Effects of the culturally-sensitive comprehensive sex education programme among Thai secondary school students.

AIM: This paper reports on a study to evaluate the effectiveness of a culturally-sensitive comprehensive sex education programme among Thai secondary school students. BACKGROUND: Increasing number of adolescents in Thailand have been engaging in premarital sex. No theory-based, abstinence-oriented models of sex education have been evaluated in this population. METHOD: A quasi-experimental study was conducted in 2006-2007. Outcome measures included sexual behaviour, condom use, intention to refuse sex, intention to use condoms, and knowledge regarding sexually transmitted infections/human immunodeficiency virus/acquired immunodeficiency syndrome and pregnancy. FINDINGS: Students in the experimental group had lower levels of reported sexual intercourse at 3- and 6-month follow-ups, compared with those in control group (P < 0.01). Students participating in the programme had significantly greater intention to refuse sex in the future across time than controls (P < 0.05). Sexually active adolescents participating in the programme reported significantly lower frequencies of sexual intercourse across time than controls (P < 0.01). However, the programme did not influence consistent condom use (P > 0.05), although the intervention was associated with increased intention to use condoms (P < 0.01). Knowledge about sexually transmitted infections/human immunodeficiency virus/acquired immunodeficiency syndrome and pregnancy among students in the intervention group was significantly greater than that of the controls (P < 0.05). CONCLUSION: School nurses can play a major role by applying this kind of sex education programme. For nurse researchers, it would be useful to extend this research by considering alternative ways to foster condom use in the non-commercial partnerships that have become common among adolescents.

Bioavailability and trophic transfer of sediment-bound Ni and U in a southeastern wetland system.

Elemental composition of soil, herbaceous and woody plant species, and the muscle and liver tissue of two common small mammal species were determined in a wetland ecosystem contaminated with Ni and U from nuclear target processing activities at the Savannah River Site, Aiken, SC. Species studied were black willow ( Salix nigra L.), rushes ( Juncus effusus L.), marsh rice rat ( Oryzomys palustris), and cotton rat ( Sigmodon hispidus). Two mature trees were sampled around the perimeter of the former de facto settling basin, and transect lines sampling rushes and trapping small mammals were laid across the wetland area, close to a wooden spillway that previously enclosed the pond. Ni and U concentrations were elevated to contaminant levels; with a total concentration of 1,065 (+/- 54) mg kg(-1) U and 526.7 (+/-18.3) mg kg(-1) Ni within the soil. Transfer of contaminants into woody and herbaceous plant tissues was higher for Ni than for U, which appeared to remain bound to the outside of root tissues, with very little (0.03 +/- 0.001 mg kg(-1)) U detectable within the leaf tissues. This indicated a lower bioavailability of U than the cocontaminant Ni. Trees sampled from the drier margins of the pond area contained more Ni within their leaf tissues than the rushes sampled from the wetter floodplain area, with leaf tissues concentrations of Ni of approximately 75.5 (+/- 3.6) mg kg(-1) Ni. Ni concentrations were also elevated in small mammal tissues. Transfer factors of contaminants indicated that U bioavailability is negligable in this wetland ecosystem.

Environmental tobacco smoke in an unrestricted smoking workplace: area and personal exposure monitoring.

The objective of this investigation was to determine the extent of areal and day-to-day variability of stationary environmental tobacco smoke (ETS) concentrations in a single large facility where smoking was both prevalent and unrestricted, and to determine the degree of daily variation in the personal exposure levels of ETS constituents in the same facility. The subject facility was a relatively new four-story office building with an approximate volume of 1.3 million ft3. The exchange of outside air in the building was determined to be between 0.6 and 0.7 air changes per hour. Eighty-seven area samples (excluding background) were collected at 29 locations over the course of 6 days of sampling. Locations included offices and cubicles occupied by smokers and nonsmokers, common areas, and the computer and mail rooms. Twenty-four nonsmoking subjects wore personal sampling systems to collect breathing zone air samples on each of 3 days in succession. This generated a total of seventy-two 8-h time-weighted average (TWA) personal exposure samples. In all samples, respirable suspended particulate matter, ultraviolet light-absorbing and fluorescing particulate matter, solanesol, nicotine, and 3-ethenyl pyridine were determined. With the exception of a few locations, tobacco-specific airborne constituents were determined in all samples. Not surprisingly, areas with the highest ETS constituent concentrations were offices and cubicles of smokers. Median and 95th percentile concentrations for all area samples, excluding background, were determined to be 1.5 and 8.7 microg/m3 for nicotine, and 8.2 and 59 microg/m3 for ETS-specific particles (as solanesol-related particulate matter, Sol-PM), respectively. Personal exposure concentrations of ETS components were similar to those levels found in the area samples (median nicotine and Sol-PM concentrations were 1.24 and 7.1 microg/m3, respectively), but the range of concentrations was somewhat smaller. For example, the 95th percentile 8-h TWA nicotine and ETS-specific particle (as Sol-PM) concentrations were 3.58 and 21.9 microg/m3, respectively. Intrasubject variation of daily concentrations ranged from 20% to 60%, depending on the component. Self-reported proximity to smokers was supported by higher ETS concentrations determined from the personal monitors, but only to a modest extent. Although smoking was completely unrestricted inside the main office areas of the facility, ETS levels, either areal or from personal exposure measurements, were lower than those estimated by Occupational Safety and Health Administration to be present in such facilities.

Meeting data quality objectives with interval information.

Immunoassay test kits are promising technologies for measuring analytes under field conditions. Frequently, these field-test kits report the analyte concentrations as falling in an interval between minimum and maximum values. Many project managers use field-test kits only for screening purposes when characterizing waste sites because the results are presented as semiquantitative intervals. However, field-test kits that report results as intervals can also be used to make project-related decisions in compliance with false-rejection and false-acceptance decision error rates established during a quantitative data quality objective process. Sampling and analysis plans can be developed that rely on field-test kits to meet certain data needs of site remediation projects.

Factors associated with Army obstetricians-gynecologists' practice of HIV prevention education during routine gynecologic care.

The authors evaluate obstetricians-gynecologists' (OB-GYNs') anxiety about clinical uncertainty and patient, physician, and organizational factors associated with their selection of HIV-related educational activities for high-risk and low-risk written case simulations. A total of 117 U.S. Army OB-GYNs completed a mailed, anonymous questionnaire. Overall, informants were much less likely to educate in response to the low-risk simulation; however, more informants who were anxious about uncertainty were more likely to do so in a model that included supportive institutional policies, willingness to educate despite patient barriers, and comfort with the topic. OB-GYNs were more likely to educate in response to the high-risk simulation given greater willingness to discuss HIV despite organizational barriers, supportive policies, and comfort. Findings suggest a need to better understand the role that anxiety about uncertainty plays in HIV prevention and the need to promote organizational policies that support and remove barriers to clinically based education.

Environmental tobacco smoke in the nonsmoking section of a restaurant: a case study.

This study tested the concentrations of environmental tobacco smoke (ETS) components in a small restaurant/pub with smoking and nonsmoking areas-a facility outfitted with a heat-recovery ventilation system and directional airflow. The ETS levels in the nonsmoking area were compared with those in other similar restaurants/pubs where indoor smoking is altogether prohibited. The results indicate that ETS component concentrations in the nonsmoking section of the facility in question were not statistically different (P < 0.05) from those measured in similar facilities where smoking is prohibited. The regulatory implications of these findings are that ventilation techniques for restaurants/pubs with separate smoking and nonsmoking areas are capable of achieving nonsmoking area ETS concentrations that are comparable to those of similar facilities that prohibit smoking outright.

Determination of cocaine and heroin vapor pressures using commercial and illicit samples.

The establishment of drug vapor pressure reference values provides valuable information in the development of vapor sensing devices for drug detection. The purpose of this work was to determine equilibrium headspace vapor pressures for commercial and illicit drug samples for use in such applications. Samples of cocaine, both free base and hydrochloride forms, and heroin hydrochloride were evaluated. The procedure used to measure the vapor pressures was a modification of a previously published method. Vapor pressure values at 20 degrees C previously reported for cocaine free base range from 0.37 x 10(-7) to 1.20 x 10(-7) Torr. The vapor pressure value determined in this study was 2.96 x 10(-7) Torr. It is likely that the discrepancies are due to differences in experimental conditions, varying sources of samples, and uncertainty in the methodologies. When the values were compared for commercial (99% purity) and illicit (unknown purity) sources of cocaine free base, there were no statistical differences in the projected room temperature (20 degrees C) vapor pressure values. However, the commercial and illicit samples of cocaine hydrochloride did show statistical differences. Although no comparison was made with the vapor pressure values for a pure, commercial sample, the vapor pressures of heroin hydrochloride (81% purity) at various temperatures were determined using the method developed for cocaine and are reported in this paper.

Doses and lung burdens of environmental tobacco smoke constituents in nonsmoking workplaces.

This paper models nicotine dose and ultraviolet-absorbing particulate matter (UVPM) alveolar lung burden resulting from exposure to environmental tobacco smoke (ETS) for nonsmokers in workplaces where smoking was reported not to occur. Data were obtained from personal monitoring of ETS in 16 U.S. cities [Jenkins R.A., Guerin M.R., Palausky A., Counts R.W., Bayne C.K., and Dindal A.B. Determination of human exposure to environmental tobacco smoke (ETS): a study conducted in 16 U.S. cities. Draft final report by Oak Ridge National Laboratory for Center for Indoor Air Research, Linthicum, MD, 1996a; Jenkins R.A., Palausky A., Counts R.W., Bayne C.K., Dindal A.B., and Guerin M.R. Exposure to environmental tobacco smoke in sixteen cities in the United States as determined by personal breathing zone air sampling. J. Expos. Anal. Environ. Epidemiol. 1996b: 6(4): 473-502.]. This is a continuation of earlier analyses focusing on nonsmokers in smoking workplaces (SWs) [LaKind J.S., Graves C.G., Ginevan M.E., Jenkins R.A., Naiman D.Q., and Tardiff R.G. Exposure to environmental tobacco smoke in the workplace and the impact of away - from - work exposure. Risk Anal. 1999a: 19(3): 349-358; LaKind J.S., Jenkins R.A., Naiman D.Q., Ginevan M.E., Graves C.G., and Tardiff R.G. Use of environmental tobacco smoke constituents as markers for exposure. Risk Anal. 1999b: 19 (3): 359-373; LaKind J.S., Ginevan M.E., Naiman D.Q., James A.C., Jenkins R.A., Dourson M.L., Felter S.P., Graves C.G., and Tardiff R.G. Distribution of exposure concentrations and doses for constituents of environmental tobacco smoke. RiskAnal. 1999c: 19 (3): 375-390.]. Even though study participants characterized their workplaces as nonsmoking, some individuals reported observing cigarettes in the workplace. Individuals observing six or more cigarettes were excluded from the analysis on the grounds that they were in defacto SWs. Exposure to ETS was lower in nonsmoking than SWs, but even with this exclusion, exposure was not zero. Distributions were selected for each model input, and at least 2000 iterations of the model were made for each dose or lung burden characterization (e.g., for females, for males). In these nonsmoking workplaces (NSWs), neither nicotine nor UVPM concentrations were lognormally distributed. Hence, observed concentrations were used directly via bootstrap sampling (nicotine) or a constant number of times (UVPM) as input to the models. As in SWs, individuals from smoking homes (SHs) experienced greater exposure in NSWs to both nicotine and UVPM than did individuals from nonsmoking homes (NSH; P<0.001 ). The distributions of modeled nicotine dose and UVPM lung burden were highly skewed, with most individuals receiving relatively low exposure to ETS in the workplace. Comparing doses from NSWs modeled here to doses from SWs modeled previously, less difference between smoking and NSWs was apparent in UVPM levels than in nicotine levels. For average exposure, UVPM alveolar lung burdens were approximately 10-fold higher in smoking than NSWs, while average nicotine doses were 20-25 times higher in smoking than NSWs. These findings are in the range observed by other investigators and are partly explained by very low denominators in the ratios (i.e., very low levels experienced in NSWs). For upper bound exposure, the nonsmoking-to-smoking ratios remained about the same for UVPM. For nicotine, the upper bound ratios remained the same for people from NSHs but were halved for people from SHs.

Correlates of human immunodeficiency virus infection risk behavior in male attendees of a clinic for sexually transmitted disease.

Human immunodeficiency virus (HIV) infection risk behavior was evaluated in a cross-sectional survey of 400 male active-duty US Army personnel who presented at a sexually transmitted disease (STD) clinic with symptoms of acute urethritis. High-risk partners were common, and nearly one-quarter of the sample had previously had STDs. Logistic regression models examined correlates of HIV exposure risk, of inconsistent condom use, and of having partners with increased risk of HIV infection. Frequent partner turnover, sex "binging," negative attitudes toward condom use, and engaging in sex during military leaves were important correlates of risk. Individuals with HIV infection risk behavior generally were cognizant of their risk for HIV infection. Implications for intervention are discussed.

Reducing risk of sexually transmitted disease (STD) and human immunodeficiency virus infection in a military STD clinic: evaluation of a randomized preventive intervention trial.

Three single-session preventive interventions for reducing sexually transmitted disease (STD) and human immunodeficiency virus infection risk behaviors were evaluated with a sample of 400 men who attended a large military STD clinic. A quasi-experimental, pre-evaluation/postevaluation design was used, comparing standard clinic care alone versus standard care combined with 1 of 3 experimental interventions: health-risk appraisal, interactive video, and targeted situational behaviors. Questionnaire data were collected at baseline and during follow-up visits at 2 weeks and 2 months. Findings indicated that the health-risk appraisal and interactive video increased adherence with clinic recommendations to abstain from sex (chi(2)3199=19.67; P<.001) and increased readiness to change "risky" partner-selection behavior (chi(2)2194=6.42; P<.04). Follow-up data suggested that STD-related risk behavior was particularly resistant to change but that the single-session intervention had some impact, which could be viewed as a "priming" effect that enhances multisession interventions.

Features of urethritis in a cohort of male soldiers.

Of 400 cases of urethritis in male soldiers enrolled in a behavioral intervention project, the etiology of 69% was defined at study enrollment, as well as the etiology of 72% of 25 repeated episodes involving 21 men during the first 78 days of active follow-up (5% of the cohort). Chlamydia trachomatis (36%), Neisseria gonorrhoeae (34%), and Ureaplasma urealyticum (19%) were the most common causes of infection identified at enrollment and during subsequent visits (44%, 28%, and 12%, respectively). By univariate analysis, patients with repeated infection ("repeaters") were significantly more likely to report a history of sexually transmitted disease (STD; relative risk [RR], 3) and sex with sex workers (RR, 4) than were nonrepeaters. By multivariate analysis, only STD history was significant (RR, 2.8). Characteristics of repeaters in this cohort suggest that specific patterns may be used to establish screening "profiles" of potential repeaters, by which such individuals might be targeted for aggressive intervention at the time of the initial diagnosis.

Determination of exposure to environmental tobacco smoke in restaurant and tavern workers in one US city.

Approximately 173 subjects employed as waiters, waitresses, or bartenders in the Knoxville, TN, Standard Metropolitan Statistical Area collected a sample of air from their breathing zone while at their workplace for one shift. In addition, area samples were placed near the work spaces of many of the subjects. Collected samples were analyzed for respirable suspended particulate matter (RSPM), ultraviolet-absorbing and fluorescing particulate matter, solanesol, 3-ethenyl pyridine (3-EP), and nicotine. Saliva samples were collected from the subjects prior to and within 24 h following their work shift, to confirm their non-smoking status. The range of concentrations of environmental tobacco smoke (ETS) constituents encountered was considerable, e.g., for nicotine, from undetectable to more than 100 microg/m3. However, the highest RSP levels observed were considerably lower than OSHA workplace standards. Distributions of ETS concentrations suggest that there are two "ETS exposure" types of bartenders: those that work in single room bars and those that work in larger, multiroom restaurant/bars. Personal exposure to ETS of the former group was ca. 10x greater than those of the latter group, who were exposed to ETS levels more comparable to those encountered by wait staff. Exposure (concentration x duration) differences between wait staff and workers in other types of unrestricted smoking environments reported in other studies suggest that exposures in the restaurant environment may be more difficult to assess than originally considered. Salivary cotinine levels indicated that for those subjects living in smoking homes, ETS exposures outside the workplace are at least as important as those in the workplace.

Willingness to participate in HIV-1 vaccine trials among young Thai men.

OBJECTIVES: Willingness to participate in HIV-1 vaccine trials and associated factors were investigated in a sample of 2670 Royal Thai Army conscripted recruits. METHODS: Self administered questionnaires were used. Data were collected during the final visit of a longitudinal cohort study of HIV-1 epidemiology. Cross sectional analysis of data from this visit was performed. RESULTS: 32% of the respondents reported they would "definitely" join an HIV-1 vaccine trial. Greater willingness was associated with perceived risk of HIV-1 infection and a desire to help Thai society, although tangible incentives and intentions to reduce condom use in a vaccine trial also were associated with increased willingness. Concerns about physical harm and anticipated social pressure from family not to join were the most substantial impediments to willingness. Concerns about "social harm" (for example, participation would give appearance of having AIDS virus, a partner might refuse sex) also appeared to inhibit interest in joining trials and approached significance. CONCLUSIONS: Willingness to participate was somewhat greater than in other investigations of non-injection drug user (IDU) cohorts in Thailand, with fewer concerns expressed about physical harm. Motivations appear to involve tradeoffs among perceived risk, anticipated social pressure, altruism, and tangible rewards. The absence of significant problems associated with vaccine trials to date, along with the presence of educational interventions in the study may help explain the lower level of concerns here relative to other Thai studies.

Personal exposure to environmental tobacco smoke: salivary cotinine, airborne nicotine, and nonsmoker misclassification.

A large study was conducted to assess exposure to environmental tobacco smoke (ETS) in a geographically dispersed study population using personal breathing zone air sampling and salivary cotinine levels. Approximately 100 self-reported nonsmoking subjects in each of 16 metropolitan areas were recruited for this investigation. Cumulative distributions of salivary cotinine levels for subjects in smoking and nonsmoking homes and workplaces exhibited a general trend of decreasing salivary cotinine levels with decreasing time spent in smoking environments. Median salivary cotinine levels for the four experimental cells in the study (product of smoking and nonsmoking home and workplaces) were comparable to those reported for a large national study of serum levels of cotinine (Third National Health and Nutrition Examination Survey, NHANES III), when the latter was corrected for expected differences between serum and saliva concentrations. However, the most highly exposed group in this study had a median salivary cotinine concentration approximately a factor of 2 greater than that of the comparable group in the NHANES III study. Misclassification rates, both simple (for self-reported nonsmokers) and complex (self-reported lifetime never smokers), were near the median of those reported for other studies. Estimated misclassification rates for self-reported lifetime never-smoking females are sufficiently high (2.95% using a discrimination level of 106 ng/ml) that, if used in the Environmental Protection Agency (EPA) risk assessment related to ETS and lung cancer, would place the lower 90% confidence interval (CI) for relative risk at nearly 1.00, i.e., no statistically significant increased risk. For the 263 most highly exposed subjects in the study whose self-reported nonsmoking status was accurate, the correlation between airborne exposure to nicotine and average salivary cotinine is so small, on an individual basis, that it makes the relationship useless for estimating exposure on a quantitative basis. When subjects are grouped according to likely categories of nicotine exposure, correlation between group median airborne nicotine exposure and salivary cotinine level increases dramatically. The comparison improves for the most highly exposed subjects, suggesting that such quantitative comparisons are useful for only those subjects who are exposed to the higher levels of ETS. However, airborne nicotine exposure for most of the subjects does not account for estimated systemic levels of nicotine, based on salivary cotinine levels.

Occupational exposure to environmental tobacco smoke: results of two personal exposure studies.

Personal monitoring is a more accurate measure of individual exposure to airborne constituents because it incorporates human activity patterns and collects actual breathing zone samples to which subjects are exposed. Two recent studies conducted by our laboratory offer perspective on occupational exposure to environmental tobacco smoke (ETS) from a personal exposure standpoint. In a study of nearly 1600 workers, levels of ETS were lower than or comparable to those in earlier studies. Limits on smoking in designated areas also acted to reduce overall exposure of workers. In facilities where smoking is permitted, ETS exposures are 10 to 20 times greater than in facilities in which smoking is banned. Service workers were exposed to higher levels of ETS than workers in white-collar occupations. For the narrower occupational category of waiters, waitresses, and bartenders, a second study in one urban location indicated that ETS levels to which wait staff are exposed are not considerably different from those exposure levels of subjects in the larger study who work in environments in which smoking is unrestricted. Bartenders were exposed to higher ETS levels, but there is a distinction between bartenders working in smaller facilities and those working in multiroom restaurant bars, with the former exposed to higher levels of ETS than the latter. In addition, ETS levels encountered by these more highly exposed workers are lower that those estimated by the Occupational Safety and Health Administration. Concomitant area monitoring in the smaller study suggests that area samples can only be used to estimate individual personal exposure to within an order of magnitude or greater.

Evaluation of behavioral and social issues among Thai HIV vaccine trial volunteers.

Behavioral and social issues were investigated in phase I/II preventive HIV vaccine trial volunteers in Thailand. These included risk behavior, HIV knowledge, distress, and social experiences associated with trial participation. Data were collected at baseline and at 4- and 8-month follow-up visits. Volunteers reported relatively low levels of risk behaviors at baseline and at the follow-up visits. About one fifth reported overtly negative reactions from family or friends. No problems with discrimination in employment, health care, or insurance were reported. Findings add to the evidence suggesting the feasibility of phase I/II prophylactic HIV vaccine trials with low-risk volunteers in Thailand.

Exposure to environmental tobacco smoke in the workplace and the impact of away-from-work exposure.

Concentrating on exposure in workplaces where smoking occurs, we examined environmental tobacco smoke (ETS)-related concentration data from the 16-City Study. This study involved a large population of nonsmokers, used personal monitors, and encompassed a wide selection of ETS-related constituents. This first article in a series of three describes the 16-City Study, considers the impact of demographic variables, and concludes that these variables did not explain differences in exposure to ETS. We compared 16-City Study concentrations obtained in the workplace to previously reported workplace concentrations and determined that data from this study were representative of current ETS exposure in nonmanufacturing workplaces where smoking occurs. Considering factors other than demographic factors, we found that, not surprisingly, the number of cigarettes observed in the workplace had an impact on exposure concentrations. Finally, we compared people from homes where smoking occurs with people from nonsmoking homes and found that people from smoking homes observed more smoking in the workplace and experienced higher concentrations of ETS-related compounds in the workplace, even when they observed the same number of cigarettes being smoked in the workplace. In two subsequent articles in this series, we discuss relationships between various ETS markers and provide estimates of distributions of doses to nonsmoking workers employed in workplaces where smoking occurs.

Use of environmental tobacco smoke constituents as markers for exposure.

The 16-City Study analyzed for gas-phase environmental tobacco smoke (ETS) constituents (nicotine, 3-ethenyl pyridine [3-EP], and myosmine) and for particulate-phase constituents (respirable particulate matter [RSP], ultraviolet-absorbing particulate matter [UVPM], fluorescing particulate matter [FPM], scopoletin, and solanesol). In this second of three articles, we discuss the merits of each constituent as a marker for ETS and report pair-wise comparisons of the markers. Neither nicotine nor UVPM were good predictors for RSP. However, nicotine and UVPM were good qualitative predictors of each other. Nicotine was correlated with other gas-phase constituents. Comparisons between UVPM and other particulate-phase constituents were performed. Its relation with FPM was excellent, with UVPM approximately 1 1/2 times FPM. The correlation between UVPM and solanesol was good, but the relationship between the two was not linear. The relation between UVPM and scopoletin was not good, largely because of noise in the scopoletin measures around its limit of detection. We considered the relation between nicotine and saliva continine, a metabolite of nicotine. The two were highly correlated on the group level. That is, for each cell (smoking home and work, smoking home but nonsmoking work, and so forth), there was high correlation between average continine and 24-hour time-weighted average (TWA) nicotine concentrations. However, on the individual level, the correlations, although significant, were not biologically meaningful. A consideration of cotinine and nicotine or 3-EP on a subset of the study whose only exposure to ETS was exclusively at work or exclusively at home showed that home exposure was a more important source of ETS than work exposure.

Distribution of exposure concentrations and doses for constituents of environmental tobacco smoke.

The ultimate goal of the research reported in this series of three articles is to derive distributions of doses of selected environmental tobacco smoke (ETS)-related chemicals for nonsmoking workers. This analysis uses data from the 16-City Study collected with personal monitors over the course of one workday in workplaces where smoking occurred. In this article, we describe distributions of ETS chemical concentrations and the characteristics of those distributions (e.g., whether the distribution was log normal for a given constituent) for the workplace exposure. Next, we present population parameters relevant for estimating dose distributions and the methods used for estimating those dose distributions. Finally, we derive distributions of doses of selected ETS-related constituents obtained in the workplace for people in smoking work environments. Estimating dose distributions provided information beyond the usual point estimate of dose and showed that the preponderance of individuals exposed to ETS in the workplace were exposed at the low end of the dose distribution curve. The results of this analysis include estimations of hourly maxima and time-weighted average (TWA) doses of nicotine from workplace exposures to ETS (extrapolated from 1 day to 1 week) and doses derived from modeled lung burdens of ultraviolet-absorbing particulate matter (UVPM) and solanesol resulting from workplace exposures to ETS (extrapolated from 1 day to 1 year).