Suchergebnisse

PDFs, CDFs, quantile functions, and Lorenz curves -- Summary inequality measures -- Choices of inequality measures -- Relative distribution methods -- Inference issues -- Analyzing inequality trends -- An illustrative application: inequality in income and wealth in the United States, 1991-2001

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).