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Since 1973 the legislated constitutional right to abortion has produced a political dichotomy (anti-abortion versus pro-abortion) within the United States, even while witnessing a gradual decline in the rate of abortions. A third paradigm, moral stewardship, is advanced as an effective means to ameliorate this social divisiveness. Incorporating the concept of stewardship into deliberations of pregnancy termination would require recognition, through fact-based education programs, of the life circumstances that prompt the consideration to terminate a pregnancy. Based on collective responsibility, policies, and programs are needed to foster social justice for parents and for the offspring brought to term, without creating excessive burdens on women faced with an unwanted pregnancy. Moral stewardship is perceived as humanitarian to family and community and advantageous to society overall. It also offers a serious opportunity to reshape our society from divisiveness to inclusiveness, and to guide science policy judgment that enhances and strengthens social justice.

Methyl tertiary butyl ether (MTBE) can enter surface water and groundwater through wet atmospheric deposition or as a result of fuel leaks and spills. About 30% of the U.S. population lives in areas where MTBE is in regular use. Ninety‐five percent of this population is unlikely to be exposed to MTBE in tap water at concentrations exceeding 2 ppb, and most will be exposed to concentrations that are much lower and may be zero. About 5% of this population may be exposed to higher levels of MTBE in tap water, resulting from fuel tank leaks and spills into surface or groundwater used for potable water supplies. This paper describes the concentration ranges found and anticipated in surface and groundwater, and estimates the distribution of doses experienced by humans using water containing MTBE to drink, prepare food, and shower/bathe. The toxic properties (including potency) of MTBE when ingested, inhaled, and in contact with the skin are summarized. Using a range of human toxic potency values derived from animal studies, margins of exposure (MOE) associated with alternative chronic exposure scenarios are estimated to range from 1700 to 140,000. Maximum concentrations of MTBE in tap water anticipated not to cause adverse health effects are determined to range from 700 to 14,000 ppb. The results of this analysis demonstrate that no health risks are likely to be associated with chronic and subchronic human exposures to MTBE in tap water. Although some individuals may be exposed to very high concentrations of MTBE in tap water immediately following a localized spill, these exposures are likely to be brief in duration due to large‐scale dilution and rapid volatilization of MTBE, the institution of emergency response and remediation measures to minimize human exposures, and the low taste and odor thresholds of MTBE which ensure that its presence in tap water is readily detected at concentrations well below the threshold for human injury.

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 discussthe 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 11/2 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 cotinine, 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 cotinine 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 whoseonly 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.

Concentrating on exposure in workplaces where smoking occurs, we examined environmental tobacco smoke (ETS)‐related concentration data from the 16‐City This study.(1,2) 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.

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 characteristicsof those distributions (e.g., whether the distribution was log normal for agiven 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 providedinformation 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).