conducted from February 19, 1992 to March 7, 1992, was a mall-intercept study in nine geographically disperse U.S. cities and it involved interviewing and saliva collection. Among married U.S. women, 25% reported they were current smokers, 22% reported they were former smokers, and 53% reported they were never smokers. Using a cotinine concentration of either >35 ng/ml or >106 ng/ml to indicate regular smoking, 3.61% and 2.55% of regular smokers, respectively, reported themselves to be never smokers. The concordance ratio, an important parameter in correcting for non-differential misclassification bias, was found to be 5.52. In addition, an indication of substantial differential misclassification was found between exposed and unexposed populations. This type of misclassification bias has previously not been accounted for in the adjustment of epidemiology-based risk assessments of tobacco smoke exposure and lung cancer. Taken together, these data suggest that misclassification bias alone is likely to explain any lung cancer risk elevation observed in the U.S. epidemiology of environmental tobacco smoke exposure among non-smoking women.

The environmental tobacco smoke (ETS) yield of selected analytes was determined for the 50 top-selling U.S. cigarette brand styles (1991) and the University of Kentucky Research cigarette, K1R4F. ETS was generated by smokers in an environmental test chamber. Analytes determined included real-time measurements of nicotine, 3-ethenylpyridine, respirable suspended particles (RSP), carbon monoxide, and total hydrocarbons by flame ionization detector response (FID). Real-time RSP values were determined independently by a piezoelectric balance and real-time aerosol monitor (RAM). Additional analytes determined on a time-integrated basis included: nicotine, 3-ethenylpyridine, myosmine, RSP, ultraviolet particulate matter (VUPM), fluorescent particulate matter (FPM), solanesol, scopoletin, formaldehyde, acetaldehyde, acetone, catechol, ammonia, 34 volatile organic compounds (VOCs), and total VOCs (estimated by GC/mass spectrometric response). In general, lowering mainstream tar resulted in lower ETS emissions. The current study showed that ETS-RSP and nicotine were not predictive of each other. In fact, this ETS market brand style comparison showed a poor relationship between ETS nicotine and ETS-RSP. ETS analyte yields are summarized by mainstream tar categories, and overall sales-weighted average yields are calculated. Sales-weighted average ETS-RSP yields for full flavor (FF), full flavor low tar (FFLT), and ultra low tar (ULT) were 14.86, 12.30, and 10.51 mg/cig, respectively. The average RSP yield for all cigarettes evaluated was 13.67 mg/cig. These results, based on 65.3% of the U.S. cigarette market, should enable better estimations of the contribution of ETS to indoor air.

A monitoring system, calibration system and bar code-based, computer sample tracking system For measuring personal exposures to environmental tobacco smoke (ETS) are described. The monitoring system collects both vapor and particulate phase ETS analytes on a sorbent tube and filter, respectively, using a single sampling pump. Several battery pack configurations are described which enable continuous sampling times of 16, 28 and 48 h. Detailed methodologies are presented for determining nicotine, 5-ethenylpyridine and myosmine in the vapor phase and respirable suspended particles, solanesol, scopoletin, UVPM and FPM in the particulate phase. Experiments conducted in a controlled-environment test chamber show that all analytes increase linearly with the number of cigarettes smoked. In addition, 3-ethenylpyridine is shown to track closely the vapor phase of ETS (as measured by CO and FID) while nicotine poorly estimates the vapor phase. These data support previously published findings that 3-ethenylpyridine is superior to nicotine as an ETS vapor phase marker.

One hundred-four self-reported nonsmoking married women participated in a home and workplace personal environmental tobacco smoke (ETS) exposure study for 33 volatile organic compounds (VOCs), total volatile organic compounds (TVOCs), respirable suspended particulate matter (RSP), and ETS-RSP. The women were selected and classified according to socioeconomic categories based on age (25–39 y and 40+ y), total annual household income (<$40K and >$40K), and reported ETS exposure status at home and at work (SH = smoking home, NSH = nonsmoking home, SW = smoking work, and NSW = nonsmoking work). Saliva samples were collected at the start and at the end of the study for cotinine determinations. Five participants (4.8% of the total), married to smokers and working in smoking workplaces, were excluded because they had average salivary cotinine concentrations greater than 10 ng/mL indicating that they were likely smokers. The background correction factor for cotinine (SH/NSH) or Z, indicated that total exposure was 4.8 times greater for those living with a smoker versus those not living with a smoker. Apportionment of TVOCs indicated that 3.4% of the TVOCs in the smoking homes and 0.8% of the TVOCs in the smoking workplaces were attributable to ETS. Apportionment of benzene and styrene indicated that 11.4% and 13.4%, respectively, were attributable to ETS in smoking homes; 11.5% and 6.2%, respectively, were attributable to ETS in smoking workplaces. RSP apportionment based on solanesol particulate matter (Sol-PM) indicated that 28.7% of the RSP in smoking homes and 22.7% of the RSP in smoking workplaces were attributable to ETS. RSP apportionment based on scopoletin particulate matter (Sco-PM) indicated that 12.9% of the RSP in smoking homes and 9.6% of the RSP in smoking workplaces were attributable to ETS. Median daily and weekly exposures to VOCs, TVOCs, and RSP were calculated from the concentrations determined and tended to follow the trend: SH > NSH > SW > NSW. The home/work exposure differential (SH/SW) indicated that ETS exposure was higher for living with a smoker than for working with a smoker by a factor of 3.7 for RSP and ETS-RSP and 2.4 for VOCs and TVOCs.

Forty-nine nonsmoking married women participated in a home personal exposure study for 28 volatile organic compounds (VOCs) and total volatile organic compounds (TVOCs). The women were selected and classified according to 18 socioeconomic categories based on age (18–34 y, 35–49 y, 50–64 y), family income (<$25K, $25K-$40K, >$40K), and husband's smoking status. Of the 29 analytes, 21 demonstrated no statistically significant difference in concentration between nonsmoking and smoking homes. One VOC, trichloroethylene, was elevated in the nonsmoking homes and seven VOCs, benzene, styrene, pyridine, 2-picoline, 3-picoline, 3-ethylpyridine, and 3-ethenylpyridine were elevated in the smoking homes. A correlation matrix and a factor analysis indicate that benzene and styrene were not significantly correlated or associated with 3-ethyenylpyridine, a proposed vapor phase environmental tobacco smoke (ETS) marker. All of the nitrogenous bases were significantly correlated with 3-ethenylpyridine. Benzene, styrene, and TVOC were not significantly correlated with the number of cigarettes smoked; however, 3-ethenylpyridine was significantly correlated with the number of cigarettes smoked. A Pearson correlation analysis indicated that gas heat and smoking husband were significantly correlated with elevated benzene concentrations, but a multiple regression model for benzene accounted for less than 30% of the total variance. ETS variables accounted for only 8% of the total variance. In the smoking homes, an apportionment technique was evaluated for selected VOCs in order to determine the median percentage of each analyte attributable to ETS. The results, with percentages attributable to ETS were TVOC (5.5%), benzene (13.2%), styrene (12.6%), pyridine (40.7%), 2-picoline (67.1%), 3-picoline (90.1%), 4-picoline (37.2%), and 3-ethylpyridine (62.0%). Indoor air sources other than ETS were also identified for limonene, tetrachlorethylene, 1,4-dichlorobenzene, and alkylbenzenes.

Nicotine in environmental tobacco smoke (ETS) resides predominantly in the aerosol vapour phase as a result of evaporation from the particles of sidestream smoke. In true ETS (i. e., not concentrated or fresh sidestream smoke), the fraction of nicotine associated with the aerosol particulate phase is quite small, typically less than 5% of the total. Recently, some investigators have collected nicotine with sampling systems employing sorbent resin cartridges downstream from glass-fibre filters, and have attributed the nicotine retained on the glass-fibre filters to the particulate phase. The data reported here demonstrate that phase distributions and dynamics determined using glass-fibre filters are due to sampling system artefacts. Glass-fibre filters collect virtually all nicotine (vapour- and particulate-phase) at relatively short sampling intervals (1-2 min). The percentage of total nicotine trapped on the filter decreases with increasing sampling time. Using such a system, only that amount of total nicotine which exceeds the adsorptive capacity of the filter will break through and be collected by the sorbent medium. Attributing ETS particulate-phase nicotine to the quantity collected on a glass-fibre filter leads to erroneous conclusions regarding vapour-particulate phase dynamics.

Sensory ratings, respiratory behavior and eye blink rate were recorded in 11 nonsmokers exposed to a no-smoking (CONTROL) condition or to environmental tobacco smoke (ETS) from one of three kinds of cigarettes: a Kentucky reference (1R4F), an ultra-low tar (ULT) and one that heats tobacco (TEST).For each two-hour session in a controlled-environment room, two smokers “puffed” unlit cigarettes, for the CONTROL condition, or smoked 16 cigarettes to generate ETS (sidestream plus exhaled mainstream smoke). Concentrations of nicotine and respirable suspended particles (RSP) observed with the 1R4F and ULT cigarettes were 10- to 20-fold higher than those typically found in field sampling studies of office and restaurant smoking environments. The ULT and TEST cigarettes resulted in ETS analyte concentrations that were 77-100% and O-56%, respectively, of those observed with 1R4E Sensory ratings (odor, irritation, annoyance, acceptability) with the two tobacco-burning cigarettes were similar and were much greater than those recorded for the TEST or CONTROL conditions which were, in turn, rated similarly. Respiratory parameters (respiratory rate, tidal volume, expiratory time), which generally failed to discriminate the TEST and CONTROL conditions, were altered during exposure to ETS from the 1R4F and, to a lesser extent, the ULT cigarette. Eye blink rate was not significantly altered by ETS from any of the cigarettes.

Real-time data obtained with an atmospheric pressure chemical ionization mass spectrometer were used for both qualitative and quantitative evaluation of air cleaner performance. Differences among air cleaners were evaluated by performing ANOVA followed by a Bonferroni-normalized multiple comparison test on the average concentration of each analyte when the air cleaners were on and off. A mathematical model was developed and applied which permits air cleaner efficiencies and clean air delivery rates to be determined by performing a kinetic analysis of the real-time data for each analyte. This new method for determining clean air delivery rate is broadly applicable to any steady-state concentration data and does not require real-time data for application.

Several environmental tobacco smoke (ETS) markers were evaluated in a controlled environment test chamber. Ratios of the markers were determined at ventilation rates of 0-4 air changes/h and sampling durations of 30-360 min. Solanesol, ultraviolet particulate matter, and fluorescent particulate matter were good predictors of respirable suspended particle concentrations. 3-Ethenylpyridine concentrations correlated well with concentrations of gas-phase ETS components. The ratio of nicotine to both gas- and particulate-phase components is highly variable. As a result, the sole use of nicotine as an ETS marker may lead to significant errors in ETS exposure assessment.

A thermal desorption/gas chromatography/mass selective detection method using Tenax and Carbotrap multisorbent cartridges for the determination of 28 target volatile organic compounds (VOCs) is described. Techniques used for method validation include determination of limit of detection, limit of quantitation, repeatability, room temperature storage stability, breakthrough volume, and sampler collection efficiency. In addition, 3-ethenylpyridine (3-EP), a pyrolysis product of nicotine, is investigated as a suitable marker for environmental tobacco smoke (ETS). Experiments conducted in an environmental chamber at five different ventilation rates are used to determine 3-EP ratios to selected VOC analytes. These ratios are used to apportion the contribution of ETS to indoor air VOCs. Field results from four smoking and four nonsmoking homes are presented to illustrate the ET'S apportionment technique. Selected analyte apportionment indicates that ETS contributes a fraction of the target VOCs in homes with smoking activity.

A rapid gas chromatographic procedure with an analysis time of 5 min was developed for the determination of environmental nicotine collected on sorbent tubes containing XAD-4 resin. In validating this procedure, severe temporal losses of nicotine were observed for solutions in glass sample vials waiting in a queue in an autosampler tray for analysis. These losses were traced to adsorptive interactions of nicotine with the glass surface of the vials. The use of N-ethylnornicotine as the internal standard or the addition of triethylamine to all solutions were both successful in producing constant response ratios of nicotine to internal standard. Owing to the limited availability and expense of N-ethylnornicotine, our current procedure calls for the addition of triethylamine to all nicotine solutions at the 0.01% V/V level and the use of quinoline as internal standard.

Particulate mass concentration measurements have been made on environmental tobacco smoke (ETS) for the purpose of assessing the relative accuracy of several measurement procedures. ETS over a range of concentrations was generated in an environmental chamber by three methods. Mass concentration was measured by a gravimetric/spectrophotometric collection procedure, piezoelectric particle mass monitors, two nephelometry-based mass monitors, and a particle counting and sizing system. Two-hour average mass concentrations were determined by each method for concentrations ranging from very low levels up to those achieved by smoking one entire cigarette in the chamber. Statistical comparisons were made among procedures employing the gravimetric filter measurement as the basis for comparison. One nephelometry-based procedure gave significantly higher and the other significantly lower values than the filter determination. In one case, a correction for the difference between the particle mass density of the calibrating aerosol and that of ETS brought the nephelometry-based procedure into reasonable agreement with the filter measurement, while for the other, the correction did not resolve the discrepancy between methods. Statistically significant differences between the responses of two supposedly identical piezoelectric mass monitors were found, as was some slight dependence of the nephelometry- based procedures on method of ETS generation. In summary, the results indicate that significant errors can be expected if the instruments studied are used “off the shelf,” even for ETS generated under controlled laboratory conditions. Caution should be employed in field measurements where numerous sources and types of particulate matter can be encountered.